[PATCH v2] nvme-tcp: Check if request has started before processing it
Sagi Grimberg
sagi at grimberg.me
Fri May 7 16:22:30 PDT 2021
>>> Well, that would require a modification to the CQE specification, no?
>>> fmds was not amused when I proposed that :-(
>>
>> Why would that require a modification to the CQE? it's just using say
>> 4 msbits of the command_id to a running sequence...
>
> I think Hannes was under the impression that the counter proposal wasn't
> part of the "command_id". The host can encode whatever it wants in that
> value, and the controller just has to return the same value.
Yea, maybe something like this?
--
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index e6612971f4eb..7af48827ea56 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1006,7 +1006,7 @@ blk_status_t nvme_setup_cmd(struct nvme_ns *ns,
struct request *req)
return BLK_STS_IOERR;
}
- cmd->common.command_id = req->tag;
+ cmd->common.command_id = nvme_cid(req);
trace_nvme_setup_cmd(req, cmd);
return ret;
}
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 05f31a2c64bb..96abfb0e2ddd 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -158,6 +158,7 @@ enum nvme_quirks {
struct nvme_request {
struct nvme_command *cmd;
union nvme_result result;
+ u8 genctr;
u8 retries;
u8 flags;
u16 status;
@@ -497,6 +498,48 @@ struct nvme_ctrl_ops {
int (*get_address)(struct nvme_ctrl *ctrl, char *buf, int size);
};
+/*
+ * nvme command_id is constructed as such:
+ * | xxxx | xxxxxxxxxxxx |
+ * gen request tag
+ */
+#define nvme_cid_install_genctr(gen) ((gen & 0xf) << 12)
+#define nvme_genctr_from_cid(cid) ((cid & 0xf000) >> 12)
+#define nvme_tag_from_cid(cid) (cid & 0xfff)
+
+static inline u16 nvme_cid(struct request *rq)
+{
+ return nvme_cid_install_genctr(nvme_req(rq)->genctr++) | rq->tag;
+}
+
+static inline struct request *nvme_find_rq(struct blk_mq_tags *tags,
+ u16 command_id)
+{
+ u8 genctr = nvme_genctr_from_cid(command_id);
+ u16 tag = nvme_tag_from_cid(command_id);
+ struct request *rq;
+
+ rq = blk_mq_tag_to_rq(tags, tag);
+ if (unlikely(!rq)) {
+ pr_err("could not locate request for tag %#x\n",
+ tag);
+ return NULL;
+ }
+ if (unlikely(nvme_req(rq)->genctr != genctr)) {
+ dev_err(nvme_req(rq)->ctrl->device,
+ "request %#x genctr mismatch (got %#x expected
%#x)\n",
+ tag, nvme_req(rq)->genctr, genctr);
+ return NULL;
+ }
+ return rq;
+}
+
+static inline struct request *nvme_cid_to_rq(struct blk_mq_tags *tags,
+ u16 command_id)
+{
+ return blk_mq_tag_to_rq(tags, nvme_tag_from_cid(command_id));
+}
+
#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
void nvme_fault_inject_init(struct nvme_fault_inject *fault_inj,
const char *dev_name);
@@ -594,7 +637,8 @@ static inline void nvme_put_ctrl(struct nvme_ctrl *ctrl)
static inline bool nvme_is_aen_req(u16 qid, __u16 command_id)
{
- return !qid && command_id >= NVME_AQ_BLK_MQ_DEPTH;
+ return !qid &&
+ nvme_tag_from_cid(command_id) >= NVME_AQ_BLK_MQ_DEPTH;
}
void nvme_complete_rq(struct request *req);
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index a29b170701fc..92e03f15c9f6 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1017,7 +1017,7 @@ static inline void nvme_handle_cqe(struct
nvme_queue *nvmeq, u16 idx)
return;
}
- req = blk_mq_tag_to_rq(nvme_queue_tagset(nvmeq), command_id);
+ req = nvme_find_rq(nvme_queue_tagset(nvmeq), command_id);
if (unlikely(!req)) {
dev_warn(nvmeq->dev->ctrl.device,
"invalid id %d completed on queue %d\n",
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 203b47a8ec92..ab5b7d175488 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1727,10 +1727,10 @@ static void nvme_rdma_process_nvme_rsp(struct
nvme_rdma_queue *queue,
struct request *rq;
struct nvme_rdma_request *req;
- rq = blk_mq_tag_to_rq(nvme_rdma_tagset(queue), cqe->command_id);
+ rq = nvme_find_rq(nvme_rdma_tagset(queue), cqe->command_id);
if (!rq) {
dev_err(queue->ctrl->ctrl.device,
- "tag 0x%x on QP %#x not found\n",
+ "got bad command_id %#x on QP %#x\n",
cqe->command_id, queue->qp->qp_num);
nvme_rdma_error_recovery(queue->ctrl);
return;
diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 919f6fe69cb3..c51b70aec6dd 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -488,11 +488,11 @@ static int nvme_tcp_process_nvme_cqe(struct
nvme_tcp_queue *queue,
{
struct request *rq;
- rq = blk_mq_tag_to_rq(nvme_tcp_tagset(queue), cqe->command_id);
+ rq = nvme_find_rq(nvme_tcp_tagset(queue), cqe->command_id);
if (!rq) {
dev_err(queue->ctrl->ctrl.device,
- "queue %d tag 0x%x not found\n",
- nvme_tcp_queue_id(queue), cqe->command_id);
+ "got bad cqe.command_id %#x on queue %d\n",
+ cqe->command_id, nvme_tcp_queue_id(queue));
nvme_tcp_error_recovery(&queue->ctrl->ctrl);
return -EINVAL;
}
@@ -509,11 +509,11 @@ static int nvme_tcp_handle_c2h_data(struct
nvme_tcp_queue *queue,
{
struct request *rq;
- rq = blk_mq_tag_to_rq(nvme_tcp_tagset(queue), pdu->command_id);
+ rq = nvme_find_rq(nvme_tcp_tagset(queue), pdu->command_id);
if (!rq) {
dev_err(queue->ctrl->ctrl.device,
- "queue %d tag %#x not found\n",
- nvme_tcp_queue_id(queue), pdu->command_id);
+ "got bad c2hdata.command_id %#x on queue %d\n",
+ pdu->command_id, nvme_tcp_queue_id(queue));
return -ENOENT;
}
@@ -600,7 +600,7 @@ static int nvme_tcp_setup_h2c_data_pdu(struct
nvme_tcp_request *req,
data->hdr.plen =
cpu_to_le32(data->hdr.hlen + hdgst + req->pdu_len + ddgst);
data->ttag = pdu->ttag;
- data->command_id = rq->tag;
+ data->command_id = nvme_cid(rq);
data->data_offset = cpu_to_le32(req->data_sent);
data->data_length = cpu_to_le32(req->pdu_len);
return 0;
@@ -613,11 +613,11 @@ static int nvme_tcp_handle_r2t(struct
nvme_tcp_queue *queue,
struct request *rq;
int ret;
- rq = blk_mq_tag_to_rq(nvme_tcp_tagset(queue), pdu->command_id);
+ rq = nvme_find_rq(nvme_tcp_tagset(queue), pdu->command_id);
if (!rq) {
dev_err(queue->ctrl->ctrl.device,
- "queue %d tag %#x not found\n",
- nvme_tcp_queue_id(queue), pdu->command_id);
+ "got bad r2t.command_id %#x on queue %d\n",
+ pdu->command_id, nvme_tcp_queue_id(queue));
return -ENOENT;
}
req = blk_mq_rq_to_pdu(rq);
@@ -699,7 +699,7 @@ static int nvme_tcp_recv_data(struct nvme_tcp_queue
*queue, struct sk_buff *skb,
struct nvme_tcp_request *req;
struct request *rq;
- rq = blk_mq_tag_to_rq(nvme_tcp_tagset(queue), pdu->command_id);
+ rq = nvme_cid_to_rq(nvme_tcp_tagset(queue), pdu->command_id);
req = blk_mq_rq_to_pdu(rq);
while (true) {
@@ -794,8 +794,8 @@ static int nvme_tcp_recv_ddgst(struct nvme_tcp_queue
*queue,
}
if (pdu->hdr.flags & NVME_TCP_F_DATA_SUCCESS) {
- struct request *rq =
blk_mq_tag_to_rq(nvme_tcp_tagset(queue),
- pdu->command_id);
+ struct request *rq = nvme_cid_to_rq(nvme_tcp_tagset(queue),
+ pdu->command_id);
nvme_tcp_end_request(rq, NVME_SC_SUCCESS);
queue->nr_cqe++;
diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c
index 1b89a6bb819a..9f1f5d572960 100644
--- a/drivers/nvme/target/loop.c
+++ b/drivers/nvme/target/loop.c
@@ -107,10 +107,10 @@ static void nvme_loop_queue_response(struct
nvmet_req *req)
} else {
struct request *rq;
- rq = blk_mq_tag_to_rq(nvme_loop_tagset(queue),
cqe->command_id);
+ rq = nvme_find_rq(nvme_loop_tagset(queue), cqe->command_id);
if (!rq) {
dev_err(queue->ctrl->ctrl.device,
- "tag 0x%x on queue %d not found\n",
+ "got bad command_id %#x on queue %d\n",
cqe->command_id,
nvme_loop_queue_idx(queue));
return;
}
--
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