Merge branch 'nvme-5.1' of git://git.infradead.org/nvme into for-linus

Pull NVMe fixes from Christoph:

"Two nvme fixes for 5.1 - fixing the initial CSN for nvme-fc, and handle
 log page offsets properly in the target."

* 'nvme-5.1' of git://git.infradead.org/nvme:
  nvmet: fix discover log page when offsets are used
  nvme-fc: correct csn initialization and increments on error

Author: axboe

drivers/nvme/host/fc.c

@@ -1845,7 +1845,7 @@ nvme_fc_init_queue(struct nvme_fc_ctrl *ctrl, int idx)
 	memset(queue, 0, sizeof(*queue));
 	queue->ctrl = ctrl;
 	queue->qnum = idx;
-	atomic_set(&queue->csn, 1);
+	atomic_set(&queue->csn, 0);
 	queue->dev = ctrl->dev;
 
 	if (idx > 0)
@@ -1887,7 +1887,7 @@ nvme_fc_free_queue(struct nvme_fc_queue *queue)
 	 */
 
 	queue->connection_id = 0;
-	atomic_set(&queue->csn, 1);
+	atomic_set(&queue->csn, 0);
 }
 
 static void
@@ -2183,7 +2183,6 @@ nvme_fc_start_fcp_op(struct nvme_fc_ctrl *ctrl, struct nvme_fc_queue *queue,
 {
 	struct nvme_fc_cmd_iu *cmdiu = &op->cmd_iu;
 	struct nvme_command *sqe = &cmdiu->sqe;
-	u32 csn;
 	int ret, opstate;
 
 	/*
@@ -2198,8 +2197,6 @@ nvme_fc_start_fcp_op(struct nvme_fc_ctrl *ctrl, struct nvme_fc_queue *queue,
 
 	/* format the FC-NVME CMD IU and fcp_req */
 	cmdiu->connection_id = cpu_to_be64(queue->connection_id);
-	csn = atomic_inc_return(&queue->csn);
-	cmdiu->csn = cpu_to_be32(csn);
 	cmdiu->data_len = cpu_to_be32(data_len);
 	switch (io_dir) {
 	case NVMEFC_FCP_WRITE:
@@ -2257,11 +2254,24 @@ nvme_fc_start_fcp_op(struct nvme_fc_ctrl *ctrl, struct nvme_fc_queue *queue,
 	if (!(op->flags & FCOP_FLAGS_AEN))
 		blk_mq_start_request(op->rq);
 
+	cmdiu->csn = cpu_to_be32(atomic_inc_return(&queue->csn));
 	ret = ctrl->lport->ops->fcp_io(&ctrl->lport->localport,
 					&ctrl->rport->remoteport,
 					queue->lldd_handle, &op->fcp_req);
 
 	if (ret) {
+		/*
+		 * If the lld fails to send the command is there an issue with
+		 * the csn value?  If the command that fails is the Connect,
+		 * no - as the connection won't be live.  If it is a command
+		 * post-connect, it's possible a gap in csn may be created.
+		 * Does this matter?  As Linux initiators don't send fused
+		 * commands, no.  The gap would exist, but as there's nothing
+		 * that depends on csn order to be delivered on the target
+		 * side, it shouldn't hurt.  It would be difficult for a
+		 * target to even detect the csn gap as it has no idea when the
+		 * cmd with the csn was supposed to arrive.
+		 */
 		opstate = atomic_xchg(&op->state, FCPOP_STATE_COMPLETE);
 		__nvme_fc_fcpop_chk_teardowns(ctrl, op, opstate);
 

drivers/nvme/target/admin-cmd.c

@@ -24,6 +24,11 @@ u32 nvmet_get_log_page_len(struct nvme_command *cmd)
 	return len;
 }
 
+u64 nvmet_get_log_page_offset(struct nvme_command *cmd)
+{
+	return le64_to_cpu(cmd->get_log_page.lpo);
+}
+
 static void nvmet_execute_get_log_page_noop(struct nvmet_req *req)
 {
 	nvmet_req_complete(req, nvmet_zero_sgl(req, 0, req->data_len));

drivers/nvme/target/discovery.c

@@ -131,54 +131,76 @@ static void nvmet_set_disc_traddr(struct nvmet_req *req, struct nvmet_port *port
 		memcpy(traddr, port->disc_addr.traddr, NVMF_TRADDR_SIZE);
 }
 
+static size_t discovery_log_entries(struct nvmet_req *req)
+{
+	struct nvmet_ctrl *ctrl = req->sq->ctrl;
+	struct nvmet_subsys_link *p;
+	struct nvmet_port *r;
+	size_t entries = 0;
+
+	list_for_each_entry(p, &req->port->subsystems, entry) {
+		if (!nvmet_host_allowed(p->subsys, ctrl->hostnqn))
+			continue;
+		entries++;
+	}
+	list_for_each_entry(r, &req->port->referrals, entry)
+		entries++;
+	return entries;
+}
+
 static void nvmet_execute_get_disc_log_page(struct nvmet_req *req)
 {
 	const int entry_size = sizeof(struct nvmf_disc_rsp_page_entry);
 	struct nvmet_ctrl *ctrl = req->sq->ctrl;
 	struct nvmf_disc_rsp_page_hdr *hdr;
+	u64 offset = nvmet_get_log_page_offset(req->cmd);
 	size_t data_len = nvmet_get_log_page_len(req->cmd);
-	size_t alloc_len = max(data_len, sizeof(*hdr));
-	int residual_len = data_len - sizeof(*hdr);
+	size_t alloc_len;
 	struct nvmet_subsys_link *p;
 	struct nvmet_port *r;
 	u32 numrec = 0;
 	u16 status = 0;
+	void *buffer;
+
+	/* Spec requires dword aligned offsets */
+	if (offset & 0x3) {
+		status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
+		goto out;
+	}
 
 	/*
 	 * Make sure we're passing at least a buffer of response header size.
 	 * If host provided data len is less than the header size, only the
 	 * number of bytes requested by host will be sent to host.
 	 */
-	hdr = kzalloc(alloc_len, GFP_KERNEL);
-	if (!hdr) {
+	down_read(&nvmet_config_sem);
+	alloc_len = sizeof(*hdr) + entry_size * discovery_log_entries(req);
+	buffer = kzalloc(alloc_len, GFP_KERNEL);
+	if (!buffer) {
+		up_read(&nvmet_config_sem);
 		status = NVME_SC_INTERNAL;
 		goto out;
 	}
 
-	down_read(&nvmet_config_sem);
+	hdr = buffer;
 	list_for_each_entry(p, &req->port->subsystems, entry) {
+		char traddr[NVMF_TRADDR_SIZE];
+
 		if (!nvmet_host_allowed(p->subsys, ctrl->hostnqn))
 			continue;
-		if (residual_len >= entry_size) {
-			char traddr[NVMF_TRADDR_SIZE];
-
-			nvmet_set_disc_traddr(req, req->port, traddr);
-			nvmet_format_discovery_entry(hdr, req->port,
-					p->subsys->subsysnqn, traddr,
-					NVME_NQN_NVME, numrec);
-			residual_len -= entry_size;
-		}
+
+		nvmet_set_disc_traddr(req, req->port, traddr);
+		nvmet_format_discovery_entry(hdr, req->port,
+				p->subsys->subsysnqn, traddr,
+				NVME_NQN_NVME, numrec);
 		numrec++;
 	}
 
 	list_for_each_entry(r, &req->port->referrals, entry) {
-		if (residual_len >= entry_size) {
-			nvmet_format_discovery_entry(hdr, r,
-					NVME_DISC_SUBSYS_NAME,
-					r->disc_addr.traddr,
-					NVME_NQN_DISC, numrec);
-			residual_len -= entry_size;
-		}
+		nvmet_format_discovery_entry(hdr, r,
+				NVME_DISC_SUBSYS_NAME,
+				r->disc_addr.traddr,
+				NVME_NQN_DISC, numrec);
 		numrec++;
 	}
 
@@ -190,8 +212,8 @@ static void nvmet_execute_get_disc_log_page(struct nvmet_req *req)
 
 	up_read(&nvmet_config_sem);
 
-	status = nvmet_copy_to_sgl(req, 0, hdr, data_len);
-	kfree(hdr);
+	status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len);
+	kfree(buffer);
 out:
 	nvmet_req_complete(req, status);
 }

drivers/nvme/target/nvmet.h

@@ -428,6 +428,7 @@ u16 nvmet_copy_from_sgl(struct nvmet_req *req, off_t off, void *buf,
 u16 nvmet_zero_sgl(struct nvmet_req *req, off_t off, size_t len);
 
 u32 nvmet_get_log_page_len(struct nvme_command *cmd);
+u64 nvmet_get_log_page_offset(struct nvme_command *cmd);
 
 extern struct list_head *nvmet_ports;
 void nvmet_port_disc_changed(struct nvmet_port *port,

include/linux/nvme.h

@@ -967,8 +967,13 @@ struct nvme_get_log_page_command {
 	__le16			numdl;
 	__le16			numdu;
 	__u16			rsvd11;
-	__le32			lpol;
-	__le32			lpou;
+	union {
+		struct {
+			__le32 lpol;
+			__le32 lpou;
+		};
+		__le64 lpo;
+	};
 	__u32			rsvd14[2];
 };