Merge tag 'block-6.15-20250403' of git://git.kernel.dk/linux

Pull more block updates from Jens Axboe:

- NVMe pull request via Keith:
- PCI endpoint target cleanup (Damien)
- Early import for uring_cmd fixed buffer (Caleb)
- Multipath documentation and notification improvements (John)
- Invalid pci sq doorbell write fix (Maurizio)

- Queue init locking fix

- Remove dead nsegs parameter from blk_mq_get_new_requests()

* tag 'block-6.15-20250403' of git://git.kernel.dk/linux:
block: don't grab elevator lock during queue initialization
nvme-pci: skip nvme_write_sq_db on empty rqlist
nvme-multipath: change the NVME_MULTIPATH config option
nvme: update the multipath warning in nvme_init_ns_head
nvme/ioctl: move fixed buffer lookup to nvme_uring_cmd_io()
nvme/ioctl: move blk_mq_free_request() out of nvme_map_user_request()
nvme/ioctl: don't warn on vectorized uring_cmd with fixed buffer
nvmet: pci-epf: Keep completion queues mapped
block: remove unused nseg parameter

block/blk-mq.c

···
 
 static struct request *blk_mq_get_new_requests(struct request_queue *q,
 					       struct blk_plug *plug,
-					       struct bio *bio,
-					       unsigned int nsegs)
+					       struct bio *bio)
 {
 	struct blk_mq_alloc_data data = {
 		.q		= q,
···
 	if (rq) {
 		blk_mq_use_cached_rq(rq, plug, bio);
 	} else {
-		rq = blk_mq_get_new_requests(q, plug, bio, nr_segs);
+		rq = blk_mq_get_new_requests(q, plug, bio);
 		if (unlikely(!rq)) {
 			if (bio->bi_opf & REQ_NOWAIT)
 				bio_wouldblock_error(bio);
···
 	return NULL;
 }
 
-static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
-						struct request_queue *q)
+static void __blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
+				     struct request_queue *q)
 {
 	struct blk_mq_hw_ctx *hctx;
 	unsigned long i, j;
 
-	/* protect against switching io scheduler  */
-	mutex_lock(&q->elevator_lock);
 	for (i = 0; i < set->nr_hw_queues; i++) {
 		int old_node;
 		int node = blk_mq_get_hctx_node(set, i);
···
 
 	xa_for_each_start(&q->hctx_table, j, hctx, j)
 		blk_mq_exit_hctx(q, set, hctx, j);
-	mutex_unlock(&q->elevator_lock);
+}
+
+static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
+				   struct request_queue *q, bool lock)
+{
+	if (lock) {
+		/* protect against switching io scheduler  */
+		mutex_lock(&q->elevator_lock);
+		__blk_mq_realloc_hw_ctxs(set, q);
+		mutex_unlock(&q->elevator_lock);
+	} else {
+		__blk_mq_realloc_hw_ctxs(set, q);
+	}
 
 	/* unregister cpuhp callbacks for exited hctxs */
 	blk_mq_remove_hw_queues_cpuhp(q);
···
 
 	xa_init(&q->hctx_table);
 
-	blk_mq_realloc_hw_ctxs(set, q);
+	blk_mq_realloc_hw_ctxs(set, q, false);
 	if (!q->nr_hw_queues)
 		goto err_hctxs;
 
···
 fallback:
 	blk_mq_update_queue_map(set);
 	list_for_each_entry(q, &set->tag_list, tag_set_list) {
-		blk_mq_realloc_hw_ctxs(set, q);
+		blk_mq_realloc_hw_ctxs(set, q, true);
 
 		if (q->nr_hw_queues != set->nr_hw_queues) {
 			int i = prev_nr_hw_queues;

drivers/nvme/host/Kconfig

···
 	bool "NVMe multipath support"
 	depends on NVME_CORE
 	help
-	   This option enables support for multipath access to NVMe
-	   subsystems.  If this option is enabled only a single
-	   /dev/nvmeXnY device will show up for each NVMe namespace,
-	   even if it is accessible through multiple controllers.
+	  This option controls support for multipath access to NVMe
+	  subsystems. If this option is enabled support for NVMe multipath
+	  access is included in the kernel. If this option is disabled support
+	  for NVMe multipath access is excluded from the kernel. When this
+	  option is disabled each controller/namespace receives its
+	  own /dev/nvmeXnY device entry and NVMe multipath access is
+	  not supported.
+
+	  If unsure, say Y.
 
 config NVME_VERBOSE_ERRORS
 	bool "NVMe verbose error reporting"

drivers/nvme/host/core.c

···
 				"Found shared namespace %d, but multipathing not supported.\n",
 				info->nsid);
 			dev_warn_once(ctrl->device,
-				"Support for shared namespaces without CONFIG_NVME_MULTIPATH is deprecated and will be removed in Linux 6.0.\n");
+				"Shared namespace support requires core_nvme.multipath=Y.\n");
 		}
 	}
 

drivers/nvme/host/ioctl.c

···
 
 static int nvme_map_user_request(struct request *req, u64 ubuffer,
 		unsigned bufflen, void __user *meta_buffer, unsigned meta_len,
-		struct io_uring_cmd *ioucmd, unsigned int flags,
-		unsigned int iou_issue_flags)
+		struct iov_iter *iter, unsigned int flags)
 {
 	struct request_queue *q = req->q;
 	struct nvme_ns *ns = q->queuedata;
···
 	if (!nvme_ctrl_sgl_supported(ctrl))
 		dev_warn_once(ctrl->device, "using unchecked data buffer\n");
 	if (has_metadata) {
-		if (!supports_metadata) {
-			ret = -EINVAL;
-			goto out;
-		}
+		if (!supports_metadata)
+			return -EINVAL;
+
 		if (!nvme_ctrl_meta_sgl_supported(ctrl))
 			dev_warn_once(ctrl->device,
 				      "using unchecked metadata buffer\n");
 	}
 
-	if (ioucmd && (ioucmd->flags & IORING_URING_CMD_FIXED)) {
-		struct iov_iter iter;
-
-		/* fixedbufs is only for non-vectored io */
-		if (WARN_ON_ONCE(flags & NVME_IOCTL_VEC)) {
-			ret = -EINVAL;
-			goto out;
-		}
-		ret = io_uring_cmd_import_fixed(ubuffer, bufflen,
-				rq_data_dir(req), &iter, ioucmd,
-				iou_issue_flags);
-		if (ret < 0)
-			goto out;
-		ret = blk_rq_map_user_iov(q, req, NULL, &iter, GFP_KERNEL);
-	} else {
+	if (iter)
+		ret = blk_rq_map_user_iov(q, req, NULL, iter, GFP_KERNEL);
+	else
 		ret = blk_rq_map_user_io(req, NULL, nvme_to_user_ptr(ubuffer),
 				bufflen, GFP_KERNEL, flags & NVME_IOCTL_VEC, 0,
 				0, rq_data_dir(req));
-	}
 
 	if (ret)
-		goto out;
+		return ret;
 
 	bio = req->bio;
 	if (bdev)
···
 out_unmap:
 	if (bio)
 		blk_rq_unmap_user(bio);
-out:
-	blk_mq_free_request(req);
 	return ret;
 }
 
···
 	req->timeout = timeout;
 	if (ubuffer && bufflen) {
 		ret = nvme_map_user_request(req, ubuffer, bufflen, meta_buffer,
-				meta_len, NULL, flags, 0);
+				meta_len, NULL, flags);
 		if (ret)
-			return ret;
+			goto out_free_req;
 	}
 
 	bio = req->bio;
···
 
 	if (effects)
 		nvme_passthru_end(ctrl, ns, effects, cmd, ret);
+	return ret;
 
+out_free_req:
+	blk_mq_free_request(req);
 	return ret;
 }
 
···
 	struct request_queue *q = ns ? ns->queue : ctrl->admin_q;
 	struct nvme_uring_data d;
 	struct nvme_command c;
+	struct iov_iter iter;
+	struct iov_iter *map_iter = NULL;
 	struct request *req;
 	blk_opf_t rq_flags = REQ_ALLOC_CACHE;
 	blk_mq_req_flags_t blk_flags = 0;
···
 	d.metadata_len = READ_ONCE(cmd->metadata_len);
 	d.timeout_ms = READ_ONCE(cmd->timeout_ms);
 
+	if (d.data_len && (ioucmd->flags & IORING_URING_CMD_FIXED)) {
+		/* fixedbufs is only for non-vectored io */
+		if (vec)
+			return -EINVAL;
+
+		ret = io_uring_cmd_import_fixed(d.addr, d.data_len,
+			nvme_is_write(&c) ? WRITE : READ, &iter, ioucmd,
+			issue_flags);
+		if (ret < 0)
+			return ret;
+
+		map_iter = &iter;
+	}
+
 	if (issue_flags & IO_URING_F_NONBLOCK) {
 		rq_flags |= REQ_NOWAIT;
 		blk_flags = BLK_MQ_REQ_NOWAIT;
···
 	req->timeout = d.timeout_ms ? msecs_to_jiffies(d.timeout_ms) : 0;
 
 	if (d.data_len) {
-		ret = nvme_map_user_request(req, d.addr,
-			d.data_len, nvme_to_user_ptr(d.metadata),
-			d.metadata_len, ioucmd, vec, issue_flags);
+		ret = nvme_map_user_request(req, d.addr, d.data_len,
+			nvme_to_user_ptr(d.metadata), d.metadata_len,
+			map_iter, vec);
 		if (ret)
-			return ret;
+			goto out_free_req;
 	}
 
 	/* to free bio on completion, as req->bio will be null at that time */
···
 	req->end_io = nvme_uring_cmd_end_io;
 	blk_execute_rq_nowait(req, false);
 	return -EIOCBQUEUED;
+
+out_free_req:
+	blk_mq_free_request(req);
+	return ret;
 }
 
 static bool is_ctrl_ioctl(unsigned int cmd)

drivers/nvme/host/pci.c

···
 {
 	struct request *req;
 
+	if (rq_list_empty(rqlist))
+		return;
+
 	spin_lock(&nvmeq->sq_lock);
 	while ((req = rq_list_pop(rqlist))) {
 		struct nvme_iod *iod = blk_mq_rq_to_pdu(req);

drivers/nvme/target/pci-epf.c

···
 	struct nvmet_pci_epf_ctrl *ctrl = tctrl->drvdata;
 	struct nvmet_pci_epf_queue *cq = &ctrl->cq[cqid];
 	u16 status;
+	int ret;
 
 	if (test_bit(NVMET_PCI_EPF_Q_LIVE, &cq->flags))
 		return NVME_SC_QID_INVALID | NVME_STATUS_DNR;
···
 	if (status != NVME_SC_SUCCESS)
 		goto err;
 
+	/*
+	 * Map the CQ PCI address space and since PCI endpoint controllers may
+	 * return a partial mapping, check that the mapping is large enough.
+	 */
+	ret = nvmet_pci_epf_mem_map(ctrl->nvme_epf, cq->pci_addr, cq->pci_size,
+				    &cq->pci_map);
+	if (ret) {
+		dev_err(ctrl->dev, "Failed to map CQ %u (err=%d)\n",
+			cq->qid, ret);
+		goto err_internal;
+	}
+
+	if (cq->pci_map.pci_size < cq->pci_size) {
+		dev_err(ctrl->dev, "Invalid partial mapping of queue %u\n",
+			cq->qid);
+		goto err_unmap_queue;
+	}
+
 	set_bit(NVMET_PCI_EPF_Q_LIVE, &cq->flags);
 
 	dev_dbg(ctrl->dev, "CQ[%u]: %u entries of %zu B, IRQ vector %u\n",
···
 
 	return NVME_SC_SUCCESS;
 
+err_unmap_queue:
+	nvmet_pci_epf_mem_unmap(ctrl->nvme_epf, &cq->pci_map);
+err_internal:
+	status = NVME_SC_INTERNAL | NVME_STATUS_DNR;
 err:
 	if (test_and_clear_bit(NVMET_PCI_EPF_Q_IRQ_ENABLED, &cq->flags))
 		nvmet_pci_epf_remove_irq_vector(ctrl, cq->vector);
···
 	cancel_delayed_work_sync(&cq->work);
 	nvmet_pci_epf_drain_queue(cq);
 	nvmet_pci_epf_remove_irq_vector(ctrl, cq->vector);
+	nvmet_pci_epf_mem_unmap(ctrl->nvme_epf, &cq->pci_map);
 
 	return NVME_SC_SUCCESS;
 }
···
 	ctrl->cq = NULL;
 }
 
-static int nvmet_pci_epf_map_queue(struct nvmet_pci_epf_ctrl *ctrl,
-				   struct nvmet_pci_epf_queue *queue)
-{
-	struct nvmet_pci_epf *nvme_epf = ctrl->nvme_epf;
-	int ret;
-
-	ret = nvmet_pci_epf_mem_map(nvme_epf, queue->pci_addr,
-				      queue->pci_size, &queue->pci_map);
-	if (ret) {
-		dev_err(ctrl->dev, "Failed to map queue %u (err=%d)\n",
-			queue->qid, ret);
-		return ret;
-	}
-
-	if (queue->pci_map.pci_size < queue->pci_size) {
-		dev_err(ctrl->dev, "Invalid partial mapping of queue %u\n",
-			queue->qid);
-		nvmet_pci_epf_mem_unmap(nvme_epf, &queue->pci_map);
-		return -ENOMEM;
-	}
-
-	return 0;
-}
-
-static inline void nvmet_pci_epf_unmap_queue(struct nvmet_pci_epf_ctrl *ctrl,
-					     struct nvmet_pci_epf_queue *queue)
-{
-	nvmet_pci_epf_mem_unmap(ctrl->nvme_epf, &queue->pci_map);
-}
-
 static void nvmet_pci_epf_exec_iod_work(struct work_struct *work)
 {
 	struct nvmet_pci_epf_iod *iod =
···
 	struct nvme_completion *cqe;
 	struct nvmet_pci_epf_iod *iod;
 	unsigned long flags;
-	int ret, n = 0;
-
-	ret = nvmet_pci_epf_map_queue(ctrl, cq);
-	if (ret)
-		goto again;
+	int ret = 0, n = 0;
 
 	while (test_bit(NVMET_PCI_EPF_Q_LIVE, &cq->flags) && ctrl->link_up) {
 
···
 		n++;
 	}
 
-	nvmet_pci_epf_unmap_queue(ctrl, cq);
-
 	/*
 	 * We do not support precise IRQ coalescing time (100ns units as per
 	 * NVMe specifications). So if we have posted completion entries without
···
 	if (n)
 		nvmet_pci_epf_raise_irq(ctrl, cq, true);
 
-again:
 	if (ret < 0)
 		queue_delayed_work(system_highpri_wq, &cq->work,
 				   NVMET_PCI_EPF_CQ_RETRY_INTERVAL);