From d50ed907dc3db5bf2dd0a05b4e199a65793a3788 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Fri, 1 Feb 2008 09:05:00 +0100 Subject: [PATCH] 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 Signed-off-by: Rusty Russell --- drivers/block/virtio_blk.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 559c322c4ff..3b1a68d6edd 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -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))