Documentation/bpf/fs_kfuncs.rst

+.. SPDX-License-Identifier: GPL-2.0
+
+.. _fs_kfuncs-header-label:
+
+=====================
+BPF filesystem kfuncs
+=====================
+
+BPF LSM programs need to access filesystem data from LSM hooks. The following
+BPF kfuncs can be used to get these data.
+
+ * ``bpf_get_file_xattr()``
+
+ * ``bpf_get_fsverity_digest()``
+
+To avoid recursions, these kfuncs follow the following rules:
+
+1. These kfuncs are only permitted from BPF LSM function.
+2. These kfuncs should not call into other LSM hooks, i.e. security_*(). For
+   example, ``bpf_get_file_xattr()`` does not use ``vfs_getxattr()``, because
+   the latter calls LSM hook ``security_inode_getxattr``.

Documentation/bpf/index.rst

@@ -21,6 +21,7 @@ that goes into great technical depth about the BPF Architecture.
    helpers
    kfuncs
    cpumasks
+   fs_kfuncs
    programs
    maps
    bpf_prog_run

Documentation/networking/can.rst

@@ -168,7 +168,7 @@ reflect the correct [#f1]_ traffic on the node the loopback of the sent
 data has to be performed right after a successful transmission. If
 the CAN network interface is not capable of performing the loopback for
 some reason the SocketCAN core can do this task as a fallback solution.
-See :ref:`socketcan-local-loopback1` for details (recommended).
+See :ref:`socketcan-local-loopback2` for details (recommended).
 
 The loopback functionality is enabled by default to reflect standard
 networking behaviour for CAN applications. Due to some requests from
@@ -444,6 +444,24 @@ definitions are specified for CAN specific MTUs in include/linux/can.h:
   #define CANFD_MTU (sizeof(struct canfd_frame)) == 72  => CAN FD frame
 
 
+Returned Message Flags
+----------------------
+
+When using the system call recvmsg(2) on a RAW or a BCM socket, the
+msg->msg_flags field may contain the following flags:
+
+MSG_DONTROUTE:
+	set when the received frame was created on the local host.
+
+MSG_CONFIRM:
+	set when the frame was sent via the socket it is received on.
+	This flag can be interpreted as a 'transmission confirmation' when the
+	CAN driver supports the echo of frames on driver level, see
+	:ref:`socketcan-local-loopback1` and :ref:`socketcan-local-loopback2`.
+	(Note: In order to receive such messages on a RAW socket,
+	CAN_RAW_RECV_OWN_MSGS must be set.)
+
+
 .. _socketcan-raw-sockets:
 
 RAW Protocol Sockets with can_filters (SOCK_RAW)
@@ -693,22 +711,6 @@ where the CAN_INV_FILTER flag is set in order to notch single CAN IDs or
 CAN ID ranges from the incoming traffic.
 
 
-RAW Socket Returned Message Flags
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-When using recvmsg() call, the msg->msg_flags may contain following flags:
-
-MSG_DONTROUTE:
-	set when the received frame was created on the local host.
-
-MSG_CONFIRM:
-	set when the frame was sent via the socket it is received on.
-	This flag can be interpreted as a 'transmission confirmation' when the
-	CAN driver supports the echo of frames on driver level, see
-	:ref:`socketcan-local-loopback1` and :ref:`socketcan-local-loopback2`.
-	In order to receive such messages, CAN_RAW_RECV_OWN_MSGS must be set.
-
-
 Broadcast Manager Protocol Sockets (SOCK_DGRAM)
 -----------------------------------------------
 
@@ -1148,6 +1150,39 @@ tuning on deep embedded systems'. The author is running a MPC603e
 load without any problems ...
 
 
+Switchable Termination Resistors
+--------------------------------
+
+CAN bus requires a specific impedance across the differential pair,
+typically provided by two 120Ohm resistors on the farthest nodes of
+the bus. Some CAN controllers support activating / deactivating a
+termination resistor(s) to provide the correct impedance.
+
+Query the available resistances::
+
+    $ ip -details link show can0
+    ...
+    termination 120 [ 0, 120 ]
+
+Activate the terminating resistor::
+
+    $ ip link set dev can0 type can termination 120
+
+Deactivate the terminating resistor::
+
+    $ ip link set dev can0 type can termination 0
+
+To enable termination resistor support to a can-controller, either
+implement in the controller's struct can-priv::
+
+    termination_const
+    termination_const_cnt
+    do_set_termination
+
+or add gpio control with the device tree entries from
+Documentation/devicetree/bindings/net/can/can-controller.yaml
+
+
 The Virtual CAN Driver (vcan)
 -----------------------------
 

Makefile.rhelver

@@ -12,7 +12,7 @@ RHEL_MINOR = 7
 #
 # Use this spot to avoid future merge conflicts.
 # Do not trim this comment.
-RHEL_RELEASE = 575
+RHEL_RELEASE = 576
 
 #
 # ZSTREAM

arch/x86/kernel/setup.c

@@ -680,7 +680,7 @@ static void rh_check_supported(void)
 
 	/* RHEL supports single cpu on guests only */
 	if (((topology_num_threads_per_package() * __max_threads_per_core) == 1) &&
-	    !guest && is_kdump_kernel()) {
+	    !guest && !is_kdump_kernel()) {
 		pr_crit("Detected single cpu native boot.\n");
 		pr_crit("Important:  In this kernel, single threaded, single CPU 64-bit physical systems are unsupported.");
 	}

arch/x86/kvm/vmx/main.c

@@ -126,7 +126,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 
 	.sched_in = vmx_sched_in,
 
-	.cpu_dirty_log_size = PML_ENTITY_NUM,
+	.cpu_dirty_log_size = PML_LOG_NR_ENTRIES,
 	.update_cpu_dirty_logging = vmx_update_cpu_dirty_logging,
 
 	.nested_ops = &vmx_nested_ops,

arch/x86/kvm/vmx/nested.c

@@ -3380,7 +3380,7 @@ static int nested_vmx_write_pml_buffer(struct kvm_vcpu *vcpu, gpa_t gpa)
 	if (!nested_cpu_has_pml(vmcs12))
 		return 0;
 
-	if (vmcs12->guest_pml_index >= PML_ENTITY_NUM) {
+	if (vmcs12->guest_pml_index >= PML_LOG_NR_ENTRIES) {
 		vmx->nested.pml_full = true;
 		return 1;
 	}

arch/x86/kvm/vmx/vmx.c

@@ -4790,7 +4790,7 @@ static void init_vmcs(struct vcpu_vmx *vmx)
 
 	if (enable_pml) {
 		vmcs_write64(PML_ADDRESS, page_to_phys(vmx->pml_pg));
-		vmcs_write16(GUEST_PML_INDEX, PML_ENTITY_NUM - 1);
+		vmcs_write16(GUEST_PML_INDEX, PML_HEAD_INDEX);
 	}
 
 	vmx_write_encls_bitmap(&vmx->vcpu, NULL);
@@ -6202,32 +6202,40 @@ static void vmx_destroy_pml_buffer(struct vcpu_vmx *vmx)
 static void vmx_flush_pml_buffer(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
+	u16 pml_idx, pml_tail_index;
 	u64 *pml_buf;
-	u16 pml_idx;
+	int i;
 
 	pml_idx = vmcs_read16(GUEST_PML_INDEX);
 
 	/* Do nothing if PML buffer is empty */
-	if (pml_idx == (PML_ENTITY_NUM - 1))
+	if (pml_idx == PML_HEAD_INDEX)
 		return;
+	/*
+	 * PML index always points to the next available PML buffer entity
+	 * unless PML log has just overflowed.
+	 */
+	pml_tail_index = (pml_idx >= PML_LOG_NR_ENTRIES) ? 0 : pml_idx + 1;
 
-	/* PML index always points to next available PML buffer entity */
-	if (pml_idx >= PML_ENTITY_NUM)
-		pml_idx = 0;
-	else
-		pml_idx++;
-
+	/*
+	 * PML log is written backwards: the CPU first writes the entry 511
+	 * then the entry 510, and so on.
+	 *
+	 * Read the entries in the same order they were written, to ensure that
+	 * the dirty ring is filled in the same order the CPU wrote them.
+	 */
 	pml_buf = page_address(vmx->pml_pg);
-	for (; pml_idx < PML_ENTITY_NUM; pml_idx++) {
+
+	for (i = PML_HEAD_INDEX; i >= pml_tail_index; i--) {
 		u64 gpa;
 
-		gpa = pml_buf[pml_idx];
+		gpa = pml_buf[i];
 		WARN_ON(gpa & (PAGE_SIZE - 1));
 		kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT);
 	}
 
 	/* reset PML index */
-	vmcs_write16(GUEST_PML_INDEX, PML_ENTITY_NUM - 1);
+	vmcs_write16(GUEST_PML_INDEX, PML_HEAD_INDEX);
 }
 
 static void vmx_dump_sel(char *name, uint32_t sel)

arch/x86/kvm/vmx/vmx.h

@@ -336,7 +336,10 @@ struct vcpu_vmx {
 	bool ple_window_dirty;
 
 	/* Support for PML */
-#define PML_ENTITY_NUM		512
+#define PML_LOG_NR_ENTRIES	512
+	/* PML is written backwards: this is the first entry written by the CPU */
+#define PML_HEAD_INDEX		(PML_LOG_NR_ENTRIES-1)
+
 	struct page *pml_pg;
 
 	/* apic deadline value in host tsc */

crypto/async_tx/async_xor.c

@@ -389,32 +389,6 @@ async_xor_val_offs(struct page *dest, unsigned int offset,
 }
 EXPORT_SYMBOL_GPL(async_xor_val_offs);
 
-/**
- * async_xor_val - attempt a xor parity check with a dma engine.
- * @dest: destination page used if the xor is performed synchronously
- * @src_list: array of source pages
- * @offset: offset in pages to start transaction
- * @src_cnt: number of source pages
- * @len: length in bytes
- * @result: 0 if sum == 0 else non-zero
- * @submit: submission / completion modifiers
- *
- * honored flags: ASYNC_TX_ACK
- *
- * src_list note: if the dest is also a source it must be at index zero.
- * The contents of this array will be overwritten if a scribble region
- * is not specified.
- */
-struct dma_async_tx_descriptor *
-async_xor_val(struct page *dest, struct page **src_list, unsigned int offset,
-	      int src_cnt, size_t len, enum sum_check_flags *result,
-	      struct async_submit_ctl *submit)
-{
-	return async_xor_val_offs(dest, offset, src_list, NULL, src_cnt,
-			len, result, submit);
-}
-EXPORT_SYMBOL_GPL(async_xor_val);
-
 MODULE_AUTHOR("Intel Corporation");
 MODULE_DESCRIPTION("asynchronous xor/xor-zero-sum api");
 MODULE_LICENSE("GPL");

drivers/bluetooth/btusb.c

@@ -371,6 +371,8 @@ static const struct usb_device_id quirks_table[] = {
 						     BTUSB_WIDEBAND_SPEECH },
 	{ USB_DEVICE(0x0489, 0xe0fc), .driver_info = BTUSB_QCA_WCN6855 |
 						     BTUSB_WIDEBAND_SPEECH },
+	{ USB_DEVICE(0x0489, 0xe0f3), .driver_info = BTUSB_QCA_WCN6855 |
+						     BTUSB_WIDEBAND_SPEECH },
 
 	/* Broadcom BCM2035 */
 	{ USB_DEVICE(0x0a5c, 0x2009), .driver_info = BTUSB_BCM92035 },

drivers/md/Kconfig

@@ -58,7 +58,7 @@ config MD_BITMAP_FILE
 	  actually sitting on the MD device.
 
 config MD_LINEAR
-	tristate "Linear (append) mode (deprecated)"
+	tristate "Linear (append) mode"
 	depends on BLK_DEV_MD
 	help
 	  If you say Y here, then your multiple devices driver will be able to

drivers/md/Makefile

@@ -29,13 +29,13 @@ dm-zoned-y	+= dm-zoned-target.o dm-zoned-metadata.o dm-zoned-reclaim.o
 
 md-mod-y	+= md.o md-bitmap.o
 raid456-y	+= raid5.o raid5-cache.o raid5-ppl.o
-linear-y	+= md-linear.o
 multipath-y	+= md-multipath.o
 faulty-y	+= md-faulty.o
+linear-y       += md-linear.o
 
 # Note: link order is important.  All raid personalities
-# and must come before md.o, as they each initialise 
-# themselves, and md.o may use the personalities when it 
+# and must come before md.o, as they each initialise
+# themselves, and md.o may use the personalities when it
 # auto-initialised.
 
 obj-$(CONFIG_MD_LINEAR)		+= linear.o

drivers/md/md-bitmap.c

@@ -29,8 +29,10 @@
 #include <linux/buffer_head.h>
 #include <linux/seq_file.h>
 #include <trace/events/block.h>
+
 #include "md.h"
 #include "md-bitmap.h"
+#include "md-cluster.h"
 
 #define BITMAP_MAJOR_LO 3
 /* version 4 insists the bitmap is in little-endian order
@@ -426,8 +428,8 @@ static int __write_sb_page(struct md_rdev *rdev, struct bitmap *bitmap,
 	struct block_device *bdev;
 	struct mddev *mddev = bitmap->mddev;
 	struct bitmap_storage *store = &bitmap->storage;
-	unsigned int bitmap_limit = (bitmap->storage.file_pages - pg_index) <<
-		PAGE_SHIFT;
+	unsigned long num_pages = bitmap->storage.file_pages;
+	unsigned int bitmap_limit = (num_pages - pg_index % num_pages) << PAGE_SHIFT;
 	loff_t sboff, offset = mddev->bitmap_info.offset;
 	sector_t ps = pg_index * PAGE_SIZE / SECTOR_SIZE;
 	unsigned int size = PAGE_SIZE;
@@ -436,7 +438,7 @@ static int __write_sb_page(struct md_rdev *rdev, struct bitmap *bitmap,
 
 	bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
 	/* we compare length (page numbers), not page offset. */
-	if ((pg_index - store->sb_index) == store->file_pages - 1) {
+	if ((pg_index - store->sb_index) == num_pages - 1) {
 		unsigned int last_page_size = store->bytes & (PAGE_SIZE - 1);
 
 		if (last_page_size == 0)
@@ -942,7 +944,7 @@ static int md_bitmap_read_sb(struct bitmap *bitmap)
 				bmname(bitmap), err);
 			goto out_no_sb;
 		}
-		bitmap->cluster_slot = md_cluster_ops->slot_number(bitmap->mddev);
+		bitmap->cluster_slot = bitmap->mddev->cluster_ops->slot_number(bitmap->mddev);
 		goto re_read;
 	}
 
@@ -2021,7 +2023,7 @@ static void md_bitmap_free(void *data)
 		sysfs_put(bitmap->sysfs_can_clear);
 
 	if (mddev_is_clustered(bitmap->mddev) && bitmap->mddev->cluster_info &&
-		bitmap->cluster_slot == md_cluster_ops->slot_number(bitmap->mddev))
+		bitmap->cluster_slot == bitmap->mddev->cluster_ops->slot_number(bitmap->mddev))
 		md_cluster_stop(bitmap->mddev);
 
 	/* Shouldn't be needed - but just in case.... */
@@ -2229,7 +2231,7 @@ static int bitmap_load(struct mddev *mddev)
 		mddev_create_serial_pool(mddev, rdev);
 
 	if (mddev_is_clustered(mddev))
-		md_cluster_ops->load_bitmaps(mddev, mddev->bitmap_info.nodes);
+		mddev->cluster_ops->load_bitmaps(mddev, mddev->bitmap_info.nodes);
 
 	/* Clear out old bitmap info first:  Either there is none, or we
 	 * are resuming after someone else has possibly changed things,

drivers/md/md-cluster.c

@@ -1166,7 +1166,7 @@ static int resize_bitmaps(struct mddev *mddev, sector_t newsize, sector_t oldsiz
 		struct dlm_lock_resource *bm_lockres;
 		char str[64];
 
-		if (i == md_cluster_ops->slot_number(mddev))
+		if (i == slot_number(mddev))
 			continue;
 
 		bitmap = mddev->bitmap_ops->get_from_slot(mddev, i);
@@ -1216,7 +1216,7 @@ static int resize_bitmaps(struct mddev *mddev, sector_t newsize, sector_t oldsiz
  */
 static int cluster_check_sync_size(struct mddev *mddev)
 {
-	int current_slot = md_cluster_ops->slot_number(mddev);
+	int current_slot = slot_number(mddev);
 	int node_num = mddev->bitmap_info.nodes;
 	struct dlm_lock_resource *bm_lockres;
 	struct md_bitmap_stats stats;
@@ -1612,7 +1612,14 @@ static int gather_bitmaps(struct md_rdev *rdev)
 	return err;
 }
 
-static const struct md_cluster_operations cluster_ops = {
+static struct md_cluster_operations cluster_ops = {
+	.head = {
+		.type	= MD_CLUSTER,
+		.id	= ID_CLUSTER,
+		.name	= "cluster",
+		.owner	= THIS_MODULE,
+	},
+
 	.join   = join,
 	.leave  = leave,
 	.slot_number = slot_number,
@@ -1642,13 +1649,12 @@ static int __init cluster_init(void)
 {
 	pr_warn("md-cluster: support raid1 and raid10 (limited support)\n");
 	pr_info("Registering Cluster MD functions\n");
-	register_md_cluster_operations(&cluster_ops, THIS_MODULE);
-	return 0;
+	return register_md_submodule(&cluster_ops.head);
 }
 
 static void cluster_exit(void)
 {
-	unregister_md_cluster_operations();
+	unregister_md_submodule(&cluster_ops.head);
 }
 
 module_init(cluster_init);

drivers/md/md-cluster.h

@@ -10,6 +10,8 @@ struct mddev;
 struct md_rdev;
 
 struct md_cluster_operations {
+	struct md_submodule_head head;
+
 	int (*join)(struct mddev *mddev, int nodes);
 	int (*leave)(struct mddev *mddev);
 	int (*slot_number)(struct mddev *mddev);
@@ -35,4 +37,8 @@ struct md_cluster_operations {
 	void (*update_size)(struct mddev *mddev, sector_t old_dev_sectors);
 };
 
+extern int md_setup_cluster(struct mddev *mddev, int nodes);
+extern void md_cluster_stop(struct mddev *mddev);
+extern void md_reload_sb(struct mddev *mddev, int raid_disk);
+
 #endif /* _MD_CLUSTER_H */

drivers/md/md-faulty.c

@@ -55,7 +55,6 @@
 #define MaxFault	50
 #include <linux/blkdev.h>
 #include <linux/module.h>
-#include <linux/raid/md_u.h>
 #include <linux/slab.h>
 #include "md.h"
 #include <linux/seq_file.h>
@@ -350,9 +349,13 @@ static void faulty_free(struct mddev *mddev, void *priv)
 
 static struct md_personality faulty_personality =
 {
-	.name		= "faulty",
-	.level		= LEVEL_FAULTY,
-	.owner		= THIS_MODULE,
+	.head = {
+		.type   = MD_PERSONALITY,
+		.id     = ID_FAULTY,
+		.name   = "faulty",
+		.owner  = THIS_MODULE,
+	},
+
 	.make_request	= faulty_make_request,
 	.run		= faulty_run,
 	.free		= faulty_free,
@@ -363,12 +366,12 @@ static struct md_personality faulty_personality =
 
 static int __init raid_init(void)
 {
-	return register_md_personality(&faulty_personality);
+	return register_md_submodule(&faulty_personality.head);
 }
 
 static void raid_exit(void)
 {
-	unregister_md_personality(&faulty_personality);
+	unregister_md_submodule(&faulty_personality.head);
 }
 
 module_init(raid_init);

drivers/md/md-linear.c

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
-   linear.c : Multiple Devices driver for Linux
-	      Copyright (C) 1994-96 Marc ZYNGIER
-	      <zyngier@ufr-info-p7.ibp.fr> or
-	      <maz@gloups.fdn.fr>
-
-   Linear mode management functions.
-
-*/
+ * linear.c : Multiple Devices driver for Linux Copyright (C) 1994-96 Marc
+ * ZYNGIER <zyngier@ufr-info-p7.ibp.fr> or <maz@gloups.fdn.fr>
+ */
 
 #include <linux/blkdev.h>
-#include <linux/raid/md_u.h>
 #include <linux/seq_file.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <trace/events/block.h>
 #include "md.h"
-#include "md-linear.h"
+
+struct dev_info {
+	struct md_rdev	*rdev;
+	sector_t	end_sector;
+};
+
+struct linear_conf {
+	struct rcu_head         rcu;
+	sector_t                array_sectors;
+	/* a copy of mddev->raid_disks */
+	int                     raid_disks;
+	struct dev_info         disks[] __counted_by(raid_disks);
+};
 
 /*
  * find which device holds a particular offset
@@ -65,6 +71,9 @@ static int linear_set_limits(struct mddev *mddev)
 	int err;
 
 	md_init_stacking_limits(&lim);
+	lim.max_hw_sectors = mddev->chunk_sectors;
+	lim.max_write_zeroes_sectors = mddev->chunk_sectors;
+	lim.io_min = mddev->chunk_sectors << 9;
 	err = mddev_stack_rdev_limits(mddev, &lim, MDDEV_STACK_INTEGRITY);
 	if (err)
 		return err;
@@ -76,11 +85,26 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
 {
 	struct linear_conf *conf;
 	struct md_rdev *rdev;
-	int i, cnt;
+	int ret = -EINVAL;
+	int cnt;
+	int i;
 
 	conf = kzalloc(struct_size(conf, disks, raid_disks), GFP_KERNEL);
 	if (!conf)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
+
+	/*
+	 * conf->raid_disks is copy of mddev->raid_disks. The reason to
+	 * keep a copy of mddev->raid_disks in struct linear_conf is,
+	 * mddev->raid_disks may not be consistent with pointers number of
+	 * conf->disks[] when it is updated in linear_add() and used to
+	 * iterate old conf->disks[] earray in linear_congested().
+	 * Here conf->raid_disks is always consitent with number of
+	 * pointers in conf->disks[] array, and mddev->private is updated
+	 * with rcu_assign_pointer() in linear_addr(), such race can be
+	 * avoided.
+	 */
+	conf->raid_disks = raid_disks;
 
 	cnt = 0;
 	conf->array_sectors = 0;
@@ -112,12 +136,6 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
 		goto out;
 	}
 
-	if (linear_set_limits(mddev)) {
-		pr_warn("md/linear:%s: set limits failed. Aborting!\n",
-			mdname(mddev));
-		goto out;
-	}
-
 	/*
 	 * Here we calculate the device offsets.
 	 */
@@ -128,37 +146,31 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
 			conf->disks[i-1].end_sector +
 			conf->disks[i].rdev->sectors;
 
-	/*
-	 * conf->raid_disks is copy of mddev->raid_disks. The reason to
-	 * keep a copy of mddev->raid_disks in struct linear_conf is,
-	 * mddev->raid_disks may not be consistent with pointers number of
-	 * conf->disks[] when it is updated in linear_add() and used to
-	 * iterate old conf->disks[] earray in linear_congested().
-	 * Here conf->raid_disks is always consitent with number of
-	 * pointers in conf->disks[] array, and mddev->private is updated
-	 * with rcu_assign_pointer() in linear_addr(), such race can be
-	 * avoided.
-	 */
-	conf->raid_disks = raid_disks;
+	if (!mddev_is_dm(mddev)) {
+		ret = linear_set_limits(mddev);
+		if (ret)
+			goto out;
+	}
 
 	return conf;
 
 out:
 	kfree(conf);
-	return NULL;
+	return ERR_PTR(ret);
 }
 
-static int linear_run (struct mddev *mddev)
+static int linear_run(struct mddev *mddev)
 {
 	struct linear_conf *conf;
 	int ret;
 
 	if (md_check_no_bitmap(mddev))
 		return -EINVAL;
+
 	conf = linear_conf(mddev, mddev->raid_disks);
+	if (IS_ERR(conf))
+		return PTR_ERR(conf);
 
-	if (!conf)
-		return 1;
 	mddev->private = conf;
 	md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
 
@@ -198,7 +210,6 @@ static int linear_add(struct mddev *mddev, struct md_rdev *rdev)
 	 * in linear_congested(), therefore kfree_rcu() is used to free
 	 * oldconf until no one uses it anymore.
 	 */
-	mddev_suspend(mddev, true);
 	oldconf = rcu_dereference_protected(mddev->private,
 			lockdep_is_held(&mddev->reconfig_mutex));
 	mddev->raid_disks++;
@@ -207,7 +218,6 @@ static int linear_add(struct mddev *mddev, struct md_rdev *rdev)
 	rcu_assign_pointer(mddev->private, newconf);
 	md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
 	set_capacity_and_notify(mddev->gendisk, mddev->array_sectors);
-	mddev_resume(mddev);
 	kfree_rcu(oldconf, rcu);
 	return 0;
 }
@@ -248,6 +258,13 @@ static bool linear_make_request(struct mddev *mddev, struct bio *bio)
 		/* This bio crosses a device boundary, so we have to split it */
 		struct bio *split = bio_split(bio, end_sector - bio_sector,
 					      GFP_NOIO, &mddev->bio_set);
+
+		if (IS_ERR(split)) {
+			bio->bi_status = errno_to_blk_status(PTR_ERR(split));
+			bio_endio(bio);
+			return true;
+		}
+
 		bio_chain(split, bio);
 		submit_bio_noacct(bio);
 		bio = split;
@@ -282,7 +299,7 @@ static bool linear_make_request(struct mddev *mddev, struct bio *bio)
 	return true;
 }
 
-static void linear_status (struct seq_file *seq, struct mddev *mddev)
+static void linear_status(struct seq_file *seq, struct mddev *mddev)
 {
 	seq_printf(seq, " %dk rounding", mddev->chunk_sectors / 2);
 }
@@ -301,11 +318,14 @@ static void linear_quiesce(struct mddev *mddev, int state)
 {
 }
 
-static struct md_personality linear_personality =
-{
-	.name		= "linear",
-	.level		= LEVEL_LINEAR,
-	.owner		= THIS_MODULE,
+static struct md_personality linear_personality = {
+	.head = {
+		.type	= MD_PERSONALITY,
+		.id	= ID_LINEAR,
+		.name	= "linear",
+		.owner	= THIS_MODULE,
+	},
+
 	.make_request	= linear_make_request,
 	.run		= linear_run,
 	.free		= linear_free,
@@ -316,14 +336,14 @@ static struct md_personality linear_personality =
 	.error_handler	= linear_error,
 };
 
-static int __init linear_init (void)
+static int __init linear_init(void)
 {
-	return register_md_personality (&linear_personality);
+	return register_md_submodule(&linear_personality.head);
 }
 
-static void linear_exit (void)
+static void linear_exit(void)
 {
-	unregister_md_personality (&linear_personality);
+	unregister_md_submodule(&linear_personality.head);
 }
 
 module_init(linear_init);

drivers/md/md-linear.h

-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _LINEAR_H
-#define _LINEAR_H
-
-struct dev_info {
-	struct md_rdev	*rdev;
-	sector_t	end_sector;
-};
-
-struct linear_conf
-{
-	struct rcu_head		rcu;
-	sector_t		array_sectors;
-	int			raid_disks; /* a copy of mddev->raid_disks */
-	struct dev_info		disks[];
-};
-#endif

drivers/md/md-multipath.c

@@ -13,7 +13,6 @@
 
 #include <linux/blkdev.h>
 #include <linux/module.h>
-#include <linux/raid/md_u.h>
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include "md.h"
@@ -430,9 +429,12 @@ static void multipath_free(struct mddev *mddev, void *priv)
 
 static struct md_personality multipath_personality =
 {
-	.name		= "multipath",
-	.level		= LEVEL_MULTIPATH,
-	.owner		= THIS_MODULE,
+	.head = {
+		.type   = MD_PERSONALITY,
+		.id     = ID_MULTIPATH,
+		.name   = "multipath",
+		.owner  = THIS_MODULE,
+	},
 	.make_request	= multipath_make_request,
 	.run		= multipath_run,
 	.free		= multipath_free,
@@ -445,12 +447,12 @@ static struct md_personality multipath_personality =
 
 static int __init multipath_init (void)
 {
-	return register_md_personality (&multipath_personality);
+	return register_md_submodule(&multipath_personality.head);
 }
 
 static void __exit multipath_exit (void)
 {
-	unregister_md_personality (&multipath_personality);
+	unregister_md_submodule(&multipath_personality.head);
 }
 
 module_init(multipath_init);