On 9/29/22 16:47, Pankaj Raghav wrote:
> The current implementation of blk_mq_plug() disables plugging for all
> operations that involves a transfer to the device as we just check if
> the last bit in op_is_write() function.
>
> Modify blk_mq_plug() to disable plugging only for REQ_OP_WRITE and
> REQ_OP_WRITE_ZEROS as they might require a zone lock.
>
> Suggested-by: Christoph Hellwig <hch@xxxxxx>
> Suggested-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> Signed-off-by: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxxxxxxxxxxxxx>
> ---
> block/blk-mq.h | 3 ++-
> block/blk-zoned.c | 9 +++------
> include/linux/blkdev.h | 9 +++++++++
> 3 files changed, 14 insertions(+), 7 deletions(-)
>
> diff --git a/block/blk-mq.h b/block/blk-mq.h
> index 8ca453ac243d..0b2870839cdd 100644
> --- a/block/blk-mq.h
> +++ b/block/blk-mq.h
> @@ -312,7 +312,8 @@ static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
> 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)))
> + if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
> + bdev_op_is_zoned_write(bio->bi_bdev, bio_op(bio)))
> return NULL;
>
> /*
> diff --git a/block/blk-zoned.c b/block/blk-zoned.c
> index a264621d4905..db829401d8d0 100644
> --- a/block/blk-zoned.c
> +++ b/block/blk-zoned.c
> @@ -63,13 +63,10 @@ bool blk_req_needs_zone_write_lock(struct request *rq)
> if (!rq->q->disk->seq_zones_wlock)
> return false;
>
> - switch (req_op(rq)) {
> - case REQ_OP_WRITE_ZEROES:
> - case REQ_OP_WRITE:
> + if (bdev_op_is_zoned_write(rq->q->disk->part0, req_op(rq)))
> return blk_rq_zone_is_seq(rq);
> - default:
> - return false;
> - }
> +
> + return false;
> }
> EXPORT_SYMBOL_GPL(blk_req_needs_zone_write_lock);
>
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 8038c5fbde40..74bc30c680d6 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -1300,6 +1300,15 @@ static inline bool bdev_is_zoned(struct block_device *bdev)
> return false;
> }
>
> +static inline bool bdev_op_is_zoned_write(struct block_device *bdev,
> + blk_opf_t op)
> +{
> + if (!bdev_is_zoned(bdev))
> + return false;
> +
> + return op == REQ_OP_WRITE || op == REQ_OP_WRITE_ZEROES;
> +}
> +
> static inline sector_t bdev_zone_sectors(struct block_device *bdev)
> {
> struct request_queue *q = bdev_get_queue(bdev);
--
Damien Le Moal
Western Digital Research
