diff options
| -rw-r--r-- | drivers/block/xen-blkfront.c | 40 |
1 files changed, 22 insertions, 18 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 4e86393a09c..4f2b4605297 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -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)); - else - sprintf(gd->disk_name, "%s%c%c%d", DEV_NAME, - 'a' + ((offset / 26) - 1), - 'a' + (offset % 26), - 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 + snprintf(ptr, gd->disk_name + DISK_NAME_LEN - ptr, + "%d", minor & (nr_parts - 1)); gd->major = XENVBD_MAJOR; gd->first_minor = minor; |