block: allow disk to have extended device number
Now that disk and partition handlings are mostly unified, it's easy to
allow disk to have extended device number. This patch makes
add_disk() use extended device number if disk->minors is zero. Both
sd and ide-disk are updated to use this.
* sd_format_disk_name() is implemented which can generically determine
the drive name. This removes disk number restriction stemming from
limited device names.
* If sd index goes over SD_MAX_DISKS (which can be increased now BTW),
sd simply doesn't initialize minors letting block layer choose
extended device number.
* If CONFIG_DEBUG_EXT_DEVT is set, both sd and ide-disk always set
minors to 0 and use extended device numbers.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 04524c2..206cdf9 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -59,6 +59,7 @@
};
#define DISK_MAX_PARTS 256
+#define DISK_NAME_LEN 32
#include <linux/major.h>
#include <linux/device.h>
@@ -140,7 +141,7 @@
int minors; /* maximum number of minors, =1 for
* disks that can't be partitioned. */
- char disk_name[32]; /* name of major driver */
+ char disk_name[DISK_NAME_LEN]; /* name of major driver */
/* Array of pointers to partitions indexed by partno.
* Protected with matching bdev lock but stat and other