| From | Kamal Mostafa <> | Subject | [PATCH 36/75] Btrfs: fix lock leak when resuming snapshot deletion | Date | Tue, 30 Jul 2013 11:44:40 -0700 |
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3.8.13.6 -stable review patch. If anyone has any objections, please let me know.
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From: Josef Bacik <jbacik@fusionio.com>
commit fec386ac1428f9c0e672df952cbca5cebd4e4e2f upstream.
We aren't setting path->locks[level] when we resume a snapshot deletion which means we won't unlock the buffer when we free the path. This causes deadlocks if we happen to re-allocate the block before we've evicted the extent buffer from cache. Thanks,
Reported-by: Alex Lyakas <alex.btrfs@zadarastorage.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- fs/btrfs/extent-tree.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index d170412..17cfffd 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -7023,6 +7023,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root, while (1) { btrfs_tree_lock(path->nodes[level]); btrfs_set_lock_blocking(path->nodes[level]); + path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; ret = btrfs_lookup_extent_info(trans, root, path->nodes[level]->start, @@ -7039,6 +7040,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root, break; btrfs_tree_unlock(path->nodes[level]); + path->locks[level] = 0; WARN_ON(wc->refs[level] != 1); level--; } -- 1.8.1.2
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