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 "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 suspend_info {
  37         int slot;
  38         sector_t lo;
  39         sector_t hi;
  40         struct list_head list;
  41 };
  42
  43 struct resync_info {
  44         __le64 lo;
  45         __le64 hi;
  46 };
  47
  48 /* md_cluster_info flags */
  49 #define         MD_CLUSTER_WAITING_FOR_NEWDISK          1
  50 #define         MD_CLUSTER_SUSPEND_READ_BALANCING       2
  51 #define         MD_CLUSTER_BEGIN_JOIN_CLUSTER           3
  52
  53 /* Lock the send communication. This is done through
  54  * bit manipulation as opposed to a mutex in order to
  55  * accomodate lock and hold. See next comment.
  56  */
  57 #define         MD_CLUSTER_SEND_LOCK                    4
  58 /* If cluster operations (such as adding a disk) must lock the
  59  * communication channel, so as to perform extra operations
  60  * (update metadata) and no other operation is allowed on the
  61  * MD. Token needs to be locked and held until the operation
  62  * completes witha md_update_sb(), which would eventually release
  63  * the lock.
  64  */
  65 #define         MD_CLUSTER_SEND_LOCKED_ALREADY          5
  66 /* We should receive message after node joined cluster and
  67  * set up all the related infos such as bitmap and personality */
  68 #define         MD_CLUSTER_ALREADY_IN_CLUSTER           6
  69 #define         MD_CLUSTER_PENDING_RECV_EVENT           7
  70 #define         MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD              8
  71
  72 struct md_cluster_info {
  73         struct mddev *mddev; /* the md device which md_cluster_info belongs to */
  74         /* dlm lock space and resources for clustered raid. */
  75         dlm_lockspace_t *lockspace;
  76         int slot_number;
  77         struct completion completion;
  78         struct mutex recv_mutex;
  79         struct dlm_lock_resource *bitmap_lockres;
  80         struct dlm_lock_resource **other_bitmap_lockres;
  81         struct dlm_lock_resource *resync_lockres;
  82         struct list_head suspend_list;
  83         spinlock_t suspend_lock;
  84         struct md_thread *recovery_thread;
  85         unsigned long recovery_map;
  86         /* communication loc resources */
  87         struct dlm_lock_resource *ack_lockres;
  88         struct dlm_lock_resource *message_lockres;
  89         struct dlm_lock_resource *token_lockres;
  90         struct dlm_lock_resource *no_new_dev_lockres;
  91         struct md_thread *recv_thread;
  92         struct completion newdisk_completion;
  93         wait_queue_head_t wait;
  94         unsigned long state;
  95         /* record the region in RESYNCING message */
  96         sector_t sync_low;
  97         sector_t sync_hi;
  98 };
  99
 100 enum msg_type {
 101         METADATA_UPDATED = 0,
 102         RESYNCING,
 103         NEWDISK,
 104         REMOVE,
 105         RE_ADD,
 106         BITMAP_NEEDS_SYNC,
 107         CHANGE_CAPACITY,
 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 struct suspend_info *read_resync_info(struct mddev *mddev, struct dlm_lock_resource *lockres)
 274 {
 275         struct resync_info ri;
 276         struct suspend_info *s = NULL;
 277         sector_t hi = 0;
 278
 279         dlm_lock_sync(lockres, DLM_LOCK_CR);
 280         memcpy(&ri, lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
 281         hi = le64_to_cpu(ri.hi);
 282         if (hi > 0) {
 283                 s = kzalloc(sizeof(struct suspend_info), GFP_KERNEL);
 284                 if (!s)
 285                         goto out;
 286                 s->hi = hi;
 287                 s->lo = le64_to_cpu(ri.lo);
 288         }
 289         dlm_unlock_sync(lockres);
 290 out:
 291         return s;
 292 }
 293
 294 static void recover_bitmaps(struct md_thread *thread)
 295 {
 296         struct mddev *mddev = thread->mddev;
 297         struct md_cluster_info *cinfo = mddev->cluster_info;
 298         struct dlm_lock_resource *bm_lockres;
 299         char str[64];
 300         int slot, ret;
 301         struct suspend_info *s, *tmp;
 302         sector_t lo, hi;
 303
 304         while (cinfo->recovery_map) {
 305                 slot = fls64((u64)cinfo->recovery_map) - 1;
 306
 307                 snprintf(str, 64, "bitmap%04d", slot);
 308                 bm_lockres = lockres_init(mddev, str, NULL, 1);
 309                 if (!bm_lockres) {
 310                         pr_err("md-cluster: Cannot initialize bitmaps\n");
 311                         goto clear_bit;
 312                 }
 313
 314                 ret = dlm_lock_sync_interruptible(bm_lockres, DLM_LOCK_PW, mddev);
 315                 if (ret) {
 316                         pr_err("md-cluster: Could not DLM lock %s: %d\n",
 317                                         str, ret);
 318                         goto clear_bit;
 319                 }
 320                 ret = bitmap_copy_from_slot(mddev, slot, &lo, &hi, true);
 321                 if (ret) {
 322                         pr_err("md-cluster: Could not copy data from bitmap %d\n", slot);
 323                         goto clear_bit;
 324                 }
 325
 326                 /* Clear suspend_area associated with the bitmap */
 327                 spin_lock_irq(&cinfo->suspend_lock);
 328                 list_for_each_entry_safe(s, tmp, &cinfo->suspend_list, list)
 329                         if (slot == s->slot) {
 330                                 list_del(&s->list);
 331                                 kfree(s);
 332                         }
 333                 spin_unlock_irq(&cinfo->suspend_lock);
 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                             set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 342                             md_wakeup_thread(mddev->thread);
 343                         }
 344                 }
 345 clear_bit:
 346                 lockres_free(bm_lockres);
 347                 clear_bit(slot, &cinfo->recovery_map);
 348         }
 349 }
 350
 351 static void recover_prep(void *arg)
 352 {
 353         struct mddev *mddev = arg;
 354         struct md_cluster_info *cinfo = mddev->cluster_info;
 355         set_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state);
 356 }
 357
 358 static void __recover_slot(struct mddev *mddev, int slot)
 359 {
 360         struct md_cluster_info *cinfo = mddev->cluster_info;
 361
 362         set_bit(slot, &cinfo->recovery_map);
 363         if (!cinfo->recovery_thread) {
 364                 cinfo->recovery_thread = md_register_thread(recover_bitmaps,
 365                                 mddev, "recover");
 366                 if (!cinfo->recovery_thread) {
 367                         pr_warn("md-cluster: Could not create recovery thread\n");
 368                         return;
 369                 }
 370         }
 371         md_wakeup_thread(cinfo->recovery_thread);
 372 }
 373
 374 static void recover_slot(void *arg, struct dlm_slot *slot)
 375 {
 376         struct mddev *mddev = arg;
 377         struct md_cluster_info *cinfo = mddev->cluster_info;
 378
 379         pr_info("md-cluster: %s Node %d/%d down. My slot: %d. Initiating recovery.\n",
 380                         mddev->bitmap_info.cluster_name,
 381                         slot->nodeid, slot->slot,
 382                         cinfo->slot_number);
 383         /* deduct one since dlm slot starts from one while the num of
 384          * cluster-md begins with 0 */
 385         __recover_slot(mddev, slot->slot - 1);
 386 }
 387
 388 static void recover_done(void *arg, struct dlm_slot *slots,
 389                 int num_slots, int our_slot,
 390                 uint32_t generation)
 391 {
 392         struct mddev *mddev = arg;
 393         struct md_cluster_info *cinfo = mddev->cluster_info;
 394
 395         cinfo->slot_number = our_slot;
 396         /* completion is only need to be complete when node join cluster,
 397          * it doesn't need to run during another node's failure */
 398         if (test_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state)) {
 399                 complete(&cinfo->completion);
 400                 clear_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state);
 401         }
 402         clear_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state);
 403 }
 404
 405 /* the ops is called when node join the cluster, and do lock recovery
 406  * if node failure occurs */
 407 static const struct dlm_lockspace_ops md_ls_ops = {
 408         .recover_prep = recover_prep,
 409         .recover_slot = recover_slot,
 410         .recover_done = recover_done,
 411 };
 412
 413 /*
 414  * The BAST function for the ack lock resource
 415  * This function wakes up the receive thread in
 416  * order to receive and process the message.
 417  */
 418 static void ack_bast(void *arg, int mode)
 419 {
 420         struct dlm_lock_resource *res = arg;
 421         struct md_cluster_info *cinfo = res->mddev->cluster_info;
 422
 423         if (mode == DLM_LOCK_EX) {
 424                 if (test_bit(MD_CLUSTER_ALREADY_IN_CLUSTER, &cinfo->state))
 425                         md_wakeup_thread(cinfo->recv_thread);
 426                 else
 427                         set_bit(MD_CLUSTER_PENDING_RECV_EVENT, &cinfo->state);
 428         }
 429 }
 430
 431 static void __remove_suspend_info(struct md_cluster_info *cinfo, int slot)
 432 {
 433         struct suspend_info *s, *tmp;
 434
 435         list_for_each_entry_safe(s, tmp, &cinfo->suspend_list, list)
 436                 if (slot == s->slot) {
 437                         list_del(&s->list);
 438                         kfree(s);
 439                         break;
 440                 }
 441 }
 442
 443 static void remove_suspend_info(struct mddev *mddev, int slot)
 444 {
 445         struct md_cluster_info *cinfo = mddev->cluster_info;
 446         mddev->pers->quiesce(mddev, 1);
 447         spin_lock_irq(&cinfo->suspend_lock);
 448         __remove_suspend_info(cinfo, slot);
 449         spin_unlock_irq(&cinfo->suspend_lock);
 450         mddev->pers->quiesce(mddev, 0);
 451 }
 452
 453
 454 static void process_suspend_info(struct mddev *mddev,
 455                 int slot, sector_t lo, sector_t hi)
 456 {
 457         struct md_cluster_info *cinfo = mddev->cluster_info;
 458         struct suspend_info *s;
 459
 460         if (!hi) {
 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         /*
 468          * The bitmaps are not same for different nodes
 469          * if RESYNCING is happening in one node, then
 470          * the node which received the RESYNCING message
 471          * probably will perform resync with the region
 472          * [lo, hi] again, so we could reduce resync time
 473          * a lot if we can ensure that the bitmaps among
 474          * different nodes are match up well.
 475          *
 476          * sync_low/hi is used to record the region which
 477          * arrived in the previous RESYNCING message,
 478          *
 479          * Call bitmap_sync_with_cluster to clear
 480          * NEEDED_MASK and set RESYNC_MASK since
 481          * resync thread is running in another node,
 482          * so we don't need to do the resync again
 483          * with the same section */
 484         bitmap_sync_with_cluster(mddev, cinfo->sync_low,
 485                                         cinfo->sync_hi,
 486                                         lo, hi);
 487         cinfo->sync_low = lo;
 488         cinfo->sync_hi = hi;
 489
 490         s = kzalloc(sizeof(struct suspend_info), GFP_KERNEL);
 491         if (!s)
 492                 return;
 493         s->slot = slot;
 494         s->lo = lo;
 495         s->hi = hi;
 496         mddev->pers->quiesce(mddev, 1);
 497         spin_lock_irq(&cinfo->suspend_lock);
 498         /* Remove existing entry (if exists) before adding */
 499         __remove_suspend_info(cinfo, slot);
 500         list_add(&s->list, &cinfo->suspend_list);
 501         spin_unlock_irq(&cinfo->suspend_lock);
 502         mddev->pers->quiesce(mddev, 0);
 503 }
 504
 505 static void process_add_new_disk(struct mddev *mddev, struct cluster_msg *cmsg)
 506 {
 507         char disk_uuid[64];
 508         struct md_cluster_info *cinfo = mddev->cluster_info;
 509         char event_name[] = "EVENT=ADD_DEVICE";
 510         char raid_slot[16];
 511         char *envp[] = {event_name, disk_uuid, raid_slot, NULL};
 512         int len;
 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         wait_for_completion_timeout(&cinfo->newdisk_completion,
 522                         NEW_DEV_TIMEOUT);
 523         clear_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state);
 524 }
 525
 526
 527 static void process_metadata_update(struct mddev *mddev, struct cluster_msg *msg)
 528 {
 529         int got_lock = 0;
 530         struct md_cluster_info *cinfo = mddev->cluster_info;
 531         mddev->good_device_nr = le32_to_cpu(msg->raid_slot);
 532
 533         dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
 534         wait_event(mddev->thread->wqueue,
 535                    (got_lock = mddev_trylock(mddev)) ||
 536                     test_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state));
 537         md_reload_sb(mddev, mddev->good_device_nr);
 538         if (got_lock)
 539                 mddev_unlock(mddev);
 540 }
 541
 542 static void process_remove_disk(struct mddev *mddev, struct cluster_msg *msg)
 543 {
 544         struct md_rdev *rdev;
 545
 546         rcu_read_lock();
 547         rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));
 548         if (rdev) {
 549                 set_bit(ClusterRemove, &rdev->flags);
 550                 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 551                 md_wakeup_thread(mddev->thread);
 552         }
 553         else
 554                 pr_warn("%s: %d Could not find disk(%d) to REMOVE\n",
 555                         __func__, __LINE__, le32_to_cpu(msg->raid_slot));
 556         rcu_read_unlock();
 557 }
 558
 559 static void process_readd_disk(struct mddev *mddev, struct cluster_msg *msg)
 560 {
 561         struct md_rdev *rdev;
 562
 563         rcu_read_lock();
 564         rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));
 565         if (rdev && test_bit(Faulty, &rdev->flags))
 566                 clear_bit(Faulty, &rdev->flags);
 567         else
 568                 pr_warn("%s: %d Could not find disk(%d) which is faulty",
 569                         __func__, __LINE__, le32_to_cpu(msg->raid_slot));
 570         rcu_read_unlock();
 571 }
 572
 573 static int process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
 574 {
 575         int ret = 0;
 576
 577         if (WARN(mddev->cluster_info->slot_number - 1 == le32_to_cpu(msg->slot),
 578                 "node %d received it's own msg\n", le32_to_cpu(msg->slot)))
 579                 return -1;
 580         switch (le32_to_cpu(msg->type)) {
 581         case METADATA_UPDATED:
 582                 process_metadata_update(mddev, msg);
 583                 break;
 584         case CHANGE_CAPACITY:
 585                 set_capacity(mddev->gendisk, mddev->array_sectors);
 586                 revalidate_disk(mddev->gendisk);
 587                 break;
 588         case RESYNCING:
 589                 process_suspend_info(mddev, le32_to_cpu(msg->slot),
 590                                      le64_to_cpu(msg->low),
 591                                      le64_to_cpu(msg->high));
 592                 break;
 593         case NEWDISK:
 594                 process_add_new_disk(mddev, msg);
 595                 break;
 596         case REMOVE:
 597                 process_remove_disk(mddev, msg);
 598                 break;
 599         case RE_ADD:
 600                 process_readd_disk(mddev, msg);
 601                 break;
 602         case BITMAP_NEEDS_SYNC:
 603                 __recover_slot(mddev, le32_to_cpu(msg->slot));
 604                 break;
 605         default:
 606                 ret = -1;
 607                 pr_warn("%s:%d Received unknown message from %d\n",
 608                         __func__, __LINE__, msg->slot);
 609         }
 610         return ret;
 611 }
 612
 613 /*
 614  * thread for receiving message
 615  */
 616 static void recv_daemon(struct md_thread *thread)
 617 {
 618         struct md_cluster_info *cinfo = thread->mddev->cluster_info;
 619         struct dlm_lock_resource *ack_lockres = cinfo->ack_lockres;
 620         struct dlm_lock_resource *message_lockres = cinfo->message_lockres;
 621         struct cluster_msg msg;
 622         int ret;
 623
 624         mutex_lock(&cinfo->recv_mutex);
 625         /*get CR on Message*/
 626         if (dlm_lock_sync(message_lockres, DLM_LOCK_CR)) {
 627                 pr_err("md/raid1:failed to get CR on MESSAGE\n");
 628                 mutex_unlock(&cinfo->recv_mutex);
 629                 return;
 630         }
 631
 632         /* read lvb and wake up thread to process this message_lockres */
 633         memcpy(&msg, message_lockres->lksb.sb_lvbptr, sizeof(struct cluster_msg));
 634         ret = process_recvd_msg(thread->mddev, &msg);
 635         if (ret)
 636                 goto out;
 637
 638         /*release CR on ack_lockres*/
 639         ret = dlm_unlock_sync(ack_lockres);
 640         if (unlikely(ret != 0))
 641                 pr_info("unlock ack failed return %d\n", ret);
 642         /*up-convert to PR on message_lockres*/
 643         ret = dlm_lock_sync(message_lockres, DLM_LOCK_PR);
 644         if (unlikely(ret != 0))
 645                 pr_info("lock PR on msg failed return %d\n", ret);
 646         /*get CR on ack_lockres again*/
 647         ret = dlm_lock_sync(ack_lockres, DLM_LOCK_CR);
 648         if (unlikely(ret != 0))
 649                 pr_info("lock CR on ack failed return %d\n", ret);
 650 out:
 651         /*release CR on message_lockres*/
 652         ret = dlm_unlock_sync(message_lockres);
 653         if (unlikely(ret != 0))
 654                 pr_info("unlock msg failed return %d\n", ret);
 655         mutex_unlock(&cinfo->recv_mutex);
 656 }
 657
 658 /* lock_token()
 659  * Takes the lock on the TOKEN lock resource so no other
 660  * node can communicate while the operation is underway.
 661  */
 662 static int lock_token(struct md_cluster_info *cinfo)
 663 {
 664         int error;
 665
 666         error = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
 667         if (error) {
 668                 pr_err("md-cluster(%s:%d): failed to get EX on TOKEN (%d)\n",
 669                                 __func__, __LINE__, error);
 670         } else {
 671                 /* Lock the receive sequence */
 672                 mutex_lock(&cinfo->recv_mutex);
 673         }
 674         return error;
 675 }
 676
 677 /* lock_comm()
 678  * Sets the MD_CLUSTER_SEND_LOCK bit to lock the send channel.
 679  */
 680 static int lock_comm(struct md_cluster_info *cinfo, bool mddev_locked)
 681 {
 682         int rv, set_bit = 0;
 683         struct mddev *mddev = cinfo->mddev;
 684
 685         /*
 686          * If resync thread run after raid1d thread, then process_metadata_update
 687          * could not continue if raid1d held reconfig_mutex (and raid1d is blocked
 688          * since another node already got EX on Token and waitting the EX of Ack),
 689          * so let resync wake up thread in case flag is set.
 690          */
 691         if (mddev_locked && !test_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
 692                                       &cinfo->state)) {
 693                 rv = test_and_set_bit_lock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
 694                                               &cinfo->state);
 695                 WARN_ON_ONCE(rv);
 696                 md_wakeup_thread(mddev->thread);
 697                 set_bit = 1;
 698         }
 699
 700         wait_event(cinfo->wait,
 701                    !test_and_set_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state));
 702         rv = lock_token(cinfo);
 703         if (set_bit)
 704                 clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
 705         return rv;
 706 }
 707
 708 static void unlock_comm(struct md_cluster_info *cinfo)
 709 {
 710         WARN_ON(cinfo->token_lockres->mode != DLM_LOCK_EX);
 711         mutex_unlock(&cinfo->recv_mutex);
 712         dlm_unlock_sync(cinfo->token_lockres);
 713         clear_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state);
 714         wake_up(&cinfo->wait);
 715 }
 716
 717 /* __sendmsg()
 718  * This function performs the actual sending of the message. This function is
 719  * usually called after performing the encompassing operation
 720  * The function:
 721  * 1. Grabs the message lockresource in EX mode
 722  * 2. Copies the message to the message LVB
 723  * 3. Downconverts message lockresource to CW
 724  * 4. Upconverts ack lock resource from CR to EX. This forces the BAST on other nodes
 725  *    and the other nodes read the message. The thread will wait here until all other
 726  *    nodes have released ack lock resource.
 727  * 5. Downconvert ack lockresource to CR
 728  */
 729 static int __sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg)
 730 {
 731         int error;
 732         int slot = cinfo->slot_number - 1;
 733
 734         cmsg->slot = cpu_to_le32(slot);
 735         /*get EX on Message*/
 736         error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_EX);
 737         if (error) {
 738                 pr_err("md-cluster: failed to get EX on MESSAGE (%d)\n", error);
 739                 goto failed_message;
 740         }
 741
 742         memcpy(cinfo->message_lockres->lksb.sb_lvbptr, (void *)cmsg,
 743                         sizeof(struct cluster_msg));
 744         /*down-convert EX to CW on Message*/
 745         error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_CW);
 746         if (error) {
 747                 pr_err("md-cluster: failed to convert EX to CW on MESSAGE(%d)\n",
 748                                 error);
 749                 goto failed_ack;
 750         }
 751
 752         /*up-convert CR to EX on Ack*/
 753         error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_EX);
 754         if (error) {
 755                 pr_err("md-cluster: failed to convert CR to EX on ACK(%d)\n",
 756                                 error);
 757                 goto failed_ack;
 758         }
 759
 760         /*down-convert EX to CR on Ack*/
 761         error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR);
 762         if (error) {
 763                 pr_err("md-cluster: failed to convert EX to CR on ACK(%d)\n",
 764                                 error);
 765                 goto failed_ack;
 766         }
 767
 768 failed_ack:
 769         error = dlm_unlock_sync(cinfo->message_lockres);
 770         if (unlikely(error != 0)) {
 771                 pr_err("md-cluster: failed convert to NL on MESSAGE(%d)\n",
 772                         error);
 773                 /* in case the message can't be released due to some reason */
 774                 goto failed_ack;
 775         }
 776 failed_message:
 777         return error;
 778 }
 779
 780 static int sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg,
 781                    bool mddev_locked)
 782 {
 783         int ret;
 784
 785         ret = lock_comm(cinfo, mddev_locked);
 786         if (!ret) {
 787                 ret = __sendmsg(cinfo, cmsg);
 788                 unlock_comm(cinfo);
 789         }
 790         return ret;
 791 }
 792
 793 static int gather_all_resync_info(struct mddev *mddev, int total_slots)
 794 {
 795         struct md_cluster_info *cinfo = mddev->cluster_info;
 796         int i, ret = 0;
 797         struct dlm_lock_resource *bm_lockres;
 798         struct suspend_info *s;
 799         char str[64];
 800         sector_t lo, hi;
 801
 802
 803         for (i = 0; i < total_slots; i++) {
 804                 memset(str, '\0', 64);
 805                 snprintf(str, 64, "bitmap%04d", i);
 806                 bm_lockres = lockres_init(mddev, str, NULL, 1);
 807                 if (!bm_lockres)
 808                         return -ENOMEM;
 809                 if (i == (cinfo->slot_number - 1)) {
 810                         lockres_free(bm_lockres);
 811                         continue;
 812                 }
 813
 814                 bm_lockres->flags |= DLM_LKF_NOQUEUE;
 815                 ret = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
 816                 if (ret == -EAGAIN) {
 817                         s = read_resync_info(mddev, bm_lockres);
 818                         if (s) {
 819                                 pr_info("%s:%d Resync[%llu..%llu] in progress on %d\n",
 820                                                 __func__, __LINE__,
 821                                                 (unsigned long long) s->lo,
 822                                                 (unsigned long long) s->hi, i);
 823                                 spin_lock_irq(&cinfo->suspend_lock);
 824                                 s->slot = i;
 825                                 list_add(&s->list, &cinfo->suspend_list);
 826                                 spin_unlock_irq(&cinfo->suspend_lock);
 827                         }
 828                         ret = 0;
 829                         lockres_free(bm_lockres);
 830                         continue;
 831                 }
 832                 if (ret) {
 833                         lockres_free(bm_lockres);
 834                         goto out;
 835                 }
 836
 837                 /* Read the disk bitmap sb and check if it needs recovery */
 838                 ret = bitmap_copy_from_slot(mddev, i, &lo, &hi, false);
 839                 if (ret) {
 840                         pr_warn("md-cluster: Could not gather bitmaps from slot %d", i);
 841                         lockres_free(bm_lockres);
 842                         continue;
 843                 }
 844                 if ((hi > 0) && (lo < mddev->recovery_cp)) {
 845                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 846                         mddev->recovery_cp = lo;
 847                         md_check_recovery(mddev);
 848                 }
 849
 850                 lockres_free(bm_lockres);
 851         }
 852 out:
 853         return ret;
 854 }
 855
 856 static int join(struct mddev *mddev, int nodes)
 857 {
 858         struct md_cluster_info *cinfo;
 859         int ret, ops_rv;
 860         char str[64];
 861
 862         cinfo = kzalloc(sizeof(struct md_cluster_info), GFP_KERNEL);
 863         if (!cinfo)
 864                 return -ENOMEM;
 865
 866         INIT_LIST_HEAD(&cinfo->suspend_list);
 867         spin_lock_init(&cinfo->suspend_lock);
 868         init_completion(&cinfo->completion);
 869         set_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state);
 870         init_waitqueue_head(&cinfo->wait);
 871         mutex_init(&cinfo->recv_mutex);
 872
 873         mddev->cluster_info = cinfo;
 874         cinfo->mddev = mddev;
 875
 876         memset(str, 0, 64);
 877         sprintf(str, "%pU", mddev->uuid);
 878         ret = dlm_new_lockspace(str, mddev->bitmap_info.cluster_name,
 879                                 DLM_LSFL_FS, LVB_SIZE,
 880                                 &md_ls_ops, mddev, &ops_rv, &cinfo->lockspace);
 881         if (ret)
 882                 goto err;
 883         wait_for_completion(&cinfo->completion);
 884         if (nodes < cinfo->slot_number) {
 885                 pr_err("md-cluster: Slot allotted(%d) is greater than available slots(%d).",
 886                         cinfo->slot_number, nodes);
 887                 ret = -ERANGE;
 888                 goto err;
 889         }
 890         /* Initiate the communication resources */
 891         ret = -ENOMEM;
 892         cinfo->recv_thread = md_register_thread(recv_daemon, mddev, "cluster_recv");
 893         if (!cinfo->recv_thread) {
 894                 pr_err("md-cluster: cannot allocate memory for recv_thread!\n");
 895                 goto err;
 896         }
 897         cinfo->message_lockres = lockres_init(mddev, "message", NULL, 1);
 898         if (!cinfo->message_lockres)
 899                 goto err;
 900         cinfo->token_lockres = lockres_init(mddev, "token", NULL, 0);
 901         if (!cinfo->token_lockres)
 902                 goto err;
 903         cinfo->no_new_dev_lockres = lockres_init(mddev, "no-new-dev", NULL, 0);
 904         if (!cinfo->no_new_dev_lockres)
 905                 goto err;
 906
 907         ret = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
 908         if (ret) {
 909                 ret = -EAGAIN;
 910                 pr_err("md-cluster: can't join cluster to avoid lock issue\n");
 911                 goto err;
 912         }
 913         cinfo->ack_lockres = lockres_init(mddev, "ack", ack_bast, 0);
 914         if (!cinfo->ack_lockres) {
 915                 ret = -ENOMEM;
 916                 goto err;
 917         }
 918         /* get sync CR lock on ACK. */
 919         if (dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR))
 920                 pr_err("md-cluster: failed to get a sync CR lock on ACK!(%d)\n",
 921                                 ret);
 922         dlm_unlock_sync(cinfo->token_lockres);
 923         /* get sync CR lock on no-new-dev. */
 924         if (dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR))
 925                 pr_err("md-cluster: failed to get a sync CR lock on no-new-dev!(%d)\n", ret);
 926
 927
 928         pr_info("md-cluster: Joined cluster %s slot %d\n", str, cinfo->slot_number);
 929         snprintf(str, 64, "bitmap%04d", cinfo->slot_number - 1);
 930         cinfo->bitmap_lockres = lockres_init(mddev, str, NULL, 1);
 931         if (!cinfo->bitmap_lockres) {
 932                 ret = -ENOMEM;
 933                 goto err;
 934         }
 935         if (dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW)) {
 936                 pr_err("Failed to get bitmap lock\n");
 937                 ret = -EINVAL;
 938                 goto err;
 939         }
 940
 941         cinfo->resync_lockres = lockres_init(mddev, "resync", NULL, 0);
 942         if (!cinfo->resync_lockres) {
 943                 ret = -ENOMEM;
 944                 goto err;
 945         }
 946
 947         return 0;
 948 err:
 949         set_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
 950         md_unregister_thread(&cinfo->recovery_thread);
 951         md_unregister_thread(&cinfo->recv_thread);
 952         lockres_free(cinfo->message_lockres);
 953         lockres_free(cinfo->token_lockres);
 954         lockres_free(cinfo->ack_lockres);
 955         lockres_free(cinfo->no_new_dev_lockres);
 956         lockres_free(cinfo->resync_lockres);
 957         lockres_free(cinfo->bitmap_lockres);
 958         if (cinfo->lockspace)
 959                 dlm_release_lockspace(cinfo->lockspace, 2);
 960         mddev->cluster_info = NULL;
 961         kfree(cinfo);
 962         return ret;
 963 }
 964
 965 static void load_bitmaps(struct mddev *mddev, int total_slots)
 966 {
 967         struct md_cluster_info *cinfo = mddev->cluster_info;
 968
 969         /* load all the node's bitmap info for resync */
 970         if (gather_all_resync_info(mddev, total_slots))
 971                 pr_err("md-cluster: failed to gather all resyn infos\n");
 972         set_bit(MD_CLUSTER_ALREADY_IN_CLUSTER, &cinfo->state);
 973         /* wake up recv thread in case something need to be handled */
 974         if (test_and_clear_bit(MD_CLUSTER_PENDING_RECV_EVENT, &cinfo->state))
 975                 md_wakeup_thread(cinfo->recv_thread);
 976 }
 977
 978 static void resync_bitmap(struct mddev *mddev)
 979 {
 980         struct md_cluster_info *cinfo = mddev->cluster_info;
 981         struct cluster_msg cmsg = {0};
 982         int err;
 983
 984         cmsg.type = cpu_to_le32(BITMAP_NEEDS_SYNC);
 985         err = sendmsg(cinfo, &cmsg, 1);
 986         if (err)
 987                 pr_err("%s:%d: failed to send BITMAP_NEEDS_SYNC message (%d)\n",
 988                         __func__, __LINE__, err);
 989 }
 990
 991 static void unlock_all_bitmaps(struct mddev *mddev);
 992 static int leave(struct mddev *mddev)
 993 {
 994         struct md_cluster_info *cinfo = mddev->cluster_info;
 995
 996         if (!cinfo)
 997                 return 0;
 998
 999         /* BITMAP_NEEDS_SYNC message should be sent when node
1000          * is leaving the cluster with dirty bitmap, also we
1001          * can only deliver it when dlm connection is available */
1002         if (cinfo->slot_number > 0 && mddev->recovery_cp != MaxSector)
1003                 resync_bitmap(mddev);
1004
1005         set_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
1006         md_unregister_thread(&cinfo->recovery_thread);
1007         md_unregister_thread(&cinfo->recv_thread);
1008         lockres_free(cinfo->message_lockres);
1009         lockres_free(cinfo->token_lockres);
1010         lockres_free(cinfo->ack_lockres);
1011         lockres_free(cinfo->no_new_dev_lockres);
1012         lockres_free(cinfo->resync_lockres);
1013         lockres_free(cinfo->bitmap_lockres);
1014         unlock_all_bitmaps(mddev);
1015         dlm_release_lockspace(cinfo->lockspace, 2);
1016         kfree(cinfo);
1017         return 0;
1018 }
1019
1020 /* slot_number(): Returns the MD slot number to use
1021  * DLM starts the slot numbers from 1, wheras cluster-md
1022  * wants the number to be from zero, so we deduct one
1023  */
1024 static int slot_number(struct mddev *mddev)
1025 {
1026         struct md_cluster_info *cinfo = mddev->cluster_info;
1027
1028         return cinfo->slot_number - 1;
1029 }
1030
1031 /*
1032  * Check if the communication is already locked, else lock the communication
1033  * channel.
1034  * If it is already locked, token is in EX mode, and hence lock_token()
1035  * should not be called.
1036  */
1037 static int metadata_update_start(struct mddev *mddev)
1038 {
1039         struct md_cluster_info *cinfo = mddev->cluster_info;
1040         int ret;
1041
1042         /*
1043          * metadata_update_start is always called with the protection of
1044          * reconfig_mutex, so set WAITING_FOR_TOKEN here.
1045          */
1046         ret = test_and_set_bit_lock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
1047                                     &cinfo->state);
1048         WARN_ON_ONCE(ret);
1049         md_wakeup_thread(mddev->thread);
1050
1051         wait_event(cinfo->wait,
1052                    !test_and_set_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state) ||
1053                    test_and_clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state));
1054
1055         /* If token is already locked, return 0 */
1056         if (cinfo->token_lockres->mode == DLM_LOCK_EX) {
1057                 clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
1058                 return 0;
1059         }
1060
1061         ret = lock_token(cinfo);
1062         clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
1063         return ret;
1064 }
1065
1066 static int metadata_update_finish(struct mddev *mddev)
1067 {
1068         struct md_cluster_info *cinfo = mddev->cluster_info;
1069         struct cluster_msg cmsg;
1070         struct md_rdev *rdev;
1071         int ret = 0;
1072         int raid_slot = -1;
1073
1074         memset(&cmsg, 0, sizeof(cmsg));
1075         cmsg.type = cpu_to_le32(METADATA_UPDATED);
1076         /* Pick up a good active device number to send.
1077          */
1078         rdev_for_each(rdev, mddev)
1079                 if (rdev->raid_disk > -1 && !test_bit(Faulty, &rdev->flags)) {
1080                         raid_slot = rdev->desc_nr;
1081                         break;
1082                 }
1083         if (raid_slot >= 0) {
1084                 cmsg.raid_slot = cpu_to_le32(raid_slot);
1085                 ret = __sendmsg(cinfo, &cmsg);
1086         } else
1087                 pr_warn("md-cluster: No good device id found to send\n");
1088         clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1089         unlock_comm(cinfo);
1090         return ret;
1091 }
1092
1093 static void metadata_update_cancel(struct mddev *mddev)
1094 {
1095         struct md_cluster_info *cinfo = mddev->cluster_info;
1096         clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1097         unlock_comm(cinfo);
1098 }
1099
1100 /*
1101  * return 0 if all the bitmaps have the same sync_size
1102  */
1103 int cluster_check_sync_size(struct mddev *mddev)
1104 {
1105         int i, rv;
1106         bitmap_super_t *sb;
1107         unsigned long my_sync_size, sync_size = 0;
1108         int node_num = mddev->bitmap_info.nodes;
1109         int current_slot = md_cluster_ops->slot_number(mddev);
1110         struct bitmap *bitmap = mddev->bitmap;
1111         char str[64];
1112         struct dlm_lock_resource *bm_lockres;
1113
1114         sb = kmap_atomic(bitmap->storage.sb_page);
1115         my_sync_size = sb->sync_size;
1116         kunmap_atomic(sb);
1117
1118         for (i = 0; i < node_num; i++) {
1119                 if (i == current_slot)
1120                         continue;
1121
1122                 bitmap = get_bitmap_from_slot(mddev, i);
1123                 if (IS_ERR(bitmap)) {
1124                         pr_err("can't get bitmap from slot %d\n", i);
1125                         return -1;
1126                 }
1127
1128                 /*
1129                  * If we can hold the bitmap lock of one node then
1130                  * the slot is not occupied, update the sb.
1131                  */
1132                 snprintf(str, 64, "bitmap%04d", i);
1133                 bm_lockres = lockres_init(mddev, str, NULL, 1);
1134                 if (!bm_lockres) {
1135                         pr_err("md-cluster: Cannot initialize %s\n", str);
1136                         md_bitmap_free(bitmap);
1137                         return -1;
1138                 }
1139                 bm_lockres->flags |= DLM_LKF_NOQUEUE;
1140                 rv = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
1141                 if (!rv)
1142                         bitmap_update_sb(bitmap);
1143                 lockres_free(bm_lockres);
1144
1145                 sb = kmap_atomic(bitmap->storage.sb_page);
1146                 if (sync_size == 0)
1147                         sync_size = sb->sync_size;
1148                 else if (sync_size != sb->sync_size) {
1149                         kunmap_atomic(sb);
1150                         md_bitmap_free(bitmap);
1151                         return -1;
1152                 }
1153                 kunmap_atomic(sb);
1154                 md_bitmap_free(bitmap);
1155         }
1156
1157         return (my_sync_size == sync_size) ? 0 : -1;
1158 }
1159
1160 /*
1161  * Update the size for cluster raid is a little more complex, we perform it
1162  * by the steps:
1163  * 1. hold token lock and update superblock in initiator node.
1164  * 2. send METADATA_UPDATED msg to other nodes.
1165  * 3. The initiator node continues to check each bitmap's sync_size, if all
1166  *    bitmaps have the same value of sync_size, then we can set capacity and
1167  *    let other nodes to perform it. If one node can't update sync_size
1168  *    accordingly, we need to revert to previous value.
1169  */
1170 static void update_size(struct mddev *mddev, sector_t old_dev_sectors)
1171 {
1172         struct md_cluster_info *cinfo = mddev->cluster_info;
1173         struct cluster_msg cmsg;
1174         struct md_rdev *rdev;
1175         int ret = 0;
1176         int raid_slot = -1;
1177
1178         md_update_sb(mddev, 1);
1179         if (lock_comm(cinfo, 1)) {
1180                 pr_err("%s: lock_comm failed\n", __func__);
1181                 return;
1182         }
1183
1184         memset(&cmsg, 0, sizeof(cmsg));
1185         cmsg.type = cpu_to_le32(METADATA_UPDATED);
1186         rdev_for_each(rdev, mddev)
1187                 if (rdev->raid_disk >= 0 && !test_bit(Faulty, &rdev->flags)) {
1188                         raid_slot = rdev->desc_nr;
1189                         break;
1190                 }
1191         if (raid_slot >= 0) {
1192                 cmsg.raid_slot = cpu_to_le32(raid_slot);
1193                 /*
1194                  * We can only change capiticy after all the nodes can do it,
1195                  * so need to wait after other nodes already received the msg
1196                  * and handled the change
1197                  */
1198                 ret = __sendmsg(cinfo, &cmsg);
1199                 if (ret) {
1200                         pr_err("%s:%d: failed to send METADATA_UPDATED msg\n",
1201                                __func__, __LINE__);
1202                         unlock_comm(cinfo);
1203                         return;
1204                 }
1205         } else {
1206                 pr_err("md-cluster: No good device id found to send\n");
1207                 unlock_comm(cinfo);
1208                 return;
1209         }
1210
1211         /*
1212          * check the sync_size from other node's bitmap, if sync_size
1213          * have already updated in other nodes as expected, send an
1214          * empty metadata msg to permit the change of capacity
1215          */
1216         if (cluster_check_sync_size(mddev) == 0) {
1217                 memset(&cmsg, 0, sizeof(cmsg));
1218                 cmsg.type = cpu_to_le32(CHANGE_CAPACITY);
1219                 ret = __sendmsg(cinfo, &cmsg);
1220                 if (ret)
1221                         pr_err("%s:%d: failed to send CHANGE_CAPACITY msg\n",
1222                                __func__, __LINE__);
1223                 set_capacity(mddev->gendisk, mddev->array_sectors);
1224                 revalidate_disk(mddev->gendisk);
1225         } else {
1226                 /* revert to previous sectors */
1227                 ret = mddev->pers->resize(mddev, old_dev_sectors);
1228                 if (!ret)
1229                         revalidate_disk(mddev->gendisk);
1230                 ret = __sendmsg(cinfo, &cmsg);
1231                 if (ret)
1232                         pr_err("%s:%d: failed to send METADATA_UPDATED msg\n",
1233                                __func__, __LINE__);
1234         }
1235         unlock_comm(cinfo);
1236 }
1237
1238 static int resync_start(struct mddev *mddev)
1239 {
1240         struct md_cluster_info *cinfo = mddev->cluster_info;
1241         return dlm_lock_sync_interruptible(cinfo->resync_lockres, DLM_LOCK_EX, mddev);
1242 }
1243
1244 static int resync_info_update(struct mddev *mddev, sector_t lo, sector_t hi)
1245 {
1246         struct md_cluster_info *cinfo = mddev->cluster_info;
1247         struct resync_info ri;
1248         struct cluster_msg cmsg = {0};
1249
1250         /* do not send zero again, if we have sent before */
1251         if (hi == 0) {
1252                 memcpy(&ri, cinfo->bitmap_lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
1253                 if (le64_to_cpu(ri.hi) == 0)
1254                         return 0;
1255         }
1256
1257         add_resync_info(cinfo->bitmap_lockres, lo, hi);
1258         /* Re-acquire the lock to refresh LVB */
1259         dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW);
1260         cmsg.type = cpu_to_le32(RESYNCING);
1261         cmsg.low = cpu_to_le64(lo);
1262         cmsg.high = cpu_to_le64(hi);
1263
1264         /*
1265          * mddev_lock is held if resync_info_update is called from
1266          * resync_finish (md_reap_sync_thread -> resync_finish)
1267          */
1268         if (lo == 0 && hi == 0)
1269                 return sendmsg(cinfo, &cmsg, 1);
1270         else
1271                 return sendmsg(cinfo, &cmsg, 0);
1272 }
1273
1274 static int resync_finish(struct mddev *mddev)
1275 {
1276         struct md_cluster_info *cinfo = mddev->cluster_info;
1277         dlm_unlock_sync(cinfo->resync_lockres);
1278         return resync_info_update(mddev, 0, 0);
1279 }
1280
1281 static int area_resyncing(struct mddev *mddev, int direction,
1282                 sector_t lo, sector_t hi)
1283 {
1284         struct md_cluster_info *cinfo = mddev->cluster_info;
1285         int ret = 0;
1286         struct suspend_info *s;
1287
1288         if ((direction == READ) &&
1289                 test_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state))
1290                 return 1;
1291
1292         spin_lock_irq(&cinfo->suspend_lock);
1293         if (list_empty(&cinfo->suspend_list))
1294                 goto out;
1295         list_for_each_entry(s, &cinfo->suspend_list, list)
1296                 if (hi > s->lo && lo < s->hi) {
1297                         ret = 1;
1298                         break;
1299                 }
1300 out:
1301         spin_unlock_irq(&cinfo->suspend_lock);
1302         return ret;
1303 }
1304
1305 /* add_new_disk() - initiates a disk add
1306  * However, if this fails before writing md_update_sb(),
1307  * add_new_disk_cancel() must be called to release token lock
1308  */
1309 static int add_new_disk(struct mddev *mddev, struct md_rdev *rdev)
1310 {
1311         struct md_cluster_info *cinfo = mddev->cluster_info;
1312         struct cluster_msg cmsg;
1313         int ret = 0;
1314         struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
1315         char *uuid = sb->device_uuid;
1316
1317         memset(&cmsg, 0, sizeof(cmsg));
1318         cmsg.type = cpu_to_le32(NEWDISK);
1319         memcpy(cmsg.uuid, uuid, 16);
1320         cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1321         if (lock_comm(cinfo, 1))
1322                 return -EAGAIN;
1323         ret = __sendmsg(cinfo, &cmsg);
1324         if (ret) {
1325                 unlock_comm(cinfo);
1326                 return ret;
1327         }
1328         cinfo->no_new_dev_lockres->flags |= DLM_LKF_NOQUEUE;
1329         ret = dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_EX);
1330         cinfo->no_new_dev_lockres->flags &= ~DLM_LKF_NOQUEUE;
1331         /* Some node does not "see" the device */
1332         if (ret == -EAGAIN)
1333                 ret = -ENOENT;
1334         if (ret)
1335                 unlock_comm(cinfo);
1336         else {
1337                 dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
1338                 /* Since MD_CHANGE_DEVS will be set in add_bound_rdev which
1339                  * will run soon after add_new_disk, the below path will be
1340                  * invoked:
1341                  *   md_wakeup_thread(mddev->thread)
1342                  *      -> conf->thread (raid1d)
1343                  *      -> md_check_recovery -> md_update_sb
1344                  *      -> metadata_update_start/finish
1345                  * MD_CLUSTER_SEND_LOCKED_ALREADY will be cleared eventually.
1346                  *
1347                  * For other failure cases, metadata_update_cancel and
1348                  * add_new_disk_cancel also clear below bit as well.
1349                  * */
1350                 set_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1351                 wake_up(&cinfo->wait);
1352         }
1353         return ret;
1354 }
1355
1356 static void add_new_disk_cancel(struct mddev *mddev)
1357 {
1358         struct md_cluster_info *cinfo = mddev->cluster_info;
1359         clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
1360         unlock_comm(cinfo);
1361 }
1362
1363 static int new_disk_ack(struct mddev *mddev, bool ack)
1364 {
1365         struct md_cluster_info *cinfo = mddev->cluster_info;
1366
1367         if (!test_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state)) {
1368                 pr_warn("md-cluster(%s): Spurious cluster confirmation\n", mdname(mddev));
1369                 return -EINVAL;
1370         }
1371
1372         if (ack)
1373                 dlm_unlock_sync(cinfo->no_new_dev_lockres);
1374         complete(&cinfo->newdisk_completion);
1375         return 0;
1376 }
1377
1378 static int remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1379 {
1380         struct cluster_msg cmsg = {0};
1381         struct md_cluster_info *cinfo = mddev->cluster_info;
1382         cmsg.type = cpu_to_le32(REMOVE);
1383         cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1384         return sendmsg(cinfo, &cmsg, 1);
1385 }
1386
1387 static int lock_all_bitmaps(struct mddev *mddev)
1388 {
1389         int slot, my_slot, ret, held = 1, i = 0;
1390         char str[64];
1391         struct md_cluster_info *cinfo = mddev->cluster_info;
1392
1393         cinfo->other_bitmap_lockres = kzalloc((mddev->bitmap_info.nodes - 1) *
1394                                              sizeof(struct dlm_lock_resource *),
1395                                              GFP_KERNEL);
1396         if (!cinfo->other_bitmap_lockres) {
1397                 pr_err("md: can't alloc mem for other bitmap locks\n");
1398                 return 0;
1399         }
1400
1401         my_slot = slot_number(mddev);
1402         for (slot = 0; slot < mddev->bitmap_info.nodes; slot++) {
1403                 if (slot == my_slot)
1404                         continue;
1405
1406                 memset(str, '\0', 64);
1407                 snprintf(str, 64, "bitmap%04d", slot);
1408                 cinfo->other_bitmap_lockres[i] = lockres_init(mddev, str, NULL, 1);
1409                 if (!cinfo->other_bitmap_lockres[i])
1410                         return -ENOMEM;
1411
1412                 cinfo->other_bitmap_lockres[i]->flags |= DLM_LKF_NOQUEUE;
1413                 ret = dlm_lock_sync(cinfo->other_bitmap_lockres[i], DLM_LOCK_PW);
1414                 if (ret)
1415                         held = -1;
1416                 i++;
1417         }
1418
1419         return held;
1420 }
1421
1422 static void unlock_all_bitmaps(struct mddev *mddev)
1423 {
1424         struct md_cluster_info *cinfo = mddev->cluster_info;
1425         int i;
1426
1427         /* release other node's bitmap lock if they are existed */
1428         if (cinfo->other_bitmap_lockres) {
1429                 for (i = 0; i < mddev->bitmap_info.nodes - 1; i++) {
1430                         if (cinfo->other_bitmap_lockres[i]) {
1431                                 lockres_free(cinfo->other_bitmap_lockres[i]);
1432                         }
1433                 }
1434                 kfree(cinfo->other_bitmap_lockres);
1435                 cinfo->other_bitmap_lockres = NULL;
1436         }
1437 }
1438
1439 static int gather_bitmaps(struct md_rdev *rdev)
1440 {
1441         int sn, err;
1442         sector_t lo, hi;
1443         struct cluster_msg cmsg = {0};
1444         struct mddev *mddev = rdev->mddev;
1445         struct md_cluster_info *cinfo = mddev->cluster_info;
1446
1447         cmsg.type = cpu_to_le32(RE_ADD);
1448         cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
1449         err = sendmsg(cinfo, &cmsg, 1);
1450         if (err)
1451                 goto out;
1452
1453         for (sn = 0; sn < mddev->bitmap_info.nodes; sn++) {
1454                 if (sn == (cinfo->slot_number - 1))
1455                         continue;
1456                 err = bitmap_copy_from_slot(mddev, sn, &lo, &hi, false);
1457                 if (err) {
1458                         pr_warn("md-cluster: Could not gather bitmaps from slot %d", sn);
1459                         goto out;
1460                 }
1461                 if ((hi > 0) && (lo < mddev->recovery_cp))
1462                         mddev->recovery_cp = lo;
1463         }
1464 out:
1465         return err;
1466 }
1467
1468 static struct md_cluster_operations cluster_ops = {
1469         .join   = join,
1470         .leave  = leave,
1471         .slot_number = slot_number,
1472         .resync_start = resync_start,
1473         .resync_finish = resync_finish,
1474         .resync_info_update = resync_info_update,
1475         .metadata_update_start = metadata_update_start,
1476         .metadata_update_finish = metadata_update_finish,
1477         .metadata_update_cancel = metadata_update_cancel,
1478         .area_resyncing = area_resyncing,
1479         .add_new_disk = add_new_disk,
1480         .add_new_disk_cancel = add_new_disk_cancel,
1481         .new_disk_ack = new_disk_ack,
1482         .remove_disk = remove_disk,
1483         .load_bitmaps = load_bitmaps,
1484         .gather_bitmaps = gather_bitmaps,
1485         .lock_all_bitmaps = lock_all_bitmaps,
1486         .unlock_all_bitmaps = unlock_all_bitmaps,
1487         .update_size = update_size,
1488 };
1489
1490 static int __init cluster_init(void)
1491 {
1492         pr_warn("md-cluster: EXPERIMENTAL. Use with caution\n");
1493         pr_info("Registering Cluster MD functions\n");
1494         register_md_cluster_operations(&cluster_ops, THIS_MODULE);
1495         return 0;
1496 }
1497
1498 static void cluster_exit(void)
1499 {
1500         unregister_md_cluster_operations();
1501 }
1502
1503 module_init(cluster_init);
1504 module_exit(cluster_exit);
1505 MODULE_AUTHOR("SUSE");
1506 MODULE_LICENSE("GPL");
1507 MODULE_DESCRIPTION("Clustering support for MD");