| From | lizf@kernel ... | Subject | [PATCH 3.4 115/146] d_walk() might skip too much | Date | Tue, 15 Sep 2015 17:03:50 +0800 |
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From: Al Viro <viro@zeniv.linux.org.uk>
3.4.109-rc1 review patch. If anyone has any objections, please let me know.
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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 <viro@zeniv.linux.org.uk> Signed-off-by: Zefan Li <lizefan@huawei.com> --- fs/dcache.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c index 8038a78..d071ea7 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1204,13 +1204,13 @@ ascend: /* might go back up the wrong parent if we have had a rename */ if (!locked && read_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; } -- 1.9.1
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