[PATCH v7 12/13] nvmet: Introduce helper functions to allocate and free request SGLs
From: Logan Gunthorpe <logang@deltatee.com>
Date: 2018-09-25 16:23:01
Also in:
linux-nvme, linux-pci, linux-rdma, lkml, nvdimm
Subsystem:
nvm express target driver, the rest · Maintainers:
Christoph Hellwig, Sagi Grimberg, Chaitanya Kulkarni, Linus Torvalds
Add helpers to allocate and free the SGL in a struct nvmet_req: int nvmet_req_alloc_sgl(struct nvmet_req *req, struct nvmet_sq *sq) void nvmet_req_free_sgl(struct nvmet_req *req) This will be expanded in a future patch to implement peer-to-peer memory DMAs and should be common with all target drivers. The presently unused 'sq' argument in the alloc function will be necessary to decide whether to use peer-to-peer memory and obtain the correct provider to allocate the memory. The new helpers are used in nvmet-rdma. Seeing we use req.transfer_len as the length of the SGL it is set earlier and cleared on any error. It also seems to be unnecessary to accumulate the length as the map_sgl functions should only ever be called once per request. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Acked-by: Sagi Grimberg <sagi@grimberg.me> Cc: Christoph Hellwig <hch@lst.de> --- drivers/nvme/target/core.c | 18 ++++++++++++++++++ drivers/nvme/target/nvmet.h | 2 ++ drivers/nvme/target/rdma.c | 20 ++++++++++++-------- 3 files changed, 32 insertions(+), 8 deletions(-)
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index b5ec96abd048..bddd1599b826 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c@@ -725,6 +725,24 @@ void nvmet_req_execute(struct nvmet_req *req) } EXPORT_SYMBOL_GPL(nvmet_req_execute); +int nvmet_req_alloc_sgl(struct nvmet_req *req, struct nvmet_sq *sq) +{ + req->sg = sgl_alloc(req->transfer_len, GFP_KERNEL, &req->sg_cnt); + if (!req->sg) + return -ENOMEM; + + return 0; +} +EXPORT_SYMBOL_GPL(nvmet_req_alloc_sgl); + +void nvmet_req_free_sgl(struct nvmet_req *req) +{ + sgl_free(req->sg); + req->sg = NULL; + req->sg_cnt = 0; +} +EXPORT_SYMBOL_GPL(nvmet_req_free_sgl); + static inline bool nvmet_cc_en(u32 cc) { return (cc >> NVME_CC_EN_SHIFT) & 0x1;
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index ec9af4ee03b6..7d6cb61021e4 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h@@ -336,6 +336,8 @@ bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq, void nvmet_req_uninit(struct nvmet_req *req); void nvmet_req_execute(struct nvmet_req *req); void nvmet_req_complete(struct nvmet_req *req, u16 status); +int nvmet_req_alloc_sgl(struct nvmet_req *req, struct nvmet_sq *sq); +void nvmet_req_free_sgl(struct nvmet_req *req); void nvmet_cq_setup(struct nvmet_ctrl *ctrl, struct nvmet_cq *cq, u16 qid, u16 size);
diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index bfc4da660bb4..b0d0cedc74bb 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c@@ -503,7 +503,7 @@ static void nvmet_rdma_release_rsp(struct nvmet_rdma_rsp *rsp) } if (rsp->req.sg != rsp->cmd->inline_sg) - sgl_free(rsp->req.sg); + nvmet_req_free_sgl(&rsp->req); if (unlikely(!list_empty_careful(&queue->rsp_wr_wait_list))) nvmet_rdma_process_wr_wait_list(queue);
@@ -652,24 +652,24 @@ static u16 nvmet_rdma_map_sgl_keyed(struct nvmet_rdma_rsp *rsp, { struct rdma_cm_id *cm_id = rsp->queue->cm_id; u64 addr = le64_to_cpu(sgl->addr); - u32 len = get_unaligned_le24(sgl->length); u32 key = get_unaligned_le32(sgl->key); int ret; + rsp->req.transfer_len = get_unaligned_le24(sgl->length); + /* no data command? */ - if (!len) + if (!rsp->req.transfer_len) return 0; - rsp->req.sg = sgl_alloc(len, GFP_KERNEL, &rsp->req.sg_cnt); - if (!rsp->req.sg) - return NVME_SC_INTERNAL; + ret = nvmet_req_alloc_sgl(&rsp->req, &rsp->queue->nvme_sq); + if (ret < 0) + goto error_out; ret = rdma_rw_ctx_init(&rsp->rw, cm_id->qp, cm_id->port_num, rsp->req.sg, rsp->req.sg_cnt, 0, addr, key, nvmet_data_dir(&rsp->req)); if (ret < 0) - return NVME_SC_INTERNAL; - rsp->req.transfer_len += len; + goto error_out; rsp->n_rdma += ret; if (invalidate) {
@@ -678,6 +678,10 @@ static u16 nvmet_rdma_map_sgl_keyed(struct nvmet_rdma_rsp *rsp, } return 0; + +error_out: + rsp->req.transfer_len = 0; + return NVME_SC_INTERNAL; } static u16 nvmet_rdma_map_sgl(struct nvmet_rdma_rsp *rsp)
--
2.19.0