diff mbox series

[9/9] block: Always initialize bio IO priority on submit

Message ID 20220623074840.5960-9-jack@suse.cz (mailing list archive)
State New, archived
Headers show
Series block: Fix IO priority mess | expand

Commit Message

Jan Kara June 23, 2022, 7:48 a.m. UTC 
Currently, IO priority set in task's IO context is not reflected in the
bio->bi_ioprio for most IO (only io_uring and direct IO set it). This
results in odd results where process is submitting some bios with one
priority and other bios with a different (unset) priority and due to
differing priorities bios cannot be merged. Make sure bio->bi_ioprio is
always set on bio submission.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
 block/blk-mq.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Christoph Hellwig June 23, 2022, 2:01 p.m. UTC | #1 
On Thu, Jun 23, 2022 at 09:48:34AM +0200, Jan Kara wrote:
> Currently, IO priority set in task's IO context is not reflected in the
> bio->bi_ioprio for most IO (only io_uring and direct IO set it). This
> results in odd results where process is submitting some bios with one
> priority and other bios with a different (unset) priority and due to
> differing priorities bios cannot be merged. Make sure bio->bi_ioprio is
> always set on bio submission.

Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>
diff mbox series

Patch

diff --git a/block/blk-mq.c b/block/blk-mq.c
index e17d822e6051..7548f8aebea8 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2793,6 +2793,9 @@  static inline struct request *blk_mq_get_cached_request(struct request_queue *q,
 
 static void bio_set_ioprio(struct bio *bio)
 {
+	/* Nobody set ioprio so far? Initialize it based on task's nice value */
+	if (IOPRIO_PRIO_CLASS(bio->bi_ioprio) == IOPRIO_CLASS_NONE)
+		bio->bi_ioprio = get_current_ioprio();
 	blkcg_set_ioprio(bio);
 }