ceph: wait on async create before checking caps for syncfs

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.

Cc: stable@vger.kernel.org
URL: https://tracker.ceph.com/issues/55823
Fixes: fbed704 ("ceph: wait for async create reply before sending any cap messages")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/caps.c

@@ -4377,6 +4377,7 @@ 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);