blk-mq: do not include passthrough requests in I/O accounting

I/O accounting buckets I/O into the read/write/discard categories into
which passthrough I/O does not fit at all.  It also accounts to the
block_device, which may not even exist for passthrough I/O.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20220308055200.735835-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2022-03-08 06:51:47 +01:00 committed by Jens Axboe
parent 4e5cc99e1e
commit 41fa722239
2 changed files with 9 additions and 4 deletions

View file

@ -884,10 +884,15 @@ static inline void blk_account_io_done(struct request *req, u64 now)
static void __blk_account_io_start(struct request *rq)
{
/* passthrough requests can hold bios that do not have ->bi_bdev set */
if (rq->bio && rq->bio->bi_bdev)
/*
* All non-passthrough requests are created from a bio with one
* exception: when a flush command that is part of a flush sequence
* generated by the state machine in blk-flush.c is cloned onto the
* lower device by dm-multipath we can get here without a bio.
*/
if (rq->bio)
rq->part = rq->bio->bi_bdev;
else if (rq->q->disk)
else
rq->part = rq->q->disk->part0;
part_stat_lock();

View file

@ -325,7 +325,7 @@ int blk_dev_init(void);
*/
static inline bool blk_do_io_stat(struct request *rq)
{
return (rq->rq_flags & RQF_IO_STAT) && rq->q->disk;
return (rq->rq_flags & RQF_IO_STAT) && !blk_rq_is_passthrough(rq);
}
void update_io_ticks(struct block_device *part, unsigned long now, bool end);