Commit d50ed907 authored by Christian Borntraeger's avatar Christian Borntraeger Committed by Rusty Russell
Browse files

virtio_blk: implement naming for vda-vdz,vdaa-vdzz,vdaaa-vdzzz 



Am Freitag, 1. Februar 2008 schrieb Christian Borntraeger:
> Right. I will fix that with an additional patch.

This patch goes on top of the minor number patch. Please let me know if
you want a merged patch:

Currently virtio_blk creates the disk name combinging "vd"  with 'a'++.
This will give strange names after vdz. I have implemented names up to
vdzzz - inspired by the sd.c code. That should be sufficient for now.

There is one driver in the kernel (driver/s390/block/dasd_genhd.c) that
implements names from dasda-dasdzzzz allowing even more disks. Maybe
a janitor can come up with a common implementation usable for all kind
of block device drivers.

I have tested this patch with 100 disks - seems to work.

Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 4f3bf19c

drivers/block/virtio_blk.c

+22 −7
Original line number Diff line number Diff line
@@ -9,8 +9,7 @@ 
#define VIRTIO_MAX_SG	(3+MAX_PHYS_SEGMENTS)

#define PART_BITS 4



static unsigned char virtblk_index = 'a';

static int major, minor;

static int major, index;



struct virtio_blk

{
@@ -171,6 +170,11 @@ static struct block_device_operations virtblk_fops = { 
	.getgeo = virtblk_getgeo,

};



static int index_to_minor(int index)

{

	return index << PART_BITS;

}



static int virtblk_probe(struct virtio_device *vdev)

{

	struct virtio_blk *vblk;
@@ -178,7 +182,7 @@ static int virtblk_probe(struct virtio_device *vdev) 
	u64 cap;

	u32 v;



	if (minor >= 1 << MINORBITS)

	if (index_to_minor(index) >= 1 << MINORBITS)

		return -ENOSPC;



	vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
@@ -217,13 +221,24 @@ static int virtblk_probe(struct virtio_device *vdev) 
		goto out_put_disk;

	}



	sprintf(vblk->disk->disk_name, "vd%c", virtblk_index++);

	if (index < 26) {

		sprintf(vblk->disk->disk_name, "vd%c", 'a' + index % 26);

	} else if (index < (26 + 1) * 26) {

		sprintf(vblk->disk->disk_name, "vd%c%c",

			'a' + index / 26 - 1, 'a' + index % 26);

	} else {

		const unsigned int m1 = (index / 26 - 1) / 26 - 1;

		const unsigned int m2 = (index / 26 - 1) % 26;

		const unsigned int m3 =  index % 26;

		sprintf(vblk->disk->disk_name, "vd%c%c%c",

			'a' + m1, 'a' + m2, 'a' + m3);

	}



	vblk->disk->major = major;

	vblk->disk->first_minor = minor;

	vblk->disk->first_minor = index_to_minor(index);

	vblk->disk->private_data = vblk;

	vblk->disk->fops = &virtblk_fops;



	minor += 1 << PART_BITS;

	index++;



	/* If barriers are supported, tell block layer that queue is ordered */

	if (vdev->config->feature(vdev, VIRTIO_BLK_F_BARRIER))

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