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Commit 26e85fcd authored by Martin K. Petersen's avatar Martin K. Petersen Committed by James Bottomley
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[SCSI] sd: Permit merged discard requests 



Support requests with more than one bio payload for discards. The total
number of bytes to be discarded is stored in req->__data_len and used in
sd_done() to complete the I/O.

Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarJames Bottomley <JBottomley@Parallels.com>
parent 3c6bdaea

drivers/scsi/sd.c

+19 −13
Original line number Diff line number Diff line
@@ -583,29 +583,26 @@ static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode) 
}



/**

 * scsi_setup_discard_cmnd - unmap blocks on thinly provisioned device

 * sd_setup_discard_cmnd - unmap blocks on thinly provisioned device

 * @sdp: scsi device to operate one

 * @rq: Request to prepare

 *

 * Will issue either UNMAP or WRITE SAME(16) depending on preference

 * indicated by target device.

 **/

static int scsi_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq)

static int sd_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq)

{

	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);

	struct bio *bio = rq->bio;

	sector_t sector = bio->bi_sector;

	unsigned int nr_sectors = bio_sectors(bio);

	sector_t sector = blk_rq_pos(rq);

	unsigned int nr_sectors = blk_rq_sectors(rq);

	unsigned int nr_bytes = blk_rq_bytes(rq);

	unsigned int len;

	int ret;

	char *buf;

	struct page *page;



	if (sdkp->device->sector_size == 4096) {

		sector >>= 3;

		nr_sectors >>= 3;

	}



	sector >>= ilog2(sdp->sector_size) - 9;

	nr_sectors >>= ilog2(sdp->sector_size) - 9;

	rq->timeout = SD_TIMEOUT;



	memset(rq->cmd, 0, rq->cmd_len);
@@ -660,6 +657,7 @@ static int scsi_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq) 
	blk_add_request_payload(rq, page, len);

	ret = scsi_setup_blk_pc_cmnd(sdp, rq);

	rq->buffer = page_address(page);

	rq->__data_len = nr_bytes;



out:

	if (ret != BLKPREP_OK) {
@@ -712,7 +710,7 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq) 
	 * block PC requests to make life easier.

	 */

	if (rq->cmd_flags & REQ_DISCARD) {

		ret = scsi_setup_discard_cmnd(sdp, rq);

		ret = sd_setup_discard_cmnd(sdp, rq);

		goto out;

	} else if (rq->cmd_flags & REQ_FLUSH) {

		ret = scsi_setup_flush_cmnd(sdp, rq);
@@ -1482,12 +1480,20 @@ static int sd_done(struct scsi_cmnd *SCpnt) 
	unsigned int good_bytes = result ? 0 : scsi_bufflen(SCpnt);

	struct scsi_sense_hdr sshdr;

	struct scsi_disk *sdkp = scsi_disk(SCpnt->request->rq_disk);

	struct request *req = SCpnt->request;

	int sense_valid = 0;

	int sense_deferred = 0;

	unsigned char op = SCpnt->cmnd[0];



	if ((SCpnt->request->cmd_flags & REQ_DISCARD) && !result)

	if (req->cmd_flags & REQ_DISCARD) {

		if (!result) {

			good_bytes = blk_rq_bytes(req);

			scsi_set_resid(SCpnt, 0);

		} else {

			good_bytes = 0;

			scsi_set_resid(SCpnt, blk_rq_bytes(req));

		}

	}



	if (result) {

		sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr);