On Fri, May 21, 2021 at 05:16:46PM +0000, Luis Chamberlain wrote:
- /* in consecutive minor range? */ - if (bdev->bd_partno < disk->minors) { - *devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno); - return 0; - } -It is not obviously clear to me, why this was part of add_disk() path, and ...diff --git a/block/partitions/core.c b/block/partitions/core.c index dc60ecf46fe6..504297bdc8bf 100644 --- a/block/partitions/core.c +++ b/block/partitions/core.c @@ -379,9 +380,15 @@ static struct block_device *add_partition(struct gendisk *disk, int partno, pdev->type = &part_type; pdev->parent = ddev; - err = blk_alloc_devt(bdev, &devt); - if (err) - goto out_put; + /* in consecutive minor range? */ + if (bdev->bd_partno < disk->minors) { + devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno); + } else { + err = blk_alloc_ext_minor(); + if (err < 0) + goto out_put; + devt = MKDEV(BLOCK_EXT_MAJOR, err); + } pdev->devt = devt; /* delay uevent until 'holders' subdir is created */... and why we only add this here now.
For the genhd minors == 0 (aka GENHD_FL_EXT_DEVT) implies having to allocate a dynamic dev_t, so it can be folded into another conditional.
