On Thu, 2021-06-03 at 09:48 -0400, Jeff Layton wrote: > I've seen some warnings when testing recently that indicate that there > are caps still delayed on the delayed list even after we've started > unmounting. > > When checking delayed caps, process the whole list if we're unmounting, > and check for delayed caps after setting the stopping var and flushing > dirty caps. > > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> > --- > fs/ceph/caps.c | 3 ++- > fs/ceph/mds_client.c | 1 + > 2 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c > index a5e93b185515..68b4c6dfe4db 100644 > --- a/fs/ceph/caps.c > +++ b/fs/ceph/caps.c > @@ -4236,7 +4236,8 @@ void ceph_check_delayed_caps(struct ceph_mds_client *mdsc) > ci = list_first_entry(&mdsc->cap_delay_list, > struct ceph_inode_info, > i_cap_delay_list); > - if ((ci->i_ceph_flags & CEPH_I_FLUSH) == 0 && > + if (!mdsc->stopping && > + (ci->i_ceph_flags & CEPH_I_FLUSH) == 0 && > time_before(jiffies, ci->i_hold_caps_max)) > break; > list_del_init(&ci->i_cap_delay_list); > diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c > index e5af591d3bd4..916af5497829 100644 > --- a/fs/ceph/mds_client.c > +++ b/fs/ceph/mds_client.c > @@ -4691,6 +4691,7 @@ void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc) > > lock_unlock_sessions(mdsc); > ceph_flush_dirty_caps(mdsc); > + ceph_check_delayed_caps(mdsc); > wait_requests(mdsc); > > /* I'm going to self-NAK this patch for now. Initially this looked good in testing, but I think it's just papering over the real problem, which is that ceph_async_iput can queue a job to a workqueue after the point where we've flushed that workqueue on umount. I think the right approach is to look at how to ensure that calling iput doesn't end up taking these coarse-grained locks so we don't need to queue it in so many codepaths. -- Jeff Layton <jlayton@xxxxxxxxxx>
