Commit 8ae12666 authored by Kent Overstreet's avatar Kent Overstreet Committed by Jens Axboe
Browse files

block: kill merge_bvec_fn() completely 



As generic_make_request() is now able to handle arbitrarily sized bios,
it's no longer necessary for each individual block driver to define its
own ->merge_bvec_fn() callback. Remove every invocation completely.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Sage Weil <sage@inktank.com>
Cc: Alex Elder <elder@kernel.org>
Cc: ceph-devel@vger.kernel.org
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: Neil Brown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Acked-by: NeilBrown <neilb@suse.de> (for the 'md' bits)
Acked-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarKent Overstreet <kent.overstreet@gmail.com>
[dpark: also remove ->merge_bvec_fn() in dm-thin as well as
 dm-era-target, and resolve merge conflicts]
Signed-off-by: default avatarDongsu Park <dpark@posteo.net>
Signed-off-by: default avatarMing Lin <ming.l@ssi.samsung.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 7140aafc

block/blk-merge.c

+3 −14
Original line number Diff line number Diff line
@@ -69,24 +69,13 @@ static struct bio *blk_bio_segment_split(struct request_queue *q, 
	struct bio *split;

	struct bio_vec bv, bvprv;

	struct bvec_iter iter;

	unsigned seg_size = 0, nsegs = 0;

	unsigned seg_size = 0, nsegs = 0, sectors = 0;

	int prev = 0;



	struct bvec_merge_data bvm = {

		.bi_bdev	= bio->bi_bdev,

		.bi_sector	= bio->bi_iter.bi_sector,

		.bi_size	= 0,

		.bi_rw		= bio->bi_rw,

	};



	bio_for_each_segment(bv, bio, iter) {

		if (q->merge_bvec_fn &&

		    q->merge_bvec_fn(q, &bvm, &bv) < (int) bv.bv_len)

			goto split;



		bvm.bi_size += bv.bv_len;

		sectors += bv.bv_len >> 9;



		if (bvm.bi_size >> 9 > queue_max_sectors(q))

		if (sectors > queue_max_sectors(q))

			goto split;



		/*

block/blk-settings.c

+0 −22
Original line number Diff line number Diff line
@@ -53,28 +53,6 @@ void blk_queue_unprep_rq(struct request_queue *q, unprep_rq_fn *ufn) 
}

EXPORT_SYMBOL(blk_queue_unprep_rq);



/**

 * blk_queue_merge_bvec - set a merge_bvec function for queue

 * @q:		queue

 * @mbfn:	merge_bvec_fn

 *

 * Usually queues have static limitations on the max sectors or segments that

 * we can put in a request. Stacking drivers may have some settings that

 * are dynamic, and thus we have to query the queue whether it is ok to

 * add a new bio_vec to a bio at a given offset or not. If the block device

 * has such limitations, it needs to register a merge_bvec_fn to control

 * the size of bio's sent to it. Note that a block device *must* allow a

 * single page to be added to an empty bio. The block device driver may want

 * to use the bio_split() function to deal with these bio's. By default

 * no merge_bvec_fn is defined for a queue, and only the fixed limits are

 * honored.

 */

void blk_queue_merge_bvec(struct request_queue *q, merge_bvec_fn *mbfn)

{

	q->merge_bvec_fn = mbfn;

}

EXPORT_SYMBOL(blk_queue_merge_bvec);



void blk_queue_softirq_done(struct request_queue *q, softirq_done_fn *fn)

{

	q->softirq_done_fn = fn;

drivers/block/drbd/drbd_int.h

+0 −1
Original line number Diff line number Diff line
@@ -1450,7 +1450,6 @@ extern void do_submit(struct work_struct *ws); 
extern void __drbd_make_request(struct drbd_device *, struct bio *, unsigned long);

extern void drbd_make_request(struct request_queue *q, struct bio *bio);

extern int drbd_read_remote(struct drbd_device *device, struct drbd_request *req);

extern int drbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bvm, struct bio_vec *bvec);

extern int is_valid_ar_handle(struct drbd_request *, sector_t);

drivers/block/drbd/drbd_main.c

+0 −1
Original line number Diff line number Diff line
@@ -2774,7 +2774,6 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig 
	   This triggers a max_bio_size message upon first attach or connect */

	blk_queue_max_hw_sectors(q, DRBD_MAX_BIO_SIZE_SAFE >> 8);

	blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);

	blk_queue_merge_bvec(q, drbd_merge_bvec);

	q->queue_lock = &resource->req_lock;



	device->md_io.page = alloc_page(GFP_KERNEL);

drivers/block/drbd/drbd_req.c

+0 −35
Original line number Diff line number Diff line
@@ -1512,41 +1512,6 @@ void drbd_make_request(struct request_queue *q, struct bio *bio) 
	__drbd_make_request(device, bio, start_jif);

}



/* This is called by bio_add_page().

 *

 * q->max_hw_sectors and other global limits are already enforced there.

 *

 * We need to call down to our lower level device,

 * in case it has special restrictions.

 *

 * We also may need to enforce configured max-bio-bvecs limits.

 *

 * As long as the BIO is empty we have to allow at least one bvec,

 * regardless of size and offset, so no need to ask lower levels.

 */

int drbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bvm, struct bio_vec *bvec)

{

	struct drbd_device *device = (struct drbd_device *) q->queuedata;

	unsigned int bio_size = bvm->bi_size;

	int limit = DRBD_MAX_BIO_SIZE;

	int backing_limit;



	if (bio_size && get_ldev(device)) {

		unsigned int max_hw_sectors = queue_max_hw_sectors(q);

		struct request_queue * const b =

			device->ldev->backing_bdev->bd_disk->queue;

		if (b->merge_bvec_fn) {

			bvm->bi_bdev = device->ldev->backing_bdev;

			backing_limit = b->merge_bvec_fn(b, bvm, bvec);

			limit = min(limit, backing_limit);

		}

		put_ldev(device);

		if ((limit >> 9) > max_hw_sectors)

			limit = max_hw_sectors << 9;

	}

	return limit;

}



void request_timer_fn(unsigned long data)

{

	struct drbd_device *device = (struct drbd_device *) data;

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