From: Damien Le Moal <damien.lemoal@opensource.wdc.com>
To: Pankaj Raghav <p.raghav@samsung.com>,
linux-block@vger.kernel.org, axboe@kernel.dk
Cc: gost.dev@samsung.com
Subject: Re: [PATCH 1/2] block: modify blk_mq_plug() to allow only reads for zoned block devices
Date: Mon, 26 Sep 2022 07:55:13 +0900 [thread overview]
Message-ID: <736c593b-a8cb-0e68-c895-cb89bc29b68e@opensource.wdc.com> (raw)
In-Reply-To: <20220925185348.120964-2-p.raghav@samsung.com>
On 9/26/22 03:53, Pankaj Raghav wrote:
> Modify blk_mq_plug() to allow plugging only for read operations in zoned
> block devices as there are alternative IO paths in the linux block
> layer which can end up doing a write via driver private requests in
> sequential write zones.
>
> Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
> ---
> block/blk-mq.h | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/block/blk-mq.h b/block/blk-mq.h
> index 8ca453ac243d..005343df64ca 100644
> --- a/block/blk-mq.h
> +++ b/block/blk-mq.h
> @@ -305,14 +305,15 @@ static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
> * change can cause write BIO failures with zoned block devices as these
> * require sequential write patterns to zones. Prevent this from happening by
> * ignoring the plug state of a BIO issuing context if it is for a zoned block
> - * device and the BIO to plug is a write operation.
> + * device and the BIO to plug is not a read operation.
> + *
> *
> * Return current->plug if the bio can be plugged and NULL otherwise
> */
> static inline struct blk_plug *blk_mq_plug( struct bio *bio)
> {
> - /* Zoned block device write operation case: do not plug the BIO */
> - if (bdev_is_zoned(bio->bi_bdev) && op_is_write(bio_op(bio)))
> + /* Allow plugging only for read operations in zoned block devices */
nit: s/in/with
> + if (bdev_is_zoned(bio->bi_bdev) && bio_op(bio) != REQ_OP_READ)
> return NULL;
>
> /*
Otherwise, looks good to me.
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
--
Damien Le Moal
Western Digital Research
next prev parent reply other threads:[~2022-09-25 22:55 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20220925185349eucas1p1dc689bac64668ca038ba8646c44fd580@eucas1p1.samsung.com>
2022-09-25 18:53 ` [PATCH 0/2] enable plugging only for reads in zoned block devices Pankaj Raghav
[not found] ` <CGME20220925185350eucas1p1fc354429027a88de7e548a3a4529b4ef@eucas1p1.samsung.com>
2022-09-25 18:53 ` [PATCH 1/2] block: modify blk_mq_plug() to allow only reads for " Pankaj Raghav
2022-09-25 22:55 ` Damien Le Moal [this message]
2022-09-26 14:37 ` Christoph Hellwig
2022-09-26 14:40 ` Jens Axboe
2022-09-26 14:43 ` Christoph Hellwig
2022-09-26 16:32 ` Jens Axboe
2022-09-26 19:20 ` Pankaj Raghav
2022-09-26 19:25 ` Jens Axboe
2022-09-27 15:20 ` Pankaj Raghav
2022-09-27 16:04 ` Jens Axboe
2022-09-27 16:51 ` Christoph Hellwig
2022-09-27 16:52 ` Jens Axboe
2022-09-27 23:07 ` Damien Le Moal
2022-09-27 23:10 ` Damien Le Moal
2022-09-27 23:13 ` Jens Axboe
2022-09-27 23:12 ` Jens Axboe
2022-09-27 23:35 ` Damien Le Moal
2022-09-28 11:57 ` Pankaj Raghav
2022-09-28 22:19 ` Damien Le Moal
[not found] ` <CGME20220925185351eucas1p1e0c37396c09611509c0b18bdcdeddfe1@eucas1p1.samsung.com>
2022-09-25 18:53 ` [PATCH 2/2] block: use blk_mq_plug() in blk_execute_rq_nowait() Pankaj Raghav
2022-09-25 22:56 ` Damien Le Moal
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