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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2009-05-16 20:12:08 +0400 |
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2009-09-14 09:18:24 +0400 |
| commit | c72e05756b900b3be24cd73a16de52bab80984c0 (patch) | |
| tree | 4fc35ad9efc1a6a9ca14baa3612e551fb4da793e /fs/reiserfs/xattr.c | |
| parent | 2ac626955ed62ee8596f00581f959cc86e6198d1 (diff) | |
| download | linux-c72e05756b900b3be24cd73a16de52bab80984c0.tar.xz | |
kill-the-bkl/reiserfs: acquire the inode mutex safely
While searching a pathname, an inode mutex can be acquired
in do_lookup() which calls reiserfs_lookup() which in turn
acquires the write lock.
On the other side reiserfs_fill_super() can acquire the write_lock
and then call reiserfs_lookup_privroot() which can acquire an
inode mutex (the root of the mount point).
So we theoretically risk an AB - BA lock inversion that could lead
to a deadlock.
As for other lock dependencies found since the bkl to mutex
conversion, the fix is to use reiserfs_mutex_lock_safe() which
drops the lock dependency to the write lock.
[ Impact: fix a possible deadlock with reiserfs ]
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Diffstat (limited to 'fs/reiserfs/xattr.c')
| -rw-r--r-- | fs/reiserfs/xattr.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c index 6925b835a43b..59870a4751cc 100644 --- a/fs/reiserfs/xattr.c +++ b/fs/reiserfs/xattr.c @@ -975,7 +975,7 @@ int reiserfs_lookup_privroot(struct super_block *s) int err = 0; /* If we don't have the privroot located yet - go find it */ - mutex_lock(&s->s_root->d_inode->i_mutex); + reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s); dentry = lookup_one_len(PRIVROOT_NAME, s->s_root, strlen(PRIVROOT_NAME)); if (!IS_ERR(dentry)) { @@ -1011,7 +1011,7 @@ int reiserfs_xattr_init(struct super_block *s, int mount_flags) if (privroot->d_inode) { s->s_xattr = reiserfs_xattr_handlers; - mutex_lock(&privroot->d_inode->i_mutex); + reiserfs_mutex_lock_safe(&privroot->d_inode->i_mutex, s); if (!REISERFS_SB(s)->xattr_root) { struct dentry *dentry; dentry = lookup_one_len(XAROOT_NAME, privroot, |