block: factor out a part_devt helper

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

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210525061301.2242282-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2021-05-25 08:13:00 +02:00 committed by Jens Axboe
parent ab4b57057d
commit c97d93c31e
3 changed files with 20 additions and 16 deletions

View File

@ -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;
@ -1247,13 +1259,10 @@ 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);
break;
} else {
devt = part_devt(disk, partno);
if (devt)
break;
}
}
class_dev_iter_exit(&iter);

View File

@ -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

View File

@ -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),
dev_to_bdev(dev)->bd_partno + offset);
if (part) {
devt = part->bd_dev;
bdput(part);
}
devt = part_devt(dev_to_disk(dev),
dev_to_bdev(dev)->bd_partno + offset);
} else {
devt = dev->devt;
}