nvme: add helper nvme_map_len()

The helper returns the number of bytes that need to be mapped
using PRPs/SGL entries.

Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Ming Lin 2016-03-22 00:24:43 -07:00 committed by Jens Axboe
parent 2e39e0f608
commit 58b4560275
2 changed files with 13 additions and 8 deletions

View File

@ -173,6 +173,14 @@ static inline u64 nvme_block_nr(struct nvme_ns *ns, sector_t sector)
return (sector >> (ns->lba_shift - 9));
}
static inline unsigned nvme_map_len(struct request *rq)
{
if (rq->cmd_flags & REQ_DISCARD)
return sizeof(struct nvme_dsm_range);
else
return blk_rq_bytes(rq);
}
static inline void nvme_setup_flush(struct nvme_ns *ns,
struct nvme_command *cmnd)
{

View File

@ -334,16 +334,11 @@ static __le64 **iod_list(struct request *req)
return (__le64 **)(iod->sg + req->nr_phys_segments);
}
static int nvme_init_iod(struct request *rq, struct nvme_dev *dev)
static int nvme_init_iod(struct request *rq, unsigned size,
struct nvme_dev *dev)
{
struct nvme_iod *iod = blk_mq_rq_to_pdu(rq);
int nseg = rq->nr_phys_segments;
unsigned size;
if (rq->cmd_flags & REQ_DISCARD)
size = sizeof(struct nvme_dsm_range);
else
size = blk_rq_bytes(rq);
if (nseg > NVME_INT_PAGES || size > NVME_INT_BYTES(dev)) {
iod->sg = kmalloc(nvme_iod_alloc_size(dev, size, nseg), GFP_ATOMIC);
@ -637,6 +632,7 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
struct nvme_dev *dev = nvmeq->dev;
struct request *req = bd->rq;
struct nvme_command cmnd;
unsigned map_len;
int ret = BLK_MQ_RQ_QUEUE_OK;
/*
@ -652,7 +648,8 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
}
}
ret = nvme_init_iod(req, dev);
map_len = nvme_map_len(req);
ret = nvme_init_iod(req, map_len, dev);
if (ret)
return ret;