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authorLinus Torvalds <torvalds@linux-foundation.org>2015-05-31 16:00:34 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-05-31 16:00:34 -0700
commit8ba64dc33830fbcd57d59fddc2ca1c24a6a394c4 (patch)
treec7c5fa2b739d21752bff033d2df596a30a1d86bb
parent36a8b9a774f8f283cdf9e6959ea9b5208681e8ed (diff)
parent2159184ea01e4ae7d15f2017e296d4bc82d5aeb0 (diff)
downloadkernel-8ba64dc33830fbcd57d59fddc2ca1c24a6a394c4.tar.gz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fix from Al Viro: "Off-by-one in d_walk()/__dentry_kill() race fix. It's very hard to hit; possible in the same conditions as the original bug, except that you need the skipped branch to contain all the remaining evictables, so that the d_walk()-calling loop in d_invalidate() decides there's nothing more to do and doesn't go for another pass - otherwise that next pass will sweep the sucker. So it's not too urgent, but seeing that the fix is obvious and the original commit has spread into all -stable branches..." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: d_walk() might skip too much
-rw-r--r--fs/dcache.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/dcache.c b/fs/dcache.c
index 656ce522a218..37b5afdaf698 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1239,13 +1239,13 @@ ascend:
/* might go back up the wrong parent if we have had a rename. */
if (need_seqretry(&rename_lock, seq))
goto rename_retry;
- next = child->d_child.next;
- while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED)) {
+ /* go into the first sibling still alive */
+ do {
+ next = child->d_child.next;
if (next == &this_parent->d_subdirs)
goto ascend;
child = list_entry(next, struct dentry, d_child);
- next = next->next;
- }
+ } while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED));
rcu_read_unlock();
goto resume;
}