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: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Christian Borntraeger 2008-02-01 09:05:00 +01:00 committed by Rusty Russell
parent 4f3bf19c6e
commit d50ed907dc

View file

@ -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))