2 files changed, 16 insertions, 5 deletions

diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index 0becdec12970..47189476b553 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -571,19 +571,32 @@ retry:
 	if (!node)
 		return ERR_PTR(-ENODEV);
 
+	/*
+	 * Devices that are marked unavailable are left in the cache with a
+	 * timeout to avoid sending GETDEVINFO after every LAYOUTGET, or
+	 * constantly attempting to register the device.  Once marked as
+	 * unavailable they must be deleted and never reused.
+	 */
 	if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) {
 		unsigned long end = jiffies;
 		unsigned long start = end - PNFS_DEVICE_RETRY_TIMEOUT;
 
 		if (!time_in_range(node->timestamp_unavailable, start, end)) {
+			/* Uncork subsequent GETDEVINFO operations for this device */
 			nfs4_delete_deviceid(node->ld, node->nfs_client, id);
 			goto retry;
 		}
 		goto out_put;
 	}
 
-	if (!bl_register_dev(container_of(node, struct pnfs_block_dev, node)))
+	if (!bl_register_dev(container_of(node, struct pnfs_block_dev, node))) {
+		/*
+		 * If we cannot register, treat this device as transient:
+		 * Make a negative cache entry for the device
+		 */
+		nfs4_mark_deviceid_unavailable(node);
 		goto out_put;
+	}
 
 	return node;
 
diff --git a/fs/nfs/blocklayout/dev.c b/fs/nfs/blocklayout/dev.c
index 6252f4447945..cab8809f0e0f 100644
--- a/fs/nfs/blocklayout/dev.c
+++ b/fs/nfs/blocklayout/dev.c
@@ -20,9 +20,6 @@ static void bl_unregister_scsi(struct pnfs_block_dev *dev)
 	const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 	int status;
 
-	if (!test_and_clear_bit(PNFS_BDEV_REGISTERED, &dev->flags))
-		return;
-
 	status = ops->pr_register(bdev, dev->pr_key, 0, false);
 	if (status)
 		trace_bl_pr_key_unreg_err(bdev, dev->pr_key, status);
@@ -58,7 +55,8 @@ static void bl_unregister_dev(struct pnfs_block_dev *dev)
 		return;
 	}
 
-	if (dev->type == PNFS_BLOCK_VOLUME_SCSI)
+	if (dev->type == PNFS_BLOCK_VOLUME_SCSI &&
+		test_and_clear_bit(PNFS_BDEV_REGISTERED, &dev->flags))
 		bl_unregister_scsi(dev);
 }