From: Eric Van Hensbergen Date: Fri, 9 Sep 2005 20:04:18 +0000 (-0700) Subject: [PATCH] v9fs: VFS file, dentry, and directory operations X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=e69e7fe5b0c86b7271045444a3a681136234c659;p=openwrt%2Fstaging%2Fblogic.git [PATCH] v9fs: VFS file, dentry, and directory operations This part of the patch contains the VFS file, dentry & directory interfaces. Signed-off-by: Eric Van Hensbergen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/fs/9p/vfs_dentry.c b/fs/9p/vfs_dentry.c new file mode 100644 index 000000000000..306c96741f81 --- /dev/null +++ b/fs/9p/vfs_dentry.c @@ -0,0 +1,126 @@ +/* + * linux/fs/9p/vfs_dentry.c + * + * This file contians vfs dentry ops for the 9P2000 protocol. + * + * Copyright (C) 2004 by Eric Van Hensbergen + * Copyright (C) 2002 by Ron Minnich + * + * 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: + * Free Software Foundation + * 51 Franklin Street, Fifth Floor + * Boston, MA 02111-1301 USA + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "debug.h" +#include "v9fs.h" +#include "9p.h" +#include "v9fs_vfs.h" +#include "conv.h" +#include "fid.h" + +/** + * v9fs_dentry_validate - VFS dcache hook to validate cache + * @dentry: dentry that is being validated + * @nd: path data + * + * dcache really shouldn't be used for 9P2000 as at all due to + * potential attached semantics to directory traversal (walk). + * + * FUTURE: look into how to use dcache to allow multi-stage + * walks in Plan 9 & potential for better dcache operation which + * would remain valid for Plan 9 semantics. Older versions + * had validation via stat for those interested. However, since + * stat has the same approximate overhead as walk there really + * is no difference. The only improvement would be from a + * time-decay cache like NFS has and that undermines the + * synchronous nature of 9P2000. + * + */ + +static int v9fs_dentry_validate(struct dentry *dentry, struct nameidata *nd) +{ + struct dentry *dc = current->fs->pwd; + + dprintk(DEBUG_VFS, "dentry: %s (%p)\n", dentry->d_iname, dentry); + if (v9fs_fid_lookup(dentry, FID_OP)) { + dprintk(DEBUG_VFS, "VALID\n"); + return 1; + } + + while (dc != NULL) { + if (dc == dentry) { + dprintk(DEBUG_VFS, "VALID\n"); + return 1; + } + if (dc == dc->d_parent) + break; + + dc = dc->d_parent; + } + + dprintk(DEBUG_VFS, "INVALID\n"); + return 0; +} + +/** + * v9fs_dentry_release - called when dentry is going to be freed + * @dentry: dentry that is being release + * + */ + +void v9fs_dentry_release(struct dentry *dentry) +{ + dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry); + + if (dentry->d_fsdata != NULL) { + struct list_head *fid_list = dentry->d_fsdata; + struct v9fs_fid *temp = NULL; + struct v9fs_fid *current_fid = NULL; + struct v9fs_fcall *fcall = NULL; + + list_for_each_entry_safe(current_fid, temp, fid_list, list) { + if (v9fs_t_clunk + (current_fid->v9ses, current_fid->fid, &fcall)) + dprintk(DEBUG_ERROR, "clunk failed: %s\n", + FCALL_ERROR(fcall)); + + v9fs_put_idpool(current_fid->fid, + ¤t_fid->v9ses->fidpool); + + kfree(fcall); + v9fs_fid_destroy(current_fid); + } + + kfree(dentry->d_fsdata); /* free the list_head */ + } +} + +struct dentry_operations v9fs_dentry_operations = { + .d_revalidate = v9fs_dentry_validate, + .d_release = v9fs_dentry_release, +}; diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c new file mode 100644 index 000000000000..c478a7384186 --- /dev/null +++ b/fs/9p/vfs_dir.c @@ -0,0 +1,226 @@ +/* + * linux/fs/9p/vfs_dir.c + * + * This file contains vfs directory ops for the 9P2000 protocol. + * + * Copyright (C) 2004 by Eric Van Hensbergen + * Copyright (C) 2002 by Ron Minnich + * + * 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: + * Free Software Foundation + * 51 Franklin Street, Fifth Floor + * Boston, MA 02111-1301 USA + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "debug.h" +#include "v9fs.h" +#include "9p.h" +#include "v9fs_vfs.h" +#include "conv.h" +#include "fid.h" + +/** + * dt_type - return file type + * @mistat: mistat structure + * + */ + +static inline int dt_type(struct v9fs_stat *mistat) +{ + unsigned long perm = mistat->mode; + int rettype = DT_REG; + + if (perm & V9FS_DMDIR) + rettype = DT_DIR; + if (perm & V9FS_DMSYMLINK) + rettype = DT_LNK; + + return rettype; +} + +/** + * v9fs_dir_readdir - read a directory + * @filep: opened file structure + * @dirent: directory structure ??? + * @filldir: function to populate directory structure ??? + * + */ + +static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir) +{ + struct v9fs_fcall *fcall = NULL; + struct inode *inode = filp->f_dentry->d_inode; + struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); + struct v9fs_fid *file = filp->private_data; + unsigned int i, n; + int fid = -1; + int ret = 0; + struct v9fs_stat *mi = NULL; + int over = 0; + + dprintk(DEBUG_VFS, "name %s\n", filp->f_dentry->d_name.name); + + fid = file->fid; + + mi = kmalloc(v9ses->maxdata, GFP_KERNEL); + if (!mi) + return -ENOMEM; + + if (file->rdir_fcall && (filp->f_pos != file->rdir_pos)) { + kfree(file->rdir_fcall); + file->rdir_fcall = NULL; + } + + if (file->rdir_fcall) { + n = file->rdir_fcall->params.rread.count; + i = file->rdir_fpos; + while (i < n) { + int s = v9fs_deserialize_stat(v9ses, + file->rdir_fcall->params.rread.data + i, + n - i, mi, v9ses->maxdata); + + if (s == 0) { + dprintk(DEBUG_ERROR, + "error while deserializing mistat\n"); + ret = -EIO; + goto FreeStructs; + } + + over = filldir(dirent, mi->name, strlen(mi->name), + filp->f_pos, v9fs_qid2ino(&mi->qid), + dt_type(mi)); + + if (over) { + file->rdir_fpos = i; + file->rdir_pos = filp->f_pos; + break; + } + + i += s; + filp->f_pos += s; + } + + if (!over) { + kfree(file->rdir_fcall); + file->rdir_fcall = NULL; + } + } + + while (!over) { + ret = v9fs_t_read(v9ses, fid, filp->f_pos, + v9ses->maxdata-V9FS_IOHDRSZ, &fcall); + if (ret < 0) { + dprintk(DEBUG_ERROR, "error while reading: %d: %p\n", + ret, fcall); + goto FreeStructs; + } else if (ret == 0) + break; + + n = ret; + i = 0; + while (i < n) { + int s = v9fs_deserialize_stat(v9ses, + fcall->params.rread.data + i, n - i, mi, + v9ses->maxdata); + + if (s == 0) { + dprintk(DEBUG_ERROR, + "error while deserializing mistat\n"); + return -EIO; + } + + over = filldir(dirent, mi->name, strlen(mi->name), + filp->f_pos, v9fs_qid2ino(&mi->qid), + dt_type(mi)); + + if (over) { + file->rdir_fcall = fcall; + file->rdir_fpos = i; + file->rdir_pos = filp->f_pos; + fcall = NULL; + break; + } + + i += s; + filp->f_pos += s; + } + + kfree(fcall); + } + + FreeStructs: + kfree(fcall); + kfree(mi); + return ret; +} + +/** + * v9fs_dir_release - close a directory + * @inode: inode of the directory + * @filp: file pointer to a directory + * + */ + +int v9fs_dir_release(struct inode *inode, struct file *filp) +{ + struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); + struct v9fs_fid *fid = filp->private_data; + int fidnum = -1; + + dprintk(DEBUG_VFS, "inode: %p filp: %p fid: %d\n", inode, filp, + fid->fid); + fidnum = fid->fid; + + filemap_fdatawrite(inode->i_mapping); + filemap_fdatawait(inode->i_mapping); + + if (fidnum >= 0) { + fid->fidopen--; + dprintk(DEBUG_VFS, "fidopen: %d v9f->fid: %d\n", fid->fidopen, + fid->fid); + + if (fid->fidopen == 0) { + if (v9fs_t_clunk(v9ses, fidnum, NULL)) + dprintk(DEBUG_ERROR, "clunk failed\n"); + + v9fs_put_idpool(fid->fid, &v9ses->fidpool); + } + + kfree(fid->rdir_fcall); + + filp->private_data = NULL; + v9fs_fid_destroy(fid); + } + + d_drop(filp->f_dentry); + return 0; +} + +struct file_operations v9fs_dir_operations = { + .read = generic_read_dir, + .readdir = v9fs_dir_readdir, + .open = v9fs_file_open, + .release = v9fs_dir_release, +}; diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c new file mode 100644 index 000000000000..1f8ae7d580ab --- /dev/null +++ b/fs/9p/vfs_file.c @@ -0,0 +1,401 @@ +/* + * linux/fs/9p/vfs_file.c + * + * This file contians vfs file ops for 9P2000. + * + * Copyright (C) 2004 by Eric Van Hensbergen + * Copyright (C) 2002 by Ron Minnich + * + * 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: + * Free Software Foundation + * 51 Franklin Street, Fifth Floor + * Boston, MA 02111-1301 USA + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "debug.h" +#include "v9fs.h" +#include "9p.h" +#include "v9fs_vfs.h" +#include "fid.h" + +/** + * v9fs_file_open - open a file (or directory) + * @inode: inode to be opened + * @file: file being opened + * + */ + +int v9fs_file_open(struct inode *inode, struct file *file) +{ + struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); + struct v9fs_fid *v9fid = v9fs_fid_lookup(file->f_dentry, FID_WALK); + struct v9fs_fid *v9newfid = NULL; + struct v9fs_fcall *fcall = NULL; + int open_mode = 0; + unsigned int iounit = 0; + int newfid = -1; + long result = -1; + + dprintk(DEBUG_VFS, "inode: %p file: %p v9fid= %p\n", inode, file, + v9fid); + + if (!v9fid) { + struct dentry *dentry = file->f_dentry; + dprintk(DEBUG_ERROR, "Couldn't resolve fid from dentry\n"); + + /* XXX - some duplication from lookup, generalize later */ + /* basically vfs_lookup is too heavy weight */ + v9fid = v9fs_fid_lookup(file->f_dentry, FID_OP); + if (!v9fid) + return -EBADF; + + v9fid = v9fs_fid_lookup(dentry->d_parent, FID_WALK); + if (!v9fid) + return -EBADF; + + newfid = v9fs_get_idpool(&v9ses->fidpool); + if (newfid < 0) { + eprintk(KERN_WARNING, "newfid fails!\n"); + return -ENOSPC; + } + + result = + v9fs_t_walk(v9ses, v9fid->fid, newfid, + (char *)file->f_dentry->d_name.name, NULL); + if (result < 0) { + v9fs_put_idpool(newfid, &v9ses->fidpool); + dprintk(DEBUG_ERROR, "rewalk didn't work\n"); + return -EBADF; + } + + v9fid = v9fs_fid_create(dentry); + if (v9fid == NULL) { + dprintk(DEBUG_ERROR, "couldn't insert\n"); + return -ENOMEM; + } + v9fid->fid = newfid; + } + + if (v9fid->fidcreate) { + /* create case */ + newfid = v9fid->fid; + iounit = v9fid->iounit; + v9fid->fidcreate = 0; + } else { + if (!S_ISDIR(inode->i_mode)) + newfid = v9fid->fid; + else { + newfid = v9fs_get_idpool(&v9ses->fidpool); + if (newfid < 0) { + eprintk(KERN_WARNING, "allocation failed\n"); + return -ENOSPC; + } + /* This would be a somewhat critical clone */ + result = + v9fs_t_walk(v9ses, v9fid->fid, newfid, NULL, + &fcall); + if (result < 0) { + dprintk(DEBUG_ERROR, "clone error: %s\n", + FCALL_ERROR(fcall)); + kfree(fcall); + return result; + } + + v9newfid = v9fs_fid_create(file->f_dentry); + v9newfid->fid = newfid; + v9newfid->qid = v9fid->qid; + v9newfid->iounit = v9fid->iounit; + v9newfid->fidopen = 0; + v9newfid->fidclunked = 0; + v9newfid->v9ses = v9ses; + v9fid = v9newfid; + kfree(fcall); + } + + /* TODO: do special things for O_EXCL, O_NOFOLLOW, O_SYNC */ + /* translate open mode appropriately */ + open_mode = file->f_flags & 0x3; + + if (file->f_flags & O_EXCL) + open_mode |= V9FS_OEXCL; + + if (v9ses->extended) { + if (file->f_flags & O_TRUNC) + open_mode |= V9FS_OTRUNC; + + if (file->f_flags & O_APPEND) + open_mode |= V9FS_OAPPEND; + } + + result = v9fs_t_open(v9ses, newfid, open_mode, &fcall); + if (result < 0) { + dprintk(DEBUG_ERROR, + "open failed, open_mode 0x%x: %s\n", open_mode, + FCALL_ERROR(fcall)); + kfree(fcall); + return result; + } + + iounit = fcall->params.ropen.iounit; + kfree(fcall); + } + + + file->private_data = v9fid; + + v9fid->rdir_pos = 0; + v9fid->rdir_fcall = NULL; + v9fid->fidopen = 1; + v9fid->filp = file; + v9fid->iounit = iounit; + + return 0; +} + +/** + * v9fs_file_lock - lock a file (or directory) + * @inode: inode to be opened + * @file: file being opened + * + * XXX - this looks like a local only lock, we should extend into 9P + * by using open exclusive + */ + +static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl) +{ + int res = 0; + struct inode *inode = filp->f_dentry->d_inode; + + dprintk(DEBUG_VFS, "filp: %p lock: %p\n", filp, fl); + + /* No mandatory locks */ + if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID) + return -ENOLCK; + + if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { + filemap_fdatawrite(inode->i_mapping); + filemap_fdatawait(inode->i_mapping); + invalidate_inode_pages(&inode->i_data); + } + + return res; +} + +/** + * v9fs_read - read from a file (internal) + * @filep: file pointer to read + * @data: data buffer to read data into + * @count: size of buffer + * @offset: offset at which to read data + * + */ + +static ssize_t +v9fs_read(struct file *filp, char *buffer, size_t count, loff_t * offset) +{ + struct inode *inode = filp->f_dentry->d_inode; + struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); + struct v9fs_fid *v9f = filp->private_data; + struct v9fs_fcall *fcall = NULL; + int fid = v9f->fid; + int rsize = 0; + int result = 0; + int total = 0; + + dprintk(DEBUG_VFS, "\n"); + + rsize = v9ses->maxdata - V9FS_IOHDRSZ; + if (v9f->iounit != 0 && rsize > v9f->iounit) + rsize = v9f->iounit; + + do { + if (count < rsize) + rsize = count; + + result = v9fs_t_read(v9ses, fid, *offset, rsize, &fcall); + + if (result < 0) { + printk(KERN_ERR "9P2000: v9fs_t_read returned %d\n", + result); + + kfree(fcall); + return total; + } else + *offset += result; + + /* XXX - extra copy */ + memcpy(buffer, fcall->params.rread.data, result); + count -= result; + buffer += result; + total += result; + + kfree(fcall); + + if (result < rsize) + break; + } while (count); + + return total; +} + +/** + * v9fs_file_read - read from a file + * @filep: file pointer to read + * @data: data buffer to read data into + * @count: size of buffer + * @offset: offset at which to read data + * + */ + +static ssize_t +v9fs_file_read(struct file *filp, char __user * data, size_t count, + loff_t * offset) +{ + int retval = -1; + int ret = 0; + char *buffer; + + buffer = kmalloc(count, GFP_KERNEL); + if (!buffer) + return -ENOMEM; + + retval = v9fs_read(filp, buffer, count, offset); + if (retval > 0) { + if ((ret = copy_to_user(data, buffer, retval)) != 0) { + dprintk(DEBUG_ERROR, "Problem copying to user %d\n", + ret); + retval = ret; + } + } + + kfree(buffer); + + return retval; +} + +/** + * v9fs_write - write to a file + * @filep: file pointer to write + * @data: data buffer to write data from + * @count: size of buffer + * @offset: offset at which to write data + * + */ + +static ssize_t +v9fs_write(struct file *filp, char *buffer, size_t count, loff_t * offset) +{ + struct inode *inode = filp->f_dentry->d_inode; + struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); + struct v9fs_fid *v9fid = filp->private_data; + struct v9fs_fcall *fcall; + int fid = v9fid->fid; + int result = -EIO; + int rsize = 0; + int total = 0; + + dprintk(DEBUG_VFS, "data %p count %d offset %x\n", buffer, (int)count, + (int)*offset); + rsize = v9ses->maxdata - V9FS_IOHDRSZ; + if (v9fid->iounit != 0 && rsize > v9fid->iounit) + rsize = v9fid->iounit; + + dump_data(buffer, count); + + do { + if (count < rsize) + rsize = count; + + result = + v9fs_t_write(v9ses, fid, *offset, rsize, buffer, &fcall); + if (result < 0) { + eprintk(KERN_ERR, "error while writing: %s(%d)\n", + FCALL_ERROR(fcall), result); + kfree(fcall); + return result; + } else + *offset += result; + + kfree(fcall); + + if (result != rsize) { + eprintk(KERN_ERR, + "short write: v9fs_t_write returned %d\n", + result); + break; + } + + count -= result; + buffer += result; + total += result; + } while (count); + + return total; +} + +/** + * v9fs_file_write - write to a file + * @filep: file pointer to write + * @data: data buffer to write data from + * @count: size of buffer + * @offset: offset at which to write data + * + */ + +static ssize_t +v9fs_file_write(struct file *filp, const char __user * data, + size_t count, loff_t * offset) +{ + int ret = -1; + char *buffer; + + buffer = kmalloc(count, GFP_KERNEL); + if (buffer == NULL) + return -ENOMEM; + + ret = copy_from_user(buffer, data, count); + if (ret) { + dprintk(DEBUG_ERROR, "Problem copying from user\n"); + ret = -EFAULT; + } else { + ret = v9fs_write(filp, buffer, count, offset); + } + + kfree(buffer); + + return ret; +} + +struct file_operations v9fs_file_operations = { + .llseek = generic_file_llseek, + .read = v9fs_file_read, + .write = v9fs_file_write, + .open = v9fs_file_open, + .release = v9fs_dir_release, + .lock = v9fs_file_lock, +};