From 03b5929ebb20457e2fd13a701954efa2b2fb7ded Mon Sep 17 00:00:00 2001 From: Ming Lin Date: Tue, 22 Mar 2016 00:24:45 -0700 Subject: [PATCH] nvme: rewrite discard support This rewrites nvme_setup_discard() with blk_add_request_payload(). It allocates only the necessary amount(16 bytes) for the payload. Signed-off-by: Ming Lin Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/nvme/host/pci.c | 68 +++++++++++++++++++++++------------------ 1 file changed, 39 insertions(+), 29 deletions(-) diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index d23ede73537d..0bf7f61a0a89 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -363,6 +363,9 @@ static void nvme_free_iod(struct nvme_dev *dev, struct request *req) __le64 **list = iod_list(req); dma_addr_t prp_dma = iod->first_dma; + if (req->cmd_flags & REQ_DISCARD) + kfree(req->completion_data); + if (iod->npages == 0) dma_pool_free(dev->prp_small_pool, list[0], prp_dma); for (i = 0; i < iod->npages; i++) { @@ -524,7 +527,7 @@ static bool nvme_setup_prps(struct nvme_dev *dev, struct request *req, } static int nvme_map_data(struct nvme_dev *dev, struct request *req, - struct nvme_command *cmnd) + unsigned size, struct nvme_command *cmnd) { struct nvme_iod *iod = blk_mq_rq_to_pdu(req); struct request_queue *q = req->q; @@ -541,7 +544,7 @@ static int nvme_map_data(struct nvme_dev *dev, struct request *req, if (!dma_map_sg(dev->dev, iod->sg, iod->nents, dma_dir)) goto out; - if (!nvme_setup_prps(dev, req, blk_rq_bytes(req))) + if (!nvme_setup_prps(dev, req, size)) goto out_unmap; ret = BLK_MQ_RQ_QUEUE_ERROR; @@ -590,35 +593,41 @@ static void nvme_unmap_data(struct nvme_dev *dev, struct request *req) nvme_free_iod(dev, req); } -/* - * We reuse the small pool to allocate the 16-byte range here as it is not - * worth having a special pool for these or additional cases to handle freeing - * the iod. - */ -static int nvme_setup_discard(struct nvme_queue *nvmeq, struct nvme_ns *ns, - struct request *req, struct nvme_command *cmnd) +static inline int nvme_setup_discard(struct nvme_ns *ns, struct request *req, + struct nvme_command *cmnd) { - struct nvme_iod *iod = blk_mq_rq_to_pdu(req); struct nvme_dsm_range *range; + struct page *page; + int offset; + unsigned int nr_bytes = blk_rq_bytes(req); - range = dma_pool_alloc(nvmeq->dev->prp_small_pool, GFP_ATOMIC, - &iod->first_dma); + range = kmalloc(sizeof(*range), GFP_ATOMIC); if (!range) return BLK_MQ_RQ_QUEUE_BUSY; - iod_list(req)[0] = (__le64 *)range; - iod->npages = 0; range->cattr = cpu_to_le32(0); - range->nlb = cpu_to_le32(blk_rq_bytes(req) >> ns->lba_shift); + range->nlb = cpu_to_le32(nr_bytes >> ns->lba_shift); range->slba = cpu_to_le64(nvme_block_nr(ns, blk_rq_pos(req))); memset(cmnd, 0, sizeof(*cmnd)); cmnd->dsm.opcode = nvme_cmd_dsm; cmnd->dsm.nsid = cpu_to_le32(ns->ns_id); - cmnd->dsm.prp1 = cpu_to_le64(iod->first_dma); cmnd->dsm.nr = 0; cmnd->dsm.attributes = cpu_to_le32(NVME_DSMGMT_AD); - return BLK_MQ_RQ_QUEUE_OK; + + req->completion_data = range; + page = virt_to_page(range); + offset = offset_in_page(range); + blk_add_request_payload(req, page, offset, sizeof(*range)); + + /* + * we set __data_len back to the size of the area to be discarded + * on disk. This allows us to report completion on the full amount + * of blocks described by the request. + */ + req->__data_len = nr_bytes; + + return 0; } /* @@ -653,19 +662,20 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx, if (ret) return ret; - if (req->cmd_flags & REQ_DISCARD) { - ret = nvme_setup_discard(nvmeq, ns, req, &cmnd); - } else { - if (req->cmd_type == REQ_TYPE_DRV_PRIV) - memcpy(&cmnd, req->cmd, sizeof(cmnd)); - else if (req->cmd_flags & REQ_FLUSH) - nvme_setup_flush(ns, &cmnd); - else - nvme_setup_rw(ns, req, &cmnd); + if (req->cmd_type == REQ_TYPE_DRV_PRIV) + memcpy(&cmnd, req->cmd, sizeof(cmnd)); + else if (req->cmd_flags & REQ_FLUSH) + nvme_setup_flush(ns, &cmnd); + else if (req->cmd_flags & REQ_DISCARD) + ret = nvme_setup_discard(ns, req, &cmnd); + else + nvme_setup_rw(ns, req, &cmnd); - if (req->nr_phys_segments) - ret = nvme_map_data(dev, req, &cmnd); - } + if (ret) + goto out; + + if (req->nr_phys_segments) + ret = nvme_map_data(dev, req, map_len, &cmnd); if (ret) goto out;