Merge tag 'block-5.14-2021-07-08' of git://git.kernel.dk/linux-block

Pull more block updates from Jens Axboe:
 "A combination of changes that ended up depending on both the driver
  and core branch (and/or the IDE removal), and a few late arriving
  fixes. In detail:

   - Fix io ticks wrap-around issue (Chunguang)

   - nvme-tcp sock locking fix (Maurizio)

   - s390-dasd fixes (Kees, Christoph)

   - blk_execute_rq polling support (Keith)

   - blk-cgroup RCU iteration fix (Yu)

   - nbd backend ID addition (Prasanna)

   - Partition deletion fix (Yufen)

   - Use blk_mq_alloc_disk for mmc, mtip32xx, ubd (Christoph)

   - Removal of now dead block request types due to IDE removal
     (Christoph)

   - Loop probing and control device cleanups (Christoph)

   - Device uevent fix (Christoph)

   - Misc cleanups/fixes (Tetsuo, Christoph)"

* tag 'block-5.14-2021-07-08' of git://git.kernel.dk/linux-block: (34 commits)
  blk-cgroup: prevent rcu_sched detected stalls warnings while iterating blkgs
  block: fix the problem of io_ticks becoming smaller
  nvme-tcp: can't set sk_user_data without write_lock
  loop: remove unused variable in loop_set_status()
  block: remove the bdgrab in blk_drop_partitions
  block: grab a device refcount in disk_uevent
  s390/dasd: Avoid field over-reading memcpy()
  dasd: unexport dasd_set_target_state
  block: check disk exist before trying to add partition
  ubd: remove dead code in ubd_setup_common
  nvme: use return value from blk_execute_rq()
  block: return errors from blk_execute_rq()
  nvme: use blk_execute_rq() for passthrough commands
  block: support polling through blk_execute_rq
  block: remove REQ_OP_SCSI_{IN,OUT}
  block: mark blk_mq_init_queue_data static
  loop: rewrite loop_exit using idr_for_each_entry
  loop: split loop_lookup
  loop: don't allow deleting an unspecified loop device
  loop: move loop_ctl_mutex locking into loop_add
  ...

5 files changed, 172 insertions, 210 deletions

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index cc0e8c39a48b..f37b9e3d833c 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1434,7 +1434,6 @@ static int
 loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
 {
 	int err;
-	struct block_device *bdev;
 	kuid_t uid = current_uid();
 	int prev_lo_flags;
 	bool partscan = false;
@@ -1503,7 +1502,6 @@ out_unfreeze:
 	if (!err && (lo->lo_flags & LO_FLAGS_PARTSCAN) &&
 	     !(prev_lo_flags & LO_FLAGS_PARTSCAN)) {
 		lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN;
-		bdev = lo->lo_device;
 		partscan = true;
 	}
 out_unlock:
@@ -2237,7 +2235,7 @@ static const struct blk_mq_ops loop_mq_ops = {
 	.complete	= lo_complete_rq,
 };
 
-static int loop_add(struct loop_device **l, int i)
+static int loop_add(int i)
 {
 	struct loop_device *lo;
 	struct gendisk *disk;
@@ -2247,9 +2245,12 @@ static int loop_add(struct loop_device **l, int i)
 	lo = kzalloc(sizeof(*lo), GFP_KERNEL);
 	if (!lo)
 		goto out;
-
 	lo->lo_state = Lo_unbound;
 
+	err = mutex_lock_killable(&loop_ctl_mutex);
+	if (err)
+		goto out_free_dev;
+
 	/* allocate id, if @id >= 0, we're requesting that specific id */
 	if (i >= 0) {
 		err = idr_alloc(&loop_index_idr, lo, i, i + 1, GFP_KERNEL);
@@ -2259,7 +2260,7 @@ static int loop_add(struct loop_device **l, int i)
 		err = idr_alloc(&loop_index_idr, lo, 0, 0, GFP_KERNEL);
 	}
 	if (err < 0)
-		goto out_free_dev;
+		goto out_unlock;
 	i = err;
 
 	err = -ENOMEM;
@@ -2326,13 +2327,15 @@ static int loop_add(struct loop_device **l, int i)
 	disk->queue		= lo->lo_queue;
 	sprintf(disk->disk_name, "loop%d", i);
 	add_disk(disk);
-	*l = lo;
-	return lo->lo_number;
+	mutex_unlock(&loop_ctl_mutex);
+	return i;
 
 out_cleanup_tags:
 	blk_mq_free_tag_set(&lo->tag_set);
 out_free_idr:
 	idr_remove(&loop_index_idr, i);
+out_unlock:
+	mutex_unlock(&loop_ctl_mutex);
 out_free_dev:
 	kfree(lo);
 out:
@@ -2348,109 +2351,86 @@ static void loop_remove(struct loop_device *lo)
 	kfree(lo);
 }
 
-static int find_free_cb(int id, void *ptr, void *data)
+static void loop_probe(dev_t dev)
 {
-	struct loop_device *lo = ptr;
-	struct loop_device **l = data;
+	int idx = MINOR(dev) >> part_shift;
 
-	if (lo->lo_state == Lo_unbound) {
-		*l = lo;
-		return 1;
-	}
-	return 0;
+	if (max_loop && idx >= max_loop)
+		return;
+	loop_add(idx);
 }
 
-static int loop_lookup(struct loop_device **l, int i)
+static int loop_control_remove(int idx)
 {
 	struct loop_device *lo;
-	int ret = -ENODEV;
+	int ret;
 
-	if (i < 0) {
-		int err;
+	if (idx < 0) {
+		pr_warn("deleting an unspecified loop device is not supported.\n");
+		return -EINVAL;
+	}
+		
+	ret = mutex_lock_killable(&loop_ctl_mutex);
+	if (ret)
+		return ret;
 
-		err = idr_for_each(&loop_index_idr, &find_free_cb, &lo);
-		if (err == 1) {
-			*l = lo;
-			ret = lo->lo_number;
-		}
-		goto out;
+	lo = idr_find(&loop_index_idr, idx);
+	if (!lo) {
+		ret = -ENODEV;
+		goto out_unlock_ctrl;
 	}
 
-	/* lookup and return a specific i */
-	lo = idr_find(&loop_index_idr, i);
-	if (lo) {
-		*l = lo;
-		ret = lo->lo_number;
+	ret = mutex_lock_killable(&lo->lo_mutex);
+	if (ret)
+		goto out_unlock_ctrl;
+	if (lo->lo_state != Lo_unbound ||
+	    atomic_read(&lo->lo_refcnt) > 0) {
+		mutex_unlock(&lo->lo_mutex);
+		ret = -EBUSY;
+		goto out_unlock_ctrl;
 	}
-out:
+	lo->lo_state = Lo_deleting;
+	mutex_unlock(&lo->lo_mutex);
+
+	idr_remove(&loop_index_idr, lo->lo_number);
+	loop_remove(lo);
+out_unlock_ctrl:
+	mutex_unlock(&loop_ctl_mutex);
 	return ret;
 }
 
-static void loop_probe(dev_t dev)
+static int loop_control_get_free(int idx)
 {
-	int idx = MINOR(dev) >> part_shift;
 	struct loop_device *lo;
+	int id, ret;
 
-	if (max_loop && idx >= max_loop)
-		return;
-
-	mutex_lock(&loop_ctl_mutex);
-	if (loop_lookup(&lo, idx) < 0)
-		loop_add(&lo, idx);
+	ret = mutex_lock_killable(&loop_ctl_mutex);
+	if (ret)
+		return ret;
+	idr_for_each_entry(&loop_index_idr, lo, id) {
+		if (lo->lo_state == Lo_unbound)
+			goto found;
+	}
 	mutex_unlock(&loop_ctl_mutex);
+	return loop_add(-1);
+found:
+	mutex_unlock(&loop_ctl_mutex);
+	return id;
 }
 
 static long loop_control_ioctl(struct file *file, unsigned int cmd,
 			       unsigned long parm)
 {
-	struct loop_device *lo;
-	int ret;
-
-	ret = mutex_lock_killable(&loop_ctl_mutex);
-	if (ret)
-		return ret;
-
-	ret = -ENOSYS;
 	switch (cmd) {
 	case LOOP_CTL_ADD:
-		ret = loop_lookup(&lo, parm);
-		if (ret >= 0) {
-			ret = -EEXIST;
-			break;
-		}
-		ret = loop_add(&lo, parm);
-		break;
+		return loop_add(parm);
 	case LOOP_CTL_REMOVE:
-		ret = loop_lookup(&lo, parm);
-		if (ret < 0)
-			break;
-		ret = mutex_lock_killable(&lo->lo_mutex);
-		if (ret)
-			break;
-		if (lo->lo_state != Lo_unbound) {
-			ret = -EBUSY;
-			mutex_unlock(&lo->lo_mutex);
-			break;
-		}
-		if (atomic_read(&lo->lo_refcnt) > 0) {
-			ret = -EBUSY;
-			mutex_unlock(&lo->lo_mutex);
-			break;
-		}
-		lo->lo_state = Lo_deleting;
-		mutex_unlock(&lo->lo_mutex);
-		idr_remove(&loop_index_idr, lo->lo_number);
-		loop_remove(lo);
-		break;
+		return loop_control_remove(parm);
 	case LOOP_CTL_GET_FREE:
-		ret = loop_lookup(&lo, -1);
-		if (ret >= 0)
-			break;
-		ret = loop_add(&lo, -1);
+		return loop_control_get_free(parm);
+	default:
+		return -ENOSYS;
 	}
-	mutex_unlock(&loop_ctl_mutex);
-
-	return ret;
 }
 
 static const struct file_operations loop_ctl_fops = {
@@ -2473,7 +2453,6 @@ MODULE_ALIAS("devname:loop-control");
 static int __init loop_init(void)
 {
 	int i, nr;
-	struct loop_device *lo;
 	int err;
 
 	part_shift = 0;
@@ -2525,10 +2504,8 @@ static int __init loop_init(void)
 	}
 
 	/* pre-create number of devices given by config or max_loop */
-	mutex_lock(&loop_ctl_mutex);
 	for (i = 0; i < nr; i++)
-		loop_add(&lo, i);
-	mutex_unlock(&loop_ctl_mutex);
+		loop_add(i);
 
 	printk(KERN_INFO "loop: module loaded\n");
 	return 0;
@@ -2539,26 +2516,20 @@ err_out:
 	return err;
 }
 
-static int loop_exit_cb(int id, void *ptr, void *data)
-{
-	struct loop_device *lo = ptr;
-
-	loop_remove(lo);
-	return 0;
-}
-
 static void __exit loop_exit(void)
 {
-	mutex_lock(&loop_ctl_mutex);
-
-	idr_for_each(&loop_index_idr, &loop_exit_cb, NULL);
-	idr_destroy(&loop_index_idr);
+	struct loop_device *lo;
+	int id;
 
 	unregister_blkdev(LOOP_MAJOR, "loop");
-
 	misc_deregister(&loop_misc);
 
+	mutex_lock(&loop_ctl_mutex);
+	idr_for_each_entry(&loop_index_idr, lo, id)
+		loop_remove(lo);
 	mutex_unlock(&loop_ctl_mutex);
+
+	idr_destroy(&loop_index_idr);
 }
 
 module_init(loop_init);
diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index ff3e7b3f5ad8..901855717cb5 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -2160,6 +2160,20 @@ static ssize_t mtip_hw_show_status(struct device *dev,
 
 static DEVICE_ATTR(status, 0444, mtip_hw_show_status, NULL);
 
+static struct attribute *mtip_disk_attrs[] = {
+	&dev_attr_status.attr,
+	NULL,
+};
+
+static const struct attribute_group mtip_disk_attr_group = {
+	.attrs = mtip_disk_attrs,
+};
+
+static const struct attribute_group *mtip_disk_attr_groups[] = {
+	&mtip_disk_attr_group,
+	NULL,
+};
+
 /* debugsfs entries */
 
 static ssize_t show_device_status(struct device_driver *drv, char *buf)
@@ -2374,47 +2388,6 @@ static const struct file_operations mtip_flags_fops = {
 	.llseek = no_llseek,
 };
 
-/*
- * Create the sysfs related attributes.
- *
- * @dd   Pointer to the driver data structure.
- * @kobj Pointer to the kobj for the block device.
- *
- * return value
- *	0	Operation completed successfully.
- *	-EINVAL Invalid parameter.
- */
-static int mtip_hw_sysfs_init(struct driver_data *dd, struct kobject *kobj)
-{
-	if (!kobj || !dd)
-		return -EINVAL;
-
-	if (sysfs_create_file(kobj, &dev_attr_status.attr))
-		dev_warn(&dd->pdev->dev,
-			"Error creating 'status' sysfs entry\n");
-	return 0;
-}
-
-/*
- * Remove the sysfs related attributes.
- *
- * @dd   Pointer to the driver data structure.
- * @kobj Pointer to the kobj for the block device.
- *
- * return value
- *	0	Operation completed successfully.
- *	-EINVAL Invalid parameter.
- */
-static int mtip_hw_sysfs_exit(struct driver_data *dd, struct kobject *kobj)
-{
-	if (!kobj || !dd)
-		return -EINVAL;
-
-	sysfs_remove_file(kobj, &dev_attr_status.attr);
-
-	return 0;
-}
-
 static int mtip_hw_debugfs_init(struct driver_data *dd)
 {
 	if (!dfs_parent)
@@ -3566,7 +3539,6 @@ static int mtip_block_initialize(struct driver_data *dd)
 	int rv = 0, wait_for_rebuild = 0;
 	sector_t capacity;
 	unsigned int index = 0;
-	struct kobject *kobj;
 
 	if (dd->disk)
 		goto skip_create_disk; /* hw init done, before rebuild */
@@ -3576,35 +3548,6 @@ static int mtip_block_initialize(struct driver_data *dd)
 		goto protocol_init_error;
 	}
 
-	dd->disk = alloc_disk_node(MTIP_MAX_MINORS, dd->numa_node);
-	if (dd->disk  == NULL) {
-		dev_err(&dd->pdev->dev,
-			"Unable to allocate gendisk structure\n");
-		rv = -EINVAL;
-		goto alloc_disk_error;
-	}
-
-	rv = ida_alloc(&rssd_index_ida, GFP_KERNEL);
-	if (rv < 0)
-		goto ida_get_error;
-	index = rv;
-
-	rv = rssd_disk_name_format("rssd",
-				index,
-				dd->disk->disk_name,
-				DISK_NAME_LEN);
-	if (rv)
-		goto disk_index_error;
-
-	dd->disk->major		= dd->major;
-	dd->disk->first_minor	= index * MTIP_MAX_MINORS;
-	dd->disk->minors 	= MTIP_MAX_MINORS;
-	dd->disk->fops		= &mtip_block_ops;
-	dd->disk->private_data	= dd;
-	dd->index		= index;
-
-	mtip_hw_debugfs_init(dd);
-
 	memset(&dd->tags, 0, sizeof(dd->tags));
 	dd->tags.ops = &mtip_mq_ops;
 	dd->tags.nr_hw_queues = 1;
@@ -3623,17 +3566,35 @@ static int mtip_block_initialize(struct driver_data *dd)
 		goto block_queue_alloc_tag_error;
 	}
 
-	/* Allocate the request queue. */
-	dd->queue = blk_mq_init_queue(&dd->tags);
-	if (IS_ERR(dd->queue)) {
+	dd->disk = blk_mq_alloc_disk(&dd->tags, dd);
+	if (IS_ERR(dd->disk)) {
 		dev_err(&dd->pdev->dev,
 			"Unable to allocate request queue\n");
 		rv = -ENOMEM;
 		goto block_queue_alloc_init_error;
 	}
+	dd->queue		= dd->disk->queue;
+
+	rv = ida_alloc(&rssd_index_ida, GFP_KERNEL);
+	if (rv < 0)
+		goto ida_get_error;
+	index = rv;
+
+	rv = rssd_disk_name_format("rssd",
+				index,
+				dd->disk->disk_name,
+				DISK_NAME_LEN);
+	if (rv)
+		goto disk_index_error;
+
+	dd->disk->major		= dd->major;
+	dd->disk->first_minor	= index * MTIP_MAX_MINORS;
+	dd->disk->minors 	= MTIP_MAX_MINORS;
+	dd->disk->fops		= &mtip_block_ops;
+	dd->disk->private_data	= dd;
+	dd->index		= index;
 
-	dd->disk->queue		= dd->queue;
-	dd->queue->queuedata	= dd;
+	mtip_hw_debugfs_init(dd);
 
 skip_create_disk:
 	/* Initialize the protocol layer. */
@@ -3672,17 +3633,7 @@ skip_create_disk:
 	set_capacity(dd->disk, capacity);
 
 	/* Enable the block device and add it to /dev */
-	device_add_disk(&dd->pdev->dev, dd->disk, NULL);
-
-	/*
-	 * Now that the disk is active, initialize any sysfs attributes
-	 * managed by the protocol layer.
-	 */
-	kobj = kobject_get(&disk_to_dev(dd->disk)->kobj);
-	if (kobj) {
-		mtip_hw_sysfs_init(dd, kobj);
-		kobject_put(kobj);
-	}
+	device_add_disk(&dd->pdev->dev, dd->disk, mtip_disk_attr_groups);
 
 	if (dd->mtip_svc_handler) {
 		set_bit(MTIP_DDF_INIT_DONE_BIT, &dd->dd_flag);
@@ -3709,23 +3660,17 @@ start_service_thread:
 kthread_run_error:
 	/* Delete our gendisk. This also removes the device from /dev */
 	del_gendisk(dd->disk);
-
 read_capacity_error:
 init_hw_cmds_error:
-	blk_cleanup_queue(dd->queue);
-block_queue_alloc_init_error:
-	blk_mq_free_tag_set(&dd->tags);
-block_queue_alloc_tag_error:
 	mtip_hw_debugfs_exit(dd);
 disk_index_error:
 	ida_free(&rssd_index_ida, index);
-
 ida_get_error:
-	put_disk(dd->disk);
-
-alloc_disk_error:
+	blk_cleanup_disk(dd->disk);
+block_queue_alloc_init_error:
+	blk_mq_free_tag_set(&dd->tags);
+block_queue_alloc_tag_error:
 	mtip_hw_exit(dd); /* De-initialize the protocol layer. */
-
 protocol_init_error:
 	return rv;
 }
@@ -3751,8 +3696,6 @@ static bool mtip_no_dev_cleanup(struct request *rq, void *data, bool reserv)
  */
 static int mtip_block_remove(struct driver_data *dd)
 {
-	struct kobject *kobj;
-
 	mtip_hw_debugfs_exit(dd);
 
 	if (dd->mtip_svc_handler) {
@@ -3761,15 +3704,6 @@ static int mtip_block_remove(struct driver_data *dd)
 		kthread_stop(dd->mtip_svc_handler);
 	}
 
-	/* Clean up the sysfs attributes, if created */
-	if (test_bit(MTIP_DDF_INIT_DONE_BIT, &dd->dd_flag)) {
-		kobj = kobject_get(&disk_to_dev(dd->disk)->kobj);
-		if (kobj) {
-			mtip_hw_sysfs_exit(dd, kobj);
-			kobject_put(kobj);
-		}
-	}
-
 	if (!dd->sr) {
 		/*
 		 * Explicitly wait here for IOs to quiesce,
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 614d82e7fae4..b7d663736d35 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -79,6 +79,7 @@ struct link_dead_args {
 #define NBD_RT_HAS_CONFIG_REF		4
 #define NBD_RT_BOUND			5
 #define NBD_RT_DISCONNECT_ON_CLOSE	6
+#define NBD_RT_HAS_BACKEND_FILE		7
 
 #define NBD_DESTROY_ON_DISCONNECT	0
 #define NBD_DISCONNECT_REQUESTED	1
@@ -119,6 +120,8 @@ struct nbd_device {
 
 	struct completion *destroy_complete;
 	unsigned long flags;
+
+	char *backend;
 };
 
 #define NBD_CMD_REQUEUED	1
@@ -216,6 +219,20 @@ static const struct device_attribute pid_attr = {
 	.show = pid_show,
 };
 
+static ssize_t backend_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct gendisk *disk = dev_to_disk(dev);
+	struct nbd_device *nbd = (struct nbd_device *)disk->private_data;
+
+	return sprintf(buf, "%s\n", nbd->backend ?: "");
+}
+
+static const struct device_attribute backend_attr = {
+	.attr = { .name = "backend", .mode = 0444},
+	.show = backend_show,
+};
+
 static void nbd_dev_remove(struct nbd_device *nbd)
 {
 	struct gendisk *disk = nbd->disk;
@@ -1211,6 +1228,12 @@ static void nbd_config_put(struct nbd_device *nbd)
 				       &config->runtime_flags))
 			device_remove_file(disk_to_dev(nbd->disk), &pid_attr);
 		nbd->task_recv = NULL;
+		if (test_and_clear_bit(NBD_RT_HAS_BACKEND_FILE,
+				       &config->runtime_flags)) {
+			device_remove_file(disk_to_dev(nbd->disk), &backend_attr);
+			kfree(nbd->backend);
+			nbd->backend = NULL;
+		}
 		nbd_clear_sock(nbd);
 		if (config->num_connections) {
 			int i;
@@ -1270,7 +1293,7 @@ static int nbd_start_device(struct nbd_device *nbd)
 
 	error = device_create_file(disk_to_dev(nbd->disk), &pid_attr);
 	if (error) {
-		dev_err(disk_to_dev(nbd->disk), "device_create_file failed!\n");
+		dev_err(disk_to_dev(nbd->disk), "device_create_file failed for pid!\n");
 		return error;
 	}
 	set_bit(NBD_RT_HAS_PID_FILE, &config->runtime_flags);
@@ -1657,6 +1680,7 @@ static int nbd_dev_add(int index)
 		BLK_MQ_F_BLOCKING;
 	nbd->tag_set.driver_data = nbd;
 	nbd->destroy_complete = NULL;
+	nbd->backend = NULL;
 
 	err = blk_mq_alloc_tag_set(&nbd->tag_set);
 	if (err)
@@ -1743,6 +1767,7 @@ static const struct nla_policy nbd_attr_policy[NBD_ATTR_MAX + 1] = {
 	[NBD_ATTR_SOCKETS]		=	{ .type = NLA_NESTED},
 	[NBD_ATTR_DEAD_CONN_TIMEOUT]	=	{ .type = NLA_U64 },
 	[NBD_ATTR_DEVICE_LIST]		=	{ .type = NLA_NESTED},
+	[NBD_ATTR_BACKEND_IDENTIFIER]	=	{ .type = NLA_STRING},
 };
 
 static const struct nla_policy nbd_sock_policy[NBD_SOCK_MAX + 1] = {
@@ -1945,6 +1970,23 @@ again:
 		}
 	}
 	ret = nbd_start_device(nbd);
+	if (ret)
+		goto out;
+	if (info->attrs[NBD_ATTR_BACKEND_IDENTIFIER]) {
+		nbd->backend = nla_strdup(info->attrs[NBD_ATTR_BACKEND_IDENTIFIER],
+					  GFP_KERNEL);
+		if (!nbd->backend) {
+			ret = -ENOMEM;
+			goto out;
+		}
+	}
+	ret = device_create_file(disk_to_dev(nbd->disk), &backend_attr);
+	if (ret) {
+		dev_err(disk_to_dev(nbd->disk),
+			"device_create_file failed for backend!\n");
+		goto out;
+	}
+	set_bit(NBD_RT_HAS_BACKEND_FILE, &config->runtime_flags);
 out:
 	mutex_unlock(&nbd->config_lock);
 	if (!ret) {
@@ -2037,6 +2079,22 @@ static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info)
 		       index);
 		return -EINVAL;
 	}
+	if (nbd->backend) {
+		if (info->attrs[NBD_ATTR_BACKEND_IDENTIFIER]) {
+			if (nla_strcmp(info->attrs[NBD_ATTR_BACKEND_IDENTIFIER],
+				       nbd->backend)) {
+				mutex_unlock(&nbd_index_mutex);
+				dev_err(nbd_to_dev(nbd),
+					"backend image doesn't match with %s\n",
+					nbd->backend);
+				return -EINVAL;
+			}
+		} else {
+			mutex_unlock(&nbd_index_mutex);
+			dev_err(nbd_to_dev(nbd), "must specify backend\n");
+			return -EINVAL;
+		}
+	}
 	if (!refcount_inc_not_zero(&nbd->refs)) {
 		mutex_unlock(&nbd_index_mutex);
 		printk(KERN_ERR "nbd: device at index %d is going down\n",
diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 3b320b005aa8..d734e9ee1546 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -1849,7 +1849,6 @@ static int null_add_dev(struct nullb_device *dev)
 		if (!null_setup_fault())
 			goto out_cleanup_tags;
 
-		rv = -ENOMEM;
 		nullb->tag_set->timeout = 5 * HZ;
 		nullb->disk = blk_mq_alloc_disk(nullb->tag_set, nullb);
 		if (IS_ERR(nullb->disk)) {
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index f69b5c69c2a6..538446b652de 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -704,7 +704,7 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *
 	int ret = 0;
 
 	rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
-			     REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
+			     REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
 	if (IS_ERR(rq))
 		return PTR_ERR(rq);