diff mbox series

[1/2] block: remove the write_hint field from struct request

Message ID 20241112170050.1612998-2-hch@lst.de
State New
Headers show
Series [1/2] block: remove the write_hint field from struct request | expand

Commit Message

Christoph Hellwig Nov. 12, 2024, 5 p.m. UTC
The write_hint is only used for read/write requests, which must have a
bio attached to them.  Just use the bio field instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-merge.c      | 16 ++++++++++------
 block/blk-mq.c         |  2 --
 drivers/scsi/sd.c      |  6 +++---
 include/linux/blk-mq.h |  1 -
 4 files changed, 13 insertions(+), 12 deletions(-)

Comments

Bart Van Assche Nov. 12, 2024, 6:29 p.m. UTC | #1
On 11/12/24 9:00 AM, Christoph Hellwig wrote:
> -	/* Don't merge requests with different write hints. */
> -	if (req->write_hint != next->write_hint)
> -		return NULL;
> +	if (req->bio && next->bio) {
> +		/* Don't merge requests with different write hints. */
> +		if (req->bio->bi_write_hint != next->bio->bi_write_hint)
> +			return NULL;
> +	}

The above two if-statements can be combined into a single if-statement.

> @@ -1001,9 +1003,11 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
>   	if (!bio_crypt_rq_ctx_compatible(rq, bio))
>   		return false;
>   
> -	/* Don't merge requests with different write hints. */
> -	if (rq->write_hint != bio->bi_write_hint)
> -		return false;
> +	if (rq->bio) {
> +		/* Don't merge requests with different write hints. */
> +		if (rq->bio->bi_write_hint != bio->bi_write_hint)
> +			return false;
> +	}

Same comment here: the above two if-statements can also be combined into 
a single if-statement.

Otherwise this patch looks good to me.

Thanks,

Bart.
Bart Van Assche Nov. 12, 2024, 6:32 p.m. UTC | #2
On 11/12/24 10:29 AM, Bart Van Assche wrote:
> On 11/12/24 9:00 AM, Christoph Hellwig wrote:
>> -    /* Don't merge requests with different write hints. */
>> -    if (req->write_hint != next->write_hint)
>> -        return NULL;
>> +    if (req->bio && next->bio) {
>> +        /* Don't merge requests with different write hints. */
>> +        if (req->bio->bi_write_hint != next->bio->bi_write_hint)
>> +            return NULL;
>> +    }
> 
> The above two if-statements can be combined into a single if-statement.
> 
>> @@ -1001,9 +1003,11 @@ bool blk_rq_merge_ok(struct request *rq, struct 
>> bio *bio)
>>       if (!bio_crypt_rq_ctx_compatible(rq, bio))
>>           return false;
>> -    /* Don't merge requests with different write hints. */
>> -    if (rq->write_hint != bio->bi_write_hint)
>> -        return false;
>> +    if (rq->bio) {
>> +        /* Don't merge requests with different write hints. */
>> +        if (rq->bio->bi_write_hint != bio->bi_write_hint)
>> +            return false;
>> +    }
> 
> Same comment here: the above two if-statements can also be combined into 
> a single if-statement.
> 
> Otherwise this patch looks good to me.

(replying to my own email)

Since apparently the goal is to minimize diffs in the next patch,

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
diff mbox series

Patch

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 7b0af8317c1c..2306014c108d 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -867,9 +867,11 @@  static struct request *attempt_merge(struct request_queue *q,
 	if (rq_data_dir(req) != rq_data_dir(next))
 		return NULL;
 
-	/* Don't merge requests with different write hints. */
-	if (req->write_hint != next->write_hint)
-		return NULL;
+	if (req->bio && next->bio) {
+		/* Don't merge requests with different write hints. */
+		if (req->bio->bi_write_hint != next->bio->bi_write_hint)
+			return NULL;
+	}
 
 	if (req->ioprio != next->ioprio)
 		return NULL;
@@ -1001,9 +1003,11 @@  bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
 	if (!bio_crypt_rq_ctx_compatible(rq, bio))
 		return false;
 
-	/* Don't merge requests with different write hints. */
-	if (rq->write_hint != bio->bi_write_hint)
-		return false;
+	if (rq->bio) {
+		/* Don't merge requests with different write hints. */
+		if (rq->bio->bi_write_hint != bio->bi_write_hint)
+			return false;
+	}
 
 	if (rq->ioprio != bio_prio(bio))
 		return false;
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 5e240a4b6be0..65e6b86d341c 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2660,7 +2660,6 @@  static void blk_mq_bio_to_request(struct request *rq, struct bio *bio,
 		rq->cmd_flags |= REQ_FAILFAST_MASK;
 
 	rq->__sector = bio->bi_iter.bi_sector;
-	rq->write_hint = bio->bi_write_hint;
 	blk_rq_bio_prep(rq, bio, nr_segs);
 	if (bio_integrity(bio))
 		rq->nr_integrity_segments = blk_rq_count_integrity_sg(rq->q,
@@ -3308,7 +3307,6 @@  int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 	}
 	rq->nr_phys_segments = rq_src->nr_phys_segments;
 	rq->ioprio = rq_src->ioprio;
-	rq->write_hint = rq_src->write_hint;
 
 	if (rq->bio && blk_crypto_rq_bio_prep(rq, rq->bio, gfp_mask) < 0)
 		goto free_and_out;
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index ca4bc0ac76ad..8947dab132d7 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1190,8 +1190,8 @@  static u8 sd_group_number(struct scsi_cmnd *cmd)
 	if (!sdkp->rscs)
 		return 0;
 
-	return min3((u32)rq->write_hint, (u32)sdkp->permanent_stream_count,
-		    0x3fu);
+	return min3((u32)rq->bio->bi_write_hint,
+		    (u32)sdkp->permanent_stream_count, 0x3fu);
 }
 
 static blk_status_t sd_setup_rw32_cmnd(struct scsi_cmnd *cmd, bool write,
@@ -1389,7 +1389,7 @@  static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *cmd)
 		ret = sd_setup_rw16_cmnd(cmd, write, lba, nr_blocks,
 					 protect | fua, dld);
 	} else if ((nr_blocks > 0xff) || (lba > 0x1fffff) ||
-		   sdp->use_10_for_rw || protect || rq->write_hint) {
+		   sdp->use_10_for_rw || protect || rq->bio->bi_write_hint) {
 		ret = sd_setup_rw10_cmnd(cmd, write, lba, nr_blocks,
 					 protect | fua);
 	} else {
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 2035fad3131f..2804fe181d9d 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -156,7 +156,6 @@  struct request {
 	struct blk_crypto_keyslot *crypt_keyslot;
 #endif
 
-	enum rw_hint write_hint;
 	unsigned short ioprio;
 
 	enum mq_rq_state state;