block: move stats from disk to part0

Move stats related fields - stamp, in_flight, dkstats - from disk to
part0 and unify stat handling such that...

* part_stat_*() now updates part0 together if the specified partition
  is not part0.  ie. part_stat_*() are now essentially all_stat_*().

* {disk|all}_stat_*() are gone.

* part_round_stats() is updated similary.  It handles part0 stats
  automatically and disk_round_stats() is killed.

* part_{inc|dec}_in_fligh() is implemented which automatically updates
  part0 stats for parts other than part0.

* disk_map_sector_rcu() is updated to return part0 if no part matches.
  Combined with the above changes, this makes NULL special case
  handling in callers unnecessary.

* Separate stats show code paths for disk are collapsed into part
  stats show code paths.

* Rename disk_stat_lock/unlock() to part_stat_lock/unlock()

While at it, reposition stat handling macros a bit and add missing
parentheses around macro parameters.

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

1 files changed, 6 insertions, 6 deletions

diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index 60592d9f43b6..f517869e8d10 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -210,15 +210,15 @@ ssize_t part_size_show(struct device *dev,
         return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects);
 }
 
-static ssize_t part_stat_show(struct device *dev,
-                              struct device_attribute *attr, char *buf)
+ssize_t part_stat_show(struct device *dev,
+                       struct device_attribute *attr, char *buf)
 {
         struct hd_struct *p = dev_to_part(dev);
         int cpu;
 
-        cpu = disk_stat_lock();
+        cpu = part_stat_lock();
         part_round_stats(cpu, p);
-        disk_stat_unlock();
+        part_stat_unlock();
         return sprintf(buf,
                 "%8lu %8lu %8llu %8u "
                 "%8lu %8lu %8llu %8u "
@@ -575,8 +575,8 @@ void del_gendisk(struct gendisk *disk)
         set_capacity(disk, 0);
         disk->flags &= ~GENHD_FL_UP;
         unlink_gendisk(disk);
-        disk_stat_set_all(disk, 0);
-        disk->stamp = 0;
+        part_stat_set_all(&disk->part0, 0);
+        disk->part0.stamp = 0;
 
         kobject_put(disk->part0.holder_dir);
         kobject_put(disk->slave_dir);