linux/drivers/md/dm-log-userspace-base.c
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   1/*
   2 * Copyright (C) 2006-2009 Red Hat, Inc.
   3 *
   4 * This file is released under the LGPL.
   5 */
   6
   7#include <linux/bio.h>
   8#include <linux/slab.h>
   9#include <linux/dm-dirty-log.h>
  10#include <linux/device-mapper.h>
  11#include <linux/dm-log-userspace.h>
  12#include <linux/module.h>
  13
  14#include "dm-log-userspace-transfer.h"
  15
  16#define DM_LOG_USERSPACE_VSN "1.1.0"
  17
  18struct flush_entry {
  19        int type;
  20        region_t region;
  21        struct list_head list;
  22};
  23
  24/*
  25 * This limit on the number of mark and clear request is, to a degree,
  26 * arbitrary.  However, there is some basis for the choice in the limits
  27 * imposed on the size of data payload by dm-log-userspace-transfer.c:
  28 * dm_consult_userspace().
  29 */
  30#define MAX_FLUSH_GROUP_COUNT 32
  31
  32struct log_c {
  33        struct dm_target *ti;
  34        struct dm_dev *log_dev;
  35        uint32_t region_size;
  36        region_t region_count;
  37        uint64_t luid;
  38        char uuid[DM_UUID_LEN];
  39
  40        char *usr_argv_str;
  41        uint32_t usr_argc;
  42
  43        /*
  44         * in_sync_hint gets set when doing is_remote_recovering.  It
  45         * represents the first region that needs recovery.  IOW, the
  46         * first zero bit of sync_bits.  This can be useful for to limit
  47         * traffic for calls like is_remote_recovering and get_resync_work,
  48         * but be take care in its use for anything else.
  49         */
  50        uint64_t in_sync_hint;
  51
  52        /*
  53         * Mark and clear requests are held until a flush is issued
  54         * so that we can group, and thereby limit, the amount of
  55         * network traffic between kernel and userspace.  The 'flush_lock'
  56         * is used to protect these lists.
  57         */
  58        spinlock_t flush_lock;
  59        struct list_head mark_list;
  60        struct list_head clear_list;
  61};
  62
  63static mempool_t *flush_entry_pool;
  64
  65static void *flush_entry_alloc(gfp_t gfp_mask, void *pool_data)
  66{
  67        return kmalloc(sizeof(struct flush_entry), gfp_mask);
  68}
  69
  70static void flush_entry_free(void *element, void *pool_data)
  71{
  72        kfree(element);
  73}
  74
  75static int userspace_do_request(struct log_c *lc, const char *uuid,
  76                                int request_type, char *data, size_t data_size,
  77                                char *rdata, size_t *rdata_size)
  78{
  79        int r;
  80
  81        /*
  82         * If the server isn't there, -ESRCH is returned,
  83         * and we must keep trying until the server is
  84         * restored.
  85         */
  86retry:
  87        r = dm_consult_userspace(uuid, lc->luid, request_type, data,
  88                                 data_size, rdata, rdata_size);
  89
  90        if (r != -ESRCH)
  91                return r;
  92
  93        DMERR(" Userspace log server not found.");
  94        while (1) {
  95                set_current_state(TASK_INTERRUPTIBLE);
  96                schedule_timeout(2*HZ);
  97                DMWARN("Attempting to contact userspace log server...");
  98                r = dm_consult_userspace(uuid, lc->luid, DM_ULOG_CTR,
  99                                         lc->usr_argv_str,
 100                                         strlen(lc->usr_argv_str) + 1,
 101                                         NULL, NULL);
 102                if (!r)
 103                        break;
 104        }
 105        DMINFO("Reconnected to userspace log server... DM_ULOG_CTR complete");
 106        r = dm_consult_userspace(uuid, lc->luid, DM_ULOG_RESUME, NULL,
 107                                 0, NULL, NULL);
 108        if (!r)
 109                goto retry;
 110
 111        DMERR("Error trying to resume userspace log: %d", r);
 112
 113        return -ESRCH;
 114}
 115
 116static int build_constructor_string(struct dm_target *ti,
 117                                    unsigned argc, char **argv,
 118                                    char **ctr_str)
 119{
 120        int i, str_size;
 121        char *str = NULL;
 122
 123        *ctr_str = NULL;
 124
 125        for (i = 0, str_size = 0; i < argc; i++)
 126                str_size += strlen(argv[i]) + 1; /* +1 for space between args */
 127
 128        str_size += 20; /* Max number of chars in a printed u64 number */
 129
 130        str = kzalloc(str_size, GFP_KERNEL);
 131        if (!str) {
 132                DMWARN("Unable to allocate memory for constructor string");
 133                return -ENOMEM;
 134        }
 135
 136        str_size = sprintf(str, "%llu", (unsigned long long)ti->len);
 137        for (i = 0; i < argc; i++)
 138                str_size += sprintf(str + str_size, " %s", argv[i]);
 139
 140        *ctr_str = str;
 141        return str_size;
 142}
 143
 144/*
 145 * userspace_ctr
 146 *
 147 * argv contains:
 148 *      <UUID> <other args>
 149 * Where 'other args' is the userspace implementation specific log
 150 * arguments.  An example might be:
 151 *      <UUID> clustered-disk <arg count> <log dev> <region_size> [[no]sync]
 152 *
 153 * So, this module will strip off the <UUID> for identification purposes
 154 * when communicating with userspace about a log; but will pass on everything
 155 * else.
 156 */
 157static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 158                         unsigned argc, char **argv)
 159{
 160        int r = 0;
 161        int str_size;
 162        char *ctr_str = NULL;
 163        struct log_c *lc = NULL;
 164        uint64_t rdata;
 165        size_t rdata_size = sizeof(rdata);
 166        char *devices_rdata = NULL;
 167        size_t devices_rdata_size = DM_NAME_LEN;
 168
 169        if (argc < 3) {
 170                DMWARN("Too few arguments to userspace dirty log");
 171                return -EINVAL;
 172        }
 173
 174        lc = kzalloc(sizeof(*lc), GFP_KERNEL);
 175        if (!lc) {
 176                DMWARN("Unable to allocate userspace log context.");
 177                return -ENOMEM;
 178        }
 179
 180        /* The ptr value is sufficient for local unique id */
 181        lc->luid = (unsigned long)lc;
 182
 183        lc->ti = ti;
 184
 185        if (strlen(argv[0]) > (DM_UUID_LEN - 1)) {
 186                DMWARN("UUID argument too long.");
 187                kfree(lc);
 188                return -EINVAL;
 189        }
 190
 191        strncpy(lc->uuid, argv[0], DM_UUID_LEN);
 192        spin_lock_init(&lc->flush_lock);
 193        INIT_LIST_HEAD(&lc->mark_list);
 194        INIT_LIST_HEAD(&lc->clear_list);
 195
 196        str_size = build_constructor_string(ti, argc - 1, argv + 1, &ctr_str);
 197        if (str_size < 0) {
 198                kfree(lc);
 199                return str_size;
 200        }
 201
 202        devices_rdata = kzalloc(devices_rdata_size, GFP_KERNEL);
 203        if (!devices_rdata) {
 204                DMERR("Failed to allocate memory for device information");
 205                r = -ENOMEM;
 206                goto out;
 207        }
 208
 209        /*
 210         * Send table string and get back any opened device.
 211         */
 212        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_CTR,
 213                                 ctr_str, str_size,
 214                                 devices_rdata, &devices_rdata_size);
 215
 216        if (r < 0) {
 217                if (r == -ESRCH)
 218                        DMERR("Userspace log server not found");
 219                else
 220                        DMERR("Userspace log server failed to create log");
 221                goto out;
 222        }
 223
 224        /* Since the region size does not change, get it now */
 225        rdata_size = sizeof(rdata);
 226        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_GET_REGION_SIZE,
 227                                 NULL, 0, (char *)&rdata, &rdata_size);
 228
 229        if (r) {
 230                DMERR("Failed to get region size of dirty log");
 231                goto out;
 232        }
 233
 234        lc->region_size = (uint32_t)rdata;
 235        lc->region_count = dm_sector_div_up(ti->len, lc->region_size);
 236
 237        if (devices_rdata_size) {
 238                if (devices_rdata[devices_rdata_size - 1] != '\0') {
 239                        DMERR("DM_ULOG_CTR device return string not properly terminated");
 240                        r = -EINVAL;
 241                        goto out;
 242                }
 243                r = dm_get_device(ti, devices_rdata,
 244                                  dm_table_get_mode(ti->table), &lc->log_dev);
 245                if (r)
 246                        DMERR("Failed to register %s with device-mapper",
 247                              devices_rdata);
 248        }
 249out:
 250        kfree(devices_rdata);
 251        if (r) {
 252                kfree(lc);
 253                kfree(ctr_str);
 254        } else {
 255                lc->usr_argv_str = ctr_str;
 256                lc->usr_argc = argc;
 257                log->context = lc;
 258        }
 259
 260        return r;
 261}
 262
 263static void userspace_dtr(struct dm_dirty_log *log)
 264{
 265        struct log_c *lc = log->context;
 266
 267        (void) dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_DTR,
 268                                 NULL, 0,
 269                                 NULL, NULL);
 270
 271        if (lc->log_dev)
 272                dm_put_device(lc->ti, lc->log_dev);
 273
 274        kfree(lc->usr_argv_str);
 275        kfree(lc);
 276
 277        return;
 278}
 279
 280static int userspace_presuspend(struct dm_dirty_log *log)
 281{
 282        int r;
 283        struct log_c *lc = log->context;
 284
 285        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_PRESUSPEND,
 286                                 NULL, 0,
 287                                 NULL, NULL);
 288
 289        return r;
 290}
 291
 292static int userspace_postsuspend(struct dm_dirty_log *log)
 293{
 294        int r;
 295        struct log_c *lc = log->context;
 296
 297        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_POSTSUSPEND,
 298                                 NULL, 0,
 299                                 NULL, NULL);
 300
 301        return r;
 302}
 303
 304static int userspace_resume(struct dm_dirty_log *log)
 305{
 306        int r;
 307        struct log_c *lc = log->context;
 308
 309        lc->in_sync_hint = 0;
 310        r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_RESUME,
 311                                 NULL, 0,
 312                                 NULL, NULL);
 313
 314        return r;
 315}
 316
 317static uint32_t userspace_get_region_size(struct dm_dirty_log *log)
 318{
 319        struct log_c *lc = log->context;
 320
 321        return lc->region_size;
 322}
 323
 324/*
 325 * userspace_is_clean
 326 *
 327 * Check whether a region is clean.  If there is any sort of
 328 * failure when consulting the server, we return not clean.
 329 *
 330 * Returns: 1 if clean, 0 otherwise
 331 */
 332static int userspace_is_clean(struct dm_dirty_log *log, region_t region)
 333{
 334        int r;
 335        uint64_t region64 = (uint64_t)region;
 336        int64_t is_clean;
 337        size_t rdata_size;
 338        struct log_c *lc = log->context;
 339
 340        rdata_size = sizeof(is_clean);
 341        r = userspace_do_request(lc, lc->uuid, DM_ULOG_IS_CLEAN,
 342                                 (char *)&region64, sizeof(region64),
 343                                 (char *)&is_clean, &rdata_size);
 344
 345        return (r) ? 0 : (int)is_clean;
 346}
 347
 348/*
 349 * userspace_in_sync
 350 *
 351 * Check if the region is in-sync.  If there is any sort
 352 * of failure when consulting the server, we assume that
 353 * the region is not in sync.
 354 *
 355 * If 'can_block' is set, return immediately
 356 *
 357 * Returns: 1 if in-sync, 0 if not-in-sync, -EWOULDBLOCK
 358 */
 359static int userspace_in_sync(struct dm_dirty_log *log, region_t region,
 360                             int can_block)
 361{
 362        int r;
 363        uint64_t region64 = region;
 364        int64_t in_sync;
 365        size_t rdata_size;
 366        struct log_c *lc = log->context;
 367
 368        /*
 369         * We can never respond directly - even if in_sync_hint is
 370         * set.  This is because another machine could see a device
 371         * failure and mark the region out-of-sync.  If we don't go
 372         * to userspace to ask, we might think the region is in-sync
 373         * and allow a read to pick up data that is stale.  (This is
 374         * very unlikely if a device actually fails; but it is very
 375         * likely if a connection to one device from one machine fails.)
 376         *
 377         * There still might be a problem if the mirror caches the region
 378         * state as in-sync... but then this call would not be made.  So,
 379         * that is a mirror problem.
 380         */
 381        if (!can_block)
 382                return -EWOULDBLOCK;
 383
 384        rdata_size = sizeof(in_sync);
 385        r = userspace_do_request(lc, lc->uuid, DM_ULOG_IN_SYNC,
 386                                 (char *)&region64, sizeof(region64),
 387                                 (char *)&in_sync, &rdata_size);
 388        return (r) ? 0 : (int)in_sync;
 389}
 390
 391static int flush_one_by_one(struct log_c *lc, struct list_head *flush_list)
 392{
 393        int r = 0;
 394        struct flush_entry *fe;
 395
 396        list_for_each_entry(fe, flush_list, list) {
 397                r = userspace_do_request(lc, lc->uuid, fe->type,
 398                                         (char *)&fe->region,
 399                                         sizeof(fe->region),
 400                                         NULL, NULL);
 401                if (r)
 402                        break;
 403        }
 404
 405        return r;
 406}
 407
 408static int flush_by_group(struct log_c *lc, struct list_head *flush_list)
 409{
 410        int r = 0;
 411        int count;
 412        uint32_t type = 0;
 413        struct flush_entry *fe, *tmp_fe;
 414        LIST_HEAD(tmp_list);
 415        uint64_t group[MAX_FLUSH_GROUP_COUNT];
 416
 417        /*
 418         * Group process the requests
 419         */
 420        while (!list_empty(flush_list)) {
 421                count = 0;
 422
 423                list_for_each_entry_safe(fe, tmp_fe, flush_list, list) {
 424                        group[count] = fe->region;
 425                        count++;
 426
 427                        list_move(&fe->list, &tmp_list);
 428
 429                        type = fe->type;
 430                        if (count >= MAX_FLUSH_GROUP_COUNT)
 431                                break;
 432                }
 433
 434                r = userspace_do_request(lc, lc->uuid, type,
 435                                         (char *)(group),
 436                                         count * sizeof(uint64_t),
 437                                         NULL, NULL);
 438                if (r) {
 439                        /* Group send failed.  Attempt one-by-one. */
 440                        list_splice_init(&tmp_list, flush_list);
 441                        r = flush_one_by_one(lc, flush_list);
 442                        break;
 443                }
 444        }
 445
 446        /*
 447         * Must collect flush_entrys that were successfully processed
 448         * as a group so that they will be free'd by the caller.
 449         */
 450        list_splice_init(&tmp_list, flush_list);
 451
 452        return r;
 453}
 454
 455/*
 456 * userspace_flush
 457 *
 458 * This function is ok to block.
 459 * The flush happens in two stages.  First, it sends all
 460 * clear/mark requests that are on the list.  Then it
 461 * tells the server to commit them.  This gives the
 462 * server a chance to optimise the commit, instead of
 463 * doing it for every request.
 464 *
 465 * Additionally, we could implement another thread that
 466 * sends the requests up to the server - reducing the
 467 * load on flush.  Then the flush would have less in
 468 * the list and be responsible for the finishing commit.
 469 *
 470 * Returns: 0 on success, < 0 on failure
 471 */
 472static int userspace_flush(struct dm_dirty_log *log)
 473{
 474        int r = 0;
 475        unsigned long flags;
 476        struct log_c *lc = log->context;
 477        LIST_HEAD(mark_list);
 478        LIST_HEAD(clear_list);
 479        struct flush_entry *fe, *tmp_fe;
 480
 481        spin_lock_irqsave(&lc->flush_lock, flags);
 482        list_splice_init(&lc->mark_list, &mark_list);
 483        list_splice_init(&lc->clear_list, &clear_list);
 484        spin_unlock_irqrestore(&lc->flush_lock, flags);
 485
 486        if (list_empty(&mark_list) && list_empty(&clear_list))
 487                return 0;
 488
 489        r = flush_by_group(lc, &mark_list);
 490        if (r)
 491                goto fail;
 492
 493        r = flush_by_group(lc, &clear_list);
 494        if (r)
 495                goto fail;
 496
 497        r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH,
 498                                 NULL, 0, NULL, NULL);
 499
 500fail:
 501        /*
 502         * We can safely remove these entries, even if failure.
 503         * Calling code will receive an error and will know that
 504         * the log facility has failed.
 505         */
 506        list_for_each_entry_safe(fe, tmp_fe, &mark_list, list) {
 507                list_del(&fe->list);
 508                mempool_free(fe, flush_entry_pool);
 509        }
 510        list_for_each_entry_safe(fe, tmp_fe, &clear_list, list) {
 511                list_del(&fe->list);
 512                mempool_free(fe, flush_entry_pool);
 513        }
 514
 515        if (r)
 516                dm_table_event(lc->ti->table);
 517
 518        return r;
 519}
 520
 521/*
 522 * userspace_mark_region
 523 *
 524 * This function should avoid blocking unless absolutely required.
 525 * (Memory allocation is valid for blocking.)
 526 */
 527static void userspace_mark_region(struct dm_dirty_log *log, region_t region)
 528{
 529        unsigned long flags;
 530        struct log_c *lc = log->context;
 531        struct flush_entry *fe;
 532
 533        /* Wait for an allocation, but _never_ fail */
 534        fe = mempool_alloc(flush_entry_pool, GFP_NOIO);
 535        BUG_ON(!fe);
 536
 537        spin_lock_irqsave(&lc->flush_lock, flags);
 538        fe->type = DM_ULOG_MARK_REGION;
 539        fe->region = region;
 540        list_add(&fe->list, &lc->mark_list);
 541        spin_unlock_irqrestore(&lc->flush_lock, flags);
 542
 543        return;
 544}
 545
 546/*
 547 * userspace_clear_region
 548 *
 549 * This function must not block.
 550 * So, the alloc can't block.  In the worst case, it is ok to
 551 * fail.  It would simply mean we can't clear the region.
 552 * Does nothing to current sync context, but does mean
 553 * the region will be re-sync'ed on a reload of the mirror
 554 * even though it is in-sync.
 555 */
 556static void userspace_clear_region(struct dm_dirty_log *log, region_t region)
 557{
 558        unsigned long flags;
 559        struct log_c *lc = log->context;
 560        struct flush_entry *fe;
 561
 562        /*
 563         * If we fail to allocate, we skip the clearing of
 564         * the region.  This doesn't hurt us in any way, except
 565         * to cause the region to be resync'ed when the
 566         * device is activated next time.
 567         */
 568        fe = mempool_alloc(flush_entry_pool, GFP_ATOMIC);
 569        if (!fe) {
 570                DMERR("Failed to allocate memory to clear region.");
 571                return;
 572        }
 573
 574        spin_lock_irqsave(&lc->flush_lock, flags);
 575        fe->type = DM_ULOG_CLEAR_REGION;
 576        fe->region = region;
 577        list_add(&fe->list, &lc->clear_list);
 578        spin_unlock_irqrestore(&lc->flush_lock, flags);
 579
 580        return;
 581}
 582
 583/*
 584 * userspace_get_resync_work
 585 *
 586 * Get a region that needs recovery.  It is valid to return
 587 * an error for this function.
 588 *
 589 * Returns: 1 if region filled, 0 if no work, <0 on error
 590 */
 591static int userspace_get_resync_work(struct dm_dirty_log *log, region_t *region)
 592{
 593        int r;
 594        size_t rdata_size;
 595        struct log_c *lc = log->context;
 596        struct {
 597                int64_t i; /* 64-bit for mix arch compatibility */
 598                region_t r;
 599        } pkg;
 600
 601        if (lc->in_sync_hint >= lc->region_count)
 602                return 0;
 603
 604        rdata_size = sizeof(pkg);
 605        r = userspace_do_request(lc, lc->uuid, DM_ULOG_GET_RESYNC_WORK,
 606                                 NULL, 0,
 607                                 (char *)&pkg, &rdata_size);
 608
 609        *region = pkg.r;
 610        return (r) ? r : (int)pkg.i;
 611}
 612
 613/*
 614 * userspace_set_region_sync
 615 *
 616 * Set the sync status of a given region.  This function
 617 * must not fail.
 618 */
 619static void userspace_set_region_sync(struct dm_dirty_log *log,
 620                                      region_t region, int in_sync)
 621{
 622        int r;
 623        struct log_c *lc = log->context;
 624        struct {
 625                region_t r;
 626                int64_t i;
 627        } pkg;
 628
 629        pkg.r = region;
 630        pkg.i = (int64_t)in_sync;
 631
 632        r = userspace_do_request(lc, lc->uuid, DM_ULOG_SET_REGION_SYNC,
 633                                 (char *)&pkg, sizeof(pkg),
 634                                 NULL, NULL);
 635
 636        /*
 637         * It would be nice to be able to report failures.
 638         * However, it is easy emough to detect and resolve.
 639         */
 640        return;
 641}
 642
 643/*
 644 * userspace_get_sync_count
 645 *
 646 * If there is any sort of failure when consulting the server,
 647 * we assume that the sync count is zero.
 648 *
 649 * Returns: sync count on success, 0 on failure
 650 */
 651static region_t userspace_get_sync_count(struct dm_dirty_log *log)
 652{
 653        int r;
 654        size_t rdata_size;
 655        uint64_t sync_count;
 656        struct log_c *lc = log->context;
 657
 658        rdata_size = sizeof(sync_count);
 659        r = userspace_do_request(lc, lc->uuid, DM_ULOG_GET_SYNC_COUNT,
 660                                 NULL, 0,
 661                                 (char *)&sync_count, &rdata_size);
 662
 663        if (r)
 664                return 0;
 665
 666        if (sync_count >= lc->region_count)
 667                lc->in_sync_hint = lc->region_count;
 668
 669        return (region_t)sync_count;
 670}
 671
 672/*
 673 * userspace_status
 674 *
 675 * Returns: amount of space consumed
 676 */
 677static int userspace_status(struct dm_dirty_log *log, status_type_t status_type,
 678                            char *result, unsigned maxlen)
 679{
 680        int r = 0;
 681        char *table_args;
 682        size_t sz = (size_t)maxlen;
 683        struct log_c *lc = log->context;
 684
 685        switch (status_type) {
 686        case STATUSTYPE_INFO:
 687                r = userspace_do_request(lc, lc->uuid, DM_ULOG_STATUS_INFO,
 688                                         NULL, 0,
 689                                         result, &sz);
 690
 691                if (r) {
 692                        sz = 0;
 693                        DMEMIT("%s 1 COM_FAILURE", log->type->name);
 694                }
 695                break;
 696        case STATUSTYPE_TABLE:
 697                sz = 0;
 698                table_args = strchr(lc->usr_argv_str, ' ');
 699                BUG_ON(!table_args); /* There will always be a ' ' */
 700                table_args++;
 701
 702                DMEMIT("%s %u %s %s ", log->type->name, lc->usr_argc,
 703                       lc->uuid, table_args);
 704                break;
 705        }
 706        return (r) ? 0 : (int)sz;
 707}
 708
 709/*
 710 * userspace_is_remote_recovering
 711 *
 712 * Returns: 1 if region recovering, 0 otherwise
 713 */
 714static int userspace_is_remote_recovering(struct dm_dirty_log *log,
 715                                          region_t region)
 716{
 717        int r;
 718        uint64_t region64 = region;
 719        struct log_c *lc = log->context;
 720        static unsigned long long limit;
 721        struct {
 722                int64_t is_recovering;
 723                uint64_t in_sync_hint;
 724        } pkg;
 725        size_t rdata_size = sizeof(pkg);
 726
 727        /*
 728         * Once the mirror has been reported to be in-sync,
 729         * it will never again ask for recovery work.  So,
 730         * we can safely say there is not a remote machine
 731         * recovering if the device is in-sync.  (in_sync_hint
 732         * must be reset at resume time.)
 733         */
 734        if (region < lc->in_sync_hint)
 735                return 0;
 736        else if (jiffies < limit)
 737                return 1;
 738
 739        limit = jiffies + (HZ / 4);
 740        r = userspace_do_request(lc, lc->uuid, DM_ULOG_IS_REMOTE_RECOVERING,
 741                                 (char *)&region64, sizeof(region64),
 742                                 (char *)&pkg, &rdata_size);
 743        if (r)
 744                return 1;
 745
 746        lc->in_sync_hint = pkg.in_sync_hint;
 747
 748        return (int)pkg.is_recovering;
 749}
 750
 751static struct dm_dirty_log_type _userspace_type = {
 752        .name = "userspace",
 753        .module = THIS_MODULE,
 754        .ctr = userspace_ctr,
 755        .dtr = userspace_dtr,
 756        .presuspend = userspace_presuspend,
 757        .postsuspend = userspace_postsuspend,
 758        .resume = userspace_resume,
 759        .get_region_size = userspace_get_region_size,
 760        .is_clean = userspace_is_clean,
 761        .in_sync = userspace_in_sync,
 762        .flush = userspace_flush,
 763        .mark_region = userspace_mark_region,
 764        .clear_region = userspace_clear_region,
 765        .get_resync_work = userspace_get_resync_work,
 766        .set_region_sync = userspace_set_region_sync,
 767        .get_sync_count = userspace_get_sync_count,
 768        .status = userspace_status,
 769        .is_remote_recovering = userspace_is_remote_recovering,
 770};
 771
 772static int __init userspace_dirty_log_init(void)
 773{
 774        int r = 0;
 775
 776        flush_entry_pool = mempool_create(100, flush_entry_alloc,
 777                                          flush_entry_free, NULL);
 778
 779        if (!flush_entry_pool) {
 780                DMWARN("Unable to create flush_entry_pool:  No memory.");
 781                return -ENOMEM;
 782        }
 783
 784        r = dm_ulog_tfr_init();
 785        if (r) {
 786                DMWARN("Unable to initialize userspace log communications");
 787                mempool_destroy(flush_entry_pool);
 788                return r;
 789        }
 790
 791        r = dm_dirty_log_type_register(&_userspace_type);
 792        if (r) {
 793                DMWARN("Couldn't register userspace dirty log type");
 794                dm_ulog_tfr_exit();
 795                mempool_destroy(flush_entry_pool);
 796                return r;
 797        }
 798
 799        DMINFO("version " DM_LOG_USERSPACE_VSN " loaded");
 800        return 0;
 801}
 802
 803static void __exit userspace_dirty_log_exit(void)
 804{
 805        dm_dirty_log_type_unregister(&_userspace_type);
 806        dm_ulog_tfr_exit();
 807        mempool_destroy(flush_entry_pool);
 808
 809        DMINFO("version " DM_LOG_USERSPACE_VSN " unloaded");
 810        return;
 811}
 812
 813module_init(userspace_dirty_log_init);
 814module_exit(userspace_dirty_log_exit);
 815
 816MODULE_DESCRIPTION(DM_NAME " userspace dirty log link");
 817MODULE_AUTHOR("Jonathan Brassow <dm-devel@redhat.com>");
 818MODULE_LICENSE("GPL");
 819
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