From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:39016 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753843AbdHIQyJ (ORCPT ); Wed, 9 Aug 2017 12:54:09 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christoph Anton Mitterer , Josef Bacik , Omar Sandoval , David Sterba , Nikolay Borisov Subject: [PATCH 4.12 053/106] Btrfs: fix early ENOSPC due to delalloc Date: Wed, 9 Aug 2017 09:52:37 -0700 Message-Id: <20170809164523.891231394@linuxfoundation.org> In-Reply-To: <20170809164515.714288642@linuxfoundation.org> References: <20170809164515.714288642@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Omar Sandoval commit 17024ad0a0fdfcfe53043afb969b813d3e020c21 upstream. If a lot of metadata is reserved for outstanding delayed allocations, we rely on shrink_delalloc() to reclaim metadata space in order to fulfill reservation tickets. However, shrink_delalloc() has a shortcut where if it determines that space can be overcommitted, it will stop early. This made sense before the ticketed enospc system, but now it means that shrink_delalloc() will often not reclaim enough space to fulfill any tickets, leading to an early ENOSPC. (Reservation tickets don't care about being able to overcommit, they need every byte accounted for.) Fix it by getting rid of the shortcut so that shrink_delalloc() reclaims all of the metadata it is supposed to. This fixes early ENOSPCs we were seeing when doing a btrfs receive to populate a new filesystem, as well as early ENOSPCs Christoph saw when doing a big cp -r onto Btrfs. Fixes: 957780eb2788 ("Btrfs: introduce ticketed enospc infrastructure") Tested-by: Christoph Anton Mitterer Reviewed-by: Josef Bacik Signed-off-by: Omar Sandoval Signed-off-by: David Sterba Signed-off-by: Nikolay Borisov Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/extent-tree.c | 4 ---- 1 file changed, 4 deletions(-) --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4776,10 +4776,6 @@ skip_async: else flush = BTRFS_RESERVE_NO_FLUSH; spin_lock(&space_info->lock); - if (can_overcommit(root, space_info, orig, flush)) { - spin_unlock(&space_info->lock); - break; - } if (list_empty(&space_info->tickets) && list_empty(&space_info->priority_tickets)) { spin_unlock(&space_info->lock);