[PATCH 3.18 15/19] btrfs: resume qgroup rescan on rw remount

Path	csiph.com!news.mixmin.net!aioe.org!bofh.it!news.nic.it!robomod
From	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Newsgroups	linux.kernel
Subject	[PATCH 3.18 15/19] btrfs: resume qgroup rescan on rw remount
Date	Tue, 12 Sep 2017 19:00:02 +0200
Message-ID	<uoWHw-3KO-31@gated-at.bofh.it> (permalink)
References	<uoWHv-3KO-11@gated-at.bofh.it>
X-Original-To	linux-kernel@vger.kernel.org
X-Mailer	git-send-email 2.14.1
User-Agent	quilt/0.65
MIME-Version	1.0
Content-Type	text/plain; charset=UTF-8
Sender	robomod@news.nic.it
List-ID	<linux-kernel.vger.kernel.org>
X-Mailing-List	linux-kernel@vger.kernel.org
Approved	robomod@news.nic.it
Lines	42
Organization	linux.* mail to news gateway
X-Original-Cc	Greg Kroah-Hartman <gregkh@linuxfoundation.org>, stable@vger.kernel.org, Jeff Mahoney <jeffm@suse.com>, Aleksa Sarai <asarai@suse.de>, Nikolay Borisov <nborisov@suse.com>, David Sterba <dsterba@suse.com>
X-Original-Date	Tue, 12 Sep 2017 09:54:51 -0700
X-Original-Message-ID	<20170912165016.778805202@linuxfoundation.org>
X-Original-References	<20170912165016.208029904@linuxfoundation.org>
X-Original-Sender	linux-kernel-owner@vger.kernel.org
Xref	csiph.com linux.kernel:1731009

Show key headers only | View raw

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Aleksa Sarai <asarai@suse.de>

commit 6c6b5a39c4bf3dbd8cf629c9f5450e983c19dbb9 upstream.

Several distributions mount the "proper root" as ro during initrd and
then remount it as rw before pivot_root(2). Thus, if a rescan had been
aborted by a previous shutdown, the rescan would never be resumed.

This issue would manifest itself as several btrfs ioctl(2)s causing the
entire machine to hang when btrfs_qgroup_wait_for_completion was hit
(due to the fs_info->qgroup_rescan_running flag being set but the rescan
itself not being resumed). Notably, Docker's btrfs storage driver makes
regular use of BTRFS_QUOTA_CTL_DISABLE and BTRFS_IOC_QUOTA_RESCAN_WAIT
(causing this problem to be manifested on boot for some machines).

Cc: Jeff Mahoney <jeffm@suse.com>
Fixes: b382a324b60f ("Btrfs: fix qgroup rescan resume on mount")
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/btrfs/super.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1575,6 +1575,8 @@ static int btrfs_remount(struct super_bl
 			goto restore;
 		}
 
+		btrfs_qgroup_rescan_resume(fs_info);
+
 		if (!fs_info->uuid_root) {
 			btrfs_info(fs_info, "creating UUID tree");
 			ret = btrfs_create_uuid_tree(fs_info);

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

[PATCH 3.18 15/19] btrfs: resume qgroup rescan on rw remount Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-09-12 19:00 +0200

csiph-web