[PATCH] nvmet-rdma: Don't use the inline buffer in order to avoid allocation for small reads
From: Sagi Grimberg <hidden>
Date: 2016-08-01 08:36:39
Also in:
linux-nvme
Subsystem:
nvm express target driver, the rest · Maintainers:
Christoph Hellwig, Sagi Grimberg, Chaitanya Kulkarni, Linus Torvalds
Under extreme conditions this might cause data corruptions. By doing that we we repost the buffer and then post this buffer for the device to send. If we happen to use shared receive queues the device might write to the buffer before it sends it (there is no ordering between send and recv queues). Without SRQs we probably won't get that if the host doesn't mis-behave and send more than we allowed it, but relying on that is not really a good idea. Signed-off-by: Sagi Grimberg <redacted> --- drivers/nvme/target/rdma.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index e06d504bdf0c..4e83d92d6bdd 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c@@ -615,15 +615,10 @@ static u16 nvmet_rdma_map_sgl_keyed(struct nvmet_rdma_rsp *rsp, if (!len) return 0; - /* use the already allocated data buffer if possible */ - if (len <= NVMET_RDMA_INLINE_DATA_SIZE && rsp->queue->host_qid) { - nvmet_rdma_use_inline_sg(rsp, len, 0); - } else { - status = nvmet_rdma_alloc_sgl(&rsp->req.sg, &rsp->req.sg_cnt, - len); - if (status) - return status; - } + status = nvmet_rdma_alloc_sgl(&rsp->req.sg, &rsp->req.sg_cnt, + len); + if (status) + return status; ret = rdma_rw_ctx_init(&rsp->rw, cm_id->qp, cm_id->port_num, rsp->req.sg, rsp->req.sg_cnt, 0, addr, key,
--
1.9.1
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