btrfs: fix lost error handling when looking up extended ref on log replay

During log replay, when processing inode references, if we get an error
when looking up for an extended reference at __add_inode_ref(), we ignore
it and proceed, returning success (0) if no other error happens after the
lookup. This is obviously wrong because in case an extended reference
exists and it encodes some name not in the log, we need to unlink it,
otherwise the filesystem state will not match the state it had after the
last fsync.

So just make __add_inode_ref() return an error it gets from the extended
reference lookup.

Fixes: b60c4f34cab4e6 ("btrfs: extended inode refs")
CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index dcf75a8daa200be8f013f77690da91986e2a4367..c1fdd6ef3f4aafa44eb0a15f3d64cfd17c6bd810 100644 (file)
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -1146,7 +1146,9 @@ again:
        extref = btrfs_lookup_inode_extref(NULL, root, path, name, namelen,
                                           inode_objectid, parent_objectid, 0,
                                           0);
-       if (!IS_ERR_OR_NULL(extref)) {
+       if (IS_ERR(extref)) {
+               return PTR_ERR(extref);
+       } else if (extref) {
                u32 item_size;
                u32 cur_offset = 0;
                unsigned long base;