Commit 1afb20f3 authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by Jens Axboe
Browse files

block: make rq_init() do a full memset() 



This requires moving rq_init() from get_request() to blk_alloc_request().
The upside is that we can now require an rq_init() from any path that
wishes to hand the request to the block layer.

rq_init() will be exported for the code that uses struct request
without blk_get_request.

This is a preparation for large command support, which needs to
initialize struct request in a proper way (that is, just doing a
memset() will not work).

Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent c3270e57

block/blk-barrier.c

+1 −6
Original line number Diff line number Diff line
@@ -143,10 +143,8 @@ static void queue_flush(struct request_queue *q, unsigned which) 
		end_io = post_flush_end_io;

	}



	rq->cmd_flags = REQ_HARDBARRIER;

	rq_init(q, rq);

	rq->elevator_private = NULL;

	rq->elevator_private2 = NULL;

	rq->cmd_flags = REQ_HARDBARRIER;

	rq->rq_disk = q->bar_rq.rq_disk;

	rq->end_io = end_io;

	q->prepare_flush_fn(q, rq);
@@ -167,14 +165,11 @@ static inline struct request *start_ordered(struct request_queue *q, 
	blkdev_dequeue_request(rq);

	q->orig_bar_rq = rq;

	rq = &q->bar_rq;

	rq->cmd_flags = 0;

	rq_init(q, rq);

	if (bio_data_dir(q->orig_bar_rq->bio) == WRITE)

		rq->cmd_flags |= REQ_RW;

	if (q->ordered & QUEUE_ORDERED_FUA)

		rq->cmd_flags |= REQ_FUA;

	rq->elevator_private = NULL;

	rq->elevator_private2 = NULL;

	init_request_from_bio(rq, q->orig_bar_rq->bio);

	rq->end_io = bar_end_io;

block/blk-core.c

+4 −26
Original line number Diff line number Diff line
@@ -107,40 +107,18 @@ struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev) 
}

EXPORT_SYMBOL(blk_get_backing_dev_info);



/*

 * We can't just memset() the structure, since the allocation path

 * already stored some information in the request.

 */

void rq_init(struct request_queue *q, struct request *rq)

{

	memset(rq, 0, sizeof(*rq));



	INIT_LIST_HEAD(&rq->queuelist);

	INIT_LIST_HEAD(&rq->donelist);

	rq->q = q;

	rq->sector = rq->hard_sector = (sector_t) -1;

	rq->nr_sectors = rq->hard_nr_sectors = 0;

	rq->current_nr_sectors = rq->hard_cur_sectors = 0;

	rq->bio = rq->biotail = NULL;

	INIT_HLIST_NODE(&rq->hash);

	RB_CLEAR_NODE(&rq->rb_node);

	rq->rq_disk = NULL;

	rq->nr_phys_segments = 0;

	rq->nr_hw_segments = 0;

	rq->ioprio = 0;

	rq->special = NULL;

	rq->buffer = NULL;

	rq->tag = -1;

	rq->errors = 0;

	rq->ref_count = 1;

	rq->cmd_len = 0;

	memset(rq->cmd, 0, sizeof(rq->cmd));

	rq->data_len = 0;

	rq->extra_len = 0;

	rq->sense_len = 0;

	rq->data = NULL;

	rq->sense = NULL;

	rq->end_io = NULL;

	rq->end_io_data = NULL;

	rq->next_rq = NULL;

}



static void req_bio_endio(struct request *rq, struct bio *bio,
@@ -607,6 +585,8 @@ blk_alloc_request(struct request_queue *q, int rw, int priv, gfp_t gfp_mask) 
	if (!rq)

		return NULL;



	rq_init(q, rq);



	/*

	 * first three bits are identical in rq->cmd_flags and bio->bi_rw,

	 * see bio.h and blkdev.h
@@ -789,8 +769,6 @@ rq_starved: 
	if (ioc_batching(q, ioc))

		ioc->nr_batch_requests--;



	rq_init(q, rq);



	blk_add_trace_generic(q, bio, rw, BLK_TA_GETRQ);

out:

	return rq;

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