s390/dasd: Convert to bdev_open_by_path()

Convert dasd to use bdev_open_by_path() and pass the handle around.

CC: linux-s390@vger.kernel.org
CC: Christian Borntraeger <borntraeger@linux.ibm.com>
CC: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230927093442.25915-14-jack@suse.cz
Signed-off-by: Christian Brauner <brauner@kernel.org>

drivers/s390/block/dasd.c

@@ -412,7 +412,8 @@ dasd_state_ready_to_online(struct dasd_device * device)
 					KOBJ_CHANGE);
 			return 0;
 		}
-		disk_uevent(device->block->bdev->bd_disk, KOBJ_CHANGE);
+		disk_uevent(device->block->bdev_handle->bdev->bd_disk,
+			    KOBJ_CHANGE);
 	}
 	return 0;
 }
@@ -432,7 +433,8 @@ static int dasd_state_online_to_ready(struct dasd_device *device)
 
 	device->state = DASD_STATE_READY;
 	if (device->block && !(device->features & DASD_FEATURE_USERAW))
-		disk_uevent(device->block->bdev->bd_disk, KOBJ_CHANGE);
+		disk_uevent(device->block->bdev_handle->bdev->bd_disk,
+			    KOBJ_CHANGE);
 	return 0;
 }
 
@@ -3590,7 +3592,7 @@ int dasd_generic_set_offline(struct ccw_device *cdev)
 	 * in the other openers.
 	 */
 	if (device->block) {
-		max_count = device->block->bdev ? 0 : -1;
+		max_count = device->block->bdev_handle ? 0 : -1;
 		open_count = atomic_read(&device->block->open_count);
 		if (open_count > max_count) {
 			if (open_count > 0)
@@ -3636,8 +3638,8 @@ int dasd_generic_set_offline(struct ccw_device *cdev)
 		 * so sync bdev first and then wait for our queues to become
 		 * empty
 		 */
-		if (device->block)
-			bdev_mark_dead(device->block->bdev, false);
+		if (device->block && device->block->bdev_handle)
+			bdev_mark_dead(device->block->bdev_handle->bdev, false);
 		dasd_schedule_device_bh(device);
 		rc = wait_event_interruptible(shutdown_waitq,
 					      _wait_for_empty_queues(device));

drivers/s390/block/dasd_genhd.c

@@ -127,15 +127,15 @@ void dasd_gendisk_free(struct dasd_block *block)
  */
 int dasd_scan_partitions(struct dasd_block *block)
 {
-	struct block_device *bdev;
+	struct bdev_handle *bdev_handle;
 	int rc;
 
-	bdev = blkdev_get_by_dev(disk_devt(block->gdp), BLK_OPEN_READ, NULL,
-				 NULL);
-	if (IS_ERR(bdev)) {
+	bdev_handle = bdev_open_by_dev(disk_devt(block->gdp), BLK_OPEN_READ,
+				       NULL, NULL);
+	if (IS_ERR(bdev_handle)) {
 		DBF_DEV_EVENT(DBF_ERR, block->base,
 			      "scan partitions error, blkdev_get returned %ld",
-			      PTR_ERR(bdev));
+			      PTR_ERR(bdev_handle));
 		return -ENODEV;
 	}
 
@@ -147,16 +147,15 @@ int dasd_scan_partitions(struct dasd_block *block)
 				"scan partitions error, rc %d", rc);
 
 	/*
-	 * Since the matching blkdev_put call to the blkdev_get in
-	 * this function is not called before dasd_destroy_partitions
-	 * the offline open_count limit needs to be increased from
-	 * 0 to 1. This is done by setting device->bdev (see
-	 * dasd_generic_set_offline). As long as the partition
-	 * detection is running no offline should be allowed. That
-	 * is why the assignment to device->bdev is done AFTER
-	 * the BLKRRPART ioctl.
+	 * Since the matching bdev_release() call to the
+	 * bdev_open_by_path() in this function is not called before
+	 * dasd_destroy_partitions the offline open_count limit needs to be
+	 * increased from 0 to 1. This is done by setting device->bdev_handle
+	 * (see dasd_generic_set_offline). As long as the partition detection
+	 * is running no offline should be allowed. That is why the assignment
+	 * to block->bdev_handle is done AFTER the BLKRRPART ioctl.
 	 */
-	block->bdev = bdev;
+	block->bdev_handle = bdev_handle;
 	return 0;
 }
 
@@ -166,21 +165,21 @@ int dasd_scan_partitions(struct dasd_block *block)
  */
 void dasd_destroy_partitions(struct dasd_block *block)
 {
-	struct block_device *bdev;
+	struct bdev_handle *bdev_handle;
 
 	/*
-	 * Get the bdev pointer from the device structure and clear
-	 * device->bdev to lower the offline open_count limit again.
+	 * Get the bdev_handle pointer from the device structure and clear
+	 * device->bdev_handle to lower the offline open_count limit again.
 	 */
-	bdev = block->bdev;
-	block->bdev = NULL;
+	bdev_handle = block->bdev_handle;
+	block->bdev_handle = NULL;
 
-	mutex_lock(&bdev->bd_disk->open_mutex);
-	bdev_disk_changed(bdev->bd_disk, true);
-	mutex_unlock(&bdev->bd_disk->open_mutex);
+	mutex_lock(&bdev_handle->bdev->bd_disk->open_mutex);
+	bdev_disk_changed(bdev_handle->bdev->bd_disk, true);
+	mutex_unlock(&bdev_handle->bdev->bd_disk->open_mutex);
 
 	/* Matching blkdev_put to the blkdev_get in dasd_scan_partitions. */
-	blkdev_put(bdev, NULL);
+	bdev_release(bdev_handle);
 }
 
 int dasd_gendisk_init(void)

drivers/s390/block/dasd_int.h

@@ -650,7 +650,7 @@ struct dasd_block {
 	struct gendisk *gdp;
 	spinlock_t request_queue_lock;
 	struct blk_mq_tag_set tag_set;
-	struct block_device *bdev;
+	struct bdev_handle *bdev_handle;
 	atomic_t open_count;
 
 	unsigned long blocks;	   /* size of volume in blocks */

drivers/s390/block/dasd_ioctl.c

@@ -537,7 +537,7 @@ static int __dasd_ioctl_information(struct dasd_block *block,
 	 * This must be hidden from user-space.
 	 */
 	dasd_info->open_count = atomic_read(&block->open_count);
-	if (!block->bdev)
+	if (!block->bdev_handle)
 		dasd_info->open_count++;
 
 	/*