From: Josef Bacik <josef@toxicpanda.com>
Date: Fri, 12 Mar 2021 15:25:24 -0500
Subject: btrfs: handle errors in reference count manipulation in replace_path
Git-commit: 253e258c34262c50ce2622b38d2769911a9cddfd
Patch-mainline: v5.13-rc1
References: bsc#1187833

If any of the reference count manipulation stuff fails in replace_path
we need to abort the transaction, as we've modified the blocks already.
We can simply break at this point and everything will be cleaned up.

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 |   20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2052,27 +2052,39 @@ again:
 		ref.skip_qgroup = true;
 		btrfs_init_tree_ref(&ref, level - 1, src->root_key.objectid);
 		ret = btrfs_inc_extent_ref(trans, src, &ref);
-		BUG_ON(ret);
+		if (ret) {
+			btrfs_abort_transaction(trans, ret);
+			break;
+		}
 		btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, new_bytenr,
 				       blocksize, 0);
 		ref.skip_qgroup = true;
 		btrfs_init_tree_ref(&ref, level - 1, dest->root_key.objectid);
 		ret = btrfs_inc_extent_ref(trans, dest, &ref);
-		BUG_ON(ret);
+		if (ret) {
+			btrfs_abort_transaction(trans, ret);
+			break;
+		}
 
 		btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, new_bytenr,
 				       blocksize, path->nodes[level]->start);
 		btrfs_init_tree_ref(&ref, level - 1, src->root_key.objectid);
 		ref.skip_qgroup = true;
 		ret = btrfs_free_extent(trans, src, &ref);
-		BUG_ON(ret);
+		if (ret) {
+			btrfs_abort_transaction(trans, ret);
+			break;
+		}
 
 		btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, old_bytenr,
 				       blocksize, 0);
 		btrfs_init_tree_ref(&ref, level - 1, dest->root_key.objectid);
 		ref.skip_qgroup = true;
 		ret = btrfs_free_extent(trans, dest, &ref);
-		BUG_ON(ret);
+		if (ret) {
+			btrfs_abort_transaction(trans, ret);
+			break;
+		}
 
 		btrfs_unlock_up_safe(path, 0);