From: Erqi Chen <chenerqi@gmail.com>
Date: Wed, 28 Aug 2019 21:22:45 +0800
Subject: ceph: reconnect connection if session hang in opening state
Git-commit: 71a228bc8d65900179e37ac309e678f8c523f133
Patch-mainline: v5.4-rc1
References: bsc#1153718

If client mds session is evicted in CEPH_MDS_SESSION_OPENING state,
mds won't send session msg to client, and delayed_work skip
CEPH_MDS_SESSION_OPENING state session, the session hang forever.

Allow ceph_con_keepalive to reconnect a session in OPENING to avoid
session hang. Also, ensure that we skip sessions in RESTARTING and
REJECTED states since those states can't be resurrected by issuing
a keepalive.

Link: https://tracker.ceph.com/issues/41551
Signed-off-by: Erqi Chen chenerqi@gmail.com
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-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 | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 959dcf2ab0b8..a8a8f84f3bbf 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -4088,7 +4088,9 @@ static void delayed_work(struct work_struct *work)
 				pr_info("mds%d hung\n", s->s_mds);
 			}
 		}
-		if (s->s_state < CEPH_MDS_SESSION_OPEN) {
+		if (s->s_state == CEPH_MDS_SESSION_NEW ||
+		    s->s_state == CEPH_MDS_SESSION_RESTARTING ||
+		    s->s_state == CEPH_MDS_SESSION_REJECTED) {
 			/* this mds is failed or recovering, just wait */
 			ceph_put_mds_session(s);
 			continue;