On Fri, Dec 15, 2017 at 09:11:31AM -0800, Darrick J. Wong wrote: > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > When we're remounting the filesystem readonly, remove all CoW > preallocations prior to going ro. If the fs goes down after the ro > remount, we never clean up the staging extents, which means xfs_check > will trip over them on a subsequent run. Practically speaking, the > next mount will clean them up too, so this is unlikely to be seen. > > Found by adding clonerange to fsstress and running xfs/017. > > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > --- > fs/xfs/xfs_super.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > > diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c > index f663022..7b6d150 100644 > --- a/fs/xfs/xfs_super.c > +++ b/fs/xfs/xfs_super.c > @@ -1369,6 +1369,14 @@ xfs_fs_remount( > > /* rw -> ro */ > if (!(mp->m_flags & XFS_MOUNT_RDONLY) && (*flags & MS_RDONLY)) { > + /* Get rid of any leftover CoW reservations... */ > + cancel_delayed_work_sync(&mp->m_cowblocks_work); > + error = xfs_icache_free_cowblocks(mp, NULL); > + if (error) { > + xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE); > + return error; > + } On rw->ro do we start the m_cowblocks_work back up? What about when we freeze the filesystem - shouldn't we clean up the cow blocks there, too? We've tried hard in the past to make freeze and rw->ro exactly the same so that if the system is powered down while frozen it comes up almost entirely clean just like a ro-remount in shutdown.... And, FWIW, this makes ro->rw and thaw essentially the same, too. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html