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Commit e77c78c0 authored by Jan Beulich's avatar Jan Beulich Committed by Konrad Rzeszutek Wilk
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xen-blkfront: properly name all devices 



- devices beyond xvdzz didn't get proper names assigned at all
- extended devices with minors not representable within the kernel's
  major/minor bit split spilled into foreign majors

Signed-off-by: default avatarJan Beulich <jbeulich@suse.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent e816b57a

drivers/block/xen-blkfront.c

+22 −18
Original line number Diff line number Diff line
@@ -526,6 +526,14 @@ static int xen_translate_vdev(int vdevice, int *minor, unsigned int *offset) 
	return 0;

}



static char *encode_disk_name(char *ptr, unsigned int n)

{

	if (n >= 26)

		ptr = encode_disk_name(ptr, n / 26 - 1);

	*ptr = 'a' + n % 26;

	return ptr + 1;

}



static int xlvbd_alloc_gendisk(blkif_sector_t capacity,

			       struct blkfront_info *info,

			       u16 vdisk_info, u16 sector_size)
@@ -536,6 +544,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity, 
	unsigned int offset;

	int minor;

	int nr_parts;

	char *ptr;



	BUG_ON(info->gd != NULL);

	BUG_ON(info->rq != NULL);
@@ -560,7 +569,11 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity, 
					"emulated IDE disks,\n\t choose an xvd device name"

					"from xvde on\n", info->vdevice);

	}

	err = -ENODEV;

	if (minor >> MINORBITS) {

		pr_warn("blkfront: %#x's minor (%#x) out of range; ignoring\n",

			info->vdevice, minor);

		return -ENODEV;

	}



	if ((minor % nr_parts) == 0)

		nr_minors = nr_parts;
@@ -574,23 +587,14 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity, 
	if (gd == NULL)

		goto release;



	if (nr_minors > 1) {

		if (offset < 26)

			sprintf(gd->disk_name, "%s%c", DEV_NAME, 'a' + offset);

		else

			sprintf(gd->disk_name, "%s%c%c", DEV_NAME,

				'a' + ((offset / 26)-1), 'a' + (offset % 26));

	} else {

		if (offset < 26)

			sprintf(gd->disk_name, "%s%c%d", DEV_NAME,

				'a' + offset,

				minor & (nr_parts - 1));

	strcpy(gd->disk_name, DEV_NAME);

	ptr = encode_disk_name(gd->disk_name + sizeof(DEV_NAME) - 1, offset);

	BUG_ON(ptr >= gd->disk_name + DISK_NAME_LEN);

	if (nr_minors > 1)

		*ptr = 0;

	else

			sprintf(gd->disk_name, "%s%c%c%d", DEV_NAME,

				'a' + ((offset / 26) - 1),

				'a' + (offset % 26),

				minor & (nr_parts - 1));

	}

		snprintf(ptr, gd->disk_name + DISK_NAME_LEN - ptr,

			 "%d", minor & (nr_parts - 1));



	gd->major = XENVBD_MAJOR;

	gd->first_minor = minor;