Commit e2a60da7 authored by Martin K. Petersen's avatar Martin K. Petersen Committed by Jens Axboe
Browse files

block: Clean up special command handling logic 



Remove special-casing of non-rw fs style requests (discard). The nomerge
flags are consolidated in blk_types.h, and rq_mergeable() and
bio_mergeable() have been modified to use them.

bio_is_rw() is used in place of bio_has_data() a few places. This is
done to to distinguish true reads and writes from other fs type requests
that carry a payload (e.g. write same).

Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Acked-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent d41570b7

block/blk-core.c

+6 −7
Original line number Diff line number Diff line
@@ -1657,7 +1657,7 @@ generic_make_request_checks(struct bio *bio) 
		goto end_io;

	}



	if (unlikely(!(bio->bi_rw & REQ_DISCARD) &&

	if (likely(bio_is_rw(bio) &&

		   nr_sectors > queue_max_hw_sectors(q))) {

		printk(KERN_ERR "bio too big device %s (%u > %u)\n",

		       bdevname(bio->bi_bdev, b),
@@ -1699,8 +1699,7 @@ generic_make_request_checks(struct bio *bio) 


	if ((bio->bi_rw & REQ_DISCARD) &&

	    (!blk_queue_discard(q) ||

	     ((bio->bi_rw & REQ_SECURE) &&

	      !blk_queue_secdiscard(q)))) {

	     ((bio->bi_rw & REQ_SECURE) && !blk_queue_secdiscard(q)))) {

		err = -EOPNOTSUPP;

		goto end_io;

	}
@@ -1818,7 +1817,7 @@ void submit_bio(int rw, struct bio *bio) 
	 * If it's a regular read/write or a barrier with data attached,

	 * go through the normal accounting stuff before submission.

	 */

	if (bio_has_data(bio) && !(rw & REQ_DISCARD)) {

	if (bio_has_data(bio)) {

		if (rw & WRITE) {

			count_vm_events(PGPGOUT, count);

		} else {
@@ -1864,7 +1863,7 @@ EXPORT_SYMBOL(submit_bio); 
 */

int blk_rq_check_limits(struct request_queue *q, struct request *rq)

{

	if (rq->cmd_flags & REQ_DISCARD)

	if (!rq_mergeable(rq))

		return 0;



	if (blk_rq_sectors(rq) > queue_max_sectors(q) ||
@@ -2338,7 +2337,7 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes) 
	req->buffer = bio_data(req->bio);



	/* update sector only for requests with clear definition of sector */

	if (req->cmd_type == REQ_TYPE_FS || (req->cmd_flags & REQ_DISCARD))

	if (req->cmd_type == REQ_TYPE_FS)

		req->__sector += total_bytes >> 9;



	/* mixed attributes always follow the first bio */

block/blk-merge.c

+1 −21
Original line number Diff line number Diff line
@@ -417,18 +417,6 @@ static int attempt_merge(struct request_queue *q, struct request *req, 
	if (!rq_mergeable(req) || !rq_mergeable(next))

		return 0;



	/*

	 * Don't merge file system requests and discard requests

	 */

	if ((req->cmd_flags & REQ_DISCARD) != (next->cmd_flags & REQ_DISCARD))

		return 0;



	/*

	 * Don't merge discard requests and secure discard requests

	 */

	if ((req->cmd_flags & REQ_SECURE) != (next->cmd_flags & REQ_SECURE))

		return 0;



	/*

	 * not contiguous

	 */
@@ -521,15 +509,7 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq, 


bool blk_rq_merge_ok(struct request *rq, struct bio *bio)

{

	if (!rq_mergeable(rq))

		return false;



	/* don't merge file system requests and discard requests */

	if ((bio->bi_rw & REQ_DISCARD) != (rq->bio->bi_rw & REQ_DISCARD))

		return false;



	/* don't merge discard requests and secure discard requests */

	if ((bio->bi_rw & REQ_SECURE) != (rq->bio->bi_rw & REQ_SECURE))

	if (!rq_mergeable(rq) || !bio_mergeable(bio))

		return false;



	/* different data direction or already started, don't merge */

block/blk.h

+2 −3
Original line number Diff line number Diff line
@@ -171,14 +171,13 @@ static inline int queue_congestion_off_threshold(struct request_queue *q) 
 *

 *	a) it's attached to a gendisk, and

 *	b) the queue had IO stats enabled when this request was started, and

 *	c) it's a file system request or a discard request

 *	c) it's a file system request

 */

static inline int blk_do_io_stat(struct request *rq)

{

	return rq->rq_disk &&

	       (rq->cmd_flags & REQ_IO_STAT) &&

	       (rq->cmd_type == REQ_TYPE_FS ||

	        (rq->cmd_flags & REQ_DISCARD));

		(rq->cmd_type == REQ_TYPE_FS);

}



/*

block/elevator.c

+2 −4
Original line number Diff line number Diff line
@@ -562,8 +562,7 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where) 


	if (rq->cmd_flags & REQ_SOFTBARRIER) {

		/* barriers are scheduling boundary, update end_sector */

		if (rq->cmd_type == REQ_TYPE_FS ||

		    (rq->cmd_flags & REQ_DISCARD)) {

		if (rq->cmd_type == REQ_TYPE_FS) {

			q->end_sector = rq_end_sector(rq);

			q->boundary_rq = rq;

		}
@@ -605,8 +604,7 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where) 
		if (elv_attempt_insert_merge(q, rq))

			break;

	case ELEVATOR_INSERT_SORT:

		BUG_ON(rq->cmd_type != REQ_TYPE_FS &&

		       !(rq->cmd_flags & REQ_DISCARD));

		BUG_ON(rq->cmd_type != REQ_TYPE_FS);

		rq->cmd_flags |= REQ_SORTED;

		q->nr_sorted++;

		if (rq_mergeable(rq)) {

include/linux/bio.h

+21 −2
Original line number Diff line number Diff line
@@ -386,9 +386,28 @@ static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx, 
/*

 * Check whether this bio carries any data or not. A NULL bio is allowed.

 */

static inline int bio_has_data(struct bio *bio)

static inline bool bio_has_data(struct bio *bio)

{

	return bio && bio->bi_io_vec != NULL;

	if (bio && bio->bi_vcnt)

		return true;



	return false;

}



static inline bool bio_is_rw(struct bio *bio)

{

	if (!bio_has_data(bio))

		return false;



	return true;

}



static inline bool bio_mergeable(struct bio *bio)

{

	if (bio->bi_rw & REQ_NOMERGE_FLAGS)

		return false;



	return true;

}



/*

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