On 2011-04-06 03:32, Rusty Russell wrote: > On Tue, 05 Apr 2011 07:08:12 +0200, Jens Axboe <jax...@fusionio.com> wrote: >> On 2011-04-05 06:49, Takuma Umeya wrote: >>> When virtio block device is removed, index does not get decremented. When >>> another virtio disk is attached it uses the next device letter to the >>> one that is suppose to be available. >>> >>> Signed-off-by: Takuma Umeya <tum...@redhat.com> >>> >>> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c >>> index 6ecf89c..730e7af 100644 >>> --- a/drivers/block/virtio_blk.c >>> +++ b/drivers/block/virtio_blk.c >>> @@ -489,6 +489,7 @@ static void __devexit virtblk_remove(struct >>> virtio_device *vdev) >>> mempool_destroy(vblk->pool); >>> vdev->config->del_vqs(vdev); >>> kfree(vblk); >>> + index--; >>> } >>> >>> static const struct virtio_device_id id_table[] = { >> >> What happens when you delete a device that isn't the last one? > > Obviously we should do something cleverer for assigning drives. > > It might be a cute if genhd gave us a function to get the next free > index for a given major number, and format it for us, like so: > > /* Return the next available minor for a given @major, at least > * @spacing after the previous and, and append appropriate letters > * to @name if it's not NULL. -ve errno on fail (-ENOSPC?). */ > int disk_next_minor(int major, unsigned spacing, char *name); > > A trivial optimization would be to remember the last major and max minor > (resetting that if any disks are removed). > > This could clean up other code, too.
Something like idr would be a good fit for this. But yes, adding some helpers for this might not hurt... -- Jens Axboe _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linux-foundation.org/mailman/listinfo/virtualization