Messages in this thread | | | Date | Thu, 14 Oct 2010 14:44:32 +0200 | From | Jens Axboe <> | Subject | Re: [PATCH] blk: fix a wrong accounting of hd_struct->in_flight |
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On 2010-10-14 08:07, KOSAKI Motohiro wrote: >> @@ -1268,7 +1270,17 @@ static int __make_request(struct request >> * not touch req->buffer either... >> */ >> req->buffer = bio_data(bio); >> + src_part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req)); >> req->__sector = bio->bi_sector; >> + dst_part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req)); > > I think this is wrong. disk_map_sector_rcu() require > rcu read lock held (see function comment). all other call site take > part_stat_lock() before disk_map_sector_rcu() call.
It's called under the queue lock with irqs disabled, which implies a rcu critical section.
-- Jens Axboe
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