From: Josef Bacik <josef@toxicpanda.com>
Date: Fri, 12 Mar 2021 15:25:22 -0500
Subject: btrfs: handle btrfs_cow_block errors in replace_path
Git-commit: 45b87c5d2557a327bb702d00040cfbf2271b56ed
Patch-mainline: v5.13-rc1
References: bsc#1187833

If we error out COWing the root node when doing a replace_path then we
simply unlock and free the buffer and return the error.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Acked-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/relocation.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -1907,7 +1907,11 @@ again:
 
 	if (cow) {
 		ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
-		BUG_ON(ret);
+		if (ret) {
+			btrfs_tree_unlock(eb);
+			free_extent_buffer(eb);
+			return ret;
+		}
 	}
 	btrfs_set_lock_blocking(eb);
 
@@ -1975,7 +1979,11 @@ again:
 			if (cow) {
 				ret = btrfs_cow_block(trans, dest, eb, parent,
 						      slot, &eb);
-				BUG_ON(ret);
+				if (ret) {
+					btrfs_tree_unlock(eb);
+					free_extent_buffer(eb);
+					break;
+				}
 			}
 			btrfs_set_lock_blocking(eb);