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authorMichel Lespinasse <walken@google.com>2012-03-26 17:32:44 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-04-02 09:53:04 -0700
commitd27e4c282e8445be329e4e3544ea5e9d4dfdc953 (patch)
treee5c1f1d53876bed65b519c2039c9b682a89eb7eb /fs/dcache.c
parentac35405d20c0bd438cea6e9dddd84335370c739e (diff)
vfs: fix d_ancestor() case in d_materialize_unique
commit b18dafc86bb879d2f38a1743985d7ceb283c2f4d upstream. In d_materialise_unique() there are 3 subcases to the 'aliased dentry' case; in two subcases the inode i_lock is properly released but this does not occur in the -ELOOP subcase. This seems to have been introduced by commit 1836750115f2 ("fix loop checks in d_materialise_unique()"). Signed-off-by: Michel Lespinasse <walken@google.com> [ Added a comment, and moved the unlock to where we generate the -ELOOP, which seems to be more natural. You probably can't actually trigger this without a buggy network file server - d_materialize_unique() is for finding aliases on non-local filesystems, and the d_ancestor() case is for a hardlinked directory loop. But we should be robust in the case of such buggy servers anyway. ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/dcache.c')
-rw-r--r--fs/dcache.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/dcache.c b/fs/dcache.c
index f7908aef484..eb723d31704 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2357,6 +2357,7 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
if (d_ancestor(alias, dentry)) {
/* Check for loops */
actual = ERR_PTR(-ELOOP);
+ spin_unlock(&inode->i_lock);
} else if (IS_ROOT(alias)) {
/* Is this an anonymous mountpoint that we
* could splice into our tree? */
@@ -2366,7 +2367,7 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
goto found;
} else {
/* Nope, but we must(!) avoid directory
- * aliasing */
+ * aliasing. This drops inode->i_lock */
actual = __d_unalias(inode, dentry, alias);
}
write_sequnlock(&rename_lock);