drivers/md/md-cluster.c

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