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authorJerome Marchand <jmarchan@redhat.com>2009-03-27 12:31:51 +0300
committerJens Axboe <jens.axboe@oracle.com>2009-04-07 10:12:38 +0400
commit26308eab69aa193f7b3fb50764a64ae14544a39b (patch)
tree758f6100395a23228d042c3a9d6f7dc1922d7530 /block/blk-merge.c
parent6c7e8cee6a9128eeb7f83c3ad1cb243f77f5cb16 (diff)
downloadlinux-26308eab69aa193f7b3fb50764a64ae14544a39b.tar.xz
block: fix inconsistency in I/O stat accounting code
This forces in_flight to be zero when turning off or on the I/O stat accounting and stops updating I/O stats in attempt_merge() when accounting is turned off. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block/blk-merge.c')
-rw-r--r--block/blk-merge.c29
1 files changed, 17 insertions, 12 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c
index e39cb24b7679..63760ca3da0f 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -338,6 +338,22 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
return 1;
}
+static void blk_account_io_merge(struct request *req)
+{
+ if (blk_do_io_stat(req)) {
+ struct hd_struct *part;
+ int cpu;
+
+ cpu = part_stat_lock();
+ part = disk_map_sector_rcu(req->rq_disk, req->sector);
+
+ part_round_stats(cpu, part);
+ part_dec_in_flight(part);
+
+ part_stat_unlock();
+ }
+}
+
/*
* Has to be called with the request spinlock acquired
*/
@@ -386,18 +402,7 @@ static int attempt_merge(struct request_queue *q, struct request *req,
elv_merge_requests(q, req, next);
- if (req->rq_disk) {
- struct hd_struct *part;
- int cpu;
-
- cpu = part_stat_lock();
- part = disk_map_sector_rcu(req->rq_disk, req->sector);
-
- part_round_stats(cpu, part);
- part_dec_in_flight(part);
-
- part_stat_unlock();
- }
+ blk_account_io_merge(req);
req->ioprio = ioprio_best(req->ioprio, next->ioprio);
if (blk_rq_cpu_valid(next))