From 71982a409f12c50d011325a4471aa20666bb908d Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 17 Apr 2009 08:34:48 +0200 Subject: [PATCH] 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 Reported-by: Daniel Collins Signed-off-by: Jens Axboe --- block/genhd.c | 12 ++++++++---- include/linux/genhd.h | 1 + 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index a9ec910974c1..1a4916e01732 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -98,7 +98,7 @@ void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk, 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 @@ struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) /* 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 @@ struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) 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 @@ static int diskstats_show(struct seq_file *seqf, void *v) "\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); diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 634c53028fb8..a1a28caed23d 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -214,6 +214,7 @@ static inline void disk_put_part(struct hd_struct *part) #define DISK_PITER_REVERSE (1 << 0) /* iterate in the reverse direction */ #define DISK_PITER_INCL_EMPTY (1 << 1) /* include 0-sized parts */ #define DISK_PITER_INCL_PART0 (1 << 2) /* include partition 0 */ +#define DISK_PITER_INCL_EMPTY_PART0 (1 << 3) /* include empty partition 0 */ struct disk_part_iter { struct gendisk *disk;