From: Xiubo Li <xiubli@redhat.com>
Date: Wed, 4 Dec 2019 01:27:18 -0500
Subject: ceph: fix possible long time wait during umount
Git-commit: 07edc0571ef1b13e124b462aca8d09f79809d6dd
Patch-mainline: v5.6-rc1
References: jsc#SES-1134

During umount, if there has no any unsafe request in the mdsc and
some requests still in-flight and not got reply yet, and if the
rest requets are all safe ones, after that even all of them in mdsc
are unregistered, the umount must wait until after mount_timeout
seconds anyway.

Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Acked-by: Luis Henriques <lhenriques@suse.com>
---
 fs/ceph/mds_client.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 1b53aceb54bd..6dca3b4d03a9 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2884,6 +2884,10 @@ static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
 		set_bit(CEPH_MDS_R_GOT_SAFE, &req->r_req_flags);
 		__unregister_request(mdsc, req);
 
+		/* last request during umount? */
+		if (mdsc->stopping && !__get_oldest_req(mdsc))
+			complete_all(&mdsc->safe_umount_waiters);
+
 		if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) {
 			/*
 			 * We already handled the unsafe response, now do the
@@ -2894,9 +2898,6 @@ static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
 			 */
 			dout("got safe reply %llu, mds%d\n", tid, mds);
 
-			/* last unsafe request during umount? */
-			if (mdsc->stopping && !__get_oldest_req(mdsc))
-				complete_all(&mdsc->safe_umount_waiters);
 			mutex_unlock(&mdsc->mutex);
 			goto out;
 		}