From: Sagi Grimberg sagi@grimberg.me
[ Upstream commit e7006de6c23803799be000a5dcce4d916a36541a ]
We cannot detect a (perhaps buggy) controller that is sending us a completion for a request that was already completed (for example sending a completion twice), this phenomenon was seen in the wild a few times.
So to protect against this, we use the upper 4 msbits of the nvme sqe command_id to use as a 4-bit generation counter and verify it matches the existing request generation that is incrementing on every execution.
The 16-bit command_id structure now is constructed by: | xxxx | xxxxxxxxxxxx | gen request tag
This means that we are giving up some possible queue depth as 12 bits allow for a maximum queue depth of 4095 instead of 65536, however we never create such long queues anyways so no real harm done.
Suggested-by: Keith Busch kbusch@kernel.org Signed-off-by: Sagi Grimberg sagi@grimberg.me Acked-by: Keith Busch kbusch@kernel.org Reviewed-by: Hannes Reinecke hare@suse.de Reviewed-by: Daniel Wagner dwagner@suse.de Tested-by: Daniel Wagner dwagner@suse.de Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/core.c | 3 ++- drivers/nvme/host/nvme.h | 47 +++++++++++++++++++++++++++++++++++++- drivers/nvme/host/pci.c | 2 +- drivers/nvme/host/rdma.c | 4 ++-- drivers/nvme/host/tcp.c | 26 ++++++++++----------- drivers/nvme/target/loop.c | 4 ++-- 6 files changed, 66 insertions(+), 20 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index ff5a16b17133..5a9b2f1b1418 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -878,7 +878,8 @@ blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req, return BLK_STS_IOERR; }
- cmd->common.command_id = req->tag; + nvme_req(req)->genctr++; + 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 3cb3c82061d7..8c735c55c15b 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -153,6 +153,7 @@ enum nvme_quirks { struct nvme_request { struct nvme_command *cmd; union nvme_result result; + u8 genctr; u8 retries; u8 flags; u16 status; @@ -469,6 +470,49 @@ 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_genctr_mask(gen) (gen & 0xf) +#define nvme_cid_install_genctr(gen) (nvme_genctr_mask(gen) << 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_genctr_mask(nvme_req(rq)->genctr) != genctr)) { + dev_err(nvme_req(rq)->ctrl->device, + "request %#x genctr mismatch (got %#x expected %#x)\n", + tag, genctr, nvme_genctr_mask(nvme_req(rq)->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); @@ -566,7 +610,8 @@ 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 fb48a88d1acb..09767a805492 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -1012,7 +1012,7 @@ 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 e6d58402b829..3d225d7fa896 100644 --- a/drivers/nvme/host/rdma.c +++ b/drivers/nvme/host/rdma.c @@ -1738,10 +1738,10 @@ 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 ab03da094db7..f0dae80c2e8d 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -484,11 +484,11 @@ 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; } @@ -505,11 +505,11 @@ 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; }
@@ -603,7 +603,7 @@ 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; @@ -616,11 +616,11 @@ 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); @@ -700,7 +700,7 @@ static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb, { struct nvme_tcp_data_pdu *pdu = (void *)queue->pdu; struct request *rq = - blk_mq_tag_to_rq(nvme_tcp_tagset(queue), pdu->command_id); + nvme_cid_to_rq(nvme_tcp_tagset(queue), pdu->command_id); struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
while (true) { @@ -793,8 +793,8 @@ 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 16d71cc5a50e..ff3258c3eb8b 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; }