Two patches to improve RBD exclusive lock interaction with

osd_request_timeout option and another fix to reduce the potential for
 erroneous blocklisting -- this time in CephFS.  All going to stable.
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Merge tag 'ceph-for-6.5-rc5' of https://github.com/ceph/ceph-client

Pull ceph fixes from Ilya Dryomov:
 "Two patches to improve RBD exclusive lock interaction with
  osd_request_timeout option and another fix to reduce the potential for
  erroneous blocklisting -- this time in CephFS. All going to stable"

* tag 'ceph-for-6.5-rc5' of https://github.com/ceph/ceph-client:
  libceph: fix potential hang in ceph_osdc_notify()
  rbd: prevent busy loop when requesting exclusive lock
  ceph: defer stopping mdsc delayed_work

drivers/block/rbd.c

@@ -3675,7 +3675,7 @@ static int rbd_lock(struct rbd_device *rbd_dev)
 	ret = ceph_cls_lock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
 			    RBD_LOCK_NAME, CEPH_CLS_LOCK_EXCLUSIVE, cookie,
 			    RBD_LOCK_TAG, "", 0);
-	if (ret)
+	if (ret && ret != -EEXIST)
 		return ret;
 
 	__rbd_lock(rbd_dev, cookie);
@@ -3878,7 +3878,7 @@ static struct ceph_locker *get_lock_owner_info(struct rbd_device *rbd_dev)
 				 &rbd_dev->header_oloc, RBD_LOCK_NAME,
 				 &lock_type, &lock_tag, &lockers, &num_lockers);
 	if (ret) {
-		rbd_warn(rbd_dev, "failed to retrieve lockers: %d", ret);
+		rbd_warn(rbd_dev, "failed to get header lockers: %d", ret);
 		return ERR_PTR(ret);
 	}
 
@@ -3940,8 +3940,10 @@ static int find_watcher(struct rbd_device *rbd_dev,
 	ret = ceph_osdc_list_watchers(osdc, &rbd_dev->header_oid,
 				      &rbd_dev->header_oloc, &watchers,
 				      &num_watchers);
-	if (ret)
+	if (ret) {
+		rbd_warn(rbd_dev, "failed to get watchers: %d", ret);
 		return ret;
+	}
 
 	sscanf(locker->id.cookie, RBD_LOCK_COOKIE_PREFIX " %llu", &cookie);
 	for (i = 0; i < num_watchers; i++) {
@@ -3985,8 +3987,12 @@ static int rbd_try_lock(struct rbd_device *rbd_dev)
 		locker = refreshed_locker = NULL;
 
 		ret = rbd_lock(rbd_dev);
-		if (ret != -EBUSY)
+		if (!ret)
 			goto out;
+		if (ret != -EBUSY) {
+			rbd_warn(rbd_dev, "failed to lock header: %d", ret);
+			goto out;
+		}
 
 		/* determine if the current lock holder is still alive */
 		locker = get_lock_owner_info(rbd_dev);
@@ -4089,11 +4095,8 @@ static int rbd_try_acquire_lock(struct rbd_device *rbd_dev)
 
 	ret = rbd_try_lock(rbd_dev);
 	if (ret < 0) {
-		rbd_warn(rbd_dev, "failed to lock header: %d", ret);
-		if (ret == -EBLOCKLISTED)
-			goto out;
-
-		ret = 1; /* request lock anyway */
+		rbd_warn(rbd_dev, "failed to acquire lock: %d", ret);
+		goto out;
 	}
 	if (ret > 0) {
 		up_write(&rbd_dev->lock_rwsem);
@@ -6627,12 +6630,11 @@ static int rbd_add_acquire_lock(struct rbd_device *rbd_dev)
 		cancel_delayed_work_sync(&rbd_dev->lock_dwork);
 		if (!ret)
 			ret = -ETIMEDOUT;
-	}
 
-	if (ret) {
-		rbd_warn(rbd_dev, "failed to acquire exclusive lock: %ld", ret);
-		return ret;
+		rbd_warn(rbd_dev, "failed to acquire lock: %ld", ret);
 	}
+	if (ret)
+		return ret;
 
 	/*
 	 * The lock may have been released by now, unless automatic lock

fs/ceph/mds_client.c

@@ -4764,7 +4764,7 @@ static void delayed_work(struct work_struct *work)
 
 	dout("mdsc delayed_work\n");
 
-	if (mdsc->stopping)
+	if (mdsc->stopping >= CEPH_MDSC_STOPPING_FLUSHED)
 		return;
 
 	mutex_lock(&mdsc->mutex);
@@ -4943,7 +4943,7 @@ void send_flush_mdlog(struct ceph_mds_session *s)
 void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
 {
 	dout("pre_umount\n");
-	mdsc->stopping = 1;
+	mdsc->stopping = CEPH_MDSC_STOPPING_BEGIN;
 
 	ceph_mdsc_iterate_sessions(mdsc, send_flush_mdlog, true);
 	ceph_mdsc_iterate_sessions(mdsc, lock_unlock_session, false);

fs/ceph/mds_client.h

@@ -380,6 +380,11 @@ struct cap_wait {
 	int			want;
 };
 
+enum {
+       CEPH_MDSC_STOPPING_BEGIN = 1,
+       CEPH_MDSC_STOPPING_FLUSHED = 2,
+};
+
 /*
  * mds client state
  */

fs/ceph/super.c

@@ -1374,6 +1374,16 @@ static void ceph_kill_sb(struct super_block *s)
 	ceph_mdsc_pre_umount(fsc->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(s);
+
+	fsc->mdsc->stopping = CEPH_MDSC_STOPPING_FLUSHED;
+
 	kill_anon_super(s);
 
 	fsc->client->extra_mon_dispatch = NULL;

net/ceph/osd_client.c

@@ -3334,17 +3334,24 @@ static int linger_reg_commit_wait(struct ceph_osd_linger_request *lreq)
 	int ret;
 
 	dout("%s lreq %p linger_id %llu\n", __func__, lreq, lreq->linger_id);
-	ret = wait_for_completion_interruptible(&lreq->reg_commit_wait);
+	ret = wait_for_completion_killable(&lreq->reg_commit_wait);
 	return ret ?: lreq->reg_commit_error;
 }
 
-static int linger_notify_finish_wait(struct ceph_osd_linger_request *lreq)
+static int linger_notify_finish_wait(struct ceph_osd_linger_request *lreq,
+				     unsigned long timeout)
 {
-	int ret;
+	long left;
 
 	dout("%s lreq %p linger_id %llu\n", __func__, lreq, lreq->linger_id);
-	ret = wait_for_completion_interruptible(&lreq->notify_finish_wait);
-	return ret ?: lreq->notify_finish_error;
+	left = wait_for_completion_killable_timeout(&lreq->notify_finish_wait,
+						ceph_timeout_jiffies(timeout));
+	if (left <= 0)
+		left = left ?: -ETIMEDOUT;
+	else
+		left = lreq->notify_finish_error; /* completed */
+
+	return left;
 }
 
 /*
@@ -4896,7 +4903,8 @@ int ceph_osdc_notify(struct ceph_osd_client *osdc,
 	linger_submit(lreq);
 	ret = linger_reg_commit_wait(lreq);
 	if (!ret)
-		ret = linger_notify_finish_wait(lreq);
+		ret = linger_notify_finish_wait(lreq,
+				 msecs_to_jiffies(2 * timeout * MSEC_PER_SEC));
 	else
 		dout("lreq %p failed to initiate notify %d\n", lreq, ret);