Linux Audio

Check our new training course

In-person Linux kernel drivers training

Jun 16-20, 2025
Register
Loading...
v6.8
   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
  19struct dlm_lock_resource {
  20	dlm_lockspace_t *ls;
  21	struct dlm_lksb lksb;
  22	char *name; /* lock name. */
  23	uint32_t flags; /* flags to pass to dlm_lock() */
  24	wait_queue_head_t sync_locking; /* wait queue for synchronized locking */
  25	bool sync_locking_done;
  26	void (*bast)(void *arg, int mode); /* blocking AST function pointer*/
  27	struct mddev *mddev; /* pointing back to mddev. */
  28	int mode;
  29};
  30
 
 
 
 
 
 
 
  31struct resync_info {
  32	__le64 lo;
  33	__le64 hi;
  34};
  35
  36/* md_cluster_info flags */
  37#define		MD_CLUSTER_WAITING_FOR_NEWDISK		1
  38#define		MD_CLUSTER_SUSPEND_READ_BALANCING	2
  39#define		MD_CLUSTER_BEGIN_JOIN_CLUSTER		3
  40
  41/* Lock the send communication. This is done through
  42 * bit manipulation as opposed to a mutex in order to
  43 * accommodate lock and hold. See next comment.
  44 */
  45#define		MD_CLUSTER_SEND_LOCK			4
  46/* If cluster operations (such as adding a disk) must lock the
  47 * communication channel, so as to perform extra operations
  48 * (update metadata) and no other operation is allowed on the
  49 * MD. Token needs to be locked and held until the operation
  50 * completes witha md_update_sb(), which would eventually release
  51 * the lock.
  52 */
  53#define		MD_CLUSTER_SEND_LOCKED_ALREADY		5
  54/* We should receive message after node joined cluster and
  55 * set up all the related infos such as bitmap and personality */
  56#define		MD_CLUSTER_ALREADY_IN_CLUSTER		6
  57#define		MD_CLUSTER_PENDING_RECV_EVENT		7
  58#define 	MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD		8
  59
  60struct md_cluster_info {
  61	struct mddev *mddev; /* the md device which md_cluster_info belongs to */
  62	/* dlm lock space and resources for clustered raid. */
  63	dlm_lockspace_t *lockspace;
  64	int slot_number;
  65	struct completion completion;
  66	struct mutex recv_mutex;
  67	struct dlm_lock_resource *bitmap_lockres;
  68	struct dlm_lock_resource **other_bitmap_lockres;
  69	struct dlm_lock_resource *resync_lockres;
  70	struct list_head suspend_list;
  71
  72	spinlock_t suspend_lock;
  73	/* record the region which write should be suspended */
  74	sector_t suspend_lo;
  75	sector_t suspend_hi;
  76	int suspend_from; /* the slot which broadcast suspend_lo/hi */
  77
  78	struct md_thread __rcu *recovery_thread;
  79	unsigned long recovery_map;
  80	/* communication loc resources */
  81	struct dlm_lock_resource *ack_lockres;
  82	struct dlm_lock_resource *message_lockres;
  83	struct dlm_lock_resource *token_lockres;
  84	struct dlm_lock_resource *no_new_dev_lockres;
  85	struct md_thread __rcu *recv_thread;
  86	struct completion newdisk_completion;
  87	wait_queue_head_t wait;
  88	unsigned long state;
  89	/* record the region in RESYNCING message */
  90	sector_t sync_low;
  91	sector_t sync_hi;
  92};
  93
  94enum msg_type {
  95	METADATA_UPDATED = 0,
  96	RESYNCING,
  97	NEWDISK,
  98	REMOVE,
  99	RE_ADD,
 100	BITMAP_NEEDS_SYNC,
 101	CHANGE_CAPACITY,
 102	BITMAP_RESIZE,
 103};
 104
 105struct cluster_msg {
 106	__le32 type;
 107	__le32 slot;
 108	/* TODO: Unionize this for smaller footprint */
 109	__le64 low;
 110	__le64 high;
 111	char uuid[16];
 112	__le32 raid_slot;
 113};
 114
 115static void sync_ast(void *arg)
 116{
 117	struct dlm_lock_resource *res;
 118
 119	res = arg;
 120	res->sync_locking_done = true;
 121	wake_up(&res->sync_locking);
 122}
 123
 124static int dlm_lock_sync(struct dlm_lock_resource *res, int mode)
 125{
 126	int ret = 0;
 127
 128	ret = dlm_lock(res->ls, mode, &res->lksb,
 129			res->flags, res->name, strlen(res->name),
 130			0, sync_ast, res, res->bast);
 131	if (ret)
 132		return ret;
 133	wait_event(res->sync_locking, res->sync_locking_done);
 134	res->sync_locking_done = false;
 135	if (res->lksb.sb_status == 0)
 136		res->mode = mode;
 137	return res->lksb.sb_status;
 138}
 139
 140static int dlm_unlock_sync(struct dlm_lock_resource *res)
 141{
 142	return dlm_lock_sync(res, DLM_LOCK_NL);
 143}
 144
 145/*
 146 * An variation of dlm_lock_sync, which make lock request could
 147 * be interrupted
 148 */
 149static int dlm_lock_sync_interruptible(struct dlm_lock_resource *res, int mode,
 150				       struct mddev *mddev)
 151{
 152	int ret = 0;
 153
 154	ret = dlm_lock(res->ls, mode, &res->lksb,
 155			res->flags, res->name, strlen(res->name),
 156			0, sync_ast, res, res->bast);
 157	if (ret)
 158		return ret;
 159
 160	wait_event(res->sync_locking, res->sync_locking_done
 161				      || kthread_should_stop()
 162				      || test_bit(MD_CLOSING, &mddev->flags));
 163	if (!res->sync_locking_done) {
 164		/*
 165		 * the convert queue contains the lock request when request is
 166		 * interrupted, and sync_ast could still be run, so need to
 167		 * cancel the request and reset completion
 168		 */
 169		ret = dlm_unlock(res->ls, res->lksb.sb_lkid, DLM_LKF_CANCEL,
 170			&res->lksb, res);
 171		res->sync_locking_done = false;
 172		if (unlikely(ret != 0))
 173			pr_info("failed to cancel previous lock request "
 174				 "%s return %d\n", res->name, ret);
 175		return -EPERM;
 176	} else
 177		res->sync_locking_done = false;
 178	if (res->lksb.sb_status == 0)
 179		res->mode = mode;
 180	return res->lksb.sb_status;
 181}
 182
 183static struct dlm_lock_resource *lockres_init(struct mddev *mddev,
 184		char *name, void (*bastfn)(void *arg, int mode), int with_lvb)
 185{
 186	struct dlm_lock_resource *res = NULL;
 187	int ret, namelen;
 188	struct md_cluster_info *cinfo = mddev->cluster_info;
 189
 190	res = kzalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL);
 191	if (!res)
 192		return NULL;
 193	init_waitqueue_head(&res->sync_locking);
 194	res->sync_locking_done = false;
 195	res->ls = cinfo->lockspace;
 196	res->mddev = mddev;
 197	res->mode = DLM_LOCK_IV;
 198	namelen = strlen(name);
 199	res->name = kzalloc(namelen + 1, GFP_KERNEL);
 200	if (!res->name) {
 201		pr_err("md-cluster: Unable to allocate resource name for resource %s\n", name);
 202		goto out_err;
 203	}
 204	strscpy(res->name, name, namelen + 1);
 205	if (with_lvb) {
 206		res->lksb.sb_lvbptr = kzalloc(LVB_SIZE, GFP_KERNEL);
 207		if (!res->lksb.sb_lvbptr) {
 208			pr_err("md-cluster: Unable to allocate LVB for resource %s\n", name);
 209			goto out_err;
 210		}
 211		res->flags = DLM_LKF_VALBLK;
 212	}
 213
 214	if (bastfn)
 215		res->bast = bastfn;
 216
 217	res->flags |= DLM_LKF_EXPEDITE;
 218
 219	ret = dlm_lock_sync(res, DLM_LOCK_NL);
 220	if (ret) {
 221		pr_err("md-cluster: Unable to lock NL on new lock resource %s\n", name);
 222		goto out_err;
 223	}
 224	res->flags &= ~DLM_LKF_EXPEDITE;
 225	res->flags |= DLM_LKF_CONVERT;
 226
 227	return res;
 228out_err:
 229	kfree(res->lksb.sb_lvbptr);
 230	kfree(res->name);
 231	kfree(res);
 232	return NULL;
 233}
 234
 235static void lockres_free(struct dlm_lock_resource *res)
 236{
 237	int ret = 0;
 238
 239	if (!res)
 240		return;
 241
 242	/*
 243	 * use FORCEUNLOCK flag, so we can unlock even the lock is on the
 244	 * waiting or convert queue
 245	 */
 246	ret = dlm_unlock(res->ls, res->lksb.sb_lkid, DLM_LKF_FORCEUNLOCK,
 247		&res->lksb, res);
 248	if (unlikely(ret != 0))
 249		pr_err("failed to unlock %s return %d\n", res->name, ret);
 250	else
 251		wait_event(res->sync_locking, res->sync_locking_done);
 
 
 
 
 252
 253	kfree(res->name);
 254	kfree(res->lksb.sb_lvbptr);
 255	kfree(res);
 256}
 257
 258static void add_resync_info(struct dlm_lock_resource *lockres,
 259			    sector_t lo, sector_t hi)
 260{
 261	struct resync_info *ri;
 262
 263	ri = (struct resync_info *)lockres->lksb.sb_lvbptr;
 264	ri->lo = cpu_to_le64(lo);
 265	ri->hi = cpu_to_le64(hi);
 266}
 267
 268static int read_resync_info(struct mddev *mddev,
 269			    struct dlm_lock_resource *lockres)
 270{
 271	struct resync_info ri;
 272	struct md_cluster_info *cinfo = mddev->cluster_info;
 273	int ret = 0;
 274
 275	dlm_lock_sync(lockres, DLM_LOCK_CR);
 276	memcpy(&ri, lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
 277	if (le64_to_cpu(ri.hi) > 0) {
 278		cinfo->suspend_hi = le64_to_cpu(ri.hi);
 279		cinfo->suspend_lo = le64_to_cpu(ri.lo);
 280		ret = 1;
 
 
 
 281	}
 282	dlm_unlock_sync(lockres);
 283	return ret;
 
 284}
 285
 286static void recover_bitmaps(struct md_thread *thread)
 287{
 288	struct mddev *mddev = thread->mddev;
 289	struct md_cluster_info *cinfo = mddev->cluster_info;
 290	struct dlm_lock_resource *bm_lockres;
 291	char str[64];
 292	int slot, ret;
 
 293	sector_t lo, hi;
 294
 295	while (cinfo->recovery_map) {
 296		slot = fls64((u64)cinfo->recovery_map) - 1;
 297
 
 
 
 
 
 
 
 
 
 298		snprintf(str, 64, "bitmap%04d", slot);
 299		bm_lockres = lockres_init(mddev, str, NULL, 1);
 300		if (!bm_lockres) {
 301			pr_err("md-cluster: Cannot initialize bitmaps\n");
 302			goto clear_bit;
 303		}
 304
 305		ret = dlm_lock_sync_interruptible(bm_lockres, DLM_LOCK_PW, mddev);
 306		if (ret) {
 307			pr_err("md-cluster: Could not DLM lock %s: %d\n",
 308					str, ret);
 309			goto clear_bit;
 310		}
 311		ret = md_bitmap_copy_from_slot(mddev, slot, &lo, &hi, true);
 312		if (ret) {
 313			pr_err("md-cluster: Could not copy data from bitmap %d\n", slot);
 314			goto clear_bit;
 315		}
 316
 317		/* Clear suspend_area associated with the bitmap */
 318		spin_lock_irq(&cinfo->suspend_lock);
 319		cinfo->suspend_hi = 0;
 320		cinfo->suspend_lo = 0;
 321		cinfo->suspend_from = -1;
 322		spin_unlock_irq(&cinfo->suspend_lock);
 323
 324		/* Kick off a reshape if needed */
 325		if (test_bit(MD_RESYNCING_REMOTE, &mddev->recovery) &&
 326		    test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
 327		    mddev->reshape_position != MaxSector)
 328			md_wakeup_thread(mddev->sync_thread);
 329
 330		if (hi > 0) {
 
 
 331			if (lo < mddev->recovery_cp)
 332				mddev->recovery_cp = lo;
 333			/* wake up thread to continue resync in case resync
 334			 * is not finished */
 335			if (mddev->recovery_cp != MaxSector) {
 336				/*
 337				 * clear the REMOTE flag since we will launch
 338				 * resync thread in current node.
 339				 */
 340				clear_bit(MD_RESYNCING_REMOTE,
 341					  &mddev->recovery);
 342				set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 343				md_wakeup_thread(mddev->thread);
 344			}
 345		}
 
 
 346clear_bit:
 347		lockres_free(bm_lockres);
 348		clear_bit(slot, &cinfo->recovery_map);
 349	}
 350}
 351
 352static void recover_prep(void *arg)
 353{
 354	struct mddev *mddev = arg;
 355	struct md_cluster_info *cinfo = mddev->cluster_info;
 356	set_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state);
 357}
 358
 359static void __recover_slot(struct mddev *mddev, int slot)
 360{
 361	struct md_cluster_info *cinfo = mddev->cluster_info;
 362
 363	set_bit(slot, &cinfo->recovery_map);
 364	if (!cinfo->recovery_thread) {
 365		rcu_assign_pointer(cinfo->recovery_thread,
 366			md_register_thread(recover_bitmaps, mddev, "recover"));
 367		if (!cinfo->recovery_thread) {
 368			pr_warn("md-cluster: Could not create recovery thread\n");
 369			return;
 370		}
 371	}
 372	md_wakeup_thread(cinfo->recovery_thread);
 373}
 374
 375static void recover_slot(void *arg, struct dlm_slot *slot)
 376{
 377	struct mddev *mddev = arg;
 378	struct md_cluster_info *cinfo = mddev->cluster_info;
 379
 380	pr_info("md-cluster: %s Node %d/%d down. My slot: %d. Initiating recovery.\n",
 381			mddev->bitmap_info.cluster_name,
 382			slot->nodeid, slot->slot,
 383			cinfo->slot_number);
 384	/* deduct one since dlm slot starts from one while the num of
 385	 * cluster-md begins with 0 */
 386	__recover_slot(mddev, slot->slot - 1);
 387}
 388
 389static void recover_done(void *arg, struct dlm_slot *slots,
 390		int num_slots, int our_slot,
 391		uint32_t generation)
 392{
 393	struct mddev *mddev = arg;
 394	struct md_cluster_info *cinfo = mddev->cluster_info;
 395
 396	cinfo->slot_number = our_slot;
 397	/* completion is only need to be complete when node join cluster,
 398	 * it doesn't need to run during another node's failure */
 399	if (test_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state)) {
 400		complete(&cinfo->completion);
 401		clear_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state);
 402	}
 403	clear_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state);
 404}
 405
 406/* the ops is called when node join the cluster, and do lock recovery
 407 * if node failure occurs */
 408static const struct dlm_lockspace_ops md_ls_ops = {
 409	.recover_prep = recover_prep,
 410	.recover_slot = recover_slot,
 411	.recover_done = recover_done,
 412};
 413
 414/*
 415 * The BAST function for the ack lock resource
 416 * This function wakes up the receive thread in
 417 * order to receive and process the message.
 418 */
 419static void ack_bast(void *arg, int mode)
 420{
 421	struct dlm_lock_resource *res = arg;
 422	struct md_cluster_info *cinfo = res->mddev->cluster_info;
 423
 424	if (mode == DLM_LOCK_EX) {
 425		if (test_bit(MD_CLUSTER_ALREADY_IN_CLUSTER, &cinfo->state))
 426			md_wakeup_thread(cinfo->recv_thread);
 427		else
 428			set_bit(MD_CLUSTER_PENDING_RECV_EVENT, &cinfo->state);
 429	}
 
 
 
 
 
 
 
 
 430}
 431
 432static void remove_suspend_info(struct mddev *mddev, int slot)
 433{
 434	struct md_cluster_info *cinfo = mddev->cluster_info;
 435	mddev->pers->quiesce(mddev, 1);
 436	spin_lock_irq(&cinfo->suspend_lock);
 437	cinfo->suspend_hi = 0;
 438	cinfo->suspend_lo = 0;
 439	spin_unlock_irq(&cinfo->suspend_lock);
 440	mddev->pers->quiesce(mddev, 0);
 441}
 442
 
 443static void process_suspend_info(struct mddev *mddev,
 444		int slot, sector_t lo, sector_t hi)
 445{
 446	struct md_cluster_info *cinfo = mddev->cluster_info;
 447	struct mdp_superblock_1 *sb = NULL;
 448	struct md_rdev *rdev;
 449
 450	if (!hi) {
 451		/*
 452		 * clear the REMOTE flag since resync or recovery is finished
 453		 * in remote node.
 454		 */
 455		clear_bit(MD_RESYNCING_REMOTE, &mddev->recovery);
 456		remove_suspend_info(mddev, slot);
 457		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 458		md_wakeup_thread(mddev->thread);
 459		return;
 460	}
 461
 462	rdev_for_each(rdev, mddev)
 463		if (rdev->raid_disk > -1 && !test_bit(Faulty, &rdev->flags)) {
 464			sb = page_address(rdev->sb_page);
 465			break;
 466		}
 467
 468	/*
 469	 * The bitmaps are not same for different nodes
 470	 * if RESYNCING is happening in one node, then
 471	 * the node which received the RESYNCING message
 472	 * probably will perform resync with the region
 473	 * [lo, hi] again, so we could reduce resync time
 474	 * a lot if we can ensure that the bitmaps among
 475	 * different nodes are match up well.
 476	 *
 477	 * sync_low/hi is used to record the region which
 478	 * arrived in the previous RESYNCING message,
 479	 *
 480	 * Call md_bitmap_sync_with_cluster to clear NEEDED_MASK
 481	 * and set RESYNC_MASK since  resync thread is running
 482	 * in another node, so we don't need to do the resync
 483	 * again with the same section.
 484	 *
 485	 * Skip md_bitmap_sync_with_cluster in case reshape
 486	 * happening, because reshaping region is small and
 487	 * we don't want to trigger lots of WARN.
 488	 */
 489	if (sb && !(le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE))
 490		md_bitmap_sync_with_cluster(mddev, cinfo->sync_low,
 491					    cinfo->sync_hi, lo, hi);
 492	cinfo->sync_low = lo;
 493	cinfo->sync_hi = hi;
 494
 495	mddev->pers->quiesce(mddev, 1);
 
 496	spin_lock_irq(&cinfo->suspend_lock);
 497	cinfo->suspend_from = slot;
 498	cinfo->suspend_lo = lo;
 499	cinfo->suspend_hi = hi;
 500	spin_unlock_irq(&cinfo->suspend_lock);
 501	mddev->pers->quiesce(mddev, 0);
 502}
 503
 504static int process_add_new_disk(struct mddev *mddev, struct cluster_msg *cmsg)
 505{
 506	char disk_uuid[64];
 507	struct md_cluster_info *cinfo = mddev->cluster_info;
 508	char event_name[] = "EVENT=ADD_DEVICE";
 509	char raid_slot[16];
 510	char *envp[] = {event_name, disk_uuid, raid_slot, NULL};
 511	int len;
 512	int res = 0;
 513
 514	len = snprintf(disk_uuid, 64, "DEVICE_UUID=");
 515	sprintf(disk_uuid + len, "%pU", cmsg->uuid);
 516	snprintf(raid_slot, 16, "RAID_DISK=%d", le32_to_cpu(cmsg->raid_slot));
 517	pr_info("%s:%d Sending kobject change with %s and %s\n", __func__, __LINE__, disk_uuid, raid_slot);
 518	init_completion(&cinfo->newdisk_completion);
 519	set_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state);
 520	kobject_uevent_env(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE, envp);
 521	if (!wait_for_completion_timeout(&cinfo->newdisk_completion,
 522					NEW_DEV_TIMEOUT)) {
 523		pr_err("md-cluster(%s:%d): timeout on a new disk adding\n",
 524			__func__, __LINE__);
 525		res = -1;
 526	}
 527	clear_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state);
 528	return res;
 529}
 530
 531
 532static void process_metadata_update(struct mddev *mddev, struct cluster_msg *msg)
 533{
 534	int got_lock = 0;
 535	struct md_thread *thread;
 536	struct md_cluster_info *cinfo = mddev->cluster_info;
 537	mddev->good_device_nr = le32_to_cpu(msg->raid_slot);
 538
 539	dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
 540
 541	/* daemaon thread must exist */
 542	thread = rcu_dereference_protected(mddev->thread, true);
 543	wait_event(thread->wqueue,
 544		   (got_lock = mddev_trylock(mddev)) ||
 545		    test_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state));
 546	md_reload_sb(mddev, mddev->good_device_nr);
 547	if (got_lock)
 548		mddev_unlock(mddev);
 549}
 550
 551static void process_remove_disk(struct mddev *mddev, struct cluster_msg *msg)
 552{
 553	struct md_rdev *rdev;
 
 554
 555	rcu_read_lock();
 556	rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));
 557	if (rdev) {
 558		set_bit(ClusterRemove, &rdev->flags);
 559		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 560		md_wakeup_thread(mddev->thread);
 561	}
 562	else
 563		pr_warn("%s: %d Could not find disk(%d) to REMOVE\n",
 564			__func__, __LINE__, le32_to_cpu(msg->raid_slot));
 565	rcu_read_unlock();
 566}
 567
 568static void process_readd_disk(struct mddev *mddev, struct cluster_msg *msg)
 569{
 570	struct md_rdev *rdev;
 
 571
 572	rcu_read_lock();
 573	rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));
 574	if (rdev && test_bit(Faulty, &rdev->flags))
 575		clear_bit(Faulty, &rdev->flags);
 576	else
 577		pr_warn("%s: %d Could not find disk(%d) which is faulty",
 578			__func__, __LINE__, le32_to_cpu(msg->raid_slot));
 579	rcu_read_unlock();
 580}
 581
 582static int process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
 583{
 584	int ret = 0;
 585
 586	if (WARN(mddev->cluster_info->slot_number - 1 == le32_to_cpu(msg->slot),
 587		"node %d received its own msg\n", le32_to_cpu(msg->slot)))
 588		return -1;
 589	switch (le32_to_cpu(msg->type)) {
 590	case METADATA_UPDATED:
 591		process_metadata_update(mddev, msg);
 592		break;
 593	case CHANGE_CAPACITY:
 594		set_capacity_and_notify(mddev->gendisk, mddev->array_sectors);
 595		break;
 596	case RESYNCING:
 597		set_bit(MD_RESYNCING_REMOTE, &mddev->recovery);
 598		process_suspend_info(mddev, le32_to_cpu(msg->slot),
 599				     le64_to_cpu(msg->low),
 600				     le64_to_cpu(msg->high));
 601		break;
 602	case NEWDISK:
 603		if (process_add_new_disk(mddev, msg))
 604			ret = -1;
 605		break;
 606	case REMOVE:
 607		process_remove_disk(mddev, msg);
 608		break;
 609	case RE_ADD:
 610		process_readd_disk(mddev, msg);
 611		break;
 612	case BITMAP_NEEDS_SYNC:
 613		__recover_slot(mddev, le32_to_cpu(msg->slot));
 614		break;
 615	case BITMAP_RESIZE:
 616		if (le64_to_cpu(msg->high) != mddev->pers->size(mddev, 0, 0))
 617			ret = md_bitmap_resize(mddev->bitmap,
 618					    le64_to_cpu(msg->high), 0, 0);
 619		break;
 620	default:
 621		ret = -1;
 622		pr_warn("%s:%d Received unknown message from %d\n",
 623			__func__, __LINE__, msg->slot);
 624	}
 625	return ret;
 626}
 627
 628/*
 629 * thread for receiving message
 630 */
 631static void recv_daemon(struct md_thread *thread)
 632{
 633	struct md_cluster_info *cinfo = thread->mddev->cluster_info;
 634	struct dlm_lock_resource *ack_lockres = cinfo->ack_lockres;
 635	struct dlm_lock_resource *message_lockres = cinfo->message_lockres;
 636	struct cluster_msg msg;
 637	int ret;
 638
 639	mutex_lock(&cinfo->recv_mutex);
 640	/*get CR on Message*/
 641	if (dlm_lock_sync(message_lockres, DLM_LOCK_CR)) {
 642		pr_err("md/raid1:failed to get CR on MESSAGE\n");
 643		mutex_unlock(&cinfo->recv_mutex);
 644		return;
 645	}
 646
 647	/* read lvb and wake up thread to process this message_lockres */
 648	memcpy(&msg, message_lockres->lksb.sb_lvbptr, sizeof(struct cluster_msg));
 649	ret = process_recvd_msg(thread->mddev, &msg);
 650	if (ret)
 651		goto out;
 652
 653	/*release CR on ack_lockres*/
 654	ret = dlm_unlock_sync(ack_lockres);
 655	if (unlikely(ret != 0))
 656		pr_info("unlock ack failed return %d\n", ret);
 657	/*up-convert to PR on message_lockres*/
 658	ret = dlm_lock_sync(message_lockres, DLM_LOCK_PR);
 659	if (unlikely(ret != 0))
 660		pr_info("lock PR on msg failed return %d\n", ret);
 661	/*get CR on ack_lockres again*/
 662	ret = dlm_lock_sync(ack_lockres, DLM_LOCK_CR);
 663	if (unlikely(ret != 0))
 664		pr_info("lock CR on ack failed return %d\n", ret);
 665out:
 666	/*release CR on message_lockres*/
 667	ret = dlm_unlock_sync(message_lockres);
 668	if (unlikely(ret != 0))
 669		pr_info("unlock msg failed return %d\n", ret);
 670	mutex_unlock(&cinfo->recv_mutex);
 671}
 672
 673/* lock_token()
 674 * Takes the lock on the TOKEN lock resource so no other
 675 * node can communicate while the operation is underway.
 676 */
 677static int lock_token(struct md_cluster_info *cinfo)
 678{
 679	int error;
 680
 681	error = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
 682	if (error) {
 683		pr_err("md-cluster(%s:%d): failed to get EX on TOKEN (%d)\n",
 684				__func__, __LINE__, error);
 685	} else {
 686		/* Lock the receive sequence */
 687		mutex_lock(&cinfo->recv_mutex);
 688	}
 689	return error;
 690}
 691
 692/* lock_comm()
 693 * Sets the MD_CLUSTER_SEND_LOCK bit to lock the send channel.
 694 */
 695static int lock_comm(struct md_cluster_info *cinfo, bool mddev_locked)
 696{
 697	int rv, set_bit = 0;
 698	struct mddev *mddev = cinfo->mddev;
 699
 700	/*
 701	 * If resync thread run after raid1d thread, then process_metadata_update
 702	 * could not continue if raid1d held reconfig_mutex (and raid1d is blocked
 703	 * since another node already got EX on Token and waiting the EX of Ack),
 704	 * so let resync wake up thread in case flag is set.
 705	 */
 706	if (mddev_locked && !test_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
 707				      &cinfo->state)) {
 708		rv = test_and_set_bit_lock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
 709					      &cinfo->state);
 710		WARN_ON_ONCE(rv);
 711		md_wakeup_thread(mddev->thread);
 712		set_bit = 1;
 713	}
 714
 715	wait_event(cinfo->wait,
 716		   !test_and_set_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state));
 717	rv = lock_token(cinfo);
 718	if (set_bit)
 719		clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
 720	return rv;
 721}
 722
 723static void unlock_comm(struct md_cluster_info *cinfo)
 724{
 725	WARN_ON(cinfo->token_lockres->mode != DLM_LOCK_EX);
 726	mutex_unlock(&cinfo->recv_mutex);
 727	dlm_unlock_sync(cinfo->token_lockres);
 728	clear_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state);
 729	wake_up(&cinfo->wait);
 730}
 731
 732/* __sendmsg()
 733 * This function performs the actual sending of the message. This function is
 734 * usually called after performing the encompassing operation
 735 * The function:
 736 * 1. Grabs the message lockresource in EX mode
 737 * 2. Copies the message to the message LVB
 738 * 3. Downconverts message lockresource to CW
 739 * 4. Upconverts ack lock resource from CR to EX. This forces the BAST on other nodes
 740 *    and the other nodes read the message. The thread will wait here until all other
 741 *    nodes have released ack lock resource.
 742 * 5. Downconvert ack lockresource to CR
 743 */
 744static int __sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg)
 745{
 746	int error;
 747	int slot = cinfo->slot_number - 1;
 748
 749	cmsg->slot = cpu_to_le32(slot);
 750	/*get EX on Message*/
 751	error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_EX);
 752	if (error) {
 753		pr_err("md-cluster: failed to get EX on MESSAGE (%d)\n", error);
 754		goto failed_message;
 755	}
 756
 757	memcpy(cinfo->message_lockres->lksb.sb_lvbptr, (void *)cmsg,
 758			sizeof(struct cluster_msg));
 759	/*down-convert EX to CW on Message*/
 760	error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_CW);
 761	if (error) {
 762		pr_err("md-cluster: failed to convert EX to CW on MESSAGE(%d)\n",
 763				error);
 764		goto failed_ack;
 765	}
 766
 767	/*up-convert CR to EX on Ack*/
 768	error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_EX);
 769	if (error) {
 770		pr_err("md-cluster: failed to convert CR to EX on ACK(%d)\n",
 771				error);
 772		goto failed_ack;
 773	}
 774
 775	/*down-convert EX to CR on Ack*/
 776	error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR);
 777	if (error) {
 778		pr_err("md-cluster: failed to convert EX to CR on ACK(%d)\n",
 779				error);
 780		goto failed_ack;
 781	}
 782
 783failed_ack:
 784	error = dlm_unlock_sync(cinfo->message_lockres);
 785	if (unlikely(error != 0)) {
 786		pr_err("md-cluster: failed convert to NL on MESSAGE(%d)\n",
 787			error);
 788		/* in case the message can't be released due to some reason */
 789		goto failed_ack;
 790	}
 791failed_message:
 792	return error;
 793}
 794
 795static int sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg,
 796		   bool mddev_locked)
 797{
 798	int ret;
 799
 800	ret = lock_comm(cinfo, mddev_locked);
 801	if (!ret) {
 802		ret = __sendmsg(cinfo, cmsg);
 803		unlock_comm(cinfo);
 804	}
 805	return ret;
 806}
 807
 808static int gather_all_resync_info(struct mddev *mddev, int total_slots)
 809{
 810	struct md_cluster_info *cinfo = mddev->cluster_info;
 811	int i, ret = 0;
 812	struct dlm_lock_resource *bm_lockres;
 
 813	char str[64];
 814	sector_t lo, hi;
 815
 816
 817	for (i = 0; i < total_slots; i++) {
 818		memset(str, '\0', 64);
 819		snprintf(str, 64, "bitmap%04d", i);
 820		bm_lockres = lockres_init(mddev, str, NULL, 1);
 821		if (!bm_lockres)
 822			return -ENOMEM;
 823		if (i == (cinfo->slot_number - 1)) {
 824			lockres_free(bm_lockres);
 825			continue;
 826		}
 827
 828		bm_lockres->flags |= DLM_LKF_NOQUEUE;
 829		ret = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
 830		if (ret == -EAGAIN) {
 831			if (read_resync_info(mddev, bm_lockres)) {
 
 
 832				pr_info("%s:%d Resync[%llu..%llu] in progress on %d\n",
 833						__func__, __LINE__,
 834					(unsigned long long) cinfo->suspend_lo,
 835					(unsigned long long) cinfo->suspend_hi,
 836					i);
 837				cinfo->suspend_from = i;
 
 
 838			}
 839			ret = 0;
 840			lockres_free(bm_lockres);
 841			continue;
 842		}
 843		if (ret) {
 844			lockres_free(bm_lockres);
 845			goto out;
 846		}
 847
 848		/* Read the disk bitmap sb and check if it needs recovery */
 849		ret = md_bitmap_copy_from_slot(mddev, i, &lo, &hi, false);
 850		if (ret) {
 851			pr_warn("md-cluster: Could not gather bitmaps from slot %d", i);
 852			lockres_free(bm_lockres);
 853			continue;
 854		}
 855		if ((hi > 0) && (lo < mddev->recovery_cp)) {
 856			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 857			mddev->recovery_cp = lo;
 858			md_check_recovery(mddev);
 859		}
 860
 
 861		lockres_free(bm_lockres);
 862	}
 863out:
 864	return ret;
 865}
 866
 867static int join(struct mddev *mddev, int nodes)
 868{
 869	struct md_cluster_info *cinfo;
 870	int ret, ops_rv;
 871	char str[64];
 872
 873	cinfo = kzalloc(sizeof(struct md_cluster_info), GFP_KERNEL);
 874	if (!cinfo)
 875		return -ENOMEM;
 876
 877	INIT_LIST_HEAD(&cinfo->suspend_list);
 878	spin_lock_init(&cinfo->suspend_lock);
 879	init_completion(&cinfo->completion);
 880	set_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state);
 881	init_waitqueue_head(&cinfo->wait);
 882	mutex_init(&cinfo->recv_mutex);
 883
 884	mddev->cluster_info = cinfo;
 885	cinfo->mddev = mddev;
 886
 887	memset(str, 0, 64);
 888	sprintf(str, "%pU", mddev->uuid);
 889	ret = dlm_new_lockspace(str, mddev->bitmap_info.cluster_name,
 890				0, LVB_SIZE, &md_ls_ops, mddev,
 891				&ops_rv, &cinfo->lockspace);
 892	if (ret)
 893		goto err;
 894	wait_for_completion(&cinfo->completion);
 895	if (nodes < cinfo->slot_number) {
 896		pr_err("md-cluster: Slot allotted(%d) is greater than available slots(%d).",
 897			cinfo->slot_number, nodes);
 898		ret = -ERANGE;
 899		goto err;
 900	}
 901	/* Initiate the communication resources */
 902	ret = -ENOMEM;
 903	rcu_assign_pointer(cinfo->recv_thread,
 904			md_register_thread(recv_daemon, mddev, "cluster_recv"));
 905	if (!cinfo->recv_thread) {
 906		pr_err("md-cluster: cannot allocate memory for recv_thread!\n");
 907		goto err;
 908	}
 909	cinfo->message_lockres = lockres_init(mddev, "message", NULL, 1);
 910	if (!cinfo->message_lockres)
 911		goto err;
 912	cinfo->token_lockres = lockres_init(mddev, "token", NULL, 0);
 913	if (!cinfo->token_lockres)
 914		goto err;
 
 
 
 915	cinfo->no_new_dev_lockres = lockres_init(mddev, "no-new-dev", NULL, 0);
 916	if (!cinfo->no_new_dev_lockres)
 917		goto err;
 918
 919	ret = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
 920	if (ret) {
 921		ret = -EAGAIN;
 922		pr_err("md-cluster: can't join cluster to avoid lock issue\n");
 923		goto err;
 924	}
 925	cinfo->ack_lockres = lockres_init(mddev, "ack", ack_bast, 0);
 926	if (!cinfo->ack_lockres) {
 927		ret = -ENOMEM;
 928		goto err;
 929	}
 930	/* get sync CR lock on ACK. */
 931	if (dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR))
 932		pr_err("md-cluster: failed to get a sync CR lock on ACK!(%d)\n",
 933				ret);
 934	dlm_unlock_sync(cinfo->token_lockres);
 935	/* get sync CR lock on no-new-dev. */
 936	if (dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR))
 937		pr_err("md-cluster: failed to get a sync CR lock on no-new-dev!(%d)\n", ret);
 938
 939
 940	pr_info("md-cluster: Joined cluster %s slot %d\n", str, cinfo->slot_number);
 941	snprintf(str, 64, "bitmap%04d", cinfo->slot_number - 1);
 942	cinfo->bitmap_lockres = lockres_init(mddev, str, NULL, 1);
 943	if (!cinfo->bitmap_lockres) {
 944		ret = -ENOMEM;
 945		goto err;
 946	}
 947	if (dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW)) {
 948		pr_err("Failed to get bitmap lock\n");
 949		ret = -EINVAL;
 950		goto err;
 951	}
 952
 953	cinfo->resync_lockres = lockres_init(mddev, "resync", NULL, 0);
 954	if (!cinfo->resync_lockres) {
 955		ret = -ENOMEM;
 
 
 
 956		goto err;
 957	}
 958
 959	return 0;
 960err:
 961	set_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
 962	md_unregister_thread(mddev, &cinfo->recovery_thread);
 963	md_unregister_thread(mddev, &cinfo->recv_thread);
 964	lockres_free(cinfo->message_lockres);
 965	lockres_free(cinfo->token_lockres);
 966	lockres_free(cinfo->ack_lockres);
 967	lockres_free(cinfo->no_new_dev_lockres);
 968	lockres_free(cinfo->resync_lockres);
 969	lockres_free(cinfo->bitmap_lockres);
 970	if (cinfo->lockspace)
 971		dlm_release_lockspace(cinfo->lockspace, 2);
 972	mddev->cluster_info = NULL;
 973	kfree(cinfo);
 974	return ret;
 975}
 976
 977static void load_bitmaps(struct mddev *mddev, int total_slots)
 978{
 979	struct md_cluster_info *cinfo = mddev->cluster_info;
 980
 981	/* load all the node's bitmap info for resync */
 982	if (gather_all_resync_info(mddev, total_slots))
 983		pr_err("md-cluster: failed to gather all resyn infos\n");
 984	set_bit(MD_CLUSTER_ALREADY_IN_CLUSTER, &cinfo->state);
 985	/* wake up recv thread in case something need to be handled */
 986	if (test_and_clear_bit(MD_CLUSTER_PENDING_RECV_EVENT, &cinfo->state))
 987		md_wakeup_thread(cinfo->recv_thread);
 988}
 989
 990static void resync_bitmap(struct mddev *mddev)
 991{
 992	struct md_cluster_info *cinfo = mddev->cluster_info;
 993	struct cluster_msg cmsg = {0};
 994	int err;
 995
 996	cmsg.type = cpu_to_le32(BITMAP_NEEDS_SYNC);
 997	err = sendmsg(cinfo, &cmsg, 1);
 998	if (err)
 999		pr_err("%s:%d: failed to send BITMAP_NEEDS_SYNC message (%d)\n",
1000			__func__, __LINE__, err);
1001}
1002
1003static void unlock_all_bitmaps(struct mddev *mddev);
1004static int leave(struct mddev *mddev)
1005{
1006	struct md_cluster_info *cinfo = mddev->cluster_info;
1007
1008	if (!cinfo)
1009		return 0;
1010
1011	/*
1012	 * BITMAP_NEEDS_SYNC message should be sent when node
1013	 * is leaving the cluster with dirty bitmap, also we
1014	 * can only deliver it when dlm connection is available.
1015	 *
1016	 * Also, we should send BITMAP_NEEDS_SYNC message in
1017	 * case reshaping is interrupted.
1018	 */
1019	if ((cinfo->slot_number > 0 && mddev->recovery_cp != MaxSector) ||
1020	    (mddev->reshape_position != MaxSector &&
1021	     test_bit(MD_CLOSING, &mddev->flags)))
1022		resync_bitmap(mddev);
1023
1024	set_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
1025	md_unregister_thread(mddev, &cinfo->recovery_thread);
1026	md_unregister_thread(mddev, &cinfo->recv_thread);
1027	lockres_free(cinfo->message_lockres);
1028	lockres_free(cinfo->token_lockres);
1029	lockres_free(cinfo->ack_lockres);
1030	lockres_free(cinfo->no_new_dev_lockres);
1031	lockres_free(cinfo->resync_lockres);
1032	lockres_free(cinfo->bitmap_lockres);
1033	unlock_all_bitmaps(mddev);
1034	dlm_release_lockspace(cinfo->lockspace, 2);
1035	kfree(cinfo);
1036	return 0;
1037}
1038
1039/* slot_number(): Returns the MD slot number to use
1040 * DLM starts the slot numbers from 1, wheras cluster-md
1041 * wants the number to be from zero, so we deduct one
1042 */
1043static int slot_number(struct mddev *mddev)
1044{
1045	struct md_cluster_info *cinfo = mddev->cluster_info;
1046
1047	return cinfo->slot_number - 1;
1048}
1049
1050/*
1051 * Check if the communication is already locked, else lock the communication
1052 * channel.
1053 * If it is already locked, token is in EX mode, and hence lock_token()
1054 * should not be called.
1055 */
1056static int metadata_update_start(struct mddev *mddev)
1057{
1058	struct md_cluster_info *cinfo = mddev->cluster_info;
1059	int ret;
1060
1061	/*
1062	 * metadata_update_start is always called with the protection of
1063	 * reconfig_mutex, so set WAITING_FOR_TOKEN here.
1064	 */
1065	ret = test_and_set_bit_lock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
1066				    &cinfo->state);
1067	WARN_ON_ONCE(ret);
1068	md_wakeup_thread(mddev->thread);
1069
1070	wait_event(cinfo->wait,
1071		   !test_and_set_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state) ||
1072		   test_and_clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state));
1073
1074	/* If token is already locked, return 0 */
1075	if (cinfo->token_lockres->mode == DLM_LOCK_EX) {
1076		clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
1077		return 0;
1078	}
1079
1080	ret = lock_token(cinfo);
1081	clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
1082	return ret;
1083}
1084
1085static int metadata_update_finish(struct mddev *mddev)
1086{
1087	struct md_cluster_info *cinfo = mddev->cluster_info;
1088	struct cluster_msg cmsg;
1089	struct md_rdev *rdev;
1090	int ret = 0;
1091	int raid_slot = -1;
1092
1093	memset(&cmsg, 0, sizeof(cmsg));
1094	cmsg.type = cpu_to_le32(METADATA_UPDATED);
1095	/* Pick up a good active device number to send.
1096	 */
1097	rdev_for_each(rdev, mddev)
1098		if (rdev->raid_disk > -1 && !test_bit(Faulty, &rdev->flags)) {
1099			raid_slot = rdev->desc_nr;
1100			break;
1101		}
1102	if (raid_slot >= 0) {
1103		cmsg.raid_slot = cpu_to_le32(raid_slot);
1104		ret = __sendmsg(cinfo, &cmsg);
1105	} else
1106		pr_warn("md-cluster: No good device id found to send\n");
1107	clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1108	unlock_comm(cinfo);
1109	return ret;
1110}
1111
1112static void metadata_update_cancel(struct mddev *mddev)
1113{
1114	struct md_cluster_info *cinfo = mddev->cluster_info;
1115	clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1116	unlock_comm(cinfo);
1117}
1118
1119static int update_bitmap_size(struct mddev *mddev, sector_t size)
1120{
1121	struct md_cluster_info *cinfo = mddev->cluster_info;
1122	struct cluster_msg cmsg = {0};
1123	int ret;
1124
1125	cmsg.type = cpu_to_le32(BITMAP_RESIZE);
1126	cmsg.high = cpu_to_le64(size);
1127	ret = sendmsg(cinfo, &cmsg, 0);
1128	if (ret)
1129		pr_err("%s:%d: failed to send BITMAP_RESIZE message (%d)\n",
1130			__func__, __LINE__, ret);
1131	return ret;
1132}
1133
1134static int resize_bitmaps(struct mddev *mddev, sector_t newsize, sector_t oldsize)
1135{
1136	struct bitmap_counts *counts;
1137	char str[64];
1138	struct dlm_lock_resource *bm_lockres;
1139	struct bitmap *bitmap = mddev->bitmap;
1140	unsigned long my_pages = bitmap->counts.pages;
1141	int i, rv;
1142
1143	/*
1144	 * We need to ensure all the nodes can grow to a larger
1145	 * bitmap size before make the reshaping.
1146	 */
1147	rv = update_bitmap_size(mddev, newsize);
1148	if (rv)
1149		return rv;
1150
1151	for (i = 0; i < mddev->bitmap_info.nodes; i++) {
1152		if (i == md_cluster_ops->slot_number(mddev))
1153			continue;
1154
1155		bitmap = get_bitmap_from_slot(mddev, i);
1156		if (IS_ERR(bitmap)) {
1157			pr_err("can't get bitmap from slot %d\n", i);
1158			bitmap = NULL;
1159			goto out;
1160		}
1161		counts = &bitmap->counts;
1162
1163		/*
1164		 * If we can hold the bitmap lock of one node then
1165		 * the slot is not occupied, update the pages.
1166		 */
1167		snprintf(str, 64, "bitmap%04d", i);
1168		bm_lockres = lockres_init(mddev, str, NULL, 1);
1169		if (!bm_lockres) {
1170			pr_err("Cannot initialize %s lock\n", str);
1171			goto out;
1172		}
1173		bm_lockres->flags |= DLM_LKF_NOQUEUE;
1174		rv = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
1175		if (!rv)
1176			counts->pages = my_pages;
1177		lockres_free(bm_lockres);
1178
1179		if (my_pages != counts->pages)
1180			/*
1181			 * Let's revert the bitmap size if one node
1182			 * can't resize bitmap
1183			 */
1184			goto out;
1185		md_bitmap_free(bitmap);
1186	}
1187
1188	return 0;
1189out:
1190	md_bitmap_free(bitmap);
1191	update_bitmap_size(mddev, oldsize);
1192	return -1;
1193}
1194
1195/*
1196 * return 0 if all the bitmaps have the same sync_size
1197 */
1198static int cluster_check_sync_size(struct mddev *mddev)
1199{
1200	int i, rv;
1201	bitmap_super_t *sb;
1202	unsigned long my_sync_size, sync_size = 0;
1203	int node_num = mddev->bitmap_info.nodes;
1204	int current_slot = md_cluster_ops->slot_number(mddev);
1205	struct bitmap *bitmap = mddev->bitmap;
1206	char str[64];
1207	struct dlm_lock_resource *bm_lockres;
1208
1209	sb = kmap_atomic(bitmap->storage.sb_page);
1210	my_sync_size = sb->sync_size;
1211	kunmap_atomic(sb);
1212
1213	for (i = 0; i < node_num; i++) {
1214		if (i == current_slot)
1215			continue;
1216
1217		bitmap = get_bitmap_from_slot(mddev, i);
1218		if (IS_ERR(bitmap)) {
1219			pr_err("can't get bitmap from slot %d\n", i);
1220			return -1;
1221		}
1222
1223		/*
1224		 * If we can hold the bitmap lock of one node then
1225		 * the slot is not occupied, update the sb.
1226		 */
1227		snprintf(str, 64, "bitmap%04d", i);
1228		bm_lockres = lockres_init(mddev, str, NULL, 1);
1229		if (!bm_lockres) {
1230			pr_err("md-cluster: Cannot initialize %s\n", str);
1231			md_bitmap_free(bitmap);
1232			return -1;
1233		}
1234		bm_lockres->flags |= DLM_LKF_NOQUEUE;
1235		rv = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
1236		if (!rv)
1237			md_bitmap_update_sb(bitmap);
1238		lockres_free(bm_lockres);
1239
1240		sb = kmap_atomic(bitmap->storage.sb_page);
1241		if (sync_size == 0)
1242			sync_size = sb->sync_size;
1243		else if (sync_size != sb->sync_size) {
1244			kunmap_atomic(sb);
1245			md_bitmap_free(bitmap);
1246			return -1;
1247		}
1248		kunmap_atomic(sb);
1249		md_bitmap_free(bitmap);
1250	}
1251
1252	return (my_sync_size == sync_size) ? 0 : -1;
1253}
1254
1255/*
1256 * Update the size for cluster raid is a little more complex, we perform it
1257 * by the steps:
1258 * 1. hold token lock and update superblock in initiator node.
1259 * 2. send METADATA_UPDATED msg to other nodes.
1260 * 3. The initiator node continues to check each bitmap's sync_size, if all
1261 *    bitmaps have the same value of sync_size, then we can set capacity and
1262 *    let other nodes to perform it. If one node can't update sync_size
1263 *    accordingly, we need to revert to previous value.
1264 */
1265static void update_size(struct mddev *mddev, sector_t old_dev_sectors)
1266{
1267	struct md_cluster_info *cinfo = mddev->cluster_info;
1268	struct cluster_msg cmsg;
1269	struct md_rdev *rdev;
1270	int ret = 0;
1271	int raid_slot = -1;
1272
1273	md_update_sb(mddev, 1);
1274	if (lock_comm(cinfo, 1)) {
1275		pr_err("%s: lock_comm failed\n", __func__);
1276		return;
1277	}
1278
1279	memset(&cmsg, 0, sizeof(cmsg));
1280	cmsg.type = cpu_to_le32(METADATA_UPDATED);
1281	rdev_for_each(rdev, mddev)
1282		if (rdev->raid_disk >= 0 && !test_bit(Faulty, &rdev->flags)) {
1283			raid_slot = rdev->desc_nr;
1284			break;
1285		}
1286	if (raid_slot >= 0) {
1287		cmsg.raid_slot = cpu_to_le32(raid_slot);
1288		/*
1289		 * We can only change capiticy after all the nodes can do it,
1290		 * so need to wait after other nodes already received the msg
1291		 * and handled the change
1292		 */
1293		ret = __sendmsg(cinfo, &cmsg);
1294		if (ret) {
1295			pr_err("%s:%d: failed to send METADATA_UPDATED msg\n",
1296			       __func__, __LINE__);
1297			unlock_comm(cinfo);
1298			return;
1299		}
1300	} else {
1301		pr_err("md-cluster: No good device id found to send\n");
1302		unlock_comm(cinfo);
1303		return;
1304	}
1305
1306	/*
1307	 * check the sync_size from other node's bitmap, if sync_size
1308	 * have already updated in other nodes as expected, send an
1309	 * empty metadata msg to permit the change of capacity
1310	 */
1311	if (cluster_check_sync_size(mddev) == 0) {
1312		memset(&cmsg, 0, sizeof(cmsg));
1313		cmsg.type = cpu_to_le32(CHANGE_CAPACITY);
1314		ret = __sendmsg(cinfo, &cmsg);
1315		if (ret)
1316			pr_err("%s:%d: failed to send CHANGE_CAPACITY msg\n",
1317			       __func__, __LINE__);
1318		set_capacity_and_notify(mddev->gendisk, mddev->array_sectors);
1319	} else {
1320		/* revert to previous sectors */
1321		ret = mddev->pers->resize(mddev, old_dev_sectors);
1322		ret = __sendmsg(cinfo, &cmsg);
1323		if (ret)
1324			pr_err("%s:%d: failed to send METADATA_UPDATED msg\n",
1325			       __func__, __LINE__);
1326	}
1327	unlock_comm(cinfo);
1328}
1329
1330static int resync_start(struct mddev *mddev)
1331{
1332	struct md_cluster_info *cinfo = mddev->cluster_info;
1333	return dlm_lock_sync_interruptible(cinfo->resync_lockres, DLM_LOCK_EX, mddev);
1334}
1335
1336static void resync_info_get(struct mddev *mddev, sector_t *lo, sector_t *hi)
1337{
1338	struct md_cluster_info *cinfo = mddev->cluster_info;
1339
1340	spin_lock_irq(&cinfo->suspend_lock);
1341	*lo = cinfo->suspend_lo;
1342	*hi = cinfo->suspend_hi;
1343	spin_unlock_irq(&cinfo->suspend_lock);
1344}
1345
1346static int resync_info_update(struct mddev *mddev, sector_t lo, sector_t hi)
1347{
1348	struct md_cluster_info *cinfo = mddev->cluster_info;
1349	struct resync_info ri;
1350	struct cluster_msg cmsg = {0};
1351
1352	/* do not send zero again, if we have sent before */
1353	if (hi == 0) {
1354		memcpy(&ri, cinfo->bitmap_lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
1355		if (le64_to_cpu(ri.hi) == 0)
1356			return 0;
1357	}
1358
1359	add_resync_info(cinfo->bitmap_lockres, lo, hi);
1360	/* Re-acquire the lock to refresh LVB */
1361	dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW);
1362	cmsg.type = cpu_to_le32(RESYNCING);
1363	cmsg.low = cpu_to_le64(lo);
1364	cmsg.high = cpu_to_le64(hi);
1365
1366	/*
1367	 * mddev_lock is held if resync_info_update is called from
1368	 * resync_finish (md_reap_sync_thread -> resync_finish)
1369	 */
1370	if (lo == 0 && hi == 0)
1371		return sendmsg(cinfo, &cmsg, 1);
1372	else
1373		return sendmsg(cinfo, &cmsg, 0);
1374}
1375
1376static int resync_finish(struct mddev *mddev)
1377{
1378	struct md_cluster_info *cinfo = mddev->cluster_info;
1379	int ret = 0;
1380
1381	clear_bit(MD_RESYNCING_REMOTE, &mddev->recovery);
1382
1383	/*
1384	 * If resync thread is interrupted so we can't say resync is finished,
1385	 * another node will launch resync thread to continue.
1386	 */
1387	if (!test_bit(MD_CLOSING, &mddev->flags))
1388		ret = resync_info_update(mddev, 0, 0);
1389	dlm_unlock_sync(cinfo->resync_lockres);
1390	return ret;
1391}
1392
1393static int area_resyncing(struct mddev *mddev, int direction,
1394		sector_t lo, sector_t hi)
1395{
1396	struct md_cluster_info *cinfo = mddev->cluster_info;
1397	int ret = 0;
 
1398
1399	if ((direction == READ) &&
1400		test_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state))
1401		return 1;
1402
1403	spin_lock_irq(&cinfo->suspend_lock);
1404	if (hi > cinfo->suspend_lo && lo < cinfo->suspend_hi)
1405		ret = 1;
 
 
 
 
 
 
1406	spin_unlock_irq(&cinfo->suspend_lock);
1407	return ret;
1408}
1409
1410/* add_new_disk() - initiates a disk add
1411 * However, if this fails before writing md_update_sb(),
1412 * add_new_disk_cancel() must be called to release token lock
1413 */
1414static int add_new_disk(struct mddev *mddev, struct md_rdev *rdev)
1415{
1416	struct md_cluster_info *cinfo = mddev->cluster_info;
1417	struct cluster_msg cmsg;
1418	int ret = 0;
1419	struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1420	char *uuid = sb->device_uuid;
1421
1422	memset(&cmsg, 0, sizeof(cmsg));
1423	cmsg.type = cpu_to_le32(NEWDISK);
1424	memcpy(cmsg.uuid, uuid, 16);
1425	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1426	if (lock_comm(cinfo, 1))
1427		return -EAGAIN;
1428	ret = __sendmsg(cinfo, &cmsg);
1429	if (ret) {
1430		unlock_comm(cinfo);
1431		return ret;
1432	}
1433	cinfo->no_new_dev_lockres->flags |= DLM_LKF_NOQUEUE;
1434	ret = dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_EX);
1435	cinfo->no_new_dev_lockres->flags &= ~DLM_LKF_NOQUEUE;
1436	/* Some node does not "see" the device */
1437	if (ret == -EAGAIN)
1438		ret = -ENOENT;
1439	if (ret)
1440		unlock_comm(cinfo);
1441	else {
1442		dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
1443		/* Since MD_CHANGE_DEVS will be set in add_bound_rdev which
1444		 * will run soon after add_new_disk, the below path will be
1445		 * invoked:
1446		 *   md_wakeup_thread(mddev->thread)
1447		 *	-> conf->thread (raid1d)
1448		 *	-> md_check_recovery -> md_update_sb
1449		 *	-> metadata_update_start/finish
1450		 * MD_CLUSTER_SEND_LOCKED_ALREADY will be cleared eventually.
1451		 *
1452		 * For other failure cases, metadata_update_cancel and
1453		 * add_new_disk_cancel also clear below bit as well.
1454		 * */
1455		set_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1456		wake_up(&cinfo->wait);
1457	}
1458	return ret;
1459}
1460
1461static void add_new_disk_cancel(struct mddev *mddev)
1462{
1463	struct md_cluster_info *cinfo = mddev->cluster_info;
1464	clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1465	unlock_comm(cinfo);
1466}
1467
1468static int new_disk_ack(struct mddev *mddev, bool ack)
1469{
1470	struct md_cluster_info *cinfo = mddev->cluster_info;
1471
1472	if (!test_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state)) {
1473		pr_warn("md-cluster(%s): Spurious cluster confirmation\n", mdname(mddev));
1474		return -EINVAL;
1475	}
1476
1477	if (ack)
1478		dlm_unlock_sync(cinfo->no_new_dev_lockres);
1479	complete(&cinfo->newdisk_completion);
1480	return 0;
1481}
1482
1483static int remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1484{
1485	struct cluster_msg cmsg = {0};
1486	struct md_cluster_info *cinfo = mddev->cluster_info;
1487	cmsg.type = cpu_to_le32(REMOVE);
1488	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1489	return sendmsg(cinfo, &cmsg, 1);
1490}
1491
1492static int lock_all_bitmaps(struct mddev *mddev)
1493{
1494	int slot, my_slot, ret, held = 1, i = 0;
1495	char str[64];
1496	struct md_cluster_info *cinfo = mddev->cluster_info;
1497
1498	cinfo->other_bitmap_lockres =
1499		kcalloc(mddev->bitmap_info.nodes - 1,
1500			sizeof(struct dlm_lock_resource *), GFP_KERNEL);
1501	if (!cinfo->other_bitmap_lockres) {
1502		pr_err("md: can't alloc mem for other bitmap locks\n");
1503		return 0;
1504	}
1505
1506	my_slot = slot_number(mddev);
1507	for (slot = 0; slot < mddev->bitmap_info.nodes; slot++) {
1508		if (slot == my_slot)
1509			continue;
1510
1511		memset(str, '\0', 64);
1512		snprintf(str, 64, "bitmap%04d", slot);
1513		cinfo->other_bitmap_lockres[i] = lockres_init(mddev, str, NULL, 1);
1514		if (!cinfo->other_bitmap_lockres[i])
1515			return -ENOMEM;
1516
1517		cinfo->other_bitmap_lockres[i]->flags |= DLM_LKF_NOQUEUE;
1518		ret = dlm_lock_sync(cinfo->other_bitmap_lockres[i], DLM_LOCK_PW);
1519		if (ret)
1520			held = -1;
1521		i++;
1522	}
1523
1524	return held;
1525}
1526
1527static void unlock_all_bitmaps(struct mddev *mddev)
1528{
1529	struct md_cluster_info *cinfo = mddev->cluster_info;
1530	int i;
1531
1532	/* release other node's bitmap lock if they are existed */
1533	if (cinfo->other_bitmap_lockres) {
1534		for (i = 0; i < mddev->bitmap_info.nodes - 1; i++) {
1535			if (cinfo->other_bitmap_lockres[i]) {
 
1536				lockres_free(cinfo->other_bitmap_lockres[i]);
1537			}
1538		}
1539		kfree(cinfo->other_bitmap_lockres);
1540		cinfo->other_bitmap_lockres = NULL;
1541	}
1542}
1543
1544static int gather_bitmaps(struct md_rdev *rdev)
1545{
1546	int sn, err;
1547	sector_t lo, hi;
1548	struct cluster_msg cmsg = {0};
1549	struct mddev *mddev = rdev->mddev;
1550	struct md_cluster_info *cinfo = mddev->cluster_info;
1551
1552	cmsg.type = cpu_to_le32(RE_ADD);
1553	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1554	err = sendmsg(cinfo, &cmsg, 1);
1555	if (err)
1556		goto out;
1557
1558	for (sn = 0; sn < mddev->bitmap_info.nodes; sn++) {
1559		if (sn == (cinfo->slot_number - 1))
1560			continue;
1561		err = md_bitmap_copy_from_slot(mddev, sn, &lo, &hi, false);
1562		if (err) {
1563			pr_warn("md-cluster: Could not gather bitmaps from slot %d", sn);
1564			goto out;
1565		}
1566		if ((hi > 0) && (lo < mddev->recovery_cp))
1567			mddev->recovery_cp = lo;
1568	}
1569out:
1570	return err;
1571}
1572
1573static struct md_cluster_operations cluster_ops = {
1574	.join   = join,
1575	.leave  = leave,
1576	.slot_number = slot_number,
1577	.resync_start = resync_start,
1578	.resync_finish = resync_finish,
1579	.resync_info_update = resync_info_update,
1580	.resync_info_get = resync_info_get,
1581	.metadata_update_start = metadata_update_start,
1582	.metadata_update_finish = metadata_update_finish,
1583	.metadata_update_cancel = metadata_update_cancel,
1584	.area_resyncing = area_resyncing,
1585	.add_new_disk = add_new_disk,
1586	.add_new_disk_cancel = add_new_disk_cancel,
1587	.new_disk_ack = new_disk_ack,
1588	.remove_disk = remove_disk,
1589	.load_bitmaps = load_bitmaps,
1590	.gather_bitmaps = gather_bitmaps,
1591	.resize_bitmaps = resize_bitmaps,
1592	.lock_all_bitmaps = lock_all_bitmaps,
1593	.unlock_all_bitmaps = unlock_all_bitmaps,
1594	.update_size = update_size,
1595};
1596
1597static int __init cluster_init(void)
1598{
1599	pr_warn("md-cluster: support raid1 and raid10 (limited support)\n");
1600	pr_info("Registering Cluster MD functions\n");
1601	register_md_cluster_operations(&cluster_ops, THIS_MODULE);
1602	return 0;
1603}
1604
1605static void cluster_exit(void)
1606{
1607	unregister_md_cluster_operations();
1608}
1609
1610module_init(cluster_init);
1611module_exit(cluster_exit);
1612MODULE_AUTHOR("SUSE");
1613MODULE_LICENSE("GPL");
1614MODULE_DESCRIPTION("Clustering support for MD");
v4.6
 
   1/*
   2 * Copyright (C) 2015, SUSE
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License as published by
   6 * the Free Software Foundation; either version 2, or (at your option)
   7 * any later version.
   8 *
   9 */
  10
  11
  12#include <linux/module.h>
 
  13#include <linux/dlm.h>
  14#include <linux/sched.h>
  15#include <linux/raid/md_p.h>
  16#include "md.h"
  17#include "bitmap.h"
  18#include "md-cluster.h"
  19
  20#define LVB_SIZE	64
  21#define NEW_DEV_TIMEOUT 5000
  22
  23struct dlm_lock_resource {
  24	dlm_lockspace_t *ls;
  25	struct dlm_lksb lksb;
  26	char *name; /* lock name. */
  27	uint32_t flags; /* flags to pass to dlm_lock() */
  28	struct completion completion; /* completion for synchronized locking */
 
  29	void (*bast)(void *arg, int mode); /* blocking AST function pointer*/
  30	struct mddev *mddev; /* pointing back to mddev. */
  31	int mode;
  32};
  33
  34struct suspend_info {
  35	int slot;
  36	sector_t lo;
  37	sector_t hi;
  38	struct list_head list;
  39};
  40
  41struct resync_info {
  42	__le64 lo;
  43	__le64 hi;
  44};
  45
  46/* md_cluster_info flags */
  47#define		MD_CLUSTER_WAITING_FOR_NEWDISK		1
  48#define		MD_CLUSTER_SUSPEND_READ_BALANCING	2
  49#define		MD_CLUSTER_BEGIN_JOIN_CLUSTER		3
  50
  51/* Lock the send communication. This is done through
  52 * bit manipulation as opposed to a mutex in order to
  53 * accomodate lock and hold. See next comment.
  54 */
  55#define		MD_CLUSTER_SEND_LOCK			4
  56/* If cluster operations (such as adding a disk) must lock the
  57 * communication channel, so as to perform extra operations
  58 * (update metadata) and no other operation is allowed on the
  59 * MD. Token needs to be locked and held until the operation
  60 * completes witha md_update_sb(), which would eventually release
  61 * the lock.
  62 */
  63#define		MD_CLUSTER_SEND_LOCKED_ALREADY		5
  64
 
 
 
 
  65
  66struct md_cluster_info {
 
  67	/* dlm lock space and resources for clustered raid. */
  68	dlm_lockspace_t *lockspace;
  69	int slot_number;
  70	struct completion completion;
  71	struct mutex recv_mutex;
  72	struct dlm_lock_resource *bitmap_lockres;
  73	struct dlm_lock_resource **other_bitmap_lockres;
  74	struct dlm_lock_resource *resync_lockres;
  75	struct list_head suspend_list;
 
  76	spinlock_t suspend_lock;
  77	struct md_thread *recovery_thread;
 
 
 
 
 
  78	unsigned long recovery_map;
  79	/* communication loc resources */
  80	struct dlm_lock_resource *ack_lockres;
  81	struct dlm_lock_resource *message_lockres;
  82	struct dlm_lock_resource *token_lockres;
  83	struct dlm_lock_resource *no_new_dev_lockres;
  84	struct md_thread *recv_thread;
  85	struct completion newdisk_completion;
  86	wait_queue_head_t wait;
  87	unsigned long state;
 
 
 
  88};
  89
  90enum msg_type {
  91	METADATA_UPDATED = 0,
  92	RESYNCING,
  93	NEWDISK,
  94	REMOVE,
  95	RE_ADD,
  96	BITMAP_NEEDS_SYNC,
 
 
  97};
  98
  99struct cluster_msg {
 100	__le32 type;
 101	__le32 slot;
 102	/* TODO: Unionize this for smaller footprint */
 103	__le64 low;
 104	__le64 high;
 105	char uuid[16];
 106	__le32 raid_slot;
 107};
 108
 109static void sync_ast(void *arg)
 110{
 111	struct dlm_lock_resource *res;
 112
 113	res = arg;
 114	complete(&res->completion);
 
 115}
 116
 117static int dlm_lock_sync(struct dlm_lock_resource *res, int mode)
 118{
 119	int ret = 0;
 120
 121	ret = dlm_lock(res->ls, mode, &res->lksb,
 122			res->flags, res->name, strlen(res->name),
 123			0, sync_ast, res, res->bast);
 124	if (ret)
 125		return ret;
 126	wait_for_completion(&res->completion);
 
 127	if (res->lksb.sb_status == 0)
 128		res->mode = mode;
 129	return res->lksb.sb_status;
 130}
 131
 132static int dlm_unlock_sync(struct dlm_lock_resource *res)
 133{
 134	return dlm_lock_sync(res, DLM_LOCK_NL);
 135}
 136
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 137static struct dlm_lock_resource *lockres_init(struct mddev *mddev,
 138		char *name, void (*bastfn)(void *arg, int mode), int with_lvb)
 139{
 140	struct dlm_lock_resource *res = NULL;
 141	int ret, namelen;
 142	struct md_cluster_info *cinfo = mddev->cluster_info;
 143
 144	res = kzalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL);
 145	if (!res)
 146		return NULL;
 147	init_completion(&res->completion);
 
 148	res->ls = cinfo->lockspace;
 149	res->mddev = mddev;
 150	res->mode = DLM_LOCK_IV;
 151	namelen = strlen(name);
 152	res->name = kzalloc(namelen + 1, GFP_KERNEL);
 153	if (!res->name) {
 154		pr_err("md-cluster: Unable to allocate resource name for resource %s\n", name);
 155		goto out_err;
 156	}
 157	strlcpy(res->name, name, namelen + 1);
 158	if (with_lvb) {
 159		res->lksb.sb_lvbptr = kzalloc(LVB_SIZE, GFP_KERNEL);
 160		if (!res->lksb.sb_lvbptr) {
 161			pr_err("md-cluster: Unable to allocate LVB for resource %s\n", name);
 162			goto out_err;
 163		}
 164		res->flags = DLM_LKF_VALBLK;
 165	}
 166
 167	if (bastfn)
 168		res->bast = bastfn;
 169
 170	res->flags |= DLM_LKF_EXPEDITE;
 171
 172	ret = dlm_lock_sync(res, DLM_LOCK_NL);
 173	if (ret) {
 174		pr_err("md-cluster: Unable to lock NL on new lock resource %s\n", name);
 175		goto out_err;
 176	}
 177	res->flags &= ~DLM_LKF_EXPEDITE;
 178	res->flags |= DLM_LKF_CONVERT;
 179
 180	return res;
 181out_err:
 182	kfree(res->lksb.sb_lvbptr);
 183	kfree(res->name);
 184	kfree(res);
 185	return NULL;
 186}
 187
 188static void lockres_free(struct dlm_lock_resource *res)
 189{
 190	int ret;
 191
 192	if (!res)
 193		return;
 194
 195	/* cancel a lock request or a conversion request that is blocked */
 196	res->flags |= DLM_LKF_CANCEL;
 197retry:
 198	ret = dlm_unlock(res->ls, res->lksb.sb_lkid, 0, &res->lksb, res);
 199	if (unlikely(ret != 0)) {
 200		pr_info("%s: failed to unlock %s return %d\n", __func__, res->name, ret);
 201
 202		/* if a lock conversion is cancelled, then the lock is put
 203		 * back to grant queue, need to ensure it is unlocked */
 204		if (ret == -DLM_ECANCEL)
 205			goto retry;
 206	}
 207	res->flags &= ~DLM_LKF_CANCEL;
 208	wait_for_completion(&res->completion);
 209
 210	kfree(res->name);
 211	kfree(res->lksb.sb_lvbptr);
 212	kfree(res);
 213}
 214
 215static void add_resync_info(struct dlm_lock_resource *lockres,
 216			    sector_t lo, sector_t hi)
 217{
 218	struct resync_info *ri;
 219
 220	ri = (struct resync_info *)lockres->lksb.sb_lvbptr;
 221	ri->lo = cpu_to_le64(lo);
 222	ri->hi = cpu_to_le64(hi);
 223}
 224
 225static struct suspend_info *read_resync_info(struct mddev *mddev, struct dlm_lock_resource *lockres)
 
 226{
 227	struct resync_info ri;
 228	struct suspend_info *s = NULL;
 229	sector_t hi = 0;
 230
 231	dlm_lock_sync(lockres, DLM_LOCK_CR);
 232	memcpy(&ri, lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
 233	hi = le64_to_cpu(ri.hi);
 234	if (hi > 0) {
 235		s = kzalloc(sizeof(struct suspend_info), GFP_KERNEL);
 236		if (!s)
 237			goto out;
 238		s->hi = hi;
 239		s->lo = le64_to_cpu(ri.lo);
 240	}
 241	dlm_unlock_sync(lockres);
 242out:
 243	return s;
 244}
 245
 246static void recover_bitmaps(struct md_thread *thread)
 247{
 248	struct mddev *mddev = thread->mddev;
 249	struct md_cluster_info *cinfo = mddev->cluster_info;
 250	struct dlm_lock_resource *bm_lockres;
 251	char str[64];
 252	int slot, ret;
 253	struct suspend_info *s, *tmp;
 254	sector_t lo, hi;
 255
 256	while (cinfo->recovery_map) {
 257		slot = fls64((u64)cinfo->recovery_map) - 1;
 258
 259		/* Clear suspend_area associated with the bitmap */
 260		spin_lock_irq(&cinfo->suspend_lock);
 261		list_for_each_entry_safe(s, tmp, &cinfo->suspend_list, list)
 262			if (slot == s->slot) {
 263				list_del(&s->list);
 264				kfree(s);
 265			}
 266		spin_unlock_irq(&cinfo->suspend_lock);
 267
 268		snprintf(str, 64, "bitmap%04d", slot);
 269		bm_lockres = lockres_init(mddev, str, NULL, 1);
 270		if (!bm_lockres) {
 271			pr_err("md-cluster: Cannot initialize bitmaps\n");
 272			goto clear_bit;
 273		}
 274
 275		ret = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
 276		if (ret) {
 277			pr_err("md-cluster: Could not DLM lock %s: %d\n",
 278					str, ret);
 279			goto clear_bit;
 280		}
 281		ret = bitmap_copy_from_slot(mddev, slot, &lo, &hi, true);
 282		if (ret) {
 283			pr_err("md-cluster: Could not copy data from bitmap %d\n", slot);
 284			goto dlm_unlock;
 285		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 286		if (hi > 0) {
 287			/* TODO:Wait for current resync to get over */
 288			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 289			if (lo < mddev->recovery_cp)
 290				mddev->recovery_cp = lo;
 291			md_check_recovery(mddev);
 
 
 
 
 
 
 
 
 
 
 
 292		}
 293dlm_unlock:
 294		dlm_unlock_sync(bm_lockres);
 295clear_bit:
 296		lockres_free(bm_lockres);
 297		clear_bit(slot, &cinfo->recovery_map);
 298	}
 299}
 300
 301static void recover_prep(void *arg)
 302{
 303	struct mddev *mddev = arg;
 304	struct md_cluster_info *cinfo = mddev->cluster_info;
 305	set_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state);
 306}
 307
 308static void __recover_slot(struct mddev *mddev, int slot)
 309{
 310	struct md_cluster_info *cinfo = mddev->cluster_info;
 311
 312	set_bit(slot, &cinfo->recovery_map);
 313	if (!cinfo->recovery_thread) {
 314		cinfo->recovery_thread = md_register_thread(recover_bitmaps,
 315				mddev, "recover");
 316		if (!cinfo->recovery_thread) {
 317			pr_warn("md-cluster: Could not create recovery thread\n");
 318			return;
 319		}
 320	}
 321	md_wakeup_thread(cinfo->recovery_thread);
 322}
 323
 324static void recover_slot(void *arg, struct dlm_slot *slot)
 325{
 326	struct mddev *mddev = arg;
 327	struct md_cluster_info *cinfo = mddev->cluster_info;
 328
 329	pr_info("md-cluster: %s Node %d/%d down. My slot: %d. Initiating recovery.\n",
 330			mddev->bitmap_info.cluster_name,
 331			slot->nodeid, slot->slot,
 332			cinfo->slot_number);
 333	/* deduct one since dlm slot starts from one while the num of
 334	 * cluster-md begins with 0 */
 335	__recover_slot(mddev, slot->slot - 1);
 336}
 337
 338static void recover_done(void *arg, struct dlm_slot *slots,
 339		int num_slots, int our_slot,
 340		uint32_t generation)
 341{
 342	struct mddev *mddev = arg;
 343	struct md_cluster_info *cinfo = mddev->cluster_info;
 344
 345	cinfo->slot_number = our_slot;
 346	/* completion is only need to be complete when node join cluster,
 347	 * it doesn't need to run during another node's failure */
 348	if (test_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state)) {
 349		complete(&cinfo->completion);
 350		clear_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state);
 351	}
 352	clear_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state);
 353}
 354
 355/* the ops is called when node join the cluster, and do lock recovery
 356 * if node failure occurs */
 357static const struct dlm_lockspace_ops md_ls_ops = {
 358	.recover_prep = recover_prep,
 359	.recover_slot = recover_slot,
 360	.recover_done = recover_done,
 361};
 362
 363/*
 364 * The BAST function for the ack lock resource
 365 * This function wakes up the receive thread in
 366 * order to receive and process the message.
 367 */
 368static void ack_bast(void *arg, int mode)
 369{
 370	struct dlm_lock_resource *res = arg;
 371	struct md_cluster_info *cinfo = res->mddev->cluster_info;
 372
 373	if (mode == DLM_LOCK_EX)
 374		md_wakeup_thread(cinfo->recv_thread);
 375}
 376
 377static void __remove_suspend_info(struct md_cluster_info *cinfo, int slot)
 378{
 379	struct suspend_info *s, *tmp;
 380
 381	list_for_each_entry_safe(s, tmp, &cinfo->suspend_list, list)
 382		if (slot == s->slot) {
 383			list_del(&s->list);
 384			kfree(s);
 385			break;
 386		}
 387}
 388
 389static void remove_suspend_info(struct mddev *mddev, int slot)
 390{
 391	struct md_cluster_info *cinfo = mddev->cluster_info;
 
 392	spin_lock_irq(&cinfo->suspend_lock);
 393	__remove_suspend_info(cinfo, slot);
 
 394	spin_unlock_irq(&cinfo->suspend_lock);
 395	mddev->pers->quiesce(mddev, 2);
 396}
 397
 398
 399static void process_suspend_info(struct mddev *mddev,
 400		int slot, sector_t lo, sector_t hi)
 401{
 402	struct md_cluster_info *cinfo = mddev->cluster_info;
 403	struct suspend_info *s;
 
 404
 405	if (!hi) {
 
 
 
 
 
 406		remove_suspend_info(mddev, slot);
 407		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 408		md_wakeup_thread(mddev->thread);
 409		return;
 410	}
 411	s = kzalloc(sizeof(struct suspend_info), GFP_KERNEL);
 412	if (!s)
 413		return;
 414	s->slot = slot;
 415	s->lo = lo;
 416	s->hi = hi;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 417	mddev->pers->quiesce(mddev, 1);
 418	mddev->pers->quiesce(mddev, 0);
 419	spin_lock_irq(&cinfo->suspend_lock);
 420	/* Remove existing entry (if exists) before adding */
 421	__remove_suspend_info(cinfo, slot);
 422	list_add(&s->list, &cinfo->suspend_list);
 423	spin_unlock_irq(&cinfo->suspend_lock);
 424	mddev->pers->quiesce(mddev, 2);
 425}
 426
 427static void process_add_new_disk(struct mddev *mddev, struct cluster_msg *cmsg)
 428{
 429	char disk_uuid[64];
 430	struct md_cluster_info *cinfo = mddev->cluster_info;
 431	char event_name[] = "EVENT=ADD_DEVICE";
 432	char raid_slot[16];
 433	char *envp[] = {event_name, disk_uuid, raid_slot, NULL};
 434	int len;
 
 435
 436	len = snprintf(disk_uuid, 64, "DEVICE_UUID=");
 437	sprintf(disk_uuid + len, "%pU", cmsg->uuid);
 438	snprintf(raid_slot, 16, "RAID_DISK=%d", le32_to_cpu(cmsg->raid_slot));
 439	pr_info("%s:%d Sending kobject change with %s and %s\n", __func__, __LINE__, disk_uuid, raid_slot);
 440	init_completion(&cinfo->newdisk_completion);
 441	set_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state);
 442	kobject_uevent_env(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE, envp);
 443	wait_for_completion_timeout(&cinfo->newdisk_completion,
 444			NEW_DEV_TIMEOUT);
 
 
 
 
 445	clear_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state);
 
 446}
 447
 448
 449static void process_metadata_update(struct mddev *mddev, struct cluster_msg *msg)
 450{
 
 
 451	struct md_cluster_info *cinfo = mddev->cluster_info;
 452	mddev->good_device_nr = le32_to_cpu(msg->raid_slot);
 453	set_bit(MD_RELOAD_SB, &mddev->flags);
 454	dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
 455	md_wakeup_thread(mddev->thread);
 
 
 
 
 
 
 
 
 456}
 457
 458static void process_remove_disk(struct mddev *mddev, struct cluster_msg *msg)
 459{
 460	struct md_rdev *rdev = md_find_rdev_nr_rcu(mddev,
 461						   le32_to_cpu(msg->raid_slot));
 462
 
 
 463	if (rdev) {
 464		set_bit(ClusterRemove, &rdev->flags);
 465		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 466		md_wakeup_thread(mddev->thread);
 467	}
 468	else
 469		pr_warn("%s: %d Could not find disk(%d) to REMOVE\n",
 470			__func__, __LINE__, le32_to_cpu(msg->raid_slot));
 
 471}
 472
 473static void process_readd_disk(struct mddev *mddev, struct cluster_msg *msg)
 474{
 475	struct md_rdev *rdev = md_find_rdev_nr_rcu(mddev,
 476						   le32_to_cpu(msg->raid_slot));
 477
 
 
 478	if (rdev && test_bit(Faulty, &rdev->flags))
 479		clear_bit(Faulty, &rdev->flags);
 480	else
 481		pr_warn("%s: %d Could not find disk(%d) which is faulty",
 482			__func__, __LINE__, le32_to_cpu(msg->raid_slot));
 
 483}
 484
 485static void process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
 486{
 
 
 487	if (WARN(mddev->cluster_info->slot_number - 1 == le32_to_cpu(msg->slot),
 488		"node %d received it's own msg\n", le32_to_cpu(msg->slot)))
 489		return;
 490	switch (le32_to_cpu(msg->type)) {
 491	case METADATA_UPDATED:
 492		process_metadata_update(mddev, msg);
 493		break;
 
 
 
 494	case RESYNCING:
 
 495		process_suspend_info(mddev, le32_to_cpu(msg->slot),
 496				     le64_to_cpu(msg->low),
 497				     le64_to_cpu(msg->high));
 498		break;
 499	case NEWDISK:
 500		process_add_new_disk(mddev, msg);
 
 501		break;
 502	case REMOVE:
 503		process_remove_disk(mddev, msg);
 504		break;
 505	case RE_ADD:
 506		process_readd_disk(mddev, msg);
 507		break;
 508	case BITMAP_NEEDS_SYNC:
 509		__recover_slot(mddev, le32_to_cpu(msg->slot));
 510		break;
 
 
 
 
 
 511	default:
 
 512		pr_warn("%s:%d Received unknown message from %d\n",
 513			__func__, __LINE__, msg->slot);
 514	}
 
 515}
 516
 517/*
 518 * thread for receiving message
 519 */
 520static void recv_daemon(struct md_thread *thread)
 521{
 522	struct md_cluster_info *cinfo = thread->mddev->cluster_info;
 523	struct dlm_lock_resource *ack_lockres = cinfo->ack_lockres;
 524	struct dlm_lock_resource *message_lockres = cinfo->message_lockres;
 525	struct cluster_msg msg;
 526	int ret;
 527
 528	mutex_lock(&cinfo->recv_mutex);
 529	/*get CR on Message*/
 530	if (dlm_lock_sync(message_lockres, DLM_LOCK_CR)) {
 531		pr_err("md/raid1:failed to get CR on MESSAGE\n");
 532		mutex_unlock(&cinfo->recv_mutex);
 533		return;
 534	}
 535
 536	/* read lvb and wake up thread to process this message_lockres */
 537	memcpy(&msg, message_lockres->lksb.sb_lvbptr, sizeof(struct cluster_msg));
 538	process_recvd_msg(thread->mddev, &msg);
 
 
 539
 540	/*release CR on ack_lockres*/
 541	ret = dlm_unlock_sync(ack_lockres);
 542	if (unlikely(ret != 0))
 543		pr_info("unlock ack failed return %d\n", ret);
 544	/*up-convert to PR on message_lockres*/
 545	ret = dlm_lock_sync(message_lockres, DLM_LOCK_PR);
 546	if (unlikely(ret != 0))
 547		pr_info("lock PR on msg failed return %d\n", ret);
 548	/*get CR on ack_lockres again*/
 549	ret = dlm_lock_sync(ack_lockres, DLM_LOCK_CR);
 550	if (unlikely(ret != 0))
 551		pr_info("lock CR on ack failed return %d\n", ret);
 
 552	/*release CR on message_lockres*/
 553	ret = dlm_unlock_sync(message_lockres);
 554	if (unlikely(ret != 0))
 555		pr_info("unlock msg failed return %d\n", ret);
 556	mutex_unlock(&cinfo->recv_mutex);
 557}
 558
 559/* lock_token()
 560 * Takes the lock on the TOKEN lock resource so no other
 561 * node can communicate while the operation is underway.
 562 */
 563static int lock_token(struct md_cluster_info *cinfo)
 564{
 565	int error;
 566
 567	error = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
 568	if (error)
 569		pr_err("md-cluster(%s:%d): failed to get EX on TOKEN (%d)\n",
 570				__func__, __LINE__, error);
 571
 572	/* Lock the receive sequence */
 573	mutex_lock(&cinfo->recv_mutex);
 
 574	return error;
 575}
 576
 577/* lock_comm()
 578 * Sets the MD_CLUSTER_SEND_LOCK bit to lock the send channel.
 579 */
 580static int lock_comm(struct md_cluster_info *cinfo)
 581{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 582	wait_event(cinfo->wait,
 583		   !test_and_set_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state));
 584
 585	return lock_token(cinfo);
 
 
 586}
 587
 588static void unlock_comm(struct md_cluster_info *cinfo)
 589{
 590	WARN_ON(cinfo->token_lockres->mode != DLM_LOCK_EX);
 591	mutex_unlock(&cinfo->recv_mutex);
 592	dlm_unlock_sync(cinfo->token_lockres);
 593	clear_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state);
 594	wake_up(&cinfo->wait);
 595}
 596
 597/* __sendmsg()
 598 * This function performs the actual sending of the message. This function is
 599 * usually called after performing the encompassing operation
 600 * The function:
 601 * 1. Grabs the message lockresource in EX mode
 602 * 2. Copies the message to the message LVB
 603 * 3. Downconverts message lockresource to CW
 604 * 4. Upconverts ack lock resource from CR to EX. This forces the BAST on other nodes
 605 *    and the other nodes read the message. The thread will wait here until all other
 606 *    nodes have released ack lock resource.
 607 * 5. Downconvert ack lockresource to CR
 608 */
 609static int __sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg)
 610{
 611	int error;
 612	int slot = cinfo->slot_number - 1;
 613
 614	cmsg->slot = cpu_to_le32(slot);
 615	/*get EX on Message*/
 616	error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_EX);
 617	if (error) {
 618		pr_err("md-cluster: failed to get EX on MESSAGE (%d)\n", error);
 619		goto failed_message;
 620	}
 621
 622	memcpy(cinfo->message_lockres->lksb.sb_lvbptr, (void *)cmsg,
 623			sizeof(struct cluster_msg));
 624	/*down-convert EX to CW on Message*/
 625	error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_CW);
 626	if (error) {
 627		pr_err("md-cluster: failed to convert EX to CW on MESSAGE(%d)\n",
 628				error);
 629		goto failed_ack;
 630	}
 631
 632	/*up-convert CR to EX on Ack*/
 633	error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_EX);
 634	if (error) {
 635		pr_err("md-cluster: failed to convert CR to EX on ACK(%d)\n",
 636				error);
 637		goto failed_ack;
 638	}
 639
 640	/*down-convert EX to CR on Ack*/
 641	error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR);
 642	if (error) {
 643		pr_err("md-cluster: failed to convert EX to CR on ACK(%d)\n",
 644				error);
 645		goto failed_ack;
 646	}
 647
 648failed_ack:
 649	error = dlm_unlock_sync(cinfo->message_lockres);
 650	if (unlikely(error != 0)) {
 651		pr_err("md-cluster: failed convert to NL on MESSAGE(%d)\n",
 652			error);
 653		/* in case the message can't be released due to some reason */
 654		goto failed_ack;
 655	}
 656failed_message:
 657	return error;
 658}
 659
 660static int sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg)
 
 661{
 662	int ret;
 663
 664	lock_comm(cinfo);
 665	ret = __sendmsg(cinfo, cmsg);
 666	unlock_comm(cinfo);
 
 
 667	return ret;
 668}
 669
 670static int gather_all_resync_info(struct mddev *mddev, int total_slots)
 671{
 672	struct md_cluster_info *cinfo = mddev->cluster_info;
 673	int i, ret = 0;
 674	struct dlm_lock_resource *bm_lockres;
 675	struct suspend_info *s;
 676	char str[64];
 677	sector_t lo, hi;
 678
 679
 680	for (i = 0; i < total_slots; i++) {
 681		memset(str, '\0', 64);
 682		snprintf(str, 64, "bitmap%04d", i);
 683		bm_lockres = lockres_init(mddev, str, NULL, 1);
 684		if (!bm_lockres)
 685			return -ENOMEM;
 686		if (i == (cinfo->slot_number - 1)) {
 687			lockres_free(bm_lockres);
 688			continue;
 689		}
 690
 691		bm_lockres->flags |= DLM_LKF_NOQUEUE;
 692		ret = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
 693		if (ret == -EAGAIN) {
 694			memset(bm_lockres->lksb.sb_lvbptr, '\0', LVB_SIZE);
 695			s = read_resync_info(mddev, bm_lockres);
 696			if (s) {
 697				pr_info("%s:%d Resync[%llu..%llu] in progress on %d\n",
 698						__func__, __LINE__,
 699						(unsigned long long) s->lo,
 700						(unsigned long long) s->hi, i);
 701				spin_lock_irq(&cinfo->suspend_lock);
 702				s->slot = i;
 703				list_add(&s->list, &cinfo->suspend_list);
 704				spin_unlock_irq(&cinfo->suspend_lock);
 705			}
 706			ret = 0;
 707			lockres_free(bm_lockres);
 708			continue;
 709		}
 710		if (ret) {
 711			lockres_free(bm_lockres);
 712			goto out;
 713		}
 714
 715		/* Read the disk bitmap sb and check if it needs recovery */
 716		ret = bitmap_copy_from_slot(mddev, i, &lo, &hi, false);
 717		if (ret) {
 718			pr_warn("md-cluster: Could not gather bitmaps from slot %d", i);
 719			lockres_free(bm_lockres);
 720			continue;
 721		}
 722		if ((hi > 0) && (lo < mddev->recovery_cp)) {
 723			set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 724			mddev->recovery_cp = lo;
 725			md_check_recovery(mddev);
 726		}
 727
 728		dlm_unlock_sync(bm_lockres);
 729		lockres_free(bm_lockres);
 730	}
 731out:
 732	return ret;
 733}
 734
 735static int join(struct mddev *mddev, int nodes)
 736{
 737	struct md_cluster_info *cinfo;
 738	int ret, ops_rv;
 739	char str[64];
 740
 741	cinfo = kzalloc(sizeof(struct md_cluster_info), GFP_KERNEL);
 742	if (!cinfo)
 743		return -ENOMEM;
 744
 745	INIT_LIST_HEAD(&cinfo->suspend_list);
 746	spin_lock_init(&cinfo->suspend_lock);
 747	init_completion(&cinfo->completion);
 748	set_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state);
 749	init_waitqueue_head(&cinfo->wait);
 750	mutex_init(&cinfo->recv_mutex);
 751
 752	mddev->cluster_info = cinfo;
 
 753
 754	memset(str, 0, 64);
 755	sprintf(str, "%pU", mddev->uuid);
 756	ret = dlm_new_lockspace(str, mddev->bitmap_info.cluster_name,
 757				DLM_LSFL_FS, LVB_SIZE,
 758				&md_ls_ops, mddev, &ops_rv, &cinfo->lockspace);
 759	if (ret)
 760		goto err;
 761	wait_for_completion(&cinfo->completion);
 762	if (nodes < cinfo->slot_number) {
 763		pr_err("md-cluster: Slot allotted(%d) is greater than available slots(%d).",
 764			cinfo->slot_number, nodes);
 765		ret = -ERANGE;
 766		goto err;
 767	}
 768	/* Initiate the communication resources */
 769	ret = -ENOMEM;
 770	cinfo->recv_thread = md_register_thread(recv_daemon, mddev, "cluster_recv");
 
 771	if (!cinfo->recv_thread) {
 772		pr_err("md-cluster: cannot allocate memory for recv_thread!\n");
 773		goto err;
 774	}
 775	cinfo->message_lockres = lockres_init(mddev, "message", NULL, 1);
 776	if (!cinfo->message_lockres)
 777		goto err;
 778	cinfo->token_lockres = lockres_init(mddev, "token", NULL, 0);
 779	if (!cinfo->token_lockres)
 780		goto err;
 781	cinfo->ack_lockres = lockres_init(mddev, "ack", ack_bast, 0);
 782	if (!cinfo->ack_lockres)
 783		goto err;
 784	cinfo->no_new_dev_lockres = lockres_init(mddev, "no-new-dev", NULL, 0);
 785	if (!cinfo->no_new_dev_lockres)
 786		goto err;
 787
 
 
 
 
 
 
 
 
 
 
 
 788	/* get sync CR lock on ACK. */
 789	if (dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR))
 790		pr_err("md-cluster: failed to get a sync CR lock on ACK!(%d)\n",
 791				ret);
 
 792	/* get sync CR lock on no-new-dev. */
 793	if (dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR))
 794		pr_err("md-cluster: failed to get a sync CR lock on no-new-dev!(%d)\n", ret);
 795
 796
 797	pr_info("md-cluster: Joined cluster %s slot %d\n", str, cinfo->slot_number);
 798	snprintf(str, 64, "bitmap%04d", cinfo->slot_number - 1);
 799	cinfo->bitmap_lockres = lockres_init(mddev, str, NULL, 1);
 800	if (!cinfo->bitmap_lockres)
 
 801		goto err;
 
 802	if (dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW)) {
 803		pr_err("Failed to get bitmap lock\n");
 804		ret = -EINVAL;
 805		goto err;
 806	}
 807
 808	cinfo->resync_lockres = lockres_init(mddev, "resync", NULL, 0);
 809	if (!cinfo->resync_lockres)
 810		goto err;
 811
 812	ret = gather_all_resync_info(mddev, nodes);
 813	if (ret)
 814		goto err;
 
 815
 816	return 0;
 817err:
 
 
 
 818	lockres_free(cinfo->message_lockres);
 819	lockres_free(cinfo->token_lockres);
 820	lockres_free(cinfo->ack_lockres);
 821	lockres_free(cinfo->no_new_dev_lockres);
 822	lockres_free(cinfo->resync_lockres);
 823	lockres_free(cinfo->bitmap_lockres);
 824	if (cinfo->lockspace)
 825		dlm_release_lockspace(cinfo->lockspace, 2);
 826	mddev->cluster_info = NULL;
 827	kfree(cinfo);
 828	return ret;
 829}
 830
 
 
 
 
 
 
 
 
 
 
 
 
 
 831static void resync_bitmap(struct mddev *mddev)
 832{
 833	struct md_cluster_info *cinfo = mddev->cluster_info;
 834	struct cluster_msg cmsg = {0};
 835	int err;
 836
 837	cmsg.type = cpu_to_le32(BITMAP_NEEDS_SYNC);
 838	err = sendmsg(cinfo, &cmsg);
 839	if (err)
 840		pr_err("%s:%d: failed to send BITMAP_NEEDS_SYNC message (%d)\n",
 841			__func__, __LINE__, err);
 842}
 843
 844static void unlock_all_bitmaps(struct mddev *mddev);
 845static int leave(struct mddev *mddev)
 846{
 847	struct md_cluster_info *cinfo = mddev->cluster_info;
 848
 849	if (!cinfo)
 850		return 0;
 851
 852	/* BITMAP_NEEDS_SYNC message should be sent when node
 
 853	 * is leaving the cluster with dirty bitmap, also we
 854	 * can only deliver it when dlm connection is available */
 855	if (cinfo->slot_number > 0 && mddev->recovery_cp != MaxSector)
 
 
 
 
 
 
 856		resync_bitmap(mddev);
 857
 858	md_unregister_thread(&cinfo->recovery_thread);
 859	md_unregister_thread(&cinfo->recv_thread);
 
 860	lockres_free(cinfo->message_lockres);
 861	lockres_free(cinfo->token_lockres);
 862	lockres_free(cinfo->ack_lockres);
 863	lockres_free(cinfo->no_new_dev_lockres);
 864	lockres_free(cinfo->resync_lockres);
 865	lockres_free(cinfo->bitmap_lockres);
 866	unlock_all_bitmaps(mddev);
 867	dlm_release_lockspace(cinfo->lockspace, 2);
 
 868	return 0;
 869}
 870
 871/* slot_number(): Returns the MD slot number to use
 872 * DLM starts the slot numbers from 1, wheras cluster-md
 873 * wants the number to be from zero, so we deduct one
 874 */
 875static int slot_number(struct mddev *mddev)
 876{
 877	struct md_cluster_info *cinfo = mddev->cluster_info;
 878
 879	return cinfo->slot_number - 1;
 880}
 881
 882/*
 883 * Check if the communication is already locked, else lock the communication
 884 * channel.
 885 * If it is already locked, token is in EX mode, and hence lock_token()
 886 * should not be called.
 887 */
 888static int metadata_update_start(struct mddev *mddev)
 889{
 890	struct md_cluster_info *cinfo = mddev->cluster_info;
 
 
 
 
 
 
 
 
 
 
 891
 892	wait_event(cinfo->wait,
 893		   !test_and_set_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state) ||
 894		   test_and_clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state));
 895
 896	/* If token is already locked, return 0 */
 897	if (cinfo->token_lockres->mode == DLM_LOCK_EX)
 
 898		return 0;
 
 899
 900	return lock_token(cinfo);
 
 
 901}
 902
 903static int metadata_update_finish(struct mddev *mddev)
 904{
 905	struct md_cluster_info *cinfo = mddev->cluster_info;
 906	struct cluster_msg cmsg;
 907	struct md_rdev *rdev;
 908	int ret = 0;
 909	int raid_slot = -1;
 910
 911	memset(&cmsg, 0, sizeof(cmsg));
 912	cmsg.type = cpu_to_le32(METADATA_UPDATED);
 913	/* Pick up a good active device number to send.
 914	 */
 915	rdev_for_each(rdev, mddev)
 916		if (rdev->raid_disk > -1 && !test_bit(Faulty, &rdev->flags)) {
 917			raid_slot = rdev->desc_nr;
 918			break;
 919		}
 920	if (raid_slot >= 0) {
 921		cmsg.raid_slot = cpu_to_le32(raid_slot);
 922		ret = __sendmsg(cinfo, &cmsg);
 923	} else
 924		pr_warn("md-cluster: No good device id found to send\n");
 925	clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
 926	unlock_comm(cinfo);
 927	return ret;
 928}
 929
 930static void metadata_update_cancel(struct mddev *mddev)
 931{
 932	struct md_cluster_info *cinfo = mddev->cluster_info;
 933	clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
 934	unlock_comm(cinfo);
 935}
 936
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 937static int resync_start(struct mddev *mddev)
 938{
 939	struct md_cluster_info *cinfo = mddev->cluster_info;
 940	cinfo->resync_lockres->flags |= DLM_LKF_NOQUEUE;
 941	return dlm_lock_sync(cinfo->resync_lockres, DLM_LOCK_EX);
 
 
 
 
 
 
 
 
 
 942}
 943
 944static int resync_info_update(struct mddev *mddev, sector_t lo, sector_t hi)
 945{
 946	struct md_cluster_info *cinfo = mddev->cluster_info;
 947	struct resync_info ri;
 948	struct cluster_msg cmsg = {0};
 949
 950	/* do not send zero again, if we have sent before */
 951	if (hi == 0) {
 952		memcpy(&ri, cinfo->bitmap_lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
 953		if (le64_to_cpu(ri.hi) == 0)
 954			return 0;
 955	}
 956
 957	add_resync_info(cinfo->bitmap_lockres, lo, hi);
 958	/* Re-acquire the lock to refresh LVB */
 959	dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW);
 960	cmsg.type = cpu_to_le32(RESYNCING);
 961	cmsg.low = cpu_to_le64(lo);
 962	cmsg.high = cpu_to_le64(hi);
 963
 964	return sendmsg(cinfo, &cmsg);
 
 
 
 
 
 
 
 965}
 966
 967static int resync_finish(struct mddev *mddev)
 968{
 969	struct md_cluster_info *cinfo = mddev->cluster_info;
 970	cinfo->resync_lockres->flags &= ~DLM_LKF_NOQUEUE;
 
 
 
 
 
 
 
 
 
 971	dlm_unlock_sync(cinfo->resync_lockres);
 972	return resync_info_update(mddev, 0, 0);
 973}
 974
 975static int area_resyncing(struct mddev *mddev, int direction,
 976		sector_t lo, sector_t hi)
 977{
 978	struct md_cluster_info *cinfo = mddev->cluster_info;
 979	int ret = 0;
 980	struct suspend_info *s;
 981
 982	if ((direction == READ) &&
 983		test_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state))
 984		return 1;
 985
 986	spin_lock_irq(&cinfo->suspend_lock);
 987	if (list_empty(&cinfo->suspend_list))
 988		goto out;
 989	list_for_each_entry(s, &cinfo->suspend_list, list)
 990		if (hi > s->lo && lo < s->hi) {
 991			ret = 1;
 992			break;
 993		}
 994out:
 995	spin_unlock_irq(&cinfo->suspend_lock);
 996	return ret;
 997}
 998
 999/* add_new_disk() - initiates a disk add
1000 * However, if this fails before writing md_update_sb(),
1001 * add_new_disk_cancel() must be called to release token lock
1002 */
1003static int add_new_disk(struct mddev *mddev, struct md_rdev *rdev)
1004{
1005	struct md_cluster_info *cinfo = mddev->cluster_info;
1006	struct cluster_msg cmsg;
1007	int ret = 0;
1008	struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1009	char *uuid = sb->device_uuid;
1010
1011	memset(&cmsg, 0, sizeof(cmsg));
1012	cmsg.type = cpu_to_le32(NEWDISK);
1013	memcpy(cmsg.uuid, uuid, 16);
1014	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1015	lock_comm(cinfo);
 
1016	ret = __sendmsg(cinfo, &cmsg);
1017	if (ret)
 
1018		return ret;
 
1019	cinfo->no_new_dev_lockres->flags |= DLM_LKF_NOQUEUE;
1020	ret = dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_EX);
1021	cinfo->no_new_dev_lockres->flags &= ~DLM_LKF_NOQUEUE;
1022	/* Some node does not "see" the device */
1023	if (ret == -EAGAIN)
1024		ret = -ENOENT;
1025	if (ret)
1026		unlock_comm(cinfo);
1027	else {
1028		dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
1029		/* Since MD_CHANGE_DEVS will be set in add_bound_rdev which
1030		 * will run soon after add_new_disk, the below path will be
1031		 * invoked:
1032		 *   md_wakeup_thread(mddev->thread)
1033		 *	-> conf->thread (raid1d)
1034		 *	-> md_check_recovery -> md_update_sb
1035		 *	-> metadata_update_start/finish
1036		 * MD_CLUSTER_SEND_LOCKED_ALREADY will be cleared eventually.
1037		 *
1038		 * For other failure cases, metadata_update_cancel and
1039		 * add_new_disk_cancel also clear below bit as well.
1040		 * */
1041		set_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1042		wake_up(&cinfo->wait);
1043	}
1044	return ret;
1045}
1046
1047static void add_new_disk_cancel(struct mddev *mddev)
1048{
1049	struct md_cluster_info *cinfo = mddev->cluster_info;
1050	clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1051	unlock_comm(cinfo);
1052}
1053
1054static int new_disk_ack(struct mddev *mddev, bool ack)
1055{
1056	struct md_cluster_info *cinfo = mddev->cluster_info;
1057
1058	if (!test_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state)) {
1059		pr_warn("md-cluster(%s): Spurious cluster confirmation\n", mdname(mddev));
1060		return -EINVAL;
1061	}
1062
1063	if (ack)
1064		dlm_unlock_sync(cinfo->no_new_dev_lockres);
1065	complete(&cinfo->newdisk_completion);
1066	return 0;
1067}
1068
1069static int remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1070{
1071	struct cluster_msg cmsg = {0};
1072	struct md_cluster_info *cinfo = mddev->cluster_info;
1073	cmsg.type = cpu_to_le32(REMOVE);
1074	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1075	return sendmsg(cinfo, &cmsg);
1076}
1077
1078static int lock_all_bitmaps(struct mddev *mddev)
1079{
1080	int slot, my_slot, ret, held = 1, i = 0;
1081	char str[64];
1082	struct md_cluster_info *cinfo = mddev->cluster_info;
1083
1084	cinfo->other_bitmap_lockres = kzalloc((mddev->bitmap_info.nodes - 1) *
1085					     sizeof(struct dlm_lock_resource *),
1086					     GFP_KERNEL);
1087	if (!cinfo->other_bitmap_lockres) {
1088		pr_err("md: can't alloc mem for other bitmap locks\n");
1089		return 0;
1090	}
1091
1092	my_slot = slot_number(mddev);
1093	for (slot = 0; slot < mddev->bitmap_info.nodes; slot++) {
1094		if (slot == my_slot)
1095			continue;
1096
1097		memset(str, '\0', 64);
1098		snprintf(str, 64, "bitmap%04d", slot);
1099		cinfo->other_bitmap_lockres[i] = lockres_init(mddev, str, NULL, 1);
1100		if (!cinfo->other_bitmap_lockres[i])
1101			return -ENOMEM;
1102
1103		cinfo->other_bitmap_lockres[i]->flags |= DLM_LKF_NOQUEUE;
1104		ret = dlm_lock_sync(cinfo->other_bitmap_lockres[i], DLM_LOCK_PW);
1105		if (ret)
1106			held = -1;
1107		i++;
1108	}
1109
1110	return held;
1111}
1112
1113static void unlock_all_bitmaps(struct mddev *mddev)
1114{
1115	struct md_cluster_info *cinfo = mddev->cluster_info;
1116	int i;
1117
1118	/* release other node's bitmap lock if they are existed */
1119	if (cinfo->other_bitmap_lockres) {
1120		for (i = 0; i < mddev->bitmap_info.nodes - 1; i++) {
1121			if (cinfo->other_bitmap_lockres[i]) {
1122				dlm_unlock_sync(cinfo->other_bitmap_lockres[i]);
1123				lockres_free(cinfo->other_bitmap_lockres[i]);
1124			}
1125		}
1126		kfree(cinfo->other_bitmap_lockres);
 
1127	}
1128}
1129
1130static int gather_bitmaps(struct md_rdev *rdev)
1131{
1132	int sn, err;
1133	sector_t lo, hi;
1134	struct cluster_msg cmsg = {0};
1135	struct mddev *mddev = rdev->mddev;
1136	struct md_cluster_info *cinfo = mddev->cluster_info;
1137
1138	cmsg.type = cpu_to_le32(RE_ADD);
1139	cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1140	err = sendmsg(cinfo, &cmsg);
1141	if (err)
1142		goto out;
1143
1144	for (sn = 0; sn < mddev->bitmap_info.nodes; sn++) {
1145		if (sn == (cinfo->slot_number - 1))
1146			continue;
1147		err = bitmap_copy_from_slot(mddev, sn, &lo, &hi, false);
1148		if (err) {
1149			pr_warn("md-cluster: Could not gather bitmaps from slot %d", sn);
1150			goto out;
1151		}
1152		if ((hi > 0) && (lo < mddev->recovery_cp))
1153			mddev->recovery_cp = lo;
1154	}
1155out:
1156	return err;
1157}
1158
1159static struct md_cluster_operations cluster_ops = {
1160	.join   = join,
1161	.leave  = leave,
1162	.slot_number = slot_number,
1163	.resync_start = resync_start,
1164	.resync_finish = resync_finish,
1165	.resync_info_update = resync_info_update,
 
1166	.metadata_update_start = metadata_update_start,
1167	.metadata_update_finish = metadata_update_finish,
1168	.metadata_update_cancel = metadata_update_cancel,
1169	.area_resyncing = area_resyncing,
1170	.add_new_disk = add_new_disk,
1171	.add_new_disk_cancel = add_new_disk_cancel,
1172	.new_disk_ack = new_disk_ack,
1173	.remove_disk = remove_disk,
 
1174	.gather_bitmaps = gather_bitmaps,
 
1175	.lock_all_bitmaps = lock_all_bitmaps,
1176	.unlock_all_bitmaps = unlock_all_bitmaps,
 
1177};
1178
1179static int __init cluster_init(void)
1180{
1181	pr_warn("md-cluster: EXPERIMENTAL. Use with caution\n");
1182	pr_info("Registering Cluster MD functions\n");
1183	register_md_cluster_operations(&cluster_ops, THIS_MODULE);
1184	return 0;
1185}
1186
1187static void cluster_exit(void)
1188{
1189	unregister_md_cluster_operations();
1190}
1191
1192module_init(cluster_init);
1193module_exit(cluster_exit);
1194MODULE_AUTHOR("SUSE");
1195MODULE_LICENSE("GPL");
1196MODULE_DESCRIPTION("Clustering support for MD");