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authorJosef Bacik <josef@toxicpanda.com>2019-03-06 17:13:04 -0500
committerDavid Sterba <dsterba@suse.com>2019-03-13 17:13:32 +0100
commit2cc8334270e281815c3850c3adea363c51f21e0d (patch)
tree4d0dbb78a4c8e8ecd04f0b598d703330fc4462d9 /fs/btrfs
parentbf504110bc8aa05df48b0e5f0aa84bfb81e0574b (diff)
btrfs: remove WARN_ON in log_dir_items
When Filipe added the recursive directory logging stuff in 2f2ff0ee5e430 ("Btrfs: fix metadata inconsistencies after directory fsync") he specifically didn't take the directory i_mutex for the children directories that we need to log because of lockdep. This is generally fine, but can lead to this WARN_ON() tripping if we happen to run delayed deletion's in between our first search and our second search of dir_item/dir_indexes for this directory. We expect this to happen, so the WARN_ON() isn't necessary. Drop the WARN_ON() and add a comment so we know why this case can happen. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/tree-log.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 5256cddf3a43..960ea49a7a0f 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -3578,9 +3578,16 @@ static noinline int log_dir_items(struct btrfs_trans_handle *trans,
}
btrfs_release_path(path);
- /* find the first key from this transaction again */
+ /*
+ * Find the first key from this transaction again. See the note for
+ * log_new_dir_dentries, if we're logging a directory recursively we
+ * won't be holding its i_mutex, which means we can modify the directory
+ * while we're logging it. If we remove an entry between our first
+ * search and this search we'll not find the key again and can just
+ * bail.
+ */
ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
- if (WARN_ON(ret != 0))
+ if (ret != 0)
goto done;
/*