From: Filipe Manana <fdmanana@xxxxxxxx> [ Upstream commit eced687e224eb3cc5a501cf53ad9291337c8dbc5 ] At update_ref_for_cow() we are calling btrfs_handle_fs_error() if we find that the extent buffer has an unexpected ref count of zero, however we can simply use btrfs_abort_transaction(), which achieves the same purposes: to turn the fs to error state, abort the current transaction and turn the fs to RO mode as well. Besides that, btrfs_abort_transaction() also prints a stack trace which makes it more useful. Also, as this is a very unexpected situation, indicating a serious corruption/inconsistency, tag the if branch as 'unlikely', set the error code to -EUCLEAN instead of -EROFS, and log an explicit message. Reviewed-by: Qu Wenruo <wqu@xxxxxxxx> Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx> Reviewed-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- fs/btrfs/ctree.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index ab9f8d6c4f1b9..5d462dd5fcf56 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -309,9 +309,13 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, &refs, &flags); if (ret) return ret; - if (refs == 0) { - ret = -EROFS; - btrfs_handle_fs_error(fs_info, ret, NULL); + if (unlikely(refs == 0)) { + btrfs_crit(fs_info, + "found 0 references for tree block at bytenr %llu level %d root %llu", + buf->start, btrfs_header_level(buf), + btrfs_root_id(root)); + ret = -EUCLEAN; + btrfs_abort_transaction(trans, ret); return ret; } } else { -- 2.39.2