Merge tag 'for-5.16/drivers-2021-11-09' of git://git.kernel.dk/linux-block

Pull more block driver updates from Jens Axboe:

 - Last series adding error handling support for add_disk() in drivers.
   After this one, and once the SCSI side has been merged, we can
   finally annotate add_disk() as must_check. (Luis)

 - bcache fixes (Coly)

 - zram fixes (Ming)

 - ataflop locking fix (Tetsuo)

 - nbd fixes (Ye, Yu)

 - MD merge via Song
      - Cleanup (Yang)
      - sysfs fix (Guoqing)

 - Misc fixes (Geert, Wu, luo)

* tag 'for-5.16/drivers-2021-11-09' of git://git.kernel.dk/linux-block: (34 commits)
  bcache: Revert "bcache: use bvec_virt"
  ataflop: Add missing semicolon to return statement
  floppy: address add_disk() error handling on probe
  ataflop: address add_disk() error handling on probe
  block: update __register_blkdev() probe documentation
  ataflop: remove ataflop_probe_lock mutex
  mtd/ubi/block: add error handling support for add_disk()
  block/sunvdc: add error handling support for add_disk()
  z2ram: add error handling support for add_disk()
  nvdimm/pmem: use add_disk() error handling
  nvdimm/pmem: cleanup the disk if pmem_release_disk() is yet assigned
  nvdimm/blk: add error handling support for add_disk()
  nvdimm/blk: avoid calling del_gendisk() on early failures
  nvdimm/btt: add error handling support for add_disk()
  nvdimm/btt: use goto error labels on btt_blk_init()
  loop: Remove duplicate assignments
  drbd: Fix double free problem in drbd_create_device
  nvdimm/btt: do not call del_gendisk() if not needed
  bcache: fix use-after-free problem in bcache_device_free()
  zram: replace fsync_bdev with sync_blockdev
  ...

19 files changed, 217 insertions, 100 deletions

diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index d14bdc3589b2..bf769e6e32fe 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -2008,8 +2008,6 @@ static int ataflop_alloc_disk(unsigned int drive, unsigned int type)
 	return 0;
 }
 
-static DEFINE_MUTEX(ataflop_probe_lock);
-
 static void ataflop_probe(dev_t dev)
 {
 	int drive = MINOR(dev) & 3;
@@ -2020,14 +2018,38 @@ static void ataflop_probe(dev_t dev)
 
 	if (drive >= FD_MAX_UNITS || type >= NUM_DISK_MINORS)
 		return;
-	mutex_lock(&ataflop_probe_lock);
-	if (!unit[drive].disk[type]) {
-		if (ataflop_alloc_disk(drive, type) == 0) {
-			add_disk(unit[drive].disk[type]);
-			unit[drive].registered[type] = true;
+	if (unit[drive].disk[type])
+		return;
+	if (ataflop_alloc_disk(drive, type))
+		return;
+	if (add_disk(unit[drive].disk[type]))
+		goto cleanup_disk;
+	unit[drive].registered[type] = true;
+	return;
+
+cleanup_disk:
+	blk_cleanup_disk(unit[drive].disk[type]);
+	unit[drive].disk[type] = NULL;
+}
+
+static void atari_floppy_cleanup(void)
+{
+	int i;
+	int type;
+
+	for (i = 0; i < FD_MAX_UNITS; i++) {
+		for (type = 0; type < NUM_DISK_MINORS; type++) {
+			if (!unit[i].disk[type])
+				continue;
+			del_gendisk(unit[i].disk[type]);
+			blk_cleanup_queue(unit[i].disk[type]->queue);
+			put_disk(unit[i].disk[type]);
 		}
+		blk_mq_free_tag_set(&unit[i].tag_set);
 	}
-	mutex_unlock(&ataflop_probe_lock);
+
+	del_timer_sync(&fd_timer);
+	atari_stram_free(DMABuffer);
 }
 
 static void atari_cleanup_floppy_disk(struct atari_floppy_struct *fs)
@@ -2053,11 +2075,6 @@ static int __init atari_floppy_init (void)
 		/* Amiga, Mac, ... don't have Atari-compatible floppy :-) */
 		return -ENODEV;
 
-	mutex_lock(&ataflop_probe_lock);
-	ret = __register_blkdev(FLOPPY_MAJOR, "fd", ataflop_probe);
-	if (ret)
-		goto out_unlock;
-
 	for (i = 0; i < FD_MAX_UNITS; i++) {
 		memset(&unit[i].tag_set, 0, sizeof(unit[i].tag_set));
 		unit[i].tag_set.ops = &ataflop_mq_ops;
@@ -2113,7 +2130,12 @@ static int __init atari_floppy_init (void)
 	       UseTrackbuffer ? "" : "no ");
 	config_types();
 
-	return 0;
+	ret = __register_blkdev(FLOPPY_MAJOR, "fd", ataflop_probe);
+	if (ret) {
+		printk(KERN_ERR "atari_floppy_init: cannot register block device\n");
+		atari_floppy_cleanup();
+	}
+	return ret;
 
 err_out_dma:
 	atari_stram_free(DMABuffer);
@@ -2121,9 +2143,6 @@ err:
 	while (--i >= 0)
 		atari_cleanup_floppy_disk(&unit[i]);
 
-	unregister_blkdev(FLOPPY_MAJOR, "fd");
-out_unlock:
-	mutex_unlock(&ataflop_probe_lock);
 	return ret;
 }
 
@@ -2168,14 +2187,8 @@ __setup("floppy=", atari_floppy_setup);
 
 static void __exit atari_floppy_exit(void)
 {
-	int i;
-
-	for (i = 0; i < FD_MAX_UNITS; i++)
-		atari_cleanup_floppy_disk(&unit[i]);
 	unregister_blkdev(FLOPPY_MAJOR, "fd");
-
-	del_timer_sync(&fd_timer);
-	atari_stram_free( DMABuffer );
+	atari_floppy_cleanup();
 }
 
 module_init(atari_floppy_init)
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index aa0472718dce..a896ee175d86 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -370,6 +370,7 @@ static int brd_alloc(int i)
 	struct brd_device *brd;
 	struct gendisk *disk;
 	char buf[DISK_NAME_LEN];
+	int err = -ENOMEM;
 
 	mutex_lock(&brd_devices_mutex);
 	list_for_each_entry(brd, &brd_devices, brd_list) {
@@ -420,16 +421,20 @@ static int brd_alloc(int i)
 	/* Tell the block layer that this is not a rotational device */
 	blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue);
 	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, disk->queue);
-	add_disk(disk);
+	err = add_disk(disk);
+	if (err)
+		goto out_cleanup_disk;
 
 	return 0;
 
+out_cleanup_disk:
+	blk_cleanup_disk(disk);
 out_free_dev:
 	mutex_lock(&brd_devices_mutex);
 	list_del(&brd->brd_list);
 	mutex_unlock(&brd_devices_mutex);
 	kfree(brd);
-	return -ENOMEM;
+	return err;
 }
 
 static void brd_probe(dev_t dev)
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 19db80a1e409..53ba2dddba6e 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2796,7 +2796,7 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig
 
 	err = add_disk(disk);
 	if (err)
-		goto out_cleanup_disk;
+		goto out_idr_remove_vol;
 
 	/* inherit the connection state */
 	device->state.conn = first_connection(resource)->cstate;
@@ -2810,8 +2810,6 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig
 	drbd_debugfs_device_add(device);
 	return NO_ERROR;
 
-out_cleanup_disk:
-	blk_cleanup_disk(disk);
 out_idr_remove_vol:
 	idr_remove(&connection->peer_devices, vnr);
 out_idr_remove_from_resource:
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 3873e789478e..c4267da716fe 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4528,10 +4528,19 @@ static void floppy_probe(dev_t dev)
 		return;
 
 	mutex_lock(&floppy_probe_lock);
-	if (!disks[drive][type]) {
-		if (floppy_alloc_disk(drive, type) == 0)
-			add_disk(disks[drive][type]);
-	}
+	if (disks[drive][type])
+		goto out;
+	if (floppy_alloc_disk(drive, type))
+		goto out;
+	if (add_disk(disks[drive][type]))
+		goto cleanup_disk;
+out:
+	mutex_unlock(&floppy_probe_lock);
+	return;
+
+cleanup_disk:
+	blk_cleanup_disk(disks[drive][type]);
+	disks[drive][type] = NULL;
 	mutex_unlock(&floppy_probe_lock);
 }
 
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 3c09a33fa1c7..a154cab6cd98 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1983,7 +1983,6 @@ static int loop_add(int i)
 		goto out_free_dev;
 	i = err;
 
-	err = -ENOMEM;
 	lo->tag_set.ops = &loop_mq_ops;
 	lo->tag_set.nr_hw_queues = 1;
 	lo->tag_set.queue_depth = 128;
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index b47b2a87ae8f..5a1f98494ddd 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -260,7 +260,7 @@ static void nbd_dev_remove(struct nbd_device *nbd)
 	mutex_lock(&nbd_index_mutex);
 	idr_remove(&nbd_index_idr, nbd->index);
 	mutex_unlock(&nbd_index_mutex);
-
+	destroy_workqueue(nbd->recv_workq);
 	kfree(nbd);
 }
 
@@ -755,6 +755,8 @@ static struct nbd_cmd *nbd_handle_reply(struct nbd_device *nbd, int index,
 	if (cmd->index != index) {
 		dev_err(disk_to_dev(nbd->disk), "Unexpected reply %d from different sock %d (expected %d)",
 			tag, index, cmd->index);
+		ret = -ENOENT;
+		goto out;
 	}
 	if (cmd->cmd_cookie != nbd_handle_to_cookie(handle)) {
 		dev_err(disk_to_dev(nbd->disk), "Double reply on req %p, cmd_cookie %u, handle cookie %u\n",
@@ -1314,10 +1316,6 @@ static void nbd_config_put(struct nbd_device *nbd)
 		kfree(nbd->config);
 		nbd->config = NULL;
 
-		if (nbd->recv_workq)
-			destroy_workqueue(nbd->recv_workq);
-		nbd->recv_workq = NULL;
-
 		nbd->tag_set.timeout = 0;
 		nbd->disk->queue->limits.discard_granularity = 0;
 		nbd->disk->queue->limits.discard_alignment = 0;
@@ -1346,14 +1344,6 @@ static int nbd_start_device(struct nbd_device *nbd)
 		return -EINVAL;
 	}
 
-	nbd->recv_workq = alloc_workqueue("knbd%d-recv",
-					  WQ_MEM_RECLAIM | WQ_HIGHPRI |
-					  WQ_UNBOUND, 0, nbd->index);
-	if (!nbd->recv_workq) {
-		dev_err(disk_to_dev(nbd->disk), "Could not allocate knbd recv work queue.\n");
-		return -ENOMEM;
-	}
-
 	blk_mq_update_nr_hw_queues(&nbd->tag_set, config->num_connections);
 	nbd->pid = task_pid_nr(current);
 
@@ -1779,6 +1769,15 @@ static struct nbd_device *nbd_dev_add(int index, unsigned int refs)
 	}
 	nbd->disk = disk;
 
+	nbd->recv_workq = alloc_workqueue("nbd%d-recv",
+					  WQ_MEM_RECLAIM | WQ_HIGHPRI |
+					  WQ_UNBOUND, 0, nbd->index);
+	if (!nbd->recv_workq) {
+		dev_err(disk_to_dev(nbd->disk), "Could not allocate knbd recv work queue.\n");
+		err = -ENOMEM;
+		goto out_err_disk;
+	}
+
 	/*
 	 * Tell the block layer that we are not a rotational device
 	 */
@@ -1803,13 +1802,13 @@ static struct nbd_device *nbd_dev_add(int index, unsigned int refs)
 	disk->major = NBD_MAJOR;
 
 	/* Too big first_minor can cause duplicate creation of
-	 * sysfs files/links, since first_minor will be truncated to
-	 * byte in __device_add_disk().
+	 * sysfs files/links, since index << part_shift might overflow, or
+	 * MKDEV() expect that the max bits of first_minor is 20.
 	 */
 	disk->first_minor = index << part_shift;
-	if (disk->first_minor > 0xff) {
+	if (disk->first_minor < index || disk->first_minor > MINORMASK) {
 		err = -EINVAL;
-		goto out_free_idr;
+		goto out_free_work;
 	}
 
 	disk->minors = 1 << part_shift;
@@ -1818,7 +1817,7 @@ static struct nbd_device *nbd_dev_add(int index, unsigned int refs)
 	sprintf(disk->disk_name, "nbd%d", index);
 	err = add_disk(disk);
 	if (err)
-		goto out_err_disk;
+		goto out_free_work;
 
 	/*
 	 * Now publish the device.
@@ -1827,6 +1826,8 @@ static struct nbd_device *nbd_dev_add(int index, unsigned int refs)
 	nbd_total_devices++;
 	return nbd;
 
+out_free_work:
+	destroy_workqueue(nbd->recv_workq);
 out_err_disk:
 	blk_cleanup_disk(disk);
 out_free_idr:
@@ -2082,13 +2083,10 @@ static void nbd_disconnect_and_put(struct nbd_device *nbd)
 	nbd_disconnect(nbd);
 	sock_shutdown(nbd);
 	/*
-	 * Make sure recv thread has finished, so it does not drop the last
-	 * config ref and try to destroy the workqueue from inside the work
-	 * queue. And this also ensure that we can safely call nbd_clear_que()
+	 * Make sure recv thread has finished, we can safely call nbd_clear_que()
 	 * to cancel the inflight I/Os.
 	 */
-	if (nbd->recv_workq)
-		flush_workqueue(nbd->recv_workq);
+	flush_workqueue(nbd->recv_workq);
 	nbd_clear_que(nbd);
 	nbd->task_setup = NULL;
 	mutex_unlock(&nbd->config_lock);
diff --git a/drivers/block/ps3disk.c b/drivers/block/ps3disk.c
index 8d51efbe045d..3054adf77460 100644
--- a/drivers/block/ps3disk.c
+++ b/drivers/block/ps3disk.c
@@ -467,9 +467,13 @@ static int ps3disk_probe(struct ps3_system_bus_device *_dev)
 		 gendisk->disk_name, priv->model, priv->raw_capacity >> 11,
 		 get_capacity(gendisk) >> 11);
 
-	device_add_disk(&dev->sbd.core, gendisk, NULL);
-	return 0;
+	error = device_add_disk(&dev->sbd.core, gendisk, NULL);
+	if (error)
+		goto fail_cleanup_disk;
 
+	return 0;
+fail_cleanup_disk:
+	blk_cleanup_disk(gendisk);
 fail_free_tag_set:
 	blk_mq_free_tag_set(&priv->tag_set);
 fail_teardown:
diff --git a/drivers/block/ps3vram.c b/drivers/block/ps3vram.c
index d1ebf193cb9a..c1876646a4cb 100644
--- a/drivers/block/ps3vram.c
+++ b/drivers/block/ps3vram.c
@@ -753,9 +753,14 @@ static int ps3vram_probe(struct ps3_system_bus_device *dev)
 	dev_info(&dev->core, "%s: Using %llu MiB of GPU memory\n",
 		 gendisk->disk_name, get_capacity(gendisk) >> 11);
 
-	device_add_disk(&dev->core, gendisk, NULL);
+	error = device_add_disk(&dev->core, gendisk, NULL);
+	if (error)
+		goto out_cleanup_disk;
+
 	return 0;
 
+out_cleanup_disk:
+	blk_cleanup_disk(gendisk);
 out_cache_cleanup:
 	remove_proc_entry(DEVICE_NAME, NULL);
 	ps3vram_cache_cleanup(dev);
diff --git a/drivers/block/sunvdc.c b/drivers/block/sunvdc.c
index 4d4bb810c2ae..6f45a53f7cbf 100644
--- a/drivers/block/sunvdc.c
+++ b/drivers/block/sunvdc.c
@@ -826,8 +826,8 @@ static int probe_disk(struct vdc_port *port)
 	if (IS_ERR(g)) {
 		printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
 		       port->vio.name);
-		blk_mq_free_tag_set(&port->tag_set);
-		return PTR_ERR(g);
+		err = PTR_ERR(g);
+		goto out_free_tag;
 	}
 
 	port->disk = g;
@@ -879,9 +879,17 @@ static int probe_disk(struct vdc_port *port)
 	       port->vdisk_size, (port->vdisk_size >> (20 - 9)),
 	       port->vio.ver.major, port->vio.ver.minor);
 
-	device_add_disk(&port->vio.vdev->dev, g, NULL);
+	err = device_add_disk(&port->vio.vdev->dev, g, NULL);
+	if (err)
+		goto out_cleanup_disk;
 
 	return 0;
+
+out_cleanup_disk:
+	blk_cleanup_disk(g);
+out_free_tag:
+	blk_mq_free_tag_set(&port->tag_set);
+	return err;
 }
 
 static struct ldc_channel_config vdc_ldc_cfg = {
diff --git a/drivers/block/z2ram.c b/drivers/block/z2ram.c
index 4eef218108c6..ccc52c935faf 100644
--- a/drivers/block/z2ram.c
+++ b/drivers/block/z2ram.c
@@ -318,6 +318,7 @@ static const struct blk_mq_ops z2_mq_ops = {
 static int z2ram_register_disk(int minor)
 {
 	struct gendisk *disk;
+	int err;
 
 	disk = blk_mq_alloc_disk(&tag_set, NULL);
 	if (IS_ERR(disk))
@@ -333,8 +334,10 @@ static int z2ram_register_disk(int minor)
 		sprintf(disk->disk_name, "z2ram");
 
 	z2ram_gendisk[minor] = disk;
-	add_disk(disk);
-	return 0;
+	err = add_disk(disk);
+	if (err)
+		blk_cleanup_disk(disk);
+	return err;
 }
 
 static int __init z2_init(void)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index c8931ba91b57..08d7953ec5f1 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1734,12 +1734,13 @@ static void zram_reset_device(struct zram *zram)
 	set_capacity_and_notify(zram->disk, 0);
 	part_stat_set_all(zram->disk->part0, 0);
 
-	up_write(&zram->init_lock);
 	/* I/O operation under all of CPU are done so let's free */
 	zram_meta_free(zram, disksize);
 	memset(&zram->stats, 0, sizeof(zram->stats));
 	zcomp_destroy(comp);
 	reset_bdev(zram);
+
+	up_write(&zram->init_lock);
 }
 
 static ssize_t disksize_store(struct device *dev,
@@ -1819,7 +1820,7 @@ static ssize_t reset_store(struct device *dev,
 	mutex_unlock(&bdev->bd_disk->open_mutex);
 
 	/* Make sure all the pending I/O are finished */
-	fsync_bdev(bdev);
+	sync_blockdev(bdev);
 	zram_reset_device(zram);
 
 	mutex_lock(&bdev->bd_disk->open_mutex);
@@ -1979,7 +1980,9 @@ static int zram_add(void)
 		blk_queue_max_write_zeroes_sectors(zram->disk->queue, UINT_MAX);
 
 	blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, zram->disk->queue);
-	device_add_disk(NULL, zram->disk, zram_disk_attr_groups);
+	ret = device_add_disk(NULL, zram->disk, zram_disk_attr_groups);
+	if (ret)
+		goto out_cleanup_disk;
 
 	strlcpy(zram->compressor, default_compressor, sizeof(zram->compressor));
 
@@ -1987,6 +1990,8 @@ static int zram_add(void)
 	pr_info("Added device: %s\n", zram->disk->disk_name);
 	return device_id;
 
+out_cleanup_disk:
+	blk_cleanup_disk(zram->disk);
 out_free_idr:
 	idr_remove(&zram_index_idr, device_id);
 out_free_dev:
@@ -1997,25 +2002,47 @@ out_free_dev:
 static int zram_remove(struct zram *zram)
 {
 	struct block_device *bdev = zram->disk->part0;
+	bool claimed;
 
 	mutex_lock(&bdev->bd_disk->open_mutex);
-	if (bdev->bd_openers || zram->claim) {
+	if (bdev->bd_openers) {
 		mutex_unlock(&bdev->bd_disk->open_mutex);
 		return -EBUSY;
 	}
 
-	zram->claim = true;
+	claimed = zram->claim;
+	if (!claimed)
+		zram->claim = true;
 	mutex_unlock(&bdev->bd_disk->open_mutex);
 
 	zram_debugfs_unregister(zram);
 
-	/* Make sure all the pending I/O are finished */
-	fsync_bdev(bdev);
-	zram_reset_device(zram);
+	if (claimed) {
+		/*
+		 * If we were claimed by reset_store(), del_gendisk() will
+		 * wait until reset_store() is done, so nothing need to do.
+		 */
+		;
+	} else {
+		/* Make sure all the pending I/O are finished */
+		sync_blockdev(bdev);
+		zram_reset_device(zram);
+	}
 
 	pr_info("Removed device: %s\n", zram->disk->disk_name);
 
 	del_gendisk(zram->disk);
+
+	/* del_gendisk drains pending reset_store */
+	WARN_ON_ONCE(claimed && zram->claim);
+
+	/*
+	 * disksize_store() may be called in between zram_reset_device()
+	 * and del_gendisk(), so run the last reset to avoid leaking
+	 * anything allocated with disksize_store()
+	 */
+	zram_reset_device(zram);
+
 	blk_cleanup_disk(zram->disk);
 	kfree(zram);
 	return 0;
@@ -2092,7 +2119,7 @@ static struct class zram_control_class = {
 
 static int zram_remove_cb(int id, void *ptr, void *data)
 {
-	zram_remove(ptr);
+	WARN_ON_ONCE(zram_remove(ptr));
 	return 0;
 }
 
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 93b67b8d31c3..88c573eeb598 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -378,7 +378,7 @@ static void do_btree_node_write(struct btree *b)
 		struct bvec_iter_all iter_all;
 
 		bio_for_each_segment_all(bv, b->bio, iter_all) {
-			memcpy(bvec_virt(bv), addr, PAGE_SIZE);
+			memcpy(page_address(bv->bv_page), addr, PAGE_SIZE);
 			addr += PAGE_SIZE;
 		}
 
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 4a9a65dff95e..86b9e355c583 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -885,9 +885,9 @@ static void bcache_device_free(struct bcache_device *d)
 		bcache_device_detach(d);
 
 	if (disk) {
-		blk_cleanup_disk(disk);
 		ida_simple_remove(&bcache_device_idx,
 				  first_minor_to_idx(disk->first_minor));
+		blk_cleanup_disk(disk);
 	}
 
 	bioset_exit(&d->bio_split);
diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index e29c6298ef5c..bfd6026d7809 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -2469,11 +2469,30 @@ backlog_store(struct mddev *mddev, const char *buf, size_t len)
 {
 	unsigned long backlog;
 	unsigned long old_mwb = mddev->bitmap_info.max_write_behind;
+	struct md_rdev *rdev;
+	bool has_write_mostly = false;
 	int rv = kstrtoul(buf, 10, &backlog);
 	if (rv)
 		return rv;
 	if (backlog > COUNTER_MAX)
 		return -EINVAL;
+
+	/*
+	 * Without write mostly device, it doesn't make sense to set
+	 * backlog for max_write_behind.
+	 */
+	rdev_for_each(rdev, mddev) {
+		if (test_bit(WriteMostly, &rdev->flags)) {
+			has_write_mostly = true;
+			break;
+		}
+	}
+	if (!has_write_mostly) {
+		pr_warn_ratelimited("%s: can't set backlog, no write mostly device available\n",
+				    mdname(mddev));
+		return -EINVAL;
+	}
+
 	mddev->bitmap_info.max_write_behind = backlog;
 	if (!backlog && mddev->serial_info_pool) {
 		/* serial_info_pool is not needed if backlog is zero */
diff --git a/drivers/md/raid5-ppl.c b/drivers/md/raid5-ppl.c
index 3ddc2aa0b530..4ab417915d7f 100644
--- a/drivers/md/raid5-ppl.c
+++ b/drivers/md/raid5-ppl.c
@@ -1081,7 +1081,7 @@ static int ppl_load_distributed(struct ppl_log *log)
 	struct ppl_conf *ppl_conf = log->ppl_conf;
 	struct md_rdev *rdev = log->rdev;
 	struct mddev *mddev = rdev->mddev;
-	struct page *page, *page2, *tmp;
+	struct page *page, *page2;
 	struct ppl_header *pplhdr = NULL, *prev_pplhdr = NULL;
 	u32 crc, crc_stored;
 	u32 signature;
@@ -1156,9 +1156,7 @@ static int ppl_load_distributed(struct ppl_log *log)
 		prev_pplhdr_offset = pplhdr_offset;
 		prev_pplhdr = pplhdr;
 
-		tmp = page;
-		page = page2;
-		page2 = tmp;
+		swap(page, page2);
 
 		/* calculate next potential ppl offset */
 		for (i = 0; i < le32_to_cpu(pplhdr->entries_count); i++)
diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c
index e003b4b44ffa..062e6c2c45f5 100644
--- a/drivers/mtd/ubi/block.c
+++ b/drivers/mtd/ubi/block.c
@@ -447,12 +447,18 @@ int ubiblock_create(struct ubi_volume_info *vi)
 	list_add_tail(&dev->list, &ubiblock_devices);
 
 	/* Must be the last step: anyone can call file ops from now on */
-	add_disk(dev->gd);
+	ret = add_disk(dev->gd);
+	if (ret)
+		goto out_destroy_wq;
+
 	dev_info(disk_to_dev(dev->gd), "created from ubi%d:%d(%s)",
 		 dev->ubi_num, dev->vol_id, vi->name);
 	mutex_unlock(&devices_mutex);
 	return 0;
 
+out_destroy_wq:
+	list_del(&dev->list);
+	destroy_workqueue(dev->wq);
 out_remove_minor:
 	idr_remove(&ubiblock_minor_idr, gd->first_minor);
 out_cleanup_disk:
diff --git a/drivers/nvdimm/blk.c b/drivers/nvdimm/blk.c
index b6c6866f9259..228c33b8d1d6 100644
--- a/drivers/nvdimm/blk.c
+++ b/drivers/nvdimm/blk.c
@@ -239,6 +239,7 @@ static int nsblk_attach_disk(struct nd_namespace_blk *nsblk)
 	resource_size_t available_disk_size;
 	struct gendisk *disk;
 	u64 internal_nlba;
+	int rc;
 
 	internal_nlba = div_u64(nsblk->size, nsblk_internal_lbasize(nsblk));
 	available_disk_size = internal_nlba * nsblk_sector_size(nsblk);
@@ -255,20 +256,28 @@ static int nsblk_attach_disk(struct nd_namespace_blk *nsblk)
 	blk_queue_logical_block_size(disk->queue, nsblk_sector_size(nsblk));
 	blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue);
 
-	if (devm_add_action_or_reset(dev, nd_blk_release_disk, disk))
-		return -ENOMEM;
-
 	if (nsblk_meta_size(nsblk)) {
-		int rc = nd_integrity_init(disk, nsblk_meta_size(nsblk));
+		rc = nd_integrity_init(disk, nsblk_meta_size(nsblk));
 
 		if (rc)
-			return rc;
+			goto out_before_devm_err;
 	}
 
 	set_capacity(disk, available_disk_size >> SECTOR_SHIFT);
-	device_add_disk(dev, disk, NULL);
+	rc = device_add_disk(dev, disk, NULL);
+	if (rc)
+		goto out_before_devm_err;
+
+	/* nd_blk_release_disk() is called if this fails */
+	if (devm_add_action_or_reset(dev, nd_blk_release_disk, disk))
+		return -ENOMEM;
+
 	nvdimm_check_and_set_ro(disk);
 	return 0;
+
+out_before_devm_err:
+	blk_cleanup_disk(disk);
+	return rc;
 }
 
 static int nd_blk_probe(struct device *dev)
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index f10a50ffa047..da3f007a1211 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -1519,6 +1519,7 @@ static int btt_blk_init(struct btt *btt)
 {
 	struct nd_btt *nd_btt = btt->nd_btt;
 	struct nd_namespace_common *ndns = nd_btt->ndns;
+	int rc = -ENOMEM;
 
 	btt->btt_disk = blk_alloc_disk(NUMA_NO_NODE);
 	if (!btt->btt_disk)
@@ -1534,20 +1535,24 @@ static int btt_blk_init(struct btt *btt)
 	blk_queue_flag_set(QUEUE_FLAG_NONROT, btt->btt_disk->queue);
 
 	if (btt_meta_size(btt)) {
-		int rc = nd_integrity_init(btt->btt_disk, btt_meta_size(btt));
-
-		if (rc) {
-			del_gendisk(btt->btt_disk);
-			blk_cleanup_disk(btt->btt_disk);
-			return rc;
-		}
+		rc = nd_integrity_init(btt->btt_disk, btt_meta_size(btt));
+		if (rc)
+			goto out_cleanup_disk;
 	}
+
 	set_capacity(btt->btt_disk, btt->nlba * btt->sector_size >> 9);
-	device_add_disk(&btt->nd_btt->dev, btt->btt_disk, NULL);
+	rc = device_add_disk(&btt->nd_btt->dev, btt->btt_disk, NULL);
+	if (rc)
+		goto out_cleanup_disk;
+
 	btt->nd_btt->size = btt->nlba * (u64)btt->sector_size;
 	nvdimm_check_and_set_ro(btt->btt_disk);
 
 	return 0;
+
+out_cleanup_disk:
+	blk_cleanup_disk(btt->btt_disk);
+	return rc;
 }
 
 static void btt_blk_cleanup(struct btt *btt)
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index c74d7bceb222..37fc03058556 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -428,8 +428,10 @@ static int pmem_attach_disk(struct device *dev,
 		bb_range.end = res->end;
 	}
 
-	if (IS_ERR(addr))
-		return PTR_ERR(addr);
+	if (IS_ERR(addr)) {
+		rc = PTR_ERR(addr);
+		goto out;
+	}
 	pmem->virt_addr = addr;
 
 	blk_queue_write_cache(q, true, fua);
@@ -454,12 +456,15 @@ static int pmem_attach_disk(struct device *dev,
 		flags = DAXDEV_F_SYNC;
 	dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops, flags);
 	if (IS_ERR(dax_dev)) {
-		return PTR_ERR(dax_dev);
+		rc = PTR_ERR(dax_dev);
+		goto out;
 	}
 	dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
 	pmem->dax_dev = dax_dev;
 
-	device_add_disk(dev, disk, pmem_attribute_groups);
+	rc = device_add_disk(dev, disk, pmem_attribute_groups);
+	if (rc)
+		goto out_cleanup_dax;
 	if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
 		return -ENOMEM;
 
@@ -469,8 +474,14 @@ static int pmem_attach_disk(struct device *dev,
 					  "badblocks");
 	if (!pmem->bb_state)
 		dev_warn(dev, "'badblocks' notification disabled\n");
-
 	return 0;
+
+out_cleanup_dax:
+	kill_dax(pmem->dax_dev);
+	put_dax(pmem->dax_dev);
+out:
+	blk_cleanup_disk(pmem->disk);
+	return rc;
 }
 
 static int nd_pmem_probe(struct device *dev)