Commit 5b2322e4 authored by Logan Gunthorpe's avatar Logan Gunthorpe Committed by Bjorn Helgaas
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nvmet: Introduce helper functions to allocate and free request SGLs

Add helpers to allocate and free the SGL in a struct nvmet_req:

  int nvmet_req_alloc_sgl(struct nvmet_req *req)
  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 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: default avatarLogan Gunthorpe <>
Signed-off-by: default avatarBjorn Helgaas <>
Reviewed-by: default avatarChristoph Hellwig <>
Acked-by: default avatarSagi Grimberg <>
parent e0596ab2
......@@ -725,6 +725,24 @@ void nvmet_req_execute(struct nvmet_req *req)
int nvmet_req_alloc_sgl(struct nvmet_req *req)
req->sg = sgl_alloc(req->transfer_len, GFP_KERNEL, &req->sg_cnt);
if (!req->sg)
return -ENOMEM;
return 0;
void nvmet_req_free_sgl(struct nvmet_req *req)
req->sg = NULL;
req->sg_cnt = 0;
static inline bool nvmet_cc_en(u32 cc)
return (cc >> NVME_CC_EN_SHIFT) & 0x1;
......@@ -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);
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);
......@@ -503,7 +503,7 @@ static void nvmet_rdma_release_rsp(struct nvmet_rdma_rsp *rsp)
if (rsp-> != rsp->cmd->inline_sg)
if (unlikely(!list_empty_careful(&queue->rsp_wr_wait_list)))
......@@ -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-> = sgl_alloc(len, GFP_KERNEL, &rsp->req.sg_cnt);
if (!rsp->
ret = nvmet_req_alloc_sgl(&rsp->req);
if (ret < 0)
goto error_out;
ret = rdma_rw_ctx_init(&rsp->rw, cm_id->qp, cm_id->port_num,
rsp->, rsp->req.sg_cnt, 0, addr, key,
if (ret < 0)
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;
rsp->req.transfer_len = 0;
static u16 nvmet_rdma_map_sgl(struct nvmet_rdma_rsp *rsp)
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