--- /dev/null
+/*
+ * super.c - NILFS module and super block management.
+ *
+ * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Written by Ryusuke Konishi <ryusuke@osrg.net>
+ */
+/*
+ * linux/fs/ext2/super.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ * from
+ *
+ * linux/fs/minix/inode.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * Big-endian to little-endian byte-swapping/bitmaps by
+ * David S. Miller (davem@caip.rutgers.edu), 1995
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/parser.h>
+#include <linux/random.h>
+#include <linux/crc32.h>
+#include <linux/smp_lock.h>
+#include <linux/vfs.h>
+#include <linux/writeback.h>
+#include <linux/kobject.h>
+#include <linux/exportfs.h>
+#include "nilfs.h"
+#include "mdt.h"
+#include "alloc.h"
+#include "page.h"
+#include "cpfile.h"
+#include "ifile.h"
+#include "dat.h"
+#include "segment.h"
+#include "segbuf.h"
+
+MODULE_AUTHOR("NTT Corp.");
+MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
+ "(NILFS)");
+MODULE_VERSION(NILFS_VERSION);
+MODULE_LICENSE("GPL");
+
+static int nilfs_remount(struct super_block *sb, int *flags, char *data);
+static int test_exclusive_mount(struct file_system_type *fs_type,
+ struct block_device *bdev, int flags);
+
+/**
+ * nilfs_error() - report failure condition on a filesystem
+ *
+ * nilfs_error() sets an ERROR_FS flag on the superblock as well as
+ * reporting an error message. It should be called when NILFS detects
+ * incoherences or defects of meta data on disk. As for sustainable
+ * errors such as a single-shot I/O error, nilfs_warning() or the printk()
+ * function should be used instead.
+ *
+ * The segment constructor must not call this function because it can
+ * kill itself.
+ */
+void nilfs_error(struct super_block *sb, const char *function,
+ const char *fmt, ...)
+{
+ struct nilfs_sb_info *sbi = NILFS_SB(sb);
+ va_list args;
+
+ va_start(args, fmt);
+ printk(KERN_CRIT "NILFS error (device %s): %s: ", sb->s_id, function);
+ vprintk(fmt, args);
+ printk("\n");
+ va_end(args);
+
+ if (!(sb->s_flags & MS_RDONLY)) {
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+
+ if (!nilfs_test_opt(sbi, ERRORS_CONT))
+ nilfs_detach_segment_constructor(sbi);
+
+ down_write(&nilfs->ns_sem);
+ if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) {
+ nilfs->ns_mount_state |= NILFS_ERROR_FS;
+ nilfs->ns_sbp->s_state |= cpu_to_le16(NILFS_ERROR_FS);
+ nilfs_commit_super(sbi);
+ }
+ up_write(&nilfs->ns_sem);
+
+ if (nilfs_test_opt(sbi, ERRORS_RO)) {
+ printk(KERN_CRIT "Remounting filesystem read-only\n");
+ sb->s_flags |= MS_RDONLY;
+ }
+ }
+
+ if (nilfs_test_opt(sbi, ERRORS_PANIC))
+ panic("NILFS (device %s): panic forced after error\n",
+ sb->s_id);
+}
+
+void nilfs_warning(struct super_block *sb, const char *function,
+ const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ printk(KERN_WARNING "NILFS warning (device %s): %s: ",
+ sb->s_id, function);
+ vprintk(fmt, args);
+ printk("\n");
+ va_end(args);
+}
+
+static struct kmem_cache *nilfs_inode_cachep;
+
+struct inode *nilfs_alloc_inode(struct super_block *sb)
+{
+ struct nilfs_inode_info *ii;
+
+ ii = kmem_cache_alloc(nilfs_inode_cachep, GFP_NOFS);
+ if (!ii)
+ return NULL;
+ ii->i_bh = NULL;
+ ii->i_state = 0;
+ ii->vfs_inode.i_version = 1;
+ nilfs_btnode_cache_init(&ii->i_btnode_cache);
+ return &ii->vfs_inode;
+}
+
+void nilfs_destroy_inode(struct inode *inode)
+{
+ kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
+}
+
+static void init_once(void *obj)
+{
+ struct nilfs_inode_info *ii = obj;
+
+ INIT_LIST_HEAD(&ii->i_dirty);
+#ifdef CONFIG_NILFS_XATTR
+ init_rwsem(&ii->xattr_sem);
+#endif
+ nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
+ ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union;
+ inode_init_once(&ii->vfs_inode);
+}
+
+static int nilfs_init_inode_cache(void)
+{
+ nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
+ sizeof(struct nilfs_inode_info),
+ 0, SLAB_RECLAIM_ACCOUNT,
+ init_once);
+
+ return (nilfs_inode_cachep == NULL) ? -ENOMEM : 0;
+}
+
+static inline void nilfs_destroy_inode_cache(void)
+{
+ kmem_cache_destroy(nilfs_inode_cachep);
+}
+
+static void nilfs_clear_inode(struct inode *inode)
+{
+ struct nilfs_inode_info *ii = NILFS_I(inode);
+ struct nilfs_transaction_info ti;
+ struct nilfs_sb_info *sbi = NILFS_SB(inode->i_sb);
+
+#ifdef CONFIG_NILFS_POSIX_ACL
+ if (ii->i_acl && ii->i_acl != NILFS_ACL_NOT_CACHED) {
+ posix_acl_release(ii->i_acl);
+ ii->i_acl = NILFS_ACL_NOT_CACHED;
+ }
+ if (ii->i_default_acl && ii->i_default_acl != NILFS_ACL_NOT_CACHED) {
+ posix_acl_release(ii->i_default_acl);
+ ii->i_default_acl = NILFS_ACL_NOT_CACHED;
+ }
+#endif
+ /*
+ * Free resources allocated in nilfs_read_inode(), here.
+ */
+ nilfs_transaction_begin(inode->i_sb, &ti, 0);
+
+ spin_lock(&sbi->s_inode_lock);
+ if (!list_empty(&ii->i_dirty))
+ list_del_init(&ii->i_dirty);
+ brelse(ii->i_bh);
+ ii->i_bh = NULL;
+ spin_unlock(&sbi->s_inode_lock);
+
+ if (test_bit(NILFS_I_BMAP, &ii->i_state))
+ nilfs_bmap_clear(ii->i_bmap);
+
+ nilfs_btnode_cache_clear(&ii->i_btnode_cache);
+
+ nilfs_transaction_end(inode->i_sb, 0);
+}
+
+/**
+ * nilfs_update_last_segment - change pointer to the latest segment
+ * @sbi: nilfs_sb_info
+ * @update_cno: flag whether to update checkpoint number.
+ *
+ * nilfs_update_last_segment() changes information in the super block
+ * after a partial segment is written out successfully. The super
+ * block is marked dirty. It will be written out at the next VFS sync
+ * operations such as sync_supers() and generic_shutdown_super().
+ */
+void nilfs_update_last_segment(struct nilfs_sb_info *sbi, int update_cno)
+{
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ struct nilfs_super_block *sbp = nilfs->ns_sbp;
+
+ /* nilfs->sem must be locked by the caller. */
+ spin_lock(&nilfs->ns_last_segment_lock);
+ if (update_cno)
+ nilfs->ns_last_cno = nilfs->ns_cno++;
+ sbp->s_last_seq = cpu_to_le64(nilfs->ns_last_seq);
+ sbp->s_last_pseg = cpu_to_le64(nilfs->ns_last_pseg);
+ sbp->s_last_cno = cpu_to_le64(nilfs->ns_last_cno);
+ spin_unlock(&nilfs->ns_last_segment_lock);
+
+ sbi->s_super->s_dirt = 1; /* must be set if delaying the call of
+ nilfs_commit_super() */
+}
+
+static int nilfs_sync_super(struct nilfs_sb_info *sbi)
+{
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ int err;
+ int barrier_done = 0;
+
+ if (nilfs_test_opt(sbi, BARRIER)) {
+ set_buffer_ordered(nilfs->ns_sbh);
+ barrier_done = 1;
+ }
+ retry:
+ set_buffer_dirty(nilfs->ns_sbh);
+ err = sync_dirty_buffer(nilfs->ns_sbh);
+ if (err == -EOPNOTSUPP && barrier_done) {
+ nilfs_warning(sbi->s_super, __func__,
+ "barrier-based sync failed. "
+ "disabling barriers\n");
+ nilfs_clear_opt(sbi, BARRIER);
+ barrier_done = 0;
+ clear_buffer_ordered(nilfs->ns_sbh);
+ goto retry;
+ }
+ if (unlikely(err))
+ printk(KERN_ERR
+ "NILFS: unable to write superblock (err=%d)\n", err);
+ else {
+ nilfs_dispose_used_segments(nilfs);
+ clear_nilfs_discontinued(nilfs);
+ }
+
+ return err;
+}
+
+int nilfs_commit_super(struct nilfs_sb_info *sbi)
+{
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ struct nilfs_super_block *sbp = nilfs->ns_sbp;
+ sector_t nfreeblocks;
+ int err;
+
+ /* nilfs->sem must be locked by the caller. */
+ err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
+ if (unlikely(err)) {
+ printk(KERN_ERR "NILFS: failed to count free blocks\n");
+ return err;
+ }
+ sbp->s_free_blocks_count = cpu_to_le64(nfreeblocks);
+ sbp->s_wtime = cpu_to_le64(get_seconds());
+ sbp->s_sum = 0;
+ sbp->s_sum = crc32_le(nilfs->ns_crc_seed, (unsigned char *)sbp,
+ le16_to_cpu(sbp->s_bytes));
+
+ sbi->s_super->s_dirt = 0;
+ return nilfs_sync_super(sbi);
+}
+
+static void nilfs_put_super(struct super_block *sb)
+{
+ struct nilfs_sb_info *sbi = NILFS_SB(sb);
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+
+ nilfs_detach_segment_constructor(sbi);
+
+ if (!(sb->s_flags & MS_RDONLY)) {
+ down_write(&nilfs->ns_sem);
+ nilfs->ns_sbp->s_state = cpu_to_le16(nilfs->ns_mount_state);
+ nilfs_commit_super(sbi);
+ up_write(&nilfs->ns_sem);
+ }
+
+ nilfs_detach_checkpoint(sbi);
+ put_nilfs(sbi->s_nilfs);
+ sbi->s_super = NULL;
+ sb->s_fs_info = NULL;
+ kfree(sbi);
+}
+
+/**
+ * nilfs_write_super - write super block(s) of NILFS
+ * @sb: super_block
+ *
+ * nilfs_write_super() gets a fs-dependent lock, writes super block(s), and
+ * clears s_dirt. This function is called in the section protected by
+ * lock_super().
+ *
+ * The s_dirt flag is managed by each filesystem and we protect it by ns_sem
+ * of the struct the_nilfs. Lock order must be as follows:
+ *
+ * 1. lock_super()
+ * 2. down_write(&nilfs->ns_sem)
+ *
+ * Inside NILFS, locking ns_sem is enough to protect s_dirt and the buffer
+ * of the super block (nilfs->ns_sbp).
+ *
+ * In most cases, VFS functions call lock_super() before calling these
+ * methods. So we must be careful not to bring on deadlocks when using
+ * lock_super(); see generic_shutdown_super(), write_super(), and so on.
+ *
+ * Note that order of lock_kernel() and lock_super() depends on contexts
+ * of VFS. We should also note that lock_kernel() can be used in its
+ * protective section and only the outermost one has an effect.
+ */
+static void nilfs_write_super(struct super_block *sb)
+{
+ struct nilfs_sb_info *sbi = NILFS_SB(sb);
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+
+ down_write(&nilfs->ns_sem);
+ if (!(sb->s_flags & MS_RDONLY))
+ nilfs_commit_super(sbi);
+ sb->s_dirt = 0;
+ up_write(&nilfs->ns_sem);
+}
+
+static int nilfs_sync_fs(struct super_block *sb, int wait)
+{
+ int err = 0;
+
+ /* This function is called when super block should be written back */
+ if (wait)
+ err = nilfs_construct_segment(sb);
+ return err;
+}
+
+int nilfs_attach_checkpoint(struct nilfs_sb_info *sbi, __u64 cno)
+{
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ struct nilfs_checkpoint *raw_cp;
+ struct buffer_head *bh_cp;
+ int err;
+
+ down_write(&nilfs->ns_sem);
+ list_add(&sbi->s_list, &nilfs->ns_supers);
+ up_write(&nilfs->ns_sem);
+
+ sbi->s_ifile = nilfs_mdt_new(
+ nilfs, sbi->s_super, NILFS_IFILE_INO, NILFS_IFILE_GFP);
+ if (!sbi->s_ifile)
+ return -ENOMEM;
+
+ err = nilfs_palloc_init_blockgroup(sbi->s_ifile, nilfs->ns_inode_size);
+ if (unlikely(err))
+ goto failed;
+
+ err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
+ &bh_cp);
+ if (unlikely(err)) {
+ if (err == -ENOENT || err == -EINVAL) {
+ printk(KERN_ERR
+ "NILFS: Invalid checkpoint "
+ "(checkpoint number=%llu)\n",
+ (unsigned long long)cno);
+ err = -EINVAL;
+ }
+ goto failed;
+ }
+ err = nilfs_read_inode_common(sbi->s_ifile, &raw_cp->cp_ifile_inode);
+ if (unlikely(err))
+ goto failed_bh;
+ atomic_set(&sbi->s_inodes_count, le64_to_cpu(raw_cp->cp_inodes_count));
+ atomic_set(&sbi->s_blocks_count, le64_to_cpu(raw_cp->cp_blocks_count));
+
+ nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
+ return 0;
+
+ failed_bh:
+ nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
+ failed:
+ nilfs_mdt_destroy(sbi->s_ifile);
+ sbi->s_ifile = NULL;
+
+ down_write(&nilfs->ns_sem);
+ list_del_init(&sbi->s_list);
+ up_write(&nilfs->ns_sem);
+
+ return err;
+}
+
+void nilfs_detach_checkpoint(struct nilfs_sb_info *sbi)
+{
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+
+ nilfs_mdt_clear(sbi->s_ifile);
+ nilfs_mdt_destroy(sbi->s_ifile);
+ sbi->s_ifile = NULL;
+ down_write(&nilfs->ns_sem);
+ list_del_init(&sbi->s_list);
+ up_write(&nilfs->ns_sem);
+}
+
+static int nilfs_mark_recovery_complete(struct nilfs_sb_info *sbi)
+{
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ int err = 0;
+
+ down_write(&nilfs->ns_sem);
+ if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) {
+ nilfs->ns_mount_state |= NILFS_VALID_FS;
+ err = nilfs_commit_super(sbi);
+ if (likely(!err))
+ printk(KERN_INFO "NILFS: recovery complete.\n");
+ }
+ up_write(&nilfs->ns_sem);
+ return err;
+}
+
+static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ struct super_block *sb = dentry->d_sb;
+ struct nilfs_sb_info *sbi = NILFS_SB(sb);
+ unsigned long long blocks;
+ unsigned long overhead;
+ unsigned long nrsvblocks;
+ sector_t nfreeblocks;
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ int err;
+
+ /*
+ * Compute all of the segment blocks
+ *
+ * The blocks before first segment and after last segment
+ * are excluded.
+ */
+ blocks = nilfs->ns_blocks_per_segment * nilfs->ns_nsegments
+ - nilfs->ns_first_data_block;
+ nrsvblocks = nilfs->ns_nrsvsegs * nilfs->ns_blocks_per_segment;
+
+ /*
+ * Compute the overhead
+ *
+ * When distributing meta data blocks outside semgent structure,
+ * We must count them as the overhead.
+ */
+ overhead = 0;
+
+ err = nilfs_count_free_blocks(nilfs, &nfreeblocks);
+ if (unlikely(err))
+ return err;
+
+ buf->f_type = NILFS_SUPER_MAGIC;
+ buf->f_bsize = sb->s_blocksize;
+ buf->f_blocks = blocks - overhead;
+ buf->f_bfree = nfreeblocks;
+ buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
+ (buf->f_bfree - nrsvblocks) : 0;
+ buf->f_files = atomic_read(&sbi->s_inodes_count);
+ buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
+ buf->f_namelen = NILFS_NAME_LEN;
+ return 0;
+}
+
+static struct super_operations nilfs_sops = {
+ .alloc_inode = nilfs_alloc_inode,
+ .destroy_inode = nilfs_destroy_inode,
+ .dirty_inode = nilfs_dirty_inode,
+ /* .write_inode = nilfs_write_inode, */
+ /* .put_inode = nilfs_put_inode, */
+ /* .drop_inode = nilfs_drop_inode, */
+ .delete_inode = nilfs_delete_inode,
+ .put_super = nilfs_put_super,
+ .write_super = nilfs_write_super,
+ .sync_fs = nilfs_sync_fs,
+ /* .write_super_lockfs */
+ /* .unlockfs */
+ .statfs = nilfs_statfs,
+ .remount_fs = nilfs_remount,
+ .clear_inode = nilfs_clear_inode,
+ /* .umount_begin */
+ /* .show_options */
+};
+
+static struct inode *
+nilfs_nfs_get_inode(struct super_block *sb, u64 ino, u32 generation)
+{
+ struct inode *inode;
+
+ if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO &&
+ ino != NILFS_SKETCH_INO)
+ return ERR_PTR(-ESTALE);
+
+ inode = nilfs_iget(sb, ino);
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
+ if (generation && inode->i_generation != generation) {
+ iput(inode);
+ return ERR_PTR(-ESTALE);
+ }
+
+ return inode;
+}
+
+static struct dentry *
+nilfs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
+ int fh_type)
+{
+ return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+ nilfs_nfs_get_inode);
+}
+
+static struct dentry *
+nilfs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len,
+ int fh_type)
+{
+ return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+ nilfs_nfs_get_inode);
+}
+
+static struct export_operations nilfs_export_ops = {
+ .fh_to_dentry = nilfs_fh_to_dentry,
+ .fh_to_parent = nilfs_fh_to_parent,
+ .get_parent = nilfs_get_parent,
+};
+
+enum {
+ Opt_err_cont, Opt_err_panic, Opt_err_ro,
+ Opt_barrier, Opt_snapshot, Opt_order,
+ Opt_err,
+};
+
+static match_table_t tokens = {
+ {Opt_err_cont, "errors=continue"},
+ {Opt_err_panic, "errors=panic"},
+ {Opt_err_ro, "errors=remount-ro"},
+ {Opt_barrier, "barrier=%s"},
+ {Opt_snapshot, "cp=%u"},
+ {Opt_order, "order=%s"},
+ {Opt_err, NULL}
+};
+
+static int match_bool(substring_t *s, int *result)
+{
+ int len = s->to - s->from;
+
+ if (strncmp(s->from, "on", len) == 0)
+ *result = 1;
+ else if (strncmp(s->from, "off", len) == 0)
+ *result = 0;
+ else
+ return 1;
+ return 0;
+}
+
+static int parse_options(char *options, struct super_block *sb)
+{
+ struct nilfs_sb_info *sbi = NILFS_SB(sb);
+ char *p;
+ substring_t args[MAX_OPT_ARGS];
+ int option;
+
+ if (!options)
+ return 1;
+
+ while ((p = strsep(&options, ",")) != NULL) {
+ int token;
+ if (!*p)
+ continue;
+
+ token = match_token(p, tokens, args);
+ switch (token) {
+ case Opt_barrier:
+ if (match_bool(&args[0], &option))
+ return 0;
+ if (option)
+ nilfs_set_opt(sbi, BARRIER);
+ else
+ nilfs_clear_opt(sbi, BARRIER);
+ break;
+ case Opt_order:
+ if (strcmp(args[0].from, "relaxed") == 0)
+ /* Ordered data semantics */
+ nilfs_clear_opt(sbi, STRICT_ORDER);
+ else if (strcmp(args[0].from, "strict") == 0)
+ /* Strict in-order semantics */
+ nilfs_set_opt(sbi, STRICT_ORDER);
+ else
+ return 0;
+ break;
+ case Opt_err_panic:
+ nilfs_write_opt(sbi, ERROR_MODE, ERRORS_PANIC);
+ break;
+ case Opt_err_ro:
+ nilfs_write_opt(sbi, ERROR_MODE, ERRORS_RO);
+ break;
+ case Opt_err_cont:
+ nilfs_write_opt(sbi, ERROR_MODE, ERRORS_CONT);
+ break;
+ case Opt_snapshot:
+ if (match_int(&args[0], &option) || option <= 0)
+ return 0;
+ if (!(sb->s_flags & MS_RDONLY))
+ return 0;
+ sbi->s_snapshot_cno = option;
+ nilfs_set_opt(sbi, SNAPSHOT);
+ break;
+ default:
+ printk(KERN_ERR
+ "NILFS: Unrecognized mount option \"%s\"\n", p);
+ return 0;
+ }
+ }
+ return 1;
+}
+
+static inline void
+nilfs_set_default_options(struct nilfs_sb_info *sbi,
+ struct nilfs_super_block *sbp)
+{
+ sbi->s_mount_opt =
+ NILFS_MOUNT_ERRORS_CONT | NILFS_MOUNT_BARRIER;
+}
+
+static int nilfs_setup_super(struct nilfs_sb_info *sbi)
+{
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ struct nilfs_super_block *sbp = nilfs->ns_sbp;
+ int max_mnt_count = le16_to_cpu(sbp->s_max_mnt_count);
+ int mnt_count = le16_to_cpu(sbp->s_mnt_count);
+
+ /* nilfs->sem must be locked by the caller. */
+ if (!(nilfs->ns_mount_state & NILFS_VALID_FS)) {
+ printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n");
+ } else if (nilfs->ns_mount_state & NILFS_ERROR_FS) {
+ printk(KERN_WARNING
+ "NILFS warning: mounting fs with errors\n");
+#if 0
+ } else if (max_mnt_count >= 0 && mnt_count >= max_mnt_count) {
+ printk(KERN_WARNING
+ "NILFS warning: maximal mount count reached\n");
+#endif
+ }
+ if (!max_mnt_count)
+ sbp->s_max_mnt_count = cpu_to_le16(NILFS_DFL_MAX_MNT_COUNT);
+
+ sbp->s_mnt_count = cpu_to_le16(mnt_count + 1);
+ sbp->s_state = cpu_to_le16(le16_to_cpu(sbp->s_state) & ~NILFS_VALID_FS);
+ sbp->s_mtime = cpu_to_le64(get_seconds());
+ return nilfs_commit_super(sbi);
+}
+
+struct nilfs_super_block *
+nilfs_load_super_block(struct super_block *sb, struct buffer_head **pbh)
+{
+ int blocksize;
+ unsigned long offset, sb_index;
+
+ /*
+ * Adjusting block size
+ * Blocksize will be enlarged when it is smaller than hardware
+ * sector size.
+ * Disk format of superblock does not change.
+ */
+ blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
+ if (!blocksize) {
+ printk(KERN_ERR
+ "NILFS: unable to set blocksize of superblock\n");
+ return NULL;
+ }
+ sb_index = NILFS_SB_OFFSET_BYTES / blocksize;
+ offset = NILFS_SB_OFFSET_BYTES % blocksize;
+
+ *pbh = sb_bread(sb, sb_index);
+ if (!*pbh) {
+ printk(KERN_ERR "NILFS: unable to read superblock\n");
+ return NULL;
+ }
+ return (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
+}
+
+struct nilfs_super_block *
+nilfs_reload_super_block(struct super_block *sb, struct buffer_head **pbh,
+ int blocksize)
+{
+ struct nilfs_super_block *sbp;
+ unsigned long offset, sb_index;
+ int hw_blocksize = bdev_hardsect_size(sb->s_bdev);
+
+ if (blocksize < hw_blocksize) {
+ printk(KERN_ERR
+ "NILFS: blocksize %d too small for device "
+ "(sector-size = %d).\n",
+ blocksize, hw_blocksize);
+ goto failed_sbh;
+ }
+ brelse(*pbh);
+ sb_set_blocksize(sb, blocksize);
+
+ sb_index = NILFS_SB_OFFSET_BYTES / blocksize;
+ offset = NILFS_SB_OFFSET_BYTES % blocksize;
+
+ *pbh = sb_bread(sb, sb_index);
+ if (!*pbh) {
+ printk(KERN_ERR
+ "NILFS: cannot read superblock on 2nd try.\n");
+ goto failed;
+ }
+
+ sbp = (struct nilfs_super_block *)((char *)(*pbh)->b_data + offset);
+ if (sbp->s_magic != cpu_to_le16(NILFS_SUPER_MAGIC)) {
+ printk(KERN_ERR
+ "NILFS: !? Magic mismatch on 2nd try.\n");
+ goto failed_sbh;
+ }
+ return sbp;
+
+ failed_sbh:
+ brelse(*pbh);
+
+ failed:
+ return NULL;
+}
+
+int nilfs_store_magic_and_option(struct super_block *sb,
+ struct nilfs_super_block *sbp,
+ char *data)
+{
+ struct nilfs_sb_info *sbi = NILFS_SB(sb);
+
+ /* trying to fill super (1st stage) */
+ sb->s_magic = le16_to_cpu(sbp->s_magic);
+
+ /* FS independent flags */
+#ifdef NILFS_ATIME_DISABLE
+ sb->s_flags |= MS_NOATIME;
+#endif
+
+ if (sb->s_magic != NILFS_SUPER_MAGIC) {
+ printk("NILFS: Can't find nilfs on dev %s.\n", sb->s_id);
+ return -EINVAL;
+ }
+
+ nilfs_set_default_options(sbi, sbp);
+
+ sbi->s_resuid = le16_to_cpu(sbp->s_def_resuid);
+ sbi->s_resgid = le16_to_cpu(sbp->s_def_resgid);
+ sbi->s_interval = le32_to_cpu(sbp->s_c_interval);
+ sbi->s_watermark = le32_to_cpu(sbp->s_c_block_max);
+
+ if (!parse_options(data, sb))
+ return -EINVAL;
+
+ return 0;
+}
+
+/**
+ * nilfs_fill_super() - initialize a super block instance
+ * @sb: super_block
+ * @data: mount options
+ * @silent: silent mode flag
+ * @nilfs: the_nilfs struct
+ *
+ * This function is called exclusively by bd_mount_mutex.
+ * So, the recovery process is protected from other simultaneous mounts.
+ */
+static int
+nilfs_fill_super(struct super_block *sb, void *data, int silent,
+ struct the_nilfs *nilfs)
+{
+ struct nilfs_sb_info *sbi;
+ struct inode *root;
+ __u64 cno;
+ int err;
+
+ sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+ if (!sbi)
+ return -ENOMEM;
+
+ sb->s_fs_info = sbi;
+
+ get_nilfs(nilfs);
+ sbi->s_nilfs = nilfs;
+ sbi->s_super = sb;
+
+ err = init_nilfs(nilfs, sbi, (char *)data);
+ if (err)
+ goto failed_sbi;
+
+ spin_lock_init(&sbi->s_inode_lock);
+ INIT_LIST_HEAD(&sbi->s_dirty_files);
+ INIT_LIST_HEAD(&sbi->s_list);
+
+ /*
+ * Following initialization is overlapped because
+ * nilfs_sb_info structure has been cleared at the beginning.
+ * But we reserve them to keep our interest and make ready
+ * for the future change.
+ */
+ get_random_bytes(&sbi->s_next_generation,
+ sizeof(sbi->s_next_generation));
+ spin_lock_init(&sbi->s_next_gen_lock);
+
+ sb->s_op = &nilfs_sops;
+ sb->s_export_op = &nilfs_export_ops;
+ sb->s_root = NULL;
+
+ if (!nilfs_loaded(nilfs)) {
+ err = load_nilfs(nilfs, sbi);
+ if (err)
+ goto failed_sbi;
+ }
+ cno = nilfs_last_cno(nilfs);
+
+ if (sb->s_flags & MS_RDONLY) {
+ if (nilfs_test_opt(sbi, SNAPSHOT)) {
+ if (!nilfs_cpfile_is_snapshot(nilfs->ns_cpfile,
+ sbi->s_snapshot_cno)) {
+ printk(KERN_ERR
+ "NILFS: The specified checkpoint is "
+ "not a snapshot "
+ "(checkpoint number=%llu).\n",
+ (unsigned long long)sbi->s_snapshot_cno);
+ err = -EINVAL;
+ goto failed_sbi;
+ }
+ cno = sbi->s_snapshot_cno;
+ } else
+ /* Read-only mount */
+ sbi->s_snapshot_cno = cno;
+ }
+
+ err = nilfs_attach_checkpoint(sbi, cno);
+ if (err) {
+ printk(KERN_ERR "NILFS: error loading a checkpoint"
+ " (checkpoint number=%llu).\n", (unsigned long long)cno);
+ goto failed_sbi;
+ }
+
+ if (!(sb->s_flags & MS_RDONLY)) {
+ err = nilfs_attach_segment_constructor(sbi, NULL);
+ if (err)
+ goto failed_checkpoint;
+ }
+
+ root = nilfs_iget(sb, NILFS_ROOT_INO);
+ if (IS_ERR(root)) {
+ printk(KERN_ERR "NILFS: get root inode failed\n");
+ err = PTR_ERR(root);
+ goto failed_segctor;
+ }
+ if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
+ iput(root);
+ printk(KERN_ERR "NILFS: corrupt root inode.\n");
+ err = -EINVAL;
+ goto failed_segctor;
+ }
+ sb->s_root = d_alloc_root(root);
+ if (!sb->s_root) {
+ iput(root);
+ printk(KERN_ERR "NILFS: get root dentry failed\n");
+ err = -ENOMEM;
+ goto failed_segctor;
+ }
+
+ if (!(sb->s_flags & MS_RDONLY)) {
+ down_write(&nilfs->ns_sem);
+ nilfs_setup_super(sbi);
+ up_write(&nilfs->ns_sem);
+ }
+
+ err = nilfs_mark_recovery_complete(sbi);
+ if (unlikely(err)) {
+ printk(KERN_ERR "NILFS: recovery failed.\n");
+ goto failed_root;
+ }
+
+ return 0;
+
+ failed_root:
+ dput(sb->s_root);
+ sb->s_root = NULL;
+
+ failed_segctor:
+ nilfs_detach_segment_constructor(sbi);
+
+ failed_checkpoint:
+ nilfs_detach_checkpoint(sbi);
+
+ failed_sbi:
+ put_nilfs(nilfs);
+ sb->s_fs_info = NULL;
+ kfree(sbi);
+ return err;
+}
+
+static int nilfs_remount(struct super_block *sb, int *flags, char *data)
+{
+ struct nilfs_sb_info *sbi = NILFS_SB(sb);
+ struct nilfs_super_block *sbp;
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ unsigned long old_sb_flags;
+ struct nilfs_mount_options old_opts;
+ int err;
+
+ old_sb_flags = sb->s_flags;
+ old_opts.mount_opt = sbi->s_mount_opt;
+ old_opts.snapshot_cno = sbi->s_snapshot_cno;
+
+ if (!parse_options(data, sb)) {
+ err = -EINVAL;
+ goto restore_opts;
+ }
+ sb->s_flags = (sb->s_flags & ~MS_POSIXACL);
+
+ if ((*flags & MS_RDONLY) &&
+ sbi->s_snapshot_cno != old_opts.snapshot_cno) {
+ printk(KERN_WARNING "NILFS (device %s): couldn't "
+ "remount to a different snapshot. \n",
+ sb->s_id);
+ err = -EINVAL;
+ goto restore_opts;
+ }
+
+ if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
+ goto out;
+ if (*flags & MS_RDONLY) {
+ /* Shutting down the segment constructor */
+ nilfs_detach_segment_constructor(sbi);
+ sb->s_flags |= MS_RDONLY;
+
+ sbi->s_snapshot_cno = nilfs_last_cno(nilfs);
+ /* nilfs_set_opt(sbi, SNAPSHOT); */
+
+ /*
+ * Remounting a valid RW partition RDONLY, so set
+ * the RDONLY flag and then mark the partition as valid again.
+ */
+ down_write(&nilfs->ns_sem);
+ sbp = nilfs->ns_sbp;
+ if (!(sbp->s_state & le16_to_cpu(NILFS_VALID_FS)) &&
+ (nilfs->ns_mount_state & NILFS_VALID_FS))
+ sbp->s_state = cpu_to_le16(nilfs->ns_mount_state);
+ sbp->s_mtime = cpu_to_le64(get_seconds());
+ nilfs_commit_super(sbi);
+ up_write(&nilfs->ns_sem);
+ } else {
+ /*
+ * Mounting a RDONLY partition read-write, so reread and
+ * store the current valid flag. (It may have been changed
+ * by fsck since we originally mounted the partition.)
+ */
+ down(&sb->s_bdev->bd_mount_sem);
+ /* Check existing RW-mount */
+ if (test_exclusive_mount(sb->s_type, sb->s_bdev, 0)) {
+ printk(KERN_WARNING "NILFS (device %s): couldn't "
+ "remount because a RW-mount exists.\n",
+ sb->s_id);
+ err = -EBUSY;
+ goto rw_remount_failed;
+ }
+ if (sbi->s_snapshot_cno != nilfs_last_cno(nilfs)) {
+ printk(KERN_WARNING "NILFS (device %s): couldn't "
+ "remount because the current RO-mount is not "
+ "the latest one.\n",
+ sb->s_id);
+ err = -EINVAL;
+ goto rw_remount_failed;
+ }
+ sb->s_flags &= ~MS_RDONLY;
+ nilfs_clear_opt(sbi, SNAPSHOT);
+ sbi->s_snapshot_cno = 0;
+
+ err = nilfs_attach_segment_constructor(sbi, NULL);
+ if (err)
+ goto rw_remount_failed;
+
+ down_write(&nilfs->ns_sem);
+ nilfs_setup_super(sbi);
+ up_write(&nilfs->ns_sem);
+
+ up(&sb->s_bdev->bd_mount_sem);
+ }
+ out:
+ return 0;
+
+ rw_remount_failed:
+ up(&sb->s_bdev->bd_mount_sem);
+ restore_opts:
+ sb->s_flags = old_sb_flags;
+ sbi->s_mount_opt = old_opts.mount_opt;
+ sbi->s_snapshot_cno = old_opts.snapshot_cno;
+ return err;
+}
+
+struct nilfs_super_data {
+ struct block_device *bdev;
+ __u64 cno;
+ int flags;
+};
+
+/**
+ * nilfs_identify - pre-read mount options needed to identify mount instance
+ * @data: mount options
+ * @sd: nilfs_super_data
+ */
+static int nilfs_identify(char *data, struct nilfs_super_data *sd)
+{
+ char *p, *options = data;
+ substring_t args[MAX_OPT_ARGS];
+ int option, token;
+ int ret = 0;
+
+ do {
+ p = strsep(&options, ",");
+ if (p != NULL && *p) {
+ token = match_token(p, tokens, args);
+ if (token == Opt_snapshot) {
+ if (!(sd->flags & MS_RDONLY))
+ ret++;
+ else {
+ ret = match_int(&args[0], &option);
+ if (!ret) {
+ if (option > 0)
+ sd->cno = option;
+ else
+ ret++;
+ }
+ }
+ }
+ if (ret)
+ printk(KERN_ERR
+ "NILFS: invalid mount option: %s\n", p);
+ }
+ if (!options)
+ break;
+ BUG_ON(options == data);
+ *(options - 1) = ',';
+ } while (!ret);
+ return ret;
+}
+
+static int nilfs_set_bdev_super(struct super_block *s, void *data)
+{
+ struct nilfs_super_data *sd = data;
+
+ s->s_bdev = sd->bdev;
+ s->s_dev = s->s_bdev->bd_dev;
+ return 0;
+}
+
+static int nilfs_test_bdev_super(struct super_block *s, void *data)
+{
+ struct nilfs_super_data *sd = data;
+
+ return s->s_bdev == sd->bdev;
+}
+
+static int nilfs_test_bdev_super2(struct super_block *s, void *data)
+{
+ struct nilfs_super_data *sd = data;
+ int ret;
+
+ if (s->s_bdev != sd->bdev)
+ return 0;
+
+ if (!((s->s_flags | sd->flags) & MS_RDONLY))
+ return 1; /* Reuse an old R/W-mode super_block */
+
+ if (s->s_flags & sd->flags & MS_RDONLY) {
+ if (down_read_trylock(&s->s_umount)) {
+ ret = s->s_root &&
+ (sd->cno == NILFS_SB(s)->s_snapshot_cno);
+ up_read(&s->s_umount);
+ /*
+ * This path is locked with sb_lock by sget().
+ * So, drop_super() causes deadlock.
+ */
+ return ret;
+ }
+ }
+ return 0;
+}
+
+static int
+nilfs_get_sb(struct file_system_type *fs_type, int flags,
+ const char *dev_name, void *data, struct vfsmount *mnt)
+{
+ struct nilfs_super_data sd;
+ struct super_block *s, *s2;
+ struct the_nilfs *nilfs = NULL;
+ int err, need_to_close = 1;
+
+ sd.bdev = open_bdev_exclusive(dev_name, flags, fs_type);
+ if (IS_ERR(sd.bdev))
+ return PTR_ERR(sd.bdev);
+
+ /*
+ * To get mount instance using sget() vfs-routine, NILFS needs
+ * much more information than normal filesystems to identify mount
+ * instance. For snapshot mounts, not only a mount type (ro-mount
+ * or rw-mount) but also a checkpoint number is required.
+ * The results are passed in sget() using nilfs_super_data.
+ */
+ sd.cno = 0;
+ sd.flags = flags;
+ if (nilfs_identify((char *)data, &sd)) {
+ err = -EINVAL;
+ goto failed;
+ }
+
+ /*
+ * once the super is inserted into the list by sget, s_umount
+ * will protect the lockfs code from trying to start a snapshot
+ * while we are mounting
+ */
+ down(&sd.bdev->bd_mount_sem);
+ if (!sd.cno &&
+ (err = test_exclusive_mount(fs_type, sd.bdev, flags ^ MS_RDONLY))) {
+ err = (err < 0) ? : -EBUSY;
+ goto failed_unlock;
+ }
+
+ /*
+ * Phase-1: search any existent instance and get the_nilfs
+ */
+ s = sget(fs_type, nilfs_test_bdev_super, nilfs_set_bdev_super, &sd);
+ if (IS_ERR(s))
+ goto error_s;
+
+ if (!s->s_root) {
+ err = -ENOMEM;
+ nilfs = alloc_nilfs(sd.bdev);
+ if (!nilfs)
+ goto cancel_new;
+ } else {
+ struct nilfs_sb_info *sbi = NILFS_SB(s);
+
+ BUG_ON(!sbi || !sbi->s_nilfs);
+ /*
+ * s_umount protects super_block from unmount process;
+ * It covers pointers of nilfs_sb_info and the_nilfs.
+ */
+ nilfs = sbi->s_nilfs;
+ get_nilfs(nilfs);
+ up_write(&s->s_umount);
+
+ /*
+ * Phase-2: search specified snapshot or R/W mode super_block
+ */
+ if (!sd.cno)
+ /* trying to get the latest checkpoint. */
+ sd.cno = nilfs_last_cno(nilfs);
+
+ s2 = sget(fs_type, nilfs_test_bdev_super2,
+ nilfs_set_bdev_super, &sd);
+ deactivate_super(s);
+ /*
+ * Although deactivate_super() invokes close_bdev_exclusive() at
+ * kill_block_super(). Here, s is an existent mount; we need
+ * one more close_bdev_exclusive() call.
+ */
+ s = s2;
+ if (IS_ERR(s))
+ goto error_s;
+ }
+
+ if (!s->s_root) {
+ char b[BDEVNAME_SIZE];
+
+ s->s_flags = flags;
+ strlcpy(s->s_id, bdevname(sd.bdev, b), sizeof(s->s_id));
+ sb_set_blocksize(s, block_size(sd.bdev));
+
+ err = nilfs_fill_super(s, data, flags & MS_VERBOSE, nilfs);
+ if (err)
+ goto cancel_new;
+
+ s->s_flags |= MS_ACTIVE;
+ need_to_close = 0;
+ } else if (!(s->s_flags & MS_RDONLY)) {
+ err = -EBUSY;
+ }
+
+ up(&sd.bdev->bd_mount_sem);
+ put_nilfs(nilfs);
+ if (need_to_close)
+ close_bdev_exclusive(sd.bdev, flags);
+ simple_set_mnt(mnt, s);
+ return 0;
+
+ error_s:
+ up(&sd.bdev->bd_mount_sem);
+ if (nilfs)
+ put_nilfs(nilfs);
+ close_bdev_exclusive(sd.bdev, flags);
+ return PTR_ERR(s);
+
+ failed_unlock:
+ up(&sd.bdev->bd_mount_sem);
+ failed:
+ close_bdev_exclusive(sd.bdev, flags);
+
+ return err;
+
+ cancel_new:
+ /* Abandoning the newly allocated superblock */
+ up(&sd.bdev->bd_mount_sem);
+ if (nilfs)
+ put_nilfs(nilfs);
+ up_write(&s->s_umount);
+ deactivate_super(s);
+ /*
+ * deactivate_super() invokes close_bdev_exclusive().
+ * We must finish all post-cleaning before this call;
+ * put_nilfs() and unlocking bd_mount_sem need the block device.
+ */
+ return err;
+}
+
+static int nilfs_test_bdev_super3(struct super_block *s, void *data)
+{
+ struct nilfs_super_data *sd = data;
+ int ret;
+
+ if (s->s_bdev != sd->bdev)
+ return 0;
+ if (down_read_trylock(&s->s_umount)) {
+ ret = (s->s_flags & MS_RDONLY) && s->s_root &&
+ nilfs_test_opt(NILFS_SB(s), SNAPSHOT);
+ up_read(&s->s_umount);
+ if (ret)
+ return 0; /* ignore snapshot mounts */
+ }
+ return !((sd->flags ^ s->s_flags) & MS_RDONLY);
+}
+
+static int __false_bdev_super(struct super_block *s, void *data)
+{
+#if 0 /* XXX: workaround for lock debug. This is not good idea */
+ up_write(&s->s_umount);
+#endif
+ return -EFAULT;
+}
+
+/**
+ * test_exclusive_mount - check whether an exclusive RW/RO mount exists or not.
+ * fs_type: filesystem type
+ * bdev: block device
+ * flag: 0 (check rw-mount) or MS_RDONLY (check ro-mount)
+ * res: pointer to an integer to store result
+ *
+ * This function must be called within a section protected by bd_mount_mutex.
+ */
+static int test_exclusive_mount(struct file_system_type *fs_type,
+ struct block_device *bdev, int flags)
+{
+ struct super_block *s;
+ struct nilfs_super_data sd = { .flags = flags, .bdev = bdev };
+
+ s = sget(fs_type, nilfs_test_bdev_super3, __false_bdev_super, &sd);
+ if (IS_ERR(s)) {
+ if (PTR_ERR(s) != -EFAULT)
+ return PTR_ERR(s);
+ return 0; /* Not found */
+ }
+ up_write(&s->s_umount);
+ deactivate_super(s);
+ return 1; /* Found */
+}
+
+struct file_system_type nilfs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "nilfs2",
+ .get_sb = nilfs_get_sb,
+ .kill_sb = kill_block_super,
+ .fs_flags = FS_REQUIRES_DEV,
+};
+
+static int __init init_nilfs_fs(void)
+{
+ int err;
+
+ err = nilfs_init_inode_cache();
+ if (err)
+ goto failed;
+
+ err = nilfs_init_transaction_cache();
+ if (err)
+ goto failed_inode_cache;
+
+ err = nilfs_init_segbuf_cache();
+ if (err)
+ goto failed_transaction_cache;
+
+ err = nilfs_btree_path_cache_init();
+ if (err)
+ goto failed_segbuf_cache;
+
+ err = register_filesystem(&nilfs_fs_type);
+ if (err)
+ goto failed_btree_path_cache;
+
+ return 0;
+
+ failed_btree_path_cache:
+ nilfs_btree_path_cache_destroy();
+
+ failed_segbuf_cache:
+ nilfs_destroy_segbuf_cache();
+
+ failed_transaction_cache:
+ nilfs_destroy_transaction_cache();
+
+ failed_inode_cache:
+ nilfs_destroy_inode_cache();
+
+ failed:
+ return err;
+}
+
+static void __exit exit_nilfs_fs(void)
+{
+ nilfs_destroy_segbuf_cache();
+ nilfs_destroy_transaction_cache();
+ nilfs_destroy_inode_cache();
+ nilfs_btree_path_cache_destroy();
+ unregister_filesystem(&nilfs_fs_type);
+}
+
+module_init(init_nilfs_fs)
+module_exit(exit_nilfs_fs)
projects / openwrt / staging / blogic.git / commitdiff