+++ /dev/null
---- a/fs/Kconfig
-+++ b/fs/Kconfig
-@@ -182,6 +182,7 @@ source "fs/logfs/Kconfig"
- source "fs/cramfs/Kconfig"
- source "fs/squashfs/Kconfig"
- source "fs/freevxfs/Kconfig"
-+source "fs/mini_fo/Kconfig"
- source "fs/minix/Kconfig"
- source "fs/omfs/Kconfig"
- source "fs/hpfs/Kconfig"
---- a/fs/Makefile
-+++ b/fs/Makefile
-@@ -74,6 +74,7 @@ obj-$(CONFIG_SQUASHFS) += squashfs/
- obj-y += ramfs/
- obj-$(CONFIG_HUGETLBFS) += hugetlbfs/
- obj-$(CONFIG_CODA_FS) += coda/
-+obj-$(CONFIG_MINI_FO) += mini_fo/
- obj-$(CONFIG_MINIX_FS) += minix/
- obj-$(CONFIG_FAT_FS) += fat/
- obj-$(CONFIG_BFS_FS) += bfs/
---- /dev/null
-+++ b/fs/mini_fo/aux.c
-@@ -0,0 +1,577 @@
-+/*
-+ * Copyright (c) 1997-2003 Erez Zadok
-+ * Copyright (c) 2001-2003 Stony Brook University
-+ *
-+ * For specific licensing information, see the COPYING file distributed with
-+ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
-+ *
-+ * This Copyright notice must be kept intact and distributed with all
-+ * fistgen sources INCLUDING sources generated by fistgen.
-+ */
-+/*
-+ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
-+ *
-+ * This program is free software; you can redistribute it and/or
-+ * modify it under the terms of the GNU General Public License
-+ * as published by the Free Software Foundation; either version
-+ * 2 of the License, or (at your option) any later version.
-+ */
-+/*
-+ * $Id$
-+ */
-+
-+#ifdef HAVE_CONFIG_H
-+# include <config.h>
-+#endif
-+
-+#include "fist.h"
-+#include "mini_fo.h"
-+
-+/* check if file exists in storage */
-+int exists_in_storage(dentry_t *dentry)
-+{
-+ check_mini_fo_dentry(dentry);
-+ if(dtost(dentry) == MODIFIED || dtost(dentry) == CREATED || dtost(dentry) == DEL_REWRITTEN)
-+ return 1;
-+ return 0;
-+}
-+
-+/* check if dentry is in an existing state */
-+int is_mini_fo_existant(dentry_t *dentry)
-+{
-+ check_mini_fo_dentry(dentry);
-+
-+ if(dtost(dentry) == DELETED || dtost(dentry) == NON_EXISTANT)
-+ return 0;
-+ else
-+ return 1;
-+}
-+
-+/*
-+ * This function will create a negative storage dentry for
-+ * dentry, what is required for many create like options.
-+ * It will create the storage structure if necessary.
-+ */
-+int get_neg_sto_dentry(dentry_t *dentry)
-+{
-+ int err = 0;
-+ unsigned int len;
-+ const unsigned char *name;
-+
-+ if(!dentry ||
-+ !dtopd(dentry) ||
-+ !(dtost(dentry) == UNMODIFIED ||
-+ dtost(dentry) == NON_EXISTANT ||
-+ dtost(dentry) == DELETED)) {
-+ printk(KERN_CRIT "mini_fo: get_neg_sto_dentry: invalid dentry passed.\n");
-+ err = -1;
-+ goto out;
-+ }
-+ /* Have we got a neg. dentry already? */
-+ if(dtohd2(dentry)) {
-+ err = 0;
-+ goto out;
-+ }
-+ if(dtost(dentry->d_parent) == UNMODIFIED) {
-+ /* build sto struct */
-+ err = build_sto_structure(dentry->d_parent->d_parent, dentry->d_parent);
-+ if(err ||
-+ dtost(dentry->d_parent) != MODIFIED) {
-+ printk(KERN_CRIT "mini_fo: get_neg_sto_dentry: ERROR building sto structure.\n");
-+ err = -1;
-+ goto out;
-+ }
-+ }
-+
-+ len = dentry->d_name.len;
-+ name = dentry->d_name.name;
-+
-+ dtohd2(dentry) =
-+ lookup_one_len(name, dtohd2(dentry->d_parent), len);
-+
-+ out:
-+ return err;
-+}
-+
-+int check_mini_fo_dentry(dentry_t *dentry)
-+{
-+ ASSERT(dentry != NULL);
-+ ASSERT(dtopd(dentry) != NULL);
-+ ASSERT((dtohd(dentry) != NULL) || (dtohd2(dentry) != NULL));
-+
-+/* if(dtost(dentry) == MODIFIED) { */
-+/* ASSERT(dentry->d_inode != NULL); */
-+/* ASSERT(dtohd(dentry) != NULL); */
-+/* ASSERT(dtohd(dentry)->d_inode != NULL); */
-+/* ASSERT(dtohd2(dentry) != NULL); */
-+/* ASSERT(dtohd2(dentry)->d_inode != NULL); */
-+/* } */
-+/* else if(dtost(dentry) == UNMODIFIED) { */
-+/* ASSERT(dentry->d_inode != NULL); */
-+/* ASSERT( */
-+/* } */
-+ return 0;
-+}
-+
-+int check_mini_fo_file(file_t *file)
-+{
-+ ASSERT(file != NULL);
-+ ASSERT(ftopd(file) != NULL);
-+ ASSERT(file->f_dentry != NULL);
-+
-+ /* violent checking, check depending of state and type
-+ * if(S_ISDIR(file->f_dentry->d_inode->i_mode)) {}
-+ */
-+ ASSERT((ftohf(file) != NULL) || (ftohf2(file) != NULL));
-+ return 0;
-+}
-+
-+int check_mini_fo_inode(inode_t *inode)
-+{
-+ ASSERT(inode != NULL);
-+ ASSERT(itopd(inode) != NULL);
-+ ASSERT((itohi(inode) != NULL) || (itohi2(inode) != NULL));
-+ return 0;
-+}
-+
-+/*
-+ * will walk a base path as provided by get_mini_fo_bpath and return
-+ * the (hopefully ;-) ) positive dentry of the renamed base dir.
-+ *
-+ * This does some work of path_init.
-+ */
-+dentry_t *bpath_walk(super_block_t *sb, char *bpath)
-+{
-+ int err;
-+ struct vfsmount *mnt;
-+ struct nameidata nd;
-+
-+ /* be paranoid */
-+ if(!bpath || bpath[0] != '/') {
-+ printk(KERN_CRIT "mini_fo: bpath_walk: Invalid string.\n");
-+ return NULL;
-+ }
-+ if(!sb || !stopd(sb)) {
-+ printk(KERN_CRIT "mini_fo: bpath_walk: Invalid sb.\n");
-+ return NULL;
-+ }
-+
-+ /* fix this: how do I reach this lock?
-+ * read_lock(¤t->fs->lock); */
-+ mnt = mntget(stopd(sb)->hidden_mnt);
-+ /* read_unlock(¤t->fs->lock); */
-+
-+ err = vfs_path_lookup(mnt->mnt_root, mnt, bpath+1, 0, &nd);
-+
-+ /* validate */
-+ if (err || !nd.dentry || !nd.dentry->d_inode) {
-+ printk(KERN_CRIT "mini_fo: bpath_walk: path_walk failed.\n");
-+ return NULL;
-+ }
-+ return nd.dentry;
-+}
-+
-+
-+/* returns the full path of the basefile incl. its name */
-+int get_mini_fo_bpath(dentry_t *dentry, char **bpath, int *bpath_len)
-+{
-+ char *buf_walker;
-+ int len = 0;
-+ dentry_t *sky_walker;
-+
-+ if(!dentry || !dtohd(dentry)) {
-+ printk(KERN_CRIT "mini_fo: get_mini_fo_bpath: invalid dentry passed.\n");
-+ return -1;
-+ }
-+ sky_walker = dtohd(dentry);
-+
-+ do {
-+ len += sky_walker->d_name.len + 1 ; /* 1 for '/' */
-+ sky_walker = sky_walker->d_parent;
-+ } while(sky_walker != stopd(dentry->d_inode->i_sb)->base_dir_dentry);
-+
-+ /* 1 to oil the loop */
-+ *bpath = (char*) kmalloc(len + 1, GFP_KERNEL);
-+ if(!*bpath) {
-+ printk(KERN_CRIT "mini_fo: get_mini_fo_bpath: out of mem.\n");
-+ return -1;
-+ }
-+ buf_walker = *bpath+len; /* put it on last char */
-+ *buf_walker = '\n';
-+ sky_walker = dtohd(dentry);
-+
-+ do {
-+ buf_walker -= sky_walker->d_name.len;
-+ strncpy(buf_walker,
-+ sky_walker->d_name.name,
-+ sky_walker->d_name.len);
-+ *(--buf_walker) = '/';
-+ sky_walker = sky_walker->d_parent;
-+ } while(sky_walker != stopd(dentry->d_inode->i_sb)->base_dir_dentry);
-+
-+ /* bpath_len doesn't count newline! */
-+ *bpath_len = len;
-+ return 0;
-+}
-+
-+int mini_fo_cp_cont(dentry_t *tgt_dentry, struct vfsmount *tgt_mnt,
-+ dentry_t *src_dentry, struct vfsmount *src_mnt)
-+{
-+ void *buf;
-+ mm_segment_t old_fs;
-+ file_t *tgt_file;
-+ file_t *src_file;
-+ int bytes, len, tmp, err;
-+ err = 0;
-+
-+ if(!(tgt_dentry->d_inode && src_dentry->d_inode)) {
-+ printk(KERN_CRIT "mini_fo_cp_cont: ERROR, neg. dentry passed.\n");
-+ err = -EINVAL;
-+ goto out;
-+ }
-+
-+ dget(tgt_dentry);
-+ dget(src_dentry);
-+ mntget(tgt_mnt);
-+ mntget(src_mnt);
-+
-+ /* open file write only */
-+ tgt_file = dentry_open(tgt_dentry, tgt_mnt, 0x1);
-+ if(!tgt_file || IS_ERR(tgt_file)) {
-+ printk(KERN_CRIT "mini_fo_cp_cont: ERROR opening target file.\n");
-+ err = PTR_ERR(tgt_file);
-+ goto out_err;
-+ }
-+
-+ /* open file read only */
-+ src_file = dentry_open(src_dentry, src_mnt, 0x0);
-+ if(!src_file || IS_ERR(src_file)) {
-+ printk(KERN_CRIT "mini_fo_cp_cont: ERROR opening source file.\n");
-+ err = PTR_ERR(src_file);
-+
-+ /* close target file */
-+ fput(tgt_file);
-+ goto out_err;
-+ }
-+
-+ /* check if the filesystem(s) support read respective write */
-+ if(!src_file->f_op->read || !tgt_file->f_op->write) {
-+ printk(KERN_CRIT "mini_fo_cp_cont: ERROR, no fs read or write support.\n");
-+ err = -EPERM;
-+ goto out_close;
-+ }
-+
-+ /* allocate a page for transfering the data */
-+ buf = (void *) __get_free_page(GFP_KERNEL);
-+ if(!buf) {
-+ printk(KERN_CRIT "mini_fo_cp_cont: ERROR, out of kernel mem.\n");
-+ goto out_err;
-+ }
-+
-+ tgt_file->f_pos = 0;
-+ src_file->f_pos = 0;
-+
-+ old_fs = get_fs();
-+ set_fs(KERNEL_DS);
-+
-+ /* Doing this I assume that a read operation will return a full
-+ * buffer while there is still data to read, and a less than
-+ * full buffer when all data has been read.
-+ */
-+ bytes = len = PAGE_SIZE;
-+ while(bytes == len) {
-+ bytes = src_file->f_op->read(src_file, buf, len,
-+ &src_file->f_pos);
-+ tmp = tgt_file->f_op->write(tgt_file, buf, bytes,
-+ &tgt_file->f_pos);
-+ if(tmp != bytes) {
-+ printk(KERN_CRIT "mini_fo_cp_cont: ERROR writing.\n");
-+ goto out_close_unset;
-+ }
-+ }
-+
-+ free_page((unsigned long) buf);
-+ set_fs(old_fs);
-+ fput(tgt_file);
-+ fput(src_file);
-+ goto out;
-+
-+ out_close_unset:
-+ free_page((unsigned long) buf);
-+ set_fs(old_fs);
-+
-+ out_close:
-+ fput(tgt_file);
-+ fput(src_file);
-+
-+ out_err:
-+ dput(tgt_dentry);
-+ dput(src_dentry);
-+
-+ /* mk: not sure if this need to be done */
-+ mntput(tgt_mnt);
-+ mntput(src_mnt);
-+
-+ out:
-+ return err;
-+}
-+
-+/* mk:
-+ * ndl (no-duplicate list) stuff
-+ * This is used in mini_fo_readdir, to save the storage directory contents
-+ * and later when reading base, match them against the list in order
-+ * to avoid duplicates.
-+ */
-+
-+/* add a file specified by name and len to the ndl
-+ * Return values: 0 on success, <0 on failure.
-+ */
-+int ndl_add_entry(struct readdir_data *rd, const char *name, int len)
-+{
-+ struct ndl_entry *tmp_entry;
-+
-+ tmp_entry = (struct ndl_entry *)
-+ kmalloc(sizeof(struct ndl_entry), GFP_KERNEL);
-+ if(!tmp_entry) {
-+ printk(KERN_CRIT "mini_fo: ndl_add_entry: out of mem.\n");
-+ return -ENOMEM;
-+ }
-+ tmp_entry->name = (char*) kmalloc(len, GFP_KERNEL);
-+ if(!tmp_entry->name) {
-+ printk(KERN_CRIT "mini_fo: ndl_add_entry: out of mem.\n");
-+ return -ENOMEM;
-+ }
-+ strncpy(tmp_entry->name, name, len);
-+ tmp_entry->len = len;
-+
-+ list_add(&tmp_entry->list, &rd->ndl_list);
-+ rd->ndl_size++;
-+ return 0;
-+}
-+
-+/* delete all list entries and free memory */
-+void ndl_put_list(struct readdir_data *rd)
-+{
-+ struct list_head *tmp;
-+ struct ndl_entry *tmp_entry;
-+
-+ if(rd->ndl_size <= 0)
-+ return;
-+ while(!list_empty(&rd->ndl_list)) {
-+ tmp = rd->ndl_list.next;
-+ list_del(tmp);
-+ tmp_entry = list_entry(tmp, struct ndl_entry, list);
-+ kfree(tmp_entry->name);
-+ kfree(tmp_entry);
-+ }
-+ rd->ndl_size = 0;
-+}
-+
-+/* Check if a file specified by name and len is in the ndl
-+ * Return value: 0 if not in list, 1 if file is found in ndl.
-+ */
-+int ndl_check_entry(struct readdir_data *rd, const char *name, int len)
-+{
-+ struct list_head *tmp;
-+ struct ndl_entry *tmp_entry;
-+
-+ if(rd->ndl_size <= 0)
-+ return 0;
-+
-+ list_for_each(tmp, &rd->ndl_list) {
-+ tmp_entry = list_entry(tmp, struct ndl_entry, list);
-+ if(tmp_entry->len != len)
-+ continue;
-+ if(!strncmp(tmp_entry->name, name, len))
-+ return 1;
-+ }
-+ return 0;
-+}
-+
-+/* mk:
-+ * Recursive function to create corresponding directorys in the storage fs.
-+ * The function will build the storage directorys up to dentry.
-+ */
-+int build_sto_structure(dentry_t *dir, dentry_t *dentry)
-+{
-+ int err;
-+ dentry_t *hidden_sto_dentry;
-+ dentry_t *hidden_sto_dir_dentry;
-+
-+ if(dentry->d_parent != dir) {
-+ printk(KERN_CRIT "mini_fo: build_sto_structure: invalid parameter or meta data corruption [1].\n");
-+ return 1;
-+ }
-+
-+ if(dtost(dir) != MODIFIED) {
-+ err = build_sto_structure(dir->d_parent, dentry->d_parent);
-+ if(err)
-+ return err;
-+ }
-+
-+ /* ok, coming back again. */
-+ check_mini_fo_dentry(dentry);
-+ hidden_sto_dentry = dtohd2(dentry);
-+
-+ if(!hidden_sto_dentry) {
-+ /*
-+ * This is the case after creating the first
-+ * hidden_sto_dentry.
-+ * After one negative storage_dentry, all pointers to
-+ * hidden_storage dentries are set to NULL. We need to
-+ * create the negative dentry before we create the storage
-+ * file.
-+ */
-+ unsigned int len;
-+ const unsigned char *name;
-+ len = dtohd(dentry)->d_name.len;
-+ name = dtohd(dentry)->d_name.name;
-+ hidden_sto_dentry = lookup_one_len(name, dtohd2(dir), len);
-+ dtohd2(dentry) = hidden_sto_dentry;
-+ }
-+
-+ /* was: hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry); */
-+ hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+ /* lets be safe */
-+ if(dtohd2(dir) != hidden_sto_dir_dentry) {
-+ printk(KERN_CRIT "mini_fo: build_sto_structure: invalid parameter or meta data corruption [2].\n");
-+ return 1;
-+ }
-+
-+ /* check for errors in lock_parent */
-+ err = PTR_ERR(hidden_sto_dir_dentry);
-+ if(IS_ERR(hidden_sto_dir_dentry)) {
-+ printk(KERN_CRIT "mini_fo: build_sto_structure: lock_parent failed.\n");
-+ return err;
-+ }
-+
-+ err = vfs_mkdir(hidden_sto_dir_dentry->d_inode,
-+ hidden_sto_dentry,
-+ dir->d_inode->i_mode);
-+
-+ if(err) {
-+ printk(KERN_CRIT "mini_fo: build_sto_structure: failed to create storage dir [1].\n");
-+ /* was: unlock_dir(dir); */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&dir->d_inode->i_mutex);
-+#else
-+ up(&dir->d_inode->i_sem);
-+#endif
-+ dput(dir);
-+ return err;
-+ }
-+
-+ /* everything ok! */
-+ if(!dtohd2(dentry)->d_inode) {
-+ printk(KERN_CRIT "mini_fo: build_sto_structure: failed to create storage dir [2].\n");
-+ /* was: unlock_dir(dir); */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&dir->d_inode->i_mutex);
-+#else
-+ up(&dir->d_inode->i_sem);
-+#endif
-+ dput(dir);
-+ return 1;
-+ }
-+
-+ /* interpose the new inode and set new state */
-+ itohi2(dentry->d_inode) = igrab(dtohd2(dentry)->d_inode);
-+ dtopd(dentry)->state = MODIFIED;
-+
-+ /* initalize the wol list */
-+ itopd(dentry->d_inode)->deleted_list_size = -1;
-+ itopd(dentry->d_inode)->renamed_list_size = -1;
-+ meta_build_lists(dentry);
-+
-+ fist_copy_attr_all(dentry->d_inode, itohi2(dentry->d_inode));
-+ fist_copy_attr_timesizes(dir->d_inode,
-+ hidden_sto_dir_dentry->d_inode);
-+ dir->d_inode->i_nlink++;
-+ /* was: unlock_dir(hidden_sto_dir_dentry); */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+ dput(hidden_sto_dir_dentry);
-+ return 0;
-+}
-+
-+
-+#if 0 /* unused */
-+
-+/*
-+ * Read "len" bytes from "filename" into "buf".
-+ * "buf" is in kernel space.
-+ */
-+int
-+mini_fo_read_file(const char *filename, void *buf, int len)
-+{
-+ file_t *filp;
-+ mm_segment_t oldfs;
-+ int bytes;
-+ /* Chroot? Maybe NULL isn't right here */
-+ filp = filp_open(filename, O_RDONLY, 0);
-+ if (!filp || IS_ERR(filp)) {
-+ printk("mini_fo_read_file err %d\n", (int) PTR_ERR(filp));
-+ return -1; /* or do something else */
-+ }
-+
-+ if (!filp->f_op->read)
-+ return -2; /* file(system) doesn't allow reads */
-+
-+ /* now read len bytes from offset 0 */
-+ filp->f_pos = 0; /* start offset */
-+ oldfs = get_fs();
-+ set_fs(KERNEL_DS);
-+ bytes = filp->f_op->read(filp, buf, len, &filp->f_pos);
-+ set_fs(oldfs);
-+
-+ /* close the file */
-+ fput(filp);
-+
-+ return bytes;
-+}
-+
-+
-+
-+/*
-+ * Write "len" bytes from "buf" to "filename"
-+ * "buf" is in kernel space.
-+ */
-+int
-+mini_fo_write_file(const char *filename, void *buf, int len)
-+{
-+ file_t *filp;
-+ mm_segment_t oldfs;
-+ int bytes;
-+ /* Chroot? Maybe NULL isn't right here */
-+ filp = filp_open(filename, O_RDWR|O_CREAT, 0640);
-+ if (!filp || IS_ERR(filp)) {
-+ printk("mini_fo_write_file err %d\n", (int) PTR_ERR(filp));
-+ return -1; /* or do something else */
-+ }
-+
-+ if (!filp->f_op->write)
-+ return -2; /* file(system) doesn't allow writes */
-+
-+ /* now write len bytes from offset 0 */
-+ filp->f_pos = 0; /* start offset */
-+ oldfs = get_fs();
-+ set_fs(KERNEL_DS);
-+ bytes = filp->f_op->write(filp, buf, len, &filp->f_pos);
-+ set_fs(oldfs);
-+
-+ /* close the file */
-+ fput(filp);
-+
-+ return bytes;
-+}
-+
-+#endif /* unused */
-+
---- /dev/null
-+++ b/fs/mini_fo/ChangeLog
-@@ -0,0 +1,281 @@
-+2006-01-24 Markus Klotzbuecher <mk@mary.denx.de>
-+
-+ * Add tons of ugly ifdefs to Ed L. Cashin's mutex patch to
-+ retain backwards compatibility.
-+
-+2006-01-24 Ed L. Cashin <ecashin@coraid.com>
-+
-+ * Support for the new mutex infrastructure
-+ (7892f2f48d165a34b0b8130c8a195dfd807b8cb6)
-+
-+2005-10-15 Markus Klotzbuecher <mk@localhost.localdomain>
-+
-+ * Bugfix for a serious memory leak in mini_fo_follow_link.
-+
-+2005-09-21 Markus Klotzbuecher <mk@mary>
-+
-+ * new release 0.6.1
-+
-+ * fix of a compiler warning due to changes in 2.6.13
-+
-+2005-09-21 Klaus Wenninger <klaus.wenninger@siemens.com>
-+
-+ * file.c: readdir: fix for a bug that caused directory entries
-+ to show up twice when using storage filesystems such as
-+ minixfs or pramfs.
-+
-+2005-06-30 Eric Lammerts <eric@lammerts.org>
-+
-+ * fix for an oops when overwriting a binary thats beeing
-+ executed.
-+
-+2005-06-09 <mk@mary>
-+
-+ * Renamed overlay to mini_fo-overlay.
-+
-+ * Added mini_fo-merge script to allow merging of storage and base
-+ after making modifications.
-+
-+2005-05-22 root <mk@mary>
-+
-+ * Added overlay script that allows to easily mount mini_fo ontop
-+ of a given base directory
-+
-+2005-05-10 <mk@mary>
-+
-+ * inode.c: xattr functions return -EOPNOSUPP instead of
-+ -ENOSUPP, what confuses "ls -l"
-+
-+ * Changed license from LGPL to GPL.
-+
-+2005-05-08 root <mk@mary>
-+
-+ * Makefile: clean it up and added make install and make
-+ uninstall.
-+
-+2005-05-06 <mk@mary>
-+
-+ * merged devel branch back to main. [v0-6-0-pre3]
-+
-+ * removed unused files print.c and fist_ioctl. [devel-0-0-18]
-+
-+ * ioctl: removed fist_ioctl stuff, that is not needed for
-+ now.
-+
-+2005-05-03 <mk@mary>
-+
-+ * file.c: simplified mini_fo_open and mini_fo_setattr using
-+ new state changing functions. [devel-0-0-17]
-+
-+ * inode.c: Fixed getattr state bug (see below) in 2.4 function
-+ mini_fo_inode revalidate.
-+
-+ * inode.c: found an other bug in mini_fo_getattr. States are not
-+ reliable in this function, as a file can be opened, unlinked and
-+ the getattr function called. This results in a deleted dentry
-+ with an inode. Fix is to ignore states and simply use the inode
-+ available.
-+
-+2005-04-29 <mk@mary>
-+
-+ * file.c: Bugfix and cleanup in fasync and fsync. [devel-0-0-16]
-+
-+ * file.c: do not use mini_fo_lock so the generic version is
-+ used (I guess).
-+
-+ * inode.c: getattr, never call getattr on lower files, as this
-+ will cause the inum to change.
-+
-+ * inode.c: rename_reg_file renamed to rename_nondir, as it
-+ doesn't matter as long it't not a dir. Removed all
-+ rename_dev_file etc.
-+
-+ * tagged as devel-0-0-15
-+
-+ * inode.c: added support for chosing support for extended
-+ attrs at compile time by XATTR define in mini_fo.h .
-+
-+ * inode.c: fixed mini_fo_getattr to use mini_fo inode and not
-+ lower again, what avoids inode number changes that confused
-+ rm again. This is the proper solution.
-+
-+2005-04-24 <mk@mary>
-+
-+ * all files: updated Copyright notive to 2005. [devel-0-0-14]
-+
-+ * inode.c: fixed mini_fo_getattr to not change the inode
-+ number, even if lower files change.
-+
-+ * super.c: fixed a bug that caused deleted base file to show
-+ up suddenly after some time, or after creating a special
-+ file. The problem was that after some time or after special
-+ file creating sync_sb_inodes is called by the vfs, that
-+ called our mini_fo_put_inode. There was (wrongly) called
-+ __meta_put_lists, that nuked the lists, although the inode
-+ was going to continue its life. Moving __meta_put_lists to
-+ mini_fo_clear_inode, where an inode is really destroyed,
-+ solved the problem.
-+
-+
-+2005-04-23 <mk@mary>
-+
-+ * state.c, aux.c: more cleaning up and
-+ simplifications. [devel-0-0-13]
-+
-+ * inode.c: implemented mini_fo_getattr, that was required for
-+ 2.6 because inode_revalidate has been remove there, and the
-+ old "du" bug returned.
-+
-+
-+2005-04-20 <mk@mary>
-+
-+ * aux.c: get_neg_sto_dentry(): allow to be called for dentries
-+ in state UNMODIFIED, NON_EXISTANT _and_ DELETED.
-+
-+2005-04-19 <mk@mary>
-+
-+ * Fixed a bug under 2.6 that caused files deleted via mini_fo
-+ not to be deleted properly and therefore the fs filled up
-+ untill no memory was left. [devel-0-0-12]
-+
-+ * Added basic hard link support. This means that creating
-+ hardlinks will work, but existing ones will be treated as
-+ individual files. [devel-0-0-11]
-+
-+2005-04-17 <mk@mary>
-+
-+ * Bugfixes
-+
-+2005-04-13 root <mk@mary>
-+
-+ * Added file state.c for the state transition
-+ functions. Doesn't work very well yet, though...
-+
-+2005-04-12 <mk@mary>
-+
-+ * Porting to 2.6 started, which is easier than expected, also
-+ due to Olivier previous work.
-+
-+2005-04-08 <mk@mary>
-+
-+ * Fixed the bug that caused du to return invalid sizes of
-+ directory trees. The problem was that
-+ mini_fo_inode_revalidate didn't always copy the attributes
-+ from the base inode properly.
-+
-+2005-04-01 Markus Klotzbuecher <mk@chasey>
-+
-+ * Merged devel branch back to main trunk and updated the
-+ RELEASE notes. This will be 0-6-0-pre1.
-+
-+2005-03-31 Markus Klotzbuecher <mk@chasey>
-+
-+ * Fixed some bugs in rename_reg_file, that only showed up in
-+ the kernel compile test. Kernel compiles cleanly ontop of
-+ mini_fo, now also make mrproper etc. work. Seems pretty stable.
-+
-+2005-03-28 Markus Klotzbuecher <mk@chasey>
-+
-+ * Many, many directory renaming bugfixes and a lot of other
-+ cleanup. Dir renaming seems to work relatively stable.
-+
-+2005-03-22 Markus Klotzbuecher <mk@chasey>
-+
-+ * Finished implementing lightweight directory renaming. Some
-+ basic testing indicates it works fine.
-+ Next is to implement testcases for the testsuite and confirm
-+ everything is really working ok.
-+
-+2005-03-18 Markus Klotzbuecher <mk@chasey>
-+
-+ * Finished implementing meta.c stuff required for directory
-+ renaming.
-+
-+2005-03-17 Markus Klotzbuecher <mk@chasey>
-+
-+ * Fixed all compile warnings + an extremly old bug that
-+ somehow crept in while reworking the wol stuff to the META
-+ system. Turning on -Werror again... :-)
-+
-+ * Fixed some bugs in the new rename_reg_file function.
-+
-+ * Rewrote mini_fo rename and split it into several
-+ subfunctions, that handle the different types
-+ seperately. Rewrote the regular file function aswell, as it
-+ was implemented somewhat inefficient.
-+
-+2005-03-16 Markus Klotzbuecher <mk@chasey>
-+
-+ * Implemented new META subsystem, removed old WOL stuff in favor
-+ if it.
-+
-+ * After some basic testing everything seems ok...
-+
-+2005-03-11 Markus Klotzbuecher <mk@chasey>
-+
-+ * Renaming a non regular file caused trouble because I always
-+ tried to copy the contents. Now I only do this for regular
-+ files. mini_fo_rename still isn't implemented properly, renaming
-+ of device files, symlinks etc. results in a empty regular file
-+ instead of the proper type.
-+
-+ * Directory renaming suddenly works! What a surprise! I guess
-+ this is because renaming is implemented as making a copy and
-+ removing the original. Still this might not work
-+ everywhere...
-+
-+2005-03-09 Markus Klotzbuecher <mk@chasey>
-+
-+ * Bugfix, when a mini_fo directory that exists in storage
-+ (state: MODIFIED, CREATED and DEL_REWRITTEN) is deleted, a
-+ possibly existing WOL file contained in it needs to be
-+ deleted too.
-+
-+ * Starting cleanup: defined state names in order to get rid of
-+ the state numbers.
-+
-+2005-03-08 Markus Klotzbuecher <mk@chasey>
-+
-+ * Makefile fix, fist_ioctl was built against wrong sources if ARCH=um
-+
-+ * Fixed a bug in dentry.c, mini_fo_d_hash. In state 4 =
-+ DEL_REWRITTEN the hash was calculated from the base dentry,
-+ which was wrong and and caused assertions in
-+ __mini_fo_hidden_dentry to fail.
-+
-+2005-02-21 <mk@mary>
-+
-+ * Implemented directory deleting (inode.c)
-+
-+ * main.c: made mini_fo_parse_options a little more robust.
-+
-+2004-12-22 <mk@mary>
-+
-+ * Makefile cleanup and uml stuff, removed unneccessary files
-+
-+ * Created a new and hopefully more informative README
-+
-+ * CHANGELOG: created a new CHANGELOG and added old entries reversely
-+
-+
-+2004-10-24 Gleb Natapov <gleb@nbase.co.il>
-+
-+ * Fix: owner and group where not correctly copied from base to
-+ storage.
-+
-+
-+2004-10-05 Gleb Natapov <gleb@nbase.co.il>
-+
-+ * Implementation of fsync, fasync and lock mini_fo functions.
-+
-+
-+2004-09-29 Bob Lee <bob@pantasys.com>
-+
-+ * Fix of a serious pointer bug
-+
-+
-+2004-09-28 Gleb Natapov <gleb@nbase.co.il>
-+
-+ * Implementation of mini_fo_mknod and mini_fo_rename, support
-+ for device files.
-+
---- /dev/null
-+++ b/fs/mini_fo/dentry.c
-@@ -0,0 +1,244 @@
-+/*
-+ * Copyright (c) 1997-2003 Erez Zadok
-+ * Copyright (c) 2001-2003 Stony Brook University
-+ *
-+ * For specific licensing information, see the COPYING file distributed with
-+ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
-+ *
-+ * This Copyright notice must be kept intact and distributed with all
-+ * fistgen sources INCLUDING sources generated by fistgen.
-+ */
-+/*
-+ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
-+ *
-+ * This program is free software; you can redistribute it and/or
-+ * modify it under the terms of the GNU General Public License
-+ * as published by the Free Software Foundation; either version
-+ * 2 of the License, or (at your option) any later version.
-+ */
-+
-+/*
-+ * $Id$
-+ */
-+
-+#ifdef HAVE_CONFIG_H
-+# include <config.h>
-+#endif
-+
-+#include "fist.h"
-+#include "mini_fo.h"
-+
-+/*
-+ * THIS IS A BOOLEAN FUNCTION: returns 1 if valid, 0 otherwise.
-+ */
-+STATIC int
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+mini_fo_d_revalidate(dentry_t *dentry, struct nameidata *nd)
-+#else
-+mini_fo_d_revalidate(dentry_t *dentry, int flags)
-+#endif
-+{
-+ int err1 = 1; /* valid = 1, invalid = 0 */
-+ int err2 = 1;
-+ dentry_t *hidden_dentry;
-+ dentry_t *hidden_sto_dentry;
-+
-+
-+ check_mini_fo_dentry(dentry);
-+
-+ hidden_dentry = dtohd(dentry);
-+ hidden_sto_dentry = dtohd2(dentry);
-+
-+ if(hidden_dentry &&
-+ hidden_dentry->d_op &&
-+ hidden_dentry->d_op->d_revalidate) {
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ err1 = hidden_dentry->d_op->d_revalidate(hidden_dentry, nd);
-+#else
-+ err1 = hidden_dentry->d_op->d_revalidate(hidden_dentry, flags);
-+#endif
-+ }
-+ if(hidden_sto_dentry &&
-+ hidden_sto_dentry->d_op &&
-+ hidden_sto_dentry->d_op->d_revalidate) {
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ err2 = hidden_sto_dentry->d_op->d_revalidate(hidden_sto_dentry,
-+ nd);
-+#else
-+ err2 = hidden_sto_dentry->d_op->d_revalidate(hidden_sto_dentry,
-+ flags);
-+#endif
-+ }
-+
-+ /* mk: if one of the lower level dentries are valid,
-+ * the mini_fo dentry is too.
-+ */
-+ return (err1 || err2);
-+}
-+
-+
-+STATIC int
-+mini_fo_d_hash(dentry_t *dentry, qstr_t *name)
-+{
-+ int err = 0;
-+ dentry_t *hidden_dentry;
-+ dentry_t *hidden_sto_dentry;
-+
-+ /* hidden_dentry = mini_fo_hidden_dentry(dentry);
-+ * hidden_sto_dentry = mini_fo_hidden_sto_dentry(dentry); */
-+
-+ /* state 1, 3, 4, 5: build the hash for the storage dentry */
-+ if((dtopd(dentry)->state == MODIFIED) ||
-+ (dtopd(dentry)->state == CREATED) ||
-+ (dtopd(dentry)->state == DEL_REWRITTEN) ||
-+ (dtopd(dentry)->state == DELETED)) {
-+ hidden_sto_dentry = dtohd2(dentry);
-+ if(hidden_sto_dentry &&
-+ hidden_sto_dentry->d_op &&
-+ hidden_sto_dentry->d_op->d_hash) {
-+ err = hidden_sto_dentry->d_op->d_hash(hidden_sto_dentry, name);
-+ }
-+ goto out;
-+ }
-+ /* state 2: build the hash for the base dentry */
-+ if(dtopd(dentry)->state == UNMODIFIED) {
-+ hidden_dentry = dtohd(dentry);
-+ if(hidden_dentry &&
-+ hidden_dentry->d_op &&
-+ hidden_dentry->d_op->d_hash) {
-+ err = hidden_dentry->d_op->d_hash(hidden_dentry, name);
-+ }
-+ goto out;
-+ }
-+ /* state 6: build hash for the dentry that exists */
-+ if(dtopd(dentry)->state == NON_EXISTANT) {
-+ hidden_sto_dentry = dtohd2(dentry);
-+ if(hidden_sto_dentry &&
-+ hidden_sto_dentry->d_op &&
-+ hidden_sto_dentry->d_op->d_hash) {
-+ err = hidden_sto_dentry->d_op->d_hash(hidden_sto_dentry, name);
-+ goto out;
-+ }
-+ hidden_dentry = dtohd(dentry);
-+ if(hidden_dentry &&
-+ hidden_dentry->d_op &&
-+ hidden_dentry->d_op->d_hash) {
-+ err = hidden_dentry->d_op->d_hash(hidden_dentry, name);
-+ goto out;
-+ }
-+ }
-+
-+ printk(KERN_CRIT "mini_fo: d_hash: invalid state detected.\n");
-+
-+ out:
-+ return err;
-+}
-+
-+
-+STATIC int
-+mini_fo_d_compare(dentry_t *dentry, qstr_t *a, qstr_t *b)
-+{
-+ int err;
-+ dentry_t *hidden_dentry=NULL;
-+
-+ /* hidden_dentry = mini_fo_hidden_dentry(dentry); */
-+ if(dtohd2(dentry))
-+ hidden_dentry = dtohd2(dentry);
-+ else if(dtohd(dentry))
-+ hidden_dentry = dtohd(dentry);
-+
-+ if (hidden_dentry && hidden_dentry->d_op && hidden_dentry->d_op->d_compare) {
-+ err = hidden_dentry->d_op->d_compare(hidden_dentry, a, b);
-+ } else {
-+ err = ((a->len != b->len) || memcmp(a->name, b->name, b->len));
-+ }
-+
-+ return err;
-+}
-+
-+
-+int
-+mini_fo_d_delete(dentry_t *dentry)
-+{
-+ dentry_t *hidden_dentry;
-+ dentry_t *hidden_sto_dentry;
-+ int err = 0;
-+
-+ /* this could be a negative dentry, so check first */
-+ if (!dtopd(dentry)) {
-+ printk(KERN_CRIT "mini_fo_d_delete: negative dentry passed.\n");
-+ goto out;
-+ }
-+ hidden_dentry = dtohd(dentry);
-+ hidden_sto_dentry = dtohd2(dentry);
-+
-+ if(hidden_dentry) {
-+ if(hidden_dentry->d_op &&
-+ hidden_dentry->d_op->d_delete) {
-+ err = hidden_dentry->d_op->d_delete(hidden_dentry);
-+ }
-+ }
-+ if(hidden_sto_dentry) {
-+ if(hidden_sto_dentry->d_op &&
-+ hidden_sto_dentry->d_op->d_delete) {
-+ err = hidden_sto_dentry->d_op->d_delete(hidden_sto_dentry);
-+ }
-+ }
-+
-+ out:
-+ return err;
-+}
-+
-+
-+void
-+mini_fo_d_release(dentry_t *dentry)
-+{
-+ dentry_t *hidden_dentry;
-+ dentry_t *hidden_sto_dentry;
-+
-+
-+ /* this could be a negative dentry, so check first */
-+ if (!dtopd(dentry)) {
-+ printk(KERN_CRIT "mini_fo_d_release: no private data.\n");
-+ goto out;
-+ }
-+ hidden_dentry = dtohd(dentry);
-+ hidden_sto_dentry = dtohd2(dentry);
-+
-+ if(hidden_dentry) {
-+ /* decrement hidden dentry's counter and free its inode */
-+ dput(hidden_dentry);
-+ }
-+ if(hidden_sto_dentry) {
-+ /* decrement hidden dentry's counter and free its inode */
-+ dput(hidden_sto_dentry);
-+ }
-+
-+ /* free private data (mini_fo_dentry_info) here */
-+ kfree(dtopd(dentry));
-+ __dtopd(dentry) = NULL; /* just to be safe */
-+ out:
-+ return;
-+}
-+
-+
-+/*
-+ * we don't really need mini_fo_d_iput, because dentry_iput will call iput() if
-+ * mini_fo_d_iput is not defined. We left this implemented for ease of
-+ * tracing/debugging.
-+ */
-+void
-+mini_fo_d_iput(dentry_t *dentry, inode_t *inode)
-+{
-+ iput(inode);
-+}
-+
-+
-+struct dentry_operations mini_fo_dops = {
-+ d_revalidate: mini_fo_d_revalidate,
-+ d_hash: mini_fo_d_hash,
-+ d_compare: mini_fo_d_compare,
-+ d_release: mini_fo_d_release,
-+ d_delete: mini_fo_d_delete,
-+ d_iput: mini_fo_d_iput,
-+};
---- /dev/null
-+++ b/fs/mini_fo/file.c
-@@ -0,0 +1,713 @@
-+/*
-+ * Copyright (c) 1997-2003 Erez Zadok
-+ * Copyright (c) 2001-2003 Stony Brook University
-+ *
-+ * For specific licensing information, see the COPYING file distributed with
-+ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
-+ *
-+ * This Copyright notice must be kept intact and distributed with all
-+ * fistgen sources INCLUDING sources generated by fistgen.
-+ */
-+/*
-+ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
-+ *
-+ * This program is free software; you can redistribute it and/or
-+ * modify it under the terms of the GNU General Public License
-+ * as published by the Free Software Foundation; either version
-+ * 2 of the License, or (at your option) any later version.
-+ */
-+
-+/*
-+ * $Id$
-+ */
-+
-+#ifdef HAVE_CONFIG_H
-+# include <config.h>
-+#endif
-+
-+#include "fist.h"
-+#include "mini_fo.h"
-+#define ROUND_UP(x) (((x)+sizeof(long)-1) & ~(sizeof(long)-1))
-+
-+/*******************
-+ * File Operations *
-+ *******************/
-+
-+STATIC loff_t
-+mini_fo_llseek(file_t *file, loff_t offset, int origin)
-+{
-+ loff_t err;
-+ file_t *hidden_file = NULL;
-+
-+ if(S_ISDIR(file->f_dentry->d_inode->i_mode)) {
-+ /* Check if trying to llseek from a directory */
-+ err = -EISDIR;
-+ goto out;
-+ }
-+ if (ftopd(file) != NULL) {
-+ if(ftohf2(file)) {
-+ hidden_file = ftohf2(file);
-+ } else {
-+ hidden_file = ftohf(file);
-+ }
-+ }
-+
-+ /* always set hidden position to this one */
-+ hidden_file->f_pos = file->f_pos;
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ memcpy(&(hidden_file->f_ra),
-+ &(file->f_ra),
-+ sizeof(struct file_ra_state));
-+#else
-+ if (file->f_reada) { /* update readahead information if needed */
-+ hidden_file->f_reada = file->f_reada;
-+ hidden_file->f_ramax = file->f_ramax;
-+ hidden_file->f_raend = file->f_raend;
-+ hidden_file->f_ralen = file->f_ralen;
-+ hidden_file->f_rawin = file->f_rawin;
-+ }
-+#endif
-+ if (hidden_file->f_op && hidden_file->f_op->llseek)
-+ err = hidden_file->f_op->llseek(hidden_file, offset, origin);
-+ else
-+ err = generic_file_llseek(hidden_file, offset, origin);
-+
-+ if (err < 0)
-+ goto out;
-+
-+ if (err != file->f_pos) {
-+ file->f_pos = err;
-+ // ION maybe this?
-+ // file->f_pos = hidden_file->f_pos;
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-+ file->f_reada = 0;
-+#endif
-+ file->f_version++;
-+ }
-+
-+ out:
-+ return err;
-+}
-+
-+
-+/* mk: fanout capable */
-+STATIC ssize_t
-+mini_fo_read(file_t *file, char *buf, size_t count, loff_t *ppos)
-+{
-+ int err = -EINVAL;
-+ file_t *hidden_file = NULL;
-+ loff_t pos = *ppos;
-+
-+ if(S_ISDIR(file->f_dentry->d_inode->i_mode)) {
-+ /* Check if trying to read from a directory */
-+ /* printk(KERN_CRIT "mini_fo_read: ERROR: trying to read data from a directory.\n"); */
-+ err = -EISDIR;
-+ goto out;
-+ }
-+
-+ if (ftopd(file) != NULL) {
-+ if(ftohf2(file)) {
-+ hidden_file = ftohf2(file);
-+ } else {
-+ hidden_file = ftohf(file);
-+ }
-+ }
-+
-+ if (!hidden_file->f_op || !hidden_file->f_op->read)
-+ goto out;
-+
-+ err = hidden_file->f_op->read(hidden_file, buf, count, &pos);
-+ *ppos = pos;
-+
-+ if (err >= 0) {
-+ /* atime should also be updated for reads of size zero or more */
-+ fist_copy_attr_atime(file->f_dentry->d_inode,
-+ hidden_file->f_dentry->d_inode);
-+ }
-+
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-+ /*
-+ * MAJOR HACK
-+ * because pread() does not have any way to tell us that it is
-+ * our caller, then we don't know for sure if we have to update
-+ * the file positions. This hack relies on read() having passed us
-+ * the "real" pointer of its struct file's f_pos field.
-+ */
-+ if (ppos == &file->f_pos)
-+ hidden_file->f_pos = *ppos = pos;
-+ if (hidden_file->f_reada) { /* update readahead information if needed */
-+ file->f_reada = hidden_file->f_reada;
-+ file->f_ramax = hidden_file->f_ramax;
-+ file->f_raend = hidden_file->f_raend;
-+ file->f_ralen = hidden_file->f_ralen;
-+ file->f_rawin = hidden_file->f_rawin;
-+ }
-+#else
-+ memcpy(&(file->f_ra),&(hidden_file->f_ra),sizeof(struct file_ra_state));
-+#endif
-+
-+ out:
-+ return err;
-+}
-+
-+
-+/* this mini_fo_write() does not modify data pages! */
-+STATIC ssize_t
-+mini_fo_write(file_t *file, const char *buf, size_t count, loff_t *ppos)
-+{
-+ int err = -EINVAL;
-+ file_t *hidden_file = NULL;
-+ inode_t *inode;
-+ inode_t *hidden_inode;
-+ loff_t pos = *ppos;
-+
-+ /* mk: fan out: */
-+ if (ftopd(file) != NULL) {
-+ if(ftohf2(file)) {
-+ hidden_file = ftohf2(file);
-+ } else {
-+ /* This is bad! We have no storage file to write to. This
-+ * should never happen because if a file is opened for
-+ * writing, a copy should have been made earlier.
-+ */
-+ printk(KERN_CRIT "mini_fo: write : ERROR, no storage file to write.\n");
-+ err = -EINVAL;
-+ goto out;
-+ }
-+ }
-+
-+ inode = file->f_dentry->d_inode;
-+ hidden_inode = itohi2(inode);
-+ if(!hidden_inode) {
-+ printk(KERN_CRIT "mini_fo: write: no sto inode found, not good.\n");
-+ goto out;
-+ }
-+
-+ if (!hidden_file->f_op || !hidden_file->f_op->write)
-+ goto out;
-+
-+ /* adjust for append -- seek to the end of the file */
-+ if (file->f_flags & O_APPEND)
-+ pos = inode->i_size;
-+
-+ err = hidden_file->f_op->write(hidden_file, buf, count, &pos);
-+
-+ /*
-+ * copy ctime and mtime from lower layer attributes
-+ * atime is unchanged for both layers
-+ */
-+ if (err >= 0)
-+ fist_copy_attr_times(inode, hidden_inode);
-+
-+ *ppos = pos;
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-+ /*
-+ * XXX: MAJOR HACK
-+ *
-+ * because pwrite() does not have any way to tell us that it is
-+ * our caller, then we don't know for sure if we have to update
-+ * the file positions. This hack relies on write() having passed us
-+ * the "real" pointer of its struct file's f_pos field.
-+ */
-+ if (ppos == &file->f_pos)
-+ hidden_file->f_pos = *ppos = pos;
-+#endif
-+ /* update this inode's size */
-+ if (pos > inode->i_size)
-+ inode->i_size = pos;
-+
-+ out:
-+ return err;
-+}
-+
-+/* Global variable to hold a file_t pointer.
-+ * This serves to allow mini_fo_filldir function to know which file is
-+ * beeing read, which is required for two reasons:
-+ *
-+ * - be able to call wol functions in order to avoid listing deleted
-+ * base files.
-+ * - if we're reading a directory which is in state 1, we need to
-+ * maintain a list (in mini_fo_filldir) of which files allready
-+ * have been copied to userspace,to detect files existing in base
-+ * and storage and not list them twice.
-+ */
-+filldir_t mini_fo_filldir_orig;
-+file_t *mini_fo_filldir_file;
-+
-+/* mainly copied from fs/readdir.c */
-+STATIC int
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
-+mini_fo_filldir(void * __buf, const char * name, int namlen, loff_t offset,
-+ u64 ino, unsigned int d_type)
-+#else
-+mini_fo_filldir(void * __buf, const char * name, int namlen, loff_t offset,
-+ ino_t ino, unsigned int d_type)
-+#endif
-+{
-+ struct getdents_callback * buf = (struct getdents_callback *) __buf;
-+ file_t* file = mini_fo_filldir_file;
-+
-+ /* In theses states we filter meta files in storage (WOL) */
-+ if(file && (dtopd(file->f_dentry)->state == MODIFIED ||
-+ dtopd(file->f_dentry)->state == CREATED ||
-+ dtopd(file->f_dentry)->state == DEL_REWRITTEN)) {
-+
-+ int tmp = strlen(META_FILENAME);
-+ if(tmp == namlen) {
-+ if(!strncmp(name, META_FILENAME, namlen))
-+ return 0;
-+ }
-+ }
-+
-+ /* check if we are merging the contents of storage and base */
-+ if(file && dtopd(file->f_dentry)->state == MODIFIED) {
-+ /* check if we are still reading storage contents, if
-+ * yes, we just save the name of the file for duplicate
-+ * checking later. */
-+
-+ if(!ftopd(file)->rd.sto_done) {
-+ /* put file into ndl list */
-+ if(ndl_add_entry(&ftopd(file)->rd, name, namlen))
-+ printk(KERN_CRIT "mini_fo_filldir: Error adding to ndl.\n");
-+ } else {
-+ /* check if file has been deleted */
-+ if(meta_check_d_entry(file->f_dentry, name, namlen))
-+ return 0;
-+
-+ /* do duplicate checking */
-+ if(ndl_check_entry(&ftopd(file)->rd, name, namlen))
-+ return 0;
-+ }
-+ }
-+
-+ return mini_fo_filldir_orig(buf, name, namlen, offset, ino, d_type);
-+}
-+
-+
-+STATIC int
-+mini_fo_readdir(file_t *file, void *dirent, filldir_t filldir)
-+{
-+ int err = 0;/* mk: ??? -ENOTDIR; */
-+ file_t *hidden_file = NULL;
-+ file_t *hidden_sto_file = NULL;
-+ inode_t *inode;
-+ struct getdents_callback *buf;
-+ int oldcount;
-+
-+#if defined(FIST_FILTER_NAME) || defined(FIST_FILTER_SCA)
-+ struct mini_fo_getdents_callback buf;
-+#endif /* FIST_FILTER_NAME || FIST_FILTER_SCA */
-+
-+ buf = (struct getdents_callback *) dirent;
-+ oldcount = buf->count;
-+ inode = file->f_dentry->d_inode;
-+ mini_fo_filldir_file = file;
-+ mini_fo_filldir_orig = filldir;
-+
-+ ftopd(file)->rd.sto_done = 0;
-+ do {
-+ if (ftopd(file) != NULL) {
-+ if(ftohf2(file)) {
-+ hidden_sto_file = ftohf2(file);
-+ err = vfs_readdir(hidden_sto_file, mini_fo_filldir, dirent);
-+ file->f_pos = hidden_sto_file->f_pos;
-+ if (err > 0)
-+ fist_copy_attr_atime(inode, hidden_sto_file->f_dentry->d_inode);
-+ /* not finshed yet, we'll be called again */
-+ if (buf->count != oldcount)
-+ break;
-+ }
-+
-+ ftopd(file)->rd.sto_done = 1;
-+
-+ if(ftohf(file)) {
-+ hidden_file = ftohf(file);
-+ err = vfs_readdir(hidden_file, mini_fo_filldir, dirent);
-+ file->f_pos = hidden_file->f_pos;
-+ if (err > 0)
-+ fist_copy_attr_atime(inode, hidden_file->f_dentry->d_inode);
-+ }
-+
-+ }
-+ } while (0);
-+
-+ /* mk:
-+ * we need to check if all the directory data has been copied to userspace,
-+ * or if we will be called again by userspace to complete the operation.
-+ */
-+ if(buf->count == oldcount) {
-+ ndl_put_list(&ftopd(file)->rd);
-+ }
-+
-+ /* unset this, safe */
-+ mini_fo_filldir_file = NULL;
-+ return err;
-+}
-+
-+
-+STATIC unsigned int
-+mini_fo_poll(file_t *file, poll_table *wait)
-+{
-+ unsigned int mask = DEFAULT_POLLMASK;
-+ file_t *hidden_file = NULL;
-+
-+ if (ftopd(file) != NULL) {
-+ if(ftohf2(file)) {
-+ hidden_file = ftohf2(file);
-+ } else {
-+ hidden_file = ftohf(file);
-+ }
-+ }
-+
-+ if (!hidden_file->f_op || !hidden_file->f_op->poll)
-+ goto out;
-+
-+ mask = hidden_file->f_op->poll(hidden_file, wait);
-+
-+ out:
-+ return mask;
-+}
-+
-+/* FIST-LITE special version of mmap */
-+STATIC int
-+mini_fo_mmap(file_t *file, vm_area_t *vma)
-+{
-+ int err = 0;
-+ file_t *hidden_file = NULL;
-+
-+ /* fanout capability */
-+ if (ftopd(file) != NULL) {
-+ if(ftohf2(file)) {
-+ hidden_file = ftohf2(file);
-+ } else {
-+ hidden_file = ftohf(file);
-+ }
-+ }
-+
-+ ASSERT(hidden_file != NULL);
-+ ASSERT(hidden_file->f_op != NULL);
-+ ASSERT(hidden_file->f_op->mmap != NULL);
-+
-+ vma->vm_file = hidden_file;
-+ err = hidden_file->f_op->mmap(hidden_file, vma);
-+ get_file(hidden_file); /* make sure it doesn't get freed on us */
-+ fput(file); /* no need to keep extra ref on ours */
-+
-+ return err;
-+}
-+
-+
-+
-+STATIC int
-+mini_fo_open(inode_t *inode, file_t *file)
-+{
-+ int err = 0;
-+ int hidden_flags;
-+ file_t *hidden_file = NULL;
-+ dentry_t *hidden_dentry = NULL;
-+
-+ /* fanout stuff */
-+ file_t *hidden_sto_file = NULL;
-+ dentry_t *hidden_sto_dentry = NULL;
-+
-+ __ftopd(file) =
-+ kmalloc(sizeof(struct mini_fo_file_info), GFP_KERNEL);
-+ if (!ftopd(file)) {
-+ err = -ENOMEM;
-+ goto out;
-+ }
-+
-+ /* init the readdir_helper structure */
-+ INIT_LIST_HEAD(&ftopd(file)->rd.ndl_list);
-+ ftopd(file)->rd.ndl_size = 0;
-+
-+ /* In certain paths this could stay uninitalized and cause trouble */
-+ ftohf(file) = NULL;
-+ ftohf2(file) = NULL;
-+ hidden_flags = file->f_flags;
-+
-+ /* create storage files? */
-+ if(dtost(file->f_dentry) == UNMODIFIED) {
-+ if(!IS_WRITE_FLAG(file->f_flags)) {
-+ hidden_dentry = dtohd(file->f_dentry);
-+ dget(hidden_dentry);
-+ /* dentry_open will decrement mnt refcnt if err.
-+ * otherwise fput() will do an mntput() for us upon file close. */
-+ mntget(stopd(inode->i_sb)->hidden_mnt);
-+ hidden_file = dentry_open(hidden_dentry,
-+ stopd(inode->i_sb)->hidden_mnt,
-+ hidden_flags);
-+ if (IS_ERR(hidden_file)) {
-+ err = PTR_ERR(hidden_file);
-+ dput(hidden_dentry);
-+ goto out;
-+ }
-+ ftohf(file) = hidden_file; /* link two files */
-+ goto out;
-+ }
-+ else {
-+ if(S_ISDIR(file->f_dentry->d_inode->i_mode)) {
-+ err = dir_unmod_to_mod(file->f_dentry);
-+ } else
-+ err = nondir_unmod_to_mod(file->f_dentry, 1);
-+
-+ if (err) {
-+ printk("mini_fo_open: ERROR creating storage file.\n");
-+ goto out;
-+ }
-+ }
-+ }
-+ hidden_sto_dentry = dtohd2(file->f_dentry);
-+ dget(hidden_sto_dentry);
-+
-+ if(dtopd(file->f_dentry)->state == MODIFIED) {
-+ /* Directorys are special, interpose on both lower level files */
-+ if(S_ISDIR(itohi(inode)->i_mode)) {
-+ /* check for invalid file types of lower level files */
-+ if(!(S_ISDIR(itohi(inode)->i_mode) && S_ISDIR(itohi2(inode)->i_mode))) {
-+ printk(KERN_CRIT "mini_fo_open: meta data corruption detected.\n");
-+ dput(hidden_sto_dentry);
-+ err = -EINVAL;
-+ goto out;
-+ }
-+
-+ /* lower level directorys are ok, open the base file */
-+ hidden_dentry = dtohd(file->f_dentry);
-+ dget(hidden_dentry);
-+
-+ mntget(stopd(inode->i_sb)->hidden_mnt);
-+ hidden_file = dentry_open(hidden_dentry,
-+ stopd(inode->i_sb)->hidden_mnt,
-+ hidden_flags);
-+ if (IS_ERR(hidden_file)) {
-+ err = PTR_ERR(hidden_file);
-+ dput(hidden_dentry);
-+ dput(hidden_sto_dentry);
-+ goto out;
-+ }
-+ ftohf(file) = hidden_file; /* link the two files */
-+ }
-+ }
-+
-+ if(!exists_in_storage(file->f_dentry)) {
-+ printk(KERN_CRIT "mini_fo_open: invalid file state detected.\n");
-+ err = -EINVAL;
-+ dput(hidden_sto_dentry);
-+
-+ /* If the base file has been opened, we need to close it here */
-+ if(ftohf(file)) {
-+ if (hidden_file->f_op && hidden_file->f_op->flush)
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
-+ hidden_file->f_op->flush(hidden_file, NULL);
-+#else
-+ hidden_file->f_op->flush(hidden_file);
-+#endif
-+ dput(hidden_dentry);
-+ }
-+ goto out;
-+ }
-+
-+ /* ok, now we can safely open the storage file */
-+ mntget(stopd(inode->i_sb)->hidden_mnt2);
-+ hidden_sto_file = dentry_open(hidden_sto_dentry,
-+ stopd(inode->i_sb)->hidden_mnt2,
-+ hidden_flags);
-+
-+ /* dentry_open dputs the dentry if it fails */
-+ if (IS_ERR(hidden_sto_file)) {
-+ err = PTR_ERR(hidden_sto_file);
-+ /* close base file if open */
-+ if(ftohf(file)) {
-+ if (hidden_file->f_op && hidden_file->f_op->flush)
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
-+ hidden_file->f_op->flush(hidden_file, NULL);
-+#else
-+ hidden_file->f_op->flush(hidden_file);
-+#endif
-+ dput(hidden_dentry);
-+ }
-+ goto out;
-+ }
-+ ftohf2(file) = hidden_sto_file; /* link storage file */
-+
-+ out:
-+ if (err < 0 && ftopd(file)) {
-+ kfree(ftopd(file));
-+ }
-+ return err;
-+}
-+
-+STATIC int
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
-+mini_fo_flush(file_t *file, fl_owner_t id)
-+#else
-+mini_fo_flush(file_t *file)
-+#endif
-+{
-+ int err1 = 0; /* assume ok (see open.c:close_fp) */
-+ int err2 = 0;
-+ file_t *hidden_file = NULL;
-+
-+ check_mini_fo_file(file);
-+
-+ /* mk: we don't do any state checking here, as its not worth the time.
-+ * Just flush the lower level files if they exist.
-+ */
-+ if(ftopd(file) != NULL) {
-+ if(ftohf(file) != NULL) {
-+ hidden_file = ftohf(file);
-+ if (hidden_file->f_op && hidden_file->f_op->flush)
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
-+ err1 = hidden_file->f_op->flush(hidden_file, id);
-+#else
-+ err1 = hidden_file->f_op->flush(hidden_file);
-+#endif
-+ }
-+ if(ftohf2(file) != NULL) {
-+ hidden_file = ftohf2(file);
-+ if (hidden_file->f_op && hidden_file->f_op->flush)
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
-+ err2 = hidden_file->f_op->flush(hidden_file, id);
-+#else
-+ err2 = hidden_file->f_op->flush(hidden_file);
-+#endif
-+ }
-+ }
-+ return (err1 | err2);
-+}
-+
-+
-+STATIC int
-+mini_fo_release(inode_t *inode, file_t *file)
-+{
-+ int err = 0;
-+ file_t *hidden_file = NULL;
-+
-+ if (ftopd(file) != NULL) {
-+ if(ftohf(file)) {
-+ hidden_file = ftohf(file);
-+ fput(hidden_file);
-+ }
-+ if(ftohf2(file)) {
-+ hidden_file = ftohf2(file);
-+ fput(hidden_file);
-+ }
-+ kfree(ftopd(file));
-+ }
-+ return err;
-+}
-+
-+STATIC int
-+mini_fo_fsync(file_t *file, dentry_t *dentry, int datasync)
-+{
-+ int err1 = 0;
-+ int err2 = 0;
-+ file_t *hidden_file = NULL;
-+ dentry_t *hidden_dentry;
-+
-+ check_mini_fo_file(file);
-+
-+ if ((hidden_file = ftohf(file)) != NULL) {
-+ hidden_dentry = dtohd(dentry);
-+ if (hidden_file->f_op && hidden_file->f_op->fsync) {
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_dentry->d_inode->i_sem);
-+#endif
-+ err1 = hidden_file->f_op->fsync(hidden_file, hidden_dentry, datasync);
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_dentry->d_inode->i_sem);
-+#endif
-+ }
-+ }
-+
-+ if ((hidden_file = ftohf2(file)) != NULL) {
-+ hidden_dentry = dtohd2(dentry);
-+ if (hidden_file->f_op && hidden_file->f_op->fsync) {
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_dentry->d_inode->i_sem);
-+#endif
-+ err2 = hidden_file->f_op->fsync(hidden_file, hidden_dentry, datasync);
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_dentry->d_inode->i_sem);
-+#endif
-+ }
-+ }
-+ else
-+ goto err;
-+
-+err:
-+ return (err1 || err2);
-+}
-+
-+
-+STATIC int
-+mini_fo_fasync(int fd, file_t *file, int flag)
-+{
-+ int err1 = 0;
-+ int err2 = 0;
-+
-+ file_t *hidden_file = NULL;
-+
-+ check_mini_fo_file(file);
-+
-+ if((hidden_file = ftohf(file)) != NULL) {
-+ err1 = hidden_file->f_op->fasync(fd, hidden_file, flag);
-+ }
-+ if((hidden_file = ftohf2(file)) != NULL) {
-+ err2 = hidden_file->f_op->fasync(fd, hidden_file, flag);
-+ }
-+
-+ return (err1 || err2);
-+}
-+
-+
-+
-+struct file_operations mini_fo_dir_fops =
-+ {
-+ read: generic_read_dir,
-+ write: mini_fo_write,
-+ readdir: mini_fo_readdir,
-+ poll: mini_fo_poll,
-+ /* ioctl: mini_fo_ioctl, */
-+ mmap: mini_fo_mmap,
-+ open: mini_fo_open,
-+ flush: mini_fo_flush,
-+ release: mini_fo_release,
-+ fsync: mini_fo_fsync,
-+ fasync: mini_fo_fasync,
-+ /* not needed lock: mini_fo_lock, */
-+ /* not needed: readv */
-+ /* not needed: writev */
-+ /* not implemented: sendpage */
-+ /* not implemented: get_unmapped_area */
-+ };
-+
-+struct file_operations mini_fo_main_fops =
-+ {
-+ llseek: mini_fo_llseek,
-+ read: mini_fo_read,
-+ write: mini_fo_write,
-+ readdir: mini_fo_readdir,
-+ poll: mini_fo_poll,
-+ /* ioctl: mini_fo_ioctl, */
-+ mmap: mini_fo_mmap,
-+ open: mini_fo_open,
-+ flush: mini_fo_flush,
-+ release: mini_fo_release,
-+ fsync: mini_fo_fsync,
-+ fasync: mini_fo_fasync,
-+ /* not needed: lock: mini_fo_lock, */
-+ /* not needed: readv */
-+ /* not needed: writev */
-+ /* not implemented: sendpage */
-+ /* not implemented: get_unmapped_area */
-+ };
---- /dev/null
-+++ b/fs/mini_fo/fist.h
-@@ -0,0 +1,254 @@
-+/*
-+ * Copyright (c) 1997-2003 Erez Zadok
-+ * Copyright (c) 2001-2003 Stony Brook University
-+ *
-+ * For specific licensing information, see the COPYING file distributed with
-+ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
-+ *
-+ * This Copyright notice must be kept intact and distributed with all
-+ * fistgen sources INCLUDING sources generated by fistgen.
-+ */
-+/*
-+ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
-+ *
-+ * This program is free software; you can redistribute it and/or
-+ * modify it under the terms of the GNU General Public License
-+ * as published by the Free Software Foundation; either version
-+ * 2 of the License, or (at your option) any later version.
-+ */
-+
-+
-+/*
-+ * $Id$
-+ */
-+
-+#ifndef __FIST_H_
-+#define __FIST_H_
-+
-+/*
-+ * KERNEL ONLY CODE:
-+ */
-+#ifdef __KERNEL__
-+#include <linux/version.h>
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,33)
-+#include <generated/autoconf.h>
-+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,19)
-+#include <linux/autoconf.h>
-+#else
-+#include <linux/config.h>
-+#endif
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-+#ifdef CONFIG_MODVERSIONS
-+# define MODVERSIONS
-+# include <linux/modversions.h>
-+#endif /* CONFIG_MODVERSIONS */
-+#endif /* KERNEL_VERSION < 2.6.0 */
-+#include <linux/sched.h>
-+#include <linux/kernel.h>
-+#include <linux/mm.h>
-+#include <linux/string.h>
-+#include <linux/stat.h>
-+#include <linux/errno.h>
-+#include <linux/wait.h>
-+#include <linux/limits.h>
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-+#include <linux/locks.h>
-+#else
-+#include <linux/buffer_head.h>
-+#include <linux/pagemap.h>
-+#include <linux/namei.h>
-+#include <linux/module.h>
-+#include <linux/mount.h>
-+#include <linux/page-flags.h>
-+#include <linux/writeback.h>
-+#include <linux/statfs.h>
-+#endif
-+#include <linux/smp.h>
-+#include <linux/smp_lock.h>
-+#include <linux/file.h>
-+#include <linux/slab.h>
-+#include <linux/vmalloc.h>
-+#include <linux/poll.h>
-+#include <linux/list.h>
-+#include <linux/init.h>
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20)
-+#include <linux/xattr.h>
-+#endif
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+#include <linux/security.h>
-+#endif
-+
-+#include <linux/swap.h>
-+
-+#include <asm/system.h>
-+/* #include <asm/segment.h> */
-+#include <asm/mman.h>
-+#include <linux/seq_file.h>
-+
-+/*
-+ * MACROS:
-+ */
-+
-+/* those mapped to ATTR_* were copied from linux/fs.h */
-+#define FA_MODE ATTR_MODE
-+#define FA_UID ATTR_UID
-+#define FA_GID ATTR_GID
-+#define FA_SIZE ATTR_SIZE
-+#define FA_ATIME ATTR_ATIME
-+#define FA_MTIME ATTR_MTIME
-+#define FA_CTIME ATTR_CTIME
-+#define FA_ATIME_SET ATTR_ATIME_SET
-+#define FA_MTIME_SET ATTR_MTIME_SET
-+#define FA_FORCE ATTR_FORCE
-+#define FA_ATTR_FLAGS ATTR_ATTR_FLAG
-+
-+/* must be greater than all other ATTR_* flags! */
-+#define FA_NLINK 2048
-+#define FA_BLKSIZE 4096
-+#define FA_BLOCKS 8192
-+#define FA_TIMES (FA_ATIME|FA_MTIME|FA_CTIME)
-+#define FA_ALL 0
-+
-+/* macros to manage changes between kernels */
-+#define INODE_DATA(i) (&(i)->i_data)
-+
-+#define MIN(x,y) ((x < y) ? (x) : (y))
-+#define MAX(x,y) ((x > y) ? (x) : (y))
-+#define MAXPATHLEN PATH_MAX
-+
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,5)
-+# define lookup_one_len(a,b,c) lookup_one(a,b)
-+#endif /* LINUX_VERSION_CODE < KERNEL_VERSION(2,4,5) */
-+
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,8)
-+# define generic_file_llseek default_llseek
-+#endif /* LINUX_VERSION_CODE < KERNEL_VERSION(2,4,8) */
-+
-+#ifndef SEEK_SET
-+# define SEEK_SET 0
-+#endif /* not SEEK_SET */
-+
-+#ifndef SEEK_CUR
-+# define SEEK_CUR 1
-+#endif /* not SEEK_CUR */
-+
-+#ifndef SEEK_END
-+# define SEEK_END 2
-+#endif /* not SEEK_END */
-+
-+#ifndef DEFAULT_POLLMASK
-+# define DEFAULT_POLLMASK (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)
-+#endif /* not DEFAULT_POLLMASK */
-+
-+/* XXX: fix this so fistgen generates kfree() code directly */
-+#define kfree_s(a,b) kfree(a)
-+
-+/*
-+ * TYPEDEFS:
-+ */
-+typedef struct dentry dentry_t;
-+typedef struct file file_t;
-+typedef struct inode inode_t;
-+typedef inode_t vnode_t;
-+typedef struct page page_t;
-+typedef struct qstr qstr_t;
-+typedef struct super_block super_block_t;
-+typedef super_block_t vfs_t;
-+typedef struct vm_area_struct vm_area_t;
-+
-+
-+/*
-+ * EXTERNALS:
-+ */
-+
-+#define FPPF(str,page) printk("PPF %s 0x%x/%d: Lck:%d Err:%d Ref:%d Upd:%d Other::%d:%d:%d:%d:\n", \
-+ str, \
-+ (int) page, \
-+ (int) page->index, \
-+ (PageLocked(page) ? 1 : 0), \
-+ (PageError(page) ? 1 : 0), \
-+ (PageReferenced(page) ? 1 : 0), \
-+ (Page_Uptodate(page) ? 1 : 0), \
-+ (PageDecrAfter(page) ? 1 : 0), \
-+ (PageSlab(page) ? 1 : 0), \
-+ (PageSwapCache(page) ? 1 : 0), \
-+ (PageReserved(page) ? 1 : 0) \
-+ )
-+#define EZKDBG printk("EZK %s:%d:%s\n",__FILE__,__LINE__,__FUNCTION__)
-+#if 0
-+# define EZKDBG1 printk("EZK %s:%d\n",__FILE__,__LINE__)
-+#else
-+# define EZKDBG1
-+#endif
-+
-+extern int fist_get_debug_value(void);
-+extern int fist_set_debug_value(int val);
-+#if 0 /* mini_fo doesn't need these */
-+extern void fist_dprint_internal(int level, char *str,...);
-+extern void fist_print_dentry(char *str, const dentry_t *dentry);
-+extern void fist_print_inode(char *str, const inode_t *inode);
-+extern void fist_print_file(char *str, const file_t *file);
-+extern void fist_print_buffer_flags(char *str, struct buffer_head *buffer);
-+extern void fist_print_page_flags(char *str, page_t *page);
-+extern void fist_print_page_bytes(char *str, page_t *page);
-+extern void fist_print_pte_flags(char *str, const page_t *page);
-+extern void fist_checkinode(inode_t *inode, char *msg);
-+extern void fist_print_sb(char *str, const super_block_t *sb);
-+
-+/* §$% by mk: special debug functions */
-+extern void fist_mk_print_dentry(char *str, const dentry_t *dentry);
-+extern void fist_mk_print_inode(char *str, const inode_t *inode);
-+
-+extern char *add_indent(void);
-+extern char *del_indent(void);
-+#endif/* mini_fo doesn't need these */
-+
-+
-+#define STATIC
-+#define ASSERT(EX) \
-+do { \
-+ if (!(EX)) { \
-+ printk(KERN_CRIT "ASSERTION FAILED: %s at %s:%d (%s)\n", #EX, \
-+ __FILE__, __LINE__, __FUNCTION__); \
-+ (*((char *)0))=0; \
-+ } \
-+} while (0)
-+/* same ASSERT, but tell me who was the caller of the function */
-+#define ASSERT2(EX) \
-+do { \
-+ if (!(EX)) { \
-+ printk(KERN_CRIT "ASSERTION FAILED (caller): %s at %s:%d (%s)\n", #EX, \
-+ file, line, func); \
-+ (*((char *)0))=0; \
-+ } \
-+} while (0)
-+
-+#if 0 /* mini_fo doesn't need these */
-+#define dprintk(format, args...) printk(KERN_DEBUG format, ##args)
-+#define fist_dprint(level, str, args...) fist_dprint_internal(level, KERN_DEBUG str, ## args)
-+#define print_entry_location() fist_dprint(4, "%sIN: %s %s:%d\n", add_indent(), __FUNCTION__, __FILE__, __LINE__)
-+#define print_exit_location() fist_dprint(4, "%s OUT: %s %s:%d\n", del_indent(), __FUNCTION__, __FILE__, __LINE__)
-+#define print_exit_status(status) fist_dprint(4, "%s OUT: %s %s:%d, STATUS: %d\n", del_indent(), __FUNCTION__, __FILE__, __LINE__, status)
-+#define print_exit_pointer(status) \
-+do { \
-+ if (IS_ERR(status)) \
-+ fist_dprint(4, "%s OUT: %s %s:%d, RESULT: %ld\n", del_indent(), __FUNCTION__, __FILE__, __LINE__, PTR_ERR(status)); \
-+ else \
-+ fist_dprint(4, "%s OUT: %s %s:%d, RESULT: 0x%x\n", del_indent(), __FUNCTION__, __FILE__, __LINE__, PTR_ERR(status)); \
-+} while (0)
-+#endif/* mini_fo doesn't need these */
-+
-+#endif /* __KERNEL__ */
-+
-+
-+/*
-+ * DEFINITIONS FOR USER AND KERNEL CODE:
-+ * (Note: ioctl numbers 1--9 are reserved for fistgen, the rest
-+ * are auto-generated automatically based on the user's .fist file.)
-+ */
-+# define FIST_IOCTL_GET_DEBUG_VALUE _IOR(0x15, 1, int)
-+# define FIST_IOCTL_SET_DEBUG_VALUE _IOW(0x15, 2, int)
-+
-+#endif /* not __FIST_H_ */
---- /dev/null
-+++ b/fs/mini_fo/inode.c
-@@ -0,0 +1,1564 @@
-+/*
-+ * Copyright (c) 1997-2003 Erez Zadok
-+ * Copyright (c) 2001-2003 Stony Brook University
-+ *
-+ * For specific licensing information, see the COPYING file distributed with
-+ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
-+ *
-+ * This Copyright notice must be kept intact and distributed with all
-+ * fistgen sources INCLUDING sources generated by fistgen.
-+ */
-+/*
-+ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
-+ *
-+ * This program is free software; you can redistribute it and/or
-+ * modify it under the terms of the GNU General Public License
-+ * as published by the Free Software Foundation; either version
-+ * 2 of the License, or (at your option) any later version.
-+ */
-+
-+/*
-+ * $Id$
-+ */
-+
-+#ifdef HAVE_CONFIG_H
-+# include <config.h>
-+#endif
-+
-+#include "fist.h"
-+#include "mini_fo.h"
-+
-+STATIC int
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+mini_fo_create(inode_t *dir, dentry_t *dentry, int mode, struct nameidata *nd)
-+#else
-+mini_fo_create(inode_t *dir, dentry_t *dentry, int mode)
-+#endif
-+{
-+ int err = 0;
-+
-+ check_mini_fo_dentry(dentry);
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ err = create_sto_reg_file(dentry, mode, nd);
-+#else
-+ err = create_sto_reg_file(dentry, mode);
-+#endif
-+ check_mini_fo_dentry(dentry);
-+ return err;
-+}
-+
-+
-+STATIC dentry_t *
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+mini_fo_lookup(inode_t *dir, dentry_t *dentry, struct nameidata* nd)
-+#else
-+mini_fo_lookup(inode_t *dir, dentry_t *dentry)
-+#endif
-+{
-+ int err = 0;
-+ dentry_t *hidden_dir_dentry;
-+ dentry_t *hidden_dentry = NULL;
-+
-+ dentry_t *hidden_sto_dir_dentry;
-+ dentry_t *hidden_sto_dentry = NULL;
-+
-+ /* whiteout flag */
-+ int del_flag = 0;
-+ char *bpath = NULL;
-+
-+ const char *name;
-+ unsigned int namelen;
-+
-+ /* Don't allow lookups of META-files */
-+ namelen = strlen(META_FILENAME);
-+ if(namelen == dentry->d_name.len) {
-+ if(!strncmp(dentry->d_name.name, META_FILENAME, namelen)) {
-+ err = -ENOENT;
-+ goto out;
-+ }
-+ }
-+
-+ hidden_dir_dentry = dtohd(dentry->d_parent);
-+ hidden_sto_dir_dentry = dtohd2(dentry->d_parent);
-+
-+ name = dentry->d_name.name;
-+ namelen = dentry->d_name.len;
-+
-+ /* must initialize dentry operations */
-+ dentry->d_op = &mini_fo_dops;
-+
-+ /* setup the del_flag */
-+ del_flag = __meta_check_d_entry(dir, name, namelen);
-+ bpath = __meta_check_r_entry(dir, name, namelen);
-+
-+ /* perform the lookups of base and storage files:
-+ *
-+ * This caused some serious trouble, as a lookup_one_len passing
-+ * a negative dentry oopses. Solution is to only do the lookup
-+ * if the dentry is positive, else we set it to NULL
-+ * More trouble, who said a *_dir_dentry can't be NULL?
-+ */
-+ if(bpath) {
-+ /* Cross-Interposing (C), yeah! */
-+ hidden_dentry = bpath_walk(dir->i_sb, bpath);
-+ if(!hidden_dentry || !hidden_dentry->d_inode) {
-+ printk(KERN_CRIT "mini_fo_lookup: bpath_walk failed.\n");
-+ err= -EINVAL;
-+ goto out;
-+ }
-+
-+ /* this can be set up safely without fear of spaghetti
-+ * interposing as it is only used for copying times */
-+ hidden_dir_dentry = hidden_dentry->d_parent;
-+ kfree(bpath);
-+ }
-+ else if(hidden_dir_dentry && hidden_dir_dentry->d_inode)
-+ hidden_dentry =
-+ lookup_one_len(name, hidden_dir_dentry, namelen);
-+ else
-+ hidden_dentry = NULL;
-+
-+ if(hidden_sto_dir_dentry && hidden_sto_dir_dentry->d_inode)
-+ hidden_sto_dentry =
-+ lookup_one_len(name, hidden_sto_dir_dentry, namelen);
-+ else
-+ hidden_sto_dentry = NULL;
-+
-+ /* catch error in lookup */
-+ if (IS_ERR(hidden_dentry) || IS_ERR(hidden_sto_dentry)) {
-+ /* mk: we need to call dput on the dentry, whose
-+ * lookup_one_len operation failed, in order to avoid
-+ * unmount trouble.
-+ */
-+ if(IS_ERR(hidden_dentry)) {
-+ printk(KERN_CRIT "mini_fo_lookup: ERR from base dentry, lookup failed.\n");
-+ err = PTR_ERR(hidden_dentry);
-+ } else {
-+ dput(hidden_dentry);
-+ }
-+ if(IS_ERR(hidden_sto_dentry)) {
-+ printk(KERN_CRIT "mini_fo_lookup: ERR from storage dentry, lookup failed.\n");
-+ err = PTR_ERR(hidden_sto_dentry);
-+ } else {
-+ dput(hidden_sto_dentry);
-+ }
-+ goto out;
-+ }
-+
-+ /* allocate dentry private data */
-+ __dtopd(dentry) = (struct mini_fo_dentry_info *)
-+ kmalloc(sizeof(struct mini_fo_dentry_info), GFP_KERNEL);
-+
-+ if (!dtopd(dentry)) {
-+ err = -ENOMEM;
-+ goto out_dput;
-+ }
-+
-+ /* check for different states of the mini_fo file to be looked up. */
-+
-+ /* state 1, file has been modified */
-+ if(hidden_dentry && hidden_sto_dentry &&
-+ hidden_dentry->d_inode && hidden_sto_dentry->d_inode && !del_flag) {
-+
-+ /* update parent directory's atime */
-+ fist_copy_attr_atime(dir, hidden_sto_dir_dentry->d_inode);
-+
-+ dtopd(dentry)->state = MODIFIED;
-+ dtohd(dentry) = hidden_dentry;
-+ dtohd2(dentry) = hidden_sto_dentry;
-+
-+ err = mini_fo_tri_interpose(hidden_dentry,
-+ hidden_sto_dentry,
-+ dentry, dir->i_sb, 1);
-+ if (err) {
-+ printk(KERN_CRIT "mini_fo_lookup: error interposing (state1).\n");
-+ goto out_free;
-+ }
-+ goto out;
-+ }
-+ /* state 2, file is unmodified */
-+ if(hidden_dentry && hidden_dentry->d_inode && !del_flag) {
-+
-+ fist_copy_attr_atime(dir, hidden_dir_dentry->d_inode);
-+
-+ dtopd(dentry)->state = UNMODIFIED;
-+ dtohd(dentry) = hidden_dentry;
-+ dtohd2(dentry) = hidden_sto_dentry; /* could be negative */
-+
-+ err = mini_fo_tri_interpose(hidden_dentry,
-+ hidden_sto_dentry,
-+ dentry, dir->i_sb, 1);
-+ if (err) {
-+ printk(KERN_CRIT "mini_fo_lookup: error interposing (state2).\n");
-+ goto out_free;
-+ }
-+ goto out;
-+ }
-+ /* state 3, file has been newly created */
-+ if(hidden_sto_dentry && hidden_sto_dentry->d_inode && !del_flag) {
-+
-+ fist_copy_attr_atime(dir, hidden_sto_dir_dentry->d_inode);
-+ dtopd(dentry)->state = CREATED;
-+ dtohd(dentry) = hidden_dentry; /* could be negative */
-+ dtohd2(dentry) = hidden_sto_dentry;
-+
-+ err = mini_fo_tri_interpose(hidden_dentry,
-+ hidden_sto_dentry,
-+ dentry, dir->i_sb, 1);
-+ if (err) {
-+ printk(KERN_CRIT "mini_fo_lookup: error interposing (state3).\n");
-+ goto out_free;
-+ }
-+ goto out;
-+ }
-+
-+ /* state 4, file has deleted and created again. */
-+ if(hidden_dentry && hidden_sto_dentry &&
-+ hidden_dentry->d_inode &&
-+ hidden_sto_dentry->d_inode && del_flag) {
-+
-+ fist_copy_attr_atime(dir, hidden_sto_dir_dentry->d_inode);
-+ dtopd(dentry)->state = DEL_REWRITTEN;
-+ dtohd(dentry) = NULL;
-+ dtohd2(dentry) = hidden_sto_dentry;
-+
-+ err = mini_fo_tri_interpose(NULL,
-+ hidden_sto_dentry,
-+ dentry, dir->i_sb, 1);
-+ if (err) {
-+ printk(KERN_CRIT "mini_fo_lookup: error interposing (state4).\n");
-+ goto out_free;
-+ }
-+ /* We will never need this dentry again, as the file has been
-+ * deleted from base */
-+ dput(hidden_dentry);
-+ goto out;
-+ }
-+ /* state 5, file has been deleted in base */
-+ if(hidden_dentry && hidden_sto_dentry &&
-+ hidden_dentry->d_inode &&
-+ !hidden_sto_dentry->d_inode && del_flag) {
-+
-+ /* check which parents atime we need for updating */
-+ if(hidden_sto_dir_dentry->d_inode)
-+ fist_copy_attr_atime(dir,
-+ hidden_sto_dir_dentry->d_inode);
-+ else
-+ fist_copy_attr_atime(dir,
-+ hidden_dir_dentry->d_inode);
-+
-+ dtopd(dentry)->state = DELETED;
-+ dtohd(dentry) = NULL;
-+ dtohd2(dentry) = hidden_sto_dentry;
-+
-+ /* add negative dentry to dcache to speed up lookups */
-+ d_add(dentry, NULL);
-+ dput(hidden_dentry);
-+ goto out;
-+ }
-+ /* state 6, file does not exist */
-+ if(((hidden_dentry && !hidden_dentry->d_inode) ||
-+ (hidden_sto_dentry && !hidden_sto_dentry->d_inode)) && !del_flag)
-+ {
-+ /* check which parents atime we need for updating */
-+ if(hidden_sto_dir_dentry && hidden_sto_dir_dentry->d_inode)
-+ fist_copy_attr_atime(dir, hidden_sto_dir_dentry->d_inode);
-+ else
-+ fist_copy_attr_atime(dir, hidden_dir_dentry->d_inode);
-+
-+ dtopd(dentry)->state = NON_EXISTANT;
-+ dtohd(dentry) = hidden_dentry;
-+ dtohd2(dentry) = hidden_sto_dentry;
-+ d_add(dentry, NULL);
-+ goto out;
-+ }
-+
-+ /* if we get to here, were in an invalid state. bad. */
-+ printk(KERN_CRIT "mini_fo_lookup: ERROR, meta data corruption detected.\n");
-+
-+ /* end state checking */
-+ out_free:
-+ d_drop(dentry); /* so that our bad dentry will get destroyed */
-+ kfree(dtopd(dentry));
-+ __dtopd(dentry) = NULL; /* be safe */
-+
-+ out_dput:
-+ if(hidden_dentry)
-+ dput(hidden_dentry);
-+ if(hidden_sto_dentry)
-+ dput(hidden_sto_dentry); /* drops usage count and marks for release */
-+
-+ out:
-+ /* initalize wol if file exists and is directory */
-+ if(dentry->d_inode) {
-+ if(S_ISDIR(dentry->d_inode->i_mode)) {
-+ itopd(dentry->d_inode)->deleted_list_size = -1;
-+ itopd(dentry->d_inode)->renamed_list_size = -1;
-+ meta_build_lists(dentry);
-+ }
-+ }
-+ return ERR_PTR(err);
-+}
-+
-+
-+STATIC int
-+mini_fo_link(dentry_t *old_dentry, inode_t *dir, dentry_t *new_dentry)
-+{
-+ int err;
-+ dentry_t *hidden_old_dentry;
-+ dentry_t *hidden_new_dentry;
-+ dentry_t *hidden_dir_dentry;
-+
-+
-+ check_mini_fo_dentry(old_dentry);
-+ check_mini_fo_dentry(new_dentry);
-+ check_mini_fo_inode(dir);
-+
-+ /* no links to directorys and existing targets target allowed */
-+ if(S_ISDIR(old_dentry->d_inode->i_mode) ||
-+ is_mini_fo_existant(new_dentry)) {
-+ err = -EPERM;
-+ goto out;
-+ }
-+
-+ /* bring it directly from unmod to del_rew */
-+ if(dtost(old_dentry) == UNMODIFIED) {
-+ err = nondir_unmod_to_mod(old_dentry, 1);
-+ if(err) {
-+ err = -EINVAL;
-+ goto out;
-+ }
-+ err = meta_add_d_entry(old_dentry->d_parent,
-+ old_dentry->d_name.name,
-+ old_dentry->d_name.len);
-+ if(err) {
-+ err = -EINVAL;
-+ goto out;
-+ }
-+ dput(dtohd(old_dentry));
-+ dtohd(old_dentry) = NULL;
-+ dtost(old_dentry) = DEL_REWRITTEN;
-+ }
-+
-+ err = get_neg_sto_dentry(new_dentry);
-+ if(err) {
-+ err = -EINVAL;
-+ goto out;
-+ }
-+
-+ hidden_old_dentry = dtohd2(old_dentry);
-+ hidden_new_dentry = dtohd2(new_dentry);
-+
-+ dget(hidden_old_dentry);
-+ dget(hidden_new_dentry);
-+
-+ /* was: hidden_dir_dentry = lock_parent(hidden_new_dentry); */
-+ hidden_dir_dentry = dget(hidden_new_dentry->d_parent);
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_dir_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_dir_dentry->d_inode->i_sem);
-+#endif
-+
-+ err = vfs_link(hidden_old_dentry,
-+ hidden_dir_dentry->d_inode,
-+ hidden_new_dentry);
-+ if (err || !hidden_new_dentry->d_inode)
-+ goto out_lock;
-+
-+ dtost(new_dentry) = CREATED;
-+ err = mini_fo_tri_interpose(NULL, hidden_new_dentry, new_dentry, dir->i_sb, 0);
-+ if (err)
-+ goto out_lock;
-+
-+ fist_copy_attr_timesizes(dir, hidden_new_dentry->d_inode);
-+ /* propagate number of hard-links */
-+ old_dentry->d_inode->i_nlink = itohi2(old_dentry->d_inode)->i_nlink;
-+
-+ out_lock:
-+ /* was: unlock_dir(hidden_dir_dentry); */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_dir_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_dir_dentry->d_inode->i_sem);
-+#endif
-+ dput(hidden_dir_dentry);
-+
-+ dput(hidden_new_dentry);
-+ dput(hidden_old_dentry);
-+ if (!new_dentry->d_inode)
-+ d_drop(new_dentry);
-+
-+ out:
-+ return err;
-+}
-+
-+
-+STATIC int
-+mini_fo_unlink(inode_t *dir, dentry_t *dentry)
-+{
-+ int err = 0;
-+
-+ dget(dentry);
-+ if(dtopd(dentry)->state == MODIFIED) {
-+ err = nondir_mod_to_del(dentry);
-+ goto out;
-+ }
-+ else if(dtopd(dentry)->state == UNMODIFIED) {
-+ err = nondir_unmod_to_del(dentry);
-+ goto out;
-+ }
-+ else if(dtopd(dentry)->state == CREATED) {
-+ err = nondir_creat_to_del(dentry);
-+ goto out;
-+ }
-+ else if(dtopd(dentry)->state == DEL_REWRITTEN) {
-+ err = nondir_del_rew_to_del(dentry);
-+ goto out;
-+ }
-+
-+ printk(KERN_CRIT "mini_fo_unlink: ERROR, invalid state detected.\n");
-+
-+ out:
-+ fist_copy_attr_times(dir, itohi2(dentry->d_parent->d_inode));
-+
-+ if(!err) {
-+ /* is this causing my pain? d_delete(dentry); */
-+ d_drop(dentry);
-+ }
-+
-+ dput(dentry);
-+ return err;
-+}
-+
-+
-+STATIC int
-+mini_fo_symlink(inode_t *dir, dentry_t *dentry, const char *symname)
-+{
-+ int err=0;
-+ dentry_t *hidden_sto_dentry;
-+ dentry_t *hidden_sto_dir_dentry;
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ umode_t mode;
-+#endif
-+
-+ /* Fail if the symlink file exists */
-+ if(!(dtost(dentry) == DELETED ||
-+ dtost(dentry) == NON_EXISTANT)) {
-+ err = -EEXIST;
-+ goto out;
-+ }
-+
-+ err = get_neg_sto_dentry(dentry);
-+ if(err) {
-+ err = -EINVAL;
-+ goto out;
-+ }
-+ hidden_sto_dentry = dtohd2(dentry);
-+
-+ dget(hidden_sto_dentry);
-+ /* was: hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry); */
-+ hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ mode = S_IALLUGO;
-+ err = vfs_symlink(hidden_sto_dir_dentry->d_inode,
-+ hidden_sto_dentry, symname, mode);
-+#else
-+ err = vfs_symlink(hidden_sto_dir_dentry->d_inode,
-+ hidden_sto_dentry,
-+ symname);
-+#endif
-+ if (err || !hidden_sto_dentry->d_inode)
-+ goto out_lock;
-+
-+ if(dtost(dentry) == DELETED) {
-+ dtost(dentry) = DEL_REWRITTEN;
-+ err = mini_fo_tri_interpose(NULL, hidden_sto_dentry, dentry, dir->i_sb, 0);
-+ if(err)
-+ goto out_lock;
-+ } else if(dtost(dentry) == NON_EXISTANT) {
-+ dtost(dentry) = CREATED;
-+ err = mini_fo_tri_interpose(dtohd(dentry), hidden_sto_dentry, dentry, dir->i_sb, 0);
-+ if(err)
-+ goto out_lock;
-+ }
-+ fist_copy_attr_timesizes(dir, hidden_sto_dir_dentry->d_inode);
-+
-+ out_lock:
-+ /* was: unlock_dir(hidden_sto_dir_dentry); */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+ dput(hidden_sto_dir_dentry);
-+
-+ dput(hidden_sto_dentry);
-+ if (!dentry->d_inode)
-+ d_drop(dentry);
-+ out:
-+ return err;
-+}
-+
-+STATIC int
-+mini_fo_mkdir(inode_t *dir, dentry_t *dentry, int mode)
-+{
-+ int err;
-+
-+ err = create_sto_dir(dentry, mode);
-+
-+ check_mini_fo_dentry(dentry);
-+
-+ return err;
-+}
-+
-+
-+STATIC int
-+mini_fo_rmdir(inode_t *dir, dentry_t *dentry)
-+{
-+ int err = 0;
-+
-+ dentry_t *hidden_sto_dentry;
-+ dentry_t *hidden_sto_dir_dentry;
-+ dentry_t *meta_dentry;
-+ inode_t *hidden_sto_dir = NULL;
-+
-+ check_mini_fo_dentry(dentry);
-+ check_mini_fo_inode(dir);
-+
-+ dget(dentry);
-+ if(dtopd(dentry)->state == MODIFIED) {
-+ /* XXX: disabled, because it does not bother to check files on
-+ * the original filesystem - just a hack, but better than simply
-+ * removing it without testing */
-+ err = -EINVAL;
-+ goto out;
-+
-+ hidden_sto_dir = itohi2(dir);
-+ hidden_sto_dentry = dtohd2(dentry);
-+
-+ /* was:hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry); */
-+ hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+
-+ /* Delete an old WOL file contained in the storage dir */
-+ meta_dentry = lookup_one_len(META_FILENAME,
-+ hidden_sto_dentry,
-+ strlen(META_FILENAME));
-+ if(meta_dentry->d_inode) {
-+ err = vfs_unlink(hidden_sto_dentry->d_inode, meta_dentry);
-+ dput(meta_dentry);
-+ if(!err)
-+ d_delete(meta_dentry);
-+ }
-+
-+ err = vfs_rmdir(hidden_sto_dir, hidden_sto_dentry);
-+ dput(hidden_sto_dentry);
-+ if(!err)
-+ d_delete(hidden_sto_dentry);
-+
-+ /* propagate number of hard-links */
-+ dentry->d_inode->i_nlink = itohi2(dentry->d_inode)->i_nlink;
-+
-+ dput(dtohd(dentry));
-+
-+ dtohd(dentry) = NULL;
-+ dtopd(dentry)->state = DELETED;
-+
-+ /* carefull with R files */
-+ if( __meta_is_r_entry(dir,
-+ dentry->d_name.name,
-+ dentry->d_name.len) == 1) {
-+ err = meta_remove_r_entry(dentry->d_parent,
-+ dentry->d_name.name,
-+ dentry->d_name.len);
-+ if(err) {
-+ printk(KERN_CRIT "mini_fo: rmdir: meta_remove_r_entry failed.\n");
-+ goto out;
-+ }
-+ }
-+ else {
-+ /* ok, add deleted file to META */
-+ meta_add_d_entry(dentry->d_parent,
-+ dentry->d_name.name,
-+ dentry->d_name.len);
-+ }
-+ /* was: unlock_dir(hidden_sto_dir_dentry); */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+ dput(hidden_sto_dir_dentry);
-+ goto out;
-+ }
-+ else if(dtopd(dentry)->state == UNMODIFIED) {
-+ /* XXX: simply adding it to the delete list here is fscking dangerous!
-+ * as a temporary hack, i will disable rmdir on unmodified directories
-+ * for now.
-+ */
-+ err = -EINVAL;
-+ goto out;
-+
-+ err = get_neg_sto_dentry(dentry);
-+ if(err) {
-+ err = -EINVAL;
-+ goto out;
-+ }
-+
-+ /* dput base dentry, this will relase the inode and free the
-+ * dentry, as we will never need it again. */
-+ dput(dtohd(dentry));
-+ dtohd(dentry) = NULL;
-+ dtopd(dentry)->state = DELETED;
-+
-+ /* add deleted file to META-file */
-+ meta_add_d_entry(dentry->d_parent,
-+ dentry->d_name.name,
-+ dentry->d_name.len);
-+ goto out;
-+ }
-+ else if(dtopd(dentry)->state == CREATED) {
-+ hidden_sto_dir = itohi2(dir);
-+ hidden_sto_dentry = dtohd2(dentry);
-+
-+ /* was: hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry);*/
-+ hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+
-+ /* Delete an old WOL file contained in the storage dir */
-+ meta_dentry = lookup_one_len(META_FILENAME,
-+ hidden_sto_dentry,
-+ strlen(META_FILENAME));
-+ if(meta_dentry->d_inode) {
-+ /* is this necessary? dget(meta_dentry); */
-+ err = vfs_unlink(hidden_sto_dentry->d_inode,
-+ meta_dentry);
-+ dput(meta_dentry);
-+ if(!err)
-+ d_delete(meta_dentry);
-+ }
-+
-+ err = vfs_rmdir(hidden_sto_dir, hidden_sto_dentry);
-+ dput(hidden_sto_dentry);
-+ if(!err)
-+ d_delete(hidden_sto_dentry);
-+
-+ /* propagate number of hard-links */
-+ dentry->d_inode->i_nlink = itohi2(dentry->d_inode)->i_nlink;
-+ dtopd(dentry)->state = NON_EXISTANT;
-+
-+ /* was: unlock_dir(hidden_sto_dir_dentry); */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+ dput(hidden_sto_dir_dentry);
-+
-+ goto out;
-+ }
-+ else if(dtopd(dentry)->state == DEL_REWRITTEN) {
-+ hidden_sto_dir = itohi2(dir);
-+ hidden_sto_dentry = dtohd2(dentry);
-+
-+ /* was: hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry);*/
-+ hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+
-+ /* Delete an old WOL file contained in the storage dir */
-+ meta_dentry = lookup_one_len(META_FILENAME,
-+ hidden_sto_dentry,
-+ strlen(META_FILENAME));
-+ if(meta_dentry->d_inode) {
-+ /* is this necessary? dget(meta_dentry); */
-+ err = vfs_unlink(hidden_sto_dentry->d_inode,
-+ meta_dentry);
-+ dput(meta_dentry);
-+ if(!err)
-+ d_delete(meta_dentry);
-+ }
-+
-+ err = vfs_rmdir(hidden_sto_dir, hidden_sto_dentry);
-+ dput(hidden_sto_dentry);
-+ if(!err)
-+ d_delete(hidden_sto_dentry);
-+
-+ /* propagate number of hard-links */
-+ dentry->d_inode->i_nlink = itohi2(dentry->d_inode)->i_nlink;
-+ dtopd(dentry)->state = DELETED;
-+ /* was: unlock_dir(hidden_sto_dir_dentry); */
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+ dput(hidden_sto_dir_dentry);
-+ goto out;
-+ }
-+
-+ printk(KERN_CRIT "mini_fo_rmdir: ERROR, invalid state detected.\n");
-+
-+ out:
-+ if(!err) {
-+ d_drop(dentry);
-+ }
-+
-+ fist_copy_attr_times(dir, itohi2(dentry->d_parent->d_inode));
-+ dput(dentry);
-+
-+ return err;
-+}
-+
-+
-+STATIC int
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+mini_fo_mknod(inode_t *dir, dentry_t *dentry, int mode, dev_t dev)
-+#else
-+mini_fo_mknod(inode_t *dir, dentry_t *dentry, int mode, int dev)
-+#endif
-+{
-+ int err = 0;
-+
-+ check_mini_fo_dentry(dentry);
-+
-+ err = create_sto_nod(dentry, mode, dev);
-+ if(err) {
-+ printk(KERN_CRIT "mini_fo_mknod: creating sto nod failed.\n");
-+ err = -EINVAL;
-+ }
-+
-+ check_mini_fo_dentry(dentry);
-+ return err;
-+}
-+
-+
-+STATIC int
-+mini_fo_rename(inode_t *old_dir, dentry_t *old_dentry,
-+ inode_t *new_dir, dentry_t *new_dentry)
-+{
-+ /* dispatch */
-+ if(S_ISDIR(old_dentry->d_inode->i_mode))
-+ return rename_directory(old_dir, old_dentry, new_dir, new_dentry);
-+ return rename_nondir(old_dir, old_dentry, new_dir, new_dentry);
-+
-+}
-+
-+int rename_directory(inode_t *old_dir, dentry_t *old_dentry,
-+ inode_t *new_dir, dentry_t *new_dentry)
-+{
-+ int err, bpath_len;
-+ char *bpath;
-+
-+ dentry_t *hidden_old_dentry;
-+ dentry_t *hidden_new_dentry;
-+ dentry_t *hidden_old_dir_dentry;
-+ dentry_t *hidden_new_dir_dentry;
-+
-+ err = 0;
-+ bpath = NULL;
-+ bpath_len = 0;
-+
-+ /* this is a test, chuck out if it works */
-+ if(!(dtopd(new_dentry)->state == DELETED ||
-+ dtopd(new_dentry)->state == NON_EXISTANT)) {
-+ printk(KERN_CRIT "mini_fo: rename_directory: \
-+ uh, ah, new_dentry not negative.\n");
-+ /* return -1; */
-+ }
-+
-+ /* state = UNMODIFIED */
-+ if(dtopd(old_dentry)->state == UNMODIFIED) {
-+ err = dir_unmod_to_mod(old_dentry);
-+ if (err)
-+ goto out;
-+ }
-+
-+ /* state = MODIFIED */
-+ if(dtopd(old_dentry)->state == MODIFIED) {
-+ bpath = meta_check_r_entry(old_dentry->d_parent,
-+ old_dentry->d_name.name,
-+ old_dentry->d_name.len);
-+ if(bpath) {
-+ err = meta_remove_r_entry(old_dentry->d_parent,
-+ old_dentry->d_name.name,
-+ old_dentry->d_name.len);
-+ if(err) {
-+ printk(KERN_CRIT "mini_fo: rename_directory:\
-+ meta_remove_r_entry \
-+ failed.\n");
-+ goto out;
-+ }
-+ err = meta_add_r_entry(new_dentry->d_parent,
-+ bpath,
-+ strlen(bpath),
-+ new_dentry->d_name.name,
-+ new_dentry->d_name.len);
-+ kfree(bpath);
-+ }
-+ else {/* wol it */
-+ err = meta_add_d_entry(old_dentry->d_parent,
-+ old_dentry->d_name.name,
-+ old_dentry->d_name.len);
-+ if (err)
-+ goto out;
-+ /* put it on rename list */
-+ err = get_mini_fo_bpath(old_dentry,
-+ &bpath,
-+ &bpath_len);
-+ if (err)
-+ goto out;
-+ err = meta_add_r_entry(new_dentry->d_parent,
-+ bpath, bpath_len,
-+ new_dentry->d_name.name,
-+ new_dentry->d_name.len);
-+ if (err)
-+ goto out;
-+ }
-+ /* no state change, MODIFIED stays MODIFIED */
-+ }
-+ /* state = CREATED */
-+ if(dtopd(old_dentry)->state == CREATED ||
-+ dtopd(old_dentry)->state == DEL_REWRITTEN) {
-+ if(dtohd(old_dentry))
-+ dput(dtohd(old_dentry));
-+
-+ if(dtopd(new_dentry)->state == DELETED) {
-+ dtopd(old_dentry)->state = DEL_REWRITTEN;
-+ dtohd(old_dentry) = NULL;
-+ }
-+ else if(dtopd(new_dentry)->state == NON_EXISTANT) {
-+ dtopd(old_dentry)->state = CREATED;
-+ /* steal new dentry's neg. base dentry */
-+ dtohd(old_dentry) = dtohd(new_dentry);
-+ dtohd(new_dentry) = NULL;
-+ }
-+ }
-+ if(dtopd(new_dentry)->state == UNMODIFIED ||
-+ dtopd(new_dentry)->state == NON_EXISTANT) {
-+ err = get_neg_sto_dentry(new_dentry);
-+ if(err)
-+ goto out;
-+ }
-+
-+ /* now move sto file */
-+ hidden_old_dentry = dtohd2(old_dentry);
-+ hidden_new_dentry = dtohd2(new_dentry);
-+
-+ dget(hidden_old_dentry);
-+ dget(hidden_new_dentry);
-+
-+ hidden_old_dir_dentry = dget(hidden_old_dentry->d_parent);
-+ hidden_new_dir_dentry = dget(hidden_new_dentry->d_parent);
-+ double_lock(hidden_old_dir_dentry, hidden_new_dir_dentry);
-+
-+ err = vfs_rename(hidden_old_dir_dentry->d_inode, hidden_old_dentry,
-+ hidden_new_dir_dentry->d_inode, hidden_new_dentry);
-+ if(err)
-+ goto out_lock;
-+
-+ fist_copy_attr_all(new_dir, hidden_new_dir_dentry->d_inode);
-+ if (new_dir != old_dir)
-+ fist_copy_attr_all(old_dir,
-+ hidden_old_dir_dentry->d_inode);
-+
-+ out_lock:
-+ /* double_unlock will dput the new/old parent dentries
-+ * whose refcnts were incremented via get_parent above. */
-+ double_unlock(hidden_old_dir_dentry, hidden_new_dir_dentry);
-+ dput(hidden_new_dentry);
-+ dput(hidden_old_dentry);
-+
-+ out:
-+ return err;
-+}
-+
-+int rename_nondir(inode_t *old_dir, dentry_t *old_dentry,
-+ inode_t *new_dir, dentry_t *new_dentry)
-+{
-+ int err=0;
-+
-+ check_mini_fo_dentry(old_dentry);
-+ check_mini_fo_dentry(new_dentry);
-+ check_mini_fo_inode(old_dir);
-+ check_mini_fo_inode(new_dir);
-+
-+ /* state: UNMODIFIED */
-+ if(dtost(old_dentry) == UNMODIFIED) {
-+ err = nondir_unmod_to_mod(old_dentry, 1);
-+ if(err) {
-+ err = -EINVAL;
-+ goto out;
-+ }
-+ }
-+
-+ /* the easy states */
-+ if(exists_in_storage(old_dentry)) {
-+
-+ dentry_t *hidden_old_dentry;
-+ dentry_t *hidden_new_dentry;
-+ dentry_t *hidden_old_dir_dentry;
-+ dentry_t *hidden_new_dir_dentry;
-+
-+ /* if old file is MODIFIED, add it to the deleted_list */
-+ if(dtopd(old_dentry)->state == MODIFIED) {
-+ meta_add_d_entry(old_dentry->d_parent,
-+ old_dentry->d_name.name,
-+ old_dentry->d_name.len);
-+
-+ dput(dtohd(old_dentry));
-+ }
-+ /* if old file is CREATED, we only release the base dentry */
-+ if(dtopd(old_dentry)->state == CREATED) {
-+ if(dtohd(old_dentry))
-+ dput(dtohd(old_dentry));
-+ }
-+
-+ /* now setup the new states (depends on new_dentry state) */
-+ /* new dentry state = MODIFIED */
-+ if(dtopd(new_dentry)->state == MODIFIED) {
-+ meta_add_d_entry(new_dentry->d_parent,
-+ new_dentry->d_name.name,
-+ new_dentry->d_name.len);
-+
-+ /* new dentry will be d_put'ed later by the vfs
-+ * so don't do it here
-+ * dput(dtohd(new_dentry));
-+ */
-+ dtohd(old_dentry) = NULL;
-+ dtopd(old_dentry)->state = DEL_REWRITTEN;
-+ }
-+ /* new dentry state = UNMODIFIED */
-+ else if(dtopd(new_dentry)->state == UNMODIFIED) {
-+ if(get_neg_sto_dentry(new_dentry))
-+ return -EINVAL;
-+
-+ meta_add_d_entry(new_dentry->d_parent,
-+ new_dentry->d_name.name,
-+ new_dentry->d_name.len);
-+
-+ /* is this right??? */
-+ /*dput(dtohd(new_dentry));*/
-+ dtohd(old_dentry) = NULL;
-+ dtopd(old_dentry)->state = DEL_REWRITTEN;
-+ }
-+ /* new dentry state = CREATED */
-+ else if(dtopd(new_dentry)->state == CREATED) {
-+ /* we keep the neg. base dentry (if exists) */
-+ dtohd(old_dentry) = dtohd(new_dentry);
-+ /* ...and set it to Null, or we'll get
-+ * dcache.c:345 if it gets dput twice... */
-+ dtohd(new_dentry) = NULL;
-+ dtopd(old_dentry)->state = CREATED;
-+ }
-+ /* new dentry state = NON_EXISTANT */
-+ else if(dtopd(new_dentry)->state == NON_EXISTANT) {
-+ if(get_neg_sto_dentry(new_dentry))
-+ return -EINVAL;
-+
-+ /* we keep the neg. base dentry (if exists) */
-+ dtohd(old_dentry) = dtohd(new_dentry);
-+ /* ...and set it to Null, or we'll get
-+ * Dr. dcache.c:345 if it gets dput twice... */
-+ dtohd(new_dentry) = NULL;
-+ dtopd(old_dentry)->state = CREATED;
-+ }
-+ /* new dentry state = DEL_REWRITTEN or DELETED */
-+ else if(dtopd(new_dentry)->state == DEL_REWRITTEN ||
-+ dtopd(new_dentry)->state == DELETED) {
-+ dtohd(old_dentry) = NULL;
-+ dtopd(old_dentry)->state = DEL_REWRITTEN;
-+ }
-+ else { /* not possible, uhh, ahh */
-+ printk(KERN_CRIT
-+ "mini_fo: rename_reg_file: invalid state detected [1].\n");
-+ return -1;
-+ }
-+
-+ /* now we definitely have a sto file */
-+ hidden_old_dentry = dtohd2(old_dentry);
-+ hidden_new_dentry = dtohd2(new_dentry);
-+
-+ dget(hidden_old_dentry);
-+ dget(hidden_new_dentry);
-+
-+ hidden_old_dir_dentry = dget(hidden_old_dentry->d_parent);
-+ hidden_new_dir_dentry = dget(hidden_new_dentry->d_parent);
-+ double_lock(hidden_old_dir_dentry, hidden_new_dir_dentry);
-+
-+ err = vfs_rename(hidden_old_dir_dentry->d_inode,
-+ hidden_old_dentry,
-+ hidden_new_dir_dentry->d_inode,
-+ hidden_new_dentry);
-+ if(err)
-+ goto out_lock;
-+
-+ fist_copy_attr_all(new_dir, hidden_new_dir_dentry->d_inode);
-+ if (new_dir != old_dir)
-+ fist_copy_attr_all(old_dir, hidden_old_dir_dentry->d_inode);
-+
-+ out_lock:
-+ /* double_unlock will dput the new/old parent dentries
-+ * whose refcnts were incremented via get_parent above.
-+ */
-+ double_unlock(hidden_old_dir_dentry, hidden_new_dir_dentry);
-+ dput(hidden_new_dentry);
-+ dput(hidden_old_dentry);
-+ out:
-+ return err;
-+ }
-+ else { /* invalid state */
-+ printk(KERN_CRIT "mini_fo: rename_reg_file: ERROR: invalid state detected [2].\n");
-+ return -1;
-+ }
-+}
-+
-+
-+STATIC int
-+mini_fo_readlink(dentry_t *dentry, char *buf, int bufsiz)
-+{
-+ int err=0;
-+ dentry_t *hidden_dentry = NULL;
-+
-+ if(dtohd2(dentry) && dtohd2(dentry)->d_inode) {
-+ hidden_dentry = dtohd2(dentry);
-+ } else if(dtohd(dentry) && dtohd(dentry)->d_inode) {
-+ hidden_dentry = dtohd(dentry);
-+ } else {
-+ goto out;
-+ }
-+
-+ if (!hidden_dentry->d_inode->i_op ||
-+ !hidden_dentry->d_inode->i_op->readlink) {
-+ err = -EINVAL; goto out;
-+ }
-+
-+ err = hidden_dentry->d_inode->i_op->readlink(hidden_dentry,
-+ buf,
-+ bufsiz);
-+ if (err > 0)
-+ fist_copy_attr_atime(dentry->d_inode, hidden_dentry->d_inode);
-+
-+ out:
-+ return err;
-+}
-+
-+
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,13)
-+static int mini_fo_follow_link(dentry_t *dentry, struct nameidata *nd)
-+#else
-+static void* mini_fo_follow_link(dentry_t *dentry, struct nameidata *nd)
-+#endif
-+{
-+ char *buf;
-+ int len = PAGE_SIZE, err;
-+ mm_segment_t old_fs;
-+
-+ /* in 2.6 this is freed by mini_fo_put_link called by __do_follow_link */
-+ buf = kmalloc(len, GFP_KERNEL);
-+ if (!buf) {
-+ err = -ENOMEM;
-+ goto out;
-+ }
-+
-+ /* read the symlink, and then we will follow it */
-+ old_fs = get_fs();
-+ set_fs(KERNEL_DS);
-+ err = dentry->d_inode->i_op->readlink(dentry, buf, len);
-+ set_fs(old_fs);
-+ if (err < 0) {
-+ kfree(buf);
-+ buf = NULL;
-+ goto out;
-+ }
-+ buf[err] = 0;
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ nd_set_link(nd, buf);
-+ err = 0;
-+#else
-+ err = vfs_follow_link(nd, buf);
-+#endif
-+
-+ out:
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-+ kfree(buf);
-+#endif
-+
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,13)
-+ return err;
-+#else
-+ return ERR_PTR(err);
-+#endif
-+}
-+
-+STATIC
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,13)
-+void mini_fo_put_link(struct dentry *dentry, struct nameidata *nd)
-+#else
-+void mini_fo_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
-+#endif
-+{
-+ char *link;
-+ link = nd_get_link(nd);
-+ kfree(link);
-+}
-+#endif
-+
-+STATIC int
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+mini_fo_permission(inode_t *inode, int mask, struct nameidata *nd)
-+#else
-+mini_fo_permission(inode_t *inode, int mask)
-+#endif
-+{
-+ inode_t *hidden_inode;
-+ int mode;
-+ int err;
-+
-+ if(itohi2(inode)) {
-+ hidden_inode = itohi2(inode);
-+ } else {
-+ hidden_inode = itohi(inode);
-+ }
-+ mode = inode->i_mode;
-+
-+ /* not really needed, as permission handles everything:
-+ * err = vfs_permission(inode, mask);
-+ * if (err)
-+ * goto out;
-+ */
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ err = permission(hidden_inode, mask, nd);
-+#else
-+ err = permission(hidden_inode, mask);
-+#endif
-+
-+ /* out: */
-+ return err;
-+}
-+
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-+STATIC int
-+mini_fo_inode_revalidate(dentry_t *dentry)
-+{
-+ int err = 0;
-+ dentry_t *hidden_dentry;
-+ inode_t *hidden_inode;
-+
-+ ASSERT(dentry->d_inode);
-+ ASSERT(itopd(dentry->d_inode));
-+
-+ if(itohi2(dentry->d_inode)) {
-+ hidden_dentry = dtohd2(dentry);
-+ hidden_inode = hidden_dentry->d_inode;
-+ } else if(itohi(dentry->d_inode)) {
-+ hidden_dentry = dtohd(dentry);
-+ hidden_inode = hidden_dentry->d_inode;
-+ } else {
-+ printk(KERN_CRIT "mini_fo_inode_revalidate: ERROR, invalid state detected.\n");
-+ err = -ENOENT;
-+ goto out;
-+ }
-+ if (hidden_inode && hidden_inode->i_op && hidden_inode->i_op->revalidate){
-+ err = hidden_inode->i_op->revalidate(hidden_dentry);
-+ if (err)
-+ goto out;
-+ }
-+ fist_copy_attr_all(dentry->d_inode, hidden_inode);
-+ out:
-+ return err;
-+}
-+#endif
-+
-+STATIC int
-+mini_fo_setattr(dentry_t *dentry, struct iattr *ia)
-+{
-+ int err = 0;
-+
-+ check_mini_fo_dentry(dentry);
-+
-+ if(!is_mini_fo_existant(dentry)) {
-+ printk(KERN_CRIT "mini_fo_setattr: ERROR, invalid state detected [1].\n");
-+ goto out;
-+ }
-+
-+ if(dtost(dentry) == UNMODIFIED) {
-+ if(!IS_COPY_FLAG(ia->ia_valid))
-+ goto out; /* we ignore these changes to base */
-+
-+ if(S_ISDIR(dentry->d_inode->i_mode)) {
-+ err = dir_unmod_to_mod(dentry);
-+ } else {
-+ /* we copy contents if file is not beeing truncated */
-+ if(S_ISREG(dentry->d_inode->i_mode) &&
-+ !(ia->ia_size == 0 && (ia->ia_valid & ATTR_SIZE))) {
-+ err = nondir_unmod_to_mod(dentry, 1);
-+ } else
-+ err = nondir_unmod_to_mod(dentry, 0);
-+ }
-+ if(err) {
-+ err = -EINVAL;
-+ printk(KERN_CRIT "mini_fo_setattr: ERROR changing states.\n");
-+ goto out;
-+ }
-+ }
-+ if(!exists_in_storage(dentry)) {
-+ printk(KERN_CRIT "mini_fo_setattr: ERROR, invalid state detected [2].\n");
-+ err = -EINVAL;
-+ goto out;
-+ }
-+ ASSERT(dentry->d_inode);
-+ ASSERT(dtohd2(dentry));
-+ ASSERT(itopd(dentry->d_inode));
-+ ASSERT(itohi2(dentry->d_inode));
-+
-+ err = notify_change(dtohd2(dentry), ia);
-+ fist_copy_attr_all(dentry->d_inode, itohi2(dentry->d_inode));
-+ out:
-+ return err;
-+}
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+STATIC int
-+mini_fo_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
-+{
-+ int err = 0;
-+ dentry_t *hidden_dentry;
-+
-+ ASSERT(dentry->d_inode);
-+ ASSERT(itopd(dentry->d_inode));
-+
-+ if(itohi2(dentry->d_inode)) {
-+ hidden_dentry = dtohd2(dentry);
-+ } else if(itohi(dentry->d_inode)) {
-+ hidden_dentry = dtohd(dentry);
-+ } else {
-+ printk(KERN_CRIT "mini_fo_getattr: ERROR, invalid state detected.\n");
-+ err = -ENOENT;
-+ goto out;
-+ }
-+ fist_copy_attr_all(dentry->d_inode, hidden_dentry->d_inode);
-+
-+ ASSERT(hidden_dentry);
-+ ASSERT(hidden_dentry->d_inode);
-+ ASSERT(hidden_dentry->d_inode->i_op);
-+
-+ generic_fillattr(dentry->d_inode, stat);
-+ if (!stat->blksize) {
-+ struct super_block *s = hidden_dentry->d_inode->i_sb;
-+ unsigned blocks;
-+ blocks = (stat->size+s->s_blocksize-1) >> s->s_blocksize_bits;
-+ stat->blocks = (s->s_blocksize / 512) * blocks;
-+ stat->blksize = s->s_blocksize;
-+ }
-+ out:
-+ return err;
-+}
-+#endif
-+
-+#if defined(XATTR) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20))
-+#if 0 /* no xattr_alloc() and xattr_free() */
-+/* This is lifted from fs/xattr.c */
-+static void *
-+xattr_alloc(size_t size, size_t limit)
-+{
-+ void *ptr;
-+
-+ if (size > limit)
-+ return ERR_PTR(-E2BIG);
-+
-+ if (!size) /* size request, no buffer is needed */
-+ return NULL;
-+ else if (size <= PAGE_SIZE)
-+ ptr = kmalloc((unsigned long) size, GFP_KERNEL);
-+ else
-+ ptr = vmalloc((unsigned long) size);
-+ if (!ptr)
-+ return ERR_PTR(-ENOMEM);
-+ return ptr;
-+}
-+
-+static void
-+xattr_free(void *ptr, size_t size)
-+{
-+ if (!size) /* size request, no buffer was needed */
-+ return;
-+ else if (size <= PAGE_SIZE)
-+ kfree(ptr);
-+ else
-+ vfree(ptr);
-+}
-+#endif /* no xattr_alloc() and xattr_free() */
-+
-+/* BKL held by caller.
-+ * dentry->d_inode->i_sem down
-+ */
-+STATIC int
-+mini_fo_getxattr(struct dentry *dentry, const char *name, void *value, size_t size) {
-+ struct dentry *hidden_dentry = NULL;
-+ int err = -EOPNOTSUPP;
-+ /* Define these anyway so we don't need as much ifdef'ed code. */
-+ char *encoded_name = NULL;
-+ char *encoded_value = NULL;
-+
-+ check_mini_fo_dentry(dentry);
-+
-+ if(exists_in_storage(dentry))
-+ hidden_dentry = dtohd2(dentry);
-+ else
-+ hidden_dentry = dtohd(dentry);
-+
-+ ASSERT(hidden_dentry);
-+ ASSERT(hidden_dentry->d_inode);
-+ ASSERT(hidden_dentry->d_inode->i_op);
-+
-+ if (hidden_dentry->d_inode->i_op->getxattr) {
-+ encoded_name = (char *)name;
-+ encoded_value = (char *)value;
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_dentry->d_inode->i_sem);
-+#endif
-+ /* lock_kernel() already done by caller. */
-+ err = hidden_dentry->d_inode->i_op->getxattr(hidden_dentry, encoded_name, encoded_value, size);
-+ /* unlock_kernel() will be done by caller. */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_dentry->d_inode->i_sem);
-+#endif
-+ }
-+ return err;
-+}
-+
-+/* BKL held by caller.
-+ * dentry->d_inode->i_sem down
-+ */
-+STATIC int
-+#if ((LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,21) \
-+ && LINUX_VERSION_CODE <= KERNEL_VERSION(2,4,23)) \
-+ || LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0))
-+mini_fo_setxattr(struct dentry *dentry, const char *name,
-+ const void *value, size_t size, int flags)
-+#else
-+mini_fo_setxattr(struct dentry *dentry, const char *name,
-+ void *value, size_t size, int flags)
-+#endif
-+
-+{
-+ struct dentry *hidden_dentry = NULL;
-+ int err = -EOPNOTSUPP;
-+
-+ /* Define these anyway, so we don't have as much ifdef'ed code. */
-+ char *encoded_value = NULL;
-+ char *encoded_name = NULL;
-+
-+ check_mini_fo_dentry(dentry);
-+
-+ if(exists_in_storage(dentry))
-+ hidden_dentry = dtohd2(dentry);
-+ else
-+ hidden_dentry = dtohd(dentry);
-+
-+ ASSERT(hidden_dentry);
-+ ASSERT(hidden_dentry->d_inode);
-+ ASSERT(hidden_dentry->d_inode->i_op);
-+
-+ if (hidden_dentry->d_inode->i_op->setxattr) {
-+ encoded_name = (char *)name;
-+ encoded_value = (char *)value;
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_dentry->d_inode->i_sem);
-+#endif
-+ /* lock_kernel() already done by caller. */
-+ err = hidden_dentry->d_inode->i_op->setxattr(hidden_dentry, encoded_name, encoded_value, size, flags);
-+ /* unlock_kernel() will be done by caller. */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_dentry->d_inode->i_sem);
-+#endif
-+ }
-+ return err;
-+}
-+
-+/* BKL held by caller.
-+ * dentry->d_inode->i_sem down
-+ */
-+STATIC int
-+mini_fo_removexattr(struct dentry *dentry, const char *name) {
-+ struct dentry *hidden_dentry = NULL;
-+ int err = -EOPNOTSUPP;
-+ char *encoded_name;
-+
-+ check_mini_fo_dentry(dentry);
-+
-+ if(exists_in_storage(dentry))
-+ hidden_dentry = dtohd2(dentry);
-+ else
-+ hidden_dentry = dtohd(dentry);
-+
-+ ASSERT(hidden_dentry);
-+ ASSERT(hidden_dentry->d_inode);
-+ ASSERT(hidden_dentry->d_inode->i_op);
-+
-+ if (hidden_dentry->d_inode->i_op->removexattr) {
-+ encoded_name = (char *)name;
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_dentry->d_inode->i_sem);
-+#endif
-+ /* lock_kernel() already done by caller. */
-+ err = hidden_dentry->d_inode->i_op->removexattr(hidden_dentry, encoded_name);
-+ /* unlock_kernel() will be done by caller. */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_dentry->d_inode->i_sem);
-+#endif
-+ }
-+ return err;
-+}
-+
-+/* BKL held by caller.
-+ * dentry->d_inode->i_sem down
-+ */
-+STATIC int
-+mini_fo_listxattr(struct dentry *dentry, char *list, size_t size) {
-+ struct dentry *hidden_dentry = NULL;
-+ int err = -EOPNOTSUPP;
-+ char *encoded_list = NULL;
-+
-+ check_mini_fo_dentry(dentry);
-+
-+ if(exists_in_storage(dentry))
-+ hidden_dentry = dtohd2(dentry);
-+ else
-+ hidden_dentry = dtohd(dentry);
-+
-+ ASSERT(hidden_dentry);
-+ ASSERT(hidden_dentry->d_inode);
-+ ASSERT(hidden_dentry->d_inode->i_op);
-+
-+ if (hidden_dentry->d_inode->i_op->listxattr) {
-+ encoded_list = list;
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_dentry->d_inode->i_sem);
-+#endif
-+ /* lock_kernel() already done by caller. */
-+ err = hidden_dentry->d_inode->i_op->listxattr(hidden_dentry, encoded_list, size);
-+ /* unlock_kernel() will be done by caller. */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_dentry->d_inode->i_sem);
-+#endif
-+ }
-+ return err;
-+}
-+# endif /* defined(XATTR) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20)) */
-+
-+struct inode_operations mini_fo_symlink_iops =
-+ {
-+ readlink: mini_fo_readlink,
-+ follow_link: mini_fo_follow_link,
-+ /* mk: permission: mini_fo_permission, */
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-+ revalidate: mini_fo_inode_revalidate,
-+#endif
-+ setattr: mini_fo_setattr,
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ getattr: mini_fo_getattr,
-+ put_link: mini_fo_put_link,
-+#endif
-+
-+#if defined(XATTR) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20))
-+ setxattr: mini_fo_setxattr,
-+ getxattr: mini_fo_getxattr,
-+ listxattr: mini_fo_listxattr,
-+ removexattr: mini_fo_removexattr
-+# endif /* defined(XATTR) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20)) */
-+ };
-+
-+struct inode_operations mini_fo_dir_iops =
-+ {
-+ create: mini_fo_create,
-+ lookup: mini_fo_lookup,
-+ link: mini_fo_link,
-+ unlink: mini_fo_unlink,
-+ symlink: mini_fo_symlink,
-+ mkdir: mini_fo_mkdir,
-+ rmdir: mini_fo_rmdir,
-+ mknod: mini_fo_mknod,
-+ rename: mini_fo_rename,
-+ /* no readlink/follow_link for non-symlinks */
-+ // off because we have setattr
-+ // truncate: mini_fo_truncate,
-+ /* mk:permission: mini_fo_permission, */
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-+ revalidate: mini_fo_inode_revalidate,
-+#endif
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ getattr: mini_fo_getattr,
-+#endif
-+ setattr: mini_fo_setattr,
-+#if defined(XATTR) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20))
-+ setxattr: mini_fo_setxattr,
-+ getxattr: mini_fo_getxattr,
-+ listxattr: mini_fo_listxattr,
-+ removexattr: mini_fo_removexattr
-+# endif /* XATTR && LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20) */
-+ };
-+
-+struct inode_operations mini_fo_main_iops =
-+ {
-+ /* permission: mini_fo_permission, */
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-+ revalidate: mini_fo_inode_revalidate,
-+#endif
-+ setattr: mini_fo_setattr,
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ getattr: mini_fo_getattr,
-+#endif
-+#if defined(XATTR) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20))
-+ setxattr: mini_fo_setxattr,
-+ getxattr: mini_fo_getxattr,
-+ listxattr: mini_fo_listxattr,
-+ removexattr: mini_fo_removexattr
-+# endif /* XATTR && LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,20) */
-+ };
---- /dev/null
-+++ b/fs/mini_fo/main.c
-@@ -0,0 +1,423 @@
-+/*
-+ * Copyright (c) 1997-2003 Erez Zadok
-+ * Copyright (c) 2001-2003 Stony Brook University
-+ *
-+ * For specific licensing information, see the COPYING file distributed with
-+ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
-+ *
-+ * This Copyright notice must be kept intact and distributed with all
-+ * fistgen sources INCLUDING sources generated by fistgen.
-+ */
-+/*
-+ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
-+ *
-+ * This program is free software; you can redistribute it and/or
-+ * modify it under the terms of the GNU General Public License
-+ * as published by the Free Software Foundation; either version
-+ * 2 of the License, or (at your option) any later version.
-+ */
-+
-+/*
-+ * $Id$
-+ */
-+
-+#ifdef HAVE_CONFIG_H
-+# include <config.h>
-+#endif
-+
-+#include "fist.h"
-+#include "mini_fo.h"
-+#include <linux/module.h>
-+
-+/* This definition must only appear after we include <linux/module.h> */
-+#ifndef MODULE_LICENSE
-+# define MODULE_LICENSE(bison)
-+#endif /* not MODULE_LICENSE */
-+
-+/*
-+ * This is the mini_fo tri interpose function, which extends the
-+ * functionality of the regular interpose by interposing a higher
-+ * level inode on top of two lower level ones: the base filesystem
-+ * inode and the storage filesystem inode.
-+ *
-+ * sb we pass is mini_fo's super_block
-+ */
-+int
-+mini_fo_tri_interpose(dentry_t *hidden_dentry,
-+ dentry_t *hidden_sto_dentry,
-+ dentry_t *dentry, super_block_t *sb, int flag)
-+{
-+ inode_t *hidden_inode = NULL;
-+ inode_t *hidden_sto_inode = NULL; /* store corresponding storage inode */
-+ int err = 0;
-+ inode_t *inode;
-+
-+ /* Pointer to hidden_sto_inode if exists, else to hidden_inode.
-+ * This is used to copy the attributes of the correct inode. */
-+ inode_t *master_inode;
-+
-+ if(hidden_dentry)
-+ hidden_inode = hidden_dentry->d_inode;
-+ if(hidden_sto_dentry)
-+ hidden_sto_inode = hidden_sto_dentry->d_inode;
-+
-+ ASSERT(dentry->d_inode == NULL);
-+
-+ /* mk: One of the inodes associated with the dentrys is likely to
-+ * be NULL, so carefull:
-+ */
-+ ASSERT((hidden_inode != NULL) || (hidden_sto_inode != NULL));
-+
-+ if(hidden_sto_inode)
-+ master_inode = hidden_sto_inode;
-+ else
-+ master_inode = hidden_inode;
-+
-+ /*
-+ * We allocate our new inode below, by calling iget.
-+ * iget will call our read_inode which will initialize some
-+ * of the new inode's fields
-+ */
-+
-+ /*
-+ * original: inode = iget(sb, hidden_inode->i_ino);
-+ */
-+ inode = iget(sb, iunique(sb, 25));
-+ if (!inode) {
-+ err = -EACCES; /* should be impossible??? */
-+ goto out;
-+ }
-+
-+ /*
-+ * interpose the inode if not already interposed
-+ * this is possible if the inode is being reused
-+ * XXX: what happens if we get_empty_inode() but there's another already?
-+ * for now, ASSERT() that this can't happen; fix later.
-+ */
-+ if (itohi(inode) != NULL) {
-+ printk(KERN_CRIT "mini_fo_tri_interpose: itohi(inode) != NULL.\n");
-+ }
-+ if (itohi2(inode) != NULL) {
-+ printk(KERN_CRIT "mini_fo_tri_interpose: itohi2(inode) != NULL.\n");
-+ }
-+
-+ /* mk: Carefull, igrab can't handle NULL inodes (ok, why should it?), so
-+ * we need to check here:
-+ */
-+ if(hidden_inode)
-+ itohi(inode) = igrab(hidden_inode);
-+ else
-+ itohi(inode) = NULL;
-+
-+ if(hidden_sto_inode)
-+ itohi2(inode) = igrab(hidden_sto_inode);
-+ else
-+ itohi2(inode) = NULL;
-+
-+
-+ /* Use different set of inode ops for symlinks & directories*/
-+ if (S_ISLNK(master_inode->i_mode))
-+ inode->i_op = &mini_fo_symlink_iops;
-+ else if (S_ISDIR(master_inode->i_mode))
-+ inode->i_op = &mini_fo_dir_iops;
-+
-+ /* Use different set of file ops for directories */
-+ if (S_ISDIR(master_inode->i_mode))
-+ inode->i_fop = &mini_fo_dir_fops;
-+
-+ /* properly initialize special inodes */
-+ if (S_ISBLK(master_inode->i_mode) || S_ISCHR(master_inode->i_mode) ||
-+ S_ISFIFO(master_inode->i_mode) || S_ISSOCK(master_inode->i_mode)) {
-+ init_special_inode(inode, master_inode->i_mode, master_inode->i_rdev);
-+ }
-+
-+ /* Fix our inode's address operations to that of the lower inode */
-+ if (inode->i_mapping->a_ops != master_inode->i_mapping->a_ops) {
-+ inode->i_mapping->a_ops = master_inode->i_mapping->a_ops;
-+ }
-+
-+ /* only (our) lookup wants to do a d_add */
-+ if (flag)
-+ d_add(dentry, inode);
-+ else
-+ d_instantiate(dentry, inode);
-+
-+ ASSERT(dtopd(dentry) != NULL);
-+
-+ /* all well, copy inode attributes */
-+ fist_copy_attr_all(inode, master_inode);
-+
-+ out:
-+ return err;
-+}
-+
-+/* parse mount options "base=" and "sto=" */
-+dentry_t *
-+mini_fo_parse_options(super_block_t *sb, char *options)
-+{
-+ dentry_t *hidden_root = ERR_PTR(-EINVAL);
-+ dentry_t *hidden_root2 = ERR_PTR(-EINVAL);
-+ struct nameidata nd, nd2;
-+ char *name, *tmp, *end;
-+ int err = 0;
-+
-+ /* We don't want to go off the end of our arguments later on. */
-+ for (end = options; *end; end++);
-+
-+ while (options < end) {
-+ tmp = options;
-+ while (*tmp && *tmp != ',')
-+ tmp++;
-+ *tmp = '\0';
-+ if (!strncmp("base=", options, 5)) {
-+ name = options + 5;
-+ printk(KERN_INFO "mini_fo: using base directory: %s\n", name);
-+
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-+ if (path_init(name, LOOKUP_FOLLOW, &nd))
-+ err = path_walk(name, &nd);
-+#else
-+ err = path_lookup(name, LOOKUP_FOLLOW, &nd);
-+#endif
-+ if (err) {
-+ printk(KERN_CRIT "mini_fo: error accessing hidden directory '%s'\n", name);
-+ hidden_root = ERR_PTR(err);
-+ goto out;
-+ }
-+ hidden_root = nd.dentry;
-+ stopd(sb)->base_dir_dentry = nd.dentry;
-+ stopd(sb)->hidden_mnt = nd.mnt;
-+
-+ } else if(!strncmp("sto=", options, 4)) {
-+ /* parse the storage dir */
-+ name = options + 4;
-+ printk(KERN_INFO "mini_fo: using storage directory: %s\n", name);
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-+ if(path_init(name, LOOKUP_FOLLOW, &nd2))
-+ err = path_walk(name, &nd2);
-+#else
-+ err = path_lookup(name, LOOKUP_FOLLOW, &nd2);
-+#endif
-+ if(err) {
-+ printk(KERN_CRIT "mini_fo: error accessing hidden storage directory '%s'\n", name);
-+
-+ hidden_root2 = ERR_PTR(err);
-+ goto out;
-+ }
-+ hidden_root2 = nd2.dentry;
-+ stopd(sb)->storage_dir_dentry = nd2.dentry;
-+ stopd(sb)->hidden_mnt2 = nd2.mnt;
-+ stohs2(sb) = hidden_root2->d_sb;
-+
-+ /* validate storage dir, this is done in
-+ * mini_fo_read_super for the base directory.
-+ */
-+ if (IS_ERR(hidden_root2)) {
-+ printk(KERN_WARNING "mini_fo_parse_options: storage dentry lookup failed (err = %ld)\n", PTR_ERR(hidden_root2));
-+ goto out;
-+ }
-+ if (!hidden_root2->d_inode) {
-+ printk(KERN_WARNING "mini_fo_parse_options: no storage dir to interpose on.\n");
-+ goto out;
-+ }
-+ stohs2(sb) = hidden_root2->d_sb;
-+ } else {
-+ printk(KERN_WARNING "mini_fo: unrecognized option '%s'\n", options);
-+ hidden_root = ERR_PTR(-EINVAL);
-+ goto out;
-+ }
-+ options = tmp + 1;
-+ }
-+
-+ out:
-+ if(IS_ERR(hidden_root2))
-+ return hidden_root2;
-+ return hidden_root;
-+}
-+
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+static int
-+#else
-+super_block_t *
-+#endif
-+mini_fo_read_super(super_block_t *sb, void *raw_data, int silent)
-+{
-+ dentry_t *hidden_root;
-+ int err = 0;
-+
-+ if (!raw_data) {
-+ printk(KERN_WARNING "mini_fo_read_super: missing argument\n");
-+ err = -EINVAL;
-+ goto out;
-+ }
-+ /*
-+ * Allocate superblock private data
-+ */
-+ __stopd(sb) = kmalloc(sizeof(struct mini_fo_sb_info), GFP_KERNEL);
-+ if (!stopd(sb)) {
-+ printk(KERN_WARNING "%s: out of memory\n", __FUNCTION__);
-+ err = -ENOMEM;
-+ goto out;
-+ }
-+ stohs(sb) = NULL;
-+
-+ hidden_root = mini_fo_parse_options(sb, raw_data);
-+ if (IS_ERR(hidden_root)) {
-+ printk(KERN_WARNING "mini_fo_read_super: lookup_dentry failed (err = %ld)\n", PTR_ERR(hidden_root));
-+ err = PTR_ERR(hidden_root);
-+ goto out_free;
-+ }
-+ if (!hidden_root->d_inode) {
-+ printk(KERN_WARNING "mini_fo_read_super: no directory to interpose on\n");
-+ goto out_free;
-+ }
-+ stohs(sb) = hidden_root->d_sb;
-+
-+ /*
-+ * Linux 2.4.2-ac3 and beyond has code in
-+ * mm/filemap.c:generic_file_write() that requires sb->s_maxbytes
-+ * to be populated. If not set, all write()s under that sb will
-+ * return 0.
-+ *
-+ * Linux 2.4.4+ automatically sets s_maxbytes to MAX_NON_LFS;
-+ * the filesystem should override it only if it supports LFS.
-+ */
-+ /* non-SCA code is good to go with LFS */
-+ sb->s_maxbytes = hidden_root->d_sb->s_maxbytes;
-+
-+ sb->s_op = &mini_fo_sops;
-+ /*
-+ * we can't use d_alloc_root if we want to use
-+ * our own interpose function unchanged,
-+ * so we simply replicate *most* of the code in d_alloc_root here
-+ */
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-+ sb->s_root = d_alloc(NULL, &(const struct qstr) { "/", 1, 0 });
-+#else
-+ sb->s_root = d_alloc(NULL, &(const struct qstr){hash: 0, name: "/", len : 1});
-+#endif
-+ if (IS_ERR(sb->s_root)) {
-+ printk(KERN_WARNING "mini_fo_read_super: d_alloc failed\n");
-+ err = -ENOMEM;
-+ goto out_dput;
-+ }
-+
-+ sb->s_root->d_op = &mini_fo_dops;
-+ sb->s_root->d_sb = sb;
-+ sb->s_root->d_parent = sb->s_root;
-+
-+ /* link the upper and lower dentries */
-+ __dtopd(sb->s_root) = (struct mini_fo_dentry_info *)
-+ kmalloc(sizeof(struct mini_fo_dentry_info), GFP_KERNEL);
-+ if (!dtopd(sb->s_root)) {
-+ err = -ENOMEM;
-+ goto out_dput2;
-+ }
-+ dtopd(sb->s_root)->state = MODIFIED;
-+ dtohd(sb->s_root) = hidden_root;
-+
-+ /* fanout relevant, interpose on storage root dentry too */
-+ dtohd2(sb->s_root) = stopd(sb)->storage_dir_dentry;
-+
-+ /* ...and call tri-interpose to interpose root dir inodes
-+ * if (mini_fo_interpose(hidden_root, sb->s_root, sb, 0))
-+ */
-+ if(mini_fo_tri_interpose(hidden_root, dtohd2(sb->s_root), sb->s_root, sb, 0))
-+ goto out_dput2;
-+
-+ /* initalize the wol list */
-+ itopd(sb->s_root->d_inode)->deleted_list_size = -1;
-+ itopd(sb->s_root->d_inode)->renamed_list_size = -1;
-+ meta_build_lists(sb->s_root);
-+
-+ goto out;
-+
-+ out_dput2:
-+ dput(sb->s_root);
-+ out_dput:
-+ dput(hidden_root);
-+ dput(dtohd2(sb->s_root)); /* release the hidden_sto_dentry too */
-+ out_free:
-+ kfree(stopd(sb));
-+ __stopd(sb) = NULL;
-+ out:
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ return err;
-+#else
-+ if (err) {
-+ return ERR_PTR(err);
-+ } else {
-+ return sb;
-+ }
-+#endif
-+}
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
-+static int mini_fo_get_sb(struct file_system_type *fs_type,
-+ int flags, const char *dev_name,
-+ void *raw_data, struct vfsmount *mnt)
-+{
-+ return get_sb_nodev(fs_type, flags, raw_data, mini_fo_read_super, mnt);
-+}
-+#else
-+static struct super_block *mini_fo_get_sb(struct file_system_type *fs_type,
-+ int flags, const char *dev_name,
-+ void *raw_data)
-+{
-+ return get_sb_nodev(fs_type, flags, raw_data, mini_fo_read_super);
-+}
-+#endif
-+
-+void mini_fo_kill_block_super(struct super_block *sb)
-+{
-+ generic_shutdown_super(sb);
-+ /*
-+ * XXX: BUG: Halcrow: Things get unstable sometime after this point:
-+ * lib/rwsem-spinlock.c:127: spin_is_locked on uninitialized
-+ * fs/fs-writeback.c:402: spin_lock(fs/super.c:a0381828) already
-+ * locked by fs/fs-writeback.c/402
-+ *
-+ * Apparently, someone's not releasing a lock on sb_lock...
-+ */
-+}
-+
-+static struct file_system_type mini_fo_fs_type = {
-+ .owner = THIS_MODULE,
-+ .name = "mini_fo",
-+ .get_sb = mini_fo_get_sb,
-+ .kill_sb = mini_fo_kill_block_super,
-+ .fs_flags = 0,
-+};
-+
-+
-+#else
-+static DECLARE_FSTYPE(mini_fo_fs_type, "mini_fo", mini_fo_read_super, 0);
-+#endif
-+
-+static int __init init_mini_fo_fs(void)
-+{
-+ printk("Registering mini_fo version $Id$\n");
-+ return register_filesystem(&mini_fo_fs_type);
-+}
-+static void __exit exit_mini_fo_fs(void)
-+{
-+ printk("Unregistering mini_fo version $Id$\n");
-+ unregister_filesystem(&mini_fo_fs_type);
-+}
-+
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-+EXPORT_NO_SYMBOLS;
-+#endif
-+
-+MODULE_AUTHOR("Erez Zadok <ezk@cs.sunysb.edu>");
-+MODULE_DESCRIPTION("FiST-generated mini_fo filesystem");
-+MODULE_LICENSE("GPL");
-+
-+/* MODULE_PARM(fist_debug_var, "i"); */
-+/* MODULE_PARM_DESC(fist_debug_var, "Debug level"); */
-+
-+module_init(init_mini_fo_fs)
-+module_exit(exit_mini_fo_fs)
---- /dev/null
-+++ b/fs/mini_fo/Makefile
-@@ -0,0 +1,17 @@
-+#
-+# Makefile for mini_fo 2.4 and 2.6 Linux kernels
-+#
-+# Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
-+#
-+# This program is free software; you can redistribute it and/or
-+# modify it under the terms of the GNU General Public License
-+# as published by the Free Software Foundation; either version
-+# 2 of the License, or (at your option) any later version.
-+#
-+
-+obj-$(CONFIG_MINI_FO) := mini_fo.o
-+mini_fo-objs := meta.o dentry.o file.o inode.o main.o super.o state.o aux.o
-+
-+# dependencies
-+${mini_fo-objs}: mini_fo.h fist.h
-+
---- /dev/null
-+++ b/fs/mini_fo/meta.c
-@@ -0,0 +1,1000 @@
-+/*
-+ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
-+ *
-+ * This program is free software; you can redistribute it and/or
-+ * modify it under the terms of the GNU General Public License
-+ * as published by the Free Software Foundation; either version
-+ * 2 of the License, or (at your option) any later version.
-+ */
-+
-+#ifdef HAVE_CONFIG_H
-+# include <config.h>
-+#endif /* HAVE_CONFIG_H */
-+#include "fist.h"
-+#include "mini_fo.h"
-+
-+int meta_build_lists(dentry_t *dentry)
-+{
-+ struct mini_fo_inode_info *inode_info;
-+
-+ dentry_t *meta_dentry = 0;
-+ file_t *meta_file = 0;
-+ mm_segment_t old_fs;
-+ void *buf;
-+
-+ int bytes, len;
-+ struct vfsmount *meta_mnt;
-+ char *entry;
-+
-+ inode_info = itopd(dentry->d_inode);
-+ if(!(inode_info->deleted_list_size == -1 &&
-+ inode_info->renamed_list_size == -1)) {
-+ printk(KERN_CRIT "mini_fo: meta_build_lists: \
-+ Error, list(s) not virgin.\n");
-+ return -1;
-+ }
-+
-+ /* init our meta lists */
-+ INIT_LIST_HEAD(&inode_info->deleted_list);
-+ inode_info->deleted_list_size = 0;
-+
-+ INIT_LIST_HEAD(&inode_info->renamed_list);
-+ inode_info->renamed_list_size = 0;
-+
-+ /* might there be a META-file? */
-+ if(dtohd2(dentry) && dtohd2(dentry)->d_inode) {
-+ meta_dentry = lookup_one_len(META_FILENAME,
-+ dtohd2(dentry),
-+ strlen(META_FILENAME));
-+ if(!meta_dentry->d_inode) {
-+ dput(meta_dentry);
-+ goto out_ok;
-+ }
-+ /* $%& err, is this correct? */
-+ meta_mnt = stopd(dentry->d_inode->i_sb)->hidden_mnt2;
-+ mntget(meta_mnt);
-+
-+
-+ /* open META-file for reading */
-+ meta_file = dentry_open(meta_dentry, meta_mnt, 0x0);
-+ if(!meta_file || IS_ERR(meta_file)) {
-+ printk(KERN_CRIT "mini_fo: meta_build_lists: \
-+ ERROR opening META file.\n");
-+ goto out_err;
-+ }
-+
-+ /* check if fs supports reading */
-+ if(!meta_file->f_op->read) {
-+ printk(KERN_CRIT "mini_fo: meta_build_lists: \
-+ ERROR, fs does not support reading.\n");
-+ goto out_err_close;
-+ }
-+
-+ /* allocate a page for transfering the data */
-+ buf = (void *) __get_free_page(GFP_KERNEL);
-+ if(!buf) {
-+ printk(KERN_CRIT "mini_fo: meta_build_lists: \
-+ ERROR, out of mem.\n");
-+ goto out_err_close;
-+ }
-+ meta_file->f_pos = 0;
-+ old_fs = get_fs();
-+ set_fs(KERNEL_DS);
-+ do {
-+ char *c;
-+ bytes = meta_file->f_op->read(meta_file, buf, PAGE_SIZE, &meta_file->f_pos);
-+ if(bytes == PAGE_SIZE) {
-+ /* trim a cut off filename and adjust f_pos to get it next time */
-+ for(c = (char*) buf+PAGE_SIZE;
-+ *c != '\n';
-+ c--, bytes--, meta_file->f_pos--);
-+ }
-+ entry = (char *) buf;
-+ while(entry < (char *) buf+bytes) {
-+
-+ char *old_path;
-+ char *dir_name;
-+ int old_len, new_len;
-+
-+ /* len without '\n'*/
-+ len = (int) (strchr(entry, '\n') - entry);
-+ switch (*entry) {
-+ case 'D':
-+ /* format: "D filename" */
-+ meta_list_add_d_entry(dentry,
-+ entry+2,
-+ len-2);
-+ break;
-+ case 'R':
-+ /* format: "R path/xy/dir newDir" */
-+ old_path = entry+2;
-+ dir_name = strchr(old_path, ' ') + 1;
-+ old_len = dir_name - old_path - 1;
-+ new_len = ((int) entry) + len - ((int ) dir_name);
-+ meta_list_add_r_entry(dentry,
-+ old_path,
-+ old_len,
-+ dir_name,
-+ new_len);
-+ break;
-+ default:
-+ /* unknown entry type detected */
-+ break;
-+ }
-+ entry += len+1;
-+ }
-+
-+ } while(meta_file->f_pos < meta_dentry->d_inode->i_size);
-+
-+ free_page((unsigned long) buf);
-+ set_fs(old_fs);
-+ fput(meta_file);
-+ }
-+ goto out_ok;
-+
-+ out_err_close:
-+ fput(meta_file);
-+ out_err:
-+ mntput(meta_mnt);
-+ dput(meta_dentry);
-+ return -1;
-+ out_ok:
-+ return 1; /* check this!!! inode_info->wol_size; */
-+}
-+
-+/* cleanups up all lists and free's the mem by dentry */
-+int meta_put_lists(dentry_t *dentry)
-+{
-+ if(!dentry || !dentry->d_inode) {
-+ printk("mini_fo: meta_put_lists: invalid dentry passed.\n");
-+ return -1;
-+ }
-+ return __meta_put_lists(dentry->d_inode);
-+}
-+
-+/* cleanups up all lists and free's the mem by inode */
-+int __meta_put_lists(inode_t *inode)
-+{
-+ int err = 0;
-+ if(!inode || !itopd(inode)) {
-+ printk("mini_fo: __meta_put_lists: invalid inode passed.\n");
-+ return -1;
-+ }
-+ err = __meta_put_d_list(inode);
-+ err |= __meta_put_r_list(inode);
-+ return err;
-+}
-+
-+int meta_sync_lists(dentry_t *dentry)
-+{
-+ int err = 0;
-+ if(!dentry || !dentry->d_inode) {
-+ printk("mini_fo: meta_sync_lists: \
-+ invalid dentry passed.\n");
-+ return -1;
-+ }
-+ err = meta_sync_d_list(dentry, 0);
-+ err |= meta_sync_r_list(dentry, 1);
-+ return err;
-+}
-+
-+
-+/* remove all D entries from the renamed list and free the mem */
-+int __meta_put_d_list(inode_t *inode)
-+{
-+ struct list_head *tmp;
-+ struct deleted_entry *del_entry;
-+ struct mini_fo_inode_info *inode_info;
-+
-+ if(!inode || !itopd(inode)) {
-+ printk(KERN_CRIT "mini_fo: __meta_put_d_list: \
-+ invalid inode passed.\n");
-+ return -1;
-+ }
-+ inode_info = itopd(inode);
-+
-+ /* nuke the DELETED-list */
-+ if(inode_info->deleted_list_size <= 0)
-+ return 0;
-+
-+ while(!list_empty(&inode_info->deleted_list)) {
-+ tmp = inode_info->deleted_list.next;
-+ list_del(tmp);
-+ del_entry = list_entry(tmp, struct deleted_entry, list);
-+ kfree(del_entry->name);
-+ kfree(del_entry);
-+ }
-+ inode_info->deleted_list_size = 0;
-+
-+ return 0;
-+}
-+
-+/* remove all R entries from the renamed list and free the mem */
-+int __meta_put_r_list(inode_t *inode)
-+{
-+ struct list_head *tmp;
-+ struct renamed_entry *ren_entry;
-+ struct mini_fo_inode_info *inode_info;
-+
-+ if(!inode || !itopd(inode)) {
-+ printk(KERN_CRIT "mini_fo: meta_put_r_list: invalid inode.\n");
-+ return -1;
-+ }
-+ inode_info = itopd(inode);
-+
-+ /* nuke the RENAMED-list */
-+ if(inode_info->renamed_list_size <= 0)
-+ return 0;
-+
-+ while(!list_empty(&inode_info->renamed_list)) {
-+ tmp = inode_info->renamed_list.next;
-+ list_del(tmp);
-+ ren_entry = list_entry(tmp, struct renamed_entry, list);
-+ kfree(ren_entry->new_name);
-+ kfree(ren_entry->old_name);
-+ kfree(ren_entry);
-+ }
-+ inode_info->renamed_list_size = 0;
-+
-+ return 0;
-+}
-+
-+int meta_add_d_entry(dentry_t *dentry, const char *name, int len)
-+{
-+ int err = 0;
-+ err = meta_list_add_d_entry(dentry, name, len);
-+ err |= meta_write_d_entry(dentry,name,len);
-+ return err;
-+}
-+
-+/* add a D entry to the deleted list */
-+int meta_list_add_d_entry(dentry_t *dentry, const char *name, int len)
-+{
-+ struct deleted_entry *del_entry;
-+ struct mini_fo_inode_info *inode_info;
-+
-+ if(!dentry || !dentry->d_inode) {
-+ printk(KERN_CRIT "mini_fo: meta_list_add_d_entry: \
-+ invalid dentry passed.\n");
-+ return -1;
-+ }
-+ inode_info = itopd(dentry->d_inode);
-+
-+ if(inode_info->deleted_list_size < 0)
-+ return -1;
-+
-+ del_entry = (struct deleted_entry *)
-+ kmalloc(sizeof(struct deleted_entry), GFP_KERNEL);
-+ del_entry->name = (char*) kmalloc(len, GFP_KERNEL);
-+ if(!del_entry || !del_entry->name) {
-+ printk(KERN_CRIT "mini_fo: meta_list_add_d_entry: \
-+ out of mem.\n");
-+ kfree(del_entry->name);
-+ kfree(del_entry);
-+ return -ENOMEM;
-+ }
-+
-+ strncpy(del_entry->name, name, len);
-+ del_entry->len = len;
-+
-+ list_add(&del_entry->list, &inode_info->deleted_list);
-+ inode_info->deleted_list_size++;
-+ return 0;
-+}
-+
-+int meta_add_r_entry(dentry_t *dentry,
-+ const char *old_name, int old_len,
-+ const char *new_name, int new_len)
-+{
-+ int err = 0;
-+ err = meta_list_add_r_entry(dentry,
-+ old_name, old_len,
-+ new_name, new_len);
-+ err |= meta_write_r_entry(dentry,
-+ old_name, old_len,
-+ new_name, new_len);
-+ return err;
-+}
-+
-+/* add a R entry to the renamed list */
-+int meta_list_add_r_entry(dentry_t *dentry,
-+ const char *old_name, int old_len,
-+ const char *new_name, int new_len)
-+{
-+ struct renamed_entry *ren_entry;
-+ struct mini_fo_inode_info *inode_info;
-+
-+ if(!dentry || !dentry->d_inode) {
-+ printk(KERN_CRIT "mini_fo: meta_list_add_r_entry: \
-+ invalid dentry passed.\n");
-+ return -1;
-+ }
-+ inode_info = itopd(dentry->d_inode);
-+
-+ if(inode_info->renamed_list_size < 0)
-+ return -1;
-+
-+ ren_entry = (struct renamed_entry *)
-+ kmalloc(sizeof(struct renamed_entry), GFP_KERNEL);
-+ ren_entry->old_name = (char*) kmalloc(old_len, GFP_KERNEL);
-+ ren_entry->new_name = (char*) kmalloc(new_len, GFP_KERNEL);
-+
-+ if(!ren_entry || !ren_entry->old_name || !ren_entry->new_name) {
-+ printk(KERN_CRIT "mini_fo: meta_list_add_r_entry: \
-+ out of mem.\n");
-+ kfree(ren_entry->new_name);
-+ kfree(ren_entry->old_name);
-+ kfree(ren_entry);
-+ return -ENOMEM;
-+ }
-+
-+ strncpy(ren_entry->old_name, old_name, old_len);
-+ ren_entry->old_len = old_len;
-+ strncpy(ren_entry->new_name, new_name, new_len);
-+ ren_entry->new_len = new_len;
-+
-+ list_add(&ren_entry->list, &inode_info->renamed_list);
-+ inode_info->renamed_list_size++;
-+ return 0;
-+}
-+
-+
-+int meta_remove_r_entry(dentry_t *dentry, const char *name, int len)
-+{
-+ int err = 0;
-+ if(!dentry || !dentry->d_inode) {
-+ printk(KERN_CRIT
-+ "mini_fo: meta_remove_r_entry: \
-+ invalid dentry passed.\n");
-+ return -1;
-+ }
-+
-+ err = meta_list_remove_r_entry(dentry, name, len);
-+ err |= meta_sync_lists(dentry);
-+ return err;
-+}
-+
-+int meta_list_remove_r_entry(dentry_t *dentry, const char *name, int len)
-+{
-+ if(!dentry || !dentry->d_inode) {
-+ printk(KERN_CRIT
-+ "mini_fo: meta_list_remove_r_entry: \
-+ invalid dentry passed.\n");
-+ return -1;
-+ }
-+ return __meta_list_remove_r_entry(dentry->d_inode, name, len);
-+}
-+
-+int __meta_list_remove_r_entry(inode_t *inode, const char *name, int len)
-+{
-+ struct list_head *tmp;
-+ struct renamed_entry *ren_entry;
-+ struct mini_fo_inode_info *inode_info;
-+
-+ if(!inode || !itopd(inode))
-+ printk(KERN_CRIT
-+ "mini_fo: __meta_list_remove_r_entry: \
-+ invalid inode passed.\n");
-+ inode_info = itopd(inode);
-+
-+ if(inode_info->renamed_list_size < 0)
-+ return -1;
-+ if(inode_info->renamed_list_size == 0)
-+ return 1;
-+
-+ list_for_each(tmp, &inode_info->renamed_list) {
-+ ren_entry = list_entry(tmp, struct renamed_entry, list);
-+ if(ren_entry->new_len != len)
-+ continue;
-+
-+ if(!strncmp(ren_entry->new_name, name, len)) {
-+ list_del(tmp);
-+ kfree(ren_entry->new_name);
-+ kfree(ren_entry->old_name);
-+ kfree(ren_entry);
-+ inode_info->renamed_list_size--;
-+ return 0;
-+ }
-+ }
-+ return 1;
-+}
-+
-+
-+/* append a single D entry to the meta file */
-+int meta_write_d_entry(dentry_t *dentry, const char *name, int len)
-+{
-+ dentry_t *meta_dentry = 0;
-+ file_t *meta_file = 0;
-+ mm_segment_t old_fs;
-+
-+ int bytes, err;
-+ struct vfsmount *meta_mnt = 0;
-+ char *buf;
-+
-+ err = 0;
-+
-+ if(itopd(dentry->d_inode)->deleted_list_size < 0) {
-+ err = -1;
-+ goto out;
-+ }
-+
-+ if(dtopd(dentry)->state == UNMODIFIED) {
-+ err = build_sto_structure(dentry->d_parent, dentry);
-+ if(err) {
-+ printk(KERN_CRIT "mini_fo: meta_write_d_entry: \
-+ build_sto_structure failed.\n");
-+ goto out;
-+ }
-+ }
-+ meta_dentry = lookup_one_len(META_FILENAME,
-+ dtohd2(dentry), strlen (META_FILENAME));
-+
-+ /* We need to create a META-file */
-+ if(!meta_dentry->d_inode) {
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ vfs_create(dtohd2(dentry)->d_inode,
-+ meta_dentry,
-+ S_IRUSR | S_IWUSR,
-+ NULL);
-+#else
-+ vfs_create(dtohd2(dentry)->d_inode,
-+ meta_dentry,
-+ S_IRUSR | S_IWUSR);
-+#endif
-+ }
-+ /* open META-file for writing */
-+ meta_file = dentry_open(meta_dentry, meta_mnt, 0x1);
-+ if(!meta_file || IS_ERR(meta_file)) {
-+ printk(KERN_CRIT "mini_fo: meta_write_d_entry: \
-+ ERROR opening meta file.\n");
-+ mntput(meta_mnt); /* $%& is this necessary? */
-+ dput(meta_dentry);
-+ err = -1;
-+ goto out;
-+ }
-+
-+ /* check if fs supports writing */
-+ if(!meta_file->f_op->write) {
-+ printk(KERN_CRIT "mini_fo: meta_write_d_entry: \
-+ ERROR, fs does not support writing.\n");
-+ goto out_err_close;
-+ }
-+
-+ meta_file->f_pos = meta_dentry->d_inode->i_size; /* append */
-+ old_fs = get_fs();
-+ set_fs(KERNEL_DS);
-+
-+ /* size: len for name, 1 for \n and 2 for "D " */
-+ buf = (char *) kmalloc(len+3, GFP_KERNEL);
-+ if (!buf) {
-+ printk(KERN_CRIT "mini_fo: meta_write_d_entry: \
-+ out of mem.\n");
-+ return -ENOMEM;
-+ }
-+
-+ buf[0] = 'D';
-+ buf[1] = ' ';
-+ strncpy(buf+2, name, len);
-+ buf[len+2] = '\n';
-+ bytes = meta_file->f_op->write(meta_file, buf, len+3,
-+ &meta_file->f_pos);
-+ if(bytes != len+3) {
-+ printk(KERN_CRIT "mini_fo: meta_write_d_entry: \
-+ ERROR writing.\n");
-+ err = -1;
-+ }
-+ kfree(buf);
-+ set_fs(old_fs);
-+
-+ out_err_close:
-+ fput(meta_file);
-+ out:
-+ return err;
-+}
-+
-+/* append a single R entry to the meta file */
-+int meta_write_r_entry(dentry_t *dentry,
-+ const char *old_name, int old_len,
-+ const char *new_name, int new_len)
-+{
-+ dentry_t *meta_dentry = 0;
-+ file_t *meta_file = 0;
-+ mm_segment_t old_fs;
-+
-+ int bytes, err, buf_len;
-+ struct vfsmount *meta_mnt = 0;
-+ char *buf;
-+
-+
-+ err = 0;
-+
-+ if(itopd(dentry->d_inode)->renamed_list_size < 0) {
-+ err = -1;
-+ goto out;
-+ }
-+
-+ /* build the storage structure? */
-+ if(dtopd(dentry)->state == UNMODIFIED) {
-+ err = build_sto_structure(dentry->d_parent, dentry);
-+ if(err) {
-+ printk(KERN_CRIT "mini_fo: meta_write_r_entry: \
-+ build_sto_structure failed.\n");
-+ goto out;
-+ }
-+ }
-+ meta_dentry = lookup_one_len(META_FILENAME,
-+ dtohd2(dentry),
-+ strlen (META_FILENAME));
-+ if(!meta_dentry->d_inode) {
-+ /* We need to create a META-file */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ vfs_create(dtohd2(dentry)->d_inode,
-+ meta_dentry, S_IRUSR | S_IWUSR, NULL);
-+#else
-+ vfs_create(dtohd2(dentry)->d_inode,
-+ meta_dentry, S_IRUSR | S_IWUSR);
-+#endif
-+ }
-+ /* open META-file for writing */
-+ meta_file = dentry_open(meta_dentry, meta_mnt, 0x1);
-+ if(!meta_file || IS_ERR(meta_file)) {
-+ printk(KERN_CRIT "mini_fo: meta_write_r_entry: \
-+ ERROR opening meta file.\n");
-+ mntput(meta_mnt);
-+ dput(meta_dentry);
-+ err = -1;
-+ goto out;
-+ }
-+
-+ /* check if fs supports writing */
-+ if(!meta_file->f_op->write) {
-+ printk(KERN_CRIT "mini_fo: meta_write_r_entry: \
-+ ERROR, fs does not support writing.\n");
-+ goto out_err_close;
-+ }
-+
-+ meta_file->f_pos = meta_dentry->d_inode->i_size; /* append */
-+ old_fs = get_fs();
-+ set_fs(KERNEL_DS);
-+
-+ /* size: 2 for "R ", old_len+new_len for names, 1 blank+1 \n */
-+ buf_len = old_len + new_len + 4;
-+ buf = (char *) kmalloc(buf_len, GFP_KERNEL);
-+ if (!buf) {
-+ printk(KERN_CRIT "mini_fo: meta_write_r_entry: out of mem.\n");
-+ return -ENOMEM;
-+ }
-+
-+ buf[0] = 'R';
-+ buf[1] = ' ';
-+ strncpy(buf + 2, old_name, old_len);
-+ buf[old_len + 2] = ' ';
-+ strncpy(buf + old_len + 3, new_name, new_len);
-+ buf[buf_len -1] = '\n';
-+ bytes = meta_file->f_op->write(meta_file, buf, buf_len, &meta_file->f_pos);
-+ if(bytes != buf_len) {
-+ printk(KERN_CRIT "mini_fo: meta_write_r_entry: ERROR writing.\n");
-+ err = -1;
-+ }
-+
-+ kfree(buf);
-+ set_fs(old_fs);
-+
-+ out_err_close:
-+ fput(meta_file);
-+ out:
-+ return err;
-+}
-+
-+/* sync D list to disk, append data if app_flag is 1 */
-+/* check the meta_mnt, which seems not to be used (properly) */
-+
-+int meta_sync_d_list(dentry_t *dentry, int app_flag)
-+{
-+ dentry_t *meta_dentry;
-+ file_t *meta_file;
-+ mm_segment_t old_fs;
-+
-+ int bytes, err;
-+ struct vfsmount *meta_mnt;
-+ char *buf;
-+
-+ struct list_head *tmp;
-+ struct deleted_entry *del_entry;
-+ struct mini_fo_inode_info *inode_info;
-+
-+ err = 0;
-+ meta_file=0;
-+ meta_mnt=0;
-+
-+ if(!dentry || !dentry->d_inode) {
-+ printk(KERN_CRIT "mini_fo: meta_sync_d_list: \
-+ invalid inode passed.\n");
-+ err = -1;
-+ goto out;
-+ }
-+ inode_info = itopd(dentry->d_inode);
-+
-+ if(inode_info->deleted_list_size < 0) {
-+ err = -1;
-+ goto out;
-+ }
-+
-+ /* ok, there is something to sync */
-+
-+ /* build the storage structure? */
-+ if(!dtohd2(dentry) && !itohi2(dentry->d_inode)) {
-+ err = build_sto_structure(dentry->d_parent, dentry);
-+ if(err) {
-+ printk(KERN_CRIT "mini_fo: meta_sync_d_list: \
-+ build_sto_structure failed.\n");
-+ goto out;
-+ }
-+ }
-+ meta_dentry = lookup_one_len(META_FILENAME,
-+ dtohd2(dentry),
-+ strlen(META_FILENAME));
-+ if(!meta_dentry->d_inode) {
-+ /* We need to create a META-file */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ vfs_create(dtohd2(dentry)->d_inode,
-+ meta_dentry, S_IRUSR | S_IWUSR, NULL);
-+#else
-+ vfs_create(dtohd2(dentry)->d_inode,
-+ meta_dentry, S_IRUSR | S_IWUSR);
-+#endif
-+ app_flag = 0;
-+ }
-+ /* need we truncate the meta file? */
-+ if(!app_flag) {
-+ struct iattr newattrs;
-+ newattrs.ia_size = 0;
-+ newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&meta_dentry->d_inode->i_mutex);
-+#else
-+ down(&meta_dentry->d_inode->i_sem);
-+#endif
-+ err = notify_change(meta_dentry, &newattrs);
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&meta_dentry->d_inode->i_mutex);
-+#else
-+ up(&meta_dentry->d_inode->i_sem);
-+#endif
-+
-+ if(err || meta_dentry->d_inode->i_size != 0) {
-+ printk(KERN_CRIT "mini_fo: meta_sync_d_list: \
-+ ERROR truncating meta file.\n");
-+ goto out_err_close;
-+ }
-+ }
-+
-+ /* open META-file for writing */
-+ meta_file = dentry_open(meta_dentry, meta_mnt, 0x1);
-+ if(!meta_file || IS_ERR(meta_file)) {
-+ printk(KERN_CRIT "mini_fo: meta_sync_d_list: \
-+ ERROR opening meta file.\n");
-+ /* we don't mntget so we dont't mntput (for now)
-+ * mntput(meta_mnt);
-+ */
-+ dput(meta_dentry);
-+ err = -1;
-+ goto out;
-+ }
-+
-+ /* check if fs supports writing */
-+ if(!meta_file->f_op->write) {
-+ printk(KERN_CRIT "mini_fo: meta_sync_d_list: \
-+ ERROR, fs does not support writing.\n");
-+ goto out_err_close;
-+ }
-+
-+ meta_file->f_pos = meta_dentry->d_inode->i_size; /* append */
-+ old_fs = get_fs();
-+ set_fs(KERNEL_DS);
-+
-+ /* here we go... */
-+ list_for_each(tmp, &inode_info->deleted_list) {
-+ del_entry = list_entry(tmp, struct deleted_entry, list);
-+
-+ /* size: len for name, 1 for \n and 2 for "D " */
-+ buf = (char *) kmalloc(del_entry->len+3, GFP_KERNEL);
-+ if (!buf) {
-+ printk(KERN_CRIT "mini_fo: meta_sync_d_list: \
-+ out of mem.\n");
-+ return -ENOMEM;
-+ }
-+
-+ buf[0] = 'D';
-+ buf[1] = ' ';
-+ strncpy(buf+2, del_entry->name, del_entry->len);
-+ buf[del_entry->len+2] = '\n';
-+ bytes = meta_file->f_op->write(meta_file, buf,
-+ del_entry->len+3,
-+ &meta_file->f_pos);
-+ if(bytes != del_entry->len+3) {
-+ printk(KERN_CRIT "mini_fo: meta_sync_d_list: \
-+ ERROR writing.\n");
-+ err |= -1;
-+ }
-+ kfree(buf);
-+ }
-+ set_fs(old_fs);
-+
-+ out_err_close:
-+ fput(meta_file);
-+ out:
-+ return err;
-+
-+}
-+
-+int meta_sync_r_list(dentry_t *dentry, int app_flag)
-+{
-+ dentry_t *meta_dentry;
-+ file_t *meta_file;
-+ mm_segment_t old_fs;
-+
-+ int bytes, err, buf_len;
-+ struct vfsmount *meta_mnt;
-+ char *buf;
-+
-+ struct list_head *tmp;
-+ struct renamed_entry *ren_entry;
-+ struct mini_fo_inode_info *inode_info;
-+
-+ err = 0;
-+ meta_file=0;
-+ meta_mnt=0;
-+
-+ if(!dentry || !dentry->d_inode) {
-+ printk(KERN_CRIT "mini_fo: meta_sync_r_list: \
-+ invalid dentry passed.\n");
-+ err = -1;
-+ goto out;
-+ }
-+ inode_info = itopd(dentry->d_inode);
-+
-+ if(inode_info->deleted_list_size < 0) {
-+ err = -1;
-+ goto out;
-+ }
-+
-+ /* ok, there is something to sync */
-+
-+ /* build the storage structure? */
-+ if(!dtohd2(dentry) && !itohi2(dentry->d_inode)) {
-+ err = build_sto_structure(dentry->d_parent, dentry);
-+ if(err) {
-+ printk(KERN_CRIT "mini_fo: meta_sync_r_list: \
-+ build_sto_structure failed.\n");
-+ goto out;
-+ }
-+ }
-+ meta_dentry = lookup_one_len(META_FILENAME,
-+ dtohd2(dentry),
-+ strlen(META_FILENAME));
-+ if(!meta_dentry->d_inode) {
-+ /* We need to create a META-file */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ vfs_create(dtohd2(dentry)->d_inode,
-+ meta_dentry, S_IRUSR | S_IWUSR, NULL);
-+#else
-+ vfs_create(dtohd2(dentry)->d_inode,
-+ meta_dentry, S_IRUSR | S_IWUSR);
-+#endif
-+ app_flag = 0;
-+ }
-+ /* need we truncate the meta file? */
-+ if(!app_flag) {
-+ struct iattr newattrs;
-+ newattrs.ia_size = 0;
-+ newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&meta_dentry->d_inode->i_mutex);
-+#else
-+ down(&meta_dentry->d_inode->i_sem);
-+#endif
-+ err = notify_change(meta_dentry, &newattrs);
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&meta_dentry->d_inode->i_mutex);
-+#else
-+ up(&meta_dentry->d_inode->i_sem);
-+#endif
-+ if(err || meta_dentry->d_inode->i_size != 0) {
-+ printk(KERN_CRIT "mini_fo: meta_sync_r_list: \
-+ ERROR truncating meta file.\n");
-+ goto out_err_close;
-+ }
-+ }
-+
-+ /* open META-file for writing */
-+ meta_file = dentry_open(meta_dentry, meta_mnt, 0x1);
-+ if(!meta_file || IS_ERR(meta_file)) {
-+ printk(KERN_CRIT "mini_fo: meta_sync_r_list: \
-+ ERROR opening meta file.\n");
-+ /* we don't mntget so we dont't mntput (for now)
-+ * mntput(meta_mnt);
-+ */
-+ dput(meta_dentry);
-+ err = -1;
-+ goto out;
-+ }
-+
-+ /* check if fs supports writing */
-+ if(!meta_file->f_op->write) {
-+ printk(KERN_CRIT "mini_fo: meta_sync_r_list: \
-+ ERROR, fs does not support writing.\n");
-+ goto out_err_close;
-+ }
-+
-+ meta_file->f_pos = meta_dentry->d_inode->i_size; /* append */
-+ old_fs = get_fs();
-+ set_fs(KERNEL_DS);
-+
-+ /* here we go... */
-+ list_for_each(tmp, &inode_info->renamed_list) {
-+ ren_entry = list_entry(tmp, struct renamed_entry, list);
-+ /* size:
-+ * 2 for "R ", old_len+new_len for names, 1 blank+1 \n */
-+ buf_len = ren_entry->old_len + ren_entry->new_len + 4;
-+ buf = (char *) kmalloc(buf_len, GFP_KERNEL);
-+ if (!buf) {
-+ printk(KERN_CRIT "mini_fo: meta_sync_r_list: \
-+ out of mem.\n");
-+ return -ENOMEM;
-+ }
-+ buf[0] = 'R';
-+ buf[1] = ' ';
-+ strncpy(buf + 2, ren_entry->old_name, ren_entry->old_len);
-+ buf[ren_entry->old_len + 2] = ' ';
-+ strncpy(buf + ren_entry->old_len + 3,
-+ ren_entry->new_name, ren_entry->new_len);
-+ buf[buf_len - 1] = '\n';
-+ bytes = meta_file->f_op->write(meta_file, buf,
-+ buf_len, &meta_file->f_pos);
-+ if(bytes != buf_len) {
-+ printk(KERN_CRIT "mini_fo: meta_sync_r_list: \
-+ ERROR writing.\n");
-+ err |= -1;
-+ }
-+ kfree(buf);
-+ }
-+ set_fs(old_fs);
-+
-+ out_err_close:
-+ fput(meta_file);
-+ out:
-+ return err;
-+}
-+
-+int meta_check_d_entry(dentry_t *dentry, const char *name, int len)
-+{
-+ if(!dentry || !dentry->d_inode)
-+ printk(KERN_CRIT "mini_fo: meta_check_d_dentry: \
-+ invalid dentry passed.\n");
-+ return __meta_check_d_entry(dentry->d_inode, name, len);
-+}
-+
-+int __meta_check_d_entry(inode_t *inode, const char *name, int len)
-+{
-+ struct list_head *tmp;
-+ struct deleted_entry *del_entry;
-+ struct mini_fo_inode_info *inode_info;
-+
-+ if(!inode || !itopd(inode))
-+ printk(KERN_CRIT "mini_fo: __meta_check_d_dentry: \
-+ invalid inode passed.\n");
-+
-+ inode_info = itopd(inode);
-+
-+ if(inode_info->deleted_list_size <= 0)
-+ return 0;
-+
-+ list_for_each(tmp, &inode_info->deleted_list) {
-+ del_entry = list_entry(tmp, struct deleted_entry, list);
-+ if(del_entry->len != len)
-+ continue;
-+
-+ if(!strncmp(del_entry->name, name, len))
-+ return 1;
-+ }
-+ return 0;
-+}
-+
-+/*
-+ * check if file has been renamed and return path to orig. base dir.
-+ * Implements no error return values so far, what of course sucks.
-+ * String is null terminated.'
-+ */
-+char* meta_check_r_entry(dentry_t *dentry, const char *name, int len)
-+{
-+ if(!dentry || !dentry->d_inode) {
-+ printk(KERN_CRIT "mini_fo: meta_check_r_dentry: \
-+ invalid dentry passed.\n");
-+ return NULL;
-+ }
-+ return __meta_check_r_entry(dentry->d_inode, name, len);
-+}
-+
-+char* __meta_check_r_entry(inode_t *inode, const char *name, int len)
-+{
-+ struct list_head *tmp;
-+ struct renamed_entry *ren_entry;
-+ struct mini_fo_inode_info *inode_info;
-+ char *old_path;
-+
-+ if(!inode || !itopd(inode)) {
-+ printk(KERN_CRIT "mini_fo: meta_check_r_dentry: \
-+ invalid inode passed.\n");
-+ return NULL;
-+ }
-+ inode_info = itopd(inode);
-+
-+ if(inode_info->renamed_list_size <= 0)
-+ return NULL;
-+
-+ list_for_each(tmp, &inode_info->renamed_list) {
-+ ren_entry = list_entry(tmp, struct renamed_entry, list);
-+ if(ren_entry->new_len != len)
-+ continue;
-+
-+ if(!strncmp(ren_entry->new_name, name, len)) {
-+ old_path = (char *)
-+ kmalloc(ren_entry->old_len+1, GFP_KERNEL);
-+ strncpy(old_path,
-+ ren_entry->old_name,
-+ ren_entry->old_len);
-+ old_path[ren_entry->old_len]='\0';
-+ return old_path;
-+ }
-+ }
-+ return NULL;
-+}
-+
-+/*
-+ * This version only checks if entry exists and return:
-+ * 1 if exists,
-+ * 0 if not,
-+ * -1 if error.
-+ */
-+int meta_is_r_entry(dentry_t *dentry, const char *name, int len)
-+{
-+ if(!dentry || !dentry->d_inode) {
-+ printk(KERN_CRIT "mini_fo: meta_check_r_dentry [2]: \
-+ invalid dentry passed.\n");
-+ return -1;
-+ }
-+ return __meta_is_r_entry(dentry->d_inode, name, len);
-+}
-+
-+int __meta_is_r_entry(inode_t *inode, const char *name, int len)
-+{
-+ struct list_head *tmp;
-+ struct renamed_entry *ren_entry;
-+ struct mini_fo_inode_info *inode_info;
-+
-+ if(!inode || !itopd(inode)) {
-+ printk(KERN_CRIT "mini_fo: meta_check_r_dentry [2]: \
-+ invalid inode passed.\n");
-+ return -1;
-+ }
-+ inode_info = itopd(inode);
-+
-+ if(inode_info->renamed_list_size <= 0)
-+ return -1;
-+
-+ list_for_each(tmp, &inode_info->renamed_list) {
-+ ren_entry = list_entry(tmp, struct renamed_entry, list);
-+ if(ren_entry->new_len != len)
-+ continue;
-+
-+ if(!strncmp(ren_entry->new_name, name, len))
-+ return 1;
-+ }
-+ return 0;
-+}
-+
---- /dev/null
-+++ b/fs/mini_fo/mini_fo.h
-@@ -0,0 +1,510 @@
-+/*
-+ * Copyright (c) 1997-2003 Erez Zadok
-+ * Copyright (c) 2001-2003 Stony Brook University
-+ *
-+ * For specific licensing information, see the COPYING file distributed with
-+ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
-+ *
-+ * This Copyright notice must be kept intact and distributed with all
-+ * fistgen sources INCLUDING sources generated by fistgen.
-+ */
-+/*
-+ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
-+ *
-+ * This program is free software; you can redistribute it and/or
-+ * modify it under the terms of the GNU General Public License
-+ * as published by the Free Software Foundation; either version
-+ * 2 of the License, or (at your option) any later version.
-+ */
-+
-+/*
-+ * $Id$
-+ */
-+
-+#ifndef __MINI_FO_H_
-+#define __MINI_FO_H_
-+
-+#ifdef __KERNEL__
-+
-+/* META stuff */
-+#define META_FILENAME "META_dAfFgHE39ktF3HD2sr"
-+
-+/* use xattrs? */
-+#define XATTR
-+
-+/* File attributes that when changed, result in a file beeing copied to storage */
-+#define COPY_FLAGS ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_SIZE
-+
-+/*
-+ * mini_fo filestates
-+ */
-+#define MODIFIED 1
-+#define UNMODIFIED 2
-+#define CREATED 3
-+#define DEL_REWRITTEN 4
-+#define DELETED 5
-+#define NON_EXISTANT 6
-+
-+/* fist file systems superblock magic */
-+# define MINI_FO_SUPER_MAGIC 0xf15f
-+
-+/*
-+ * STRUCTURES:
-+ */
-+
-+/* mini_fo inode data in memory */
-+struct mini_fo_inode_info {
-+ inode_t *wii_inode;
-+ inode_t *wii_inode2; /* pointer to storage inode */
-+
-+ /* META-data lists */
-+ /* deleted list, ex wol */
-+ struct list_head deleted_list;
-+ int deleted_list_size;
-+
-+ /* renamed list */
-+ struct list_head renamed_list;
-+ int renamed_list_size;
-+
-+ /* add other lists here ... */
-+};
-+
-+/* mini_fo dentry data in memory */
-+struct mini_fo_dentry_info {
-+ dentry_t *wdi_dentry;
-+ dentry_t *wdi_dentry2; /* pointer to storage dentry */
-+ unsigned int state; /* state of the mini_fo dentry */
-+};
-+
-+
-+/* mini_fo super-block data in memory */
-+struct mini_fo_sb_info {
-+ super_block_t *wsi_sb, *wsi_sb2; /* mk: might point to the same sb */
-+ struct vfsmount *hidden_mnt, *hidden_mnt2;
-+ dentry_t *base_dir_dentry;
-+ dentry_t *storage_dir_dentry;
-+ ;
-+};
-+
-+/* readdir_data, readdir helper struct */
-+struct readdir_data {
-+ struct list_head ndl_list; /* linked list head ptr */
-+ int ndl_size; /* list size */
-+ int sto_done; /* flag to show that the storage dir entries have
-+ * all been read an now follow base entries */
-+};
-+
-+/* file private data. */
-+struct mini_fo_file_info {
-+ struct file *wfi_file;
-+ struct file *wfi_file2; /* pointer to storage file */
-+ struct readdir_data rd;
-+};
-+
-+/* struct ndl_entry */
-+struct ndl_entry {
-+ struct list_head list;
-+ char *name;
-+ int len;
-+};
-+
-+/********************************
-+ * META-data structures
-+ ********************************/
-+
-+/* deleted entry */
-+struct deleted_entry {
-+ struct list_head list;
-+ char *name;
-+ int len;
-+};
-+
-+/* renamed entry */
-+struct renamed_entry {
-+ struct list_head list;
-+ char *old_name; /* old directory with full path */
-+ int old_len; /* length of above string */
-+ char *new_name; /* new directory name */
-+ int new_len; /* length of above string */
-+};
-+
-+/* attr_change entry */
-+struct attr_change_entry {
-+ struct list_head list;
-+ char *name;
-+ int len;
-+};
-+
-+/* link entry */
-+struct link_entry {
-+ struct list_head list;
-+ int links_moved;
-+ int inum_base;
-+ int inum_sto;
-+ char *weird_name;
-+ int weird_name_len;
-+};
-+
-+
-+/* Some other stuff required for mini_fo_filldir64, copied from
-+ * fs/readdir.c
-+ */
-+
-+#define ROUND_UP64(x) (((x)+sizeof(u64)-1) & ~(sizeof(u64)-1))
-+#define NAME_OFFSET(de) ((int) ((de)->d_name - (char *) (de)))
-+
-+
-+struct linux_dirent64 {
-+ u64 d_ino;
-+ s64 d_off;
-+ unsigned short d_reclen;
-+ unsigned char d_type;
-+ char d_name[0];
-+};
-+
-+
-+struct getdents_callback64 {
-+ struct linux_dirent64 * current_dir;
-+ struct linux_dirent64 * previous;
-+ int count;
-+ int error;
-+};
-+
-+struct linux_dirent {
-+ unsigned long d_ino;
-+ unsigned long d_off;
-+ unsigned short d_reclen;
-+ char d_name[1];
-+};
-+
-+struct getdents_callback {
-+ struct linux_dirent * current_dir;
-+ struct linux_dirent * previous;
-+ int count;
-+ int error;
-+};
-+
-+
-+/*
-+ * MACROS:
-+ */
-+
-+/* file TO private_data */
-+# define ftopd(file) ((struct mini_fo_file_info *)((file)->private_data))
-+# define __ftopd(file) ((file)->private_data)
-+/* file TO hidden_file */
-+# define ftohf(file) ((ftopd(file))->wfi_file)
-+# define ftohf2(file) ((ftopd(file))->wfi_file2)
-+
-+/* inode TO private_data */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
-+# define itopd(ino) ((struct mini_fo_inode_info *)(ino)->i_private)
-+# define __itopd(ino) ((ino)->i_private)
-+#else
-+# define itopd(ino) ((struct mini_fo_inode_info *)(ino)->u.generic_ip)
-+# define __itopd(ino) ((ino)->u.generic_ip)
-+#endif
-+/* inode TO hidden_inode */
-+# define itohi(ino) (itopd(ino)->wii_inode)
-+# define itohi2(ino) (itopd(ino)->wii_inode2)
-+
-+/* superblock TO private_data */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+# define stopd(super) ((struct mini_fo_sb_info *)(super)->s_fs_info)
-+# define __stopd(super) ((super)->s_fs_info)
-+#else
-+# define stopd(super) ((struct mini_fo_sb_info *)(super)->u.generic_sbp)
-+# define __stopd(super) ((super)->u.generic_sbp)
-+#endif
-+
-+/* unused? # define vfs2priv stopd */
-+/* superblock TO hidden_superblock */
-+
-+# define stohs(super) (stopd(super)->wsi_sb)
-+# define stohs2(super) (stopd(super)->wsi_sb2)
-+
-+/* dentry TO private_data */
-+# define dtopd(dentry) ((struct mini_fo_dentry_info *)(dentry)->d_fsdata)
-+# define __dtopd(dentry) ((dentry)->d_fsdata)
-+/* dentry TO hidden_dentry */
-+# define dtohd(dent) (dtopd(dent)->wdi_dentry)
-+# define dtohd2(dent) (dtopd(dent)->wdi_dentry2)
-+
-+/* dentry to state */
-+# define dtost(dent) (dtopd(dent)->state)
-+# define sbt(sb) ((sb)->s_type->name)
-+
-+#define IS_WRITE_FLAG(flag) (flag & (O_RDWR | O_WRONLY | O_APPEND))
-+#define IS_COPY_FLAG(flag) (flag & (COPY_FLAGS))
-+
-+/* macros to simplify non-SCA code */
-+# define MALLOC_PAGE_POINTERS(hidden_pages, num_hidden_pages)
-+# define MALLOC_PAGEDATA_POINTERS(hidden_pages_data, num_hidden_pages)
-+# define FREE_PAGE_POINTERS(hidden_pages, num)
-+# define FREE_PAGEDATA_POINTERS(hidden_pages_data, num)
-+# define FOR_EACH_PAGE
-+# define CURRENT_HIDDEN_PAGE hidden_page
-+# define CURRENT_HIDDEN_PAGEDATA hidden_page_data
-+# define CURRENT_HIDDEN_PAGEINDEX page->index
-+
-+/*
-+ * EXTERNALS:
-+ */
-+extern struct file_operations mini_fo_main_fops;
-+extern struct file_operations mini_fo_dir_fops;
-+extern struct inode_operations mini_fo_main_iops;
-+extern struct inode_operations mini_fo_dir_iops;
-+extern struct inode_operations mini_fo_symlink_iops;
-+extern struct super_operations mini_fo_sops;
-+extern struct dentry_operations mini_fo_dops;
-+extern struct vm_operations_struct mini_fo_shared_vmops;
-+extern struct vm_operations_struct mini_fo_private_vmops;
-+extern struct address_space_operations mini_fo_aops;
-+
-+#if 0 /* unused by mini_fo */
-+extern int mini_fo_interpose(dentry_t *hidden_dentry, dentry_t *this_dentry, super_block_t *sb, int flag);
-+#if defined(FIST_FILTER_DATA) || defined(FIST_FILTER_SCA)
-+extern page_t *mini_fo_get1page(file_t *file, int index);
-+extern int mini_fo_fill_zeros(file_t *file, page_t *page, unsigned from);
-+# endif /* FIST_FILTER_DATA || FIST_FILTER_SCA */
-+
-+
-+# define mini_fo_hidden_dentry(d) __mini_fo_hidden_dentry(__FILE__,__FUNCTION__,__LINE__,(d))
-+# define mini_fo_hidden_sto_dentry(d) __mini_fo_hidden_sto_dentry(__FILE__,__FUNCTION__,__LINE__,(d))
-+
-+extern dentry_t *__mini_fo_hidden_dentry(char *file, char *func, int line, dentry_t *this_dentry);
-+extern dentry_t *__mini_fo_hidden_sto_dentry(char *file, char *func, int line, dentry_t *this_dentry);
-+
-+extern int mini_fo_read_file(const char *filename, void *buf, int len);
-+extern int mini_fo_write_file(const char *filename, void *buf, int len);
-+extern dentry_t *fist_lookup(dentry_t *dir, const char *name, vnode_t **out, uid_t uid, gid_t gid);
-+#endif /* unused by mini_fo */
-+
-+/* state transition functions */
-+extern int nondir_unmod_to_mod(dentry_t *dentry, int cp_flag);
-+extern int nondir_del_rew_to_del(dentry_t *dentry);
-+extern int nondir_creat_to_del(dentry_t *dentry);
-+extern int nondir_mod_to_del(dentry_t *dentry);
-+extern int nondir_unmod_to_del(dentry_t *dentry);
-+
-+extern int dir_unmod_to_mod(dentry_t *dentry);
-+
-+/* rename specials */
-+extern int rename_directory(inode_t *old_dir, dentry_t *old_dentry, inode_t *new_dir, dentry_t *new_dentry);
-+extern int rename_nondir(inode_t *old_dir, dentry_t *old_dentry, inode_t *new_dir, dentry_t *new_dentry);
-+
-+/* misc stuff */
-+extern int mini_fo_tri_interpose(dentry_t *hidden_dentry,
-+ dentry_t *hidden_sto_dentry,
-+ dentry_t *dentry,
-+ super_block_t *sb, int flag);
-+
-+extern int mini_fo_cp_cont(dentry_t *tgt_dentry, struct vfsmount *tgt_mnt,
-+ dentry_t *src_dentry, struct vfsmount *src_mnt);
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+extern int mini_fo_create(inode_t *dir, dentry_t *dentry, int mode, struct nameidata *nd);
-+
-+extern int create_sto_nod(dentry_t *dentry, int mode, dev_t dev);
-+extern int create_sto_reg_file(dentry_t *dentry, int mode, struct nameidata *nd);
-+#else
-+extern int mini_fo_create(inode_t *dir, dentry_t *dentry, int mode);
-+
-+extern int create_sto_nod(dentry_t *dentry, int mode, int dev);
-+extern int create_sto_reg_file(dentry_t *dentry, int mode);
-+#endif
-+
-+extern int create_sto_dir(dentry_t *dentry, int mode);
-+
-+extern int exists_in_storage(dentry_t *dentry);
-+extern int is_mini_fo_existant(dentry_t *dentry);
-+extern int get_neg_sto_dentry(dentry_t *dentry);
-+extern int build_sto_structure(dentry_t *dir, dentry_t *dentry);
-+extern int get_mini_fo_bpath(dentry_t *dentry, char **bpath, int *bpath_len);
-+extern dentry_t *bpath_walk(super_block_t *sb, char *bpath);
-+extern int bpath_put(dentry_t *dentry);
-+
-+/* check_mini_fo types functions */
-+extern int check_mini_fo_dentry(dentry_t *dentry);
-+extern int check_mini_fo_file(file_t *file);
-+extern int check_mini_fo_inode(inode_t *inode);
-+
-+/* General meta functions, can be called from outside of meta.c */
-+extern int meta_build_lists(dentry_t *dentry);
-+extern int meta_put_lists(dentry_t *dentry);
-+extern int __meta_put_lists(inode_t *inode);
-+
-+extern int meta_add_d_entry(dentry_t *dentry, const char *name, int len);
-+extern int meta_add_r_entry(dentry_t *dentry,
-+ const char *old_name, int old_len,
-+ const char *new_name, int new_len);
-+
-+extern int meta_remove_r_entry(dentry_t *dentry, const char *name, int len);
-+
-+extern int meta_check_d_entry(dentry_t *dentry, const char *name, int len);
-+extern int __meta_check_d_entry(inode_t *inode, const char *name, int len);
-+
-+extern char* meta_check_r_entry(dentry_t *dentry, const char *name, int len);
-+extern char* __meta_check_r_entry(inode_t *inode, const char *name, int len);
-+extern int meta_is_r_entry(dentry_t *dentry, const char *name, int len);
-+extern int __meta_is_r_entry(inode_t *inode, const char *name, int len);
-+
-+/* Specific meta functions, should be called only inside meta.c */
-+extern int __meta_put_d_list(inode_t *inode);
-+extern int __meta_put_r_list(inode_t *inode);
-+
-+extern int meta_list_add_d_entry(dentry_t *dentry,
-+ const char *name, int len);
-+extern int meta_list_add_r_entry(dentry_t *dentry,
-+ const char *old_name, int old_len,
-+ const char *new_name, int new_len);
-+
-+extern int meta_list_remove_r_entry(dentry_t *dentry,
-+ const char *name, int len);
-+
-+extern int __meta_list_remove_r_entry(inode_t *inode,
-+ const char *name, int len);
-+
-+extern int meta_write_d_entry(dentry_t *dentry, const char *name, int len);
-+extern int meta_write_r_entry(dentry_t *dentry,
-+ const char *old_name, int old_len,
-+ const char *new_name, int new_len);
-+
-+extern int meta_sync_lists(dentry_t *dentry);
-+extern int meta_sync_d_list(dentry_t *dentry, int app_flag);
-+extern int meta_sync_r_list(dentry_t *dentry, int app_flag);
-+
-+/* ndl stuff */
-+extern int ndl_add_entry(struct readdir_data *rd, const char *name, int len);
-+extern void ndl_put_list(struct readdir_data *rd);
-+extern int ndl_check_entry(struct readdir_data *rd,
-+ const char *name, int len);
-+
-+
-+# define copy_inode_size(dst, src) \
-+ dst->i_size = src->i_size; \
-+ dst->i_blocks = src->i_blocks;
-+
-+static inline void
-+fist_copy_attr_atime(inode_t *dest, const inode_t *src)
-+{
-+ ASSERT(dest != NULL);
-+ ASSERT(src != NULL);
-+ dest->i_atime = src->i_atime;
-+}
-+static inline void
-+fist_copy_attr_times(inode_t *dest, const inode_t *src)
-+{
-+ ASSERT(dest != NULL);
-+ ASSERT(src != NULL);
-+ dest->i_atime = src->i_atime;
-+ dest->i_mtime = src->i_mtime;
-+ dest->i_ctime = src->i_ctime;
-+}
-+static inline void
-+fist_copy_attr_timesizes(inode_t *dest, const inode_t *src)
-+{
-+ ASSERT(dest != NULL);
-+ ASSERT(src != NULL);
-+ dest->i_atime = src->i_atime;
-+ dest->i_mtime = src->i_mtime;
-+ dest->i_ctime = src->i_ctime;
-+ copy_inode_size(dest, src);
-+}
-+static inline void
-+fist_copy_attr_all(inode_t *dest, const inode_t *src)
-+{
-+ ASSERT(dest != NULL);
-+ ASSERT(src != NULL);
-+ dest->i_mode = src->i_mode;
-+ dest->i_nlink = src->i_nlink;
-+ dest->i_uid = src->i_uid;
-+ dest->i_gid = src->i_gid;
-+ dest->i_rdev = src->i_rdev;
-+ dest->i_atime = src->i_atime;
-+ dest->i_mtime = src->i_mtime;
-+ dest->i_ctime = src->i_ctime;
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
-+ dest->i_blksize = src->i_blksize;
-+#endif
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,12)
-+ dest->i_blkbits = src->i_blkbits;
-+# endif /* linux 2.4.12 and newer */
-+ copy_inode_size(dest, src);
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
-+ dest->i_attr_flags = src->i_attr_flags;
-+#else
-+ dest->i_flags = src->i_flags;
-+#endif
-+}
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+/* copied from linux/fs.h */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+static inline void double_lock(struct dentry *d1, struct dentry *d2)
-+{
-+ struct mutex *m1 = &d1->d_inode->i_mutex;
-+ struct mutex *m2 = &d2->d_inode->i_mutex;
-+ if (m1 != m2) {
-+ if ((unsigned long) m1 < (unsigned long) m2) {
-+ struct mutex *tmp = m2;
-+ m2 = m1; m1 = tmp;
-+ }
-+ mutex_lock(m1);
-+ }
-+ mutex_lock(m2);
-+}
-+
-+static inline void double_unlock(struct dentry *d1, struct dentry *d2)
-+{
-+ struct mutex *m1 = &d1->d_inode->i_mutex;
-+ struct mutex *m2 = &d2->d_inode->i_mutex;
-+ mutex_unlock(m1);
-+ if (m1 != m2)
-+ mutex_unlock(m2);
-+ dput(d1);
-+ dput(d2);
-+}
-+
-+#else
-+static inline void double_down(struct semaphore *s1, struct semaphore *s2)
-+{
-+ if (s1 != s2) {
-+ if ((unsigned long) s1 < (unsigned long) s2) {
-+ struct semaphore *tmp = s2;
-+ s2 = s1; s1 = tmp;
-+ }
-+ down(s1);
-+ }
-+ down(s2);
-+}
-+
-+static inline void double_up(struct semaphore *s1, struct semaphore *s2)
-+{
-+ up(s1);
-+ if (s1 != s2)
-+ up(s2);
-+}
-+
-+static inline void double_lock(struct dentry *d1, struct dentry *d2)
-+{
-+ double_down(&d1->d_inode->i_sem, &d2->d_inode->i_sem);
-+}
-+
-+static inline void double_unlock(struct dentry *d1, struct dentry *d2)
-+{
-+ double_up(&d1->d_inode->i_sem,&d2->d_inode->i_sem);
-+ dput(d1);
-+ dput(d2);
-+}
-+#endif /* if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16) */
-+#endif /* if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0) */
-+#endif /* __KERNEL__ */
-+
-+/*
-+ * Definitions for user and kernel code
-+ */
-+
-+/* ioctls */
-+
-+#endif /* not __MINI_FO_H_ */
---- /dev/null
-+++ b/fs/mini_fo/mini_fo-merge
-@@ -0,0 +1,180 @@
-+#!/bin/bash
-+#
-+# Copyright (C) 2005 Markus Klotzbuecher <mk@creamnet.de>
-+# This program is free software; you can redistribute it and/or
-+# modify it under the terms of the GNU General Public License
-+# as published by the Free Software Foundation; either version
-+# 2 of the License, or (at your option) any later version.
-+#
-+
-+BASE=
-+STO=
-+HELP=
-+DRYRUN=
-+VERBOSE=
-+TMP="/tmp/"
-+META_NAME="META_dAfFgHE39ktF3HD2sr"
-+SKIP_DEL_LIST="skip-delete-list.mini_fo-merge"
-+
-+COMMAND=
-+exec_command()
-+{
-+ if [ x$DRYRUN == "xset" ]; then
-+ echo " would run: $COMMAND"
-+ elif ! [ x$DRYRUN == "xset" ]; then
-+ if [ x$VERBOSE == "xset" ]; then
-+ echo " running: $COMMAND"
-+ fi
-+ eval $COMMAND
-+ fi
-+}
-+
-+usage()
-+{
-+cat <<EOF
-+
-+USAGE: $0 -b <base dir> -s <storage dir>
-+Version 0.1
-+
-+This script merges the contents of a mini_fo storage file system back
-+to the base file system.
-+
-+!!! Warning: This will modify the base filesystem and can destroy data
-+ if used wrongly.
-+
-+Options:
-+ -b <base dir>
-+ the directory of the base file system.
-+
-+ -s <storage dir>
-+ the directory of the storage file system.
-+
-+ -d dry run, will not change anything and print the commands that
-+ would be executed.
-+
-+ -t tmp dir for storing temporary file. default: $TMP
-+
-+ -v show what operations are performed.
-+
-+ -h displays this message.
-+
-+EOF
-+}
-+
-+# parse parameters
-+while getopts hdvt:b:s: OPTS
-+ do
-+ case $OPTS in
-+ h) HELP="set";;
-+ d) DRYRUN="set";;
-+ v) VERBOSE="set";;
-+ b) BASE="$OPTARG";;
-+ s) STO="$OPTARG";;
-+ t) TMP="$OPTARG";;
-+ ?) usage
-+ exit 1;;
-+ esac
-+done
-+
-+if [ "x$HELP" == "xset" ]; then
-+ usage
-+ exit -1
-+fi
-+
-+if ! [ -d "$BASE" ] || ! [ -d "$STO" ]; then
-+ echo -e "$0:\n Error, -s and/or -b argument missing. type $0 -h for help."
-+ exit -1;
-+fi
-+
-+# get full paths
-+pushd $STO; STO=`pwd`; popd
-+pushd $BASE; BASE=`pwd`; popd
-+TMP=${TMP%/}
-+
-+
-+cat<<EOF
-+###############################################################################
-+# mini_fo-merge
-+#
-+# base dir: $BASE
-+# storage dir: $STO
-+# meta filename: $META_NAME
-+# dry run: $DRYRUN
-+# verbose: $VERBOSE
-+# tmp files: $TMP
-+###############################################################################
-+
-+EOF
-+
-+rm $TMP/$SKIP_DEL_LIST
-+
-+# first process all renamed dirs
-+echo "Merging renamed directories..."
-+pushd $STO &> /dev/null
-+find . -name $META_NAME -type f -print0 | xargs -0 -e grep -e '^R ' | tr -s ':R' ' ' | while read ENTRY; do
-+ echo "entry: $ENTRY"
-+ META_FILE=`echo $ENTRY | cut -d ' ' -f 1`
-+ OLD_B_DIR=`echo $ENTRY | cut -d ' ' -f 2 | sed -e 's/\///'`
-+ NEW_NAME=`echo $ENTRY | cut -d ' ' -f 3`
-+ NEW_B_DIR=`echo $META_FILE | sed -e "s/$META_NAME/$NEW_NAME/" | sed -e 's/^\.\///'`
-+ echo "META_FILE: $META_FILE"
-+ echo "OLD_B_DIR: $OLD_B_DIR"
-+ echo "NEW_NAME: $NEW_NAME"
-+ echo "NEW_B_DIR: $NEW_B_DIR"
-+
-+ pushd $BASE &> /dev/null
-+ # remove an existing dir in storage
-+ COMMAND="rm -rf $NEW_B_DIR"; exec_command
-+ COMMAND="cp -R $OLD_B_DIR $NEW_B_DIR"; exec_command
-+ echo ""
-+ popd &> /dev/null
-+
-+ # remember this dir to exclude it from deleting later
-+ echo $NEW_B_DIR >> $TMP/$SKIP_DEL_LIST
-+done
-+
-+# delete all whiteouted files from base
-+echo -e "\nDeleting whiteout'ed files from base file system..."
-+find . -name $META_NAME -type f -print0 | xargs -0 -e grep -e '^D ' | sed -e 's/:D//' | while read ENTRY; do
-+ META_FILE=`echo $ENTRY | cut -d ' ' -f 1`
-+ DEL_NAME=`echo $ENTRY | cut -d ' ' -f 2`
-+ DEL_FILE=`echo $META_FILE | sed -e "s/$META_NAME/$DEL_NAME/" | sed -e 's/^\.\///'`
-+ grep -x $DEL_FILE $TMP/$SKIP_DEL_LIST &> /dev/null
-+ if [ $? -ne 0 ]; then
-+ pushd $BASE &> /dev/null
-+ COMMAND="rm -rf $DEL_FILE"; exec_command
-+ popd &> /dev/null
-+ else
-+ echo " excluding: $DEL_FILE as in skip-del-list."
-+ fi
-+done
-+
-+# create all dirs and update permissions
-+echo -e "\nSetting up directory structures in base file system..."
-+find . -type d | sed -e 's/^\.\///' | while read DIR; do
-+ PERMS=`stat -c %a $DIR`
-+ DIR_UID=`stat -c %u $DIR`
-+ DIR_GID=`stat -c %g $DIR`
-+ pushd $BASE &> /dev/null
-+ if ! [ -d $DIR ]; then
-+ COMMAND="mkdir -p $DIR"; exec_command
-+ fi
-+ COMMAND="chmod $PERMS $DIR"; exec_command
-+ COMMAND="chown $DIR_UID:$DIR_GID $DIR"; exec_command
-+ popd &> /dev/null
-+done
-+
-+# merge all non-directory files
-+echo -e "\nMerging all non-directory files...."
-+for i in b c p f l s; do
-+ find . -type $i | sed -e 's/^\.\///' | grep -v "$META_NAME" | while read FILE; do
-+ pushd $BASE #&> /dev/null
-+ COMMAND="cp -df $STO/$FILE $BASE/$FILE"; exec_command
-+ popd &> /dev/null
-+ done
-+done
-+popd &> /dev/null
-+
-+#rm $TMP/$SKIP_DEL_LIST
-+
-+echo "Done!"
---- /dev/null
-+++ b/fs/mini_fo/mini_fo-overlay
-@@ -0,0 +1,130 @@
-+#!/bin/bash
-+#
-+# Copyright (C) 2005 Markus Klotzbuecher <mk@creamnet.de>
-+# This program is free software; you can redistribute it and/or
-+# modify it under the terms of the GNU General Public License
-+# as published by the Free Software Foundation; either version
-+# 2 of the License, or (at your option) any later version.
-+#
-+
-+HELP=
-+SUFF=
-+MNTP=
-+MNT_DIR="/mnt"
-+STO=
-+STO_DIR="/tmp"
-+BASE=
-+
-+usage()
-+{
-+cat <<EOF
-+
-+Usage: $0 [-s suffix] [-d sto_dir_dir] [-m mount point] base_dir
-+Version 0.1
-+
-+This script overlays the given base directory using the mini_fo file
-+system. If only the base directory base_dir is given, $0
-+will use a storage directory called "sto-<base_dir_name>" in $STO_DIR,
-+and mount point "mini_fo-<base_dir_dir>" in $MNT_DIR.
-+
-+Options:
-+ -s <suffix>
-+ add given suffix to storage directory and the mount
-+ point. This is usefull for overlaying one base directory
-+ several times and avoiding conflicts with storage directory
-+ names and mount points.
-+
-+ -d <sto_dir_dir>
-+ change the directory in which the storage directory will be
-+ created (default is currently "$STO_DIR".
-+
-+ -m <mount point>
-+ use an alternative directory to create the mini_fo
-+ mountpoint (default is currently "$MNT_DIR".
-+
-+ -h displays this message.
-+
-+EOF
-+exit 1;
-+}
-+
-+while getopts hm:s:d: OPTS
-+ do
-+ case $OPTS in
-+ s) SUFF="$OPTARG";;
-+ d) STO_DIR="$OPTARG";;
-+ m) MNT_DIR="$OPTARG";;
-+ h) HELP="set";;
-+ ?) usage
-+ exit 1;;
-+ esac
-+done
-+shift $(($OPTIND - 1))
-+
-+BASE="$1"
-+
-+if [ "x$HELP" == "xset" ]; then
-+ usage
-+ exit -1
-+fi
-+
-+# fix suffix
-+if [ "x$SUFF" != "x" ]; then
-+ SUFF="-$SUFF"
-+fi
-+
-+# kill trailing slashes
-+MNT_DIR=${MNT_DIR%/}
-+STO_DIR=${STO_DIR%/}
-+BASE=${BASE%/}
-+
-+
-+if ! [ -d "$BASE" ]; then
-+ echo "invalid base dir $BASE, run $0 -h for help."
-+ exit -1
-+fi
-+
-+# check opts
-+if ! [ -d "$MNT_DIR" ]; then
-+ echo "invalid mount dir $MNT_DIR, run $0 -h for help."
-+ exit -1
-+fi
-+
-+if ! [ -d "$STO_DIR" ]; then
-+ echo "invalid sto_dir_dir $STO_DIR, run $0 -h for help."
-+ exit -1
-+fi
-+
-+MNTP="$MNT_DIR/mini_fo-`basename $BASE`$SUFF"
-+STO="$STO_DIR/sto-`basename $BASE`$SUFF"
-+
-+# create the mount point if it doesn't exist
-+mkdir -p $MNTP
-+if [ $? -ne 0 ]; then
-+ echo "Error, failed to create mount point $MNTP"
-+fi
-+
-+mkdir -p $STO
-+if [ $? -ne 0 ]; then
-+ echo "Error, failed to create storage dir $STO"
-+fi
-+
-+# check if fs is already mounted
-+mount | grep mini_fo | grep $MNTP &> /dev/null
-+if [ $? -eq 0 ]; then
-+ echo "Error, existing mini_fo mount at $MNTP."
-+ exit -1
-+fi
-+
-+mount | grep mini_fo | grep $STO &> /dev/null
-+if [ $? -eq 0 ]; then
-+ echo "Error, $STO seems to be used already."
-+ exit -1
-+fi
-+
-+# mount
-+mount -t mini_fo -o base=$BASE,sto=$STO $BASE $MNTP
-+
-+if [ $? -ne 0 ]; then
-+ echo "Error, mounting failed, maybe no permisson to mount?"
-+fi
---- /dev/null
-+++ b/fs/mini_fo/mmap.c
-@@ -0,0 +1,637 @@
-+/*
-+ * Copyright (c) 1997-2003 Erez Zadok
-+ * Copyright (c) 2001-2003 Stony Brook University
-+ *
-+ * For specific licensing information, see the COPYING file distributed with
-+ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
-+ *
-+ * This Copyright notice must be kept intact and distributed with all
-+ * fistgen sources INCLUDING sources generated by fistgen.
-+ */
-+/*
-+ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
-+ *
-+ * This program is free software; you can redistribute it and/or
-+ * modify it under the terms of the GNU General Public License
-+ * as published by the Free Software Foundation; either version
-+ * 2 of the License, or (at your option) any later version.
-+ */
-+
-+/*
-+ * $Id$
-+ */
-+
-+#ifdef HAVE_CONFIG_H
-+# include <config.h>
-+#endif /* HAVE_CONFIG_H */
-+
-+#include "fist.h"
-+#include "mini_fo.h"
-+
-+
-+#ifdef FIST_COUNT_WRITES
-+/* for counting writes in the middle vs. regular writes */
-+unsigned long count_writes = 0, count_writes_middle = 0;
-+#endif /* FIST_COUNT_WRITES */
-+
-+/* forward declaration of commit write and prepare write */
-+STATIC int mini_fo_commit_write(file_t *file, page_t *page, unsigned from, unsigned to);
-+STATIC int mini_fo_prepare_write(file_t *file, page_t *page, unsigned from, unsigned to);
-+
-+
-+/*
-+ * Function for handling creation of holes when lseek-ing past the
-+ * end of the file and then writing some data.
-+ */
-+int
-+mini_fo_fill_zeros(file_t* file, page_t *page, unsigned from)
-+{
-+ int err = 0;
-+ dentry_t *dentry = file->f_dentry;
-+ inode_t *inode = dentry->d_inode;
-+ page_t *tmp_page;
-+ int index;
-+
-+ print_entry_location();
-+
-+ for (index = inode->i_size >> PAGE_CACHE_SHIFT; index < page->index; index++) {
-+ tmp_page = mini_fo_get1page(file, index);
-+ if (IS_ERR(tmp_page)) {
-+ err = PTR_ERR(tmp_page);
-+ goto out;
-+ }
-+
-+ /*
-+ * zero out rest of the contents of the page between the appropriate
-+ * offsets.
-+ */
-+ memset((char*)page_address(tmp_page) + (inode->i_size & ~PAGE_CACHE_MASK), 0, PAGE_CACHE_SIZE - (inode->i_size & ~PAGE_CACHE_MASK));
-+
-+ if (! (err = mini_fo_prepare_write(file, tmp_page, 0, PAGE_CACHE_SIZE)))
-+ err = mini_fo_commit_write(file, tmp_page, 0, PAGE_CACHE_SIZE);
-+
-+ page_cache_release(tmp_page);
-+ if (err < 0)
-+ goto out;
-+ if (current->need_resched)
-+ schedule();
-+ }
-+
-+ /* zero out appropriate parts of last page */
-+
-+ /*
-+ * if the encoding type is block, then adjust the 'from' (where the
-+ * zeroing will start) offset appropriately
-+ */
-+ from = from & (~(FIST_ENCODING_BLOCKSIZE - 1));
-+
-+ if ((from - (inode->i_size & ~PAGE_CACHE_MASK)) > 0) {
-+
-+ memset((char*)page_address(page) + (inode->i_size & ~PAGE_CACHE_MASK), 0, from - (inode->i_size & ~PAGE_CACHE_MASK));
-+ if (! (err = mini_fo_prepare_write(file, page, 0, PAGE_CACHE_SIZE)))
-+ err = mini_fo_commit_write(file, page, 0, PAGE_CACHE_SIZE);
-+
-+ if (err < 0)
-+ goto out;
-+ if (current->need_resched)
-+ schedule();
-+ }
-+
-+ out:
-+ print_exit_status(err);
-+ return err;
-+}
-+
-+
-+
-+STATIC int
-+mini_fo_writepage(page_t *page)
-+{
-+ int err = -EIO;
-+ inode_t *inode;
-+ inode_t *hidden_inode;
-+ page_t *hidden_page;
-+ char *kaddr, *hidden_kaddr;
-+
-+ print_entry_location();
-+
-+ inode = page->mapping->host;
-+ hidden_inode = itohi(inode);
-+
-+ /*
-+ * writepage is called when shared mmap'ed files need to write
-+ * their pages, while prepare/commit_write are called from the
-+ * non-paged write() interface. (However, in 2.3 the two interfaces
-+ * share the same cache, while in 2.2 they didn't.)
-+ *
-+ * So we pretty much have to duplicate much of what commit_write does.
-+ */
-+
-+ /* find lower page (returns a locked page) */
-+ hidden_page = grab_cache_page(hidden_inode->i_mapping, page->index);
-+ if (!hidden_page)
-+ goto out;
-+
-+ /* get page address, and encode it */
-+ kaddr = (char *) kmap(page);
-+ hidden_kaddr = (char*) kmap(hidden_page);
-+ mini_fo_encode_block(kaddr, hidden_kaddr, PAGE_CACHE_SIZE, inode, inode->i_sb, page->index);
-+ /* if encode_block could fail, then return error */
-+ kunmap(page);
-+ kunmap(hidden_page);
-+
-+ /* call lower writepage (expects locked page) */
-+ err = hidden_inode->i_mapping->a_ops->writepage(hidden_page);
-+
-+ /*
-+ * update mtime and ctime of lower level file system
-+ * mini_fo' mtime and ctime are updated by generic_file_write
-+ */
-+ hidden_inode->i_mtime = hidden_inode->i_ctime = CURRENT_TIME;
-+
-+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,1)
-+ UnlockPage(hidden_page); /* b/c grab_cache_page locked it */
-+# endif /* kernel older than 2.4.1 */
-+ page_cache_release(hidden_page); /* b/c grab_cache_page increased refcnt */
-+
-+ if (err)
-+ ClearPageUptodate(page);
-+ else
-+ SetPageUptodate(page);
-+ out:
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,1)
-+ UnlockPage(page);
-+# endif /* kernel 2.4.1 and newer */
-+ print_exit_status(err);
-+ return err;
-+}
-+
-+
-+/*
-+ * get one page from cache or lower f/s, return error otherwise.
-+ * returns unlocked, up-to-date page (if ok), with increased refcnt.
-+ */
-+page_t *
-+mini_fo_get1page(file_t *file, int index)
-+{
-+ page_t *page;
-+ dentry_t *dentry;
-+ inode_t *inode;
-+ struct address_space *mapping;
-+ int err;
-+
-+ print_entry_location();
-+
-+ dentry = file->f_dentry; /* CPW: Moved below print_entry_location */
-+ inode = dentry->d_inode;
-+ mapping = inode->i_mapping;
-+
-+ fist_dprint(8, "%s: read page index %d pid %d\n", __FUNCTION__, index, current->pid);
-+ if (index < 0) {
-+ printk("%s BUG: index=%d\n", __FUNCTION__, index);
-+ page = ERR_PTR(-EIO);
-+ goto out;
-+ }
-+ page = read_cache_page(mapping,
-+ index,
-+ (filler_t *) mapping->a_ops->readpage,
-+ (void *) file);
-+ if (IS_ERR(page))
-+ goto out;
-+ wait_on_page(page);
-+ if (!Page_Uptodate(page)) {
-+ lock_page(page);
-+ err = mapping->a_ops->readpage(file, page);
-+ if (err) {
-+ page = ERR_PTR(err);
-+ goto out;
-+ }
-+ wait_on_page(page);
-+ if (!Page_Uptodate(page)) {
-+ page = ERR_PTR(-EIO);
-+ goto out;
-+ }
-+ }
-+
-+ out:
-+ print_exit_pointer(page);
-+ return page;
-+}
-+
-+
-+/*
-+ * get one page from cache or lower f/s, return error otherwise.
-+ * similar to get1page, but doesn't guarantee that it will return
-+ * an unlocked page.
-+ */
-+page_t *
-+mini_fo_get1page_cached(file_t *file, int index)
-+{
-+ page_t *page;
-+ dentry_t *dentry;
-+ inode_t *inode;
-+ struct address_space *mapping;
-+ int err;
-+
-+ print_entry_location();
-+
-+ dentry = file->f_dentry; /* CPW: Moved below print_entry_location */
-+ inode = dentry->d_inode;
-+ mapping = inode->i_mapping;
-+
-+ fist_dprint(8, "%s: read page index %d pid %d\n", __FUNCTION__, index, current->pid);
-+ if (index < 0) {
-+ printk("%s BUG: index=%d\n", __FUNCTION__, index);
-+ page = ERR_PTR(-EIO);
-+ goto out;
-+ }
-+ page = read_cache_page(mapping,
-+ index,
-+ (filler_t *) mapping->a_ops->readpage,
-+ (void *) file);
-+ if (IS_ERR(page))
-+ goto out;
-+
-+ out:
-+ print_exit_pointer(page);
-+ return page;
-+}
-+
-+
-+/*
-+ * readpage is called from generic_page_read and the fault handler.
-+ * If your file system uses generic_page_read for the read op, it
-+ * must implement readpage.
-+ *
-+ * Readpage expects a locked page, and must unlock it.
-+ */
-+STATIC int
-+mini_fo_do_readpage(file_t *file, page_t *page)
-+{
-+ int err = -EIO;
-+ dentry_t *dentry;
-+ file_t *hidden_file = NULL;
-+ dentry_t *hidden_dentry;
-+ inode_t *inode;
-+ inode_t *hidden_inode;
-+ char *page_data;
-+ page_t *hidden_page;
-+ char *hidden_page_data;
-+ int real_size;
-+
-+ print_entry_location();
-+
-+ dentry = file->f_dentry; /* CPW: Moved below print_entry_location */
-+ if (ftopd(file) != NULL)
-+ hidden_file = ftohf(file);
-+ hidden_dentry = dtohd(dentry);
-+ inode = dentry->d_inode;
-+ hidden_inode = itohi(inode);
-+
-+ fist_dprint(7, "%s: requesting page %d from file %s\n", __FUNCTION__, page->index, dentry->d_name.name);
-+
-+ MALLOC_PAGE_POINTERS(hidden_pages, num_hidden_pages);
-+ MALLOC_PAGEDATA_POINTERS(hidden_pages_data, num_hidden_pages);
-+ FOR_EACH_PAGE
-+ CURRENT_HIDDEN_PAGE = NULL;
-+
-+ /* find lower page (returns a locked page) */
-+ FOR_EACH_PAGE {
-+ fist_dprint(8, "%s: Current page index = %d\n", __FUNCTION__, CURRENT_HIDDEN_PAGEINDEX);
-+ CURRENT_HIDDEN_PAGE = read_cache_page(hidden_inode->i_mapping,
-+ CURRENT_HIDDEN_PAGEINDEX,
-+ (filler_t *) hidden_inode->i_mapping->a_ops->readpage,
-+ (void *) hidden_file);
-+ if (IS_ERR(CURRENT_HIDDEN_PAGE)) {
-+ err = PTR_ERR(CURRENT_HIDDEN_PAGE);
-+ CURRENT_HIDDEN_PAGE = NULL;
-+ goto out_release;
-+ }
-+ }
-+
-+ /*
-+ * wait for the page data to show up
-+ * (signaled by readpage as unlocking the page)
-+ */
-+ FOR_EACH_PAGE {
-+ wait_on_page(CURRENT_HIDDEN_PAGE);
-+ if (!Page_Uptodate(CURRENT_HIDDEN_PAGE)) {
-+ /*
-+ * call readpage() again if we returned from wait_on_page with a
-+ * page that's not up-to-date; that can happen when a partial
-+ * page has a few buffers which are ok, but not the whole
-+ * page.
-+ */
-+ lock_page(CURRENT_HIDDEN_PAGE);
-+ err = hidden_inode->i_mapping->a_ops->readpage(hidden_file,
-+ CURRENT_HIDDEN_PAGE);
-+ if (err) {
-+ CURRENT_HIDDEN_PAGE = NULL;
-+ goto out_release;
-+ }
-+ wait_on_page(CURRENT_HIDDEN_PAGE);
-+ if (!Page_Uptodate(CURRENT_HIDDEN_PAGE)) {
-+ err = -EIO;
-+ goto out_release;
-+ }
-+ }
-+ }
-+
-+ /* map pages, get their addresses */
-+ page_data = (char *) kmap(page);
-+ FOR_EACH_PAGE
-+ CURRENT_HIDDEN_PAGEDATA = (char *) kmap(CURRENT_HIDDEN_PAGE);
-+
-+ /* if decode_block could fail, then return error */
-+ err = 0;
-+ real_size = hidden_inode->i_size - (page->index << PAGE_CACHE_SHIFT);
-+ if (real_size <= 0)
-+ memset(page_data, 0, PAGE_CACHE_SIZE);
-+ else if (real_size < PAGE_CACHE_SIZE) {
-+ mini_fo_decode_block(hidden_page_data, page_data, real_size, inode, inode->i_sb, page->index);
-+ memset(page_data + real_size, 0, PAGE_CACHE_SIZE - real_size);
-+ } else
-+ mini_fo_decode_block(hidden_page_data, page_data, PAGE_CACHE_SIZE, inode, inode->i_sb, page->index);
-+
-+ FOR_EACH_PAGE
-+ kunmap(CURRENT_HIDDEN_PAGE);
-+ kunmap(page);
-+
-+ out_release:
-+ FOR_EACH_PAGE
-+ if (CURRENT_HIDDEN_PAGE)
-+ page_cache_release(CURRENT_HIDDEN_PAGE); /* undo read_cache_page */
-+
-+ FREE_PAGE_POINTERS(hidden_pages, num_hidden_pages);
-+ FREE_PAGEDATA_POINTERS(hidden_pages_data, num_hidden_pages);
-+
-+ out:
-+ if (err == 0)
-+ SetPageUptodate(page);
-+ else
-+ ClearPageUptodate(page);
-+
-+ print_exit_status(err);
-+ return err;
-+}
-+
-+
-+STATIC int
-+mini_fo_readpage(file_t *file, page_t *page)
-+{
-+ int err;
-+ print_entry_location();
-+
-+ err = mini_fo_do_readpage(file, page);
-+
-+ /*
-+ * we have to unlock our page, b/c we _might_ have gotten a locked page.
-+ * but we no longer have to wakeup on our page here, b/c UnlockPage does
-+ * it
-+ */
-+ UnlockPage(page);
-+
-+ print_exit_status(err);
-+ return err;
-+}
-+
-+
-+STATIC int
-+mini_fo_prepare_write(file_t *file, page_t *page, unsigned from, unsigned to)
-+{
-+ int err = 0;
-+
-+ print_entry_location();
-+
-+ /*
-+ * we call kmap(page) only here, and do the kunmap
-+ * and the actual downcalls, including unlockpage and uncache
-+ * in commit_write.
-+ */
-+ kmap(page);
-+
-+ /* fast path for whole page writes */
-+ if (from == 0 && to == PAGE_CACHE_SIZE)
-+ goto out;
-+ /* read the page to "revalidate" our data */
-+ /* call the helper function which doesn't unlock the page */
-+ if (!Page_Uptodate(page))
-+ err = mini_fo_do_readpage(file, page);
-+
-+ out:
-+ print_exit_status(err);
-+ return err;
-+}
-+
-+
-+
-+STATIC int
-+mini_fo_commit_write(file_t *file, page_t *page, unsigned from, unsigned to)
-+{
-+ int err = -ENOMEM;
-+ inode_t *inode;
-+ inode_t *hidden_inode;
-+ page_t *hidden_page;
-+ file_t *hidden_file = NULL;
-+ loff_t pos;
-+ unsigned bytes = to - from;
-+ unsigned hidden_from, hidden_to, hidden_bytes;
-+
-+ print_entry_location();
-+
-+ inode = page->mapping->host; /* CPW: Moved below print_entry_location */
-+ hidden_inode = itohi(inode);
-+
-+ ASSERT(file != NULL);
-+ /*
-+ * here we have a kmapped page, with data from the user copied
-+ * into it. we need to encode_block it, and then call the lower
-+ * commit_write. We also need to simulate same behavior of
-+ * generic_file_write, and call prepare_write on the lower f/s first.
-+ */
-+#ifdef FIST_COUNT_WRITES
-+ count_writes++;
-+# endif /* FIST_COUNT_WRITES */
-+
-+ /* this is append and/or extend -- we can't have holes so fill them in */
-+ if (page->index > (hidden_inode->i_size >> PAGE_CACHE_SHIFT)) {
-+ page_t *tmp_page;
-+ int index;
-+ for (index = hidden_inode->i_size >> PAGE_CACHE_SHIFT; index < page->index; index++) {
-+ tmp_page = mini_fo_get1page(file, index);
-+ if (IS_ERR(tmp_page)) {
-+ err = PTR_ERR(tmp_page);
-+ goto out;
-+ }
-+ /* zero out the contents of the page at the appropriate offsets */
-+ memset((char*)page_address(tmp_page) + (inode->i_size & ~PAGE_CACHE_MASK), 0, PAGE_CACHE_SIZE - (inode->i_size & ~PAGE_CACHE_MASK));
-+ if (!(err = mini_fo_prepare_write(file, tmp_page, 0, PAGE_CACHE_SIZE)))
-+ err = mini_fo_commit_write(file, tmp_page, 0, PAGE_CACHE_SIZE);
-+ page_cache_release(tmp_page);
-+ if (err < 0)
-+ goto out;
-+ if (current->need_resched)
-+ schedule();
-+ }
-+ }
-+
-+ if (ftopd(file) != NULL)
-+ hidden_file = ftohf(file);
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_inode->i_mutex);
-+#else
-+ down(&hidden_inode->i_sem);
-+#endif
-+ /* find lower page (returns a locked page) */
-+ hidden_page = grab_cache_page(hidden_inode->i_mapping, page->index);
-+ if (!hidden_page)
-+ goto out;
-+
-+#if FIST_ENCODING_BLOCKSIZE > 1
-+# error encoding_blocksize greater than 1 is not yet supported
-+# endif /* FIST_ENCODING_BLOCKSIZE > 1 */
-+
-+ hidden_from = from & (~(FIST_ENCODING_BLOCKSIZE - 1));
-+ hidden_to = ((to + FIST_ENCODING_BLOCKSIZE - 1) & (~(FIST_ENCODING_BLOCKSIZE - 1)));
-+ if ((page->index << PAGE_CACHE_SHIFT) + to > hidden_inode->i_size) {
-+
-+ /*
-+ * if this call to commit_write had introduced holes and the code
-+ * for handling holes was invoked, then the beginning of this page
-+ * must be zeroed out
-+ * zero out bytes from 'size_of_file%pagesize' to 'from'.
-+ */
-+ if ((hidden_from - (inode->i_size & ~PAGE_CACHE_MASK)) > 0)
-+ memset((char*)page_address(page) + (inode->i_size & ~PAGE_CACHE_MASK), 0, hidden_from - (inode->i_size & ~PAGE_CACHE_MASK));
-+
-+ }
-+ hidden_bytes = hidden_to - hidden_from;
-+
-+ /* call lower prepare_write */
-+ err = -EINVAL;
-+ if (hidden_inode->i_mapping &&
-+ hidden_inode->i_mapping->a_ops &&
-+ hidden_inode->i_mapping->a_ops->prepare_write)
-+ err = hidden_inode->i_mapping->a_ops->prepare_write(hidden_file,
-+ hidden_page,
-+ hidden_from,
-+ hidden_to);
-+ if (err)
-+ /* don't leave locked pages behind, esp. on an ENOSPC */
-+ goto out_unlock;
-+
-+ fist_dprint(8, "%s: encoding %d bytes\n", __FUNCTION__, hidden_bytes);
-+ mini_fo_encode_block((char *) page_address(page) + hidden_from, (char*) page_address(hidden_page) + hidden_from, hidden_bytes, inode, inode->i_sb, page->index);
-+ /* if encode_block could fail, then goto unlock and return error */
-+
-+ /* call lower commit_write */
-+ err = hidden_inode->i_mapping->a_ops->commit_write(hidden_file,
-+ hidden_page,
-+ hidden_from,
-+ hidden_to);
-+
-+ if (err < 0)
-+ goto out_unlock;
-+
-+ err = bytes; /* convert error to no. of bytes */
-+
-+ inode->i_blocks = hidden_inode->i_blocks;
-+ /* we may have to update i_size */
-+ pos = (page->index << PAGE_CACHE_SHIFT) + to;
-+ if (pos > inode->i_size)
-+ inode->i_size = pos;
-+
-+ /*
-+ * update mtime and ctime of lower level file system
-+ * mini_fo' mtime and ctime are updated by generic_file_write
-+ */
-+ hidden_inode->i_mtime = hidden_inode->i_ctime = CURRENT_TIME;
-+
-+ mark_inode_dirty_sync(inode);
-+
-+ out_unlock:
-+ UnlockPage(hidden_page);
-+ page_cache_release(hidden_page);
-+ kunmap(page); /* kmap was done in prepare_write */
-+ out:
-+ /* we must set our page as up-to-date */
-+ if (err < 0)
-+ ClearPageUptodate(page);
-+ else
-+ SetPageUptodate(page);
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_inode->i_mutex);
-+#else
-+ up(&hidden_inode->i_sem);
-+#endif
-+ print_exit_status(err);
-+ return err; /* assume all is ok */
-+}
-+
-+
-+STATIC int
-+mini_fo_bmap(struct address_space *mapping, long block)
-+{
-+ int err = 0;
-+ inode_t *inode;
-+ inode_t *hidden_inode;
-+
-+ print_entry_location();
-+
-+ inode = (inode_t *) mapping->host;
-+ hidden_inode = itohi(inode);
-+
-+ if (hidden_inode->i_mapping->a_ops->bmap)
-+ err = hidden_inode->i_mapping->a_ops->bmap(hidden_inode->i_mapping, block);
-+ print_exit_location();
-+ return err;
-+}
-+
-+
-+/*
-+ * This function is copied verbatim from mm/filemap.c.
-+ * XXX: It should be simply moved to some header file instead -- bug Al about it!
-+ */
-+static inline int sync_page(struct page *page)
-+{
-+ struct address_space *mapping = page->mapping;
-+
-+ if (mapping && mapping->a_ops && mapping->a_ops->sync_page)
-+ return mapping->a_ops->sync_page(page);
-+ return 0;
-+}
-+
-+
-+/*
-+ * XXX: we may not need this function if not FIST_FILTER_DATA.
-+ * FIXME: for FIST_FILTER_SCA, get all lower pages and sync them each.
-+ */
-+STATIC int
-+mini_fo_sync_page(page_t *page)
-+{
-+ int err = 0;
-+ inode_t *inode;
-+ inode_t *hidden_inode;
-+ page_t *hidden_page;
-+
-+ print_entry_location();
-+
-+ inode = page->mapping->host; /* CPW: Moved below print_entry_location */
-+ hidden_inode = itohi(inode);
-+
-+ /* find lower page (returns a locked page) */
-+ hidden_page = grab_cache_page(hidden_inode->i_mapping, page->index);
-+ if (!hidden_page)
-+ goto out;
-+
-+ err = sync_page(hidden_page);
-+
-+ UnlockPage(hidden_page); /* b/c grab_cache_page locked it */
-+ page_cache_release(hidden_page); /* b/c grab_cache_page increased refcnt */
-+
-+ out:
-+ print_exit_status(err);
-+ return err;
-+}
---- /dev/null
-+++ b/fs/mini_fo/README
-@@ -0,0 +1,163 @@
-+README for the mini_fo overlay file system
-+=========================================
-+
-+
-+WHAT IS MINI_FO?
-+----------------
-+
-+mini_fo is a virtual kernel file system that can make read-only
-+file systems writable. This is done by redirecting modifying operations
-+to a writeable location called "storage directory", and leaving the
-+original data in the "base directory" untouched. When reading, the
-+file system merges the modifed and original data so that only the
-+newest versions will appear. This occurs transparently to the user,
-+who can access the data like on any other read-write file system.
-+
-+Base and storage directories may be located on the same or on
-+different partitions and may be of different file system types. While
-+the storage directory obviously needs to be writable, the base may or
-+may not be writable, what doesn't matter as it will no be modified
-+anyway.
-+
-+
-+WHAT IS GOOD FOR?
-+-----------------
-+
-+The primary purpose of the mini_fo file system is to allow easy
-+software updates to embedded systems, that often store their root
-+file system in a read-only flash file system, but there are many
-+more as for example sandboxing, or for allowing live-cds to
-+permanently store information.
-+
-+
-+BUILDING
-+--------
-+This should be simple. Adjust the Makefile to point to the correct
-+kernel headers you want to build the module for. Then:
-+
-+ # make
-+
-+should build "mini_fo.o" for a 2.4 kernel or "mini_fo.ko" for a 2.6
-+kernel.
-+
-+If you are building the module for you current kernel, you can install
-+the module (as root):
-+
-+ # make install
-+
-+or uninstall with
-+
-+ # make uninstall
-+
-+
-+USING THE FILE SYSTEM
-+--------------------
-+
-+the general mount syntax is:
-+
-+ mount -t mini_fo -o base=<base directory>,sto=<storage directory>\
-+ <base directory> <mount point>
-+
-+Example:
-+
-+You have mounted a cdrom to /mnt/cdrom and want to modifiy some files
-+on it:
-+
-+load the module (as root)
-+
-+ # insmod mini_fo.o for a 2.4 kernel or
-+
-+ # insmod mini_fo.ko for a 2.6 kernel
-+
-+
-+create a storage dir in tmp and a mountpoint for mini_fo:
-+
-+ # mkdir /tmp/sto
-+ # mkdir /mnt/mini_fo
-+
-+and mount the mini_fo file system:
-+
-+ # mount -t mini_fo -o base=/mnt/cdrom,sto=/tmp/sto /mnt/cdrom /mnt/mini_fo
-+
-+
-+Now the data stored on the cd can be accessed via the mini_fo
-+mountpoint just like any read-write file system, files can be modified
-+and deleted, new ones can be created and so on. When done unmount the
-+file system:
-+
-+ # unmount /mnt/mini_fo
-+
-+Note that if the file system is mounted again using the same storage
-+file system, of course it will appear in the modified state again. If
-+you remount it using an new empty storage directory, it will be
-+unmodified. Therefore by executing:
-+
-+ # cd /tmp/sto
-+ # rm -rf *
-+
-+you can nuke all the changes you made to the original file system. But
-+ remember NEVER do this while the mini_fo file system is mounted!
-+
-+
-+Alternatively you can use the mini_fo-overlay bash script, that
-+simplifies managing mini_fo mounts. See TOOLS Section.
-+
-+
-+TOOLS
-+-----
-+
-+mini_fo-merge (experimental):
-+
-+This is a bash script that will merge changes contained in the storage
-+directory back to the base directory. This allows mini_fo to function
-+as a cache file system by overlaying a slow (network, ...) file system
-+and using a fast (ramdisk, ...) as storage. When done, changes can be
-+merged back to the (slow) base with mini_fo-merge. See "mini_fo-merge
-+-h" for details.
-+
-+It can be usefull for merging changes back after a successfull test
-+(patches, software updates...)
-+
-+
-+mini_fo-overlay:
-+
-+This bash script simplifies managing one or more mini_fo mounts. For
-+overlaying a directory called "basedir1", you can just call:
-+
-+ # mini_fo-overlay basedir1
-+
-+This will mount mini_fo with "basedir1" as base, "/tmp/sto-basedir1/"
-+as storage to "/mnt/mini_fo-basedir1/". It has more options though,
-+type "mini_fo-overlay -h" for details.
-+
-+
-+DOCUMENTATION, REPORTING BUGS, GETTING HELP
-+-------------------------------------------
-+
-+Please visit the mini_fo project page at:
-+
-+http://www.denx.de/twiki/bin/view/Know/MiniFOHome
-+
-+
-+WARNINGS
-+--------
-+
-+Never modify the base or the storage directorys while the mini_fo
-+file system is mounted, or you might crash you system. Simply accessing
-+and reading should not cause any trouble.
-+
-+Exporting a mini_fo mount point via NFS has not been tested, and may
-+or may not work.
-+
-+Check the RELEASE_NOTES for details on bugs and features.
-+
-+
-+
-+Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
-+
-+This program is free software; you can redistribute it and/or
-+modify it under the terms of the GNU General Public License
-+as published by the Free Software Foundation; either version
-+2 of the License, or (at your option) any later version.
-+
-+
---- /dev/null
-+++ b/fs/mini_fo/RELEASE_NOTES
-@@ -0,0 +1,111 @@
-+Release: mini_fo-0.6.1 (v0-6-1)
-+Date: 21.09.2005
-+
-+
-+Changes:
-+--------
-+v0-6-1:
-+
-+- bugfixes (see ChangeLog)
-+
-+- two helper scripts "mini_fo_merge" and "mini_fo_overlay" (see
-+ README for details).
-+
-+v0-6-0:
-+
-+- Support for 2.4 and 2.6 (see Makefile)
-+
-+- Partial hard link support (creating works as expected, but already
-+ existing links in the base file system will be treated as if they
-+ were individual files).
-+
-+- Various bugfixes and cleanups.
-+
-+
-+v0-6-0-pre1:
-+
-+- This is mini_fo-0-6-0-pre1! This release is a complete rewrite of
-+ many vital mini_fo parts such as the old whiteout list code which
-+ has been replaced by the new META subsystem.
-+
-+- Light weight directory renaming implemented. This means if a
-+ directory is renamed via the mini_fo filesystem this will no longer
-+ result in a complete copy in storage, instead only one empty
-+ directory will be created. All base filed contained in the original
-+ directory stay there until modified.
-+
-+- Special files (creating, renaming, deleting etc.) now working.
-+
-+- Many bugfixes and cleanup, mini_fo is now a lot more stable.
-+
-+
-+v0-5-10:
-+
-+- Final release of the 0-5-* versions. Next will be a complete rewrite
-+ of many features. This release contains several bugfixes related to
-+ directory renaming.
-+
-+
-+v0-5-10-pre6:
-+
-+- Lots of cleanup and several bugfixes related to directory deleting
-+
-+- Directory renaming suddenly works, what is most likely due to the
-+ fact tha that "mv" is smart: if the classic rename doesn't work it
-+ will assume that source and target file are on different fs and will
-+ copy the directory and try to remove the source directory. Until
-+ directory removing wasn't implemented, it would fail to do this and
-+ rollback.
-+ So, directory renaming works for now, but it doesn't yet do what you
-+ would expect from a overlay fs, so use with care.
-+
-+
-+v0-5-10-pre5:
-+
-+- implemented directory deleting
-+- made parsing of mount options more stable
-+- New format of mount options! (See README)
-+- I can't reproduce the unknown panic with 2.4.25 anymore, so I'll
-+ happily assume it never existed!
-+
-+
-+Implemented features:
-+---------------------
-+
-+- creating hard links (see BUGS on already existing hard links)
-+- lightweight directory renaming
-+- renaming device files, pipes, sockets, etc.
-+- creating, renaming, deleting of special files
-+- deleting directorys
-+- general directory reading (simple "ls" )
-+- creating files in existing directorys
-+- creating directorys
-+- renaming files.
-+- reading and writing files (involves opening)
-+- appending to files (creates copy in storage)
-+- deleting files
-+- llseek works too, what allows editors to work
-+- persistency (a deleted file stay deleted over remounts)
-+- use of symbolic links
-+- creating of device files
-+
-+
-+Not (yet) implemented features:
-+-------------------------------
-+
-+- full hard link support.
-+
-+
-+
-+BUGS:
-+-----
-+
-+Hard links in the base file system will be treated as individual
-+files, not as links to one inode.
-+
-+The main problem with hard links isn't allowing to create them, but
-+their pure existence. If you modify a base hard link, the changes made
-+will only show up on this link, the other link will remain in the
-+original state. I hope to fix this someday. Please note that this does
-+not effect the special hard links '.' and '..', that are handled
-+seperately by the lower fs.
---- /dev/null
-+++ b/fs/mini_fo/state.c
-@@ -0,0 +1,620 @@
-+/*
-+ * Copyright (C) 2005 Markus Klotzbuecher <mk@creamnet.de>
-+ *
-+ * This program is free software; you can redistribute it and/or
-+ * modify it under the terms of the GNU General Public License
-+ * as published by the Free Software Foundation; either version
-+ * 2 of the License, or (at your option) any later version.
-+ */
-+
-+#ifdef HAVE_CONFIG_H
-+# include <config.h>
-+#endif /* HAVE_CONFIG_H */
-+
-+#include "fist.h"
-+#include "mini_fo.h"
-+
-+
-+/* create the storage file, setup new states */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+int create_sto_reg_file(dentry_t *dentry, int mode, struct nameidata *nd)
-+#else
-+int create_sto_reg_file(dentry_t *dentry, int mode)
-+#endif
-+{
-+ int err = 0;
-+ inode_t *dir;
-+ dentry_t *hidden_sto_dentry;
-+ dentry_t *hidden_sto_dir_dentry;
-+
-+ if(exists_in_storage(dentry)) {
-+ printk(KERN_CRIT "mini_fo: create_sto_file: wrong type or state.\n");
-+ err = -EINVAL;
-+ goto out;
-+ }
-+ err = get_neg_sto_dentry(dentry);
-+
-+ if (err) {
-+ printk(KERN_CRIT "mini_fo: create_sto_file: ERROR getting neg. sto dentry.\n");
-+ goto out;
-+ }
-+
-+ dir = dentry->d_parent->d_inode;
-+ hidden_sto_dentry = dtohd2(dentry);
-+
-+ /* lock parent */
-+ hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+
-+ err = PTR_ERR(hidden_sto_dir_dentry);
-+ if (IS_ERR(hidden_sto_dir_dentry))
-+ goto out;
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ err = vfs_create(hidden_sto_dir_dentry->d_inode,
-+ hidden_sto_dentry,
-+ mode, nd);
-+#else
-+ err = vfs_create(hidden_sto_dir_dentry->d_inode,
-+ hidden_sto_dentry,
-+ mode);
-+#endif
-+ if(err) {
-+ printk(KERN_CRIT "mini_fo: create_sto_file: ERROR creating sto file.\n");
-+ goto out_lock;
-+ }
-+
-+ if(!dtohd2(dentry)->d_inode) {
-+ printk(KERN_CRIT "mini_fo: create_sto_file: ERROR creating sto file [2].\n");
-+ err = -EINVAL;
-+ goto out_lock;
-+ }
-+
-+ /* interpose the new inode */
-+ if(dtost(dentry) == DELETED) {
-+ dtost(dentry) = DEL_REWRITTEN;
-+ err = mini_fo_tri_interpose(NULL, hidden_sto_dentry, dentry, dir->i_sb, 0);
-+ if(err)
-+ goto out_lock;
-+ }
-+ else if(dtost(dentry) == NON_EXISTANT) {
-+ dtost(dentry) = CREATED;
-+ err = mini_fo_tri_interpose(dtohd(dentry), hidden_sto_dentry, dentry, dir->i_sb, 0);
-+ if(err)
-+ goto out_lock;
-+ }
-+ else if(dtost(dentry) == UNMODIFIED) {
-+ dtost(dentry) = MODIFIED;
-+ /* interpose on new inode */
-+ if(itohi2(dentry->d_inode) != NULL) {
-+ printk(KERN_CRIT "mini_fo: create_sto_file: invalid inode detected.\n");
-+ err = -EINVAL;
-+ goto out_lock;
-+ }
-+ itohi2(dentry->d_inode) = igrab(dtohd2(dentry)->d_inode);
-+ }
-+ fist_copy_attr_timesizes(dentry->d_parent->d_inode,
-+ hidden_sto_dir_dentry->d_inode);
-+
-+ out_lock:
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+ dput(hidden_sto_dir_dentry);
-+ out:
-+ return err;
-+}
-+
-+/* create the sto dir, setup states */
-+int create_sto_dir(dentry_t *dentry, int mode)
-+{
-+ int err = 0;
-+ inode_t *dir;
-+ dentry_t *hidden_sto_dentry;
-+ dentry_t *hidden_sto_dir_dentry;
-+
-+ /* had to take the "!S_ISDIR(mode))" check out, because it failed */
-+ if(exists_in_storage(dentry)) {
-+ printk(KERN_CRIT "mini_fo: create_sto_dir: wrong type or state.\\
-+n");
-+ err = -EINVAL;
-+ goto out;
-+ }
-+
-+ err = get_neg_sto_dentry(dentry);
-+ if(err) {
-+ err = -EINVAL;
-+ goto out;
-+ }
-+
-+ dir = dentry->d_parent->d_inode;
-+ hidden_sto_dentry = dtohd2(dentry);
-+
-+ /* was: hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry); */
-+ hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+
-+ err = PTR_ERR(hidden_sto_dir_dentry);
-+ if (IS_ERR(hidden_sto_dir_dentry))
-+ goto out;
-+
-+ err = vfs_mkdir(hidden_sto_dir_dentry->d_inode,
-+ hidden_sto_dentry,
-+ mode);
-+ if(err) {
-+ printk(KERN_CRIT "mini_fo: create_sto_dir: ERROR creating sto dir.\n");
-+ goto out_lock;
-+ }
-+
-+ if(!dtohd2(dentry)->d_inode) {
-+ printk(KERN_CRIT "mini_fo: create_sto_dir: ERROR creating sto dir [2].\n");
-+ err = -EINVAL;
-+ goto out_lock;
-+ }
-+
-+ /* interpose the new inode */
-+ if(dtost(dentry) == DELETED) {
-+ dtost(dentry) = DEL_REWRITTEN;
-+ err = mini_fo_tri_interpose(NULL, hidden_sto_dentry, dentry, dir->i_sb, 0);
-+ if(err)
-+ goto out_lock;
-+ }
-+ else if(dtopd(dentry)->state == NON_EXISTANT) {
-+ dtopd(dentry)->state = CREATED;
-+ err = mini_fo_tri_interpose(dtohd(dentry), hidden_sto_dentry, dentry, dir->i_sb, 0);
-+ if(err)
-+ goto out_lock;
-+ }
-+ else if(dtopd(dentry)->state == UNMODIFIED) {
-+ dtopd(dentry)->state = MODIFIED;
-+ /* interpose on new inode */
-+ if(itohi2(dentry->d_inode) != NULL) {
-+ printk(KERN_CRIT "mini_fo: create_sto_dir: ERROR, invalid inode detected.\n");
-+ err = -EINVAL;
-+ goto out_lock;
-+ }
-+ itohi2(dentry->d_inode) = igrab(dtohd2(dentry)->d_inode);
-+ }
-+
-+ fist_copy_attr_timesizes(dir, hidden_sto_dir_dentry->d_inode);
-+
-+ /* initalize the wol list */
-+ itopd(dentry->d_inode)->deleted_list_size = -1;
-+ itopd(dentry->d_inode)->renamed_list_size = -1;
-+ meta_build_lists(dentry);
-+
-+
-+ out_lock:
-+ /* was: unlock_dir(hidden_sto_dir_dentry); */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+ dput(hidden_sto_dir_dentry);
-+ out:
-+ return err;
-+}
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+int create_sto_nod(dentry_t *dentry, int mode, dev_t dev)
-+#else
-+int create_sto_nod(dentry_t *dentry, int mode, int dev)
-+#endif
-+{
-+ int err = 0;
-+ inode_t *dir;
-+ dentry_t *hidden_sto_dentry;
-+ dentry_t *hidden_sto_dir_dentry;
-+
-+ if(exists_in_storage(dentry)) {
-+ err = -EEXIST;
-+ goto out;
-+ }
-+ err = get_neg_sto_dentry(dentry);
-+
-+ if (err) {
-+ printk(KERN_CRIT "mini_fo: create_sto_nod: ERROR getting neg. sto dentry.\n");
-+ goto out;
-+ }
-+
-+ dir = dentry->d_parent->d_inode;
-+ hidden_sto_dentry = dtohd2(dentry);
-+
-+ /* lock parent */
-+ hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+
-+ err = PTR_ERR(hidden_sto_dir_dentry);
-+ if (IS_ERR(hidden_sto_dir_dentry))
-+ goto out;
-+
-+ err = vfs_mknod(hidden_sto_dir_dentry->d_inode, hidden_sto_dentry, mode, dev);
-+ if(err)
-+ goto out_lock;
-+
-+ if(!dtohd2(dentry)->d_inode) {
-+ printk(KERN_CRIT "mini_fo: create_sto_nod: creating storage inode failed [1].\n");
-+ err = -EINVAL; /* return something indicating failure */
-+ goto out_lock;
-+ }
-+
-+ /* interpose the new inode */
-+ if(dtost(dentry) == DELETED) {
-+ dtost(dentry) = DEL_REWRITTEN;
-+ err = mini_fo_tri_interpose(NULL, hidden_sto_dentry, dentry, dir->i_sb, 0);
-+ if(err)
-+ goto out_lock;
-+ }
-+ else if(dtost(dentry) == NON_EXISTANT) {
-+ dtost(dentry) = CREATED;
-+ err = mini_fo_tri_interpose(dtohd(dentry), hidden_sto_dentry, dentry, dir->i_sb, 0);
-+ if(err)
-+ goto out_lock;
-+ }
-+ else if(dtost(dentry) == UNMODIFIED) {
-+ dtost(dentry) = MODIFIED;
-+ /* interpose on new inode */
-+ if(itohi2(dentry->d_inode) != NULL) {
-+ printk(KERN_CRIT "mini_fo: create_sto_nod: error, invalid inode detected.\n");
-+ err = -EINVAL;
-+ goto out_lock;
-+ }
-+ itohi2(dentry->d_inode) = igrab(dtohd2(dentry)->d_inode);
-+ }
-+
-+ fist_copy_attr_timesizes(dir, hidden_sto_dir_dentry->d_inode);
-+
-+ out_lock:
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+ dput(hidden_sto_dir_dentry);
-+ out:
-+ return err;
-+}
-+
-+
-+/* unimplemented (and possibly not usefull):
-+
-+ nondir-del_to_del_rew
-+ nondir-non_exist_to_creat
-+
-+ dir-unmod_to_del
-+ dir-mod_to_del
-+ dir-creat_to_del
-+ dir-del_rew_to_del
-+ dir-del_to_del_rew
-+ dir-non_exist_to_creat
-+*/
-+
-+
-+/* bring a file of any type from state UNMODIFIED to MODIFIED */
-+int nondir_unmod_to_mod(dentry_t *dentry, int cp_flag)
-+{
-+ int err = 0;
-+ struct vfsmount *tgt_mnt;
-+ struct vfsmount *src_mnt;
-+ dentry_t *tgt_dentry;
-+ dentry_t *src_dentry;
-+ dentry_t *hidden_sto_dentry;
-+ dentry_t *hidden_sto_dir_dentry;
-+
-+ check_mini_fo_dentry(dentry);
-+
-+ if((dtost(dentry) != UNMODIFIED) ||
-+ S_ISDIR(dentry->d_inode->i_mode)) {
-+ printk(KERN_CRIT "mini_fo: nondir_unmod_to_mod: \
-+ wrong type or state.\n");
-+ err = -1;
-+ goto out;
-+ }
-+ err = get_neg_sto_dentry(dentry);
-+
-+ if (err) {
-+ printk(KERN_CRIT "mini_fo: nondir_unmod_to_mod: \
-+ ERROR getting neg. sto dentry.\n");
-+ goto out;
-+ }
-+
-+ /* create sto file */
-+ hidden_sto_dentry = dtohd2(dentry);
-+
-+ /* lock parent */
-+ hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+
-+ err = PTR_ERR(hidden_sto_dir_dentry);
-+ if (IS_ERR(hidden_sto_dir_dentry))
-+ goto out;
-+
-+ /* handle different types of nondirs */
-+ if(S_ISCHR(dentry->d_inode->i_mode) ||
-+ S_ISBLK(dentry->d_inode->i_mode)) {
-+ err = vfs_mknod(hidden_sto_dir_dentry->d_inode,
-+ hidden_sto_dentry,
-+ dtohd(dentry)->d_inode->i_mode,
-+ dtohd(dentry)->d_inode->i_rdev);
-+ }
-+
-+ else if(S_ISREG(dentry->d_inode->i_mode)) {
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ err = vfs_create(hidden_sto_dir_dentry->d_inode,
-+ hidden_sto_dentry,
-+ dtohd(dentry)->d_inode->i_mode, NULL);
-+#else
-+ err = vfs_create(hidden_sto_dir_dentry->d_inode,
-+ hidden_sto_dentry,
-+ dtohd(dentry)->d_inode->i_mode);
-+#endif
-+ }
-+ if(err) {
-+ printk(KERN_CRIT "mini_fo: nondir_unmod_to_mod: \
-+ ERROR creating sto file.\n");
-+ goto out_lock;
-+ }
-+
-+ /* interpose on new inode */
-+ if(itohi2(dentry->d_inode) != NULL) {
-+ printk(KERN_CRIT "mini_fo: nondir_unmod_to_mod: \
-+ ERROR, invalid inode detected.\n");
-+ err = -EINVAL;
-+ goto out_lock;
-+ }
-+
-+ itohi2(dentry->d_inode) = igrab(dtohd2(dentry)->d_inode);
-+
-+ fist_copy_attr_timesizes(dentry->d_parent->d_inode,
-+ hidden_sto_dir_dentry->d_inode);
-+ dtost(dentry) = MODIFIED;
-+
-+ /* copy contents if regular file and cp_flag = 1 */
-+ if((cp_flag == 1) && S_ISREG(dentry->d_inode->i_mode)) {
-+
-+ /* unlock first */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+
-+ dput(hidden_sto_dir_dentry);
-+
-+ tgt_dentry = dtohd2(dentry);
-+ tgt_mnt = stopd(dentry->d_inode->i_sb)->hidden_mnt2;
-+ src_dentry = dtohd(dentry);
-+ src_mnt = stopd(dentry->d_inode->i_sb)->hidden_mnt;
-+
-+ err = mini_fo_cp_cont(tgt_dentry, tgt_mnt,
-+ src_dentry, src_mnt);
-+ if(err) {
-+ printk(KERN_CRIT "mini_fo: nondir_unmod_to_mod: \
-+ ERROR copying contents.\n");
-+ }
-+ goto out;
-+ }
-+
-+ out_lock:
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+ dput(hidden_sto_dir_dentry);
-+ out:
-+ return err;
-+}
-+
-+/* this function is currently identical to nondir_creat_to_del */
-+int nondir_del_rew_to_del(dentry_t *dentry)
-+{
-+ return nondir_creat_to_del(dentry);
-+}
-+
-+int nondir_creat_to_del(dentry_t *dentry)
-+{
-+ int err = 0;
-+
-+ inode_t *hidden_sto_dir_inode;
-+ dentry_t *hidden_sto_dir_dentry;
-+ dentry_t *hidden_sto_dentry;
-+
-+ check_mini_fo_dentry(dentry);
-+
-+ /* for now this function serves for both state DEL_REWRITTEN and
-+ * CREATED */
-+ if(!(dtost(dentry) == CREATED || (dtost(dentry) == DEL_REWRITTEN)) ||
-+ S_ISDIR(dentry->d_inode->i_mode)) {
-+ printk(KERN_CRIT "mini_fo: nondir_mod_to_del/del_rew_to_del: \
-+ wrong type or state.\n");
-+ err = -1;
-+ goto out;
-+ }
-+
-+ hidden_sto_dir_inode = itohi2(dentry->d_parent->d_inode);
-+ hidden_sto_dentry = dtohd2(dentry);
-+
-+ /* was: hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry);*/
-+ hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+
-+ /* avoid destroying the hidden inode if the file is in use */
-+ dget(hidden_sto_dentry);
-+ err = vfs_unlink(hidden_sto_dir_inode, hidden_sto_dentry);
-+ dput(hidden_sto_dentry);
-+ if(!err)
-+ d_delete(hidden_sto_dentry);
-+
-+ /* propagate number of hard-links */
-+ dentry->d_inode->i_nlink = itohi2(dentry->d_inode)->i_nlink;
-+
-+ dtost(dentry) = NON_EXISTANT;
-+
-+ /* was: unlock_dir(hidden_sto_dir_dentry); */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+ dput(hidden_sto_dir_dentry);
-+
-+ out:
-+ return err;
-+}
-+
-+int nondir_mod_to_del(dentry_t *dentry)
-+{
-+ int err;
-+ dentry_t *hidden_sto_dentry;
-+ inode_t *hidden_sto_dir_inode;
-+ dentry_t *hidden_sto_dir_dentry;
-+
-+ check_mini_fo_dentry(dentry);
-+
-+ if(dtost(dentry) != MODIFIED ||
-+ S_ISDIR(dentry->d_inode->i_mode)) {
-+ printk(KERN_CRIT "mini_fo: nondir_mod_to_del: \
-+ wrong type or state.\n");
-+ err = -1;
-+ goto out;
-+ }
-+
-+ hidden_sto_dir_inode = itohi2(dentry->d_parent->d_inode);
-+ hidden_sto_dentry = dtohd2(dentry);
-+
-+ /* was hidden_sto_dir_dentry = lock_parent(hidden_sto_dentry); */
-+ hidden_sto_dir_dentry = dget(hidden_sto_dentry->d_parent);
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_lock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ down(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+
-+ /* avoid destroying the hidden inode if the file is in use */
-+ dget(hidden_sto_dentry);
-+ err = vfs_unlink(hidden_sto_dir_inode, hidden_sto_dentry);
-+ dput(hidden_sto_dentry);
-+ if(!err)
-+ d_delete(hidden_sto_dentry);
-+
-+ /* propagate number of hard-links */
-+ dentry->d_inode->i_nlink = itohi2(dentry->d_inode)->i_nlink;
-+
-+ /* dput base dentry, this will relase the inode and free the
-+ * dentry, as we will never need it again. */
-+ dput(dtohd(dentry));
-+ dtohd(dentry) = NULL;
-+ dtost(dentry) = DELETED;
-+
-+ /* add deleted file to META-file */
-+ meta_add_d_entry(dentry->d_parent,
-+ dentry->d_name.name,
-+ dentry->d_name.len);
-+
-+ /* was: unlock_dir(hidden_sto_dir_dentry); */
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
-+ mutex_unlock(&hidden_sto_dir_dentry->d_inode->i_mutex);
-+#else
-+ up(&hidden_sto_dir_dentry->d_inode->i_sem);
-+#endif
-+ dput(hidden_sto_dir_dentry);
-+
-+ out:
-+ return err;
-+}
-+
-+int nondir_unmod_to_del(dentry_t *dentry)
-+{
-+ int err = 0;
-+
-+ check_mini_fo_dentry(dentry);
-+
-+ if(dtost(dentry) != UNMODIFIED ||
-+ S_ISDIR(dentry->d_inode->i_mode)) {
-+ printk(KERN_CRIT "mini_fo: nondir_unmod_to_del: \
-+ wrong type or state.\n");
-+ err = -1;
-+ goto out;
-+ }
-+
-+ /* next we have to get a negative dentry for the storage file */
-+ err = get_neg_sto_dentry(dentry);
-+
-+ if(err)
-+ goto out;
-+
-+ /* add deleted file to META lists */
-+ err = meta_add_d_entry(dentry->d_parent,
-+ dentry->d_name.name,
-+ dentry->d_name.len);
-+
-+ if(err)
-+ goto out;
-+
-+ /* dput base dentry, this will relase the inode and free the
-+ * dentry, as we will never need it again. */
-+ dput(dtohd(dentry));
-+ dtohd(dentry) = NULL;
-+ dtost(dentry) = DELETED;
-+
-+ out:
-+ return err;
-+}
-+
-+/* bring a dir from state UNMODIFIED to MODIFIED */
-+int dir_unmod_to_mod(dentry_t *dentry)
-+{
-+ int err;
-+
-+ check_mini_fo_dentry(dentry);
-+
-+ if(dtost(dentry) != UNMODIFIED ||
-+ !S_ISDIR(dentry->d_inode->i_mode)) {
-+ printk(KERN_CRIT "mini_fo: dir_unmod_to_mod: \
-+ wrong type or state.\n");
-+ err = -1;
-+ goto out;
-+ }
-+
-+ /* this creates our dir incl. sto. structure */
-+ err = build_sto_structure(dentry->d_parent, dentry);
-+ if(err) {
-+ printk(KERN_CRIT "mini_fo: dir_unmod_to_mod: \
-+ build_sto_structure failed.\n");
-+ goto out;
-+ }
-+ out:
-+ return err;
-+}
-+
---- /dev/null
-+++ b/fs/mini_fo/super.c
-@@ -0,0 +1,285 @@
-+/*
-+ * Copyright (c) 1997-2003 Erez Zadok
-+ * Copyright (c) 2001-2003 Stony Brook University
-+ *
-+ * For specific licensing information, see the COPYING file distributed with
-+ * this package, or get one from ftp://ftp.filesystems.org/pub/fist/COPYING.
-+ *
-+ * This Copyright notice must be kept intact and distributed with all
-+ * fistgen sources INCLUDING sources generated by fistgen.
-+ */
-+/*
-+ * Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>
-+ *
-+ * This program is free software; you can redistribute it and/or
-+ * modify it under the terms of the GNU General Public License
-+ * as published by the Free Software Foundation; either version
-+ * 2 of the License, or (at your option) any later version.
-+ */
-+
-+/*
-+ * $Id$
-+ */
-+
-+#ifdef HAVE_CONFIG_H
-+# include <config.h>
-+#endif
-+
-+#include "fist.h"
-+#include "mini_fo.h"
-+
-+
-+STATIC void
-+mini_fo_read_inode(inode_t *inode)
-+{
-+ static struct address_space_operations mini_fo_empty_aops;
-+
-+ __itopd(inode) = kmalloc(sizeof(struct mini_fo_inode_info), GFP_KERNEL);
-+ if (!itopd(inode)) {
-+ printk("<0>%s:%s:%d: No kernel memory!\n", __FILE__, __FUNCTION__, __LINE__);
-+ ASSERT(NULL);
-+ }
-+ itohi(inode) = NULL;
-+ itohi2(inode) = NULL;
-+
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+ inode->i_version++;
-+#else
-+ inode->i_version = ++event; /* increment inode version */
-+#endif
-+ inode->i_op = &mini_fo_main_iops;
-+ inode->i_fop = &mini_fo_main_fops;
-+#if 0
-+ /*
-+ * XXX: To export a file system via NFS, it has to have the
-+ * FS_REQUIRES_DEV flag, so turn it on. But should we inherit it from
-+ * the lower file system, or can we allow our file system to be exported
-+ * even if the lower one cannot be natively exported.
-+ */
-+ inode->i_sb->s_type->fs_flags |= FS_REQUIRES_DEV;
-+ /*
-+ * OK, the above was a hack, which is now turned off because it may
-+ * cause a panic/oops on some systems. The correct way to export a
-+ * "nodev" filesystem is via using nfs-utils > 1.0 and the "fsid=" export
-+ * parameter, which requires 2.4.20 or later.
-+ */
-+#endif
-+ /* I don't think ->a_ops is ever allowed to be NULL */
-+ inode->i_mapping->a_ops = &mini_fo_empty_aops;
-+}
-+
-+
-+#if defined(FIST_DEBUG) || defined(FIST_FILTER_SCA)
-+/*
-+ * No need to call write_inode() on the lower inode, as it
-+ * will have been marked 'dirty' anyway. But we might need
-+ * to write some of our own stuff to disk.
-+ */
-+STATIC void
-+mini_fo_write_inode(inode_t *inode, int sync)
-+{
-+ print_entry_location();
-+ print_exit_location();
-+}
-+#endif /* defined(FIST_DEBUG) || defined(FIST_FILTER_SCA) */
-+
-+
-+STATIC void
-+mini_fo_put_inode(inode_t *inode)
-+{
-+ /*
-+ * This is really funky stuff:
-+ * Basically, if i_count == 1, iput will then decrement it and this inode will be destroyed.
-+ * It is currently holding a reference to the hidden inode.
-+ * Therefore, it needs to release that reference by calling iput on the hidden inode.
-+ * iput() _will_ do it for us (by calling our clear_inode), but _only_ if i_nlink == 0.
-+ * The problem is, NFS keeps i_nlink == 1 for silly_rename'd files.
-+ * So we must for our i_nlink to 0 here to trick iput() into calling our clear_inode.
-+ */
-+ if (atomic_read(&inode->i_count) == 1)
-+ inode->i_nlink = 0;
-+}
-+
-+
-+#if defined(FIST_DEBUG) || defined(FIST_FILTER_SCA)
-+/*
-+ * we now define delete_inode, because there are two VFS paths that may
-+ * destroy an inode: one of them calls clear inode before doing everything
-+ * else that's needed, and the other is fine. This way we truncate the inode
-+ * size (and its pages) and then clear our own inode, which will do an iput
-+ * on our and the lower inode.
-+ */
-+STATIC void
-+mini_fo_delete_inode(inode_t *inode)
-+{
-+ print_entry_location();
-+
-+ fist_checkinode(inode, "mini_fo_delete_inode IN");
-+ inode->i_size = 0; /* every f/s seems to do that */
-+ clear_inode(inode);
-+
-+ print_exit_location();
-+}
-+#endif /* defined(FIST_DEBUG) || defined(FIST_FILTER_SCA) */
-+
-+
-+/* final actions when unmounting a file system */
-+STATIC void
-+mini_fo_put_super(super_block_t *sb)
-+{
-+ if (stopd(sb)) {
-+ mntput(stopd(sb)->hidden_mnt);
-+ mntput(stopd(sb)->hidden_mnt2);
-+
-+ /* mk: no! dput(stopd(sb)->base_dir_dentry);
-+ dput(stopd(sb)->storage_dir_dentry); */
-+
-+ kfree(stopd(sb));
-+ __stopd(sb) = NULL;
-+ }
-+}
-+
-+
-+#ifdef NOT_NEEDED
-+/*
-+ * This is called in do_umount before put_super.
-+ * The superblock lock is not held yet.
-+ * We probably do not need to define this or call write_super
-+ * on the hidden_sb, because sync_supers() will get to hidden_sb
-+ * sooner or later. But it is also called from file_fsync()...
-+ */
-+STATIC void
-+mini_fo_write_super(super_block_t *sb)
-+{
-+ return;
-+}
-+#endif /* NOT_NEEDED */
-+
-+
-+STATIC int
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
-+mini_fo_statfs(struct dentry *d, struct kstatfs *buf)
-+#elif LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
-+mini_fo_statfs(super_block_t *sb, struct kstatfs *buf)
-+#else
-+mini_fo_statfs(super_block_t *sb, struct statfs *buf)
-+#endif
-+{
-+ int err = 0;
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
-+ struct dentry *hidden_d;
-+
-+ hidden_d = dtohd(d);
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36)
-+ err = statfs_by_dentry(hidden_d, buf);
-+#else
-+ err = vfs_statfs(hidden_d, buf);
-+#endif
-+#else
-+ super_block_t *hidden_sb;
-+
-+ hidden_sb = stohs(sb);
-+ err = vfs_statfs(hidden_sb, buf);
-+#endif
-+
-+ return err;
-+}
-+
-+
-+/*
-+ * XXX: not implemented. This is not allowed yet.
-+ * Should we call this on the hidden_sb? Probably not.
-+ */
-+STATIC int
-+mini_fo_remount_fs(super_block_t *sb, int *flags, char *data)
-+{
-+ //printk(KERN_CRIT "mini_fo_remount_fs: WARNING, this function is umimplemented.\n");
-+ return -ENOSYS;
-+}
-+
-+
-+/*
-+ * Called by iput() when the inode reference count reached zero
-+ * and the inode is not hashed anywhere. Used to clear anything
-+ * that needs to be, before the inode is completely destroyed and put
-+ * on the inode free list.
-+ */
-+STATIC void
-+mini_fo_clear_inode(inode_t *inode)
-+{
-+ /*
-+ * Decrement a reference to a hidden_inode, which was incremented
-+ * by our read_inode when it was created initially.
-+ */
-+
-+ /* release the wol_list */
-+ if(S_ISDIR(inode->i_mode)) {
-+ __meta_put_lists(inode);
-+ }
-+
-+ /* mk: fan out fun */
-+ if(itohi(inode))
-+ iput(itohi(inode));
-+ if(itohi2(inode))
-+ iput(itohi2(inode));
-+
-+ // XXX: why this assertion fails?
-+ // because it doesn't like us
-+ // ASSERT((inode->i_state & I_DIRTY) == 0);
-+ kfree(itopd(inode));
-+ __itopd(inode) = NULL;
-+}
-+
-+
-+/*
-+ * Called in do_umount() if the MNT_FORCE flag was used and this
-+ * function is defined. See comment in linux/fs/super.c:do_umount().
-+ * Used only in nfs, to kill any pending RPC tasks, so that subsequent
-+ * code can actually succeed and won't leave tasks that need handling.
-+ *
-+ * PS. I wonder if this is somehow useful to undo damage that was
-+ * left in the kernel after a user level file server (such as amd)
-+ * dies.
-+ */
-+STATIC void
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,18)
-+mini_fo_umount_begin(struct vfsmount *mnt, int flags)
-+{
-+ struct vfsmount *hidden_mnt;
-+
-+ hidden_mnt = stopd(mnt->mnt_sb)->hidden_mnt;
-+
-+ if (hidden_mnt->mnt_sb->s_op->umount_begin)
-+ hidden_mnt->mnt_sb->s_op->umount_begin(hidden_mnt, flags);
-+
-+}
-+#else
-+mini_fo_umount_begin(super_block_t *sb)
-+{
-+ super_block_t *hidden_sb;
-+
-+ hidden_sb = stohs(sb);
-+
-+ if (hidden_sb->s_op->umount_begin)
-+ hidden_sb->s_op->umount_begin(hidden_sb);
-+
-+}
-+#endif
-+
-+
-+struct super_operations mini_fo_sops =
-+{
-+ read_inode: mini_fo_read_inode,
-+#if defined(FIST_DEBUG) || defined(FIST_FILTER_SCA)
-+ write_inode: mini_fo_write_inode,
-+#endif /* defined(FIST_DEBUG) || defined(FIST_FILTER_SCA) */
-+ put_inode: mini_fo_put_inode,
-+#if defined(FIST_DEBUG) || defined(FIST_FILTER_SCA)
-+ delete_inode: mini_fo_delete_inode,
-+#endif /* defined(FIST_DEBUG) || defined(FIST_FILTER_SCA) */
-+ put_super: mini_fo_put_super,
-+ statfs: mini_fo_statfs,
-+ remount_fs: mini_fo_remount_fs,
-+ clear_inode: mini_fo_clear_inode,
-+ umount_begin: mini_fo_umount_begin,
-+};
---- /dev/null
-+++ b/fs/mini_fo/Kconfig
-@@ -0,0 +1,3 @@
-+config MINI_FO
-+ tristate "Mini fanout overlay filesystem"
-+
--- /dev/null
+--- /dev/null
++++ b/Documentation/filesystems/overlayfs.txt
+@@ -0,0 +1,163 @@
++Written by: Neil Brown <neilb@suse.de>
++
++Overlay Filesystem
++==================
++
++This document describes a prototype for a new approach to providing
++overlay-filesystem functionality in Linux (sometimes referred to as
++union-filesystems). An overlay-filesystem tries to present a
++filesystem which is the result over overlaying one filesystem on top
++of the other.
++
++The result will inevitably fail to look exactly like a normal
++filesystem for various technical reasons. The expectation is that
++many use cases will be able to ignore these differences.
++
++This approach is 'hybrid' because the objects that appear in the
++filesystem do not all appear to belong to that filesystem. In many
++case an object accessed in the union will be indistinguishable
++from accessing the corresponding object from the original filesystem.
++This is most obvious from the 'st_dev' field returned by stat(2).
++
++While directories will report an st_dev for the overlay-filesystem,
++all non-directory objects will report an st_dev whichever of the
++'lower' or 'upper' filesystem that is providing the object. Similarly
++st_ino will only be unique when combined with st_dev, and both of
++these can change over the lifetime of a non-directory object. Many
++applications and tools ignore these values and will not be affected.
++
++Upper and Lower
++---------------
++
++An overlay filesystem combines two filesystems - an 'upper' filesystem
++and a 'lower' filesystem. When a name exists in both filesystems, the
++object in the 'upper' filesystem is visible while the object in the
++'lower' filesystem is either hidden or, in the case of directories,
++merged with the 'upper' object.
++
++It would be more correct to refer to an upper and lower 'directory
++tree' rather than 'filesystem' as it is quite possible for both
++directory trees to be in the same filesystem and there is no
++requirement that the root of a filesystem be given for either upper or
++lower.
++
++The lower filesystem can be any filesystem supported by Linux and does
++not need to be writable. The lower filesystem can even be another
++overlayfs. The upper filesystem will normally be writable and if it
++is it must support the creation of trusted.* extended attributes, and
++must provide valid d_type in readdir responses, at least for symbolic
++links - so NFS is not suitable.
++
++A read-only overlay of two read-only filesystems may use any
++filesystem type.
++
++Directories
++-----------
++
++Overlaying mainly involved directories. If a given name appears in both
++upper and lower filesystems and refers to a non-directory in either,
++then the lower object is hidden - the name refers only to the upper
++object.
++
++Where both upper and lower objects are directories, a merged directory
++is formed.
++
++At mount time, the two directories given as mount options are combined
++into a merged directory. Then whenever a lookup is requested in such
++a merged directory, the lookup is performed in each actual directory
++and the combined result is cached in the dentry belonging to the overlay
++filesystem. If both actual lookups find directories, both are stored
++and a merged directory is created, otherwise only one is stored: the
++upper if it exists, else the lower.
++
++Only the lists of names from directories are merged. Other content
++such as metadata and extended attributes are reported for the upper
++directory only. These attributes of the lower directory are hidden.
++
++whiteouts and opaque directories
++--------------------------------
++
++In order to support rm and rmdir without changing the lower
++filesystem, an overlay filesystem needs to record in the upper filesystem
++that files have been removed. This is done using whiteouts and opaque
++directories (non-directories are always opaque).
++
++The overlay filesystem uses extended attributes with a
++"trusted.overlay." prefix to record these details.
++
++A whiteout is created as a symbolic link with target
++"(overlay-whiteout)" and with xattr "trusted.overlay.whiteout" set to "y".
++When a whiteout is found in the upper level of a merged directory, any
++matching name in the lower level is ignored, and the whiteout itself
++is also hidden.
++
++A directory is made opaque by setting the xattr "trusted.overlay.opaque"
++to "y". Where the upper filesystem contains an opaque directory, any
++directory in the lower filesystem with the same name is ignored.
++
++readdir
++-------
++
++When a 'readdir' request is made on a merged directory, the upper and
++lower directories are each read and the name lists merged in the
++obvious way (upper is read first, then lower - entries that already
++exist are not re-added). This merged name list is cached in the
++'struct file' and so remains as long as the file is kept open. If the
++directory is opened and read by two processes at the same time, they
++will each have separate caches. A seekdir to the start of the
++directory (offset 0) followed by a readdir will cause the cache to be
++discarded and rebuilt.
++
++This means that changes to the merged directory do not appear while a
++directory is being read. This is unlikely to be noticed by many
++programs.
++
++seek offsets are assigned sequentially when the directories are read.
++Thus if
++ - read part of a directory
++ - remember an offset, and close the directory
++ - re-open the directory some time later
++ - seek to the remembered offset
++
++there may be little correlation between the old and new locations in
++the list of filenames, particularly if anything has changed in the
++directory.
++
++Readdir on directories that are not merged is simply handled by the
++underlying directory (upper or lower).
++
++
++Non-directories
++---------------
++
++Objects that are not directories (files, symlinks, device-special
++files etc) are presented either from the upper or lower filesystem as
++appropriate. When a file in the lower filesystem is accessed in a way
++the requires write-access; such as opening for write access, changing
++some metadata etc, the file is first copied from the lower filesystem
++to the upper filesystem (copy_up). Note that creating a hard-link
++also requires copy-up, though of course creation of a symlink does
++not.
++
++The copy_up process first makes sure that the containing directory
++exists in the upper filesystem - creating it and any parents as
++necessary. It then creates the object with the same metadata (owner,
++mode, mtime, symlink-target etc) and then if the object is a file, the
++data is copied from the lower to the upper filesystem. Finally any
++extended attributes are copied up.
++
++Once the copy_up is complete, the overlay filesystem simply
++provides direct access to the newly created file in the upper
++filesystem - future operations on the file are barely noticed by the
++overlay filesystem (though an operation on the name of the file such as
++rename or unlink will of course be noticed and handled).
++
++Changes to underlying filesystems
++---------------------------------
++
++Offline changes, when the overlay is not mounted, are allowed to either
++the upper or the lower trees.
++
++Changes to the underlying filesystems while part of a mounted overlay
++filesystem are not allowed. This is not yet enforced, but will be in
++the future.
+--- a/fs/Kconfig
++++ b/fs/Kconfig
+@@ -63,6 +63,7 @@ source "fs/quota/Kconfig"
+
+ source "fs/autofs4/Kconfig"
+ source "fs/fuse/Kconfig"
++source "fs/overlayfs/Kconfig"
+
+ config CUSE
+ tristate "Character device in Userspace support"
+--- a/fs/Makefile
++++ b/fs/Makefile
+@@ -103,6 +103,7 @@ obj-$(CONFIG_QNX4FS_FS) += qnx4/
+ obj-$(CONFIG_AUTOFS4_FS) += autofs4/
+ obj-$(CONFIG_ADFS_FS) += adfs/
+ obj-$(CONFIG_FUSE_FS) += fuse/
++obj-$(CONFIG_OVERLAYFS_FS) += overlayfs/
+ obj-$(CONFIG_UDF_FS) += udf/
+ obj-$(CONFIG_SUN_OPENPROMFS) += openpromfs/
+ obj-$(CONFIG_OMFS_FS) += omfs/
+--- a/fs/namespace.c
++++ b/fs/namespace.c
+@@ -1451,6 +1451,23 @@ void drop_collected_mounts(struct vfsmou
+ release_mounts(&umount_list);
+ }
+
++struct vfsmount *clone_private_mount(struct path *path)
++{
++ struct vfsmount *mnt;
++
++ if (IS_MNT_UNBINDABLE(path->mnt))
++ return ERR_PTR(-EINVAL);
++
++ down_read(&namespace_sem);
++ mnt = clone_mnt(path->mnt, path->dentry, CL_PRIVATE);
++ up_read(&namespace_sem);
++ if (!mnt)
++ return ERR_PTR(-ENOMEM);
++
++ return mnt;
++}
++EXPORT_SYMBOL_GPL(clone_private_mount);
++
+ int iterate_mounts(int (*f)(struct vfsmount *, void *), void *arg,
+ struct vfsmount *root)
+ {
+--- a/fs/open.c
++++ b/fs/open.c
+@@ -664,19 +664,19 @@ static inline int __get_file_write_acces
+ return error;
+ }
+
+-static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
+- struct file *f,
++static struct file *__dentry_open(struct path *path, struct file *f,
+ int (*open)(struct inode *, struct file *),
+ const struct cred *cred)
+ {
+ struct inode *inode;
+ int error;
+
++ path_get(path);
+ f->f_mode = OPEN_FMODE(f->f_flags) | FMODE_LSEEK |
+ FMODE_PREAD | FMODE_PWRITE;
+- inode = dentry->d_inode;
++ inode = path->dentry->d_inode;
+ if (f->f_mode & FMODE_WRITE) {
+- error = __get_file_write_access(inode, mnt);
++ error = __get_file_write_access(inode, path->mnt);
+ if (error)
+ goto cleanup_file;
+ if (!special_file(inode->i_mode))
+@@ -684,8 +684,7 @@ static struct file *__dentry_open(struct
+ }
+
+ f->f_mapping = inode->i_mapping;
+- f->f_path.dentry = dentry;
+- f->f_path.mnt = mnt;
++ f->f_path = *path;
+ f->f_pos = 0;
+ f->f_op = fops_get(inode->i_fop);
+ file_sb_list_add(f, inode->i_sb);
+@@ -731,7 +730,7 @@ cleanup_all:
+ * here, so just reset the state.
+ */
+ file_reset_write(f);
+- mnt_drop_write(mnt);
++ mnt_drop_write(path->mnt);
+ }
+ }
+ file_sb_list_del(f);
+@@ -739,8 +738,7 @@ cleanup_all:
+ f->f_path.mnt = NULL;
+ cleanup_file:
+ put_filp(f);
+- dput(dentry);
+- mntput(mnt);
++ path_put(path);
+ return ERR_PTR(error);
+ }
+
+@@ -766,14 +764,14 @@ cleanup_file:
+ struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry,
+ int (*open)(struct inode *, struct file *))
+ {
++ struct path path = { .dentry = dentry, .mnt = nd->path.mnt };
+ const struct cred *cred = current_cred();
+
+ if (IS_ERR(nd->intent.open.file))
+ goto out;
+ if (IS_ERR(dentry))
+ goto out_err;
+- nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->path.mnt),
+- nd->intent.open.file,
++ nd->intent.open.file = __dentry_open(&path, nd->intent.open.file,
+ open, cred);
+ out:
+ return nd->intent.open.file;
+@@ -802,10 +800,17 @@ struct file *nameidata_to_filp(struct na
+
+ /* Has the filesystem initialised the file for us? */
+ if (filp->f_path.dentry == NULL) {
+- path_get(&nd->path);
+- filp = __dentry_open(nd->path.dentry, nd->path.mnt, filp,
+- NULL, cred);
++ struct inode *inode = nd->path.dentry->d_inode;
++
++ if (inode->i_op->open) {
++ int flags = filp->f_flags;
++ put_filp(filp);
++ filp = inode->i_op->open(nd->path.dentry, flags, cred);
++ } else {
++ filp = __dentry_open(&nd->path, filp, NULL, cred);
++ }
+ }
++
+ return filp;
+ }
+
+@@ -816,35 +821,45 @@ struct file *nameidata_to_filp(struct na
+ struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags,
+ const struct cred *cred)
+ {
+- int error;
++ struct path path = { .dentry = dentry, .mnt = mnt };
++ struct file *ret;
++
++ BUG_ON(!mnt);
++
++ ret = vfs_open(&path, flags, cred);
++ path_put(&path);
++
++ return ret;
++}
++EXPORT_SYMBOL(dentry_open);
++
++/**
++ * vfs_open - open the file at the given path
++ * @path: path to open
++ * @flags: open flags
++ * @cred: credentials to use
++ *
++ * Open the file. If successful, the returned file will have acquired
++ * an additional reference for path.
++ */
++struct file *vfs_open(struct path *path, int flags, const struct cred *cred)
++{
+ struct file *f;
++ struct inode *inode = path->dentry->d_inode;
+
+ validate_creds(cred);
+
+- /*
+- * We must always pass in a valid mount pointer. Historically
+- * callers got away with not passing it, but we must enforce this at
+- * the earliest possible point now to avoid strange problems deep in the
+- * filesystem stack.
+- */
+- if (!mnt) {
+- printk(KERN_WARNING "%s called with NULL vfsmount\n", __func__);
+- dump_stack();
+- return ERR_PTR(-EINVAL);
+- }
++ if (inode->i_op->open)
++ return inode->i_op->open(path->dentry, flags, cred);
+
+- error = -ENFILE;
+ f = get_empty_filp();
+- if (f == NULL) {
+- dput(dentry);
+- mntput(mnt);
+- return ERR_PTR(error);
+- }
++ if (f == NULL)
++ return ERR_PTR(-ENFILE);
+
+ f->f_flags = flags;
+- return __dentry_open(dentry, mnt, f, NULL, cred);
++ return __dentry_open(path, f, NULL, cred);
+ }
+-EXPORT_SYMBOL(dentry_open);
++EXPORT_SYMBOL(vfs_open);
+
+ static void __put_unused_fd(struct files_struct *files, unsigned int fd)
+ {
+--- /dev/null
++++ b/fs/overlayfs/Kconfig
+@@ -0,0 +1,4 @@
++config OVERLAYFS_FS
++ tristate "Overlay filesystem support"
++ help
++ Add support for overlay filesystem.
+--- /dev/null
++++ b/fs/overlayfs/Makefile
+@@ -0,0 +1,5 @@
++#
++# Makefile for the overlay filesystem.
++#
++
++obj-$(CONFIG_OVERLAYFS_FS) += overlayfs.o
+--- /dev/null
++++ b/fs/overlayfs/overlayfs.c
+@@ -0,0 +1,2358 @@
++#include <linux/fs.h>
++#include <linux/namei.h>
++#include <linux/sched.h>
++#include <linux/fs_struct.h>
++#include <linux/file.h>
++#include <linux/xattr.h>
++#include <linux/security.h>
++#include <linux/device_cgroup.h>
++#include <linux/mount.h>
++#include <linux/splice.h>
++#include <linux/slab.h>
++#include <linux/parser.h>
++#include <linux/module.h>
++#include <linux/uaccess.h>
++#include <linux/rbtree.h>
++
++MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
++MODULE_DESCRIPTION("Overlay filesystem");
++MODULE_LICENSE("GPL");
++
++#define OVL_COPY_UP_CHUNK_SIZE (1 << 20)
++
++struct ovl_fs {
++ struct vfsmount *upper_mnt;
++ struct vfsmount *lower_mnt;
++};
++
++struct ovl_entry {
++ struct dentry *__upperdentry;
++ struct dentry *lowerdentry;
++ union {
++ struct {
++ u64 version;
++ bool opaque;
++ };
++ struct rcu_head rcu;
++ };
++};
++
++static const char *ovl_whiteout_xattr = "trusted.overlay.whiteout";
++static const char *ovl_opaque_xattr = "trusted.overlay.opaque";
++static const char *ovl_whiteout_symlink = "(overlay-whiteout)";
++
++enum ovl_path_type {
++ OVL_PATH_UPPER,
++ OVL_PATH_MERGE,
++ OVL_PATH_LOWER,
++};
++
++static enum ovl_path_type ovl_path_type(struct dentry *dentry)
++{
++ struct ovl_entry *oe = dentry->d_fsdata;
++
++ if (oe->__upperdentry) {
++ if (oe->lowerdentry && S_ISDIR(dentry->d_inode->i_mode))
++ return OVL_PATH_MERGE;
++ else
++ return OVL_PATH_UPPER;
++ } else {
++ return OVL_PATH_LOWER;
++ }
++}
++
++static struct dentry *ovl_upperdentry_dereference(struct ovl_entry *oe)
++{
++ struct dentry *upperdentry = ACCESS_ONCE(oe->__upperdentry);
++ smp_read_barrier_depends();
++ return upperdentry;
++}
++
++static void ovl_path_upper(struct dentry *dentry, struct path *path)
++{
++ struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
++ struct ovl_entry *oe = dentry->d_fsdata;
++
++ path->mnt = ofs->upper_mnt;
++ path->dentry = ovl_upperdentry_dereference(oe);
++}
++
++static void ovl_path_lower(struct dentry *dentry, struct path *path)
++{
++ struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
++ struct ovl_entry *oe = dentry->d_fsdata;
++
++ path->mnt = ofs->lower_mnt;
++ path->dentry = oe->lowerdentry;
++}
++
++static enum ovl_path_type ovl_path_real(struct dentry *dentry,
++ struct path *path)
++{
++
++ enum ovl_path_type type = ovl_path_type(dentry);
++
++ if (type == OVL_PATH_LOWER)
++ ovl_path_lower(dentry, path);
++ else
++ ovl_path_upper(dentry, path);
++
++ return type;
++}
++
++static struct dentry *ovl_dentry_upper(struct dentry *dentry)
++{
++ struct ovl_entry *oe = dentry->d_fsdata;
++
++ return ovl_upperdentry_dereference(oe);
++}
++
++static struct dentry *ovl_dentry_lower(struct dentry *dentry)
++{
++ struct ovl_entry *oe = dentry->d_fsdata;
++
++ return oe->lowerdentry;
++}
++
++static struct dentry *ovl_dentry_real(struct dentry *dentry)
++{
++ struct ovl_entry *oe = dentry->d_fsdata;
++ struct dentry *realdentry;
++
++ realdentry = ovl_upperdentry_dereference(oe);
++ if (!realdentry)
++ realdentry = oe->lowerdentry;
++
++ return realdentry;
++}
++
++static bool ovl_dentry_is_opaque(struct dentry *dentry)
++{
++ struct ovl_entry *oe = dentry->d_fsdata;
++ return oe->opaque;
++}
++
++static void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque)
++{
++ struct ovl_entry *oe = dentry->d_fsdata;
++ oe->opaque = opaque;
++}
++
++static void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry)
++{
++ struct ovl_entry *oe = dentry->d_fsdata;
++
++ WARN_ON(!mutex_is_locked(&upperdentry->d_parent->d_inode->i_mutex));
++ WARN_ON(oe->__upperdentry);
++ smp_wmb();
++ oe->__upperdentry = upperdentry;
++}
++
++static void ovl_dentry_version_inc(struct dentry *dentry)
++{
++ struct ovl_entry *oe = dentry->d_fsdata;
++
++ WARN_ON(!mutex_is_locked(&dentry->d_inode->i_mutex));
++ oe->version++;
++}
++
++static u64 ovl_dentry_version_get(struct dentry *dentry)
++{
++ struct ovl_entry *oe = dentry->d_fsdata;
++
++ WARN_ON(!mutex_is_locked(&dentry->d_inode->i_mutex));
++ return oe->version;
++}
++
++static bool ovl_is_whiteout(struct dentry *dentry)
++{
++ int res;
++ char val;
++
++ if (!dentry)
++ return false;
++ if (!dentry->d_inode)
++ return false;
++ if (!S_ISLNK(dentry->d_inode->i_mode))
++ return false;
++
++ res = vfs_getxattr(dentry, ovl_whiteout_xattr, &val, 1);
++ if (res == 1 && val == 'y')
++ return true;
++
++ return false;
++}
++
++static bool ovl_is_opaquedir(struct dentry *dentry)
++{
++ int res;
++ char val;
++
++ if (!S_ISDIR(dentry->d_inode->i_mode))
++ return false;
++
++ res = vfs_getxattr(dentry, ovl_opaque_xattr, &val, 1);
++ if (res == 1 && val == 'y')
++ return true;
++
++ return false;
++}
++
++struct ovl_cache_entry {
++ const char *name;
++ unsigned int len;
++ unsigned int type;
++ u64 ino;
++ bool is_whiteout;
++ struct list_head l_node;
++ struct rb_node node;
++};
++
++struct ovl_readdir_data {
++ struct rb_root *root;
++ struct list_head *list;
++ struct list_head *middle;
++ struct dentry *dir;
++ int count;
++ int err;
++};
++
++struct ovl_dir_file {
++ bool is_real;
++ bool is_cached;
++ struct list_head cursor;
++ u64 cache_version;
++ struct list_head cache;
++ struct file *realfile;
++};
++
++static struct ovl_cache_entry *ovl_cache_entry_from_node(struct rb_node *n)
++{
++ return container_of(n, struct ovl_cache_entry, node);
++}
++
++static struct ovl_cache_entry *ovl_cache_entry_find(struct rb_root *root,
++ const char *name, int len)
++{
++ struct rb_node *node = root->rb_node;
++ int cmp;
++
++ while (node) {
++ struct ovl_cache_entry *p = ovl_cache_entry_from_node(node);
++
++ cmp = strncmp(name, p->name, len);
++ if (cmp > 0)
++ node = p->node.rb_right;
++ else if (cmp < 0 || len < p->len)
++ node = p->node.rb_left;
++ else
++ return p;
++ }
++
++ return NULL;
++}
++
++static struct ovl_cache_entry *ovl_cache_entry_new(const char *name, int len,
++ u64 ino, unsigned int d_type,
++ bool is_whiteout)
++{
++ struct ovl_cache_entry *p;
++
++ p = kmalloc(sizeof(*p) + len + 1, GFP_KERNEL);
++ if (p) {
++ char *name_copy = (char *) (p + 1);
++ memcpy(name_copy, name, len);
++ name_copy[len] = '\0';
++ p->name = name_copy;
++ p->len = len;
++ p->type = d_type;
++ p->ino = ino;
++ p->is_whiteout = is_whiteout;
++ }
++
++ return p;
++}
++
++static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd,
++ const char *name, int len, u64 ino,
++ unsigned int d_type, bool is_whiteout)
++{
++ struct rb_node **newp = &rdd->root->rb_node;
++ struct rb_node *parent = NULL;
++ struct ovl_cache_entry *p;
++
++ while (*newp) {
++ int cmp;
++ struct ovl_cache_entry *tmp;
++
++ parent = *newp;
++ tmp = ovl_cache_entry_from_node(*newp);
++ cmp = strncmp(name, tmp->name, len);
++ if (cmp > 0)
++ newp = &tmp->node.rb_right;
++ else if (cmp < 0 || len < tmp->len)
++ newp = &tmp->node.rb_left;
++ else
++ return 0;
++ }
++
++ p = ovl_cache_entry_new(name, len, ino, d_type, is_whiteout);
++ if (p == NULL)
++ return -ENOMEM;
++
++ list_add_tail(&p->l_node, rdd->list);
++ rb_link_node(&p->node, parent, newp);
++ rb_insert_color(&p->node, rdd->root);
++
++ return 0;
++}
++
++static int ovl_fill_lower(void *buf, const char *name, int namelen,
++ loff_t offset, u64 ino, unsigned int d_type)
++{
++ struct ovl_readdir_data *rdd = buf;
++ struct ovl_cache_entry *p;
++
++ rdd->count++;
++ p = ovl_cache_entry_find(rdd->root, name, namelen);
++ if (p) {
++ list_move_tail(&p->l_node, rdd->middle);
++ } else {
++ p = ovl_cache_entry_new(name, namelen, ino, d_type, false);
++ if (p == NULL)
++ rdd->err = -ENOMEM;
++ else
++ list_add_tail(&p->l_node, rdd->middle);
++ }
++
++ return rdd->err;
++}
++
++static void ovl_cache_free(struct list_head *list)
++{
++ struct ovl_cache_entry *p;
++ struct ovl_cache_entry *n;
++
++ list_for_each_entry_safe(p, n, list, l_node)
++ kfree(p);
++
++ INIT_LIST_HEAD(list);
++}
++
++static int ovl_fill_upper(void *buf, const char *name, int namelen,
++ loff_t offset, u64 ino, unsigned int d_type)
++{
++ struct ovl_readdir_data *rdd = buf;
++ bool is_whiteout = false;
++
++ rdd->count++;
++ if (d_type == DT_LNK) {
++ struct dentry *dentry;
++
++ dentry = lookup_one_len(name, rdd->dir, namelen);
++ if (IS_ERR(dentry)) {
++ rdd->err = PTR_ERR(dentry);
++ goto out;
++ }
++ is_whiteout = ovl_is_whiteout(dentry);
++ dput(dentry);
++ }
++
++ rdd->err = ovl_cache_entry_add_rb(rdd, name, namelen, ino, d_type,
++ is_whiteout);
++
++out:
++ return rdd->err;
++}
++
++static int ovl_dir_read(struct path *realpath, struct ovl_readdir_data *rdd,
++ filldir_t filler)
++{
++ const struct cred *old_cred;
++ struct cred *override_cred;
++ struct file *realfile;
++ int err;
++
++ realfile = vfs_open(realpath, O_RDONLY | O_DIRECTORY, current_cred());
++ if (IS_ERR(realfile))
++ return PTR_ERR(realfile);
++
++ err = -ENOMEM;
++ override_cred = prepare_creds();
++ if (override_cred) {
++ /*
++ * CAP_SYS_ADMIN for getxattr
++ * CAP_DAC_OVERRIDE for lookup and unlink
++ */
++ cap_raise(override_cred->cap_effective, CAP_SYS_ADMIN);
++ cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE);
++ old_cred = override_creds(override_cred);
++
++ do {
++ rdd->count = 0;
++ rdd->err = 0;
++ err = vfs_readdir(realfile, filler, rdd);
++ if (err >= 0)
++ err = rdd->err;
++ } while (!err && rdd->count);
++
++ revert_creds(old_cred);
++ put_cred(override_cred);
++ }
++ fput(realfile);
++
++ if (err) {
++ if (rdd->list)
++ ovl_cache_free(rdd->list);
++ return err;
++ }
++
++ return 0;
++}
++
++static void ovl_dir_reset(struct file *file)
++{
++ struct ovl_dir_file *od = file->private_data;
++ enum ovl_path_type type = ovl_path_type(file->f_path.dentry);
++
++ if (ovl_dentry_version_get(file->f_path.dentry) != od->cache_version) {
++ list_del_init(&od->cursor);
++ ovl_cache_free(&od->cache);
++ od->is_cached = false;
++ }
++ WARN_ON(!od->is_real && type != OVL_PATH_MERGE);
++ if (od->is_real && type == OVL_PATH_MERGE) {
++ fput(od->realfile);
++ od->realfile = NULL;
++ od->is_real = false;
++ }
++}
++
++static int ovl_dir_read_merged(struct path *upperpath, struct path *lowerpath,
++ struct ovl_readdir_data *rdd)
++{
++ int err;
++ struct rb_root root = RB_ROOT;
++ struct list_head middle;
++
++ rdd->root = &root;
++ if (upperpath->dentry) {
++ rdd->dir = upperpath->dentry;
++ err = ovl_dir_read(upperpath, rdd, ovl_fill_upper);
++ if (err)
++ goto out;
++ }
++ /*
++ * Insert lowerpath entries before upperpath ones, this allows
++ * offsets to be reasonably constant
++ */
++ list_add(&middle, rdd->list);
++ rdd->middle = &middle;
++ err = ovl_dir_read(lowerpath, rdd, ovl_fill_lower);
++ list_del(&middle);
++out:
++ rdd->root = NULL;
++
++ return err;
++}
++
++static void ovl_seek_cursor(struct ovl_dir_file *od, loff_t pos)
++{
++ struct list_head *l;
++ loff_t off;
++
++ l = od->cache.next;
++ for (off = 0; off < pos; off++) {
++ if (l == &od->cache)
++ break;
++ l = l->next;
++ }
++ list_move_tail(&od->cursor, l);
++}
++
++static int ovl_readdir(struct file *file, void *buf, filldir_t filler)
++{
++ struct ovl_dir_file *od = file->private_data;
++ int res;
++
++ if (!file->f_pos)
++ ovl_dir_reset(file);
++
++ if (od->is_real) {
++ res = vfs_readdir(od->realfile, filler, buf);
++ file->f_pos = od->realfile->f_pos;
++
++ return res;
++ }
++
++ if (!od->is_cached) {
++ struct path lowerpath;
++ struct path upperpath;
++ struct ovl_readdir_data rdd = { .list = &od->cache };
++
++ ovl_path_lower(file->f_path.dentry, &lowerpath);
++ ovl_path_upper(file->f_path.dentry, &upperpath);
++
++ res = ovl_dir_read_merged(&upperpath, &lowerpath, &rdd);
++ if (res)
++ return res;
++
++ od->cache_version = ovl_dentry_version_get(file->f_path.dentry);
++ od->is_cached = true;
++
++ ovl_seek_cursor(od, file->f_pos);
++ }
++
++ while (od->cursor.next != &od->cache) {
++ int over;
++ loff_t off;
++ struct ovl_cache_entry *p;
++
++ p = list_entry(od->cursor.next, struct ovl_cache_entry, l_node);
++ off = file->f_pos;
++ file->f_pos++;
++ list_move(&od->cursor, &p->l_node);
++
++ if (p->is_whiteout)
++ continue;
++
++ over = filler(buf, p->name, p->len, off, p->ino, p->type);
++ if (over)
++ break;
++ }
++
++ return 0;
++}
++
++static loff_t ovl_dir_llseek(struct file *file, loff_t offset, int origin)
++{
++ loff_t res;
++ struct ovl_dir_file *od = file->private_data;
++
++ mutex_lock(&file->f_dentry->d_inode->i_mutex);
++ if (!file->f_pos)
++ ovl_dir_reset(file);
++
++ if (od->is_real) {
++ res = vfs_llseek(od->realfile, offset, origin);
++ file->f_pos = od->realfile->f_pos;
++ } else {
++ res = -EINVAL;
++
++ switch (origin) {
++ case SEEK_CUR:
++ offset += file->f_pos;
++ break;
++ case SEEK_SET:
++ break;
++ default:
++ goto out_unlock;
++ }
++ if (offset < 0)
++ goto out_unlock;
++
++ if (offset != file->f_pos) {
++ file->f_pos = offset;
++ if (od->is_cached)
++ ovl_seek_cursor(od, offset);
++ }
++ res = offset;
++ }
++out_unlock:
++ mutex_unlock(&file->f_dentry->d_inode->i_mutex);
++
++ return res;
++}
++
++static int ovl_dir_fsync(struct file *file, int datasync)
++{
++ struct ovl_dir_file *od = file->private_data;
++
++ /* May need to reopen directory if it got copied up */
++ if (!od->realfile) {
++ struct path upperpath;
++
++ ovl_path_upper(file->f_path.dentry, &upperpath);
++ od->realfile = vfs_open(&upperpath, O_RDONLY, current_cred());
++ if (IS_ERR(od->realfile))
++ return PTR_ERR(od->realfile);
++ }
++
++ return vfs_fsync(od->realfile, datasync);
++}
++
++static int ovl_dir_release(struct inode *inode, struct file *file)
++{
++ struct ovl_dir_file *od = file->private_data;
++
++ list_del(&od->cursor);
++ ovl_cache_free(&od->cache);
++ if (od->realfile)
++ fput(od->realfile);
++ kfree(od);
++
++ return 0;
++}
++
++static int ovl_dir_open(struct inode *inode, struct file *file)
++{
++ struct path realpath;
++ struct file *realfile;
++ struct ovl_dir_file *od;
++ enum ovl_path_type type;
++
++ od = kzalloc(sizeof(struct ovl_dir_file), GFP_KERNEL);
++ if (!od)
++ return -ENOMEM;
++
++ type = ovl_path_real(file->f_path.dentry, &realpath);
++ realfile = vfs_open(&realpath, file->f_flags, current_cred());
++ if (IS_ERR(realfile)) {
++ kfree(od);
++ return PTR_ERR(realfile);
++ }
++ INIT_LIST_HEAD(&od->cache);
++ INIT_LIST_HEAD(&od->cursor);
++ od->is_cached = false;
++ od->realfile = realfile;
++ od->is_real = (type != OVL_PATH_MERGE);
++ file->private_data = od;
++
++ return 0;
++}
++
++static const struct file_operations ovl_dir_operations = {
++ .read = generic_read_dir,
++ .open = ovl_dir_open,
++ .readdir = ovl_readdir,
++ .llseek = ovl_dir_llseek,
++ .fsync = ovl_dir_fsync,
++ .release = ovl_dir_release,
++};
++
++static const struct inode_operations ovl_dir_inode_operations;
++
++static void ovl_entry_free(struct rcu_head *head)
++{
++ struct ovl_entry *oe = container_of(head, struct ovl_entry, rcu);
++ kfree(oe);
++}
++
++static void ovl_dentry_release(struct dentry *dentry)
++{
++ struct ovl_entry *oe = dentry->d_fsdata;
++
++ if (oe) {
++ dput(oe->__upperdentry);
++ dput(oe->lowerdentry);
++ call_rcu(&oe->rcu, ovl_entry_free);
++ }
++}
++
++static const struct dentry_operations ovl_dentry_operations = {
++ .d_release = ovl_dentry_release,
++};
++
++static struct dentry *ovl_lookup_real(struct dentry *dir, struct qstr *name)
++{
++ struct dentry *dentry;
++
++ mutex_lock(&dir->d_inode->i_mutex);
++ dentry = lookup_one_len(name->name, dir, name->len);
++ mutex_unlock(&dir->d_inode->i_mutex);
++
++ if (IS_ERR(dentry)) {
++ if (PTR_ERR(dentry) == -ENOENT)
++ dentry = NULL;
++ } else if (!dentry->d_inode) {
++ dput(dentry);
++ dentry = NULL;
++ }
++ return dentry;
++}
++
++static struct ovl_entry *ovl_alloc_entry(void)
++{
++ return kzalloc(sizeof(struct ovl_entry), GFP_KERNEL);
++}
++
++static struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
++ struct ovl_entry *oe);
++
++static struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
++ struct nameidata *nd)
++{
++ struct ovl_entry *oe;
++ struct dentry *upperdir;
++ struct dentry *lowerdir;
++ struct dentry *upperdentry = NULL;
++ struct dentry *lowerdentry = NULL;
++ struct inode *inode = NULL;
++ int err;
++
++ err = -ENOMEM;
++ oe = ovl_alloc_entry();
++ if (!oe)
++ goto out;
++
++ upperdir = ovl_dentry_upper(dentry->d_parent);
++ lowerdir = ovl_dentry_lower(dentry->d_parent);
++
++ if (upperdir) {
++ upperdentry = ovl_lookup_real(upperdir, &dentry->d_name);
++ err = PTR_ERR(upperdentry);
++ if (IS_ERR(upperdentry))
++ goto out_put_dir;
++
++ if (lowerdir && upperdentry &&
++ (S_ISLNK(upperdentry->d_inode->i_mode) ||
++ S_ISDIR(upperdentry->d_inode->i_mode))) {
++ const struct cred *old_cred;
++ struct cred *override_cred;
++
++ err = -ENOMEM;
++ override_cred = prepare_creds();
++ if (!override_cred)
++ goto out_dput_upper;
++
++ /* CAP_SYS_ADMIN needed for getxattr */
++ cap_raise(override_cred->cap_effective, CAP_SYS_ADMIN);
++ old_cred = override_creds(override_cred);
++
++ if (ovl_is_opaquedir(upperdentry)) {
++ oe->opaque = true;
++ } else if (ovl_is_whiteout(upperdentry)) {
++ dput(upperdentry);
++ upperdentry = NULL;
++ oe->opaque = true;
++ }
++ revert_creds(old_cred);
++ put_cred(override_cred);
++ }
++ }
++ if (lowerdir && !oe->opaque) {
++ lowerdentry = ovl_lookup_real(lowerdir, &dentry->d_name);
++ err = PTR_ERR(lowerdentry);
++ if (IS_ERR(lowerdentry))
++ goto out_dput_upper;
++ }
++
++ if (lowerdentry && upperdentry &&
++ (!S_ISDIR(upperdentry->d_inode->i_mode) ||
++ !S_ISDIR(lowerdentry->d_inode->i_mode))) {
++ dput(lowerdentry);
++ lowerdentry = NULL;
++ oe->opaque = true;
++ }
++
++ if (lowerdentry || upperdentry) {
++ struct dentry *realdentry;
++
++ realdentry = upperdentry ? upperdentry : lowerdentry;
++ err = -ENOMEM;
++ inode = ovl_new_inode(dir->i_sb, realdentry->d_inode->i_mode, oe);
++ if (!inode)
++ goto out_dput;
++ }
++
++ if (upperdentry)
++ oe->__upperdentry = upperdentry;
++
++ if (lowerdentry)
++ oe->lowerdentry = lowerdentry;
++
++ dentry->d_fsdata = oe;
++ dentry->d_op = &ovl_dentry_operations;
++ d_add(dentry, inode);
++
++ return NULL;
++
++out_dput:
++ dput(lowerdentry);
++out_dput_upper:
++ dput(upperdentry);
++out_put_dir:
++ kfree(oe);
++out:
++ return ERR_PTR(err);
++}
++
++static int ovl_copy_up_xattr(struct dentry *old, struct dentry *new)
++{
++ ssize_t list_size, size;
++ char *buf, *name, *value;
++ int error;
++
++ if (!old->d_inode->i_op->getxattr ||
++ !new->d_inode->i_op->getxattr)
++ return 0;
++
++ list_size = vfs_listxattr(old, NULL, 0);
++ if (list_size <= 0) {
++ if (list_size == -EOPNOTSUPP)
++ return 0;
++ return list_size;
++ }
++
++ buf = kzalloc(list_size, GFP_KERNEL);
++ if (!buf)
++ return -ENOMEM;
++
++ error = -ENOMEM;
++ value = kmalloc(XATTR_SIZE_MAX, GFP_KERNEL);
++ if (!value)
++ goto out;
++
++ list_size = vfs_listxattr(old, buf, list_size);
++ if (list_size <= 0) {
++ error = list_size;
++ goto out_free_value;
++ }
++
++ for (name = buf; name < (buf + list_size); name += strlen(name) + 1) {
++ size = vfs_getxattr(old, name, value, XATTR_SIZE_MAX);
++ if (size <= 0) {
++ error = size;
++ goto out_free_value;
++ }
++ error = vfs_setxattr(new, name, value, size, 0);
++ if (error)
++ goto out_free_value;
++ }
++
++out_free_value:
++ kfree(value);
++out:
++ kfree(buf);
++ return error;
++}
++
++static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len)
++{
++ struct file *old_file;
++ struct file *new_file;
++ int error = 0;
++
++ if (len == 0)
++ return 0;
++
++ old_file = vfs_open(old, O_RDONLY, current_cred());
++ if (IS_ERR(old_file))
++ return PTR_ERR(old_file);
++
++ new_file = vfs_open(new, O_WRONLY, current_cred());
++ if (IS_ERR(new_file)) {
++ error = PTR_ERR(new_file);
++ goto out_fput;
++ }
++
++ /* FIXME: copy up sparse files efficiently */
++ while (len) {
++ loff_t offset = new_file->f_pos;
++ size_t this_len = OVL_COPY_UP_CHUNK_SIZE;
++ long bytes;
++
++ if (len < this_len)
++ this_len = len;
++
++ if (signal_pending_state(TASK_KILLABLE, current))
++ return -EINTR;
++
++ bytes = do_splice_direct(old_file, &offset, new_file, this_len,
++ SPLICE_F_MOVE);
++ if (bytes <= 0) {
++ error = bytes;
++ break;
++ }
++
++ len -= bytes;
++ }
++
++ fput(new_file);
++out_fput:
++ fput(old_file);
++ return error;
++}
++
++static struct dentry *ovl_lookup_create(struct dentry *upperdir,
++ struct dentry *template)
++{
++ int err;
++ struct dentry *newdentry;
++ struct qstr *name = &template->d_name;
++
++ newdentry = lookup_one_len(name->name, upperdir, name->len);
++ if (IS_ERR(newdentry))
++ return newdentry;
++
++ if (newdentry->d_inode) {
++ const struct cred *old_cred;
++ struct cred *override_cred;
++
++ /* No need to check whiteout if lower parent is non-existent */
++ err = -EEXIST;
++ if (!ovl_dentry_lower(template->d_parent))
++ goto out_dput;
++
++ if (!S_ISLNK(newdentry->d_inode->i_mode))
++ goto out_dput;
++
++ err = -ENOMEM;
++ override_cred = prepare_creds();
++ if (!override_cred)
++ goto out_dput;
++
++ /*
++ * CAP_SYS_ADMIN for getxattr
++ * CAP_FOWNER for unlink in sticky directory
++ */
++ cap_raise(override_cred->cap_effective, CAP_SYS_ADMIN);
++ cap_raise(override_cred->cap_effective, CAP_FOWNER);
++ old_cred = override_creds(override_cred);
++
++ err = -EEXIST;
++ if (ovl_is_whiteout(newdentry))
++ err = vfs_unlink(upperdir->d_inode, newdentry);
++
++ revert_creds(old_cred);
++ put_cred(override_cred);
++ if (err)
++ goto out_dput;
++
++ dput(newdentry);
++ newdentry = lookup_one_len(name->name, upperdir, name->len);
++ if (IS_ERR(newdentry))
++ return newdentry;
++
++ /*
++ * Whiteout just been successfully removed, parent
++ * i_mutex is still held, there's no way the lookup
++ * could return positive.
++ */
++ WARN_ON(newdentry->d_inode);
++ }
++
++ return newdentry;
++
++out_dput:
++ dput(newdentry);
++ return ERR_PTR(err);
++}
++
++static struct dentry *ovl_upper_create(struct dentry *upperdir,
++ struct dentry *dentry,
++ struct kstat *stat, const char *link)
++{
++ int err;
++ struct dentry *newdentry;
++ struct inode *dir = upperdir->d_inode;
++
++ newdentry = ovl_lookup_create(upperdir, dentry);
++ if (IS_ERR(newdentry))
++ goto out;
++
++ switch (stat->mode & S_IFMT) {
++ case S_IFREG:
++ err = vfs_create(dir, newdentry, stat->mode, NULL);
++ break;
++
++ case S_IFDIR:
++ err = vfs_mkdir(dir, newdentry, stat->mode);
++ break;
++
++ case S_IFCHR:
++ case S_IFBLK:
++ case S_IFIFO:
++ case S_IFSOCK:
++ err = vfs_mknod(dir, newdentry, stat->mode, stat->rdev);
++ break;
++
++ case S_IFLNK:
++ err = vfs_symlink(dir, newdentry, link);
++ break;
++
++ default:
++ err = -EPERM;
++ }
++ if (err) {
++ dput(newdentry);
++ newdentry = ERR_PTR(err);
++ }
++
++out:
++ return newdentry;
++
++}
++
++static char *ovl_read_symlink(struct dentry *realdentry)
++{
++ int res;
++ char *buf;
++ struct inode *inode = realdentry->d_inode;
++ mm_segment_t old_fs;
++
++ res = -EINVAL;
++ if (!inode->i_op->readlink)
++ goto err;
++
++ res = -ENOMEM;
++ buf = (char *) __get_free_page(GFP_KERNEL);
++ if (!buf)
++ goto err;
++
++ old_fs = get_fs();
++ set_fs(get_ds());
++ /* The cast to a user pointer is valid due to the set_fs() */
++ res = inode->i_op->readlink(realdentry,
++ (char __user *)buf, PAGE_SIZE - 1);
++ set_fs(old_fs);
++ if (res < 0) {
++ free_page((unsigned long) buf);
++ goto err;
++ }
++ buf[res] = '\0';
++
++ return buf;
++
++err:
++ return ERR_PTR(res);
++}
++
++static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat)
++{
++ struct iattr attr = {
++ .ia_valid = ATTR_ATIME | ATTR_MTIME | ATTR_ATIME_SET | ATTR_MTIME_SET,
++ .ia_atime = stat->atime,
++ .ia_mtime = stat->mtime,
++ };
++
++ return notify_change(upperdentry, &attr);
++}
++
++static int ovl_set_mode(struct dentry *upperdentry, umode_t mode)
++{
++ struct iattr attr = {
++ .ia_valid = ATTR_MODE,
++ .ia_mode = mode,
++ };
++
++ return notify_change(upperdentry, &attr);
++}
++
++static int ovl_set_opaque(struct dentry *upperdentry)
++{
++ int err;
++ const struct cred *old_cred;
++ struct cred *override_cred;
++
++ override_cred = prepare_creds();
++ if (!override_cred)
++ return -ENOMEM;
++
++ /* CAP_SYS_ADMIN for setxattr of "trusted" namespace */
++ cap_raise(override_cred->cap_effective, CAP_SYS_ADMIN);
++ old_cred = override_creds(override_cred);
++ err = vfs_setxattr(upperdentry, ovl_opaque_xattr, "y", 1, 0);
++ revert_creds(old_cred);
++ put_cred(override_cred);
++
++ return err;
++}
++
++static int ovl_remove_opaque(struct dentry *upperdentry)
++{
++ int err;
++ const struct cred *old_cred;
++ struct cred *override_cred;
++
++ override_cred = prepare_creds();
++ if (!override_cred)
++ return -ENOMEM;
++
++ /* CAP_SYS_ADMIN for removexattr of "trusted" namespace */
++ cap_raise(override_cred->cap_effective, CAP_SYS_ADMIN);
++ old_cred = override_creds(override_cred);
++ err = vfs_removexattr(upperdentry, ovl_opaque_xattr);
++ revert_creds(old_cred);
++ put_cred(override_cred);
++
++ return err;
++}
++
++static int ovl_copy_up_locked(struct dentry *upperdir, struct dentry *dentry,
++ struct path *lowerpath, struct kstat *stat,
++ const char *link)
++{
++ int err;
++ struct path newpath;
++ umode_t mode = stat->mode;
++ struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
++
++ /* Can't properly set mode on creation because of the umask */
++ stat->mode &= S_IFMT;
++
++ newpath.mnt = ofs->upper_mnt;
++ newpath.dentry = ovl_upper_create(upperdir, dentry, stat, link);
++ if (IS_ERR(newpath.dentry)) {
++ err = PTR_ERR(newpath.dentry);
++
++ /* Already copied up? */
++ if (err == -EEXIST && ovl_path_type(dentry) != OVL_PATH_LOWER)
++ return 0;
++
++ return err;
++ }
++
++ /* FIXME: recovery from failure to copy up */
++
++ if (S_ISREG(stat->mode)) {
++ err = ovl_copy_up_data(lowerpath, &newpath, stat->size);
++ if (err)
++ return err;
++ }
++
++ err = ovl_copy_up_xattr(lowerpath->dentry, newpath.dentry);
++ if (err)
++ return err;
++
++ mutex_lock(&newpath.dentry->d_inode->i_mutex);
++ if (!S_ISLNK(stat->mode))
++ err = ovl_set_mode(newpath.dentry, mode);
++ if (!err)
++ err = ovl_set_timestamps(newpath.dentry, stat);
++ mutex_unlock(&newpath.dentry->d_inode->i_mutex);
++ if (err)
++ return err;
++
++ ovl_dentry_update(dentry, newpath.dentry);
++
++ /*
++ * Easiest way to get rid of the lower dentry reference is to
++ * drop this dentry. This is neither needed nor possible for
++ * directories.
++ */
++ if (!S_ISDIR(stat->mode))
++ d_drop(dentry);
++
++ return 0;
++}
++
++static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
++ struct path *lowerpath, struct kstat *stat)
++{
++ int err;
++ struct kstat pstat;
++ struct path parentpath;
++ struct dentry *upperdir;
++ const struct cred *old_cred;
++ struct cred *override_cred;
++ char *link = NULL;
++
++ ovl_path_upper(parent, &parentpath);
++ upperdir = parentpath.dentry;
++
++ err = vfs_getattr(parentpath.mnt, parentpath.dentry, &pstat);
++ if (err)
++ return err;
++
++ if (S_ISLNK(stat->mode)) {
++ link = ovl_read_symlink(lowerpath->dentry);
++ if (IS_ERR(link))
++ return PTR_ERR(link);
++ }
++
++ err = -ENOMEM;
++ override_cred = prepare_creds();
++ if (!override_cred)
++ goto out_free_link;
++
++ override_cred->fsuid = stat->uid;
++ override_cred->fsgid = stat->gid;
++ /*
++ * CAP_SYS_ADMIN for copying up extended attributes
++ * CAP_DAC_OVERRIDE for create
++ * CAP_FOWNER for chmod, timestamp update
++ * CAP_FSETID for chmod
++ * CAP_MKNOD for mknod
++ */
++ cap_raise(override_cred->cap_effective, CAP_SYS_ADMIN);
++ cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE);
++ cap_raise(override_cred->cap_effective, CAP_FOWNER);
++ cap_raise(override_cred->cap_effective, CAP_FSETID);
++ cap_raise(override_cred->cap_effective, CAP_MKNOD);
++ old_cred = override_creds(override_cred);
++
++ mutex_lock_nested(&upperdir->d_inode->i_mutex, I_MUTEX_PARENT);
++ /*
++ * Using upper filesystem locking to protect against copy up
++ * racing with rename (rename means the copy up was already
++ * successful).
++ */
++ if (dentry->d_parent != parent) {
++ WARN_ON((ovl_path_type(dentry) == OVL_PATH_LOWER));
++ err = 0;
++ } else {
++ err = ovl_copy_up_locked(upperdir, dentry, lowerpath,
++ stat, link);
++ if (!err) {
++ /* Restore timestamps on parent (best effort) */
++ ovl_set_timestamps(upperdir, &pstat);
++ }
++ }
++
++ mutex_unlock(&upperdir->d_inode->i_mutex);
++
++ revert_creds(old_cred);
++ put_cred(override_cred);
++
++out_free_link:
++ if (link)
++ free_page((unsigned long) link);
++
++ return err;
++}
++
++static int ovl_copy_up(struct dentry *dentry)
++{
++ int err;
++
++ err = 0;
++ while (!err) {
++ struct dentry *next;
++ struct dentry *parent;
++ struct path lowerpath;
++ struct kstat stat;
++ enum ovl_path_type type = ovl_path_type(dentry);
++
++ if (type != OVL_PATH_LOWER)
++ break;
++
++ next = dget(dentry);
++ /* find the topmost dentry not yet copied up */
++ for (;;) {
++ parent = dget_parent(next);
++
++ type = ovl_path_type(parent);
++ if (type != OVL_PATH_LOWER)
++ break;
++
++ dput(next);
++ next = parent;
++ }
++
++ ovl_path_lower(next, &lowerpath);
++ err = vfs_getattr(lowerpath.mnt, lowerpath.dentry, &stat);
++ if (!err)
++ err = ovl_copy_up_one(parent, next, &lowerpath, &stat);
++
++ dput(parent);
++ dput(next);
++ }
++
++ return err;
++}
++
++/* Optimize by not copying up the file first and truncating later */
++static int ovl_copy_up_truncate(struct dentry *dentry, loff_t size)
++{
++ int err;
++ struct kstat stat;
++ struct path lowerpath;
++ struct dentry *parent = dget_parent(dentry);
++
++ err = ovl_copy_up(parent);
++ if (err)
++ goto out_dput_parent;
++
++ ovl_path_lower(dentry, &lowerpath);
++ err = vfs_getattr(lowerpath.mnt, lowerpath.dentry, &stat);
++ if (err)
++ goto out_dput_parent;
++
++ if (size < stat.size)
++ stat.size = size;
++
++ err = ovl_copy_up_one(parent, dentry, &lowerpath, &stat);
++
++out_dput_parent:
++ dput(parent);
++ return err;
++}
++
++static int ovl_setattr(struct dentry *dentry, struct iattr *attr)
++{
++ struct dentry *upperdentry;
++ int err;
++
++ if ((attr->ia_valid & ATTR_SIZE) && !ovl_dentry_upper(dentry))
++ err = ovl_copy_up_truncate(dentry, attr->ia_size);
++ else
++ err = ovl_copy_up(dentry);
++ if (err)
++ return err;
++
++ upperdentry = ovl_dentry_upper(dentry);
++
++ if (attr->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID))
++ attr->ia_valid &= ~ATTR_MODE;
++
++ mutex_lock(&upperdentry->d_inode->i_mutex);
++ err = notify_change(upperdentry, attr);
++ mutex_unlock(&upperdentry->d_inode->i_mutex);
++
++ return err;
++}
++
++static int ovl_getattr(struct vfsmount *mnt, struct dentry *dentry,
++ struct kstat *stat)
++{
++ struct path realpath;
++
++ ovl_path_real(dentry, &realpath);
++ return vfs_getattr(realpath.mnt, realpath.dentry, stat);
++}
++
++static int ovl_dir_getattr(struct vfsmount *mnt, struct dentry *dentry,
++ struct kstat *stat)
++{
++ int err;
++ enum ovl_path_type type;
++ struct path realpath;
++
++ type = ovl_path_real(dentry, &realpath);
++ err = vfs_getattr(realpath.mnt, realpath.dentry, stat);
++ if (err)
++ return err;
++
++ stat->dev = dentry->d_sb->s_dev;
++ stat->ino = dentry->d_inode->i_ino;
++
++ /*
++ * It's probably not worth it to count subdirs to get the
++ * correct link count. nlink=1 seems to pacify 'find' and
++ * other utilities.
++ */
++ if (type == OVL_PATH_MERGE)
++ stat->nlink = 1;
++
++ return 0;
++}
++
++static int ovl_permission(struct inode *inode, int mask, unsigned int flags)
++{
++ struct ovl_entry *oe;
++ struct dentry *alias = NULL;
++ struct inode *realinode;
++ struct dentry *realdentry;
++ bool is_upper;
++ int err;
++
++ if (S_ISDIR(inode->i_mode)) {
++ oe = inode->i_private;
++ } else if (flags & IPERM_FLAG_RCU) {
++ return -ECHILD;
++ } else {
++ /*
++ * For non-directories find an alias and get the info
++ * from there.
++ */
++ spin_lock(&inode->i_lock);
++ if (WARN_ON(list_empty(&inode->i_dentry))) {
++ spin_unlock(&inode->i_lock);
++ return -ENOENT;
++ }
++ alias = list_entry(inode->i_dentry.next, struct dentry, d_alias);
++ dget(alias);
++ spin_unlock(&inode->i_lock);
++ oe = alias->d_fsdata;
++ }
++
++ realdentry = ovl_upperdentry_dereference(oe);
++ is_upper = true;
++ if (!realdentry) {
++ realdentry = oe->lowerdentry;
++ is_upper = false;
++ }
++
++ /* Careful in RCU walk mode */
++ realinode = ACCESS_ONCE(realdentry->d_inode);
++ if (!realinode) {
++ WARN_ON(!(flags & IPERM_FLAG_RCU));
++ return -ENOENT;
++ }
++
++ if (mask & MAY_WRITE) {
++ umode_t mode = realinode->i_mode;
++
++ /*
++ * Writes will always be redirected to upper layer, so
++ * ignore lower layer being read-only.
++ */
++ err = -EROFS;
++ if (is_upper && IS_RDONLY(realinode) &&
++ (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
++ goto out_dput;
++
++ /*
++ * Nobody gets write access to an immutable file.
++ */
++ err = -EACCES;
++ if (IS_IMMUTABLE(realinode))
++ goto out_dput;
++ }
++
++ if (realinode->i_op->permission)
++ err = realinode->i_op->permission(realinode, mask, flags);
++ else
++ err = generic_permission(realinode, mask, flags,
++ realinode->i_op->check_acl);
++out_dput:
++ dput(alias);
++ return err;
++}
++
++static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev,
++ const char *link)
++{
++ int err;
++ struct dentry *newdentry;
++ struct dentry *upperdir;
++ struct inode *inode;
++ struct kstat stat = {
++ .mode = mode,
++ .rdev = rdev,
++ };
++
++ err = -ENOMEM;
++ inode = ovl_new_inode(dentry->d_sb, mode, dentry->d_fsdata);
++ if (!inode)
++ goto out;
++
++ err = ovl_copy_up(dentry->d_parent);
++ if (err)
++ goto out_iput;
++
++ upperdir = ovl_dentry_upper(dentry->d_parent);
++ mutex_lock_nested(&upperdir->d_inode->i_mutex, I_MUTEX_PARENT);
++
++ newdentry = ovl_upper_create(upperdir, dentry, &stat, link);
++ err = PTR_ERR(newdentry);
++ if (IS_ERR(newdentry))
++ goto out_unlock;
++
++ ovl_dentry_version_inc(dentry->d_parent);
++ if (ovl_dentry_is_opaque(dentry) && S_ISDIR(mode)) {
++ err = ovl_set_opaque(newdentry);
++ if (err)
++ goto out_dput;
++ }
++ ovl_dentry_update(dentry, newdentry);
++ d_instantiate(dentry, inode);
++ inode = NULL;
++ newdentry = NULL;
++ err = 0;
++
++out_dput:
++ dput(newdentry);
++out_unlock:
++ mutex_unlock(&upperdir->d_inode->i_mutex);
++out_iput:
++ iput(inode);
++out:
++ return err;
++}
++
++static int ovl_create(struct inode *dir, struct dentry *dentry, int mode,
++ struct nameidata *nd)
++{
++ return ovl_create_object(dentry, (mode & 07777) | S_IFREG, 0, NULL);
++}
++
++static int ovl_mkdir(struct inode *dir, struct dentry *dentry, int mode)
++{
++ return ovl_create_object(dentry, (mode & 07777) | S_IFDIR, 0, NULL);
++}
++
++static int ovl_mknod(struct inode *dir, struct dentry *dentry, int mode,
++ dev_t rdev)
++{
++ return ovl_create_object(dentry, mode, rdev, NULL);
++}
++
++static int ovl_symlink(struct inode *dir, struct dentry *dentry,
++ const char *link)
++{
++ return ovl_create_object(dentry, S_IFLNK, 0, link);
++}
++
++struct ovl_link_data {
++ struct dentry *realdentry;
++ void *cookie;
++};
++
++static void *ovl_follow_link(struct dentry *dentry, struct nameidata *nd)
++{
++ void *ret;
++ struct dentry *realdentry;
++ struct inode *realinode;
++
++ realdentry = ovl_dentry_real(dentry);
++ realinode = realdentry->d_inode;
++
++ if (WARN_ON(!realinode->i_op->follow_link))
++ return ERR_PTR(-EPERM);
++
++ ret = realinode->i_op->follow_link(realdentry, nd);
++ if (IS_ERR(ret))
++ return ret;
++
++ if (realinode->i_op->put_link) {
++ struct ovl_link_data *data;
++
++ data = kmalloc(sizeof(struct ovl_link_data), GFP_KERNEL);
++ if (!data) {
++ realinode->i_op->put_link(realdentry, nd, ret);
++ return ERR_PTR(-ENOMEM);
++ }
++ data->realdentry = realdentry;
++ data->cookie = ret;
++
++ return data;
++ } else {
++ return NULL;
++ }
++}
++
++static void ovl_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
++{
++ struct inode *realinode;
++ struct ovl_link_data *data = c;
++
++ if (!data)
++ return;
++
++ realinode = data->realdentry->d_inode;
++ realinode->i_op->put_link(data->realdentry, nd, data->cookie);
++ kfree(data);
++}
++
++static int ovl_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
++{
++ struct path realpath;
++ struct inode *realinode;
++
++ ovl_path_real(dentry, &realpath);
++ realinode = realpath.dentry->d_inode;
++
++ if (!realinode->i_op->readlink)
++ return -EINVAL;
++
++ touch_atime(realpath.mnt, realpath.dentry);
++
++ return realinode->i_op->readlink(realpath.dentry, buf, bufsiz);
++}
++
++static int ovl_whiteout(struct dentry *upperdir, struct dentry *dentry)
++{
++ int err;
++ struct dentry *newdentry;
++ const struct cred *old_cred;
++ struct cred *override_cred;
++
++ /* FIXME: recheck lower dentry to see if whiteout is really needed */
++
++ err = -ENOMEM;
++ override_cred = prepare_creds();
++ if (!override_cred)
++ goto out;
++
++ /*
++ * CAP_SYS_ADMIN for setxattr
++ * CAP_DAC_OVERRIDE for symlink creation
++ */
++ cap_raise(override_cred->cap_effective, CAP_SYS_ADMIN);
++ cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE);
++ override_cred->fsuid = 0;
++ override_cred->fsgid = 0;
++ old_cred = override_creds(override_cred);
++
++ newdentry = lookup_one_len(dentry->d_name.name, upperdir,
++ dentry->d_name.len);
++ err = PTR_ERR(newdentry);
++ if (IS_ERR(newdentry))
++ goto out_put_cred;
++
++ /* Just been removed within the same locked region */
++ WARN_ON(newdentry->d_inode);
++
++ err = vfs_symlink(upperdir->d_inode, newdentry, ovl_whiteout_symlink);
++ if (err)
++ goto out_dput;
++
++ ovl_dentry_version_inc(dentry->d_parent);
++
++ err = vfs_setxattr(newdentry, ovl_whiteout_xattr, "y", 1, 0);
++
++out_dput:
++ dput(newdentry);
++out_put_cred:
++ revert_creds(old_cred);
++ put_cred(override_cred);
++out:
++ return err;
++}
++
++static int ovl_do_remove(struct dentry *dentry, bool is_dir)
++{
++ int err;
++ enum ovl_path_type type;
++ struct path realpath;
++ struct dentry *upperdir;
++
++ err = ovl_copy_up(dentry->d_parent);
++ if (err)
++ return err;
++
++ upperdir = ovl_dentry_upper(dentry->d_parent);
++ mutex_lock_nested(&upperdir->d_inode->i_mutex, I_MUTEX_PARENT);
++ type = ovl_path_real(dentry, &realpath);
++ if (type != OVL_PATH_LOWER) {
++ err = -ESTALE;
++ if (realpath.dentry->d_parent != upperdir)
++ goto out_d_drop;
++
++ if (is_dir)
++ err = vfs_rmdir(upperdir->d_inode, realpath.dentry);
++ else
++ err = vfs_unlink(upperdir->d_inode, realpath.dentry);
++ if (err)
++ goto out_d_drop;
++
++ ovl_dentry_version_inc(dentry->d_parent);
++ }
++
++ if (type != OVL_PATH_UPPER || ovl_dentry_is_opaque(dentry))
++ err = ovl_whiteout(upperdir, dentry);
++
++ /*
++ * Keeping this dentry hashed would mean having to release
++ * upperpath/lowerpath, which could only be done if we are the
++ * sole user of this dentry. Too tricky... Just unhash for
++ * now.
++ */
++out_d_drop:
++ d_drop(dentry);
++ mutex_unlock(&upperdir->d_inode->i_mutex);
++
++ return err;
++}
++
++static int ovl_unlink(struct inode *dir, struct dentry *dentry)
++{
++ return ovl_do_remove(dentry, false);
++}
++
++static int ovl_check_empty_dir(struct dentry *dentry)
++{
++ int err;
++ struct path lowerpath;
++ struct path upperpath;
++ struct ovl_cache_entry *p;
++ LIST_HEAD(list);
++ struct ovl_readdir_data rdd = { .list = &list };
++
++ ovl_path_upper(dentry, &upperpath);
++ ovl_path_lower(dentry, &lowerpath);
++
++ err = ovl_dir_read_merged(&upperpath, &lowerpath, &rdd);
++ if (err)
++ return err;
++
++ err = 0;
++
++ list_for_each_entry(p, &list, l_node) {
++ if (p->is_whiteout)
++ continue;
++
++ if (p->name[0] == '.') {
++ if (p->len == 1)
++ continue;
++ if (p->len == 2 && p->name[1] == '.')
++ continue;
++ }
++ err = -ENOTEMPTY;
++ break;
++ }
++
++ ovl_cache_free(&list);
++
++ return err;
++}
++
++static int ovl_unlink_whiteout(void *buf, const char *name, int namelen,
++ loff_t offset, u64 ino, unsigned int d_type)
++{
++ struct ovl_readdir_data *rdd = buf;
++
++ rdd->count++;
++ /* check d_type to filter out "." and ".." */
++ if (d_type == DT_LNK) {
++ struct dentry *dentry;
++
++ dentry = lookup_one_len(name, rdd->dir, namelen);
++ if (IS_ERR(dentry)) {
++ rdd->err = PTR_ERR(dentry);
++ } else {
++ rdd->err = vfs_unlink(rdd->dir->d_inode, dentry);
++ dput(dentry);
++ }
++ }
++
++ return rdd->err;
++}
++
++static int ovl_remove_whiteouts(struct dentry *dentry)
++{
++ struct path upperpath;
++ struct ovl_readdir_data rdd = { .list = NULL };
++
++ ovl_path_upper(dentry, &upperpath);
++ rdd.dir = upperpath.dentry;
++
++ return ovl_dir_read(&upperpath, &rdd, ovl_unlink_whiteout);
++}
++
++static int ovl_rmdir(struct inode *dir, struct dentry *dentry)
++{
++ int err;
++ enum ovl_path_type type;
++
++ type = ovl_path_type(dentry);
++ if (type != OVL_PATH_UPPER) {
++ err = ovl_check_empty_dir(dentry);
++ if (err)
++ return err;
++
++ if (type == OVL_PATH_MERGE) {
++ err = ovl_remove_whiteouts(dentry);
++ if (err)
++ return err;
++ }
++ }
++
++ return ovl_do_remove(dentry, true);
++}
++
++static int ovl_link(struct dentry *old, struct inode *newdir,
++ struct dentry *new)
++{
++ int err;
++ struct dentry *olddentry;
++ struct dentry *newdentry;
++ struct dentry *upperdir;
++
++ err = ovl_copy_up(old);
++ if (err)
++ goto out;
++
++ err = ovl_copy_up(new->d_parent);
++ if (err)
++ goto out;
++
++ upperdir = ovl_dentry_upper(new->d_parent);
++ mutex_lock_nested(&upperdir->d_inode->i_mutex, I_MUTEX_PARENT);
++ newdentry = ovl_lookup_create(upperdir, new);
++ err = PTR_ERR(newdentry);
++ if (IS_ERR(newdentry))
++ goto out_unlock;
++
++ olddentry = ovl_dentry_upper(old);
++ err = vfs_link(olddentry, upperdir->d_inode, newdentry);
++ if (!err) {
++ ovl_dentry_version_inc(new->d_parent);
++ ovl_dentry_update(new, newdentry);
++
++ ihold(old->d_inode);
++ d_instantiate(new, old->d_inode);
++ } else {
++ dput(newdentry);
++ }
++out_unlock:
++ mutex_unlock(&upperdir->d_inode->i_mutex);
++out:
++ return err;
++
++}
++
++static int ovl_rename(struct inode *olddir, struct dentry *old,
++ struct inode *newdir, struct dentry *new)
++{
++ int err;
++ enum ovl_path_type old_type;
++ struct dentry *old_upperdir;
++ struct dentry *new_upperdir;
++ struct dentry *olddentry;
++ struct dentry *newdentry;
++ struct dentry *trap;
++ bool is_dir = S_ISDIR(old->d_inode->i_mode);
++
++ /* Don't copy up directory trees */
++ old_type = ovl_path_type(old);
++ if (old_type != OVL_PATH_UPPER && is_dir)
++ return -EXDEV;
++
++ if (new->d_inode) {
++ enum ovl_path_type new_type;
++
++ new_type = ovl_path_type(new);
++
++ if (new_type == OVL_PATH_LOWER && old_type == OVL_PATH_LOWER) {
++ if (ovl_dentry_lower(old)->d_inode ==
++ ovl_dentry_lower(new)->d_inode)
++ return 0;
++ }
++ if (new_type != OVL_PATH_LOWER && old_type != OVL_PATH_LOWER) {
++ if (ovl_dentry_upper(old)->d_inode ==
++ ovl_dentry_upper(new)->d_inode)
++ return 0;
++ }
++
++ if (new_type != OVL_PATH_UPPER &&
++ S_ISDIR(new->d_inode->i_mode)) {
++ err = ovl_check_empty_dir(new);
++ if (err)
++ return err;
++
++ if (new_type == OVL_PATH_MERGE) {
++ err = ovl_remove_whiteouts(new);
++ if (err)
++ return err;
++ }
++ }
++ }
++
++ err = ovl_copy_up(old);
++ if (err)
++ return err;
++
++ err = ovl_copy_up(new->d_parent);
++ if (err)
++ return err;
++
++ old_upperdir = ovl_dentry_upper(old->d_parent);
++ new_upperdir = ovl_dentry_upper(new->d_parent);
++
++ trap = lock_rename(new_upperdir, old_upperdir);
++
++ olddentry = ovl_dentry_upper(old);
++ newdentry = ovl_dentry_upper(new);
++ if (newdentry) {
++ dget(newdentry);
++ } else {
++ newdentry = ovl_lookup_create(new_upperdir, new);
++ err = PTR_ERR(newdentry);
++ if (IS_ERR(newdentry))
++ goto out_unlock;
++ }
++
++ err = -ESTALE;
++ if (olddentry->d_parent != old_upperdir)
++ goto out_dput;
++ if (newdentry->d_parent != new_upperdir)
++ goto out_dput;
++ if (olddentry == trap)
++ goto out_dput;
++ if (newdentry == trap)
++ goto out_dput;
++
++ err = vfs_rename(old_upperdir->d_inode, olddentry,
++ new_upperdir->d_inode, newdentry);
++
++ if (!err) {
++ bool old_opaque = ovl_dentry_is_opaque(old);
++ bool new_opaque = ovl_dentry_is_opaque(new);
++
++ if (ovl_path_type(new) != OVL_PATH_UPPER)
++ new_opaque = true;
++
++ if (old_type != OVL_PATH_UPPER || old_opaque)
++ err = ovl_whiteout(old_upperdir, old);
++ if (!err && is_dir) {
++ if (old_opaque && !new_opaque) {
++ ovl_remove_opaque(olddentry);
++ ovl_dentry_set_opaque(old, false);
++ }
++ if (!old_opaque && new_opaque) {
++ err = ovl_set_opaque(olddentry);
++ ovl_dentry_set_opaque(old, true);
++ }
++ }
++ ovl_dentry_version_inc(old->d_parent);
++ ovl_dentry_version_inc(new->d_parent);
++ }
++
++out_dput:
++ dput(newdentry);
++out_unlock:
++ unlock_rename(new_upperdir, old_upperdir);
++ return err;
++}
++
++static bool ovl_is_private_xattr(const char *name)
++{
++ return strncmp(name, "trusted.overlay.", 14) == 0;
++}
++
++static int ovl_setxattr(struct dentry *dentry, const char *name,
++ const void *value, size_t size, int flags)
++{
++ int err;
++ struct dentry *upperdentry;
++
++ if (ovl_is_private_xattr(name))
++ return -EPERM;
++
++ err = ovl_copy_up(dentry);
++ if (err)
++ return err;
++
++ upperdentry = ovl_dentry_upper(dentry);
++ return vfs_setxattr(upperdentry, name, value, size, flags);
++}
++
++static ssize_t ovl_getxattr(struct dentry *dentry, const char *name,
++ void *value, size_t size)
++{
++ if (ovl_path_type(dentry->d_parent) == OVL_PATH_MERGE &&
++ ovl_is_private_xattr(name))
++ return -ENODATA;
++
++ return vfs_getxattr(ovl_dentry_real(dentry), name, value, size);
++}
++
++static ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
++{
++ ssize_t res;
++ int off;
++
++ res = vfs_listxattr(ovl_dentry_real(dentry), list, size);
++ if (res <= 0 || size == 0)
++ return res;
++
++ if (ovl_path_type(dentry->d_parent) != OVL_PATH_MERGE)
++ return res;
++
++ /* filter out private xattrs */
++ for (off = 0; off < res;) {
++ char *s = list + off;
++ size_t slen = strlen(s) + 1;
++
++ BUG_ON(off + slen > res);
++
++ if (ovl_is_private_xattr(s)) {
++ res -= slen;
++ memmove(s, s + slen, res - off);
++ } else {
++ off += slen;
++ }
++ }
++
++ return res;
++}
++
++static int ovl_removexattr(struct dentry *dentry, const char *name)
++{
++ int err;
++ struct path realpath;
++ enum ovl_path_type type;
++
++ if (ovl_path_type(dentry->d_parent) == OVL_PATH_MERGE &&
++ ovl_is_private_xattr(name))
++ return -ENODATA;
++
++ type = ovl_path_real(dentry, &realpath);
++ if (type == OVL_PATH_LOWER) {
++ err = vfs_getxattr(realpath.dentry, name, NULL, 0);
++ if (err < 0)
++ return err;
++
++ err = ovl_copy_up(dentry);
++ if (err)
++ return err;
++
++ ovl_path_upper(dentry, &realpath);
++ }
++
++ return vfs_removexattr(realpath.dentry, name);
++}
++
++static bool ovl_open_need_copy_up(int flags, enum ovl_path_type type,
++ struct dentry *realdentry)
++{
++ if (type != OVL_PATH_LOWER)
++ return false;
++
++ if (special_file(realdentry->d_inode->i_mode))
++ return false;
++
++ if (!(OPEN_FMODE(flags) & FMODE_WRITE) && !(flags & O_TRUNC))
++ return false;
++
++ return true;
++}
++
++static struct file *ovl_open(struct dentry *dentry, int flags,
++ const struct cred *cred)
++{
++ int err;
++ struct path realpath;
++ enum ovl_path_type type;
++
++ type = ovl_path_real(dentry, &realpath);
++ if (ovl_open_need_copy_up(flags, type, realpath.dentry)) {
++ if (flags & O_TRUNC)
++ err = ovl_copy_up_truncate(dentry, 0);
++ else
++ err = ovl_copy_up(dentry);
++ if (err)
++ return ERR_PTR(err);
++
++ ovl_path_upper(dentry, &realpath);
++ }
++
++ return vfs_open(&realpath, flags, cred);
++}
++
++static const struct inode_operations ovl_dir_inode_operations = {
++ .lookup = ovl_lookup,
++ .mkdir = ovl_mkdir,
++ .symlink = ovl_symlink,
++ .unlink = ovl_unlink,
++ .rmdir = ovl_rmdir,
++ .rename = ovl_rename,
++ .link = ovl_link,
++ .setattr = ovl_setattr,
++ .create = ovl_create,
++ .mknod = ovl_mknod,
++ .permission = ovl_permission,
++ .getattr = ovl_dir_getattr,
++ .setxattr = ovl_setxattr,
++ .getxattr = ovl_getxattr,
++ .listxattr = ovl_listxattr,
++ .removexattr = ovl_removexattr,
++};
++
++static const struct inode_operations ovl_file_inode_operations = {
++ .setattr = ovl_setattr,
++ .permission = ovl_permission,
++ .getattr = ovl_getattr,
++ .setxattr = ovl_setxattr,
++ .getxattr = ovl_getxattr,
++ .listxattr = ovl_listxattr,
++ .removexattr = ovl_removexattr,
++ .open = ovl_open,
++};
++
++static const struct inode_operations ovl_symlink_inode_operations = {
++ .setattr = ovl_setattr,
++ .follow_link = ovl_follow_link,
++ .put_link = ovl_put_link,
++ .readlink = ovl_readlink,
++ .getattr = ovl_getattr,
++ .setxattr = ovl_setxattr,
++ .getxattr = ovl_getxattr,
++ .listxattr = ovl_listxattr,
++ .removexattr = ovl_removexattr,
++};
++
++static struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
++ struct ovl_entry *oe)
++{
++ struct inode *inode;
++
++ inode = new_inode(sb);
++ if (!inode)
++ return NULL;
++
++ mode &= S_IFMT;
++
++ inode->i_ino = get_next_ino();
++ inode->i_mode = mode;
++ inode->i_flags |= S_NOATIME | S_NOCMTIME;
++
++ switch (mode) {
++ case S_IFDIR:
++ inode->i_private = oe;
++ inode->i_op = &ovl_dir_inode_operations;
++ inode->i_fop = &ovl_dir_operations;
++ break;
++
++ case S_IFLNK:
++ inode->i_op = &ovl_symlink_inode_operations;
++ break;
++
++ case S_IFREG:
++ case S_IFSOCK:
++ case S_IFBLK:
++ case S_IFCHR:
++ case S_IFIFO:
++ inode->i_op = &ovl_file_inode_operations;
++ break;
++
++ default:
++ WARN(1, "illegal file type: %i\n", mode);
++ inode = NULL;
++ }
++
++ return inode;
++
++}
++
++static void ovl_put_super(struct super_block *sb)
++{
++ struct ovl_fs *ufs = sb->s_fs_info;
++
++ if (!(sb->s_flags & MS_RDONLY))
++ mnt_drop_write(ufs->upper_mnt);
++
++ mntput(ufs->upper_mnt);
++ mntput(ufs->lower_mnt);
++
++ kfree(ufs);
++}
++
++static int ovl_remount_fs(struct super_block *sb, int *flagsp, char *data)
++{
++ int flags = *flagsp;
++ struct ovl_fs *ufs = sb->s_fs_info;
++
++ /* When remounting rw or ro, we need to adjust the write access to the
++ * upper fs.
++ */
++ if (((flags ^ sb->s_flags) & MS_RDONLY) == 0)
++ /* No change to readonly status */
++ return 0;
++
++ if (flags & MS_RDONLY) {
++ mnt_drop_write(ufs->upper_mnt);
++ return 0;
++ } else
++ return mnt_want_write(ufs->upper_mnt);
++}
++
++/**
++ * ovl_statfs
++ * @sb: The overlayfs super block
++ * @buf: The struct kstatfs to fill in with stats
++ *
++ * Get the filesystem statistics. As writes always target the upper layer
++ * filesystem pass the statfs to the same filesystem.
++ */
++static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf)
++{
++ struct dentry *root_dentry = dentry->d_sb->s_root;
++ struct path path;
++ ovl_path_upper(root_dentry, &path);
++
++ if (!path.dentry->d_sb->s_op->statfs)
++ return -ENOSYS;
++ return path.dentry->d_sb->s_op->statfs(path.dentry, buf);
++}
++
++static const struct super_operations ovl_super_operations = {
++ .put_super = ovl_put_super,
++ .remount_fs = ovl_remount_fs,
++ .statfs = ovl_statfs,
++};
++
++struct ovl_config {
++ char *lowerdir;
++ char *upperdir;
++};
++
++enum {
++ Opt_lowerdir,
++ Opt_upperdir,
++ Opt_err,
++};
++
++static const match_table_t ovl_tokens = {
++ {Opt_lowerdir, "lowerdir=%s"},
++ {Opt_upperdir, "upperdir=%s"},
++ {Opt_err, NULL}
++};
++
++static int ovl_parse_opt(char *opt, struct ovl_config *config)
++{
++ char *p;
++
++ config->upperdir = NULL;
++ config->lowerdir = NULL;
++
++ while ((p = strsep(&opt, ",")) != NULL) {
++ int token;
++ substring_t args[MAX_OPT_ARGS];
++
++ if (!*p)
++ continue;
++
++ token = match_token(p, ovl_tokens, args);
++ switch (token) {
++ case Opt_upperdir:
++ kfree(config->upperdir);
++ config->upperdir = match_strdup(&args[0]);
++ if (!config->upperdir)
++ return -ENOMEM;
++ break;
++
++ case Opt_lowerdir:
++ kfree(config->lowerdir);
++ config->lowerdir = match_strdup(&args[0]);
++ if (!config->lowerdir)
++ return -ENOMEM;
++ break;
++
++ default:
++ return -EINVAL;
++ }
++ }
++ return 0;
++}
++
++static int ovl_fill_super(struct super_block *sb, void *data, int silent)
++{
++ struct path lowerpath;
++ struct path upperpath;
++ struct inode *root_inode;
++ struct dentry *root_dentry;
++ struct ovl_entry *oe;
++ struct ovl_fs *ufs;
++ struct ovl_config config;
++ int err;
++
++ err = ovl_parse_opt((char *) data, &config);
++ if (err)
++ goto out;
++
++ err = -EINVAL;
++ if (!config.upperdir || !config.lowerdir) {
++ printk(KERN_ERR "overlayfs: missing upperdir or lowerdir\n");
++ goto out_free_config;
++ }
++
++ err = -ENOMEM;
++ ufs = kmalloc(sizeof(struct ovl_fs), GFP_KERNEL);
++ if (!ufs)
++ goto out_free_config;
++
++ oe = ovl_alloc_entry();
++ if (oe == NULL)
++ goto out_free_ufs;
++
++ root_inode = ovl_new_inode(sb, S_IFDIR, oe);
++ if (!root_inode)
++ goto out_free_oe;
++
++ err = kern_path(config.upperdir, LOOKUP_FOLLOW, &upperpath);
++ if (err)
++ goto out_put_root;
++
++ err = kern_path(config.lowerdir, LOOKUP_FOLLOW, &lowerpath);
++ if (err)
++ goto out_put_upperpath;
++
++ err = -ENOTDIR;
++ if (!S_ISDIR(upperpath.dentry->d_inode->i_mode) ||
++ !S_ISDIR(lowerpath.dentry->d_inode->i_mode))
++ goto out_put_lowerpath;
++
++ ufs->upper_mnt = clone_private_mount(&upperpath);
++ err = PTR_ERR(ufs->upper_mnt);
++ if (IS_ERR(ufs->upper_mnt)) {
++ printk(KERN_ERR "overlayfs: failed to clone upperpath\n");
++ goto out_put_lowerpath;
++ }
++
++ ufs->lower_mnt = clone_private_mount(&lowerpath);
++ err = PTR_ERR(ufs->lower_mnt);
++ if (IS_ERR(ufs->lower_mnt)) {
++ printk(KERN_ERR "overlayfs: failed to clone lowerpath\n");
++ goto out_put_upper_mnt;
++ }
++
++ if (!(sb->s_flags & MS_RDONLY)) {
++ err = mnt_want_write(ufs->upper_mnt);
++ if (err)
++ goto out_put_lower_mnt;
++ }
++
++ err = -ENOMEM;
++ root_dentry = d_alloc_root(root_inode);
++ if (!root_dentry)
++ goto out_drop_write;
++
++ mntput(upperpath.mnt);
++ mntput(lowerpath.mnt);
++
++ oe->__upperdentry = upperpath.dentry;
++ oe->lowerdentry = lowerpath.dentry;
++
++ root_dentry->d_fsdata = oe;
++ root_dentry->d_op = &ovl_dentry_operations;
++
++ sb->s_op = &ovl_super_operations;
++ sb->s_root = root_dentry;
++ sb->s_fs_info = ufs;
++
++ return 0;
++
++out_drop_write:
++ if (!(sb->s_flags & MS_RDONLY))
++ mnt_drop_write(ufs->upper_mnt);
++out_put_lower_mnt:
++ mntput(ufs->lower_mnt);
++out_put_upper_mnt:
++ mntput(ufs->upper_mnt);
++out_put_lowerpath:
++ path_put(&lowerpath);
++out_put_upperpath:
++ path_put(&upperpath);
++out_put_root:
++ iput(root_inode);
++out_free_oe:
++ kfree(oe);
++out_free_ufs:
++ kfree(ufs);
++out_free_config:
++ kfree(config.lowerdir);
++ kfree(config.upperdir);
++out:
++ return err;
++}
++
++static int ovl_get_sb(struct file_system_type *fs_type,
++ int flags, const char *dev_name,
++ void *raw_data, struct vfsmount *mnt)
++{
++ return get_sb_nodev(fs_type, flags, raw_data, ovl_fill_super, mnt);
++}
++
++static struct file_system_type ovl_fs_type = {
++ .owner = THIS_MODULE,
++ .name = "overlayfs",
++ .get_sb = ovl_get_sb,
++ .kill_sb = kill_anon_super,
++};
++
++static int __init ovl_init(void)
++{
++ return register_filesystem(&ovl_fs_type);
++}
++
++static void __exit ovl_exit(void)
++{
++ unregister_filesystem(&ovl_fs_type);
++}
++
++module_init(ovl_init);
++module_exit(ovl_exit);
+--- a/fs/splice.c
++++ b/fs/splice.c
+@@ -1296,6 +1296,7 @@ long do_splice_direct(struct file *in, l
+
+ return ret;
+ }
++EXPORT_SYMBOL(do_splice_direct);
+
+ static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
+ struct pipe_inode_info *opipe,
+--- a/include/linux/fs.h
++++ b/include/linux/fs.h
+@@ -1587,6 +1587,7 @@ struct inode_operations {
+ void (*truncate_range)(struct inode *, loff_t, loff_t);
+ int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
+ u64 len);
++ struct file *(*open)(struct dentry *, int flags, const struct cred *);
+ } ____cacheline_aligned;
+
+ struct seq_file;
+@@ -1990,6 +1991,7 @@ extern int do_fallocate(struct file *fil
+ extern long do_sys_open(int dfd, const char __user *filename, int flags,
+ int mode);
+ extern struct file *filp_open(const char *, int, int);
++extern struct file *vfs_open(struct path *, int flags, const struct cred *);
+ extern struct file * dentry_open(struct dentry *, struct vfsmount *, int,
+ const struct cred *);
+ extern int filp_close(struct file *, fl_owner_t id);
+--- a/include/linux/mount.h
++++ b/include/linux/mount.h
+@@ -100,6 +100,9 @@ extern void mnt_pin(struct vfsmount *mnt
+ extern void mnt_unpin(struct vfsmount *mnt);
+ extern int __mnt_is_readonly(struct vfsmount *mnt);
+
++struct path;
++extern struct vfsmount *clone_private_mount(struct path *path);
++
+ extern struct vfsmount *do_kern_mount(const char *fstype, int flags,
+ const char *name, void *data);
+
projects / openwrt / staging / rmilecki.git / commitdiff