reiserfs: journaled xattrs

Deadlocks are possible in the xattr code between the journal lock and the
xattr sems.

This patch implements journalling for xattr operations. The benefit is
twofold:
 * It gets rid of the deadlock possibility by always ensuring that xattr
   write operations are initiated inside a transaction.
 * It corrects the problem where xattr backing files aren't considered any
   differently than normal files, despite the fact they are metadata.

I discussed the added journal load with Chris Mason, and we decided that
since xattrs (versus other journal activity) is fairly rare, the introduction
of larger transactions to support journaled xattrs wouldn't be too big a deal.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jeff Mahoney 2009-03-30 14:02:39 -04:00 committed by Linus Torvalds
parent 48b32a3553
commit 0ab2621ebd
7 changed files with 159 additions and 49 deletions

View file

@ -49,7 +49,8 @@ static inline int reiserfs_acl_count(size_t size)
#ifdef CONFIG_REISERFS_FS_POSIX_ACL
struct posix_acl *reiserfs_get_acl(struct inode *inode, int type);
int reiserfs_acl_chmod(struct inode *inode);
int reiserfs_inherit_default_acl(struct inode *dir, struct dentry *dentry,
int reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th,
struct inode *dir, struct dentry *dentry,
struct inode *inode);
int reiserfs_cache_default_acl(struct inode *dir);
extern struct xattr_handler reiserfs_posix_acl_default_handler;