Commit b35ba01e authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

nvme: support ranged discard requests 



NVMe supports up to 256 ranges per DSM command, so wire up support
for ranged discards up to that limit.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 1e739730

drivers/nvme/host/core.c

+23 −7
Original line number Diff line number Diff line
@@ -238,26 +238,38 @@ static inline void nvme_setup_flush(struct nvme_ns *ns, 
static inline int nvme_setup_discard(struct nvme_ns *ns, struct request *req,

		struct nvme_command *cmnd)

{

	unsigned short segments = blk_rq_nr_discard_segments(req), n = 0;

	struct nvme_dsm_range *range;

	unsigned int nr_bytes = blk_rq_bytes(req);

	struct bio *bio;



	range = kmalloc(sizeof(*range), GFP_ATOMIC);

	range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC);

	if (!range)

		return BLK_MQ_RQ_QUEUE_BUSY;



	range->cattr = cpu_to_le32(0);

	range->nlb = cpu_to_le32(nr_bytes >> ns->lba_shift);

	range->slba = cpu_to_le64(nvme_block_nr(ns, blk_rq_pos(req)));

	__rq_for_each_bio(bio, req) {

		u64 slba = nvme_block_nr(ns, bio->bi_iter.bi_sector);

		u32 nlb = bio->bi_iter.bi_size >> ns->lba_shift;



		range[n].cattr = cpu_to_le32(0);

		range[n].nlb = cpu_to_le32(nlb);

		range[n].slba = cpu_to_le64(slba);

		n++;

	}



	if (WARN_ON_ONCE(n != segments)) {

		kfree(range);

		return BLK_MQ_RQ_QUEUE_ERROR;

	}



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

	cmnd->dsm.opcode = nvme_cmd_dsm;

	cmnd->dsm.nsid = cpu_to_le32(ns->ns_id);

	cmnd->dsm.nr = 0;

	cmnd->dsm.nr = segments - 1;

	cmnd->dsm.attributes = cpu_to_le32(NVME_DSMGMT_AD);



	req->special_vec.bv_page = virt_to_page(range);

	req->special_vec.bv_offset = offset_in_page(range);

	req->special_vec.bv_len = sizeof(*range);

	req->special_vec.bv_len = sizeof(*range) * segments;

	req->rq_flags |= RQF_SPECIAL_PAYLOAD;



	return BLK_MQ_RQ_QUEUE_OK;
@@ -871,6 +883,9 @@ static void nvme_config_discard(struct nvme_ns *ns) 
	struct nvme_ctrl *ctrl = ns->ctrl;

	u32 logical_block_size = queue_logical_block_size(ns->queue);



	BUILD_BUG_ON(PAGE_SIZE / sizeof(struct nvme_dsm_range) <

			NVME_DSM_MAX_RANGES);



	if (ctrl->quirks & NVME_QUIRK_DISCARD_ZEROES)

		ns->queue->limits.discard_zeroes_data = 1;

	else
@@ -879,6 +894,7 @@ static void nvme_config_discard(struct nvme_ns *ns) 
	ns->queue->limits.discard_alignment = logical_block_size;

	ns->queue->limits.discard_granularity = logical_block_size;

	blk_queue_max_discard_sectors(ns->queue, UINT_MAX);

	blk_queue_max_discard_segments(ns->queue, NVME_DSM_MAX_RANGES);

	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, ns->queue);

}

include/linux/nvme.h

+2 −0
Original line number Diff line number Diff line
@@ -553,6 +553,8 @@ enum { 
	NVME_DSMGMT_AD		= 1 << 2,

};



#define NVME_DSM_MAX_RANGES	256



struct nvme_dsm_range {

	__le32			cattr;

	__le32			nlb;