From e44163e177960ee60e32a73bffdd53c3a5827406 Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Mon, 15 Jun 2015 09:41:18 -0400 Subject: btrfs: explictly delete unused block groups in close_ctree and ro-remount 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 Reviewed-by: Filipe Manana Tested-by: Filipe Manana Signed-off-by: Chris Mason --- fs/btrfs/super.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'fs/btrfs/super.c') diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index cd7ef34..a1077e0 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1650,6 +1650,17 @@ 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); -- cgit v1.1