xen: Implement getgeo for Xen virtual block device.

The below implements the getgeo hook for Xen block devices. Extracted
from the xen-unstable tree where it has been used for ages.

It is useful to have because it allows things like grub2 (used by the
Debian installer images) to work in a guest domain without having to
sprinkle Xen specific hacks around the place.

Signed-off-by: Ian Campbell <ijc@hellion.org.uk>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ian Campbell 2008-02-21 13:03:45 -08:00 committed by Linus Torvalds
parent 0f151e8b21
commit 597592d951

View File

@ -37,6 +37,7 @@
#include <linux/interrupt.h>
#include <linux/blkdev.h>
#include <linux/hdreg.h>
#include <linux/module.h>
#include <xen/xenbus.h>
@ -135,6 +136,22 @@ static void blkif_restart_queue_callback(void *arg)
schedule_work(&info->work);
}
int blkif_getgeo(struct block_device *bd, struct hd_geometry *hg)
{
/* We don't have real geometry info, but let's at least return
values consistent with the size of the device */
sector_t nsect = get_capacity(bd->bd_disk);
sector_t cylinders = nsect;
hg->heads = 0xff;
hg->sectors = 0x3f;
sector_div(cylinders, hg->heads * hg->sectors);
hg->cylinders = cylinders;
if ((sector_t)(hg->cylinders + 1) * hg->heads * hg->sectors < nsect)
hg->cylinders = 0xffff;
return 0;
}
/*
* blkif_queue_request
*
@ -937,6 +954,7 @@ static struct block_device_operations xlvbd_block_fops =
.owner = THIS_MODULE,
.open = blkif_open,
.release = blkif_release,
.getgeo = blkif_getgeo,
};