Btrfs: send, add missing error check for calls to path_loop()

The function path_loop() can return a negative integer, signaling an
error, 0 if there's no path loop and 1 if there's a path loop. We were
treating any non zero values as meaning that a path loop exists. Fix
this by explicitly checking for errors and gracefully return them to
user space.

Signed-off-by: Filipe Manana <fdmanana@suse.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 993e1bab0a6b..0dc05bb856ff 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -3200,6 +3200,8 @@ static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
 
         sctx->send_progress = sctx->cur_ino + 1;
         ret = path_loop(sctx, name, pm->ino, pm->gen, &ancestor);
+        if (ret < 0)
+                goto out;
         if (ret) {
                 LIST_HEAD(deleted_refs);
                 ASSERT(ancestor > BTRFS_FIRST_FREE_OBJECTID);