diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 5c2b28ac941000fd1bfa130d301edc91425632a1..54041d9c1e25bd36a9e4097d4d2130839bababd7 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -4247,6 +4247,9 @@ void ceph_handle_caps(struct ceph_mds_session *session,
 
 	dout("handle_caps from mds%d\n", session->s_mds);
 
+	if (!ceph_inc_mds_stopping_blocker(mdsc, session))
+		return;
+
 	/* decode */
 	end = msg->front.iov_base + msg->front.iov_len;
 	if (msg->front.iov_len < sizeof(*h))
@@ -4348,7 +4351,6 @@ void ceph_handle_caps(struct ceph_mds_session *session,
 	     vino.snap, inode);
 
 	mutex_lock(&session->s_mutex);
-	inc_session_sequence(session);
 	dout(" mds%d seq %lld cap seq %u\n", session->s_mds, session->s_seq,
 	     (unsigned)seq);
 
@@ -4457,6 +4459,8 @@ void ceph_handle_caps(struct ceph_mds_session *session,
 done_unlocked:
 	iput(inode);
 out:
+	ceph_dec_mds_stopping_blocker(mdsc);
+
 	ceph_put_string(extra_info.pool_ns);
 
 	/* Defer closing the sessions after s_mutex lock being released */
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index c257d75c575799726a1632db0e1332e9304c9582..04a881343e43eb8c25d18353781671b52339369e 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -4889,6 +4889,9 @@ static void handle_lease(struct ceph_mds_client *mdsc,
 
 	dout("handle_lease from mds%d\n", mds);
 
+	if (!ceph_inc_mds_stopping_blocker(mdsc, session))
+		return;
+
 	/* decode */
 	if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
 		goto bad;
@@ -4907,8 +4910,6 @@ static void handle_lease(struct ceph_mds_client *mdsc,
 	     dname.len, dname.name);
 
 	mutex_lock(&session->s_mutex);
-	inc_session_sequence(session);
-
 	if (!inode) {
 		dout("handle_lease no inode %llx\n", vino.ino);
 		goto release;
@@ -4970,9 +4971,13 @@ static void handle_lease(struct ceph_mds_client *mdsc,
 out:
 	mutex_unlock(&session->s_mutex);
 	iput(inode);
+
+	ceph_dec_mds_stopping_blocker(mdsc);
 	return;
 
 bad:
+	ceph_dec_mds_stopping_blocker(mdsc);
+
 	pr_err("corrupt lease message\n");
 	ceph_msg_dump(msg);
 }
@@ -5168,6 +5173,9 @@ int ceph_mdsc_init(struct ceph_fs_client *fsc)
 	}
 
 	init_completion(&mdsc->safe_umount_waiters);
+	spin_lock_init(&mdsc->stopping_lock);
+	atomic_set(&mdsc->stopping_blockers, 0);
+	init_completion(&mdsc->stopping_waiter);
 	init_waitqueue_head(&mdsc->session_close_wq);
 	INIT_LIST_HEAD(&mdsc->waiting_for_map);
 	mdsc->quotarealms_inodes = RB_ROOT;
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index 0477388a0d1c2f59b8e0cbcfc141c2656d5dfbb1..1fa0f78b7b79a7b8db7fff094d6671963e379c10 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -399,8 +399,9 @@ struct cap_wait {
 };
 
 enum {
-       CEPH_MDSC_STOPPING_BEGIN = 1,
-       CEPH_MDSC_STOPPING_FLUSHED = 2,
+	CEPH_MDSC_STOPPING_BEGIN = 1,
+	CEPH_MDSC_STOPPING_FLUSHING = 2,
+	CEPH_MDSC_STOPPING_FLUSHED = 3,
 };
 
 /*
@@ -419,7 +420,11 @@ struct ceph_mds_client {
 	struct ceph_mds_session **sessions;    /* NULL for mds if no session */
 	atomic_t		num_sessions;
 	int                     max_sessions;  /* len of sessions array */
-	int                     stopping;      /* true if shutting down */
+
+	spinlock_t              stopping_lock;  /* protect snap_empty */
+	int                     stopping;      /* the stage of shutting down */
+	atomic_t                stopping_blockers;
+	struct completion	stopping_waiter;
 
 	atomic64_t		quotarealms_count; /* # realms with quota */
 	/*
diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c
index 64592adfe48fbc70a31d100f260f7e1bb68368da..f7fcf7f08ec64270319d7644d5fbf9a2d7ab7e9f 100644
--- a/fs/ceph/quota.c
+++ b/fs/ceph/quota.c
@@ -47,25 +47,23 @@ void ceph_handle_quota(struct ceph_mds_client *mdsc,
 	struct inode *inode;
 	struct ceph_inode_info *ci;
 
+	if (!ceph_inc_mds_stopping_blocker(mdsc, session))
+		return;
+
 	if (msg->front.iov_len < sizeof(*h)) {
 		pr_err("%s corrupt message mds%d len %d\n", __func__,
 		       session->s_mds, (int)msg->front.iov_len);
 		ceph_msg_dump(msg);
-		return;
+		goto out;
 	}
 
-	/* increment msg sequence number */
-	mutex_lock(&session->s_mutex);
-	inc_session_sequence(session);
-	mutex_unlock(&session->s_mutex);
-
 	/* lookup inode */
 	vino.ino = le64_to_cpu(h->ino);
 	vino.snap = CEPH_NOSNAP;
 	inode = ceph_find_inode(sb, vino);
 	if (!inode) {
 		pr_warn("Failed to find inode %llu\n", vino.ino);
-		return;
+		goto out;
 	}
 	ci = ceph_inode(inode);
 
@@ -78,6 +76,8 @@ void ceph_handle_quota(struct ceph_mds_client *mdsc,
 	spin_unlock(&ci->i_ceph_lock);
 
 	iput(inode);
+out:
+	ceph_dec_mds_stopping_blocker(mdsc);
 }
 
 static struct ceph_quotarealm_inode *
diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
index 343d738448dcd9e8c55d5dec2b67eca554334a99..7ddc6bad77ef3f6d04432a1a3608ebdabe10fcec 100644
--- a/fs/ceph/snap.c
+++ b/fs/ceph/snap.c
@@ -1015,6 +1015,9 @@ void ceph_handle_snap(struct ceph_mds_client *mdsc,
 	int locked_rwsem = 0;
 	bool close_sessions = false;
 
+	if (!ceph_inc_mds_stopping_blocker(mdsc, session))
+		return;
+
 	/* decode */
 	if (msg->front.iov_len < sizeof(*h))
 		goto bad;
@@ -1030,10 +1033,6 @@ void ceph_handle_snap(struct ceph_mds_client *mdsc,
 	dout("%s from mds%d op %s split %llx tracelen %d\n", __func__,
 	     mds, ceph_snap_op_name(op), split, trace_len);
 
-	mutex_lock(&session->s_mutex);
-	inc_session_sequence(session);
-	mutex_unlock(&session->s_mutex);
-
 	down_write(&mdsc->snap_rwsem);
 	locked_rwsem = 1;
 
@@ -1151,6 +1150,7 @@ void ceph_handle_snap(struct ceph_mds_client *mdsc,
 	up_write(&mdsc->snap_rwsem);
 
 	flush_snaps(mdsc);
+	ceph_dec_mds_stopping_blocker(mdsc);
 	return;
 
 bad:
@@ -1160,6 +1160,8 @@ void ceph_handle_snap(struct ceph_mds_client *mdsc,
 	if (locked_rwsem)
 		up_write(&mdsc->snap_rwsem);
 
+	ceph_dec_mds_stopping_blocker(mdsc);
+
 	if (close_sessions)
 		ceph_mdsc_close_sessions(mdsc);
 	return;
diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index 75dd1b6b3d0151106780b172a91b38c42847217a..1c14d87ed871449944547cc9acf50140059bacd7 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -1462,25 +1462,90 @@ static int ceph_init_fs_context(struct fs_context *fc)
 	return -ENOMEM;
 }
 
+/*
+ * Return true if it successfully increases the blocker counter,
+ * or false if the mdsc is in stopping and flushed state.
+ */
+static bool __inc_stopping_blocker(struct ceph_mds_client *mdsc)
+{
+	spin_lock(&mdsc->stopping_lock);
+	if (mdsc->stopping >= CEPH_MDSC_STOPPING_FLUSHING) {
+		spin_unlock(&mdsc->stopping_lock);
+		return false;
+	}
+	atomic_inc(&mdsc->stopping_blockers);
+	spin_unlock(&mdsc->stopping_lock);
+	return true;
+}
+
+static void __dec_stopping_blocker(struct ceph_mds_client *mdsc)
+{
+	spin_lock(&mdsc->stopping_lock);
+	if (!atomic_dec_return(&mdsc->stopping_blockers) &&
+	    mdsc->stopping >= CEPH_MDSC_STOPPING_FLUSHING)
+		complete_all(&mdsc->stopping_waiter);
+	spin_unlock(&mdsc->stopping_lock);
+}
+
+/* For metadata IO requests */
+bool ceph_inc_mds_stopping_blocker(struct ceph_mds_client *mdsc,
+				   struct ceph_mds_session *session)
+{
+	mutex_lock(&session->s_mutex);
+	inc_session_sequence(session);
+	mutex_unlock(&session->s_mutex);
+
+	return __inc_stopping_blocker(mdsc);
+}
+
+void ceph_dec_mds_stopping_blocker(struct ceph_mds_client *mdsc)
+{
+	__dec_stopping_blocker(mdsc);
+}
+
 static void ceph_kill_sb(struct super_block *s)
 {
 	struct ceph_fs_client *fsc = ceph_sb_to_client(s);
+	struct ceph_mds_client *mdsc = fsc->mdsc;
+	bool wait;
 
 	dout("kill_sb %p\n", s);
 
-	ceph_mdsc_pre_umount(fsc->mdsc);
+	ceph_mdsc_pre_umount(mdsc);
 	flush_fs_workqueues(fsc);
 
 	/*
 	 * Though the kill_anon_super() will finally trigger the
-	 * sync_filesystem() anyway, we still need to do it here
-	 * and then bump the stage of shutdown to stop the work
-	 * queue as earlier as possible.
+	 * sync_filesystem() anyway, we still need to do it here and
+	 * then bump the stage of shutdown. This will allow us to
+	 * drop any further message, which will increase the inodes'
+	 * i_count reference counters but makes no sense any more,
+	 * from MDSs.
+	 *
+	 * Without this when evicting the inodes it may fail in the
+	 * kill_anon_super(), which will trigger a warning when
+	 * destroying the fscrypt keyring and then possibly trigger
+	 * a further crash in ceph module when the iput() tries to
+	 * evict the inodes later.
 	 */
 	sync_filesystem(s);
 
-	fsc->mdsc->stopping = CEPH_MDSC_STOPPING_FLUSHED;
+	spin_lock(&mdsc->stopping_lock);
+	mdsc->stopping = CEPH_MDSC_STOPPING_FLUSHING;
+	wait = !!atomic_read(&mdsc->stopping_blockers);
+	spin_unlock(&mdsc->stopping_lock);
+
+	if (wait && atomic_read(&mdsc->stopping_blockers)) {
+		long timeleft = wait_for_completion_killable_timeout(
+					&mdsc->stopping_waiter,
+					fsc->client->options->mount_timeout);
+		if (!timeleft) /* timed out */
+			pr_warn("umount timed out, %ld\n", timeleft);
+		else if (timeleft < 0) /* killed */
+			pr_warn("umount was killed, %ld\n", timeleft);
+	}
 
+	mdsc->stopping = CEPH_MDSC_STOPPING_FLUSHED;
 	kill_anon_super(s);
 
 	fsc->client->extra_mon_dispatch = NULL;
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index b5e54c8f010b769be8b32c9a69d5486e81741f3f..d8eb35d73a231a0390a9cfb965153ba6773e4eb7 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -1413,4 +1413,7 @@ extern bool ceph_quota_update_statfs(struct ceph_fs_client *fsc,
 				     struct kstatfs *buf);
 extern void ceph_cleanup_quotarealms_inodes(struct ceph_mds_client *mdsc);
 
+bool ceph_inc_mds_stopping_blocker(struct ceph_mds_client *mdsc,
+			       struct ceph_mds_session *session);
+void ceph_dec_mds_stopping_blocker(struct ceph_mds_client *mdsc);
 #endif /* _FS_CEPH_SUPER_H */