On Thu, Jun 9, 2022 at 11:19 AM Xiubo Li <xiubli@xxxxxxxxxx> wrote: > > > On 6/9/22 10:15 AM, Yan, Zheng wrote: > > The recent series of patches that add "wait on async xxxx" at various > > places do not seem correct. The correct fix should make mds avoid any > > wait when handling async requests. > > > In this case I am thinking what will happen if the async create request > is deferred, then the cap flush related request should fail to find the > ino. > > Should we wait ? Then how to distinguish from migrating a subtree and a > deferred async create cases ? > async op caps are revoked at freezingtree stage of subtree migration. see Locker::invalidate_lock_caches > > > On Wed, Jun 8, 2022 at 12:56 PM Jeff Layton <jlayton@xxxxxxxxxx> wrote: > >> Currently, we'll call ceph_check_caps, but if we're still waiting on the > >> reply, we'll end up spinning around on the same inode in > >> flush_dirty_session_caps. Wait for the async create reply before > >> flushing caps. > >> > >> Fixes: fbed7045f552 (ceph: wait for async create reply before sending any cap messages) > >> URL: https://tracker.ceph.com/issues/55823 > >> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> > >> --- > >> fs/ceph/caps.c | 1 + > >> 1 file changed, 1 insertion(+) > >> > >> I don't know if this will fix the tx queue stalls completely, but I > >> haven't seen one with this patch in place. I think it makes sense on its > >> own, either way. > >> > >> diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c > >> index 0a48bf829671..5ecfff4b37c9 100644 > >> --- a/fs/ceph/caps.c > >> +++ b/fs/ceph/caps.c > >> @@ -4389,6 +4389,7 @@ static void flush_dirty_session_caps(struct ceph_mds_session *s) > >> ihold(inode); > >> dout("flush_dirty_caps %llx.%llx\n", ceph_vinop(inode)); > >> spin_unlock(&mdsc->cap_dirty_lock); > >> + ceph_wait_on_async_create(inode); > >> ceph_check_caps(ci, CHECK_CAPS_FLUSH, NULL); > >> iput(inode); > >> spin_lock(&mdsc->cap_dirty_lock); > >> -- > >> 2.36.1 > >> >
