fs/ocfs2/cluster/heartbeat.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * Copyright (C) 2004, 2005 Oracle.  All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public
  17  * License along with this program; if not, write to the
  18  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19  * Boston, MA 021110-1307, USA.
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/sched.h>
  24 #include <linux/jiffies.h>
  25 #include <linux/module.h>
  26 #include <linux/fs.h>
  27 #include <linux/bio.h>
  28 #include <linux/blkdev.h>
  29 #include <linux/delay.h>
  30 #include <linux/file.h>
  31 #include <linux/kthread.h>
  32 #include <linux/configfs.h>
  33 #include <linux/random.h>
  34 #include <linux/crc32.h>
  35 #include <linux/time.h>
  36 #include <linux/debugfs.h>
  37 #include <linux/slab.h>
  38
  39 #include "heartbeat.h"
  40 #include "tcp.h"
  41 #include "nodemanager.h"
  42 #include "quorum.h"
  43
  44 #include "masklog.h"
  45
  46
  47 /*
  48  * The first heartbeat pass had one global thread that would serialize all hb
  49  * callback calls.  This global serializing sem should only be removed once
  50  * we've made sure that all callees can deal with being called concurrently
  51  * from multiple hb region threads.
  52  */
  53 static DECLARE_RWSEM(o2hb_callback_sem);
  54
  55 /*
  56  * multiple hb threads are watching multiple regions.  A node is live
  57  * whenever any of the threads sees activity from the node in its region.
  58  */
  59 static DEFINE_SPINLOCK(o2hb_live_lock);
  60 static struct list_head o2hb_live_slots[O2NM_MAX_NODES];
  61 static unsigned long o2hb_live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
  62 static LIST_HEAD(o2hb_node_events);
  63 static DECLARE_WAIT_QUEUE_HEAD(o2hb_steady_queue);
  64
  65 /*
  66  * In global heartbeat, we maintain a series of region bitmaps.
  67  *      - o2hb_region_bitmap allows us to limit the region number to max region.
  68  *      - o2hb_live_region_bitmap tracks live regions (seen steady iterations).
  69  *      - o2hb_quorum_region_bitmap tracks live regions that have seen all nodes
  70  *              heartbeat on it.
  71  *      - o2hb_failed_region_bitmap tracks the regions that have seen io timeouts.
  72  */
  73 static unsigned long o2hb_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
  74 static unsigned long o2hb_live_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
  75 static unsigned long o2hb_quorum_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
  76 static unsigned long o2hb_failed_region_bitmap[BITS_TO_LONGS(O2NM_MAX_REGIONS)];
  77
  78 #define O2HB_DB_TYPE_LIVENODES          0
  79 #define O2HB_DB_TYPE_LIVEREGIONS        1
  80 #define O2HB_DB_TYPE_QUORUMREGIONS      2
  81 #define O2HB_DB_TYPE_FAILEDREGIONS      3
  82 #define O2HB_DB_TYPE_REGION_LIVENODES   4
  83 #define O2HB_DB_TYPE_REGION_NUMBER      5
  84 #define O2HB_DB_TYPE_REGION_ELAPSED_TIME        6
  85 #define O2HB_DB_TYPE_REGION_PINNED      7
  86 struct o2hb_debug_buf {
  87         int db_type;
  88         int db_size;
  89         int db_len;
  90         void *db_data;
  91 };
  92
  93 static struct o2hb_debug_buf *o2hb_db_livenodes;
  94 static struct o2hb_debug_buf *o2hb_db_liveregions;
  95 static struct o2hb_debug_buf *o2hb_db_quorumregions;
  96 static struct o2hb_debug_buf *o2hb_db_failedregions;
  97
  98 #define O2HB_DEBUG_DIR                  "o2hb"
  99 #define O2HB_DEBUG_LIVENODES            "livenodes"
 100 #define O2HB_DEBUG_LIVEREGIONS          "live_regions"
 101 #define O2HB_DEBUG_QUORUMREGIONS        "quorum_regions"
 102 #define O2HB_DEBUG_FAILEDREGIONS        "failed_regions"
 103 #define O2HB_DEBUG_REGION_NUMBER        "num"
 104 #define O2HB_DEBUG_REGION_ELAPSED_TIME  "elapsed_time_in_ms"
 105 #define O2HB_DEBUG_REGION_PINNED        "pinned"
 106
 107 static struct dentry *o2hb_debug_dir;
 108 static struct dentry *o2hb_debug_livenodes;
 109 static struct dentry *o2hb_debug_liveregions;
 110 static struct dentry *o2hb_debug_quorumregions;
 111 static struct dentry *o2hb_debug_failedregions;
 112
 113 static LIST_HEAD(o2hb_all_regions);
 114
 115 static struct o2hb_callback {
 116         struct list_head list;
 117 } o2hb_callbacks[O2HB_NUM_CB];
 118
 119 static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type);
 120
 121 #define O2HB_DEFAULT_BLOCK_BITS       9
 122
 123 enum o2hb_heartbeat_modes {
 124         O2HB_HEARTBEAT_LOCAL            = 0,
 125         O2HB_HEARTBEAT_GLOBAL,
 126         O2HB_HEARTBEAT_NUM_MODES,
 127 };
 128
 129 char *o2hb_heartbeat_mode_desc[O2HB_HEARTBEAT_NUM_MODES] = {
 130                 "local",        /* O2HB_HEARTBEAT_LOCAL */
 131                 "global",       /* O2HB_HEARTBEAT_GLOBAL */
 132 };
 133
 134 unsigned int o2hb_dead_threshold = O2HB_DEFAULT_DEAD_THRESHOLD;
 135 unsigned int o2hb_heartbeat_mode = O2HB_HEARTBEAT_LOCAL;
 136
 137 /*
 138  * o2hb_dependent_users tracks the number of registered callbacks that depend
 139  * on heartbeat. o2net and o2dlm are two entities that register this callback.
 140  * However only o2dlm depends on the heartbeat. It does not want the heartbeat
 141  * to stop while a dlm domain is still active.
 142  */
 143 unsigned int o2hb_dependent_users;
 144
 145 /*
 146  * In global heartbeat mode, all regions are pinned if there are one or more
 147  * dependent users and the quorum region count is <= O2HB_PIN_CUT_OFF. All
 148  * regions are unpinned if the region count exceeds the cut off or the number
 149  * of dependent users falls to zero.
 150  */
 151 #define O2HB_PIN_CUT_OFF                3
 152
 153 /*
 154  * In local heartbeat mode, we assume the dlm domain name to be the same as
 155  * region uuid. This is true for domains created for the file system but not
 156  * necessarily true for userdlm domains. This is a known limitation.
 157  *
 158  * In global heartbeat mode, we pin/unpin all o2hb regions. This solution
 159  * works for both file system and userdlm domains.
 160  */
 161 static int o2hb_region_pin(const char *region_uuid);
 162 static void o2hb_region_unpin(const char *region_uuid);
 163
 164 /* Only sets a new threshold if there are no active regions.
 165  *
 166  * No locking or otherwise interesting code is required for reading
 167  * o2hb_dead_threshold as it can't change once regions are active and
 168  * it's not interesting to anyone until then anyway. */
 169 static void o2hb_dead_threshold_set(unsigned int threshold)
 170 {
 171         if (threshold > O2HB_MIN_DEAD_THRESHOLD) {
 172                 spin_lock(&o2hb_live_lock);
 173                 if (list_empty(&o2hb_all_regions))
 174                         o2hb_dead_threshold = threshold;
 175                 spin_unlock(&o2hb_live_lock);
 176         }
 177 }
 178
 179 static int o2hb_global_hearbeat_mode_set(unsigned int hb_mode)
 180 {
 181         int ret = -1;
 182
 183         if (hb_mode < O2HB_HEARTBEAT_NUM_MODES) {
 184                 spin_lock(&o2hb_live_lock);
 185                 if (list_empty(&o2hb_all_regions)) {
 186                         o2hb_heartbeat_mode = hb_mode;
 187                         ret = 0;
 188                 }
 189                 spin_unlock(&o2hb_live_lock);
 190         }
 191
 192         return ret;
 193 }
 194
 195 struct o2hb_node_event {
 196         struct list_head        hn_item;
 197         enum o2hb_callback_type hn_event_type;
 198         struct o2nm_node        *hn_node;
 199         int                     hn_node_num;
 200 };
 201
 202 struct o2hb_disk_slot {
 203         struct o2hb_disk_heartbeat_block *ds_raw_block;
 204         u8                      ds_node_num;
 205         u64                     ds_last_time;
 206         u64                     ds_last_generation;
 207         u16                     ds_equal_samples;
 208         u16                     ds_changed_samples;
 209         struct list_head        ds_live_item;
 210 };
 211
 212 /* each thread owns a region.. when we're asked to tear down the region
 213  * we ask the thread to stop, who cleans up the region */
 214 struct o2hb_region {
 215         struct config_item      hr_item;
 216
 217         struct list_head        hr_all_item;
 218         unsigned                hr_unclean_stop:1,
 219                                 hr_item_pinned:1,
 220                                 hr_item_dropped:1;
 221
 222         /* protected by the hr_callback_sem */
 223         struct task_struct      *hr_task;
 224
 225         unsigned int            hr_blocks;
 226         unsigned long long      hr_start_block;
 227
 228         unsigned int            hr_block_bits;
 229         unsigned int            hr_block_bytes;
 230
 231         unsigned int            hr_slots_per_page;
 232         unsigned int            hr_num_pages;
 233
 234         struct page             **hr_slot_data;
 235         struct block_device     *hr_bdev;
 236         struct o2hb_disk_slot   *hr_slots;
 237
 238         /* live node map of this region */
 239         unsigned long           hr_live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
 240         unsigned int            hr_region_num;
 241
 242         struct dentry           *hr_debug_dir;
 243         struct dentry           *hr_debug_livenodes;
 244         struct dentry           *hr_debug_regnum;
 245         struct dentry           *hr_debug_elapsed_time;
 246         struct dentry           *hr_debug_pinned;
 247         struct o2hb_debug_buf   *hr_db_livenodes;
 248         struct o2hb_debug_buf   *hr_db_regnum;
 249         struct o2hb_debug_buf   *hr_db_elapsed_time;
 250         struct o2hb_debug_buf   *hr_db_pinned;
 251
 252         /* let the person setting up hb wait for it to return until it
 253          * has reached a 'steady' state.  This will be fixed when we have
 254          * a more complete api that doesn't lead to this sort of fragility. */
 255         atomic_t                hr_steady_iterations;
 256
 257         char                    hr_dev_name[BDEVNAME_SIZE];
 258
 259         unsigned int            hr_timeout_ms;
 260
 261         /* randomized as the region goes up and down so that a node
 262          * recognizes a node going up and down in one iteration */
 263         u64                     hr_generation;
 264
 265         struct delayed_work     hr_write_timeout_work;
 266         unsigned long           hr_last_timeout_start;
 267
 268         /* Used during o2hb_check_slot to hold a copy of the block
 269          * being checked because we temporarily have to zero out the
 270          * crc field. */
 271         struct o2hb_disk_heartbeat_block *hr_tmp_block;
 272 };
 273
 274 struct o2hb_bio_wait_ctxt {
 275         atomic_t          wc_num_reqs;
 276         struct completion wc_io_complete;
 277         int               wc_error;
 278 };
 279
 280 static int o2hb_pop_count(void *map, int count)
 281 {
 282         int i = -1, pop = 0;
 283
 284         while ((i = find_next_bit(map, count, i + 1)) < count)
 285                 pop++;
 286         return pop;
 287 }
 288
 289 static void o2hb_write_timeout(struct work_struct *work)
 290 {
 291         int failed, quorum;
 292         unsigned long flags;
 293         struct o2hb_region *reg =
 294                 container_of(work, struct o2hb_region,
 295                              hr_write_timeout_work.work);
 296
 297         mlog(ML_ERROR, "Heartbeat write timeout to device %s after %u "
 298              "milliseconds\n", reg->hr_dev_name,
 299              jiffies_to_msecs(jiffies - reg->hr_last_timeout_start));
 300
 301         if (o2hb_global_heartbeat_active()) {
 302                 spin_lock_irqsave(&o2hb_live_lock, flags);
 303                 if (test_bit(reg->hr_region_num, o2hb_quorum_region_bitmap))
 304                         set_bit(reg->hr_region_num, o2hb_failed_region_bitmap);
 305                 failed = o2hb_pop_count(&o2hb_failed_region_bitmap,
 306                                         O2NM_MAX_REGIONS);
 307                 quorum = o2hb_pop_count(&o2hb_quorum_region_bitmap,
 308                                         O2NM_MAX_REGIONS);
 309                 spin_unlock_irqrestore(&o2hb_live_lock, flags);
 310
 311                 mlog(ML_HEARTBEAT, "Number of regions %d, failed regions %d\n",
 312                      quorum, failed);
 313
 314                 /*
 315                  * Fence if the number of failed regions >= half the number
 316                  * of  quorum regions
 317                  */
 318                 if ((failed << 1) < quorum)
 319                         return;
 320         }
 321
 322         o2quo_disk_timeout();
 323 }
 324
 325 static void o2hb_arm_write_timeout(struct o2hb_region *reg)
 326 {
 327         mlog(ML_HEARTBEAT, "Queue write timeout for %u ms\n",
 328              O2HB_MAX_WRITE_TIMEOUT_MS);
 329
 330         if (o2hb_global_heartbeat_active()) {
 331                 spin_lock(&o2hb_live_lock);
 332                 clear_bit(reg->hr_region_num, o2hb_failed_region_bitmap);
 333                 spin_unlock(&o2hb_live_lock);
 334         }
 335         cancel_delayed_work(&reg->hr_write_timeout_work);
 336         reg->hr_last_timeout_start = jiffies;
 337         schedule_delayed_work(&reg->hr_write_timeout_work,
 338                               msecs_to_jiffies(O2HB_MAX_WRITE_TIMEOUT_MS));
 339 }
 340
 341 static void o2hb_disarm_write_timeout(struct o2hb_region *reg)
 342 {
 343         cancel_delayed_work_sync(&reg->hr_write_timeout_work);
 344 }
 345
 346 static inline void o2hb_bio_wait_init(struct o2hb_bio_wait_ctxt *wc)
 347 {
 348         atomic_set(&wc->wc_num_reqs, 1);
 349         init_completion(&wc->wc_io_complete);
 350         wc->wc_error = 0;
 351 }
 352
 353 /* Used in error paths too */
 354 static inline void o2hb_bio_wait_dec(struct o2hb_bio_wait_ctxt *wc,
 355                                      unsigned int num)
 356 {
 357         /* sadly atomic_sub_and_test() isn't available on all platforms.  The
 358          * good news is that the fast path only completes one at a time */
 359         while(num--) {
 360                 if (atomic_dec_and_test(&wc->wc_num_reqs)) {
 361                         BUG_ON(num > 0);
 362                         complete(&wc->wc_io_complete);
 363                 }
 364         }
 365 }
 366
 367 static void o2hb_wait_on_io(struct o2hb_region *reg,
 368                             struct o2hb_bio_wait_ctxt *wc)
 369 {
 370         o2hb_bio_wait_dec(wc, 1);
 371         wait_for_completion(&wc->wc_io_complete);
 372 }
 373
 374 static void o2hb_bio_end_io(struct bio *bio,
 375                            int error)
 376 {
 377         struct o2hb_bio_wait_ctxt *wc = bio->bi_private;
 378
 379         if (error) {
 380                 mlog(ML_ERROR, "IO Error %d\n", error);
 381                 wc->wc_error = error;
 382         }
 383
 384         o2hb_bio_wait_dec(wc, 1);
 385         bio_put(bio);
 386 }
 387
 388 /* Setup a Bio to cover I/O against num_slots slots starting at
 389  * start_slot. */
 390 static struct bio *o2hb_setup_one_bio(struct o2hb_region *reg,
 391                                       struct o2hb_bio_wait_ctxt *wc,
 392                                       unsigned int *current_slot,
 393                                       unsigned int max_slots)
 394 {
 395         int len, current_page;
 396         unsigned int vec_len, vec_start;
 397         unsigned int bits = reg->hr_block_bits;
 398         unsigned int spp = reg->hr_slots_per_page;
 399         unsigned int cs = *current_slot;
 400         struct bio *bio;
 401         struct page *page;
 402
 403         /* Testing has shown this allocation to take long enough under
 404          * GFP_KERNEL that the local node can get fenced. It would be
 405          * nicest if we could pre-allocate these bios and avoid this
 406          * all together. */
 407         bio = bio_alloc(GFP_ATOMIC, 16);
 408         if (!bio) {
 409                 mlog(ML_ERROR, "Could not alloc slots BIO!\n");
 410                 bio = ERR_PTR(-ENOMEM);
 411                 goto bail;
 412         }
 413
 414         /* Must put everything in 512 byte sectors for the bio... */
 415         bio->bi_sector = (reg->hr_start_block + cs) << (bits - 9);
 416         bio->bi_bdev = reg->hr_bdev;
 417         bio->bi_private = wc;
 418         bio->bi_end_io = o2hb_bio_end_io;
 419
 420         vec_start = (cs << bits) % PAGE_CACHE_SIZE;
 421         while(cs < max_slots) {
 422                 current_page = cs / spp;
 423                 page = reg->hr_slot_data[current_page];
 424
 425                 vec_len = min(PAGE_CACHE_SIZE - vec_start,
 426                               (max_slots-cs) * (PAGE_CACHE_SIZE/spp) );
 427
 428                 mlog(ML_HB_BIO, "page %d, vec_len = %u, vec_start = %u\n",
 429                      current_page, vec_len, vec_start);
 430
 431                 len = bio_add_page(bio, page, vec_len, vec_start);
 432                 if (len != vec_len) break;
 433
 434                 cs += vec_len / (PAGE_CACHE_SIZE/spp);
 435                 vec_start = 0;
 436         }
 437
 438 bail:
 439         *current_slot = cs;
 440         return bio;
 441 }
 442
 443 static int o2hb_read_slots(struct o2hb_region *reg,
 444                            unsigned int max_slots)
 445 {
 446         unsigned int current_slot=0;
 447         int status;
 448         struct o2hb_bio_wait_ctxt wc;
 449         struct bio *bio;
 450
 451         o2hb_bio_wait_init(&wc);
 452
 453         while(current_slot < max_slots) {
 454                 bio = o2hb_setup_one_bio(reg, &wc, &current_slot, max_slots);
 455                 if (IS_ERR(bio)) {
 456                         status = PTR_ERR(bio);
 457                         mlog_errno(status);
 458                         goto bail_and_wait;
 459                 }
 460
 461                 atomic_inc(&wc.wc_num_reqs);
 462                 submit_bio(READ, bio);
 463         }
 464
 465         status = 0;
 466
 467 bail_and_wait:
 468         o2hb_wait_on_io(reg, &wc);
 469         if (wc.wc_error && !status)
 470                 status = wc.wc_error;
 471
 472         return status;
 473 }
 474
 475 static int o2hb_issue_node_write(struct o2hb_region *reg,
 476                                  struct o2hb_bio_wait_ctxt *write_wc)
 477 {
 478         int status;
 479         unsigned int slot;
 480         struct bio *bio;
 481
 482         o2hb_bio_wait_init(write_wc);
 483
 484         slot = o2nm_this_node();
 485
 486         bio = o2hb_setup_one_bio(reg, write_wc, &slot, slot+1);
 487         if (IS_ERR(bio)) {
 488                 status = PTR_ERR(bio);
 489                 mlog_errno(status);
 490                 goto bail;
 491         }
 492
 493         atomic_inc(&write_wc->wc_num_reqs);
 494         submit_bio(WRITE, bio);
 495
 496         status = 0;
 497 bail:
 498         return status;
 499 }
 500
 501 static u32 o2hb_compute_block_crc_le(struct o2hb_region *reg,
 502                                      struct o2hb_disk_heartbeat_block *hb_block)
 503 {
 504         __le32 old_cksum;
 505         u32 ret;
 506
 507         /* We want to compute the block crc with a 0 value in the
 508          * hb_cksum field. Save it off here and replace after the
 509          * crc. */
 510         old_cksum = hb_block->hb_cksum;
 511         hb_block->hb_cksum = 0;
 512
 513         ret = crc32_le(0, (unsigned char *) hb_block, reg->hr_block_bytes);
 514
 515         hb_block->hb_cksum = old_cksum;
 516
 517         return ret;
 518 }
 519
 520 static void o2hb_dump_slot(struct o2hb_disk_heartbeat_block *hb_block)
 521 {
 522         mlog(ML_ERROR, "Dump slot information: seq = 0x%llx, node = %u, "
 523              "cksum = 0x%x, generation 0x%llx\n",
 524              (long long)le64_to_cpu(hb_block->hb_seq),
 525              hb_block->hb_node, le32_to_cpu(hb_block->hb_cksum),
 526              (long long)le64_to_cpu(hb_block->hb_generation));
 527 }
 528
 529 static int o2hb_verify_crc(struct o2hb_region *reg,
 530                            struct o2hb_disk_heartbeat_block *hb_block)
 531 {
 532         u32 read, computed;
 533
 534         read = le32_to_cpu(hb_block->hb_cksum);
 535         computed = o2hb_compute_block_crc_le(reg, hb_block);
 536
 537         return read == computed;
 538 }
 539
 540 /* We want to make sure that nobody is heartbeating on top of us --
 541  * this will help detect an invalid configuration. */
 542 static int o2hb_check_last_timestamp(struct o2hb_region *reg)
 543 {
 544         int node_num, ret;
 545         struct o2hb_disk_slot *slot;
 546         struct o2hb_disk_heartbeat_block *hb_block;
 547
 548         node_num = o2nm_this_node();
 549
 550         ret = 1;
 551         slot = &reg->hr_slots[node_num];
 552         /* Don't check on our 1st timestamp */
 553         if (slot->ds_last_time) {
 554                 hb_block = slot->ds_raw_block;
 555
 556                 if (le64_to_cpu(hb_block->hb_seq) != slot->ds_last_time)
 557                         ret = 0;
 558         }
 559
 560         return ret;
 561 }
 562
 563 static inline void o2hb_prepare_block(struct o2hb_region *reg,
 564                                       u64 generation)
 565 {
 566         int node_num;
 567         u64 cputime;
 568         struct o2hb_disk_slot *slot;
 569         struct o2hb_disk_heartbeat_block *hb_block;
 570
 571         node_num = o2nm_this_node();
 572         slot = &reg->hr_slots[node_num];
 573
 574         hb_block = (struct o2hb_disk_heartbeat_block *)slot->ds_raw_block;
 575         memset(hb_block, 0, reg->hr_block_bytes);
 576         /* TODO: time stuff */
 577         cputime = CURRENT_TIME.tv_sec;
 578         if (!cputime)
 579                 cputime = 1;
 580
 581         hb_block->hb_seq = cpu_to_le64(cputime);
 582         hb_block->hb_node = node_num;
 583         hb_block->hb_generation = cpu_to_le64(generation);
 584         hb_block->hb_dead_ms = cpu_to_le32(o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS);
 585
 586         /* This step must always happen last! */
 587         hb_block->hb_cksum = cpu_to_le32(o2hb_compute_block_crc_le(reg,
 588                                                                    hb_block));
 589
 590         mlog(ML_HB_BIO, "our node generation = 0x%llx, cksum = 0x%x\n",
 591              (long long)generation,
 592              le32_to_cpu(hb_block->hb_cksum));
 593 }
 594
 595 static void o2hb_fire_callbacks(struct o2hb_callback *hbcall,
 596                                 struct o2nm_node *node,
 597                                 int idx)
 598 {
 599         struct list_head *iter;
 600         struct o2hb_callback_func *f;
 601
 602         list_for_each(iter, &hbcall->list) {
 603                 f = list_entry(iter, struct o2hb_callback_func, hc_item);
 604                 mlog(ML_HEARTBEAT, "calling funcs %p\n", f);
 605                 (f->hc_func)(node, idx, f->hc_data);
 606         }
 607 }
 608
 609 /* Will run the list in order until we process the passed event */
 610 static void o2hb_run_event_list(struct o2hb_node_event *queued_event)
 611 {
 612         int empty;
 613         struct o2hb_callback *hbcall;
 614         struct o2hb_node_event *event;
 615
 616         spin_lock(&o2hb_live_lock);
 617         empty = list_empty(&queued_event->hn_item);
 618         spin_unlock(&o2hb_live_lock);
 619         if (empty)
 620                 return;
 621
 622         /* Holding callback sem assures we don't alter the callback
 623          * lists when doing this, and serializes ourselves with other
 624          * processes wanting callbacks. */
 625         down_write(&o2hb_callback_sem);
 626
 627         spin_lock(&o2hb_live_lock);
 628         while (!list_empty(&o2hb_node_events)
 629                && !list_empty(&queued_event->hn_item)) {
 630                 event = list_entry(o2hb_node_events.next,
 631                                    struct o2hb_node_event,
 632                                    hn_item);
 633                 list_del_init(&event->hn_item);
 634                 spin_unlock(&o2hb_live_lock);
 635
 636                 mlog(ML_HEARTBEAT, "Node %s event for %d\n",
 637                      event->hn_event_type == O2HB_NODE_UP_CB ? "UP" : "DOWN",
 638                      event->hn_node_num);
 639
 640                 hbcall = hbcall_from_type(event->hn_event_type);
 641
 642                 /* We should *never* have gotten on to the list with a
 643                  * bad type... This isn't something that we should try
 644                  * to recover from. */
 645                 BUG_ON(IS_ERR(hbcall));
 646
 647                 o2hb_fire_callbacks(hbcall, event->hn_node, event->hn_node_num);
 648
 649                 spin_lock(&o2hb_live_lock);
 650         }
 651         spin_unlock(&o2hb_live_lock);
 652
 653         up_write(&o2hb_callback_sem);
 654 }
 655
 656 static void o2hb_queue_node_event(struct o2hb_node_event *event,
 657                                   enum o2hb_callback_type type,
 658                                   struct o2nm_node *node,
 659                                   int node_num)
 660 {
 661         assert_spin_locked(&o2hb_live_lock);
 662
 663         BUG_ON((!node) && (type != O2HB_NODE_DOWN_CB));
 664
 665         event->hn_event_type = type;
 666         event->hn_node = node;
 667         event->hn_node_num = node_num;
 668
 669         mlog(ML_HEARTBEAT, "Queue node %s event for node %d\n",
 670              type == O2HB_NODE_UP_CB ? "UP" : "DOWN", node_num);
 671
 672         list_add_tail(&event->hn_item, &o2hb_node_events);
 673 }
 674
 675 static void o2hb_shutdown_slot(struct o2hb_disk_slot *slot)
 676 {
 677         struct o2hb_node_event event =
 678                 { .hn_item = LIST_HEAD_INIT(event.hn_item), };
 679         struct o2nm_node *node;
 680
 681         node = o2nm_get_node_by_num(slot->ds_node_num);
 682         if (!node)
 683                 return;
 684
 685         spin_lock(&o2hb_live_lock);
 686         if (!list_empty(&slot->ds_live_item)) {
 687                 mlog(ML_HEARTBEAT, "Shutdown, node %d leaves region\n",
 688                      slot->ds_node_num);
 689
 690                 list_del_init(&slot->ds_live_item);
 691
 692                 if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
 693                         clear_bit(slot->ds_node_num, o2hb_live_node_bitmap);
 694
 695                         o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB, node,
 696                                               slot->ds_node_num);
 697                 }
 698         }
 699         spin_unlock(&o2hb_live_lock);
 700
 701         o2hb_run_event_list(&event);
 702
 703         o2nm_node_put(node);
 704 }
 705
 706 static void o2hb_set_quorum_device(struct o2hb_region *reg,
 707                                    struct o2hb_disk_slot *slot)
 708 {
 709         assert_spin_locked(&o2hb_live_lock);
 710
 711         if (!o2hb_global_heartbeat_active())
 712                 return;
 713
 714         if (test_bit(reg->hr_region_num, o2hb_quorum_region_bitmap))
 715                 return;
 716
 717         /*
 718          * A region can be added to the quorum only when it sees all
 719          * live nodes heartbeat on it. In other words, the region has been
 720          * added to all nodes.
 721          */
 722         if (memcmp(reg->hr_live_node_bitmap, o2hb_live_node_bitmap,
 723                    sizeof(o2hb_live_node_bitmap)))
 724                 return;
 725
 726         if (slot->ds_changed_samples < O2HB_LIVE_THRESHOLD)
 727                 return;
 728
 729         printk(KERN_NOTICE "o2hb: Region %s is now a quorum device\n",
 730                config_item_name(&reg->hr_item));
 731
 732         set_bit(reg->hr_region_num, o2hb_quorum_region_bitmap);
 733
 734         /*
 735          * If global heartbeat active, unpin all regions if the
 736          * region count > CUT_OFF
 737          */
 738         if (o2hb_pop_count(&o2hb_quorum_region_bitmap,
 739                            O2NM_MAX_REGIONS) > O2HB_PIN_CUT_OFF)
 740                 o2hb_region_unpin(NULL);
 741 }
 742
 743 static int o2hb_check_slot(struct o2hb_region *reg,
 744                            struct o2hb_disk_slot *slot)
 745 {
 746         int changed = 0, gen_changed = 0;
 747         struct o2hb_node_event event =
 748                 { .hn_item = LIST_HEAD_INIT(event.hn_item), };
 749         struct o2nm_node *node;
 750         struct o2hb_disk_heartbeat_block *hb_block = reg->hr_tmp_block;
 751         u64 cputime;
 752         unsigned int dead_ms = o2hb_dead_threshold * O2HB_REGION_TIMEOUT_MS;
 753         unsigned int slot_dead_ms;
 754         int tmp;
 755
 756         memcpy(hb_block, slot->ds_raw_block, reg->hr_block_bytes);
 757
 758         /*
 759          * If a node is no longer configured but is still in the livemap, we
 760          * may need to clear that bit from the livemap.
 761          */
 762         node = o2nm_get_node_by_num(slot->ds_node_num);
 763         if (!node) {
 764                 spin_lock(&o2hb_live_lock);
 765                 tmp = test_bit(slot->ds_node_num, o2hb_live_node_bitmap);
 766                 spin_unlock(&o2hb_live_lock);
 767                 if (!tmp)
 768                         return 0;
 769         }
 770
 771         if (!o2hb_verify_crc(reg, hb_block)) {
 772                 /* all paths from here will drop o2hb_live_lock for
 773                  * us. */
 774                 spin_lock(&o2hb_live_lock);
 775
 776                 /* Don't print an error on the console in this case -
 777                  * a freshly formatted heartbeat area will not have a
 778                  * crc set on it. */
 779                 if (list_empty(&slot->ds_live_item))
 780                         goto out;
 781
 782                 /* The node is live but pushed out a bad crc. We
 783                  * consider it a transient miss but don't populate any
 784                  * other values as they may be junk. */
 785                 mlog(ML_ERROR, "Node %d has written a bad crc to %s\n",
 786                      slot->ds_node_num, reg->hr_dev_name);
 787                 o2hb_dump_slot(hb_block);
 788
 789                 slot->ds_equal_samples++;
 790                 goto fire_callbacks;
 791         }
 792
 793         /* we don't care if these wrap.. the state transitions below
 794          * clear at the right places */
 795         cputime = le64_to_cpu(hb_block->hb_seq);
 796         if (slot->ds_last_time != cputime)
 797                 slot->ds_changed_samples++;
 798         else
 799                 slot->ds_equal_samples++;
 800         slot->ds_last_time = cputime;
 801
 802         /* The node changed heartbeat generations. We assume this to
 803          * mean it dropped off but came back before we timed out. We
 804          * want to consider it down for the time being but don't want
 805          * to lose any changed_samples state we might build up to
 806          * considering it live again. */
 807         if (slot->ds_last_generation != le64_to_cpu(hb_block->hb_generation)) {
 808                 gen_changed = 1;
 809                 slot->ds_equal_samples = 0;
 810                 mlog(ML_HEARTBEAT, "Node %d changed generation (0x%llx "
 811                      "to 0x%llx)\n", slot->ds_node_num,
 812                      (long long)slot->ds_last_generation,
 813                      (long long)le64_to_cpu(hb_block->hb_generation));
 814         }
 815
 816         slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation);
 817
 818         mlog(ML_HEARTBEAT, "Slot %d gen 0x%llx cksum 0x%x "
 819              "seq %llu last %llu changed %u equal %u\n",
 820              slot->ds_node_num, (long long)slot->ds_last_generation,
 821              le32_to_cpu(hb_block->hb_cksum),
 822              (unsigned long long)le64_to_cpu(hb_block->hb_seq),
 823              (unsigned long long)slot->ds_last_time, slot->ds_changed_samples,
 824              slot->ds_equal_samples);
 825
 826         spin_lock(&o2hb_live_lock);
 827
 828 fire_callbacks:
 829         /* dead nodes only come to life after some number of
 830          * changes at any time during their dead time */
 831         if (list_empty(&slot->ds_live_item) &&
 832             slot->ds_changed_samples >= O2HB_LIVE_THRESHOLD) {
 833                 mlog(ML_HEARTBEAT, "Node %d (id 0x%llx) joined my region\n",
 834                      slot->ds_node_num, (long long)slot->ds_last_generation);
 835
 836                 set_bit(slot->ds_node_num, reg->hr_live_node_bitmap);
 837
 838                 /* first on the list generates a callback */
 839                 if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
 840                         mlog(ML_HEARTBEAT, "o2hb: Add node %d to live nodes "
 841                              "bitmap\n", slot->ds_node_num);
 842                         set_bit(slot->ds_node_num, o2hb_live_node_bitmap);
 843
 844                         o2hb_queue_node_event(&event, O2HB_NODE_UP_CB, node,
 845                                               slot->ds_node_num);
 846
 847                         changed = 1;
 848                 }
 849
 850                 list_add_tail(&slot->ds_live_item,
 851                               &o2hb_live_slots[slot->ds_node_num]);
 852
 853                 slot->ds_equal_samples = 0;
 854
 855                 /* We want to be sure that all nodes agree on the
 856                  * number of milliseconds before a node will be
 857                  * considered dead. The self-fencing timeout is
 858                  * computed from this value, and a discrepancy might
 859                  * result in heartbeat calling a node dead when it
 860                  * hasn't self-fenced yet. */
 861                 slot_dead_ms = le32_to_cpu(hb_block->hb_dead_ms);
 862                 if (slot_dead_ms && slot_dead_ms != dead_ms) {
 863                         /* TODO: Perhaps we can fail the region here. */
 864                         mlog(ML_ERROR, "Node %d on device %s has a dead count "
 865                              "of %u ms, but our count is %u ms.\n"
 866                              "Please double check your configuration values "
 867                              "for 'O2CB_HEARTBEAT_THRESHOLD'\n",
 868                              slot->ds_node_num, reg->hr_dev_name, slot_dead_ms,
 869                              dead_ms);
 870                 }
 871                 goto out;
 872         }
 873
 874         /* if the list is dead, we're done.. */
 875         if (list_empty(&slot->ds_live_item))
 876                 goto out;
 877
 878         /* live nodes only go dead after enough consequtive missed
 879          * samples..  reset the missed counter whenever we see
 880          * activity */
 881         if (slot->ds_equal_samples >= o2hb_dead_threshold || gen_changed) {
 882                 mlog(ML_HEARTBEAT, "Node %d left my region\n",
 883                      slot->ds_node_num);
 884
 885                 clear_bit(slot->ds_node_num, reg->hr_live_node_bitmap);
 886
 887                 /* last off the live_slot generates a callback */
 888                 list_del_init(&slot->ds_live_item);
 889                 if (list_empty(&o2hb_live_slots[slot->ds_node_num])) {
 890                         mlog(ML_HEARTBEAT, "o2hb: Remove node %d from live "
 891                              "nodes bitmap\n", slot->ds_node_num);
 892                         clear_bit(slot->ds_node_num, o2hb_live_node_bitmap);
 893
 894                         /* node can be null */
 895                         o2hb_queue_node_event(&event, O2HB_NODE_DOWN_CB,
 896                                               node, slot->ds_node_num);
 897
 898                         changed = 1;
 899                 }
 900
 901                 /* We don't clear this because the node is still
 902                  * actually writing new blocks. */
 903                 if (!gen_changed)
 904                         slot->ds_changed_samples = 0;
 905                 goto out;
 906         }
 907         if (slot->ds_changed_samples) {
 908                 slot->ds_changed_samples = 0;
 909                 slot->ds_equal_samples = 0;
 910         }
 911 out:
 912         o2hb_set_quorum_device(reg, slot);
 913
 914         spin_unlock(&o2hb_live_lock);
 915
 916         o2hb_run_event_list(&event);
 917
 918         if (node)
 919                 o2nm_node_put(node);
 920         return changed;
 921 }
 922
 923 /* This could be faster if we just implmented a find_last_bit, but I
 924  * don't think the circumstances warrant it. */
 925 static int o2hb_highest_node(unsigned long *nodes,
 926                              int numbits)
 927 {
 928         int highest, node;
 929
 930         highest = numbits;
 931         node = -1;
 932         while ((node = find_next_bit(nodes, numbits, node + 1)) != -1) {
 933                 if (node >= numbits)
 934                         break;
 935
 936                 highest = node;
 937         }
 938
 939         return highest;
 940 }
 941
 942 static int o2hb_do_disk_heartbeat(struct o2hb_region *reg)
 943 {
 944         int i, ret, highest_node, change = 0;
 945         unsigned long configured_nodes[BITS_TO_LONGS(O2NM_MAX_NODES)];
 946         unsigned long live_node_bitmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
 947         struct o2hb_bio_wait_ctxt write_wc;
 948
 949         ret = o2nm_configured_node_map(configured_nodes,
 950                                        sizeof(configured_nodes));
 951         if (ret) {
 952                 mlog_errno(ret);
 953                 return ret;
 954         }
 955
 956         /*
 957          * If a node is not configured but is in the livemap, we still need
 958          * to read the slot so as to be able to remove it from the livemap.
 959          */
 960         o2hb_fill_node_map(live_node_bitmap, sizeof(live_node_bitmap));
 961         i = -1;
 962         while ((i = find_next_bit(live_node_bitmap,
 963                                   O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
 964                 set_bit(i, configured_nodes);
 965         }
 966
 967         highest_node = o2hb_highest_node(configured_nodes, O2NM_MAX_NODES);
 968         if (highest_node >= O2NM_MAX_NODES) {
 969                 mlog(ML_NOTICE, "ocfs2_heartbeat: no configured nodes found!\n");
 970                 return -EINVAL;
 971         }
 972
 973         /* No sense in reading the slots of nodes that don't exist
 974          * yet. Of course, if the node definitions have holes in them
 975          * then we're reading an empty slot anyway... Consider this
 976          * best-effort. */
 977         ret = o2hb_read_slots(reg, highest_node + 1);
 978         if (ret < 0) {
 979                 mlog_errno(ret);
 980                 return ret;
 981         }
 982
 983         /* With an up to date view of the slots, we can check that no
 984          * other node has been improperly configured to heartbeat in
 985          * our slot. */
 986         if (!o2hb_check_last_timestamp(reg))
 987                 mlog(ML_ERROR, "Device \"%s\": another node is heartbeating "
 988                      "in our slot!\n", reg->hr_dev_name);
 989
 990         /* fill in the proper info for our next heartbeat */
 991         o2hb_prepare_block(reg, reg->hr_generation);
 992
 993         /* And fire off the write. Note that we don't wait on this I/O
 994          * until later. */
 995         ret = o2hb_issue_node_write(reg, &write_wc);
 996         if (ret < 0) {
 997                 mlog_errno(ret);
 998                 return ret;
 999         }
1000
1001         i = -1;
1002         while((i = find_next_bit(configured_nodes, O2NM_MAX_NODES, i + 1)) < O2NM_MAX_NODES) {
1003
1004                 change |= o2hb_check_slot(reg, &reg->hr_slots[i]);
1005         }
1006
1007         /*
1008          * We have to be sure we've advertised ourselves on disk
1009          * before we can go to steady state.  This ensures that
1010          * people we find in our steady state have seen us.
1011          */
1012         o2hb_wait_on_io(reg, &write_wc);
1013         if (write_wc.wc_error) {
1014                 /* Do not re-arm the write timeout on I/O error - we
1015                  * can't be sure that the new block ever made it to
1016                  * disk */
1017                 mlog(ML_ERROR, "Write error %d on device \"%s\"\n",
1018                      write_wc.wc_error, reg->hr_dev_name);
1019                 return write_wc.wc_error;
1020         }
1021
1022         o2hb_arm_write_timeout(reg);
1023
1024         /* let the person who launched us know when things are steady */
1025         if (!change && (atomic_read(&reg->hr_steady_iterations) != 0)) {
1026                 if (atomic_dec_and_test(&reg->hr_steady_iterations))
1027                         wake_up(&o2hb_steady_queue);
1028         }
1029
1030         return 0;
1031 }
1032
1033 /* Subtract b from a, storing the result in a. a *must* have a larger
1034  * value than b. */
1035 static void o2hb_tv_subtract(struct timeval *a,
1036                              struct timeval *b)
1037 {
1038         /* just return 0 when a is after b */
1039         if (a->tv_sec < b->tv_sec ||
1040             (a->tv_sec == b->tv_sec && a->tv_usec < b->tv_usec)) {
1041                 a->tv_sec = 0;
1042                 a->tv_usec = 0;
1043                 return;
1044         }
1045
1046         a->tv_sec -= b->tv_sec;
1047         a->tv_usec -= b->tv_usec;
1048         while ( a->tv_usec < 0 ) {
1049                 a->tv_sec--;
1050                 a->tv_usec += 1000000;
1051         }
1052 }
1053
1054 static unsigned int o2hb_elapsed_msecs(struct timeval *start,
1055                                        struct timeval *end)
1056 {
1057         struct timeval res = *end;
1058
1059         o2hb_tv_subtract(&res, start);
1060
1061         return res.tv_sec * 1000 + res.tv_usec / 1000;
1062 }
1063
1064 /*
1065  * we ride the region ref that the region dir holds.  before the region
1066  * dir is removed and drops it ref it will wait to tear down this
1067  * thread.
1068  */
1069 static int o2hb_thread(void *data)
1070 {
1071         int i, ret;
1072         struct o2hb_region *reg = data;
1073         struct o2hb_bio_wait_ctxt write_wc;
1074         struct timeval before_hb, after_hb;
1075         unsigned int elapsed_msec;
1076
1077         mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread running\n");
1078
1079         set_user_nice(current, -20);
1080
1081         /* Pin node */
1082         o2nm_depend_this_node();
1083
1084         while (!kthread_should_stop() && !reg->hr_unclean_stop) {
1085                 /* We track the time spent inside
1086                  * o2hb_do_disk_heartbeat so that we avoid more than
1087                  * hr_timeout_ms between disk writes. On busy systems
1088                  * this should result in a heartbeat which is less
1089                  * likely to time itself out. */
1090                 do_gettimeofday(&before_hb);
1091
1092                 i = 0;
1093                 do {
1094                         ret = o2hb_do_disk_heartbeat(reg);
1095                 } while (ret && ++i < 2);
1096
1097                 do_gettimeofday(&after_hb);
1098                 elapsed_msec = o2hb_elapsed_msecs(&before_hb, &after_hb);
1099
1100                 mlog(ML_HEARTBEAT,
1101                      "start = %lu.%lu, end = %lu.%lu, msec = %u\n",
1102                      before_hb.tv_sec, (unsigned long) before_hb.tv_usec,
1103                      after_hb.tv_sec, (unsigned long) after_hb.tv_usec,
1104                      elapsed_msec);
1105
1106                 if (elapsed_msec < reg->hr_timeout_ms) {
1107                         /* the kthread api has blocked signals for us so no
1108                          * need to record the return value. */
1109                         msleep_interruptible(reg->hr_timeout_ms - elapsed_msec);
1110                 }
1111         }
1112
1113         o2hb_disarm_write_timeout(reg);
1114
1115         /* unclean stop is only used in very bad situation */
1116         for(i = 0; !reg->hr_unclean_stop && i < reg->hr_blocks; i++)
1117                 o2hb_shutdown_slot(&reg->hr_slots[i]);
1118
1119         /* Explicit down notification - avoid forcing the other nodes
1120          * to timeout on this region when we could just as easily
1121          * write a clear generation - thus indicating to them that
1122          * this node has left this region.
1123          *
1124          * XXX: Should we skip this on unclean_stop? */
1125         o2hb_prepare_block(reg, 0);
1126         ret = o2hb_issue_node_write(reg, &write_wc);
1127         if (ret == 0) {
1128                 o2hb_wait_on_io(reg, &write_wc);
1129         } else {
1130                 mlog_errno(ret);
1131         }
1132
1133         /* Unpin node */
1134         o2nm_undepend_this_node();
1135
1136         mlog(ML_HEARTBEAT|ML_KTHREAD, "hb thread exiting\n");
1137
1138         return 0;
1139 }
1140
1141 #ifdef CONFIG_DEBUG_FS
1142 static int o2hb_debug_open(struct inode *inode, struct file *file)
1143 {
1144         struct o2hb_debug_buf *db = inode->i_private;
1145         struct o2hb_region *reg;
1146         unsigned long map[BITS_TO_LONGS(O2NM_MAX_NODES)];
1147         char *buf = NULL;
1148         int i = -1;
1149         int out = 0;
1150
1151         /* max_nodes should be the largest bitmap we pass here */
1152         BUG_ON(sizeof(map) < db->db_size);
1153
1154         buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
1155         if (!buf)
1156                 goto bail;
1157
1158         switch (db->db_type) {
1159         case O2HB_DB_TYPE_LIVENODES:
1160         case O2HB_DB_TYPE_LIVEREGIONS:
1161         case O2HB_DB_TYPE_QUORUMREGIONS:
1162         case O2HB_DB_TYPE_FAILEDREGIONS:
1163                 spin_lock(&o2hb_live_lock);
1164                 memcpy(map, db->db_data, db->db_size);
1165                 spin_unlock(&o2hb_live_lock);
1166                 break;
1167
1168         case O2HB_DB_TYPE_REGION_LIVENODES:
1169                 spin_lock(&o2hb_live_lock);
1170                 reg = (struct o2hb_region *)db->db_data;
1171                 memcpy(map, reg->hr_live_node_bitmap, db->db_size);
1172                 spin_unlock(&o2hb_live_lock);
1173                 break;
1174
1175         case O2HB_DB_TYPE_REGION_NUMBER:
1176                 reg = (struct o2hb_region *)db->db_data;
1177                 out += snprintf(buf + out, PAGE_SIZE - out, "%d\n",
1178                                 reg->hr_region_num);
1179                 goto done;
1180
1181         case O2HB_DB_TYPE_REGION_ELAPSED_TIME:
1182                 reg = (struct o2hb_region *)db->db_data;
1183                 out += snprintf(buf + out, PAGE_SIZE - out, "%u\n",
1184                                 jiffies_to_msecs(jiffies -
1185                                                  reg->hr_last_timeout_start));
1186                 goto done;
1187
1188         case O2HB_DB_TYPE_REGION_PINNED:
1189                 reg = (struct o2hb_region *)db->db_data;
1190                 out += snprintf(buf + out, PAGE_SIZE - out, "%u\n",
1191                                 !!reg->hr_item_pinned);
1192                 goto done;
1193
1194         default:
1195                 goto done;
1196         }
1197
1198         while ((i = find_next_bit(map, db->db_len, i + 1)) < db->db_len)
1199                 out += snprintf(buf + out, PAGE_SIZE - out, "%d ", i);
1200         out += snprintf(buf + out, PAGE_SIZE - out, "\n");
1201
1202 done:
1203         i_size_write(inode, out);
1204
1205         file->private_data = buf;
1206
1207         return 0;
1208 bail:
1209         return -ENOMEM;
1210 }
1211
1212 static int o2hb_debug_release(struct inode *inode, struct file *file)
1213 {
1214         kfree(file->private_data);
1215         return 0;
1216 }
1217
1218 static ssize_t o2hb_debug_read(struct file *file, char __user *buf,
1219                                  size_t nbytes, loff_t *ppos)
1220 {
1221         return simple_read_from_buffer(buf, nbytes, ppos, file->private_data,
1222                                        i_size_read(file->f_mapping->host));
1223 }
1224 #else
1225 static int o2hb_debug_open(struct inode *inode, struct file *file)
1226 {
1227         return 0;
1228 }
1229 static int o2hb_debug_release(struct inode *inode, struct file *file)
1230 {
1231         return 0;
1232 }
1233 static ssize_t o2hb_debug_read(struct file *file, char __user *buf,
1234                                size_t nbytes, loff_t *ppos)
1235 {
1236         return 0;
1237 }
1238 #endif  /* CONFIG_DEBUG_FS */
1239
1240 static const struct file_operations o2hb_debug_fops = {
1241         .open =         o2hb_debug_open,
1242         .release =      o2hb_debug_release,
1243         .read =         o2hb_debug_read,
1244         .llseek =       generic_file_llseek,
1245 };
1246
1247 void o2hb_exit(void)
1248 {
1249         kfree(o2hb_db_livenodes);
1250         kfree(o2hb_db_liveregions);
1251         kfree(o2hb_db_quorumregions);
1252         kfree(o2hb_db_failedregions);
1253         debugfs_remove(o2hb_debug_failedregions);
1254         debugfs_remove(o2hb_debug_quorumregions);
1255         debugfs_remove(o2hb_debug_liveregions);
1256         debugfs_remove(o2hb_debug_livenodes);
1257         debugfs_remove(o2hb_debug_dir);
1258 }
1259
1260 static struct dentry *o2hb_debug_create(const char *name, struct dentry *dir,
1261                                         struct o2hb_debug_buf **db, int db_len,
1262                                         int type, int size, int len, void *data)
1263 {
1264         *db = kmalloc(db_len, GFP_KERNEL);
1265         if (!*db)
1266                 return NULL;
1267
1268         (*db)->db_type = type;
1269         (*db)->db_size = size;
1270         (*db)->db_len = len;
1271         (*db)->db_data = data;
1272
1273         return debugfs_create_file(name, S_IFREG|S_IRUSR, dir, *db,
1274                                    &o2hb_debug_fops);
1275 }
1276
1277 static int o2hb_debug_init(void)
1278 {
1279         int ret = -ENOMEM;
1280
1281         o2hb_debug_dir = debugfs_create_dir(O2HB_DEBUG_DIR, NULL);
1282         if (!o2hb_debug_dir) {
1283                 mlog_errno(ret);
1284                 goto bail;
1285         }
1286
1287         o2hb_debug_livenodes = o2hb_debug_create(O2HB_DEBUG_LIVENODES,
1288                                                  o2hb_debug_dir,
1289                                                  &o2hb_db_livenodes,
1290                                                  sizeof(*o2hb_db_livenodes),
1291                                                  O2HB_DB_TYPE_LIVENODES,
1292                                                  sizeof(o2hb_live_node_bitmap),
1293                                                  O2NM_MAX_NODES,
1294                                                  o2hb_live_node_bitmap);
1295         if (!o2hb_debug_livenodes) {
1296                 mlog_errno(ret);
1297                 goto bail;
1298         }
1299
1300         o2hb_debug_liveregions = o2hb_debug_create(O2HB_DEBUG_LIVEREGIONS,
1301                                                    o2hb_debug_dir,
1302                                                    &o2hb_db_liveregions,
1303                                                    sizeof(*o2hb_db_liveregions),
1304                                                    O2HB_DB_TYPE_LIVEREGIONS,
1305                                                    sizeof(o2hb_live_region_bitmap),
1306                                                    O2NM_MAX_REGIONS,
1307                                                    o2hb_live_region_bitmap);
1308         if (!o2hb_debug_liveregions) {
1309                 mlog_errno(ret);
1310                 goto bail;
1311         }
1312
1313         o2hb_debug_quorumregions =
1314                         o2hb_debug_create(O2HB_DEBUG_QUORUMREGIONS,
1315                                           o2hb_debug_dir,
1316                                           &o2hb_db_quorumregions,
1317                                           sizeof(*o2hb_db_quorumregions),
1318                                           O2HB_DB_TYPE_QUORUMREGIONS,
1319                                           sizeof(o2hb_quorum_region_bitmap),
1320                                           O2NM_MAX_REGIONS,
1321                                           o2hb_quorum_region_bitmap);
1322         if (!o2hb_debug_quorumregions) {
1323                 mlog_errno(ret);
1324                 goto bail;
1325         }
1326
1327         o2hb_debug_failedregions =
1328                         o2hb_debug_create(O2HB_DEBUG_FAILEDREGIONS,
1329                                           o2hb_debug_dir,
1330                                           &o2hb_db_failedregions,
1331                                           sizeof(*o2hb_db_failedregions),
1332                                           O2HB_DB_TYPE_FAILEDREGIONS,
1333                                           sizeof(o2hb_failed_region_bitmap),
1334                                           O2NM_MAX_REGIONS,
1335                                           o2hb_failed_region_bitmap);
1336         if (!o2hb_debug_failedregions) {
1337                 mlog_errno(ret);
1338                 goto bail;
1339         }
1340
1341         ret = 0;
1342 bail:
1343         if (ret)
1344                 o2hb_exit();
1345
1346         return ret;
1347 }
1348
1349 int o2hb_init(void)
1350 {
1351         int i;
1352
1353         for (i = 0; i < ARRAY_SIZE(o2hb_callbacks); i++)
1354                 INIT_LIST_HEAD(&o2hb_callbacks[i].list);
1355
1356         for (i = 0; i < ARRAY_SIZE(o2hb_live_slots); i++)
1357                 INIT_LIST_HEAD(&o2hb_live_slots[i]);
1358
1359         INIT_LIST_HEAD(&o2hb_node_events);
1360
1361         memset(o2hb_live_node_bitmap, 0, sizeof(o2hb_live_node_bitmap));
1362         memset(o2hb_region_bitmap, 0, sizeof(o2hb_region_bitmap));
1363         memset(o2hb_live_region_bitmap, 0, sizeof(o2hb_live_region_bitmap));
1364         memset(o2hb_quorum_region_bitmap, 0, sizeof(o2hb_quorum_region_bitmap));
1365         memset(o2hb_failed_region_bitmap, 0, sizeof(o2hb_failed_region_bitmap));
1366
1367         o2hb_dependent_users = 0;
1368
1369         return o2hb_debug_init();
1370 }
1371
1372 /* if we're already in a callback then we're already serialized by the sem */
1373 static void o2hb_fill_node_map_from_callback(unsigned long *map,
1374                                              unsigned bytes)
1375 {
1376         BUG_ON(bytes < (BITS_TO_LONGS(O2NM_MAX_NODES) * sizeof(unsigned long)));
1377
1378         memcpy(map, &o2hb_live_node_bitmap, bytes);
1379 }
1380
1381 /*
1382  * get a map of all nodes that are heartbeating in any regions
1383  */
1384 void o2hb_fill_node_map(unsigned long *map, unsigned bytes)
1385 {
1386         /* callers want to serialize this map and callbacks so that they
1387          * can trust that they don't miss nodes coming to the party */
1388         down_read(&o2hb_callback_sem);
1389         spin_lock(&o2hb_live_lock);
1390         o2hb_fill_node_map_from_callback(map, bytes);
1391         spin_unlock(&o2hb_live_lock);
1392         up_read(&o2hb_callback_sem);
1393 }
1394 EXPORT_SYMBOL_GPL(o2hb_fill_node_map);
1395
1396 /*
1397  * heartbeat configfs bits.  The heartbeat set is a default set under
1398  * the cluster set in nodemanager.c.
1399  */
1400
1401 static struct o2hb_region *to_o2hb_region(struct config_item *item)
1402 {
1403         return item ? container_of(item, struct o2hb_region, hr_item) : NULL;
1404 }
1405
1406 /* drop_item only drops its ref after killing the thread, nothing should
1407  * be using the region anymore.  this has to clean up any state that
1408  * attributes might have built up. */
1409 static void o2hb_region_release(struct config_item *item)
1410 {
1411         int i;
1412         struct page *page;
1413         struct o2hb_region *reg = to_o2hb_region(item);
1414
1415         if (reg->hr_tmp_block)
1416                 kfree(reg->hr_tmp_block);
1417
1418         if (reg->hr_slot_data) {
1419                 for (i = 0; i < reg->hr_num_pages; i++) {
1420                         page = reg->hr_slot_data[i];
1421                         if (page)
1422                                 __free_page(page);
1423                 }
1424                 kfree(reg->hr_slot_data);
1425         }
1426
1427         if (reg->hr_bdev)
1428                 blkdev_put(reg->hr_bdev, FMODE_READ|FMODE_WRITE);
1429
1430         if (reg->hr_slots)
1431                 kfree(reg->hr_slots);
1432
1433         kfree(reg->hr_db_regnum);
1434         kfree(reg->hr_db_livenodes);
1435         debugfs_remove(reg->hr_debug_livenodes);
1436         debugfs_remove(reg->hr_debug_regnum);
1437         debugfs_remove(reg->hr_debug_elapsed_time);
1438         debugfs_remove(reg->hr_debug_pinned);
1439         debugfs_remove(reg->hr_debug_dir);
1440
1441         spin_lock(&o2hb_live_lock);
1442         list_del(&reg->hr_all_item);
1443         spin_unlock(&o2hb_live_lock);
1444
1445         kfree(reg);
1446 }
1447
1448 static int o2hb_read_block_input(struct o2hb_region *reg,
1449                                  const char *page,
1450                                  size_t count,
1451                                  unsigned long *ret_bytes,
1452                                  unsigned int *ret_bits)
1453 {
1454         unsigned long bytes;
1455         char *p = (char *)page;
1456
1457         bytes = simple_strtoul(p, &p, 0);
1458         if (!p || (*p && (*p != '\n')))
1459                 return -EINVAL;
1460
1461         /* Heartbeat and fs min / max block sizes are the same. */
1462         if (bytes > 4096 || bytes < 512)
1463                 return -ERANGE;
1464         if (hweight16(bytes) != 1)
1465                 return -EINVAL;
1466
1467         if (ret_bytes)
1468                 *ret_bytes = bytes;
1469         if (ret_bits)
1470                 *ret_bits = ffs(bytes) - 1;
1471
1472         return 0;
1473 }
1474
1475 static ssize_t o2hb_region_block_bytes_read(struct o2hb_region *reg,
1476                                             char *page)
1477 {
1478         return sprintf(page, "%u\n", reg->hr_block_bytes);
1479 }
1480
1481 static ssize_t o2hb_region_block_bytes_write(struct o2hb_region *reg,
1482                                              const char *page,
1483                                              size_t count)
1484 {
1485         int status;
1486         unsigned long block_bytes;
1487         unsigned int block_bits;
1488
1489         if (reg->hr_bdev)
1490                 return -EINVAL;
1491
1492         status = o2hb_read_block_input(reg, page, count,
1493                                        &block_bytes, &block_bits);
1494         if (status)
1495                 return status;
1496
1497         reg->hr_block_bytes = (unsigned int)block_bytes;
1498         reg->hr_block_bits = block_bits;
1499
1500         return count;
1501 }
1502
1503 static ssize_t o2hb_region_start_block_read(struct o2hb_region *reg,
1504                                             char *page)
1505 {
1506         return sprintf(page, "%llu\n", reg->hr_start_block);
1507 }
1508
1509 static ssize_t o2hb_region_start_block_write(struct o2hb_region *reg,
1510                                              const char *page,
1511                                              size_t count)
1512 {
1513         unsigned long long tmp;
1514         char *p = (char *)page;
1515
1516         if (reg->hr_bdev)
1517                 return -EINVAL;
1518
1519         tmp = simple_strtoull(p, &p, 0);
1520         if (!p || (*p && (*p != '\n')))
1521                 return -EINVAL;
1522
1523         reg->hr_start_block = tmp;
1524
1525         return count;
1526 }
1527
1528 static ssize_t o2hb_region_blocks_read(struct o2hb_region *reg,
1529                                        char *page)
1530 {
1531         return sprintf(page, "%d\n", reg->hr_blocks);
1532 }
1533
1534 static ssize_t o2hb_region_blocks_write(struct o2hb_region *reg,
1535                                         const char *page,
1536                                         size_t count)
1537 {
1538         unsigned long tmp;
1539         char *p = (char *)page;
1540
1541         if (reg->hr_bdev)
1542                 return -EINVAL;
1543
1544         tmp = simple_strtoul(p, &p, 0);
1545         if (!p || (*p && (*p != '\n')))
1546                 return -EINVAL;
1547
1548         if (tmp > O2NM_MAX_NODES || tmp == 0)
1549                 return -ERANGE;
1550
1551         reg->hr_blocks = (unsigned int)tmp;
1552
1553         return count;
1554 }
1555
1556 static ssize_t o2hb_region_dev_read(struct o2hb_region *reg,
1557                                     char *page)
1558 {
1559         unsigned int ret = 0;
1560
1561         if (reg->hr_bdev)
1562                 ret = sprintf(page, "%s\n", reg->hr_dev_name);
1563
1564         return ret;
1565 }
1566
1567 static void o2hb_init_region_params(struct o2hb_region *reg)
1568 {
1569         reg->hr_slots_per_page = PAGE_CACHE_SIZE >> reg->hr_block_bits;
1570         reg->hr_timeout_ms = O2HB_REGION_TIMEOUT_MS;
1571
1572         mlog(ML_HEARTBEAT, "hr_start_block = %llu, hr_blocks = %u\n",
1573              reg->hr_start_block, reg->hr_blocks);
1574         mlog(ML_HEARTBEAT, "hr_block_bytes = %u, hr_block_bits = %u\n",
1575              reg->hr_block_bytes, reg->hr_block_bits);
1576         mlog(ML_HEARTBEAT, "hr_timeout_ms = %u\n", reg->hr_timeout_ms);
1577         mlog(ML_HEARTBEAT, "dead threshold = %u\n", o2hb_dead_threshold);
1578 }
1579
1580 static int o2hb_map_slot_data(struct o2hb_region *reg)
1581 {
1582         int i, j;
1583         unsigned int last_slot;
1584         unsigned int spp = reg->hr_slots_per_page;
1585         struct page *page;
1586         char *raw;
1587         struct o2hb_disk_slot *slot;
1588
1589         reg->hr_tmp_block = kmalloc(reg->hr_block_bytes, GFP_KERNEL);
1590         if (reg->hr_tmp_block == NULL) {
1591                 mlog_errno(-ENOMEM);
1592                 return -ENOMEM;
1593         }
1594
1595         reg->hr_slots = kcalloc(reg->hr_blocks,
1596                                 sizeof(struct o2hb_disk_slot), GFP_KERNEL);
1597         if (reg->hr_slots == NULL) {
1598                 mlog_errno(-ENOMEM);
1599                 return -ENOMEM;
1600         }
1601
1602         for(i = 0; i < reg->hr_blocks; i++) {
1603                 slot = &reg->hr_slots[i];
1604                 slot->ds_node_num = i;
1605                 INIT_LIST_HEAD(&slot->ds_live_item);
1606                 slot->ds_raw_block = NULL;
1607         }
1608
1609         reg->hr_num_pages = (reg->hr_blocks + spp - 1) / spp;
1610         mlog(ML_HEARTBEAT, "Going to require %u pages to cover %u blocks "
1611                            "at %u blocks per page\n",
1612              reg->hr_num_pages, reg->hr_blocks, spp);
1613
1614         reg->hr_slot_data = kcalloc(reg->hr_num_pages, sizeof(struct page *),
1615                                     GFP_KERNEL);
1616         if (!reg->hr_slot_data) {
1617                 mlog_errno(-ENOMEM);
1618                 return -ENOMEM;
1619         }
1620
1621         for(i = 0; i < reg->hr_num_pages; i++) {
1622                 page = alloc_page(GFP_KERNEL);
1623                 if (!page) {
1624                         mlog_errno(-ENOMEM);
1625                         return -ENOMEM;
1626                 }
1627
1628                 reg->hr_slot_data[i] = page;
1629
1630                 last_slot = i * spp;
1631                 raw = page_address(page);
1632                 for (j = 0;
1633                      (j < spp) && ((j + last_slot) < reg->hr_blocks);
1634                      j++) {
1635                         BUG_ON((j + last_slot) >= reg->hr_blocks);
1636
1637                         slot = &reg->hr_slots[j + last_slot];
1638                         slot->ds_raw_block =
1639                                 (struct o2hb_disk_heartbeat_block *) raw;
1640
1641                         raw += reg->hr_block_bytes;
1642                 }
1643         }
1644
1645         return 0;
1646 }
1647
1648 /* Read in all the slots available and populate the tracking
1649  * structures so that we can start with a baseline idea of what's
1650  * there. */
1651 static int o2hb_populate_slot_data(struct o2hb_region *reg)
1652 {
1653         int ret, i;
1654         struct o2hb_disk_slot *slot;
1655         struct o2hb_disk_heartbeat_block *hb_block;
1656
1657         mlog_entry_void();
1658
1659         ret = o2hb_read_slots(reg, reg->hr_blocks);
1660         if (ret) {
1661                 mlog_errno(ret);
1662                 goto out;
1663         }
1664
1665         /* We only want to get an idea of the values initially in each
1666          * slot, so we do no verification - o2hb_check_slot will
1667          * actually determine if each configured slot is valid and
1668          * whether any values have changed. */
1669         for(i = 0; i < reg->hr_blocks; i++) {
1670                 slot = &reg->hr_slots[i];
1671                 hb_block = (struct o2hb_disk_heartbeat_block *) slot->ds_raw_block;
1672
1673                 /* Only fill the values that o2hb_check_slot uses to
1674                  * determine changing slots */
1675                 slot->ds_last_time = le64_to_cpu(hb_block->hb_seq);
1676                 slot->ds_last_generation = le64_to_cpu(hb_block->hb_generation);
1677         }
1678
1679 out:
1680         mlog_exit(ret);
1681         return ret;
1682 }
1683
1684 /* this is acting as commit; we set up all of hr_bdev and hr_task or nothing */
1685 static ssize_t o2hb_region_dev_write(struct o2hb_region *reg,
1686                                      const char *page,
1687                                      size_t count)
1688 {
1689         struct task_struct *hb_task;
1690         long fd;
1691         int sectsize;
1692         char *p = (char *)page;
1693         struct file *filp = NULL;
1694         struct inode *inode = NULL;
1695         ssize_t ret = -EINVAL;
1696
1697         if (reg->hr_bdev)
1698                 goto out;
1699
1700         /* We can't heartbeat without having had our node number
1701          * configured yet. */
1702         if (o2nm_this_node() == O2NM_MAX_NODES)
1703                 goto out;
1704
1705         fd = simple_strtol(p, &p, 0);
1706         if (!p || (*p && (*p != '\n')))
1707                 goto out;
1708
1709         if (fd < 0 || fd >= INT_MAX)
1710                 goto out;
1711
1712         filp = fget(fd);
1713         if (filp == NULL)
1714                 goto out;
1715
1716         if (reg->hr_blocks == 0 || reg->hr_start_block == 0 ||
1717             reg->hr_block_bytes == 0)
1718                 goto out;
1719
1720         inode = igrab(filp->f_mapping->host);
1721         if (inode == NULL)
1722                 goto out;
1723
1724         if (!S_ISBLK(inode->i_mode))
1725                 goto out;
1726
1727         reg->hr_bdev = I_BDEV(filp->f_mapping->host);
1728         ret = blkdev_get(reg->hr_bdev, FMODE_WRITE | FMODE_READ, NULL);
1729         if (ret) {
1730                 reg->hr_bdev = NULL;
1731                 goto out;
1732         }
1733         inode = NULL;
1734
1735         bdevname(reg->hr_bdev, reg->hr_dev_name);
1736
1737         sectsize = bdev_logical_block_size(reg->hr_bdev);
1738         if (sectsize != reg->hr_block_bytes) {
1739                 mlog(ML_ERROR,
1740                      "blocksize %u incorrect for device, expected %d",
1741                      reg->hr_block_bytes, sectsize);
1742                 ret = -EINVAL;
1743                 goto out;
1744         }
1745
1746         o2hb_init_region_params(reg);
1747
1748         /* Generation of zero is invalid */
1749         do {
1750                 get_random_bytes(&reg->hr_generation,
1751                                  sizeof(reg->hr_generation));
1752         } while (reg->hr_generation == 0);
1753
1754         ret = o2hb_map_slot_data(reg);
1755         if (ret) {
1756                 mlog_errno(ret);
1757                 goto out;
1758         }
1759
1760         ret = o2hb_populate_slot_data(reg);
1761         if (ret) {
1762                 mlog_errno(ret);
1763                 goto out;
1764         }
1765
1766         INIT_DELAYED_WORK(&reg->hr_write_timeout_work, o2hb_write_timeout);
1767
1768         /*
1769          * A node is considered live after it has beat LIVE_THRESHOLD
1770          * times.  We're not steady until we've given them a chance
1771          * _after_ our first read.
1772          */
1773         atomic_set(&reg->hr_steady_iterations, O2HB_LIVE_THRESHOLD + 1);
1774
1775         hb_task = kthread_run(o2hb_thread, reg, "o2hb-%s",
1776                               reg->hr_item.ci_name);
1777         if (IS_ERR(hb_task)) {
1778                 ret = PTR_ERR(hb_task);
1779                 mlog_errno(ret);
1780                 goto out;
1781         }
1782
1783         spin_lock(&o2hb_live_lock);
1784         reg->hr_task = hb_task;
1785         spin_unlock(&o2hb_live_lock);
1786
1787         ret = wait_event_interruptible(o2hb_steady_queue,
1788                                 atomic_read(&reg->hr_steady_iterations) == 0);
1789         if (ret) {
1790                 /* We got interrupted (hello ptrace!).  Clean up */
1791                 spin_lock(&o2hb_live_lock);
1792                 hb_task = reg->hr_task;
1793                 reg->hr_task = NULL;
1794                 spin_unlock(&o2hb_live_lock);
1795
1796                 if (hb_task)
1797                         kthread_stop(hb_task);
1798                 goto out;
1799         }
1800
1801         /* Ok, we were woken.  Make sure it wasn't by drop_item() */
1802         spin_lock(&o2hb_live_lock);
1803         hb_task = reg->hr_task;
1804         if (o2hb_global_heartbeat_active())
1805                 set_bit(reg->hr_region_num, o2hb_live_region_bitmap);
1806         spin_unlock(&o2hb_live_lock);
1807
1808         if (hb_task)
1809                 ret = count;
1810         else
1811                 ret = -EIO;
1812
1813         if (hb_task && o2hb_global_heartbeat_active())
1814                 printk(KERN_NOTICE "o2hb: Heartbeat started on region %s\n",
1815                        config_item_name(&reg->hr_item));
1816
1817 out:
1818         if (filp)
1819                 fput(filp);
1820         if (inode)
1821                 iput(inode);
1822         if (ret < 0) {
1823                 if (reg->hr_bdev) {
1824                         blkdev_put(reg->hr_bdev, FMODE_READ|FMODE_WRITE);
1825                         reg->hr_bdev = NULL;
1826                 }
1827         }
1828         return ret;
1829 }
1830
1831 static ssize_t o2hb_region_pid_read(struct o2hb_region *reg,
1832                                       char *page)
1833 {
1834         pid_t pid = 0;
1835
1836         spin_lock(&o2hb_live_lock);
1837         if (reg->hr_task)
1838                 pid = task_pid_nr(reg->hr_task);
1839         spin_unlock(&o2hb_live_lock);
1840
1841         if (!pid)
1842                 return 0;
1843
1844         return sprintf(page, "%u\n", pid);
1845 }
1846
1847 struct o2hb_region_attribute {
1848         struct configfs_attribute attr;
1849         ssize_t (*show)(struct o2hb_region *, char *);
1850         ssize_t (*store)(struct o2hb_region *, const char *, size_t);
1851 };
1852
1853 static struct o2hb_region_attribute o2hb_region_attr_block_bytes = {
1854         .attr   = { .ca_owner = THIS_MODULE,
1855                     .ca_name = "block_bytes",
1856                     .ca_mode = S_IRUGO | S_IWUSR },
1857         .show   = o2hb_region_block_bytes_read,
1858         .store  = o2hb_region_block_bytes_write,
1859 };
1860
1861 static struct o2hb_region_attribute o2hb_region_attr_start_block = {
1862         .attr   = { .ca_owner = THIS_MODULE,
1863                     .ca_name = "start_block",
1864                     .ca_mode = S_IRUGO | S_IWUSR },
1865         .show   = o2hb_region_start_block_read,
1866         .store  = o2hb_region_start_block_write,
1867 };
1868
1869 static struct o2hb_region_attribute o2hb_region_attr_blocks = {
1870         .attr   = { .ca_owner = THIS_MODULE,
1871                     .ca_name = "blocks",
1872                     .ca_mode = S_IRUGO | S_IWUSR },
1873         .show   = o2hb_region_blocks_read,
1874         .store  = o2hb_region_blocks_write,
1875 };
1876
1877 static struct o2hb_region_attribute o2hb_region_attr_dev = {
1878         .attr   = { .ca_owner = THIS_MODULE,
1879                     .ca_name = "dev",
1880                     .ca_mode = S_IRUGO | S_IWUSR },
1881         .show   = o2hb_region_dev_read,
1882         .store  = o2hb_region_dev_write,
1883 };
1884
1885 static struct o2hb_region_attribute o2hb_region_attr_pid = {
1886        .attr   = { .ca_owner = THIS_MODULE,
1887                    .ca_name = "pid",
1888                    .ca_mode = S_IRUGO | S_IRUSR },
1889        .show   = o2hb_region_pid_read,
1890 };
1891
1892 static struct configfs_attribute *o2hb_region_attrs[] = {
1893         &o2hb_region_attr_block_bytes.attr,
1894         &o2hb_region_attr_start_block.attr,
1895         &o2hb_region_attr_blocks.attr,
1896         &o2hb_region_attr_dev.attr,
1897         &o2hb_region_attr_pid.attr,
1898         NULL,
1899 };
1900
1901 static ssize_t o2hb_region_show(struct config_item *item,
1902                                 struct configfs_attribute *attr,
1903                                 char *page)
1904 {
1905         struct o2hb_region *reg = to_o2hb_region(item);
1906         struct o2hb_region_attribute *o2hb_region_attr =
1907                 container_of(attr, struct o2hb_region_attribute, attr);
1908         ssize_t ret = 0;
1909
1910         if (o2hb_region_attr->show)
1911                 ret = o2hb_region_attr->show(reg, page);
1912         return ret;
1913 }
1914
1915 static ssize_t o2hb_region_store(struct config_item *item,
1916                                  struct configfs_attribute *attr,
1917                                  const char *page, size_t count)
1918 {
1919         struct o2hb_region *reg = to_o2hb_region(item);
1920         struct o2hb_region_attribute *o2hb_region_attr =
1921                 container_of(attr, struct o2hb_region_attribute, attr);
1922         ssize_t ret = -EINVAL;
1923
1924         if (o2hb_region_attr->store)
1925                 ret = o2hb_region_attr->store(reg, page, count);
1926         return ret;
1927 }
1928
1929 static struct configfs_item_operations o2hb_region_item_ops = {
1930         .release                = o2hb_region_release,
1931         .show_attribute         = o2hb_region_show,
1932         .store_attribute        = o2hb_region_store,
1933 };
1934
1935 static struct config_item_type o2hb_region_type = {
1936         .ct_item_ops    = &o2hb_region_item_ops,
1937         .ct_attrs       = o2hb_region_attrs,
1938         .ct_owner       = THIS_MODULE,
1939 };
1940
1941 /* heartbeat set */
1942
1943 struct o2hb_heartbeat_group {
1944         struct config_group hs_group;
1945         /* some stuff? */
1946 };
1947
1948 static struct o2hb_heartbeat_group *to_o2hb_heartbeat_group(struct config_group *group)
1949 {
1950         return group ?
1951                 container_of(group, struct o2hb_heartbeat_group, hs_group)
1952                 : NULL;
1953 }
1954
1955 static int o2hb_debug_region_init(struct o2hb_region *reg, struct dentry *dir)
1956 {
1957         int ret = -ENOMEM;
1958
1959         reg->hr_debug_dir =
1960                 debugfs_create_dir(config_item_name(&reg->hr_item), dir);
1961         if (!reg->hr_debug_dir) {
1962                 mlog_errno(ret);
1963                 goto bail;
1964         }
1965
1966         reg->hr_debug_livenodes =
1967                         o2hb_debug_create(O2HB_DEBUG_LIVENODES,
1968                                           reg->hr_debug_dir,
1969                                           &(reg->hr_db_livenodes),
1970                                           sizeof(*(reg->hr_db_livenodes)),
1971                                           O2HB_DB_TYPE_REGION_LIVENODES,
1972                                           sizeof(reg->hr_live_node_bitmap),
1973                                           O2NM_MAX_NODES, reg);
1974         if (!reg->hr_debug_livenodes) {
1975                 mlog_errno(ret);
1976                 goto bail;
1977         }
1978
1979         reg->hr_debug_regnum =
1980                         o2hb_debug_create(O2HB_DEBUG_REGION_NUMBER,
1981                                           reg->hr_debug_dir,
1982                                           &(reg->hr_db_regnum),
1983                                           sizeof(*(reg->hr_db_regnum)),
1984                                           O2HB_DB_TYPE_REGION_NUMBER,
1985                                           0, O2NM_MAX_NODES, reg);
1986         if (!reg->hr_debug_regnum) {
1987                 mlog_errno(ret);
1988                 goto bail;
1989         }
1990
1991         reg->hr_debug_elapsed_time =
1992                         o2hb_debug_create(O2HB_DEBUG_REGION_ELAPSED_TIME,
1993                                           reg->hr_debug_dir,
1994                                           &(reg->hr_db_elapsed_time),
1995                                           sizeof(*(reg->hr_db_elapsed_time)),
1996                                           O2HB_DB_TYPE_REGION_ELAPSED_TIME,
1997                                           0, 0, reg);
1998         if (!reg->hr_debug_elapsed_time) {
1999                 mlog_errno(ret);
2000                 goto bail;
2001         }
2002
2003         reg->hr_debug_pinned =
2004                         o2hb_debug_create(O2HB_DEBUG_REGION_PINNED,
2005                                           reg->hr_debug_dir,
2006                                           &(reg->hr_db_pinned),
2007                                           sizeof(*(reg->hr_db_pinned)),
2008                                           O2HB_DB_TYPE_REGION_PINNED,
2009                                           0, 0, reg);
2010         if (!reg->hr_debug_pinned) {
2011                 mlog_errno(ret);
2012                 goto bail;
2013         }
2014
2015         ret = 0;
2016 bail:
2017         return ret;
2018 }
2019
2020 static struct config_item *o2hb_heartbeat_group_make_item(struct config_group *group,
2021                                                           const char *name)
2022 {
2023         struct o2hb_region *reg = NULL;
2024         int ret;
2025
2026         reg = kzalloc(sizeof(struct o2hb_region), GFP_KERNEL);
2027         if (reg == NULL)
2028                 return ERR_PTR(-ENOMEM);
2029
2030         if (strlen(name) > O2HB_MAX_REGION_NAME_LEN) {
2031                 ret = -ENAMETOOLONG;
2032                 goto free;
2033         }
2034
2035         spin_lock(&o2hb_live_lock);
2036         reg->hr_region_num = 0;
2037         if (o2hb_global_heartbeat_active()) {
2038                 reg->hr_region_num = find_first_zero_bit(o2hb_region_bitmap,
2039                                                          O2NM_MAX_REGIONS);
2040                 if (reg->hr_region_num >= O2NM_MAX_REGIONS) {
2041                         spin_unlock(&o2hb_live_lock);
2042                         ret = -EFBIG;
2043                         goto free;
2044                 }
2045                 set_bit(reg->hr_region_num, o2hb_region_bitmap);
2046         }
2047         list_add_tail(&reg->hr_all_item, &o2hb_all_regions);
2048         spin_unlock(&o2hb_live_lock);
2049
2050         config_item_init_type_name(&reg->hr_item, name, &o2hb_region_type);
2051
2052         ret = o2hb_debug_region_init(reg, o2hb_debug_dir);
2053         if (ret) {
2054                 config_item_put(&reg->hr_item);
2055                 goto free;
2056         }
2057
2058         return &reg->hr_item;
2059 free:
2060         kfree(reg);
2061         return ERR_PTR(ret);
2062 }
2063
2064 static void o2hb_heartbeat_group_drop_item(struct config_group *group,
2065                                            struct config_item *item)
2066 {
2067         struct task_struct *hb_task;
2068         struct o2hb_region *reg = to_o2hb_region(item);
2069         int quorum_region = 0;
2070
2071         /* stop the thread when the user removes the region dir */
2072         spin_lock(&o2hb_live_lock);
2073         if (o2hb_global_heartbeat_active()) {
2074                 clear_bit(reg->hr_region_num, o2hb_region_bitmap);
2075                 clear_bit(reg->hr_region_num, o2hb_live_region_bitmap);
2076                 if (test_bit(reg->hr_region_num, o2hb_quorum_region_bitmap))
2077                         quorum_region = 1;
2078                 clear_bit(reg->hr_region_num, o2hb_quorum_region_bitmap);
2079         }
2080         hb_task = reg->hr_task;
2081         reg->hr_task = NULL;
2082         reg->hr_item_dropped = 1;
2083         spin_unlock(&o2hb_live_lock);
2084
2085         if (hb_task)
2086                 kthread_stop(hb_task);
2087
2088         /*
2089          * If we're racing a dev_write(), we need to wake them.  They will
2090          * check reg->hr_task
2091          */
2092         if (atomic_read(&reg->hr_steady_iterations) != 0) {
2093                 atomic_set(&reg->hr_steady_iterations, 0);
2094                 wake_up(&o2hb_steady_queue);
2095         }
2096
2097         if (o2hb_global_heartbeat_active())
2098                 printk(KERN_NOTICE "o2hb: Heartbeat stopped on region %s\n",
2099                        config_item_name(&reg->hr_item));
2100
2101         config_item_put(item);
2102
2103         if (!o2hb_global_heartbeat_active() || !quorum_region)
2104                 return;
2105
2106         /*
2107          * If global heartbeat active and there are dependent users,
2108          * pin all regions if quorum region count <= CUT_OFF
2109          */
2110         spin_lock(&o2hb_live_lock);
2111
2112         if (!o2hb_dependent_users)
2113                 goto unlock;
2114
2115         if (o2hb_pop_count(&o2hb_quorum_region_bitmap,
2116                            O2NM_MAX_REGIONS) <= O2HB_PIN_CUT_OFF)
2117                 o2hb_region_pin(NULL);
2118
2119 unlock:
2120         spin_unlock(&o2hb_live_lock);
2121 }
2122
2123 struct o2hb_heartbeat_group_attribute {
2124         struct configfs_attribute attr;
2125         ssize_t (*show)(struct o2hb_heartbeat_group *, char *);
2126         ssize_t (*store)(struct o2hb_heartbeat_group *, const char *, size_t);
2127 };
2128
2129 static ssize_t o2hb_heartbeat_group_show(struct config_item *item,
2130                                          struct configfs_attribute *attr,
2131                                          char *page)
2132 {
2133         struct o2hb_heartbeat_group *reg = to_o2hb_heartbeat_group(to_config_group(item));
2134         struct o2hb_heartbeat_group_attribute *o2hb_heartbeat_group_attr =
2135                 container_of(attr, struct o2hb_heartbeat_group_attribute, attr);
2136         ssize_t ret = 0;
2137
2138         if (o2hb_heartbeat_group_attr->show)
2139                 ret = o2hb_heartbeat_group_attr->show(reg, page);
2140         return ret;
2141 }
2142
2143 static ssize_t o2hb_heartbeat_group_store(struct config_item *item,
2144                                           struct configfs_attribute *attr,
2145                                           const char *page, size_t count)
2146 {
2147         struct o2hb_heartbeat_group *reg = to_o2hb_heartbeat_group(to_config_group(item));
2148         struct o2hb_heartbeat_group_attribute *o2hb_heartbeat_group_attr =
2149                 container_of(attr, struct o2hb_heartbeat_group_attribute, attr);
2150         ssize_t ret = -EINVAL;
2151
2152         if (o2hb_heartbeat_group_attr->store)
2153                 ret = o2hb_heartbeat_group_attr->store(reg, page, count);
2154         return ret;
2155 }
2156
2157 static ssize_t o2hb_heartbeat_group_threshold_show(struct o2hb_heartbeat_group *group,
2158                                                      char *page)
2159 {
2160         return sprintf(page, "%u\n", o2hb_dead_threshold);
2161 }
2162
2163 static ssize_t o2hb_heartbeat_group_threshold_store(struct o2hb_heartbeat_group *group,
2164                                                     const char *page,
2165                                                     size_t count)
2166 {
2167         unsigned long tmp;
2168         char *p = (char *)page;
2169
2170         tmp = simple_strtoul(p, &p, 10);
2171         if (!p || (*p && (*p != '\n')))
2172                 return -EINVAL;
2173
2174         /* this will validate ranges for us. */
2175         o2hb_dead_threshold_set((unsigned int) tmp);
2176
2177         return count;
2178 }
2179
2180 static
2181 ssize_t o2hb_heartbeat_group_mode_show(struct o2hb_heartbeat_group *group,
2182                                        char *page)
2183 {
2184         return sprintf(page, "%s\n",
2185                        o2hb_heartbeat_mode_desc[o2hb_heartbeat_mode]);
2186 }
2187
2188 static
2189 ssize_t o2hb_heartbeat_group_mode_store(struct o2hb_heartbeat_group *group,
2190                                         const char *page, size_t count)
2191 {
2192         unsigned int i;
2193         int ret;
2194         size_t len;
2195
2196         len = (page[count - 1] == '\n') ? count - 1 : count;
2197         if (!len)
2198                 return -EINVAL;
2199
2200         for (i = 0; i < O2HB_HEARTBEAT_NUM_MODES; ++i) {
2201                 if (strnicmp(page, o2hb_heartbeat_mode_desc[i], len))
2202                         continue;
2203
2204                 ret = o2hb_global_hearbeat_mode_set(i);
2205                 if (!ret)
2206                         printk(KERN_NOTICE "o2hb: Heartbeat mode set to %s\n",
2207                                o2hb_heartbeat_mode_desc[i]);
2208                 return count;
2209         }
2210
2211         return -EINVAL;
2212
2213 }
2214
2215 static struct o2hb_heartbeat_group_attribute o2hb_heartbeat_group_attr_threshold = {
2216         .attr   = { .ca_owner = THIS_MODULE,
2217                     .ca_name = "dead_threshold",
2218                     .ca_mode = S_IRUGO | S_IWUSR },
2219         .show   = o2hb_heartbeat_group_threshold_show,
2220         .store  = o2hb_heartbeat_group_threshold_store,
2221 };
2222
2223 static struct o2hb_heartbeat_group_attribute o2hb_heartbeat_group_attr_mode = {
2224         .attr   = { .ca_owner = THIS_MODULE,
2225                 .ca_name = "mode",
2226                 .ca_mode = S_IRUGO | S_IWUSR },
2227         .show   = o2hb_heartbeat_group_mode_show,
2228         .store  = o2hb_heartbeat_group_mode_store,
2229 };
2230
2231 static struct configfs_attribute *o2hb_heartbeat_group_attrs[] = {
2232         &o2hb_heartbeat_group_attr_threshold.attr,
2233         &o2hb_heartbeat_group_attr_mode.attr,
2234         NULL,
2235 };
2236
2237 static struct configfs_item_operations o2hb_hearbeat_group_item_ops = {
2238         .show_attribute         = o2hb_heartbeat_group_show,
2239         .store_attribute        = o2hb_heartbeat_group_store,
2240 };
2241
2242 static struct configfs_group_operations o2hb_heartbeat_group_group_ops = {
2243         .make_item      = o2hb_heartbeat_group_make_item,
2244         .drop_item      = o2hb_heartbeat_group_drop_item,
2245 };
2246
2247 static struct config_item_type o2hb_heartbeat_group_type = {
2248         .ct_group_ops   = &o2hb_heartbeat_group_group_ops,
2249         .ct_item_ops    = &o2hb_hearbeat_group_item_ops,
2250         .ct_attrs       = o2hb_heartbeat_group_attrs,
2251         .ct_owner       = THIS_MODULE,
2252 };
2253
2254 /* this is just here to avoid touching group in heartbeat.h which the
2255  * entire damn world #includes */
2256 struct config_group *o2hb_alloc_hb_set(void)
2257 {
2258         struct o2hb_heartbeat_group *hs = NULL;
2259         struct config_group *ret = NULL;
2260
2261         hs = kzalloc(sizeof(struct o2hb_heartbeat_group), GFP_KERNEL);
2262         if (hs == NULL)
2263                 goto out;
2264
2265         config_group_init_type_name(&hs->hs_group, "heartbeat",
2266                                     &o2hb_heartbeat_group_type);
2267
2268         ret = &hs->hs_group;
2269 out:
2270         if (ret == NULL)
2271                 kfree(hs);
2272         return ret;
2273 }
2274
2275 void o2hb_free_hb_set(struct config_group *group)
2276 {
2277         struct o2hb_heartbeat_group *hs = to_o2hb_heartbeat_group(group);
2278         kfree(hs);
2279 }
2280
2281 /* hb callback registration and issueing */
2282
2283 static struct o2hb_callback *hbcall_from_type(enum o2hb_callback_type type)
2284 {
2285         if (type == O2HB_NUM_CB)
2286                 return ERR_PTR(-EINVAL);
2287
2288         return &o2hb_callbacks[type];
2289 }
2290
2291 void o2hb_setup_callback(struct o2hb_callback_func *hc,
2292                          enum o2hb_callback_type type,
2293                          o2hb_cb_func *func,
2294                          void *data,
2295                          int priority)
2296 {
2297         INIT_LIST_HEAD(&hc->hc_item);
2298         hc->hc_func = func;
2299         hc->hc_data = data;
2300         hc->hc_priority = priority;
2301         hc->hc_type = type;
2302         hc->hc_magic = O2HB_CB_MAGIC;
2303 }
2304 EXPORT_SYMBOL_GPL(o2hb_setup_callback);
2305
2306 /*
2307  * In local heartbeat mode, region_uuid passed matches the dlm domain name.
2308  * In global heartbeat mode, region_uuid passed is NULL.
2309  *
2310  * In local, we only pin the matching region. In global we pin all the active
2311  * regions.
2312  */
2313 static int o2hb_region_pin(const char *region_uuid)
2314 {
2315         int ret = 0, found = 0;
2316         struct o2hb_region *reg;
2317         char *uuid;
2318
2319         assert_spin_locked(&o2hb_live_lock);
2320
2321         list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) {
2322                 uuid = config_item_name(&reg->hr_item);
2323
2324                 /* local heartbeat */
2325                 if (region_uuid) {
2326                         if (strcmp(region_uuid, uuid))
2327                                 continue;
2328                         found = 1;
2329                 }
2330
2331                 if (reg->hr_item_pinned || reg->hr_item_dropped)
2332                         goto skip_pin;
2333
2334                 /* Ignore ENOENT only for local hb (userdlm domain) */
2335                 ret = o2nm_depend_item(&reg->hr_item);
2336                 if (!ret) {
2337                         mlog(ML_CLUSTER, "Pin region %s\n", uuid);
2338                         reg->hr_item_pinned = 1;
2339                 } else {
2340                         if (ret == -ENOENT && found)
2341                                 ret = 0;
2342                         else {
2343                                 mlog(ML_ERROR, "Pin region %s fails with %d\n",
2344                                      uuid, ret);
2345                                 break;
2346                         }
2347                 }
2348 skip_pin:
2349                 if (found)
2350                         break;
2351         }
2352
2353         return ret;
2354 }
2355
2356 /*
2357  * In local heartbeat mode, region_uuid passed matches the dlm domain name.
2358  * In global heartbeat mode, region_uuid passed is NULL.
2359  *
2360  * In local, we only unpin the matching region. In global we unpin all the
2361  * active regions.
2362  */
2363 static void o2hb_region_unpin(const char *region_uuid)
2364 {
2365         struct o2hb_region *reg;
2366         char *uuid;
2367         int found = 0;
2368
2369         assert_spin_locked(&o2hb_live_lock);
2370
2371         list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) {
2372                 uuid = config_item_name(&reg->hr_item);
2373                 if (region_uuid) {
2374                         if (strcmp(region_uuid, uuid))
2375                                 continue;
2376                         found = 1;
2377                 }
2378
2379                 if (reg->hr_item_pinned) {
2380                         mlog(ML_CLUSTER, "Unpin region %s\n", uuid);
2381                         o2nm_undepend_item(&reg->hr_item);
2382                         reg->hr_item_pinned = 0;
2383                 }
2384                 if (found)
2385                         break;
2386         }
2387 }
2388
2389 static int o2hb_region_inc_user(const char *region_uuid)
2390 {
2391         int ret = 0;
2392
2393         spin_lock(&o2hb_live_lock);
2394
2395         /* local heartbeat */
2396         if (!o2hb_global_heartbeat_active()) {
2397             ret = o2hb_region_pin(region_uuid);
2398             goto unlock;
2399         }
2400
2401         /*
2402          * if global heartbeat active and this is the first dependent user,
2403          * pin all regions if quorum region count <= CUT_OFF
2404          */
2405         o2hb_dependent_users++;
2406         if (o2hb_dependent_users > 1)
2407                 goto unlock;
2408
2409         if (o2hb_pop_count(&o2hb_quorum_region_bitmap,
2410                            O2NM_MAX_REGIONS) <= O2HB_PIN_CUT_OFF)
2411                 ret = o2hb_region_pin(NULL);
2412
2413 unlock:
2414         spin_unlock(&o2hb_live_lock);
2415         return ret;
2416 }
2417
2418 void o2hb_region_dec_user(const char *region_uuid)
2419 {
2420         spin_lock(&o2hb_live_lock);
2421
2422         /* local heartbeat */
2423         if (!o2hb_global_heartbeat_active()) {
2424             o2hb_region_unpin(region_uuid);
2425             goto unlock;
2426         }
2427
2428         /*
2429          * if global heartbeat active and there are no dependent users,
2430          * unpin all quorum regions
2431          */
2432         o2hb_dependent_users--;
2433         if (!o2hb_dependent_users)
2434                 o2hb_region_unpin(NULL);
2435
2436 unlock:
2437         spin_unlock(&o2hb_live_lock);
2438 }
2439
2440 int o2hb_register_callback(const char *region_uuid,
2441                            struct o2hb_callback_func *hc)
2442 {
2443         struct o2hb_callback_func *tmp;
2444         struct list_head *iter;
2445         struct o2hb_callback *hbcall;
2446         int ret;
2447
2448         BUG_ON(hc->hc_magic != O2HB_CB_MAGIC);
2449         BUG_ON(!list_empty(&hc->hc_item));
2450
2451         hbcall = hbcall_from_type(hc->hc_type);
2452         if (IS_ERR(hbcall)) {
2453                 ret = PTR_ERR(hbcall);
2454                 goto out;
2455         }
2456
2457         if (region_uuid) {
2458                 ret = o2hb_region_inc_user(region_uuid);
2459                 if (ret) {
2460                         mlog_errno(ret);
2461                         goto out;
2462                 }
2463         }
2464
2465         down_write(&o2hb_callback_sem);
2466
2467         list_for_each(iter, &hbcall->list) {
2468                 tmp = list_entry(iter, struct o2hb_callback_func, hc_item);
2469                 if (hc->hc_priority < tmp->hc_priority) {
2470                         list_add_tail(&hc->hc_item, iter);
2471                         break;
2472                 }
2473         }
2474         if (list_empty(&hc->hc_item))
2475                 list_add_tail(&hc->hc_item, &hbcall->list);
2476
2477         up_write(&o2hb_callback_sem);
2478         ret = 0;
2479 out:
2480         mlog(ML_CLUSTER, "returning %d on behalf of %p for funcs %p\n",
2481              ret, __builtin_return_address(0), hc);
2482         return ret;
2483 }
2484 EXPORT_SYMBOL_GPL(o2hb_register_callback);
2485
2486 void o2hb_unregister_callback(const char *region_uuid,
2487                               struct o2hb_callback_func *hc)
2488 {
2489         BUG_ON(hc->hc_magic != O2HB_CB_MAGIC);
2490
2491         mlog(ML_CLUSTER, "on behalf of %p for funcs %p\n",
2492              __builtin_return_address(0), hc);
2493
2494         /* XXX Can this happen _with_ a region reference? */
2495         if (list_empty(&hc->hc_item))
2496                 return;
2497
2498         if (region_uuid)
2499                 o2hb_region_dec_user(region_uuid);
2500
2501         down_write(&o2hb_callback_sem);
2502
2503         list_del_init(&hc->hc_item);
2504
2505         up_write(&o2hb_callback_sem);
2506 }
2507 EXPORT_SYMBOL_GPL(o2hb_unregister_callback);
2508
2509 int o2hb_check_node_heartbeating(u8 node_num)
2510 {
2511         unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
2512
2513         o2hb_fill_node_map(testing_map, sizeof(testing_map));
2514         if (!test_bit(node_num, testing_map)) {
2515                 mlog(ML_HEARTBEAT,
2516                      "node (%u) does not have heartbeating enabled.\n",
2517                      node_num);
2518                 return 0;
2519         }
2520
2521         return 1;
2522 }
2523 EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating);
2524
2525 int o2hb_check_node_heartbeating_from_callback(u8 node_num)
2526 {
2527         unsigned long testing_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
2528
2529         o2hb_fill_node_map_from_callback(testing_map, sizeof(testing_map));
2530         if (!test_bit(node_num, testing_map)) {
2531                 mlog(ML_HEARTBEAT,
2532                      "node (%u) does not have heartbeating enabled.\n",
2533                      node_num);
2534                 return 0;
2535         }
2536
2537         return 1;
2538 }
2539 EXPORT_SYMBOL_GPL(o2hb_check_node_heartbeating_from_callback);
2540
2541 /* Makes sure our local node is configured with a node number, and is
2542  * heartbeating. */
2543 int o2hb_check_local_node_heartbeating(void)
2544 {
2545         u8 node_num;
2546
2547         /* if this node was set then we have networking */
2548         node_num = o2nm_this_node();
2549         if (node_num == O2NM_MAX_NODES) {
2550                 mlog(ML_HEARTBEAT, "this node has not been configured.\n");
2551                 return 0;
2552         }
2553
2554         return o2hb_check_node_heartbeating(node_num);
2555 }
2556 EXPORT_SYMBOL_GPL(o2hb_check_local_node_heartbeating);
2557
2558 /*
2559  * this is just a hack until we get the plumbing which flips file systems
2560  * read only and drops the hb ref instead of killing the node dead.
2561  */
2562 void o2hb_stop_all_regions(void)
2563 {
2564         struct o2hb_region *reg;
2565
2566         mlog(ML_ERROR, "stopping heartbeat on all active regions.\n");
2567
2568         spin_lock(&o2hb_live_lock);
2569
2570         list_for_each_entry(reg, &o2hb_all_regions, hr_all_item)
2571                 reg->hr_unclean_stop = 1;
2572
2573         spin_unlock(&o2hb_live_lock);
2574 }
2575 EXPORT_SYMBOL_GPL(o2hb_stop_all_regions);
2576
2577 int o2hb_get_all_regions(char *region_uuids, u8 max_regions)
2578 {
2579         struct o2hb_region *reg;
2580         int numregs = 0;
2581         char *p;
2582
2583         spin_lock(&o2hb_live_lock);
2584
2585         p = region_uuids;
2586         list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) {
2587                 mlog(0, "Region: %s\n", config_item_name(&reg->hr_item));
2588                 if (numregs < max_regions) {
2589                         memcpy(p, config_item_name(&reg->hr_item),
2590                                O2HB_MAX_REGION_NAME_LEN);
2591                         p += O2HB_MAX_REGION_NAME_LEN;
2592                 }
2593                 numregs++;
2594         }
2595
2596         spin_unlock(&o2hb_live_lock);
2597
2598         return numregs;
2599 }
2600 EXPORT_SYMBOL_GPL(o2hb_get_all_regions);
2601
2602 int o2hb_global_heartbeat_active(void)
2603 {
2604         return (o2hb_heartbeat_mode == O2HB_HEARTBEAT_GLOBAL);
2605 }
2606 EXPORT_SYMBOL(o2hb_global_heartbeat_active);