From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:39176 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752769AbdARKuu (ORCPT ); Wed, 18 Jan 2017 05:50:50 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jeff Mahoney , Liu Bo , David Sterba Subject: [PATCH 4.4 35/48] btrfs: fix locking when we put back a delayed ref thats too new Date: Wed, 18 Jan 2017 11:46:44 +0100 Message-Id: <20170118104627.025238602@linuxfoundation.org> In-Reply-To: <20170118104625.550018627@linuxfoundation.org> References: <20170118104625.550018627@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeff Mahoney commit d0280996437081dd12ed1e982ac8aeaa62835ec4 upstream. In __btrfs_run_delayed_refs, when we put back a delayed ref that's too new, we have already dropped the lock on locked_ref when we set ->processing = 0. This patch keeps the lock to cover that assignment. Fixes: d7df2c796d7 (Btrfs: attach delayed ref updates to delayed ref heads) Signed-off-by: Jeff Mahoney Reviewed-by: Liu Bo Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/extent-tree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2520,11 +2520,11 @@ static noinline int __btrfs_run_delayed_ if (ref && ref->seq && btrfs_check_delayed_seq(fs_info, delayed_refs, ref->seq)) { spin_unlock(&locked_ref->lock); - btrfs_delayed_ref_unlock(locked_ref); spin_lock(&delayed_refs->lock); locked_ref->processing = 0; delayed_refs->num_heads_ready++; spin_unlock(&delayed_refs->lock); + btrfs_delayed_ref_unlock(locked_ref); locked_ref = NULL; cond_resched(); count++;