block: include empty disks in /proc/diskstats
/proc/diskstats used to show stats for all disks whether they're
zero-sized or not and their non-zero partitions. Commit
074a7aca7afa6f230104e8e65eba3420263714a5 accidentally changed the
behavior such that it doesn't print out zero sized disks. This patch
implements DISK_PITER_INCL_EMPTY_PART0 flag to partition iterator and
uses it in diskstats_show() such that empty part0 is shown in
/proc/diskstats.
Reported and bisectd by Dianel Collins.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Daniel Collins <solemnwarning@solemnwarning.no-ip.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/genhd.c b/block/genhd.c
index a9ec910..1a4916e 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -98,7 +98,7 @@
if (flags & DISK_PITER_REVERSE)
piter->idx = ptbl->len - 1;
- else if (flags & DISK_PITER_INCL_PART0)
+ else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0))
piter->idx = 0;
else
piter->idx = 1;
@@ -134,7 +134,8 @@
/* determine iteration parameters */
if (piter->flags & DISK_PITER_REVERSE) {
inc = -1;
- if (piter->flags & DISK_PITER_INCL_PART0)
+ if (piter->flags & (DISK_PITER_INCL_PART0 |
+ DISK_PITER_INCL_EMPTY_PART0))
end = -1;
else
end = 0;
@@ -150,7 +151,10 @@
part = rcu_dereference(ptbl->part[piter->idx]);
if (!part)
continue;
- if (!(piter->flags & DISK_PITER_INCL_EMPTY) && !part->nr_sects)
+ if (!part->nr_sects &&
+ !(piter->flags & DISK_PITER_INCL_EMPTY) &&
+ !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 &&
+ piter->idx == 0))
continue;
get_device(part_to_dev(part));
@@ -1011,7 +1015,7 @@
"\n\n");
*/
- disk_part_iter_init(&piter, gp, DISK_PITER_INCL_PART0);
+ disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
while ((hd = disk_part_iter_next(&piter))) {
cpu = part_stat_lock();
part_round_stats(cpu, hd);