Commit c97d93c3 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: factor out a part_devt helper 



Add a helper to find the dev_t for a disk + partno tuple.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210525061301.2242282-8-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ab4b5705

block/genhd.c

+17 −8
Original line number Diff line number Diff line
@@ -1227,6 +1227,19 @@ static int __init proc_genhd_init(void) 
module_init(proc_genhd_init);

#endif /* CONFIG_PROC_FS */



dev_t part_devt(struct gendisk *disk, u8 partno)

{

	struct block_device *part = bdget_disk(disk, partno);

	dev_t devt = 0;



	if (part) {

		devt = part->bd_dev;

		bdput(part);

	}



	return devt;

}



dev_t blk_lookup_devt(const char *name, int partno)

{

	dev_t devt = MKDEV(0, 0);
@@ -1236,7 +1249,6 @@ dev_t blk_lookup_devt(const char *name, int partno) 
	class_dev_iter_init(&iter, &block_class, NULL, &disk_type);

	while ((dev = class_dev_iter_next(&iter))) {

		struct gendisk *disk = dev_to_disk(dev);

		struct block_device *part;



		if (strcmp(dev_name(dev), name))

			continue;
@@ -1247,12 +1259,9 @@ dev_t blk_lookup_devt(const char *name, int partno) 
			 */

			devt = MKDEV(MAJOR(dev->devt),

				     MINOR(dev->devt) + partno);

			break;

		}

		part = bdget_disk(disk, partno);

		if (part) {

			devt = part->bd_dev;

			bdput(part);

		} else {

			devt = part_devt(disk, partno);

			if (devt)

				break;

		}

	}

include/linux/genhd.h

+1 −0
Original line number Diff line number Diff line
@@ -333,6 +333,7 @@ static inline void bd_unlink_disk_holder(struct block_device *bdev, 
}

#endif /* CONFIG_SYSFS */



dev_t part_devt(struct gendisk *disk, u8 partno);

dev_t blk_lookup_devt(const char *name, int partno);

void blk_request_module(dev_t devt);

#ifdef CONFIG_BLOCK

init/do_mounts.c

+2 −8
Original line number Diff line number Diff line
@@ -133,14 +133,8 @@ static dev_t devt_from_partuuid(const char *uuid_str) 
		 * Attempt to find the requested partition by adding an offset

		 * to the partition number found by UUID.

		 */

		struct block_device *part;



		part = bdget_disk(dev_to_disk(dev),

		devt = part_devt(dev_to_disk(dev),

				 dev_to_bdev(dev)->bd_partno + offset);

		if (part) {

			devt = part->bd_dev;

			bdput(part);

		}

	} else {

		devt = dev->devt;

	}