Merge tag 'block-5.15-2021-09-11' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - NVMe pull request from Christoph:
     - fix nvmet command set reporting for passthrough controllers (Adam Manzanares)
     - update a MAINTAINERS email address (Chaitanya Kulkarni)
     - set QUEUE_FLAG_NOWAIT for nvme-multipth (me)
     - handle errors from add_disk() (Luis Chamberlain)
     - update the keep alive interval when kato is modified (Tatsuya Sasaki)
     - fix a buffer overrun in nvmet_subsys_attr_serial (Hannes Reinecke)
     - do not reset transport on data digest errors in nvme-tcp (Daniel Wagner)
     - only call synchronize_srcu when clearing current path (Daniel Wagner)
     - revalidate paths during rescan (Hannes Reinecke)

 - Split out the fs/block_dev into block/fops.c and block/bdev.c, which
   has been long overdue. Do this now before -rc1, to avoid annoying
   conflicts due to this (Christoph)

 - blk-throtl use-after-free fix (Li)

 - Improve plug depth for multi-device plugs, greatly increasing md
   resync performance (Song)

 - blkdev_show() locking fix (Tetsuo)

 - n64cart error check fix (Yang)

* tag 'block-5.15-2021-09-11' of git://git.kernel.dk/linux-block:
  n64cart: fix return value check in n64cart_probe()
  blk-mq: allow 4x BLK_MAX_REQUEST_COUNT at blk_plug for multiple_queues
  block: move fs/block_dev.c to block/bdev.c
  block: split out operations on block special files
  blk-throttle: fix UAF by deleteing timer in blk_throtl_exit()
  block: genhd: don't call blkdev_show() with major_names_lock held
  nvme: update MAINTAINERS email address
  nvme: add error handling support for add_disk()
  nvme: only call synchronize_srcu when clearing current path
  nvme: update keep alive interval when kato is modified
  nvme-tcp: Do not reset transport on data digest errors
  nvmet: fixup buffer overrun in nvmet_subsys_attr_serial()
  nvmet: return bool from nvmet_passthru_ctrl and nvmet_is_passthru_req
  nvmet: looks at the passthrough controller when initializing CAP
  nvme: move nvme_multi_css into nvme.h
  nvme-multipath: revalidate paths during rescan
  nvme-multipath: set QUEUE_FLAG_NOWAIT

Documentation/core-api/kernel-api.rst

@@ -315,6 +315,9 @@ Block Devices
 .. kernel-doc:: block/genhd.c
    :export:
 
+.. kernel-doc:: block/bdev.c
+   :export:
+
 Char devices
 ============
 

Documentation/filesystems/api-summary.rst

@@ -71,9 +71,6 @@ Other Functions
 .. kernel-doc:: fs/fs-writeback.c
    :export:
 
-.. kernel-doc:: fs/block_dev.c
-   :export:
-
 .. kernel-doc:: fs/anon_inodes.c
    :export:
 

MAINTAINERS

@@ -3313,7 +3313,6 @@ S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git
 F:	block/
 F:	drivers/block/
-F:	fs/block_dev.c
 F:	include/linux/blk*
 F:	kernel/trace/blktrace.c
 F:	lib/sbitmap.c
@@ -13409,7 +13408,7 @@ F:	include/linux/nvme-fc.h
 NVM EXPRESS TARGET DRIVER
 M:	Christoph Hellwig <hch@lst.de>
 M:	Sagi Grimberg <sagi@grimberg.me>
-M:	Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
+M:	Chaitanya Kulkarni <kch@nvidia.com>
 L:	linux-nvme@lists.infradead.org
 S:	Supported
 W:	http://git.infradead.org/nvme.git

block/Makefile

@@ -3,7 +3,7 @@
 # Makefile for the kernel block layer
 #
 
-obj-$(CONFIG_BLOCK) := bio.o elevator.o blk-core.o blk-sysfs.o \
+obj-$(CONFIG_BLOCK) := bdev.o fops.o bio.o elevator.o blk-core.o blk-sysfs.o \
 			blk-flush.o blk-settings.o blk-ioc.o blk-map.o \
 			blk-exec.o blk-merge.o blk-timeout.o \
 			blk-lib.o blk-mq.o blk-mq-tag.o blk-stat.o \

block/blk-mq.c

@@ -2135,6 +2135,18 @@ static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq)
 	}
 }
 
+/*
+ * Allow 4x BLK_MAX_REQUEST_COUNT requests on plug queue for multiple
+ * queues. This is important for md arrays to benefit from merging
+ * requests.
+ */
+static inline unsigned short blk_plug_max_rq_count(struct blk_plug *plug)
+{
+	if (plug->multiple_queues)
+		return BLK_MAX_REQUEST_COUNT * 4;
+	return BLK_MAX_REQUEST_COUNT;
+}
+
 /**
  * blk_mq_submit_bio - Create and send a request to block device.
  * @bio: Bio pointer.
@@ -2231,7 +2243,7 @@ blk_qc_t blk_mq_submit_bio(struct bio *bio)
 		else
 			last = list_entry_rq(plug->mq_list.prev);
 
-		if (request_count >= BLK_MAX_REQUEST_COUNT || (last &&
+		if (request_count >= blk_plug_max_rq_count(plug) || (last &&
 		    blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) {
 			blk_flush_plug_list(plug, false);
 			trace_block_plug(q);

block/blk-throttle.c

@@ -2458,6 +2458,7 @@ int blk_throtl_init(struct request_queue *q)
 void blk_throtl_exit(struct request_queue *q)
 {
 	BUG_ON(!q->td);
+	del_timer_sync(&q->td->service_queue.pending_timer);
 	throtl_shutdown_wq(q);
 	blkcg_deactivate_policy(q, &blkcg_policy_throtl);
 	free_percpu(q->td->latency_buckets[READ]);

block/blk.h

@@ -373,4 +373,6 @@ static inline void bio_clear_hipri(struct bio *bio)
 	bio->bi_opf &= ~REQ_HIPRI;
 }
 
+extern const struct address_space_operations def_blk_aops;
+
 #endif /* BLK_INTERNAL_H */

block/genhd.c

@@ -183,6 +183,7 @@ static struct blk_major_name {
 	void (*probe)(dev_t devt);
 } *major_names[BLKDEV_MAJOR_HASH_SIZE];
 static DEFINE_MUTEX(major_names_lock);
+static DEFINE_SPINLOCK(major_names_spinlock);
 
 /* index in the above - for now: assume no multimajor ranges */
 static inline int major_to_index(unsigned major)
@@ -195,11 +196,11 @@ void blkdev_show(struct seq_file *seqf, off_t offset)
 {
 	struct blk_major_name *dp;
 
-	mutex_lock(&major_names_lock);
+	spin_lock(&major_names_spinlock);
 	for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next)
 		if (dp->major == offset)
 			seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
-	mutex_unlock(&major_names_lock);
+	spin_unlock(&major_names_spinlock);
 }
 #endif /* CONFIG_PROC_FS */
 
@@ -271,6 +272,7 @@ int __register_blkdev(unsigned int major, const char *name,
 	p->next = NULL;
 	index = major_to_index(major);
 
+	spin_lock(&major_names_spinlock);
 	for (n = &major_names[index]; *n; n = &(*n)->next) {
 		if ((*n)->major == major)
 			break;
@@ -279,6 +281,7 @@ int __register_blkdev(unsigned int major, const char *name,
 		*n = p;
 	else
 		ret = -EBUSY;
+	spin_unlock(&major_names_spinlock);
 
 	if (ret < 0) {
 		printk("register_blkdev: cannot get major %u for %s\n",
@@ -298,6 +301,7 @@ void unregister_blkdev(unsigned int major, const char *name)
 	int index = major_to_index(major);
 
 	mutex_lock(&major_names_lock);
+	spin_lock(&major_names_spinlock);
 	for (n = &major_names[index]; *n; n = &(*n)->next)
 		if ((*n)->major == major)
 			break;
@@ -307,6 +311,7 @@ void unregister_blkdev(unsigned int major, const char *name)
 		p = *n;
 		*n = p->next;
 	}
+	spin_unlock(&major_names_spinlock);
 	mutex_unlock(&major_names_lock);
 	kfree(p);
 }

drivers/block/n64cart.c

@@ -129,8 +129,8 @@ static int __init n64cart_probe(struct platform_device *pdev)
 	}
 
 	reg_base = devm_platform_ioremap_resource(pdev, 0);
-	if (!reg_base)
-		return -EINVAL;
+	if (IS_ERR(reg_base))
+		return PTR_ERR(reg_base);
 
 	disk = blk_alloc_disk(NUMA_NO_NODE);
 	if (!disk)

drivers/nvme/host/core.c

@@ -116,6 +116,8 @@ static struct class *nvme_ns_chr_class;
 static void nvme_put_subsystem(struct nvme_subsystem *subsys);
 static void nvme_remove_invalid_namespaces(struct nvme_ctrl *ctrl,
 					   unsigned nsid);
+static void nvme_update_keep_alive(struct nvme_ctrl *ctrl,
+				   struct nvme_command *cmd);
 
 /*
  * Prepare a queue for teardown.
@@ -1152,7 +1154,8 @@ static u32 nvme_passthru_start(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
 	return effects;
 }
 
-static void nvme_passthru_end(struct nvme_ctrl *ctrl, u32 effects)
+static void nvme_passthru_end(struct nvme_ctrl *ctrl, u32 effects,
+			      struct nvme_command *cmd, int status)
 {
 	if (effects & NVME_CMD_EFFECTS_CSE_MASK) {
 		nvme_unfreeze(ctrl);
@@ -1167,6 +1170,26 @@ static void nvme_passthru_end(struct nvme_ctrl *ctrl, u32 effects)
 		nvme_queue_scan(ctrl);
 		flush_work(&ctrl->scan_work);
 	}
+
+	switch (cmd->common.opcode) {
+	case nvme_admin_set_features:
+		switch (le32_to_cpu(cmd->common.cdw10) & 0xFF) {
+		case NVME_FEAT_KATO:
+			/*
+			 * Keep alive commands interval on the host should be
+			 * updated when KATO is modified by Set Features
+			 * commands.
+			 */
+			if (!status)
+				nvme_update_keep_alive(ctrl, cmd);
+			break;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
 }
 
 int nvme_execute_passthru_rq(struct request *rq)
@@ -1181,7 +1204,7 @@ int nvme_execute_passthru_rq(struct request *rq)
 	effects = nvme_passthru_start(ctrl, ns, cmd->common.opcode);
 	ret = nvme_execute_rq(disk, rq, false);
 	if (effects) /* nothing to be done for zero cmd effects */
-		nvme_passthru_end(ctrl, effects);
+		nvme_passthru_end(ctrl, effects, cmd, ret);
 
 	return ret;
 }
@@ -1269,6 +1292,21 @@ void nvme_stop_keep_alive(struct nvme_ctrl *ctrl)
 }
 EXPORT_SYMBOL_GPL(nvme_stop_keep_alive);
 
+static void nvme_update_keep_alive(struct nvme_ctrl *ctrl,
+				   struct nvme_command *cmd)
+{
+	unsigned int new_kato =
+		DIV_ROUND_UP(le32_to_cpu(cmd->common.cdw11), 1000);
+
+	dev_info(ctrl->device,
+		 "keep alive interval updated from %u ms to %u ms\n",
+		 ctrl->kato * 1000 / 2, new_kato * 1000 / 2);
+
+	nvme_stop_keep_alive(ctrl);
+	ctrl->kato = new_kato;
+	nvme_start_keep_alive(ctrl);
+}
+
 /*
  * In NVMe 1.0 the CNS field was just a binary controller or namespace
  * flag, thus sending any new CNS opcodes has a big chance of not working.
@@ -1302,11 +1340,6 @@ static int nvme_identify_ctrl(struct nvme_ctrl *dev, struct nvme_id_ctrl **id)
 	return error;
 }
 
-static bool nvme_multi_css(struct nvme_ctrl *ctrl)
-{
-	return (ctrl->ctrl_config & NVME_CC_CSS_MASK) == NVME_CC_CSS_CSI;
-}
-
 static int nvme_process_ns_desc(struct nvme_ctrl *ctrl, struct nvme_ns_ids *ids,
 		struct nvme_ns_id_desc *cur, bool *csi_seen)
 {
@@ -1874,6 +1907,7 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
 			goto out_unfreeze;
 	}
 
+	set_bit(NVME_NS_READY, &ns->flags);
 	blk_mq_unfreeze_queue(ns->disk->queue);
 
 	if (blk_queue_is_zoned(ns->queue)) {
@@ -1885,6 +1919,7 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
 	if (nvme_ns_head_multipath(ns->head)) {
 		blk_mq_freeze_queue(ns->head->disk->queue);
 		nvme_update_disk_info(ns->head->disk, ns, id);
+		nvme_mpath_revalidate_paths(ns);
 		blk_stack_limits(&ns->head->disk->queue->limits,
 				 &ns->queue->limits, 0);
 		disk_update_readahead(ns->head->disk);
@@ -3763,7 +3798,9 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
 
 	nvme_get_ctrl(ctrl);
 
-	device_add_disk(ctrl->device, ns->disk, nvme_ns_id_attr_groups);
+	if (device_add_disk(ctrl->device, ns->disk, nvme_ns_id_attr_groups))
+		goto out_cleanup_ns_from_list;
+
 	if (!nvme_ns_head_multipath(ns->head))
 		nvme_add_ns_cdev(ns);
 
@@ -3773,6 +3810,11 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
 
 	return;
 
+ out_cleanup_ns_from_list:
+	nvme_put_ctrl(ctrl);
+	down_write(&ctrl->namespaces_rwsem);
+	list_del_init(&ns->list);
+	up_write(&ctrl->namespaces_rwsem);
  out_unlink_ns:
 	mutex_lock(&ctrl->subsys->lock);
 	list_del_rcu(&ns->siblings);
@@ -3795,6 +3837,7 @@ static void nvme_ns_remove(struct nvme_ns *ns)
 	if (test_and_set_bit(NVME_NS_REMOVING, &ns->flags))
 		return;
 
+	clear_bit(NVME_NS_READY, &ns->flags);
 	set_capacity(ns->disk, 0);
 	nvme_fault_inject_fini(&ns->fault_inject);
 
@@ -3802,9 +3845,12 @@ static void nvme_ns_remove(struct nvme_ns *ns)
 	list_del_rcu(&ns->siblings);
 	mutex_unlock(&ns->ctrl->subsys->lock);
 
-	synchronize_rcu(); /* guarantee not available in head->list */
-	nvme_mpath_clear_current_path(ns);
-	synchronize_srcu(&ns->head->srcu); /* wait for concurrent submissions */
+	/* guarantee not available in head->list */
+	synchronize_rcu();
+
+	/* wait for concurrent submissions */
+	if (nvme_mpath_clear_current_path(ns))
+		synchronize_srcu(&ns->head->srcu);
 
 	if (!nvme_ns_head_multipath(ns->head))
 		nvme_cdev_del(&ns->cdev, &ns->cdev_device);

drivers/nvme/host/multipath.c

@@ -147,6 +147,21 @@ void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl)
 	mutex_unlock(&ctrl->scan_lock);
 }
 
+void nvme_mpath_revalidate_paths(struct nvme_ns *ns)
+{
+	struct nvme_ns_head *head = ns->head;
+	sector_t capacity = get_capacity(head->disk);
+	int node;
+
+	list_for_each_entry_rcu(ns, &head->list, siblings) {
+		if (capacity != get_capacity(ns->disk))
+			clear_bit(NVME_NS_READY, &ns->flags);
+	}
+
+	for_each_node(node)
+		rcu_assign_pointer(head->current_path[node], NULL);
+}
+
 static bool nvme_path_is_disabled(struct nvme_ns *ns)
 {
 	/*
@@ -158,7 +173,7 @@ static bool nvme_path_is_disabled(struct nvme_ns *ns)
 	    ns->ctrl->state != NVME_CTRL_DELETING)
 		return true;
 	if (test_bit(NVME_NS_ANA_PENDING, &ns->flags) ||
-	    test_bit(NVME_NS_REMOVING, &ns->flags))
+	    !test_bit(NVME_NS_READY, &ns->flags))
 		return true;
 	return false;
 }
@@ -465,6 +480,8 @@ int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head)
 			ctrl->subsys->instance, head->instance);
 
 	blk_queue_flag_set(QUEUE_FLAG_NONROT, head->disk->queue);
+	blk_queue_flag_set(QUEUE_FLAG_NOWAIT, head->disk->queue);
+
 	/* set to a default value of 512 until the disk is validated */
 	blk_queue_logical_block_size(head->disk->queue, 512);
 	blk_set_stacking_limits(&head->disk->queue->limits);

drivers/nvme/host/nvme.h

@@ -456,6 +456,7 @@ struct nvme_ns {
 #define NVME_NS_DEAD     	1
 #define NVME_NS_ANA_PENDING	2
 #define NVME_NS_FORCE_RO	3
+#define NVME_NS_READY		4
 
 	struct cdev		cdev;
 	struct device		cdev_device;
@@ -748,6 +749,7 @@ void nvme_mpath_init_ctrl(struct nvme_ctrl *ctrl);
 void nvme_mpath_uninit(struct nvme_ctrl *ctrl);
 void nvme_mpath_stop(struct nvme_ctrl *ctrl);
 bool nvme_mpath_clear_current_path(struct nvme_ns *ns);
+void nvme_mpath_revalidate_paths(struct nvme_ns *ns);
 void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl);
 void nvme_mpath_shutdown_disk(struct nvme_ns_head *head);
 
@@ -795,6 +797,9 @@ static inline bool nvme_mpath_clear_current_path(struct nvme_ns *ns)
 {
 	return false;
 }
+static inline void nvme_mpath_revalidate_paths(struct nvme_ns *ns)
+{
+}
 static inline void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl)
 {
 }
@@ -887,4 +892,9 @@ struct nvme_ctrl *nvme_ctrl_from_file(struct file *file);
 struct nvme_ns *nvme_find_get_ns(struct nvme_ctrl *ctrl, unsigned nsid);
 void nvme_put_ns(struct nvme_ns *ns);
 
+static inline bool nvme_multi_css(struct nvme_ctrl *ctrl)
+{
+	return (ctrl->ctrl_config & NVME_CC_CSS_MASK) == NVME_CC_CSS_CSI;
+}
+
 #endif /* _NVME_H */

drivers/nvme/host/tcp.c

@@ -45,6 +45,7 @@ struct nvme_tcp_request {
 	u32			pdu_len;
 	u32			pdu_sent;
 	u16			ttag;
+	__le16			status;
 	struct list_head	entry;
 	struct llist_node	lentry;
 	__le32			ddgst;
@@ -485,6 +486,7 @@ static void nvme_tcp_error_recovery(struct nvme_ctrl *ctrl)
 static int nvme_tcp_process_nvme_cqe(struct nvme_tcp_queue *queue,
 		struct nvme_completion *cqe)
 {
+	struct nvme_tcp_request *req;
 	struct request *rq;
 
 	rq = nvme_find_rq(nvme_tcp_tagset(queue), cqe->command_id);
@@ -496,7 +498,11 @@ static int nvme_tcp_process_nvme_cqe(struct nvme_tcp_queue *queue,
 		return -EINVAL;
 	}
 
-	if (!nvme_try_complete_req(rq, cqe->status, cqe->result))
+	req = blk_mq_rq_to_pdu(rq);
+	if (req->status == cpu_to_le16(NVME_SC_SUCCESS))
+		req->status = cqe->status;
+
+	if (!nvme_try_complete_req(rq, req->status, cqe->result))
 		nvme_complete_rq(rq);
 	queue->nr_cqe++;
 
@@ -758,7 +764,8 @@ static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb,
 			queue->ddgst_remaining = NVME_TCP_DIGEST_LENGTH;
 		} else {
 			if (pdu->hdr.flags & NVME_TCP_F_DATA_SUCCESS) {
-				nvme_tcp_end_request(rq, NVME_SC_SUCCESS);
+				nvme_tcp_end_request(rq,
+						le16_to_cpu(req->status));
 				queue->nr_cqe++;
 			}
 			nvme_tcp_init_recv_ctx(queue);
@@ -788,18 +795,24 @@ static int nvme_tcp_recv_ddgst(struct nvme_tcp_queue *queue,
 		return 0;
 
 	if (queue->recv_ddgst != queue->exp_ddgst) {
+		struct request *rq = nvme_cid_to_rq(nvme_tcp_tagset(queue),
+					pdu->command_id);
+		struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
+
+		req->status = cpu_to_le16(NVME_SC_DATA_XFER_ERROR);
+
 		dev_err(queue->ctrl->ctrl.device,
 			"data digest error: recv %#x expected %#x\n",
 			le32_to_cpu(queue->recv_ddgst),
 			le32_to_cpu(queue->exp_ddgst));
-		return -EIO;
 	}
 
 	if (pdu->hdr.flags & NVME_TCP_F_DATA_SUCCESS) {
 		struct request *rq = nvme_cid_to_rq(nvme_tcp_tagset(queue),
 					pdu->command_id);
+		struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
 
-		nvme_tcp_end_request(rq, NVME_SC_SUCCESS);
+		nvme_tcp_end_request(rq, le16_to_cpu(req->status));
 		queue->nr_cqe++;
 	}
 
@@ -2293,6 +2306,7 @@ static blk_status_t nvme_tcp_setup_cmd_pdu(struct nvme_ns *ns,
 		return ret;
 
 	req->state = NVME_TCP_SEND_CMD_PDU;
+	req->status = cpu_to_le16(NVME_SC_SUCCESS);
 	req->offset = 0;
 	req->data_sent = 0;
 	req->pdu_len = 0;

drivers/nvme/target/admin-cmd.c

@@ -1015,7 +1015,7 @@ u16 nvmet_parse_admin_cmd(struct nvmet_req *req)
 	if (unlikely(ret))
 		return ret;
 
-	if (nvmet_req_passthru_ctrl(req))
+	if (nvmet_is_passthru_req(req))
 		return nvmet_parse_passthru_admin_cmd(req);
 
 	switch (cmd->common.opcode) {

drivers/nvme/target/configfs.c

@@ -1028,7 +1028,7 @@ nvmet_subsys_attr_version_store_locked(struct nvmet_subsys *subsys,
 	}
 
 	/* passthru subsystems use the underlying controller's version */
-	if (nvmet_passthru_ctrl(subsys))
+	if (nvmet_is_passthru_subsys(subsys))
 		return -EINVAL;
 
 	ret = sscanf(page, "%d.%d.%d\n", &major, &minor, &tertiary);
@@ -1067,7 +1067,8 @@ static ssize_t nvmet_subsys_attr_serial_show(struct config_item *item,
 {
 	struct nvmet_subsys *subsys = to_subsys(item);
 
-	return snprintf(page, PAGE_SIZE, "%s\n", subsys->serial);
+	return snprintf(page, PAGE_SIZE, "%*s\n",
+			NVMET_SN_MAX_SIZE, subsys->serial);
 }
 
 static ssize_t

drivers/nvme/target/core.c

@@ -553,7 +553,7 @@ int nvmet_ns_enable(struct nvmet_ns *ns)
 	mutex_lock(&subsys->lock);
 	ret = 0;
 
-	if (nvmet_passthru_ctrl(subsys)) {
+	if (nvmet_is_passthru_subsys(subsys)) {
 		pr_info("cannot enable both passthru and regular namespaces for a single subsystem");
 		goto out_unlock;
 	}
@@ -869,7 +869,7 @@ static u16 nvmet_parse_io_cmd(struct nvmet_req *req)
 	if (unlikely(ret))
 		return ret;
 
-	if (nvmet_req_passthru_ctrl(req))
+	if (nvmet_is_passthru_req(req))
 		return nvmet_parse_passthru_io_cmd(req);
 
 	ret = nvmet_req_find_ns(req);
@@ -1206,6 +1206,9 @@ static void nvmet_init_cap(struct nvmet_ctrl *ctrl)
 	ctrl->cap |= (15ULL << 24);
 	/* maximum queue entries supported: */
 	ctrl->cap |= NVMET_QUEUE_SIZE - 1;
+
+	if (nvmet_is_passthru_subsys(ctrl->subsys))
+		nvmet_passthrough_override_cap(ctrl);
 }
 
 struct nvmet_ctrl *nvmet_ctrl_find_get(const char *subsysnqn,
@@ -1363,8 +1366,6 @@ u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
 		goto out_put_subsystem;
 	mutex_init(&ctrl->lock);
 
-	nvmet_init_cap(ctrl);
-
 	ctrl->port = req->port;
 
 	INIT_WORK(&ctrl->async_event_work, nvmet_async_event_work);
@@ -1378,6 +1379,7 @@ u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
 
 	kref_init(&ctrl->ref);
 	ctrl->subsys = subsys;
+	nvmet_init_cap(ctrl);
 	WRITE_ONCE(ctrl->aen_enabled, NVMET_AEN_CFG_OPTIONAL);
 
 	ctrl->changed_ns_list = kmalloc_array(NVME_MAX_CHANGED_NAMESPACES,

drivers/nvme/target/nvmet.h

@@ -582,7 +582,7 @@ int nvmet_passthru_ctrl_enable(struct nvmet_subsys *subsys);
 void nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys);
 u16 nvmet_parse_passthru_admin_cmd(struct nvmet_req *req);
 u16 nvmet_parse_passthru_io_cmd(struct nvmet_req *req);
-static inline struct nvme_ctrl *nvmet_passthru_ctrl(struct nvmet_subsys *subsys)
+static inline bool nvmet_is_passthru_subsys(struct nvmet_subsys *subsys)
 {
 	return subsys->passthru_ctrl;
 }
@@ -601,18 +601,19 @@ static inline u16 nvmet_parse_passthru_io_cmd(struct nvmet_req *req)
 {
 	return 0;
 }
-static inline struct nvme_ctrl *nvmet_passthru_ctrl(struct nvmet_subsys *subsys)
+static inline bool nvmet_is_passthru_subsys(struct nvmet_subsys *subsys)
 {
 	return NULL;
 }
 #endif /* CONFIG_NVME_TARGET_PASSTHRU */
 
-static inline struct nvme_ctrl *
-nvmet_req_passthru_ctrl(struct nvmet_req *req)
+static inline bool nvmet_is_passthru_req(struct nvmet_req *req)
 {
-	return nvmet_passthru_ctrl(nvmet_req_subsys(req));
+	return nvmet_is_passthru_subsys(nvmet_req_subsys(req));
 }
 
+void nvmet_passthrough_override_cap(struct nvmet_ctrl *ctrl);
+
 u16 errno_to_nvme_status(struct nvmet_req *req, int errno);
 u16 nvmet_report_invalid_opcode(struct nvmet_req *req);
 

drivers/nvme/target/passthru.c

@@ -20,6 +20,16 @@ MODULE_IMPORT_NS(NVME_TARGET_PASSTHRU);
  */
 static DEFINE_XARRAY(passthru_subsystems);
 
+void nvmet_passthrough_override_cap(struct nvmet_ctrl *ctrl)
+{
+	/*
+	 * Multiple command set support can only be declared if the underlying
+	 * controller actually supports it.
+	 */
+	if (!nvme_multi_css(ctrl->subsys->passthru_ctrl))
+		ctrl->cap &= ~(1ULL << 43);
+}
+
 static u16 nvmet_passthru_override_id_ctrl(struct nvmet_req *req)
 {
 	struct nvmet_ctrl *ctrl = req->sq->ctrl;
@@ -218,7 +228,7 @@ static int nvmet_passthru_map_sg(struct nvmet_req *req, struct request *rq)
 
 static void nvmet_passthru_execute_cmd(struct nvmet_req *req)
 {
-	struct nvme_ctrl *ctrl = nvmet_req_passthru_ctrl(req);
+	struct nvme_ctrl *ctrl = nvmet_req_subsys(req)->passthru_ctrl;
 	struct request_queue *q = ctrl->admin_q;
 	struct nvme_ns *ns = NULL;
 	struct request *rq = NULL;
@@ -299,7 +309,7 @@ static void nvmet_passthru_execute_cmd(struct nvmet_req *req)
  */
 static void nvmet_passthru_set_host_behaviour(struct nvmet_req *req)
 {
-	struct nvme_ctrl *ctrl = nvmet_req_passthru_ctrl(req);
+	struct nvme_ctrl *ctrl = nvmet_req_subsys(req)->passthru_ctrl;
 	struct nvme_feat_host_behavior *host;
 	u16 status = NVME_SC_INTERNAL;
 	int ret;

fs/Makefile

@@ -17,7 +17,7 @@ obj-y :=	open.o read_write.o file_table.o super.o \
 		kernel_read_file.o remap_range.o
 
 ifeq ($(CONFIG_BLOCK),y)
-obj-y +=	buffer.o block_dev.o direct-io.o mpage.o
+obj-y +=	buffer.o direct-io.o mpage.o
 else
 obj-y +=	no-block.o
 endif

fs/internal.h

@@ -18,7 +18,7 @@ struct user_namespace;
 struct pipe_inode_info;
 
 /*
- * block_dev.c
+ * block/bdev.c
  */
 #ifdef CONFIG_BLOCK
 extern void __init bdev_cache_init(void);