Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936400AbdCJMrg (ORCPT ); Fri, 10 Mar 2017 07:47:36 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:45024 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935826AbdCJMJh (ORCPT ); Fri, 10 Mar 2017 07:09:37 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Jon Nelson" , "David Sterba" , "Jeff Mahoney" , "Liu Bo" Date: Fri, 10 Mar 2017 11:46:22 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 147/370] btrfs: fix error handling when run_delayed_extent_op fails In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1350 Lines: 37 3.16.42-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jeff Mahoney commit aa7c8da35d1905d80e840d075f07d26ec90144b5 upstream. In __btrfs_run_delayed_refs, the error path when run_delayed_extent_op fails sets locked_ref->processing = 0 but doesn't re-increment delayed_refs->num_heads_ready. As a result, we end up triggering the WARN_ON in btrfs_select_ref_head. Fixes: d7df2c796d7 (Btrfs: attach delayed ref updates to delayed ref heads) Reported-by: Jon Nelson Signed-off-by: Jeff Mahoney Reviewed-by: Liu Bo Signed-off-by: David Sterba [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- fs/btrfs/extent-tree.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2479,7 +2479,10 @@ static noinline int __btrfs_run_delayed_ */ if (must_insert_reserved) locked_ref->must_insert_reserved = 1; + spin_lock(&delayed_refs->lock); locked_ref->processing = 0; + delayed_refs->num_heads_ready++; + spin_unlock(&delayed_refs->lock); btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret); btrfs_delayed_ref_unlock(locked_ref); return ret;