From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cantor2.suse.de ([195.135.220.15]:53341 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755846AbbFONlY (ORCPT ); Mon, 15 Jun 2015 09:41:24 -0400 Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 48568AD31 for ; Mon, 15 Jun 2015 13:41:23 +0000 (UTC) From: jeffm@suse.com To: linux-btrfs@vger.kernel.org Cc: Jeff Mahoney Subject: [PATCH 5/7] btrfs: explictly delete unused block groups in close_ctree and ro-remount Date: Mon, 15 Jun 2015 09:41:18 -0400 Message-Id: <1434375680-4115-5-git-send-email-jeffm@suse.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: In-Reply-To: <557ED6DC.6070900@suse.com> From: Jeff Mahoney The cleaner thread may already be sleeping by the time we enter close_ctree. If that's the case, we'll skip removing any unused block groups queued for removal, even during a normal umount. They'll be cleaned up automatically at next mount, but users expect a umount to be a clean synchronization point, especially when used on thin-provisioned storage with -odiscard. We also explicitly remove unused block groups in the ro-remount path for the same reason. Signed-off-by: Jeff Mahoney --- fs/btrfs/disk-io.c | 9 +++++++++ fs/btrfs/super.c | 11 +++++++++++ 2 files changed, 20 insertions(+) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 2ef9a4b..2e47fef 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3710,6 +3710,15 @@ void close_ctree(struct btrfs_root *root) cancel_work_sync(&fs_info->async_reclaim_work); if (!(fs_info->sb->s_flags & MS_RDONLY)) { + /* + * If the cleaner thread is stopped and there are + * block groups queued for removal, the deletion will be + * skipped when we quit the cleaner thread. + */ + mutex_lock(&root->fs_info->cleaner_mutex); + btrfs_delete_unused_bgs(root->fs_info); + mutex_unlock(&root->fs_info->cleaner_mutex); + ret = btrfs_commit_super(root); if (ret) btrfs_err(fs_info, "commit super ret %d", ret); diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 9e66f5e..2ccd8d4 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1539,6 +1539,17 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data) sb->s_flags |= MS_RDONLY; + /* + * Setting MS_RDONLY will put the cleaner thread to + * sleep at the next loop if it's already active. + * If it's already asleep, we'll leave unused block + * groups on disk until we're mounted read-write again + * unless we clean them up here. + */ + mutex_lock(&root->fs_info->cleaner_mutex); + btrfs_delete_unused_bgs(fs_info); + mutex_unlock(&root->fs_info->cleaner_mutex); + btrfs_dev_replace_suspend_for_unmount(fs_info); btrfs_scrub_cancel(fs_info); btrfs_pause_balance(fs_info); -- 2.4.3