From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755231AbdJINUb (ORCPT ); Mon, 9 Oct 2017 09:20:31 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:43462 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755187AbdJINU0 (ORCPT ); Mon, 9 Oct 2017 09:20:26 -0400 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, "David Sterba" , "Nikolay Borisov" , "Liu Bo" Date: Mon, 09 Oct 2017 13:44:24 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 042/192] Btrfs: skip commit transaction if we don't have enough pinned bytes In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 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 3.16.49-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Liu Bo commit 28785f70ef882e4798cd5706066a55dbf7adf80e upstream. We commit transaction in order to reclaim space from pinned bytes because it could process delayed refs, and in may_commit_transaction(), we check first if pinned bytes are enough for the required space, we then check if that plus bytes reserved for delayed insert are enough for the required space. This changes the code to the above logic. Fixes: b150a4f10d87 ("Btrfs: use a percpu to keep track of possibly pinned bytes") Tested-by: Nikolay Borisov Reported-by: Nikolay Borisov Reviewed-by: Nikolay Borisov Signed-off-by: Liu Bo Signed-off-by: David Sterba Signed-off-by: Ben Hutchings --- 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 @@ -4230,7 +4230,7 @@ static int may_commit_transaction(struct spin_lock(&delayed_rsv->lock); if (percpu_counter_compare(&space_info->total_bytes_pinned, - bytes - delayed_rsv->size) >= 0) { + bytes - delayed_rsv->size) < 0) { spin_unlock(&delayed_rsv->lock); return -ENOSPC; }