From: Al Viro Date: Fri, 29 May 2015 03:09:19 +0000 (-0400) Subject: d_walk() might skip too much X-Git-Tag: v4.0.5~102 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=06b31fdcf73f8dd0e7e30ce59800948b94e088a9;p=thirdparty%2Fkernel%2Fstable.git d_walk() might skip too much commit 2159184ea01e4ae7d15f2017e296d4bc82d5aeb0 upstream. when we find that a child has died while we'd been trying to ascend, we should go into the first live sibling itself, rather than its sibling. Off-by-one in question had been introduced in "deal with deadlock in d_walk()" and the fix needs to be backported to all branches this one has been backported to. Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/dcache.c b/fs/dcache.c index c71e3732e53bc..922f23ef60412 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1205,13 +1205,13 @@ 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; }