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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (C) 2015, SUSE
   4 */
   5
   6
   7#include <linux/module.h>
   8#include <linux/kthread.h>
   9#include <linux/dlm.h>
  10#include <linux/sched.h>
  11#include <linux/raid/md_p.h>
  12#include "md.h"
  13#include "md-bitmap.h"
  14#include "md-cluster.h"
  15
  16#define LVB_SIZE	64
  17#define NEW_DEV_TIMEOUT 5000
  18#define WAIT_DLM_LOCK_TIMEOUT (30 * HZ)
  19
  20struct dlm_lock_resource {
  21	dlm_lockspace_t *ls;
  22	struct dlm_lksb lksb;
  23	char *name; /* lock name. */
  24	uint32_t flags; /* flags to pass to dlm_lock() */
  25	wait_queue_head_t sync_locking; /* wait queue for synchronized locking */
  26	bool sync_locking_done;
  27	void (*bast)(void *arg, int mode); /* blocking AST function pointer*/
  28	struct mddev *mddev; /* pointing back to mddev. */
  29	int mode;
  30};
  31
  32struct resync_info {
  33	__le64 lo;
  34	__le64 hi;
  35};
  36
  37/* md_cluster_info flags */
  38#define		MD_CLUSTER_WAITING_FOR_NEWDISK		1
  39#define		MD_CLUSTER_SUSPEND_READ_BALANCING	2
  40#define		MD_CLUSTER_BEGIN_JOIN_CLUSTER		3
  41
  42/* Lock the send communication. This is done through
  43 * bit manipulation as opposed to a mutex in order to
  44 * accommodate lock and hold. See next comment.
  45 */
  46#define		MD_CLUSTER_SEND_LOCK			4
  47/* If cluster operations (such as adding a disk) must lock the
  48 * communication channel, so as to perform extra operations
  49 * (update metadata) and no other operation is allowed on the
  50 * MD. Token needs to be locked and held until the operation
  51 * completes witha md_update_sb(), which would eventually release
  52 * the lock.
  53 */
  54#define		MD_CLUSTER_SEND_LOCKED_ALREADY		5
  55/* We should receive message after node joined cluster and
  56 * set up all the related infos such as bitmap and personality */
  57#define		MD_CLUSTER_ALREADY_IN_CLUSTER		6
  58#define		MD_CLUSTER_PENDING_RECV_EVENT		7
  59#define 	MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD		8
  60#define		MD_CLUSTER_WAITING_FOR_SYNC		9
  61
  62struct md_cluster_info {
  63	struct mddev *mddev; /* the md device which md_cluster_info belongs to */
  64	/* dlm lock space and resources for clustered raid. */
  65	dlm_lockspace_t *lockspace;
  66	int slot_number;
  67	struct completion completion;
  68	struct mutex recv_mutex;
  69	struct dlm_lock_resource *bitmap_lockres;
  70	struct dlm_lock_resource **other_bitmap_lockres;
  71	struct dlm_lock_resource *resync_lockres;
  72	struct list_head suspend_list;
  73
  74	spinlock_t suspend_lock;
  75	/* record the region which write should be suspended */
  76	sector_t suspend_lo;
  77	sector_t suspend_hi;
  78	int suspend_from; /* the slot which broadcast suspend_lo/hi */
  79
  80	struct md_thread __rcu *recovery_thread;
  81	unsigned long recovery_map;
  82	/* communication loc resources */
  83	struct dlm_lock_resource *ack_lockres;
  84	struct dlm_lock_resource *message_lockres;
  85	struct dlm_lock_resource *token_lockres;
  86	struct dlm_lock_resource *no_new_dev_lockres;
  87	struct md_thread __rcu *recv_thread;
  88	struct completion newdisk_completion;
  89	wait_queue_head_t wait;
  90	unsigned long state;
  91	/* record the region in RESYNCING message */
  92	sector_t sync_low;
  93	sector_t sync_hi;
  94};
  95
  96/* For compatibility, add the new msg_type at the end. */
  97enum msg_type {
  98	METADATA_UPDATED = 0,
  99	RESYNCING,
 100	NEWDISK,
 101	REMOVE,
 102	RE_ADD,
 103	BITMAP_NEEDS_SYNC,
 104	CHANGE_CAPACITY,
 105	BITMAP_RESIZE,
 106	RESYNCING_START,
 107};
 108
 109struct cluster_msg {
 110	__le32 type;
 111	__le32 slot;
 112	/* TODO: Unionize this for smaller footprint */
 113	__le64 low;
 114	__le64 high;
 115	char uuid[16];
 116	__le32 raid_slot;
 117};
 118
 119static void sync_ast(void *arg)
 120{
 121	struct dlm_lock_resource *res;
 122
 123	res = arg;
 124	res->sync_locking_done = true;
 125	wake_up(&res->sync_locking);
 126}
 127
 128static int dlm_lock_sync(struct dlm_lock_resource *res, int mode)
 129{
 130	int ret = 0;
 131
 132	ret = dlm_lock(res->ls, mode, &res->lksb,
 133			res->flags, res->name, strlen(res->name),
 134			0, sync_ast, res, res->bast);
 135	if (ret)
 136		return ret;
 137	ret = wait_event_timeout(res->sync_locking, res->sync_locking_done,
 138				WAIT_DLM_LOCK_TIMEOUT);
 139	res->sync_locking_done = false;
 140	if (!ret) {
 141		pr_err("locking DLM '%s' timeout!\n", res->name);
 142		return -EBUSY;
 143	}
 144	if (res->lksb.sb_status == 0)
 145		res->mode = mode;
 146	return res->lksb.sb_status;
 147}
 148
 149static int dlm_unlock_sync(struct dlm_lock_resource *res)
 150{
 151	return dlm_lock_sync(res, DLM_LOCK_NL);
 152}
 153
 154/*
 155 * An variation of dlm_lock_sync, which make lock request could
 156 * be interrupted
 157 */
 158static int dlm_lock_sync_interruptible(struct dlm_lock_resource *res, int mode,
 159				       struct mddev *mddev)
 160{
 161	int ret = 0;
 162
 163	ret = dlm_lock(res->ls, mode, &res->lksb,
 164			res->flags, res->name, strlen(res->name),
 165			0, sync_ast, res, res->bast);
 166	if (ret)
 167		return ret;
 168
 169	wait_event(res->sync_locking, res->sync_locking_done
 170				      || kthread_should_stop()
 171				      || test_bit(MD_CLOSING, &mddev->flags));
 172	if (!res->sync_locking_done) {
 173		/*
 174		 * the convert queue contains the lock request when request is
 175		 * interrupted, and sync_ast could still be run, so need to
 176		 * cancel the request and reset completion
 177		 */
 178		ret = dlm_unlock(res->ls, res->lksb.sb_lkid, DLM_LKF_CANCEL,
 179			&res->lksb, res);
 180		res->sync_locking_done = false;
 181		if (unlikely(ret != 0))
 182			pr_info("failed to cancel previous lock request "
 183				 "%s return %d\n", res->name, ret);
 184		return -EPERM;
 185	} else
 186		res->sync_locking_done = false;
 187	if (res->lksb.sb_status == 0)
 188		res->mode = mode;
 189	return res->lksb.sb_status;
 190}
 191
 192static struct dlm_lock_resource *lockres_init(struct mddev *mddev,
 193		char *name, void (*bastfn)(void *arg, int mode), int with_lvb)
 194{
 195	struct dlm_lock_resource *res = NULL;
 196	int ret, namelen;
 197	struct md_cluster_info *cinfo = mddev->cluster_info;
 198
 199	res = kzalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL);
 200	if (!res)
 201		return NULL;
 202	init_waitqueue_head(&res->sync_locking);
 203	res->sync_locking_done = false;
 204	res->ls = cinfo->lockspace;
 205	res->mddev = mddev;
 206	res->mode = DLM_LOCK_IV;
 207	namelen = strlen(name);
 208	res->name = kzalloc(namelen + 1, GFP_KERNEL);
 209	if (!res->name) {
 210		pr_err("md-cluster: Unable to allocate resource name for resource %s\n", name);
 211		goto out_err;
 212	}
 213	strscpy(res->name, name, namelen + 1);
 214	if (with_lvb) {
 215		res->lksb.sb_lvbptr = kzalloc(LVB_SIZE, GFP_KERNEL);
 216		if (!res->lksb.sb_lvbptr) {
 217			pr_err("md-cluster: Unable to allocate LVB for resource %s\n", name);
 218			goto out_err;
 219		}
 220		res->flags = DLM_LKF_VALBLK;
 221	}
 222
 223	if (bastfn)
 224		res->bast = bastfn;
 225
 226	res->flags |= DLM_LKF_EXPEDITE;
 227
 228	ret = dlm_lock_sync(res, DLM_LOCK_NL);
 229	if (ret) {
 230		pr_err("md-cluster: Unable to lock NL on new lock resource %s\n", name);
 231		goto out_err;
 232	}
 233	res->flags &= ~DLM_LKF_EXPEDITE;
 234	res->flags |= DLM_LKF_CONVERT;
 235
 236	return res;
 237out_err:
 238	kfree(res->lksb.sb_lvbptr);
 239	kfree(res->name);
 240	kfree(res);
 241	return NULL;
 242}
 243
 244static void lockres_free(struct dlm_lock_resource *res)
 245{
 246	int ret = 0;
 247
 248	if (!res)
 249		return;
 250
 251	/*
 252	 * use FORCEUNLOCK flag, so we can unlock even the lock is on the
 253	 * waiting or convert queue
 254	 */
 255	ret = dlm_unlock(res->ls, res->lksb.sb_lkid, DLM_LKF_FORCEUNLOCK,
 256		&res->lksb, res);
 257	if (unlikely(ret != 0))
 258		pr_err("failed to unlock %s return %d\n", res->name, ret);
 259	else
 260		wait_event(res->sync_locking, res->sync_locking_done);
 261
 262	kfree(res->name);
 263	kfree(res->lksb.sb_lvbptr);
 264	kfree(res);
 265}
 266
 267static void add_resync_info(struct dlm_lock_resource *lockres,
 268			    sector_t lo, sector_t hi)
 269{
 270	struct resync_info *ri;
 271
 272	ri = (struct resync_info *)lockres->lksb.sb_lvbptr;
 273	ri->lo = cpu_to_le64(lo);
 274	ri->hi = cpu_to_le64(hi);
 275}
 276
 277static int read_resync_info(struct mddev *mddev,
 278			    struct dlm_lock_resource *lockres)
 279{
 280	struct resync_info ri;
 281	struct md_cluster_info *cinfo = mddev->cluster_info;
 282	int ret = 0;
 283
 284	dlm_lock_sync(lockres, DLM_LOCK_CR);
 285	memcpy(&ri, lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
 286	if (le64_to_cpu(ri.hi) > 0) {
 287		cinfo->suspend_hi = le64_to_cpu(ri.hi);
 288		cinfo->suspend_lo = le64_to_cpu(ri.lo);
 289		ret = 1;
 290	}
 291	dlm_unlock_sync(lockres);
 292	return ret;
 293}
 294
 295static void recover_bitmaps(struct md_thread *thread)
 296{
 297	struct mddev *mddev = thread->mddev;
 298	struct md_cluster_info *cinfo = mddev->cluster_info;
 299	struct dlm_lock_resource *bm_lockres;
 300	char str[64];
 301	int slot, ret;
 302	sector_t lo, hi;
 303
 304	while (cinfo->recovery_map) {
 305		slot = fls64((u64)cinfo->recovery_map) - 1;
 306
 307		snprintf(str, 64, "bitmap%04d", slot);
 308		bm_lockres = lockres_init(mddev, str, NULL, 1);
 309		if (!bm_lockres) {
 310			pr_err("md-cluster: Cannot initialize bitmaps\n");
 311			goto clear_bit;
 312		}
 313
 314		ret = dlm_lock_sync_interruptible(bm_lockres, DLM_LOCK_PW, mddev);
 315		if (ret) {
 316			pr_err("md-cluster: Could not DLM lock %s: %d\n",
 317					str, ret);
 318			goto clear_bit;
 319		}
 320		ret = mddev->bitmap_ops->copy_from_slot(mddev, slot, &lo, &hi, true);
 321		if (ret) {
 322			pr_err("md-cluster: Could not copy data from bitmap %d\n", slot);
 323			goto clear_bit;
 324		}
 325
 326		/* Clear suspend_area associated with the bitmap */
 327		spin_lock_irq(&cinfo->suspend_lock);
 328		cinfo->suspend_hi = 0;
 329		cinfo->suspend_lo = 0;
 330		cinfo->suspend_from = -1;
 331		spin_unlock_irq(&cinfo->suspend_lock);
 332
 333		/* Kick off a reshape if needed */
 334		if (test_bit(MD_RESYNCING_REMOTE, &mddev->recovery) &&
 335		    test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
 336		    mddev->reshape_position != MaxSector)
 337			md_wakeup_thread(mddev->sync_thread);
 338
 339		if (hi > 0) {
 340			if (lo < mddev->recovery_cp)
 341				mddev->recovery_cp = lo;
 342			/* wake up thread to continue resync in case resync
 343			 * is not finished */
 344			if (mddev->recovery_cp != MaxSector) {
 345				/*
 346				 * clear the REMOTE flag since we will launch
 347				 * resync thread in current node.
 348				 */
 349				clear_bit(MD_RESYNCING_REMOTE,
 350					  &mddev->recovery);
 351				set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 352				md_wakeup_thread(mddev->thread);
 353			}
 354		}
 355clear_bit:
 356		lockres_free(bm_lockres);
 357		clear_bit(slot, &cinfo->recovery_map);
 358	}
 359}
 360
 361static void recover_prep(void *arg)
 362{
 363	struct mddev *mddev = arg;
 364	struct md_cluster_info *cinfo = mddev->cluster_info;
 365	set_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state);
 366}
 367
 368static void __recover_slot(struct mddev *mddev, int slot)
 369{
 370	struct md_cluster_info *cinfo = mddev->cluster_info;
 371
 372	set_bit(slot, &cinfo->recovery_map);
 373	if (!cinfo->recovery_thread) {
 374		rcu_assign_pointer(cinfo->recovery_thread,
 375			md_register_thread(recover_bitmaps, mddev, "recover"));
 376		if (!cinfo->recovery_thread) {
 377			pr_warn("md-cluster: Could not create recovery thread\n");
 378			return;
 379		}
 380	}
 381	md_wakeup_thread(cinfo->recovery_thread);
 382}
 383
 384static void recover_slot(void *arg, struct dlm_slot *slot)
 385{
 386	struct mddev *mddev = arg;
 387	struct md_cluster_info *cinfo = mddev->cluster_info;
 388
 389	pr_info("md-cluster: %s Node %d/%d down. My slot: %d. Initiating recovery.\n",
 390			mddev->bitmap_info.cluster_name,
 391			slot->nodeid, slot->slot,
 392			cinfo->slot_number);
 393	/* deduct one since dlm slot starts from one while the num of
 394	 * cluster-md begins with 0 */
 395	__recover_slot(mddev, slot->slot - 1);
 396}
 397
 398static void recover_done(void *arg, struct dlm_slot *slots,
 399		int num_slots, int our_slot,
 400		uint32_t generation)
 401{
 402	struct mddev *mddev = arg;
 403	struct md_cluster_info *cinfo = mddev->cluster_info;
 404
 405	cinfo->slot_number = our_slot;
 406	/* completion is only need to be complete when node join cluster,
 407	 * it doesn't need to run during another node's failure */
 408	if (test_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state)) {
 409		complete(&cinfo->completion);
 410		clear_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state);
 411	}
 412	clear_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state);
 413}
 414
 415/* the ops is called when node join the cluster, and do lock recovery
 416 * if node failure occurs */
 417static const struct dlm_lockspace_ops md_ls_ops = {
 418	.recover_prep = recover_prep,
 419	.recover_slot = recover_slot,
 420	.recover_done = recover_done,
 421};
 422
 423/*
 424 * The BAST function for the ack lock resource
 425 * This function wakes up the receive thread in
 426 * order to receive and process the message.
 427 */
 428static void ack_bast(void *arg, int mode)
 429{
 430	struct dlm_lock_resource *res = arg;
 431	struct md_cluster_info *cinfo = res->mddev->cluster_info;
 432
 433	if (mode == DLM_LOCK_EX) {
 434		if (test_bit(MD_CLUSTER_ALREADY_IN_CLUSTER, &cinfo->state))
 435			md_wakeup_thread(cinfo->recv_thread);
 436		else
 437			set_bit(MD_CLUSTER_PENDING_RECV_EVENT, &cinfo->state);
 438	}
 439}
 440
 441static void remove_suspend_info(struct mddev *mddev, int slot)
 442{
 443	struct md_cluster_info *cinfo = mddev->cluster_info;
 444	mddev->pers->quiesce(mddev, 1);
 445	spin_lock_irq(&cinfo->suspend_lock);
 446	cinfo->suspend_hi = 0;
 447	cinfo->suspend_lo = 0;
 448	spin_unlock_irq(&cinfo->suspend_lock);
 449	mddev->pers->quiesce(mddev, 0);
 450}
 451
 452static void process_suspend_info(struct mddev *mddev,
 453		int slot, sector_t lo, sector_t hi)
 454{
 455	struct md_cluster_info *cinfo = mddev->cluster_info;
 456	struct mdp_superblock_1 *sb = NULL;
 457	struct md_rdev *rdev;
 458
 459	if (!hi) {
 460		/*
 461		 * clear the REMOTE flag since resync or recovery is finished
 462		 * in remote node.
 463		 */
 464		clear_bit(MD_RESYNCING_REMOTE, &mddev->recovery);
 465		remove_suspend_info(mddev, slot);
 466		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 467		clear_bit(MD_CLUSTER_WAITING_FOR_SYNC, &cinfo->state);
 468		md_wakeup_thread(mddev->thread);
 469		return;
 470	}
 471
 472	rdev_for_each(rdev, mddev)
 473		if (rdev->raid_disk > -1 && !test_bit(Faulty, &rdev->flags)) {
 474			sb = page_address(rdev->sb_page);
 475			break;
 476		}
 477
 478	/*
 479	 * The bitmaps are not same for different nodes
 480	 * if RESYNCING is happening in one node, then
 481	 * the node which received the RESYNCING message
 482	 * probably will perform resync with the region
 483	 * [lo, hi] again, so we could reduce resync time
 484	 * a lot if we can ensure that the bitmaps among
 485	 * different nodes are match up well.
 486	 *
 487	 * sync_low/hi is used to record the region which
 488	 * arrived in the previous RESYNCING message,
 489	 *
 490	 * Call md_bitmap_sync_with_cluster to clear NEEDED_MASK
 491	 * and set RESYNC_MASK since  resync thread is running
 492	 * in another node, so we don't need to do the resync
 493	 * again with the same section.
 494	 *
 495	 * Skip md_bitmap_sync_with_cluster in case reshape
 496	 * happening, because reshaping region is small and
 497	 * we don't want to trigger lots of WARN.
 498	 */
 499	if (sb && !(le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE))
 500		mddev->bitmap_ops->sync_with_cluster(mddev, cinfo->sync_low,
 501						     cinfo->sync_hi, lo, hi);
 502	cinfo->sync_low = lo;
 503	cinfo->sync_hi = hi;
 504
 505	mddev->pers->quiesce(mddev, 1);
 506	spin_lock_irq(&cinfo->suspend_lock);
 507	cinfo->suspend_from = slot;
 508	cinfo->suspend_lo = lo;
 509	cinfo->suspend_hi = hi;
 510	spin_unlock_irq(&cinfo->suspend_lock);
 511	mddev->pers->quiesce(mddev, 0);
 512}
 513
 514static int process_add_new_disk(struct mddev *mddev, struct cluster_msg *cmsg)
 515{
 516	char disk_uuid[64];
 517	struct md_cluster_info *cinfo = mddev->cluster_info;
 518	char event_name[] = "EVENT=ADD_DEVICE";
 519	char raid_slot[16];
 520	char *envp[] = {event_name, disk_uuid, raid_slot, NULL};
 521	int len;
 522	int res = 0;
 523
 524	len = snprintf(disk_uuid, 64, "DEVICE_UUID=");
 525	sprintf(disk_uuid + len, "%pU", cmsg->uuid);
 526	snprintf(raid_slot, 16, "RAID_DISK=%d", le32_to_cpu(cmsg->raid_slot));
 527	pr_info("%s:%d Sending kobject change with %s and %s\n", __func__, __LINE__, disk_uuid, raid_slot);
 528	init_completion(&cinfo->newdisk_completion);
 529	set_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state);
 530	kobject_uevent_env(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE, envp);
 531	if (!wait_for_completion_timeout(&cinfo->newdisk_completion,
 532					NEW_DEV_TIMEOUT)) {
 533		pr_err("md-cluster(%s:%d): timeout on a new disk adding\n",
 534			__func__, __LINE__);
 535		res = -1;
 536	}
 537	clear_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state);
 538	set_bit(MD_CLUSTER_WAITING_FOR_SYNC, &cinfo->state);
 539	return res;
 540}
 541
 542
 543static void process_metadata_update(struct mddev *mddev, struct cluster_msg *msg)
 544{
 545	int got_lock = 0;
 546	struct md_thread *thread;
 547	struct md_cluster_info *cinfo = mddev->cluster_info;
 548	mddev->good_device_nr = le32_to_cpu(msg->raid_slot);
 549
 550	dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
 551
 552	/* daemaon thread must exist */
 553	thread = rcu_dereference_protected(mddev->thread, true);
 554	wait_event(thread->wqueue,
 555		   (got_lock = mddev_trylock(mddev)) ||
 556		    test_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state));
 557	md_reload_sb(mddev, mddev->good_device_nr);
 558	if (got_lock)
 559		mddev_unlock(mddev);
 560}
 561
 562static void process_remove_disk(struct mddev *mddev, struct cluster_msg *msg)
 563{
 564	struct md_rdev *rdev;
 565
 566	rcu_read_lock();
 567	rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));
 568	if (rdev) {
 569		set_bit(ClusterRemove, &rdev->flags);
 570		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 571		md_wakeup_thread(mddev->thread);
 572	}
 573	else
 574		pr_warn("%s: %d Could not find disk(%d) to REMOVE\n",
 575			__func__, __LINE__, le32_to_cpu(msg->raid_slot));
 576	rcu_read_unlock();
 577}
 578
 579static void process_readd_disk(struct mddev *mddev, struct cluster_msg *msg)
 580{
 581	struct md_rdev *rdev;
 582
 583	rcu_read_lock();
 584	rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));
 585	if (rdev && test_bit(Faulty, &rdev->flags))
 586		clear_bit(Faulty, &rdev->flags);
 587	else
 588		pr_warn("%s: %d Could not find disk(%d) which is faulty",
 589			__func__, __LINE__, le32_to_cpu(msg->raid_slot));
 590	rcu_read_unlock();
 591}
 592
 593static int process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
 594{
 595	int ret = 0;
 596
 597	if (WARN(mddev->cluster_info->slot_number - 1 == le32_to_cpu(msg->slot),
 598		"node %d received its own msg\n", le32_to_cpu(msg->slot)))
 599		return -1;
 600	switch (le32_to_cpu(msg->type)) {
 601	case METADATA_UPDATED:
 602		process_metadata_update(mddev, msg);
 603		break;
 604	case CHANGE_CAPACITY:
 605		set_capacity_and_notify(mddev->gendisk, mddev->array_sectors);
 606		break;
 607	case RESYNCING_START:
 608		clear_bit(MD_CLUSTER_WAITING_FOR_SYNC, &mddev->cluster_info->state);
 609		break;
 610	case RESYNCING:
 611		set_bit(MD_RESYNCING_REMOTE, &mddev->recovery);
 612		process_suspend_info(mddev, le32_to_cpu(msg->slot),
 613				     le64_to_cpu(msg->low),
 614				     le64_to_cpu(msg->high));
 615		break;
 616	case NEWDISK:
 617		if (process_add_new_disk(mddev, msg))
 618			ret = -1;
 619		break;
 620	case REMOVE:
 621		process_remove_disk(mddev, msg);
 622		break;
 623	case RE_ADD:
 624		process_readd_disk(mddev, msg);
 625		break;
 626	case BITMAP_NEEDS_SYNC:
 627		__recover_slot(mddev, le32_to_cpu(msg->slot));
 628		break;
 629	case BITMAP_RESIZE:
 630		if (le64_to_cpu(msg->high) != mddev->pers->size(mddev, 0, 0))
 631			ret = mddev->bitmap_ops->resize(mddev,
 632							le64_to_cpu(msg->high),
 633							0, false);
 634		break;
 635	default:
 636		ret = -1;
 637		pr_warn("%s:%d Received unknown message from %d\n",
 638			__func__, __LINE__, msg->slot);
 639	}
 640	return ret;
 641}
 642
 643/*
 644 * thread for receiving message
 645 */
 646static void recv_daemon(struct md_thread *thread)
 647{
 648	struct md_cluster_info *cinfo = thread->mddev->cluster_info;
 649	struct dlm_lock_resource *ack_lockres = cinfo->ack_lockres;
 650	struct dlm_lock_resource *message_lockres = cinfo->message_lockres;
 651	struct cluster_msg msg;
 652	int ret;
 653
 654	mutex_lock(&cinfo->recv_mutex);
 655	/*get CR on Message*/
 656	if (dlm_lock_sync(message_lockres, DLM_LOCK_CR)) {
 657		pr_err("md/raid1:failed to get CR on MESSAGE\n");
 658		mutex_unlock(&cinfo->recv_mutex);
 659		return;
 660	}
 661
 662	/* read lvb and wake up thread to process this message_lockres */
 663	memcpy(&msg, message_lockres->lksb.sb_lvbptr, sizeof(struct cluster_msg));
 664	ret = process_recvd_msg(thread->mddev, &msg);
 665	if (ret)
 666		goto out;
 667
 668	/*release CR on ack_lockres*/
 669	ret = dlm_unlock_sync(ack_lockres);
 670	if (unlikely(ret != 0))
 671		pr_info("unlock ack failed return %d\n", ret);
 672	/*up-convert to PR on message_lockres*/
 673	ret = dlm_lock_sync(message_lockres, DLM_LOCK_PR);
 674	if (unlikely(ret != 0))
 675		pr_info("lock PR on msg failed return %d\n", ret);
 676	/*get CR on ack_lockres again*/
 677	ret = dlm_lock_sync(ack_lockres, DLM_LOCK_CR);
 678	if (unlikely(ret != 0))
 679		pr_info("lock CR on ack failed return %d\n", ret);
 680out:
 681	/*release CR on message_lockres*/
 682	ret = dlm_unlock_sync(message_lockres);
 683	if (unlikely(ret != 0))
 684		pr_info("unlock msg failed return %d\n", ret);
 685	mutex_unlock(&cinfo->recv_mutex);
 686}
 687
 688/* lock_token()
 689 * Takes the lock on the TOKEN lock resource so no other
 690 * node can communicate while the operation is underway.
 691 */
 692static int lock_token(struct md_cluster_info *cinfo)
 693{
 694	int error;
 695
 696	error = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
 697	if (error) {
 698		pr_err("md-cluster(%s:%d): failed to get EX on TOKEN (%d)\n",
 699				__func__, __LINE__, error);
 700	} else {
 701		/* Lock the receive sequence */
 702		mutex_lock(&cinfo->recv_mutex);
 703	}
 704	return error;
 705}
 706
 707/* lock_comm()
 708 * Sets the MD_CLUSTER_SEND_LOCK bit to lock the send channel.
 709 */
 710static int lock_comm(struct md_cluster_info *cinfo, bool mddev_locked)
 711{
 712	int rv, set_bit = 0;
 713	struct mddev *mddev = cinfo->mddev;
 714
 715	/*
 716	 * If resync thread run after raid1d thread, then process_metadata_update
 717	 * could not continue if raid1d held reconfig_mutex (and raid1d is blocked
 718	 * since another node already got EX on Token and waiting the EX of Ack),
 719	 * so let resync wake up thread in case flag is set.
 720	 */
 721	if (mddev_locked && !test_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
 722				      &cinfo->state)) {
 723		rv = test_and_set_bit_lock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
 724					      &cinfo->state);
 725		WARN_ON_ONCE(rv);
 726		md_wakeup_thread(mddev->thread);
 727		set_bit = 1;
 728	}
 729
 730	wait_event(cinfo->wait,
 731		   !test_and_set_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state));
 732	rv = lock_token(cinfo);
 733	if (set_bit)
 734		clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
 735	return rv;
 736}
 737
 738static void unlock_comm(struct md_cluster_info *cinfo)
 739{
 740	WARN_ON(cinfo->token_lockres->mode != DLM_LOCK_EX);
 741	mutex_unlock(&cinfo->recv_mutex);
 742	dlm_unlock_sync(cinfo->token_lockres);
 743	clear_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state);
 744	wake_up(&cinfo->wait);
 745}
 746
 747/* __sendmsg()
 748 * This function performs the actual sending of the message. This function is
 749 * usually called after performing the encompassing operation
 750 * The function:
 751 * 1. Grabs the message lockresource in EX mode
 752 * 2. Copies the message to the message LVB
 753 * 3. Downconverts message lockresource to CW
 754 * 4. Upconverts ack lock resource from CR to EX. This forces the BAST on other nodes
 755 *    and the other nodes read the message. The thread will wait here until all other
 756 *    nodes have released ack lock resource.
 757 * 5. Downconvert ack lockresource to CR
 758 */
 759static int __sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg)
 760{
 761	int error, unlock_error;
 762	int slot = cinfo->slot_number - 1;
 763
 764	cmsg->slot = cpu_to_le32(slot);
 765	/*get EX on Message*/
 766	error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_EX);
 767	if (error) {
 768		pr_err("md-cluster: failed to get EX on MESSAGE (%d)\n", error);
 769		return error;
 770	}
 771
 772	memcpy(cinfo->message_lockres->lksb.sb_lvbptr, (void *)cmsg,
 773			sizeof(struct cluster_msg));
 774	/*down-convert EX to CW on Message*/
 775	error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_CW);
 776	if (error) {
 777		pr_err("md-cluster: failed to convert EX to CW on MESSAGE(%d)\n",
 778				error);
 779		goto failed_ack;
 780	}
 781
 782	/*up-convert CR to EX on Ack*/
 783	error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_EX);
 784	if (error) {
 785		pr_err("md-cluster: failed to convert CR to EX on ACK(%d)\n",
 786				error);
 787		goto failed_ack;
 788	}
 789
 790	/*down-convert EX to CR on Ack*/
 791	error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR);
 792	if (error) {
 793		pr_err("md-cluster: failed to convert EX to CR on ACK(%d)\n",
 794				error);
 795		goto failed_ack;
 796	}
 797
 798failed_ack:
 799	while ((unlock_error = dlm_unlock_sync(cinfo->message_lockres)))
 800		pr_err("md-cluster: failed convert to NL on MESSAGE(%d)\n",
 801			unlock_error);
 802
 803	return error;
 804}
 805
 806static int sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg,
 807		   bool mddev_locked)
 808{
 809	int ret;
 810
 811	ret = lock_comm(cinfo, mddev_locked);
 812	if (!ret) {
 813		ret = __sendmsg(cinfo, cmsg);
 814		unlock_comm(cinfo);
 815	}
 816	return ret;
 817}
 818
 819static int gather_all_resync_info(struct mddev *mddev, int total_slots)
 820{
 821	struct md_cluster_info *cinfo = mddev->cluster_info;
 822	int i, ret = 0;
 823	struct dlm_lock_resource *bm_lockres;
 824	char str[64];
 825	sector_t lo, hi;
 826
 827
 828	for (i = 0; i < total_slots; i++) {
 829		memset(str, '\0', 64);
 830		snprintf(str, 64, "bitmap%04d", i);
 831		bm_lockres = lockres_init(mddev, str, NULL, 1);
 832		if (!bm_lockres)
 833			return -ENOMEM;
 834		if (i == (cinfo->slot_number - 1)) {
 835			lockres_free(bm_lockres);
 836			continue;
 837		}
 838
 839		bm_lockres->flags |= DLM_LKF_NOQUEUE;
 840		ret = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
 841		if (ret == -EAGAIN) {
 842			if (read_resync_info(mddev, bm_lockres)) {
 843				pr_info("%s:%d Resync[%llu..%llu] in progress on %d\n",
 844						__func__, __LINE__,
 845					(unsigned long long) cinfo->suspend_lo,
 846					(unsigned long long) cinfo->suspend_hi,
 847					i);
 848				cinfo->suspend_from = i;
 849			}
 850			ret = 0;
 851			lockres_free(bm_lockres);
 852			continue;
 853		}
 854		if (ret) {
 855			lockres_free(bm_lockres);
 856			goto out;
 857		}
 858
 859		/* Read the disk bitmap sb and check if it needs recovery */
 860		ret = mddev->bitmap_ops->copy_from_slot(mddev, i, &lo, &hi, false);
 861		if (ret) {
 862			pr_warn("md-cluster: Could not gather bitmaps from slot %d", i);
 863			lockres_free(bm_lockres);
 864			continue;
 865		}
 866		if ((hi > 0) && (lo < mddev->recovery_cp)) {
 867			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 868			mddev->recovery_cp = lo;
 869			md_check_recovery(mddev);
 870		}
 871
 872		lockres_free(bm_lockres);
 873	}
 874out:
 875	return ret;
 876}
 877
 878static int join(struct mddev *mddev, int nodes)
 879{
 880	struct md_cluster_info *cinfo;
 881	int ret, ops_rv;
 882	char str[64];
 883
 884	cinfo = kzalloc(sizeof(struct md_cluster_info), GFP_KERNEL);
 885	if (!cinfo)
 886		return -ENOMEM;
 887
 888	INIT_LIST_HEAD(&cinfo->suspend_list);
 889	spin_lock_init(&cinfo->suspend_lock);
 890	init_completion(&cinfo->completion);
 891	set_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state);
 892	init_waitqueue_head(&cinfo->wait);
 893	mutex_init(&cinfo->recv_mutex);
 894
 895	mddev->cluster_info = cinfo;
 896	cinfo->mddev = mddev;
 897
 898	memset(str, 0, 64);
 899	sprintf(str, "%pU", mddev->uuid);
 900	ret = dlm_new_lockspace(str, mddev->bitmap_info.cluster_name,
 901				DLM_LSFL_SOFTIRQ, LVB_SIZE, &md_ls_ops, mddev,
 902				&ops_rv, &cinfo->lockspace);
 903	if (ret)
 904		goto err;
 905	wait_for_completion(&cinfo->completion);
 906	if (nodes < cinfo->slot_number) {
 907		pr_err("md-cluster: Slot allotted(%d) is greater than available slots(%d).",
 908			cinfo->slot_number, nodes);
 909		ret = -ERANGE;
 910		goto err;
 911	}
 912	/* Initiate the communication resources */
 913	ret = -ENOMEM;
 914	rcu_assign_pointer(cinfo->recv_thread,
 915			md_register_thread(recv_daemon, mddev, "cluster_recv"));
 916	if (!cinfo->recv_thread) {
 917		pr_err("md-cluster: cannot allocate memory for recv_thread!\n");
 918		goto err;
 919	}
 920	cinfo->message_lockres = lockres_init(mddev, "message", NULL, 1);
 921	if (!cinfo->message_lockres)
 922		goto err;
 923	cinfo->token_lockres = lockres_init(mddev, "token", NULL, 0);
 924	if (!cinfo->token_lockres)
 925		goto err;
 926	cinfo->no_new_dev_lockres = lockres_init(mddev, "no-new-dev", NULL, 0);
 927	if (!cinfo->no_new_dev_lockres)
 928		goto err;
 929
 930	ret = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
 931	if (ret) {
 932		ret = -EAGAIN;
 933		pr_err("md-cluster: can't join cluster to avoid lock issue\n");
 934		goto err;
 935	}
 936	cinfo->ack_lockres = lockres_init(mddev, "ack", ack_bast, 0);
 937	if (!cinfo->ack_lockres) {
 938		ret = -ENOMEM;
 939		goto err;
 940	}
 941	/* get sync CR lock on ACK. */
 942	if (dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR))
 943		pr_err("md-cluster: failed to get a sync CR lock on ACK!(%d)\n",
 944				ret);
 945	dlm_unlock_sync(cinfo->token_lockres);
 946	/* get sync CR lock on no-new-dev. */
 947	if (dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR))
 948		pr_err("md-cluster: failed to get a sync CR lock on no-new-dev!(%d)\n", ret);
 949
 950
 951	pr_info("md-cluster: Joined cluster %s slot %d\n", str, cinfo->slot_number);
 952	snprintf(str, 64, "bitmap%04d", cinfo->slot_number - 1);
 953	cinfo->bitmap_lockres = lockres_init(mddev, str, NULL, 1);
 954	if (!cinfo->bitmap_lockres) {
 955		ret = -ENOMEM;
 956		goto err;
 957	}
 958	if (dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW)) {
 959		pr_err("Failed to get bitmap lock\n");
 960		ret = -EINVAL;
 961		goto err;
 962	}
 963
 964	cinfo->resync_lockres = lockres_init(mddev, "resync", NULL, 0);
 965	if (!cinfo->resync_lockres) {
 966		ret = -ENOMEM;
 967		goto err;
 968	}
 969
 970	return 0;
 971err:
 972	set_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
 973	md_unregister_thread(mddev, &cinfo->recovery_thread);
 974	md_unregister_thread(mddev, &cinfo->recv_thread);
 975	lockres_free(cinfo->message_lockres);
 976	lockres_free(cinfo->token_lockres);
 977	lockres_free(cinfo->ack_lockres);
 978	lockres_free(cinfo->no_new_dev_lockres);
 979	lockres_free(cinfo->resync_lockres);
 980	lockres_free(cinfo->bitmap_lockres);
 981	if (cinfo->lockspace)
 982		dlm_release_lockspace(cinfo->lockspace, 2);
 983	mddev->cluster_info = NULL;
 984	kfree(cinfo);
 985	return ret;
 986}
 987
 988static void load_bitmaps(struct mddev *mddev, int total_slots)
 989{
 990	struct md_cluster_info *cinfo = mddev->cluster_info;
 991
 992	/* load all the node's bitmap info for resync */
 993	if (gather_all_resync_info(mddev, total_slots))
 994		pr_err("md-cluster: failed to gather all resyn infos\n");
 995	set_bit(MD_CLUSTER_ALREADY_IN_CLUSTER, &cinfo->state);
 996	/* wake up recv thread in case something need to be handled */
 997	if (test_and_clear_bit(MD_CLUSTER_PENDING_RECV_EVENT, &cinfo->state))
 998		md_wakeup_thread(cinfo->recv_thread);
 999}
1000
1001static void resync_bitmap(struct mddev *mddev)
1002{
1003	struct md_cluster_info *cinfo = mddev->cluster_info;
1004	struct cluster_msg cmsg = {0};
1005	int err;
1006
1007	cmsg.type = cpu_to_le32(BITMAP_NEEDS_SYNC);
1008	err = sendmsg(cinfo, &cmsg, 1);
1009	if (err)
1010		pr_err("%s:%d: failed to send BITMAP_NEEDS_SYNC message (%d)\n",
1011			__func__, __LINE__, err);
1012}
1013
1014static void unlock_all_bitmaps(struct mddev *mddev);
1015static int leave(struct mddev *mddev)
1016{
1017	struct md_cluster_info *cinfo = mddev->cluster_info;
1018
1019	if (!cinfo)
1020		return 0;
1021
1022	/*
1023	 * BITMAP_NEEDS_SYNC message should be sent when node
1024	 * is leaving the cluster with dirty bitmap, also we
1025	 * can only deliver it when dlm connection is available.
1026	 *
1027	 * Also, we should send BITMAP_NEEDS_SYNC message in
1028	 * case reshaping is interrupted.
1029	 */
1030	if ((cinfo->slot_number > 0 && mddev->recovery_cp != MaxSector) ||
1031	    (mddev->reshape_position != MaxSector &&
1032	     test_bit(MD_CLOSING, &mddev->flags)))
1033		resync_bitmap(mddev);
1034
1035	set_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
1036	md_unregister_thread(mddev, &cinfo->recovery_thread);
1037	md_unregister_thread(mddev, &cinfo->recv_thread);
1038	lockres_free(cinfo->message_lockres);
1039	lockres_free(cinfo->token_lockres);
1040	lockres_free(cinfo->ack_lockres);
1041	lockres_free(cinfo->no_new_dev_lockres);
1042	lockres_free(cinfo->resync_lockres);
1043	lockres_free(cinfo->bitmap_lockres);
1044	unlock_all_bitmaps(mddev);
1045	dlm_release_lockspace(cinfo->lockspace, 2);
1046	kfree(cinfo);
1047	return 0;
1048}
1049
1050/* slot_number(): Returns the MD slot number to use
1051 * DLM starts the slot numbers from 1, wheras cluster-md
1052 * wants the number to be from zero, so we deduct one
1053 */
1054static int slot_number(struct mddev *mddev)
1055{
1056	struct md_cluster_info *cinfo = mddev->cluster_info;
1057
1058	return cinfo->slot_number - 1;
1059}
1060
1061/*
1062 * Check if the communication is already locked, else lock the communication
1063 * channel.
1064 * If it is already locked, token is in EX mode, and hence lock_token()
1065 * should not be called.
1066 */
1067static int metadata_update_start(struct mddev *mddev)
1068{
1069	struct md_cluster_info *cinfo = mddev->cluster_info;
1070	int ret;
1071
1072	/*
1073	 * metadata_update_start is always called with the protection of
1074	 * reconfig_mutex, so set WAITING_FOR_TOKEN here.
1075	 */
1076	ret = test_and_set_bit_lock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
1077				    &cinfo->state);
1078	WARN_ON_ONCE(ret);
1079	md_wakeup_thread(mddev->thread);
1080
1081	wait_event(cinfo->wait,
1082		   !test_and_set_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state) ||
1083		   test_and_clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state));
1084
1085	/* If token is already locked, return 0 */
1086	if (cinfo->token_lockres->mode == DLM_LOCK_EX) {
1087		clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
1088		return 0;
1089	}
1090
1091	ret = lock_token(cinfo);
1092	clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
1093	return ret;
1094}
1095
1096static int metadata_update_finish(struct mddev *mddev)
1097{
1098	struct md_cluster_info *cinfo = mddev->cluster_info;
1099	struct cluster_msg cmsg;
1100	struct md_rdev *rdev;
1101	int ret = 0;
1102	int raid_slot = -1;
1103
1104	memset(&cmsg, 0, sizeof(cmsg));
1105	cmsg.type = cpu_to_le32(METADATA_UPDATED);
1106	/* Pick up a good active device number to send.
1107	 */
1108	rdev_for_each(rdev, mddev)
1109		if (rdev->raid_disk > -1 && !test_bit(Faulty, &rdev->flags)) {
1110			raid_slot = rdev->desc_nr;
1111			break;
1112		}
1113	if (raid_slot >= 0) {
1114		cmsg.raid_slot = cpu_to_le32(raid_slot);
1115		ret = __sendmsg(cinfo, &cmsg);
1116	} else
1117		pr_warn("md-cluster: No good device id found to send\n");
1118	clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1119	unlock_comm(cinfo);
1120	return ret;
1121}
1122
1123static void metadata_update_cancel(struct mddev *mddev)
1124{
1125	struct md_cluster_info *cinfo = mddev->cluster_info;
1126	clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1127	unlock_comm(cinfo);
1128}
1129
1130static int update_bitmap_size(struct mddev *mddev, sector_t size)
1131{
1132	struct md_cluster_info *cinfo = mddev->cluster_info;
1133	struct cluster_msg cmsg = {0};
1134	int ret;
1135
1136	cmsg.type = cpu_to_le32(BITMAP_RESIZE);
1137	cmsg.high = cpu_to_le64(size);
1138	ret = sendmsg(cinfo, &cmsg, 0);
1139	if (ret)
1140		pr_err("%s:%d: failed to send BITMAP_RESIZE message (%d)\n",
1141			__func__, __LINE__, ret);
1142	return ret;
1143}
1144
1145static int resize_bitmaps(struct mddev *mddev, sector_t newsize, sector_t oldsize)
1146{
1147	void *bitmap = mddev->bitmap;
1148	struct md_bitmap_stats stats;
1149	unsigned long my_pages;
1150	int i, rv;
1151
1152	rv = mddev->bitmap_ops->get_stats(bitmap, &stats);
1153	if (rv)
1154		return rv;
1155
1156	my_pages = stats.pages;
1157	/*
1158	 * We need to ensure all the nodes can grow to a larger
1159	 * bitmap size before make the reshaping.
1160	 */
1161	rv = update_bitmap_size(mddev, newsize);
1162	if (rv)
1163		return rv;
1164
1165	for (i = 0; i < mddev->bitmap_info.nodes; i++) {
1166		struct dlm_lock_resource *bm_lockres;
1167		char str[64];
1168
1169		if (i == md_cluster_ops->slot_number(mddev))
1170			continue;
1171
1172		bitmap = mddev->bitmap_ops->get_from_slot(mddev, i);
1173		if (IS_ERR(bitmap)) {
1174			pr_err("can't get bitmap from slot %d\n", i);
1175			bitmap = NULL;
1176			goto out;
1177		}
1178
1179		rv = mddev->bitmap_ops->get_stats(bitmap, &stats);
1180		if (rv)
1181			goto out;
1182		/*
1183		 * If we can hold the bitmap lock of one node then
1184		 * the slot is not occupied, update the pages.
1185		 */
1186		snprintf(str, 64, "bitmap%04d", i);
1187		bm_lockres = lockres_init(mddev, str, NULL, 1);
1188		if (!bm_lockres) {
1189			pr_err("Cannot initialize %s lock\n", str);
1190			goto out;
1191		}
1192		bm_lockres->flags |= DLM_LKF_NOQUEUE;
1193		rv = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
1194		if (!rv)
1195			mddev->bitmap_ops->set_pages(bitmap, my_pages);
1196		lockres_free(bm_lockres);
1197
1198		if (my_pages != stats.pages)
1199			/*
1200			 * Let's revert the bitmap size if one node
1201			 * can't resize bitmap
1202			 */
1203			goto out;
1204		mddev->bitmap_ops->free(bitmap);
1205	}
1206
1207	return 0;
1208out:
1209	mddev->bitmap_ops->free(bitmap);
1210	update_bitmap_size(mddev, oldsize);
1211	return -1;
1212}
1213
1214/*
1215 * return 0 if all the bitmaps have the same sync_size
1216 */
1217static int cluster_check_sync_size(struct mddev *mddev)
1218{
1219	int current_slot = md_cluster_ops->slot_number(mddev);
1220	int node_num = mddev->bitmap_info.nodes;
1221	struct dlm_lock_resource *bm_lockres;
1222	struct md_bitmap_stats stats;
1223	void *bitmap = mddev->bitmap;
1224	unsigned long sync_size = 0;
1225	unsigned long my_sync_size;
1226	char str[64];
1227	int i, rv;
1228
1229	rv = mddev->bitmap_ops->get_stats(bitmap, &stats);
1230	if (rv)
1231		return rv;
1232
1233	my_sync_size = stats.sync_size;
1234
1235	for (i = 0; i < node_num; i++) {
1236		if (i == current_slot)
1237			continue;
1238
1239		bitmap = mddev->bitmap_ops->get_from_slot(mddev, i);
1240		if (IS_ERR(bitmap)) {
1241			pr_err("can't get bitmap from slot %d\n", i);
1242			return -1;
1243		}
1244
1245		/*
1246		 * If we can hold the bitmap lock of one node then
1247		 * the slot is not occupied, update the sb.
1248		 */
1249		snprintf(str, 64, "bitmap%04d", i);
1250		bm_lockres = lockres_init(mddev, str, NULL, 1);
1251		if (!bm_lockres) {
1252			pr_err("md-cluster: Cannot initialize %s\n", str);
1253			mddev->bitmap_ops->free(bitmap);
1254			return -1;
1255		}
1256		bm_lockres->flags |= DLM_LKF_NOQUEUE;
1257		rv = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
1258		if (!rv)
1259			mddev->bitmap_ops->update_sb(bitmap);
1260		lockres_free(bm_lockres);
1261
1262		rv = mddev->bitmap_ops->get_stats(bitmap, &stats);
1263		if (rv) {
1264			mddev->bitmap_ops->free(bitmap);
1265			return rv;
1266		}
1267
1268		if (sync_size == 0) {
1269			sync_size = stats.sync_size;
1270		} else if (sync_size != stats.sync_size) {
1271			mddev->bitmap_ops->free(bitmap);
1272			return -1;
1273		}
1274		mddev->bitmap_ops->free(bitmap);
1275	}
1276
1277	return (my_sync_size == sync_size) ? 0 : -1;
1278}
1279
1280/*
1281 * Update the size for cluster raid is a little more complex, we perform it
1282 * by the steps:
1283 * 1. hold token lock and update superblock in initiator node.
1284 * 2. send METADATA_UPDATED msg to other nodes.
1285 * 3. The initiator node continues to check each bitmap's sync_size, if all
1286 *    bitmaps have the same value of sync_size, then we can set capacity and
1287 *    let other nodes to perform it. If one node can't update sync_size
1288 *    accordingly, we need to revert to previous value.
1289 */
1290static void update_size(struct mddev *mddev, sector_t old_dev_sectors)
1291{
1292	struct md_cluster_info *cinfo = mddev->cluster_info;
1293	struct cluster_msg cmsg;
1294	struct md_rdev *rdev;
1295	int ret = 0;
1296	int raid_slot = -1;
1297
1298	md_update_sb(mddev, 1);
1299	if (lock_comm(cinfo, 1)) {
1300		pr_err("%s: lock_comm failed\n", __func__);
1301		return;
1302	}
1303
1304	memset(&cmsg, 0, sizeof(cmsg));
1305	cmsg.type = cpu_to_le32(METADATA_UPDATED);
1306	rdev_for_each(rdev, mddev)
1307		if (rdev->raid_disk >= 0 && !test_bit(Faulty, &rdev->flags)) {
1308			raid_slot = rdev->desc_nr;
1309			break;
1310		}
1311	if (raid_slot >= 0) {
1312		cmsg.raid_slot = cpu_to_le32(raid_slot);
1313		/*
1314		 * We can only change capiticy after all the nodes can do it,
1315		 * so need to wait after other nodes already received the msg
1316		 * and handled the change
1317		 */
1318		ret = __sendmsg(cinfo, &cmsg);
1319		if (ret) {
1320			pr_err("%s:%d: failed to send METADATA_UPDATED msg\n",
1321			       __func__, __LINE__);
1322			unlock_comm(cinfo);
1323			return;
1324		}
1325	} else {
1326		pr_err("md-cluster: No good device id found to send\n");
1327		unlock_comm(cinfo);
1328		return;
1329	}
1330
1331	/*
1332	 * check the sync_size from other node's bitmap, if sync_size
1333	 * have already updated in other nodes as expected, send an
1334	 * empty metadata msg to permit the change of capacity
1335	 */
1336	if (cluster_check_sync_size(mddev) == 0) {
1337		memset(&cmsg, 0, sizeof(cmsg));
1338		cmsg.type = cpu_to_le32(CHANGE_CAPACITY);
1339		ret = __sendmsg(cinfo, &cmsg);
1340		if (ret)
1341			pr_err("%s:%d: failed to send CHANGE_CAPACITY msg\n",
1342			       __func__, __LINE__);
1343		set_capacity_and_notify(mddev->gendisk, mddev->array_sectors);
1344	} else {
1345		/* revert to previous sectors */
1346		ret = mddev->pers->resize(mddev, old_dev_sectors);
1347		ret = __sendmsg(cinfo, &cmsg);
1348		if (ret)
1349			pr_err("%s:%d: failed to send METADATA_UPDATED msg\n",
1350			       __func__, __LINE__);
1351	}
1352	unlock_comm(cinfo);
1353}
1354
1355static int resync_start(struct mddev *mddev)
1356{
1357	struct md_cluster_info *cinfo = mddev->cluster_info;
1358	return dlm_lock_sync_interruptible(cinfo->resync_lockres, DLM_LOCK_EX, mddev);
1359}
1360
1361static void resync_info_get(struct mddev *mddev, sector_t *lo, sector_t *hi)
1362{
1363	struct md_cluster_info *cinfo = mddev->cluster_info;
1364
1365	spin_lock_irq(&cinfo->suspend_lock);
1366	*lo = cinfo->suspend_lo;
1367	*hi = cinfo->suspend_hi;
1368	spin_unlock_irq(&cinfo->suspend_lock);
1369}
1370
1371static int resync_status_get(struct mddev *mddev)
1372{
1373	struct md_cluster_info *cinfo = mddev->cluster_info;
1374
1375	return test_bit(MD_CLUSTER_WAITING_FOR_SYNC, &cinfo->state);
1376}
1377
1378static int resync_start_notify(struct mddev *mddev)
1379{
1380	struct md_cluster_info *cinfo = mddev->cluster_info;
1381	struct cluster_msg cmsg = {0};
1382
1383	cmsg.type = cpu_to_le32(RESYNCING_START);
1384
1385	return sendmsg(cinfo, &cmsg, 0);
1386}
1387
1388static int resync_info_update(struct mddev *mddev, sector_t lo, sector_t hi)
1389{
1390	struct md_cluster_info *cinfo = mddev->cluster_info;
1391	struct resync_info ri;
1392	struct cluster_msg cmsg = {0};
1393
1394	/* do not send zero again, if we have sent before */
1395	if (hi == 0) {
1396		memcpy(&ri, cinfo->bitmap_lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
1397		if (le64_to_cpu(ri.hi) == 0)
1398			return 0;
1399	}
1400
1401	add_resync_info(cinfo->bitmap_lockres, lo, hi);
1402	/* Re-acquire the lock to refresh LVB */
1403	dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW);
1404	cmsg.type = cpu_to_le32(RESYNCING);
1405	cmsg.low = cpu_to_le64(lo);
1406	cmsg.high = cpu_to_le64(hi);
1407
1408	/*
1409	 * mddev_lock is held if resync_info_update is called from
1410	 * resync_finish (md_reap_sync_thread -> resync_finish)
1411	 */
1412	if (lo == 0 && hi == 0)
1413		return sendmsg(cinfo, &cmsg, 1);
1414	else
1415		return sendmsg(cinfo, &cmsg, 0);
1416}
1417
1418static int resync_finish(struct mddev *mddev)
1419{
1420	struct md_cluster_info *cinfo = mddev->cluster_info;
1421	int ret = 0;
1422
1423	clear_bit(MD_RESYNCING_REMOTE, &mddev->recovery);
1424
1425	/*
1426	 * If resync thread is interrupted so we can't say resync is finished,
1427	 * another node will launch resync thread to continue.
1428	 */
1429	if (!test_bit(MD_CLOSING, &mddev->flags))
1430		ret = resync_info_update(mddev, 0, 0);
1431	dlm_unlock_sync(cinfo->resync_lockres);
1432	return ret;
1433}
1434
1435static int area_resyncing(struct mddev *mddev, int direction,
1436		sector_t lo, sector_t hi)
1437{
1438	struct md_cluster_info *cinfo = mddev->cluster_info;
1439	int ret = 0;
1440
1441	if ((direction == READ) &&
1442		test_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state))
1443		return 1;
1444
1445	spin_lock_irq(&cinfo->suspend_lock);
1446	if (hi > cinfo->suspend_lo && lo < cinfo->suspend_hi)
1447		ret = 1;
1448	spin_unlock_irq(&cinfo->suspend_lock);
1449	return ret;
1450}
1451
1452/* add_new_disk() - initiates a disk add
1453 * However, if this fails before writing md_update_sb(),
1454 * add_new_disk_cancel() must be called to release token lock
1455 */
1456static int add_new_disk(struct mddev *mddev, struct md_rdev *rdev)
1457{
1458	struct md_cluster_info *cinfo = mddev->cluster_info;
1459	struct cluster_msg cmsg;
1460	int ret = 0;
1461	struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1462	char *uuid = sb->device_uuid;
1463
1464	memset(&cmsg, 0, sizeof(cmsg));
1465	cmsg.type = cpu_to_le32(NEWDISK);
1466	memcpy(cmsg.uuid, uuid, 16);
1467	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1468	if (lock_comm(cinfo, 1))
1469		return -EAGAIN;
1470	ret = __sendmsg(cinfo, &cmsg);
1471	if (ret) {
1472		unlock_comm(cinfo);
1473		return ret;
1474	}
1475	cinfo->no_new_dev_lockres->flags |= DLM_LKF_NOQUEUE;
1476	ret = dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_EX);
1477	cinfo->no_new_dev_lockres->flags &= ~DLM_LKF_NOQUEUE;
1478	/* Some node does not "see" the device */
1479	if (ret == -EAGAIN)
1480		ret = -ENOENT;
1481	if (ret)
1482		unlock_comm(cinfo);
1483	else {
1484		dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
1485		/* Since MD_CHANGE_DEVS will be set in add_bound_rdev which
1486		 * will run soon after add_new_disk, the below path will be
1487		 * invoked:
1488		 *   md_wakeup_thread(mddev->thread)
1489		 *	-> conf->thread (raid1d)
1490		 *	-> md_check_recovery -> md_update_sb
1491		 *	-> metadata_update_start/finish
1492		 * MD_CLUSTER_SEND_LOCKED_ALREADY will be cleared eventually.
1493		 *
1494		 * For other failure cases, metadata_update_cancel and
1495		 * add_new_disk_cancel also clear below bit as well.
1496		 * */
1497		set_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1498		wake_up(&cinfo->wait);
1499	}
1500	return ret;
1501}
1502
1503static void add_new_disk_cancel(struct mddev *mddev)
1504{
1505	struct md_cluster_info *cinfo = mddev->cluster_info;
1506	clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1507	unlock_comm(cinfo);
1508}
1509
1510static int new_disk_ack(struct mddev *mddev, bool ack)
1511{
1512	struct md_cluster_info *cinfo = mddev->cluster_info;
1513
1514	if (!test_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state)) {
1515		pr_warn("md-cluster(%s): Spurious cluster confirmation\n", mdname(mddev));
1516		return -EINVAL;
1517	}
1518
1519	if (ack)
1520		dlm_unlock_sync(cinfo->no_new_dev_lockres);
1521	complete(&cinfo->newdisk_completion);
1522	return 0;
1523}
1524
1525static int remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1526{
1527	struct cluster_msg cmsg = {0};
1528	struct md_cluster_info *cinfo = mddev->cluster_info;
1529	cmsg.type = cpu_to_le32(REMOVE);
1530	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1531	return sendmsg(cinfo, &cmsg, 1);
1532}
1533
1534static int lock_all_bitmaps(struct mddev *mddev)
1535{
1536	int slot, my_slot, ret, held = 1, i = 0;
1537	char str[64];
1538	struct md_cluster_info *cinfo = mddev->cluster_info;
1539
1540	cinfo->other_bitmap_lockres =
1541		kcalloc(mddev->bitmap_info.nodes - 1,
1542			sizeof(struct dlm_lock_resource *), GFP_KERNEL);
1543	if (!cinfo->other_bitmap_lockres) {
1544		pr_err("md: can't alloc mem for other bitmap locks\n");
1545		return 0;
1546	}
1547
1548	my_slot = slot_number(mddev);
1549	for (slot = 0; slot < mddev->bitmap_info.nodes; slot++) {
1550		if (slot == my_slot)
1551			continue;
1552
1553		memset(str, '\0', 64);
1554		snprintf(str, 64, "bitmap%04d", slot);
1555		cinfo->other_bitmap_lockres[i] = lockres_init(mddev, str, NULL, 1);
1556		if (!cinfo->other_bitmap_lockres[i])
1557			return -ENOMEM;
1558
1559		cinfo->other_bitmap_lockres[i]->flags |= DLM_LKF_NOQUEUE;
1560		ret = dlm_lock_sync(cinfo->other_bitmap_lockres[i], DLM_LOCK_PW);
1561		if (ret)
1562			held = -1;
1563		i++;
1564	}
1565
1566	return held;
1567}
1568
1569static void unlock_all_bitmaps(struct mddev *mddev)
1570{
1571	struct md_cluster_info *cinfo = mddev->cluster_info;
1572	int i;
1573
1574	/* release other node's bitmap lock if they are existed */
1575	if (cinfo->other_bitmap_lockres) {
1576		for (i = 0; i < mddev->bitmap_info.nodes - 1; i++) {
1577			if (cinfo->other_bitmap_lockres[i]) {
1578				lockres_free(cinfo->other_bitmap_lockres[i]);
1579			}
1580		}
1581		kfree(cinfo->other_bitmap_lockres);
1582		cinfo->other_bitmap_lockres = NULL;
1583	}
1584}
1585
1586static int gather_bitmaps(struct md_rdev *rdev)
1587{
1588	int sn, err;
1589	sector_t lo, hi;
1590	struct cluster_msg cmsg = {0};
1591	struct mddev *mddev = rdev->mddev;
1592	struct md_cluster_info *cinfo = mddev->cluster_info;
1593
1594	cmsg.type = cpu_to_le32(RE_ADD);
1595	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1596	err = sendmsg(cinfo, &cmsg, 1);
1597	if (err)
1598		goto out;
1599
1600	for (sn = 0; sn < mddev->bitmap_info.nodes; sn++) {
1601		if (sn == (cinfo->slot_number - 1))
1602			continue;
1603		err = mddev->bitmap_ops->copy_from_slot(mddev, sn, &lo, &hi, false);
1604		if (err) {
1605			pr_warn("md-cluster: Could not gather bitmaps from slot %d", sn);
1606			goto out;
1607		}
1608		if ((hi > 0) && (lo < mddev->recovery_cp))
1609			mddev->recovery_cp = lo;
1610	}
1611out:
1612	return err;
1613}
1614
1615static const struct md_cluster_operations cluster_ops = {
1616	.join   = join,
1617	.leave  = leave,
1618	.slot_number = slot_number,
1619	.resync_start = resync_start,
1620	.resync_finish = resync_finish,
1621	.resync_info_update = resync_info_update,
1622	.resync_start_notify = resync_start_notify,
1623	.resync_status_get = resync_status_get,
1624	.resync_info_get = resync_info_get,
1625	.metadata_update_start = metadata_update_start,
1626	.metadata_update_finish = metadata_update_finish,
1627	.metadata_update_cancel = metadata_update_cancel,
1628	.area_resyncing = area_resyncing,
1629	.add_new_disk = add_new_disk,
1630	.add_new_disk_cancel = add_new_disk_cancel,
1631	.new_disk_ack = new_disk_ack,
1632	.remove_disk = remove_disk,
1633	.load_bitmaps = load_bitmaps,
1634	.gather_bitmaps = gather_bitmaps,
1635	.resize_bitmaps = resize_bitmaps,
1636	.lock_all_bitmaps = lock_all_bitmaps,
1637	.unlock_all_bitmaps = unlock_all_bitmaps,
1638	.update_size = update_size,
1639};
1640
1641static int __init cluster_init(void)
1642{
1643	pr_warn("md-cluster: support raid1 and raid10 (limited support)\n");
1644	pr_info("Registering Cluster MD functions\n");
1645	register_md_cluster_operations(&cluster_ops, THIS_MODULE);
1646	return 0;
1647}
1648
1649static void cluster_exit(void)
1650{
1651	unregister_md_cluster_operations();
1652}
1653
1654module_init(cluster_init);
1655module_exit(cluster_exit);
1656MODULE_AUTHOR("SUSE");
1657MODULE_LICENSE("GPL");
1658MODULE_DESCRIPTION("Clustering support for MD");