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authorTejun Heo <tj@kernel.org>2008-08-25 19:56:17 +0900
committerJens Axboe <jens.axboe@oracle.com>2008-10-09 08:56:08 +0200
commit3e1a7ff8a0a7b948f2684930166954f9e8e776fe (patch)
tree0a8642f5cdbc6ddfdd66dc7241c915e57b3cb7ff /block/genhd.c
parent689d6fac40b41c7bf154f362deaf442548e4dc81 (diff)
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>
Diffstat (limited to 'block/genhd.c')
-rw-r--r--block/genhd.c25
1 files changed, 24 insertions, 1 deletions
diff --git a/block/genhd.c b/block/genhd.c
index eedab5b4685..d9de3e482d1 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -478,14 +478,37 @@ static int exact_lock(dev_t devt, void *data)
*
* This function registers the partitioning information in @disk
* with the kernel.
+ *
+ * FIXME: error handling
*/
void add_disk(struct gendisk *disk)
{
struct backing_dev_info *bdi;
+ dev_t devt;
int retval;
+ /* minors == 0 indicates to use ext devt from part0 and should
+ * be accompanied with EXT_DEVT flag. Make sure all
+ * parameters make sense.
+ */
+ WARN_ON(disk->minors && !(disk->major || disk->first_minor));
+ WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT));
+
disk->flags |= GENHD_FL_UP;
- disk_to_dev(disk)->devt = MKDEV(disk->major, disk->first_minor);
+
+ retval = blk_alloc_devt(&disk->part0, &devt);
+ if (retval) {
+ WARN_ON(1);
+ return;
+ }
+ disk_to_dev(disk)->devt = devt;
+
+ /* ->major and ->first_minor aren't supposed to be
+ * dereferenced from here on, but set them just in case.
+ */
+ disk->major = MAJOR(devt);
+ disk->first_minor = MINOR(devt);
+
blk_register_region(disk_devt(disk), disk->minors, NULL,
exact_match, exact_lock, disk);
register_disk(disk);