Merge tag 'ceph-for-4.9-rc2' of git://github.com/ceph/ceph-client

Pull Ceph fixes from Ilya Dryomov:
 "An rbd exclusive-lock edge case fix and several filesystem fixups.

  Nikolay's error path patch is tagged for stable, everything else but
  readdir vs frags race was introduced in this merge window"

* tag 'ceph-for-4.9-rc2' of git://github.com/ceph/ceph-client:
  ceph: fix non static symbol warning
  ceph: fix uninitialized dentry pointer in ceph_real_mount()
  ceph: fix readdir vs fragmentation race
  ceph: fix error handling in ceph_read_iter
  rbd: don't retry watch reregistration if header object is gone
  rbd: don't wait for the lock forever if blacklisted

1 files changed, 33 insertions, 17 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index abb71628ab61..7b274ff4632c 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -415,15 +415,15 @@ struct rbd_device {
 };
 
 /*
- * Flag bits for rbd_dev->flags.  If atomicity is required,
- * rbd_dev->lock is used to protect access.
- *
- * Currently, only the "removing" flag (which is coupled with the
- * "open_count" field) requires atomic access.
+ * Flag bits for rbd_dev->flags:
+ * - REMOVING (which is coupled with rbd_dev->open_count) is protected
+ *   by rbd_dev->lock
+ * - BLACKLISTED is protected by rbd_dev->lock_rwsem
  */
 enum rbd_dev_flags {
 	RBD_DEV_FLAG_EXISTS,	/* mapped snapshot has not been deleted */
 	RBD_DEV_FLAG_REMOVING,	/* this mapping is being removed */
+	RBD_DEV_FLAG_BLACKLISTED, /* our ceph_client is blacklisted */
 };
 
 static DEFINE_MUTEX(client_mutex);	/* Serialize client creation */
@@ -3926,6 +3926,7 @@ static void rbd_reregister_watch(struct work_struct *work)
 	struct rbd_device *rbd_dev = container_of(to_delayed_work(work),
 					    struct rbd_device, watch_dwork);
 	bool was_lock_owner = false;
+	bool need_to_wake = false;
 	int ret;
 
 	dout("%s rbd_dev %p\n", __func__, rbd_dev);
@@ -3935,19 +3936,27 @@ static void rbd_reregister_watch(struct work_struct *work)
 		was_lock_owner = rbd_release_lock(rbd_dev);
 
 	mutex_lock(&rbd_dev->watch_mutex);
-	if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR)
-		goto fail_unlock;
+	if (rbd_dev->watch_state != RBD_WATCH_STATE_ERROR) {
+		mutex_unlock(&rbd_dev->watch_mutex);
+		goto out;
+	}
 
 	ret = __rbd_register_watch(rbd_dev);
 	if (ret) {
 		rbd_warn(rbd_dev, "failed to reregister watch: %d", ret);
-		if (ret != -EBLACKLISTED)
+		if (ret == -EBLACKLISTED || ret == -ENOENT) {
+			set_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags);
+			need_to_wake = true;
+		} else {
 			queue_delayed_work(rbd_dev->task_wq,
 					   &rbd_dev->watch_dwork,
 					   RBD_RETRY_DELAY);
-		goto fail_unlock;
+		}
+		mutex_unlock(&rbd_dev->watch_mutex);
+		goto out;
 	}
 
+	need_to_wake = true;
 	rbd_dev->watch_state = RBD_WATCH_STATE_REGISTERED;
 	rbd_dev->watch_cookie = rbd_dev->watch_handle->linger_id;
 	mutex_unlock(&rbd_dev->watch_mutex);
@@ -3963,13 +3972,10 @@ static void rbd_reregister_watch(struct work_struct *work)
 				 ret);
 	}
 
+out:
 	up_write(&rbd_dev->lock_rwsem);
-	wake_requests(rbd_dev, true);
-	return;
-
-fail_unlock:
-	mutex_unlock(&rbd_dev->watch_mutex);
-	up_write(&rbd_dev->lock_rwsem);
+	if (need_to_wake)
+		wake_requests(rbd_dev, true);
 }
 
 /*
@@ -4074,7 +4080,9 @@ static void rbd_wait_state_locked(struct rbd_device *rbd_dev)
 		up_read(&rbd_dev->lock_rwsem);
 		schedule();
 		down_read(&rbd_dev->lock_rwsem);
-	} while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED);
+	} while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
+		 !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));
+
 	finish_wait(&rbd_dev->lock_waitq, &wait);
 }
 
@@ -4166,8 +4174,16 @@ static void rbd_queue_workfn(struct work_struct *work)
 
 	if (must_be_locked) {
 		down_read(&rbd_dev->lock_rwsem);
-		if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED)
+		if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&
+		    !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags))
 			rbd_wait_state_locked(rbd_dev);
+
+		WARN_ON((rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED) ^
+			!test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));
+		if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {
+			result = -EBLACKLISTED;
+			goto err_unlock;
+		}
 	}
 
 	img_request = rbd_img_request_create(rbd_dev, offset, length, op_type,