block: misc updates

This patch makes the following misc updates in preparation for
disk->part dereference fix and extended block devt support.

* implment part_to_disk()

* fix comment about gendisk->part indexing

* rename get_part() to disk_map_sector()

* don't use n which is always zero while printing disk information in
  diskstats_show()

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/block/genhd.c b/block/genhd.c
index 8b9a9ff1a842..11038fbc75ed 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -568,7 +568,7 @@ static int diskstats_show(struct seq_file *s, void *v)
 {
         struct gendisk *gp = v;
         char buf[BDEVNAME_SIZE];
-        int n = 0;
+        int n;
 
         /*
         if (&gp->dev.kobj.entry == block_class.devices.next)
@@ -582,7 +582,7 @@ static int diskstats_show(struct seq_file *s, void *v)
         disk_round_stats(gp);
         preempt_enable();
         seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
-                gp->major, n + gp->first_minor, disk_name(gp, n, buf),
+                gp->major, gp->first_minor, disk_name(gp, 0, buf),
                 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
                 (unsigned long long)disk_stat_read(gp, sectors[0]),
                 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),