Commit 94ab45b5 authored by Andrew Morton's avatar Andrew Morton Committed by Vojtech Pavlik

[PATCH] xattr: lock_kernel() balancing fix

Patch from Andreas Gruenbacher <agruen@suse.de>

This patch fixes an unbalanced lock_kernel()/unlock_kernel() path in the ext3
extended attributes code.  Instead of fixing this in fs/ext3/xattr_user.c,
the locking code is moved to fs/ext3/xattr.c, since most other types of
extended attributes will need the exact same functionality.
parent 2743f6fe
......@@ -88,7 +88,8 @@
# define ea_bdebug(f...)
#endif
static int ext3_xattr_set2(handle_t *, struct inode *, struct buffer_head *,
static int ext3_xattr_set_handle2(handle_t *, struct inode *,
struct buffer_head *,
struct ext3_xattr_header *);
static int ext3_xattr_cache_insert(struct buffer_head *);
......@@ -459,7 +460,7 @@ static void ext3_xattr_update_super_block(handle_t *handle,
}
/*
* ext3_xattr_set()
* ext3_xattr_set_handle()
*
* Create, replace or remove an extended attribute for this inode. Buffer
* is NULL to remove an existing extended attribute, and non-NULL to
......@@ -471,8 +472,9 @@ static void ext3_xattr_update_super_block(handle_t *handle,
* Returns 0, or a negative error number on failure.
*/
int
ext3_xattr_set(handle_t *handle, struct inode *inode, int name_index,
const char *name, const void *value, size_t value_len, int flags)
ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
const char *name, const void *value, size_t value_len,
int flags)
{
struct super_block *sb = inode->i_sb;
struct buffer_head *bh = NULL;
......@@ -673,7 +675,8 @@ bad_block: ext3_error(sb, "ext3_xattr_set",
/* Remove this attribute. */
if (EXT3_XATTR_NEXT(ENTRY(header+1)) == last) {
/* This block is now empty. */
error = ext3_xattr_set2(handle, inode, bh,NULL);
error = ext3_xattr_set_handle2(handle, inode,
bh, NULL);
goto cleanup;
} else {
/* Remove the old name. */
......@@ -701,7 +704,7 @@ bad_block: ext3_error(sb, "ext3_xattr_set",
}
ext3_xattr_rehash(header, here);
error = ext3_xattr_set2(handle, inode, bh, header);
error = ext3_xattr_set_handle2(handle, inode, bh, header);
cleanup:
brelse(bh);
......@@ -713,11 +716,12 @@ bad_block: ext3_error(sb, "ext3_xattr_set",
}
/*
* Second half of ext3_xattr_set(): Update the file system.
* Second half of ext3_xattr_set_handle(): Update the file system.
*/
static int
ext3_xattr_set2(handle_t *handle, struct inode *inode,
struct buffer_head *old_bh, struct ext3_xattr_header *header)
ext3_xattr_set_handle2(handle_t *handle, struct inode *inode,
struct buffer_head *old_bh,
struct ext3_xattr_header *header)
{
struct super_block *sb = inode->i_sb;
struct buffer_head *new_bh = NULL;
......@@ -831,6 +835,34 @@ ext3_xattr_set2(handle_t *handle, struct inode *inode,
return error;
}
/*
* ext3_xattr_set()
*
* Like ext3_xattr_set_handle, but start from an inode. This extended
* attribute modification is a filesystem transaction by itself.
*
* Returns 0, or a negative error number on failure.
*/
int
ext3_xattr_set(struct inode *inode, int name_index, const char *name,
const void *value, size_t value_len, int flags)
{
handle_t *handle;
int error;
lock_kernel();
handle = ext3_journal_start(inode, EXT3_XATTR_TRANS_BLOCKS);
if (IS_ERR(handle))
error = PTR_ERR(handle);
else
error = ext3_xattr_set_handle(handle, inode, name_index, name,
value, value_len, flags);
ext3_journal_stop(handle, inode);
unlock_kernel();
return error;
}
/*
* ext3_xattr_delete_inode()
*
......
......@@ -73,7 +73,8 @@ extern int ext3_removexattr(struct dentry *, const char *);
extern int ext3_xattr_get(struct inode *, int, const char *, void *, size_t);
extern int ext3_xattr_list(struct inode *, char *, size_t);
extern int ext3_xattr_set(handle_t *handle, struct inode *, int, const char *, const void *, size_t, int);
extern int ext3_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
extern int ext3_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
extern void ext3_xattr_delete_inode(handle_t *, struct inode *);
extern void ext3_xattr_put_super(struct super_block *);
......@@ -101,7 +102,14 @@ ext3_xattr_list(struct inode *inode, void *buffer, size_t size, int flags)
}
static inline int
ext3_xattr_set(handle_t *handle, struct inode *inode, int name_index,
ext3_xattr_set(struct inode *inode, int name_index, const char *name,
const void *value, size_t size, int flags)
{
return -EOPNOTSUPP;
}
static inline int
ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
const char *name, const void *value, size_t size, int flags)
{
return -EOPNOTSUPP;
......
......@@ -61,7 +61,6 @@ static int
ext3_xattr_user_set(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
handle_t *handle;
int error;
if (strcmp(name, "") == 0)
......@@ -79,16 +78,9 @@ ext3_xattr_user_set(struct inode *inode, const char *name,
if (error)
return error;
lock_kernel();
handle = ext3_journal_start(inode, EXT3_XATTR_TRANS_BLOCKS);
if (IS_ERR(handle))
return PTR_ERR(handle);
error = ext3_xattr_set(handle, inode, EXT3_XATTR_INDEX_USER, name,
return ext3_xattr_set(inode, EXT3_XATTR_INDEX_USER, name,
value, size, flags);
ext3_journal_stop(handle, inode);
unlock_kernel();
return error;
}
struct ext3_xattr_handler ext3_xattr_user_handler = {
......
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