linux/fs/9p/vfs_super.c
Sukadev Bhattiprolu a3ec947c85 vfs: simple_set_mnt() should return void
simple_set_mnt() is defined as returning 'int' but always returns 0.
Callers assume simple_set_mnt() never fails and don't properly cleanup if
it were to _ever_ fail.  For instance, get_sb_single() and get_sb_nodev()
should:

        up_write(sb->s_unmount);
        deactivate_super(sb);

if simple_set_mnt() fails.

Since simple_set_mnt() never fails, would be cleaner if it did not
return anything.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27 14:44:03 -04:00

251 lines
5.3 KiB
C

/*
* linux/fs/9p/vfs_super.c
*
* This file contians superblock ops for 9P2000. It is intended that
* you mount this file system on directories.
*
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* 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 <linux/kernel.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/inet.h>
#include <linux/pagemap.h>
#include <linux/seq_file.h>
#include <linux/mount.h>
#include <linux/idr.h>
#include <linux/sched.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include "v9fs.h"
#include "v9fs_vfs.h"
#include "fid.h"
static void v9fs_clear_inode(struct inode *);
static const struct super_operations v9fs_super_ops;
/**
* v9fs_clear_inode - release an inode
* @inode: inode to release
*
*/
static void v9fs_clear_inode(struct inode *inode)
{
filemap_fdatawrite(inode->i_mapping);
}
/**
* v9fs_set_super - set the superblock
* @s: super block
* @data: file system specific data
*
*/
static int v9fs_set_super(struct super_block *s, void *data)
{
s->s_fs_info = data;
return set_anon_super(s, data);
}
/**
* v9fs_fill_super - populate superblock with info
* @sb: superblock
* @v9ses: session information
* @flags: flags propagated from v9fs_get_sb()
*
*/
static void
v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
int flags)
{
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
sb->s_blocksize = 1 << sb->s_blocksize_bits;
sb->s_magic = V9FS_MAGIC;
sb->s_op = &v9fs_super_ops;
sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
MS_NOATIME;
}
/**
* v9fs_get_sb - mount a superblock
* @fs_type: file system type
* @flags: mount flags
* @dev_name: device name that was mounted
* @data: mount options
* @mnt: mountpoint record to be instantiated
*
*/
static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
const char *dev_name, void *data,
struct vfsmount *mnt)
{
struct super_block *sb = NULL;
struct inode *inode = NULL;
struct dentry *root = NULL;
struct v9fs_session_info *v9ses = NULL;
struct p9_wstat *st = NULL;
int mode = S_IRWXUGO | S_ISVTX;
uid_t uid = current_fsuid();
gid_t gid = current_fsgid();
struct p9_fid *fid;
int retval = 0;
P9_DPRINTK(P9_DEBUG_VFS, " \n");
st = NULL;
v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
if (!v9ses)
return -ENOMEM;
fid = v9fs_session_init(v9ses, dev_name, data);
if (IS_ERR(fid)) {
retval = PTR_ERR(fid);
goto close_session;
}
st = p9_client_stat(fid);
if (IS_ERR(st)) {
retval = PTR_ERR(st);
goto clunk_fid;
}
sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
if (IS_ERR(sb)) {
retval = PTR_ERR(sb);
goto free_stat;
}
v9fs_fill_super(sb, v9ses, flags);
inode = v9fs_get_inode(sb, S_IFDIR | mode);
if (IS_ERR(inode)) {
retval = PTR_ERR(inode);
goto release_sb;
}
inode->i_uid = uid;
inode->i_gid = gid;
root = d_alloc_root(inode);
if (!root) {
retval = -ENOMEM;
goto release_sb;
}
sb->s_root = root;
root->d_inode->i_ino = v9fs_qid2ino(&st->qid);
v9fs_stat2inode(st, root->d_inode, sb);
v9fs_fid_add(root, fid);
p9stat_free(st);
kfree(st);
P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n");
simple_set_mnt(mnt, sb);
return 0;
release_sb:
if (sb) {
up_write(&sb->s_umount);
deactivate_super(sb);
}
free_stat:
kfree(st);
clunk_fid:
p9_client_clunk(fid);
close_session:
v9fs_session_close(v9ses);
kfree(v9ses);
return retval;
}
/**
* v9fs_kill_super - Kill Superblock
* @s: superblock
*
*/
static void v9fs_kill_super(struct super_block *s)
{
struct v9fs_session_info *v9ses = s->s_fs_info;
P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s);
v9fs_dentry_release(s->s_root); /* clunk root */
kill_anon_super(s);
v9fs_session_close(v9ses);
kfree(v9ses);
P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n");
}
/**
* v9fs_show_options - Show mount options in /proc/mounts
* @m: seq_file to write to
* @mnt: mount descriptor
*
*/
static int v9fs_show_options(struct seq_file *m, struct vfsmount *mnt)
{
struct v9fs_session_info *v9ses = mnt->mnt_sb->s_fs_info;
seq_printf(m, "%s", v9ses->options);
return 0;
}
static void
v9fs_umount_begin(struct super_block *sb)
{
struct v9fs_session_info *v9ses = sb->s_fs_info;
v9fs_session_cancel(v9ses);
}
static const struct super_operations v9fs_super_ops = {
.statfs = simple_statfs,
.clear_inode = v9fs_clear_inode,
.show_options = v9fs_show_options,
.umount_begin = v9fs_umount_begin,
};
struct file_system_type v9fs_fs_type = {
.name = "9p",
.get_sb = v9fs_get_sb,
.kill_sb = v9fs_kill_super,
.owner = THIS_MODULE,
};