sbin/hastd/primary.c

   1 /*-
   2  * Copyright (c) 2009 The FreeBSD Foundation
   3  * Copyright (c) 2010-2011 Pawel Jakub Dawidek <pawel@dawidek.net>
   4  * All rights reserved.
   5  *
   6  * This software was developed by Pawel Jakub Dawidek under sponsorship from
   7  * the FreeBSD Foundation.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 #include <sys/cdefs.h>
  32 __FBSDID("$FreeBSD$");
  33
  34 #include <sys/types.h>
  35 #include <sys/time.h>
  36 #include <sys/bio.h>
  37 #include <sys/disk.h>
  38 #include <sys/stat.h>
  39
  40 #include <geom/gate/g_gate.h>
  41
  42 #include <err.h>
  43 #include <errno.h>
  44 #include <fcntl.h>
  45 #include <libgeom.h>
  46 #include <pthread.h>
  47 #include <signal.h>
  48 #include <stdint.h>
  49 #include <stdio.h>
  50 #include <string.h>
  51 #include <sysexits.h>
  52 #include <unistd.h>
  53
  54 #include <activemap.h>
  55 #include <nv.h>
  56 #include <rangelock.h>
  57
  58 #include "control.h"
  59 #include "event.h"
  60 #include "hast.h"
  61 #include "hast_proto.h"
  62 #include "hastd.h"
  63 #include "hooks.h"
  64 #include "metadata.h"
  65 #include "proto.h"
  66 #include "pjdlog.h"
  67 #include "refcnt.h"
  68 #include "subr.h"
  69 #include "synch.h"
  70
  71 /* The is only one remote component for now. */
  72 #define ISREMOTE(no)    ((no) == 1)
  73
  74 struct hio {
  75         /*
  76          * Number of components we are still waiting for.
  77          * When this field goes to 0, we can send the request back to the
  78          * kernel. Each component has to decrease this counter by one
  79          * even on failure.
  80          */
  81         refcnt_t                 hio_countdown;
  82         /*
  83          * Each component has a place to store its own error.
  84          * Once the request is handled by all components we can decide if the
  85          * request overall is successful or not.
  86          */
  87         int                     *hio_errors;
  88         /*
  89          * Structure used to communicate with GEOM Gate class.
  90          */
  91         struct g_gate_ctl_io     hio_ggio;
  92         /*
  93          * Request was already confirmed to GEOM Gate.
  94          */
  95         bool                     hio_done;
  96         /*
  97          * Number of components we are still waiting before sending write
  98          * completion ack to GEOM Gate. Used for memsync.
  99          */
 100         refcnt_t                 hio_writecount;
 101         /*
 102          * Memsync request was acknowleged by remote.
 103          */
 104         bool                     hio_memsyncacked;
 105         /*
 106          * Remember replication from the time the request was initiated,
 107          * so we won't get confused when replication changes on reload.
 108          */
 109         int                      hio_replication;
 110         TAILQ_ENTRY(hio)        *hio_next;
 111 };
 112 #define hio_free_next   hio_next[0]
 113 #define hio_done_next   hio_next[0]
 114
 115 /*
 116  * Free list holds unused structures. When free list is empty, we have to wait
 117  * until some in-progress requests are freed.
 118  */
 119 static TAILQ_HEAD(, hio) hio_free_list;
 120 static size_t hio_free_list_size;
 121 static pthread_mutex_t hio_free_list_lock;
 122 static pthread_cond_t hio_free_list_cond;
 123 /*
 124  * There is one send list for every component. One requests is placed on all
 125  * send lists - each component gets the same request, but each component is
 126  * responsible for managing his own send list.
 127  */
 128 static TAILQ_HEAD(, hio) *hio_send_list;
 129 static size_t *hio_send_list_size;
 130 static pthread_mutex_t *hio_send_list_lock;
 131 static pthread_cond_t *hio_send_list_cond;
 132 #define hio_send_local_list_size        hio_send_list_size[0]
 133 #define hio_send_remote_list_size       hio_send_list_size[1]
 134 /*
 135  * There is one recv list for every component, although local components don't
 136  * use recv lists as local requests are done synchronously.
 137  */
 138 static TAILQ_HEAD(, hio) *hio_recv_list;
 139 static size_t *hio_recv_list_size;
 140 static pthread_mutex_t *hio_recv_list_lock;
 141 static pthread_cond_t *hio_recv_list_cond;
 142 #define hio_recv_remote_list_size       hio_recv_list_size[1]
 143 /*
 144  * Request is placed on done list by the slowest component (the one that
 145  * decreased hio_countdown from 1 to 0).
 146  */
 147 static TAILQ_HEAD(, hio) hio_done_list;
 148 static size_t hio_done_list_size;
 149 static pthread_mutex_t hio_done_list_lock;
 150 static pthread_cond_t hio_done_list_cond;
 151 /*
 152  * Structure below are for interaction with sync thread.
 153  */
 154 static bool sync_inprogress;
 155 static pthread_mutex_t sync_lock;
 156 static pthread_cond_t sync_cond;
 157 /*
 158  * The lock below allows to synchornize access to remote connections.
 159  */
 160 static pthread_rwlock_t *hio_remote_lock;
 161
 162 /*
 163  * Lock to synchronize metadata updates. Also synchronize access to
 164  * hr_primary_localcnt and hr_primary_remotecnt fields.
 165  */
 166 static pthread_mutex_t metadata_lock;
 167
 168 /*
 169  * Maximum number of outstanding I/O requests.
 170  */
 171 #define HAST_HIO_MAX    256
 172 /*
 173  * Number of components. At this point there are only two components: local
 174  * and remote, but in the future it might be possible to use multiple local
 175  * and remote components.
 176  */
 177 #define HAST_NCOMPONENTS        2
 178
 179 #define ISCONNECTED(res, no)    \
 180         ((res)->hr_remotein != NULL && (res)->hr_remoteout != NULL)
 181
 182 #define QUEUE_INSERT1(hio, name, ncomp) do {                            \
 183         mtx_lock(&hio_##name##_list_lock[(ncomp)]);                     \
 184         if (TAILQ_EMPTY(&hio_##name##_list[(ncomp)]))                   \
 185                 cv_broadcast(&hio_##name##_list_cond[(ncomp)]);         \
 186         TAILQ_INSERT_TAIL(&hio_##name##_list[(ncomp)], (hio),           \
 187             hio_next[(ncomp)]);                                         \
 188         hio_##name##_list_size[(ncomp)]++;                              \
 189         mtx_unlock(&hio_##name##_list_lock[(ncomp)]);                   \
 190 } while (0)
 191 #define QUEUE_INSERT2(hio, name)        do {                            \
 192         mtx_lock(&hio_##name##_list_lock);                              \
 193         if (TAILQ_EMPTY(&hio_##name##_list))                            \
 194                 cv_broadcast(&hio_##name##_list_cond);                  \
 195         TAILQ_INSERT_TAIL(&hio_##name##_list, (hio), hio_##name##_next);\
 196         hio_##name##_list_size++;                                       \
 197         mtx_unlock(&hio_##name##_list_lock);                            \
 198 } while (0)
 199 #define QUEUE_TAKE1(hio, name, ncomp, timeout)  do {                    \
 200         bool _last;                                                     \
 201                                                                         \
 202         mtx_lock(&hio_##name##_list_lock[(ncomp)]);                     \
 203         _last = false;                                                  \
 204         while (((hio) = TAILQ_FIRST(&hio_##name##_list[(ncomp)])) == NULL && !_last) { \
 205                 cv_timedwait(&hio_##name##_list_cond[(ncomp)],          \
 206                     &hio_##name##_list_lock[(ncomp)], (timeout));       \
 207                 if ((timeout) != 0)                                     \
 208                         _last = true;                                   \
 209         }                                                               \
 210         if (hio != NULL) {                                              \
 211                 PJDLOG_ASSERT(hio_##name##_list_size[(ncomp)] != 0);    \
 212                 hio_##name##_list_size[(ncomp)]--;                      \
 213                 TAILQ_REMOVE(&hio_##name##_list[(ncomp)], (hio),        \
 214                     hio_next[(ncomp)]);                                 \
 215         }                                                               \
 216         mtx_unlock(&hio_##name##_list_lock[(ncomp)]);                   \
 217 } while (0)
 218 #define QUEUE_TAKE2(hio, name)  do {                                    \
 219         mtx_lock(&hio_##name##_list_lock);                              \
 220         while (((hio) = TAILQ_FIRST(&hio_##name##_list)) == NULL) {     \
 221                 cv_wait(&hio_##name##_list_cond,                        \
 222                     &hio_##name##_list_lock);                           \
 223         }                                                               \
 224         PJDLOG_ASSERT(hio_##name##_list_size != 0);                     \
 225         hio_##name##_list_size--;                                       \
 226         TAILQ_REMOVE(&hio_##name##_list, (hio), hio_##name##_next);     \
 227         mtx_unlock(&hio_##name##_list_lock);                            \
 228 } while (0)
 229
 230 #define ISFULLSYNC(hio) ((hio)->hio_replication == HAST_REPLICATION_FULLSYNC)
 231 #define ISMEMSYNC(hio)  ((hio)->hio_replication == HAST_REPLICATION_MEMSYNC)
 232 #define ISASYNC(hio)    ((hio)->hio_replication == HAST_REPLICATION_ASYNC)
 233
 234 #define SYNCREQ(hio)            do {                                    \
 235         (hio)->hio_ggio.gctl_unit = -1;                                 \
 236         (hio)->hio_ggio.gctl_seq = 1;                                   \
 237 } while (0)
 238 #define ISSYNCREQ(hio)          ((hio)->hio_ggio.gctl_unit == -1)
 239 #define SYNCREQDONE(hio)        do { (hio)->hio_ggio.gctl_unit = -2; } while (0)
 240 #define ISSYNCREQDONE(hio)      ((hio)->hio_ggio.gctl_unit == -2)
 241
 242 #define ISMEMSYNCWRITE(hio)     (ISMEMSYNC(hio) &&                      \
 243             (hio)->hio_ggio.gctl_cmd == BIO_WRITE && !ISSYNCREQ(hio))
 244
 245 static struct hast_resource *gres;
 246
 247 static pthread_mutex_t range_lock;
 248 static struct rangelocks *range_regular;
 249 static bool range_regular_wait;
 250 static pthread_cond_t range_regular_cond;
 251 static struct rangelocks *range_sync;
 252 static bool range_sync_wait;
 253 static pthread_cond_t range_sync_cond;
 254 static bool fullystarted;
 255
 256 static void *ggate_recv_thread(void *arg);
 257 static void *local_send_thread(void *arg);
 258 static void *remote_send_thread(void *arg);
 259 static void *remote_recv_thread(void *arg);
 260 static void *ggate_send_thread(void *arg);
 261 static void *sync_thread(void *arg);
 262 static void *guard_thread(void *arg);
 263
 264 static void
 265 output_status_aux(struct nv *nvout)
 266 {
 267
 268         nv_add_uint64(nvout, (uint64_t)hio_free_list_size,
 269             "idle_queue_size");
 270         nv_add_uint64(nvout, (uint64_t)hio_send_local_list_size,
 271             "local_queue_size");
 272         nv_add_uint64(nvout, (uint64_t)hio_send_remote_list_size,
 273             "send_queue_size");
 274         nv_add_uint64(nvout, (uint64_t)hio_recv_remote_list_size,
 275             "recv_queue_size");
 276         nv_add_uint64(nvout, (uint64_t)hio_done_list_size,
 277             "done_queue_size");
 278 }
 279
 280 static void
 281 cleanup(struct hast_resource *res)
 282 {
 283         int rerrno;
 284
 285         /* Remember errno. */
 286         rerrno = errno;
 287
 288         /* Destroy ggate provider if we created one. */
 289         if (res->hr_ggateunit >= 0) {
 290                 struct g_gate_ctl_destroy ggiod;
 291
 292                 bzero(&ggiod, sizeof(ggiod));
 293                 ggiod.gctl_version = G_GATE_VERSION;
 294                 ggiod.gctl_unit = res->hr_ggateunit;
 295                 ggiod.gctl_force = 1;
 296                 if (ioctl(res->hr_ggatefd, G_GATE_CMD_DESTROY, &ggiod) == -1) {
 297                         pjdlog_errno(LOG_WARNING,
 298                             "Unable to destroy hast/%s device",
 299                             res->hr_provname);
 300                 }
 301                 res->hr_ggateunit = -1;
 302         }
 303
 304         /* Restore errno. */
 305         errno = rerrno;
 306 }
 307
 308 static __dead2 void
 309 primary_exit(int exitcode, const char *fmt, ...)
 310 {
 311         va_list ap;
 312
 313         PJDLOG_ASSERT(exitcode != EX_OK);
 314         va_start(ap, fmt);
 315         pjdlogv_errno(LOG_ERR, fmt, ap);
 316         va_end(ap);
 317         cleanup(gres);
 318         exit(exitcode);
 319 }
 320
 321 static __dead2 void
 322 primary_exitx(int exitcode, const char *fmt, ...)
 323 {
 324         va_list ap;
 325
 326         va_start(ap, fmt);
 327         pjdlogv(exitcode == EX_OK ? LOG_INFO : LOG_ERR, fmt, ap);
 328         va_end(ap);
 329         cleanup(gres);
 330         exit(exitcode);
 331 }
 332
 333 static int
 334 hast_activemap_flush(struct hast_resource *res) __unlocks(res->hr_amp_lock)
 335 {
 336         const unsigned char *buf;
 337         size_t size;
 338         int ret;
 339
 340         mtx_lock(&res->hr_amp_diskmap_lock);
 341         buf = activemap_bitmap(res->hr_amp, &size);
 342         mtx_unlock(&res->hr_amp_lock);
 343         PJDLOG_ASSERT(buf != NULL);
 344         PJDLOG_ASSERT((size % res->hr_local_sectorsize) == 0);
 345         ret = 0;
 346         if (pwrite(res->hr_localfd, buf, size, METADATA_SIZE) !=
 347             (ssize_t)size) {
 348                 pjdlog_errno(LOG_ERR, "Unable to flush activemap to disk");
 349                 res->hr_stat_activemap_write_error++;
 350                 ret = -1;
 351         }
 352         if (ret == 0 && res->hr_metaflush == 1 &&
 353             g_flush(res->hr_localfd) == -1) {
 354                 if (errno == EOPNOTSUPP) {
 355                         pjdlog_warning("The %s provider doesn't support flushing write cache. Disabling it.",
 356                             res->hr_localpath);
 357                         res->hr_metaflush = 0;
 358                 } else {
 359                         pjdlog_errno(LOG_ERR,
 360                             "Unable to flush disk cache on activemap update");
 361                         res->hr_stat_activemap_flush_error++;
 362                         ret = -1;
 363                 }
 364         }
 365         mtx_unlock(&res->hr_amp_diskmap_lock);
 366         return (ret);
 367 }
 368
 369 static bool
 370 real_remote(const struct hast_resource *res)
 371 {
 372
 373         return (strcmp(res->hr_remoteaddr, "none") != 0);
 374 }
 375
 376 static void
 377 init_environment(struct hast_resource *res __unused)
 378 {
 379         struct hio *hio;
 380         unsigned int ii, ncomps;
 381
 382         /*
 383          * In the future it might be per-resource value.
 384          */
 385         ncomps = HAST_NCOMPONENTS;
 386
 387         /*
 388          * Allocate memory needed by lists.
 389          */
 390         hio_send_list = malloc(sizeof(hio_send_list[0]) * ncomps);
 391         if (hio_send_list == NULL) {
 392                 primary_exitx(EX_TEMPFAIL,
 393                     "Unable to allocate %zu bytes of memory for send lists.",
 394                     sizeof(hio_send_list[0]) * ncomps);
 395         }
 396         hio_send_list_size = malloc(sizeof(hio_send_list_size[0]) * ncomps);
 397         if (hio_send_list_size == NULL) {
 398                 primary_exitx(EX_TEMPFAIL,
 399                     "Unable to allocate %zu bytes of memory for send list counters.",
 400                     sizeof(hio_send_list_size[0]) * ncomps);
 401         }
 402         hio_send_list_lock = malloc(sizeof(hio_send_list_lock[0]) * ncomps);
 403         if (hio_send_list_lock == NULL) {
 404                 primary_exitx(EX_TEMPFAIL,
 405                     "Unable to allocate %zu bytes of memory for send list locks.",
 406                     sizeof(hio_send_list_lock[0]) * ncomps);
 407         }
 408         hio_send_list_cond = malloc(sizeof(hio_send_list_cond[0]) * ncomps);
 409         if (hio_send_list_cond == NULL) {
 410                 primary_exitx(EX_TEMPFAIL,
 411                     "Unable to allocate %zu bytes of memory for send list condition variables.",
 412                     sizeof(hio_send_list_cond[0]) * ncomps);
 413         }
 414         hio_recv_list = malloc(sizeof(hio_recv_list[0]) * ncomps);
 415         if (hio_recv_list == NULL) {
 416                 primary_exitx(EX_TEMPFAIL,
 417                     "Unable to allocate %zu bytes of memory for recv lists.",
 418                     sizeof(hio_recv_list[0]) * ncomps);
 419         }
 420         hio_recv_list_size = malloc(sizeof(hio_recv_list_size[0]) * ncomps);
 421         if (hio_recv_list_size == NULL) {
 422                 primary_exitx(EX_TEMPFAIL,
 423                     "Unable to allocate %zu bytes of memory for recv list counters.",
 424                     sizeof(hio_recv_list_size[0]) * ncomps);
 425         }
 426         hio_recv_list_lock = malloc(sizeof(hio_recv_list_lock[0]) * ncomps);
 427         if (hio_recv_list_lock == NULL) {
 428                 primary_exitx(EX_TEMPFAIL,
 429                     "Unable to allocate %zu bytes of memory for recv list locks.",
 430                     sizeof(hio_recv_list_lock[0]) * ncomps);
 431         }
 432         hio_recv_list_cond = malloc(sizeof(hio_recv_list_cond[0]) * ncomps);
 433         if (hio_recv_list_cond == NULL) {
 434                 primary_exitx(EX_TEMPFAIL,
 435                     "Unable to allocate %zu bytes of memory for recv list condition variables.",
 436                     sizeof(hio_recv_list_cond[0]) * ncomps);
 437         }
 438         hio_remote_lock = malloc(sizeof(hio_remote_lock[0]) * ncomps);
 439         if (hio_remote_lock == NULL) {
 440                 primary_exitx(EX_TEMPFAIL,
 441                     "Unable to allocate %zu bytes of memory for remote connections locks.",
 442                     sizeof(hio_remote_lock[0]) * ncomps);
 443         }
 444
 445         /*
 446          * Initialize lists, their counters, locks and condition variables.
 447          */
 448         TAILQ_INIT(&hio_free_list);
 449         mtx_init(&hio_free_list_lock);
 450         cv_init(&hio_free_list_cond);
 451         for (ii = 0; ii < HAST_NCOMPONENTS; ii++) {
 452                 TAILQ_INIT(&hio_send_list[ii]);
 453                 hio_send_list_size[ii] = 0;
 454                 mtx_init(&hio_send_list_lock[ii]);
 455                 cv_init(&hio_send_list_cond[ii]);
 456                 TAILQ_INIT(&hio_recv_list[ii]);
 457                 hio_recv_list_size[ii] = 0;
 458                 mtx_init(&hio_recv_list_lock[ii]);
 459                 cv_init(&hio_recv_list_cond[ii]);
 460                 rw_init(&hio_remote_lock[ii]);
 461         }
 462         TAILQ_INIT(&hio_done_list);
 463         mtx_init(&hio_done_list_lock);
 464         cv_init(&hio_done_list_cond);
 465         mtx_init(&metadata_lock);
 466
 467         /*
 468          * Allocate requests pool and initialize requests.
 469          */
 470         for (ii = 0; ii < HAST_HIO_MAX; ii++) {
 471                 hio = malloc(sizeof(*hio));
 472                 if (hio == NULL) {
 473                         primary_exitx(EX_TEMPFAIL,
 474                             "Unable to allocate %zu bytes of memory for hio request.",
 475                             sizeof(*hio));
 476                 }
 477                 refcnt_init(&hio->hio_countdown, 0);
 478                 hio->hio_errors = malloc(sizeof(hio->hio_errors[0]) * ncomps);
 479                 if (hio->hio_errors == NULL) {
 480                         primary_exitx(EX_TEMPFAIL,
 481                             "Unable allocate %zu bytes of memory for hio errors.",
 482                             sizeof(hio->hio_errors[0]) * ncomps);
 483                 }
 484                 hio->hio_next = malloc(sizeof(hio->hio_next[0]) * ncomps);
 485                 if (hio->hio_next == NULL) {
 486                         primary_exitx(EX_TEMPFAIL,
 487                             "Unable allocate %zu bytes of memory for hio_next field.",
 488                             sizeof(hio->hio_next[0]) * ncomps);
 489                 }
 490                 hio->hio_ggio.gctl_version = G_GATE_VERSION;
 491                 hio->hio_ggio.gctl_data = malloc(MAXPHYS);
 492                 if (hio->hio_ggio.gctl_data == NULL) {
 493                         primary_exitx(EX_TEMPFAIL,
 494                             "Unable to allocate %zu bytes of memory for gctl_data.",
 495                             MAXPHYS);
 496                 }
 497                 hio->hio_ggio.gctl_length = MAXPHYS;
 498                 hio->hio_ggio.gctl_error = 0;
 499                 TAILQ_INSERT_HEAD(&hio_free_list, hio, hio_free_next);
 500                 hio_free_list_size++;
 501         }
 502 }
 503
 504 static bool
 505 init_resuid(struct hast_resource *res)
 506 {
 507
 508         mtx_lock(&metadata_lock);
 509         if (res->hr_resuid != 0) {
 510                 mtx_unlock(&metadata_lock);
 511                 return (false);
 512         } else {
 513                 /* Initialize unique resource identifier. */
 514                 arc4random_buf(&res->hr_resuid, sizeof(res->hr_resuid));
 515                 mtx_unlock(&metadata_lock);
 516                 if (metadata_write(res) == -1)
 517                         exit(EX_NOINPUT);
 518                 return (true);
 519         }
 520 }
 521
 522 static void
 523 init_local(struct hast_resource *res)
 524 {
 525         unsigned char *buf;
 526         size_t mapsize;
 527
 528         if (metadata_read(res, true) == -1)
 529                 exit(EX_NOINPUT);
 530         mtx_init(&res->hr_amp_lock);
 531         if (activemap_init(&res->hr_amp, res->hr_datasize, res->hr_extentsize,
 532             res->hr_local_sectorsize, res->hr_keepdirty) == -1) {
 533                 primary_exit(EX_TEMPFAIL, "Unable to create activemap");
 534         }
 535         mtx_init(&range_lock);
 536         cv_init(&range_regular_cond);
 537         if (rangelock_init(&range_regular) == -1)
 538                 primary_exit(EX_TEMPFAIL, "Unable to create regular range lock");
 539         cv_init(&range_sync_cond);
 540         if (rangelock_init(&range_sync) == -1)
 541                 primary_exit(EX_TEMPFAIL, "Unable to create sync range lock");
 542         mapsize = activemap_ondisk_size(res->hr_amp);
 543         buf = calloc(1, mapsize);
 544         if (buf == NULL) {
 545                 primary_exitx(EX_TEMPFAIL,
 546                     "Unable to allocate buffer for activemap.");
 547         }
 548         if (pread(res->hr_localfd, buf, mapsize, METADATA_SIZE) !=
 549             (ssize_t)mapsize) {
 550                 primary_exit(EX_NOINPUT, "Unable to read activemap");
 551         }
 552         activemap_copyin(res->hr_amp, buf, mapsize);
 553         free(buf);
 554         if (res->hr_resuid != 0)
 555                 return;
 556         /*
 557          * We're using provider for the first time. Initialize local and remote
 558          * counters. We don't initialize resuid here, as we want to do it just
 559          * in time. The reason for this is that we want to inform secondary
 560          * that there were no writes yet, so there is no need to synchronize
 561          * anything.
 562          */
 563         res->hr_primary_localcnt = 0;
 564         res->hr_primary_remotecnt = 0;
 565         if (metadata_write(res) == -1)
 566                 exit(EX_NOINPUT);
 567 }
 568
 569 static int
 570 primary_connect(struct hast_resource *res, struct proto_conn **connp)
 571 {
 572         struct proto_conn *conn;
 573         int16_t val;
 574
 575         val = 1;
 576         if (proto_send(res->hr_conn, &val, sizeof(val)) == -1) {
 577                 primary_exit(EX_TEMPFAIL,
 578                     "Unable to send connection request to parent");
 579         }
 580         if (proto_recv(res->hr_conn, &val, sizeof(val)) == -1) {
 581                 primary_exit(EX_TEMPFAIL,
 582                     "Unable to receive reply to connection request from parent");
 583         }
 584         if (val != 0) {
 585                 errno = val;
 586                 pjdlog_errno(LOG_WARNING, "Unable to connect to %s",
 587                     res->hr_remoteaddr);
 588                 return (-1);
 589         }
 590         if (proto_connection_recv(res->hr_conn, true, &conn) == -1) {
 591                 primary_exit(EX_TEMPFAIL,
 592                     "Unable to receive connection from parent");
 593         }
 594         if (proto_connect_wait(conn, res->hr_timeout) == -1) {
 595                 pjdlog_errno(LOG_WARNING, "Unable to connect to %s",
 596                     res->hr_remoteaddr);
 597                 proto_close(conn);
 598                 return (-1);
 599         }
 600         /* Error in setting timeout is not critical, but why should it fail? */
 601         if (proto_timeout(conn, res->hr_timeout) == -1)
 602                 pjdlog_errno(LOG_WARNING, "Unable to set connection timeout");
 603
 604         *connp = conn;
 605
 606         return (0);
 607 }
 608
 609 /*
 610  * Function instructs GEOM_GATE to handle reads directly from within the kernel.
 611  */
 612 static void
 613 enable_direct_reads(struct hast_resource *res)
 614 {
 615         struct g_gate_ctl_modify ggiomodify;
 616
 617         bzero(&ggiomodify, sizeof(ggiomodify));
 618         ggiomodify.gctl_version = G_GATE_VERSION;
 619         ggiomodify.gctl_unit = res->hr_ggateunit;
 620         ggiomodify.gctl_modify = GG_MODIFY_READPROV | GG_MODIFY_READOFFSET;
 621         strlcpy(ggiomodify.gctl_readprov, res->hr_localpath,
 622             sizeof(ggiomodify.gctl_readprov));
 623         ggiomodify.gctl_readoffset = res->hr_localoff;
 624         if (ioctl(res->hr_ggatefd, G_GATE_CMD_MODIFY, &ggiomodify) == 0)
 625                 pjdlog_debug(1, "Direct reads enabled.");
 626         else
 627                 pjdlog_errno(LOG_WARNING, "Failed to enable direct reads");
 628 }
 629
 630 static int
 631 init_remote(struct hast_resource *res, struct proto_conn **inp,
 632     struct proto_conn **outp)
 633 {
 634         struct proto_conn *in, *out;
 635         struct nv *nvout, *nvin;
 636         const unsigned char *token;
 637         unsigned char *map;
 638         const char *errmsg;
 639         int32_t extentsize;
 640         int64_t datasize;
 641         uint32_t mapsize;
 642         uint8_t version;
 643         size_t size;
 644         int error;
 645
 646         PJDLOG_ASSERT((inp == NULL && outp == NULL) || (inp != NULL && outp != NULL));
 647         PJDLOG_ASSERT(real_remote(res));
 648
 649         in = out = NULL;
 650         errmsg = NULL;
 651
 652         if (primary_connect(res, &out) == -1)
 653                 return (ECONNREFUSED);
 654
 655         error = ECONNABORTED;
 656
 657         /*
 658          * First handshake step.
 659          * Setup outgoing connection with remote node.
 660          */
 661         nvout = nv_alloc();
 662         nv_add_string(nvout, res->hr_name, "resource");
 663         nv_add_uint8(nvout, HAST_PROTO_VERSION, "version");
 664         if (nv_error(nvout) != 0) {
 665                 pjdlog_common(LOG_WARNING, 0, nv_error(nvout),
 666                     "Unable to allocate header for connection with %s",
 667                     res->hr_remoteaddr);
 668                 nv_free(nvout);
 669                 goto close;
 670         }
 671         if (hast_proto_send(res, out, nvout, NULL, 0) == -1) {
 672                 pjdlog_errno(LOG_WARNING,
 673                     "Unable to send handshake header to %s",
 674                     res->hr_remoteaddr);
 675                 nv_free(nvout);
 676                 goto close;
 677         }
 678         nv_free(nvout);
 679         if (hast_proto_recv_hdr(out, &nvin) == -1) {
 680                 pjdlog_errno(LOG_WARNING,
 681                     "Unable to receive handshake header from %s",
 682                     res->hr_remoteaddr);
 683                 goto close;
 684         }
 685         errmsg = nv_get_string(nvin, "errmsg");
 686         if (errmsg != NULL) {
 687                 pjdlog_warning("%s", errmsg);
 688                 if (nv_exists(nvin, "wait"))
 689                         error = EBUSY;
 690                 nv_free(nvin);
 691                 goto close;
 692         }
 693         version = nv_get_uint8(nvin, "version");
 694         if (version == 0) {
 695                 /*
 696                  * If no version is sent, it means this is protocol version 1.
 697                  */
 698                 version = 1;
 699         }
 700         if (version > HAST_PROTO_VERSION) {
 701                 pjdlog_warning("Invalid version received (%hhu).", version);
 702                 nv_free(nvin);
 703                 goto close;
 704         }
 705         res->hr_version = version;
 706         pjdlog_debug(1, "Negotiated protocol version %d.", res->hr_version);
 707         token = nv_get_uint8_array(nvin, &size, "token");
 708         if (token == NULL) {
 709                 pjdlog_warning("Handshake header from %s has no 'token' field.",
 710                     res->hr_remoteaddr);
 711                 nv_free(nvin);
 712                 goto close;
 713         }
 714         if (size != sizeof(res->hr_token)) {
 715                 pjdlog_warning("Handshake header from %s contains 'token' of wrong size (got %zu, expected %zu).",
 716                     res->hr_remoteaddr, size, sizeof(res->hr_token));
 717                 nv_free(nvin);
 718                 goto close;
 719         }
 720         bcopy(token, res->hr_token, sizeof(res->hr_token));
 721         nv_free(nvin);
 722
 723         /*
 724          * Second handshake step.
 725          * Setup incoming connection with remote node.
 726          */
 727         if (primary_connect(res, &in) == -1)
 728                 goto close;
 729
 730         nvout = nv_alloc();
 731         nv_add_string(nvout, res->hr_name, "resource");
 732         nv_add_uint8_array(nvout, res->hr_token, sizeof(res->hr_token),
 733             "token");
 734         if (res->hr_resuid == 0) {
 735                 /*
 736                  * The resuid field was not yet initialized.
 737                  * Because we do synchronization inside init_resuid(), it is
 738                  * possible that someone already initialized it, the function
 739                  * will return false then, but if we successfully initialized
 740                  * it, we will get true. True means that there were no writes
 741                  * to this resource yet and we want to inform secondary that
 742                  * synchronization is not needed by sending "virgin" argument.
 743                  */
 744                 if (init_resuid(res))
 745                         nv_add_int8(nvout, 1, "virgin");
 746         }
 747         nv_add_uint64(nvout, res->hr_resuid, "resuid");
 748         nv_add_uint64(nvout, res->hr_primary_localcnt, "localcnt");
 749         nv_add_uint64(nvout, res->hr_primary_remotecnt, "remotecnt");
 750         if (nv_error(nvout) != 0) {
 751                 pjdlog_common(LOG_WARNING, 0, nv_error(nvout),
 752                     "Unable to allocate header for connection with %s",
 753                     res->hr_remoteaddr);
 754                 nv_free(nvout);
 755                 goto close;
 756         }
 757         if (hast_proto_send(res, in, nvout, NULL, 0) == -1) {
 758                 pjdlog_errno(LOG_WARNING,
 759                     "Unable to send handshake header to %s",
 760                     res->hr_remoteaddr);
 761                 nv_free(nvout);
 762                 goto close;
 763         }
 764         nv_free(nvout);
 765         if (hast_proto_recv_hdr(out, &nvin) == -1) {
 766                 pjdlog_errno(LOG_WARNING,
 767                     "Unable to receive handshake header from %s",
 768                     res->hr_remoteaddr);
 769                 goto close;
 770         }
 771         errmsg = nv_get_string(nvin, "errmsg");
 772         if (errmsg != NULL) {
 773                 pjdlog_warning("%s", errmsg);
 774                 nv_free(nvin);
 775                 goto close;
 776         }
 777         datasize = nv_get_int64(nvin, "datasize");
 778         if (datasize != res->hr_datasize) {
 779                 pjdlog_warning("Data size differs between nodes (local=%jd, remote=%jd).",
 780                     (intmax_t)res->hr_datasize, (intmax_t)datasize);
 781                 nv_free(nvin);
 782                 goto close;
 783         }
 784         extentsize = nv_get_int32(nvin, "extentsize");
 785         if (extentsize != res->hr_extentsize) {
 786                 pjdlog_warning("Extent size differs between nodes (local=%zd, remote=%zd).",
 787                     (ssize_t)res->hr_extentsize, (ssize_t)extentsize);
 788                 nv_free(nvin);
 789                 goto close;
 790         }
 791         res->hr_secondary_localcnt = nv_get_uint64(nvin, "localcnt");
 792         res->hr_secondary_remotecnt = nv_get_uint64(nvin, "remotecnt");
 793         res->hr_syncsrc = nv_get_uint8(nvin, "syncsrc");
 794         if (res->hr_syncsrc == HAST_SYNCSRC_PRIMARY)
 795                 enable_direct_reads(res);
 796         if (nv_exists(nvin, "virgin")) {
 797                 /*
 798                  * Secondary was reinitialized, bump localcnt if it is 0 as
 799                  * only we have the data.
 800                  */
 801                 PJDLOG_ASSERT(res->hr_syncsrc == HAST_SYNCSRC_PRIMARY);
 802                 PJDLOG_ASSERT(res->hr_secondary_localcnt == 0);
 803
 804                 if (res->hr_primary_localcnt == 0) {
 805                         PJDLOG_ASSERT(res->hr_secondary_remotecnt == 0);
 806
 807                         mtx_lock(&metadata_lock);
 808                         res->hr_primary_localcnt++;
 809                         pjdlog_debug(1, "Increasing localcnt to %ju.",
 810                             (uintmax_t)res->hr_primary_localcnt);
 811                         (void)metadata_write(res);
 812                         mtx_unlock(&metadata_lock);
 813                 }
 814         }
 815         map = NULL;
 816         mapsize = nv_get_uint32(nvin, "mapsize");
 817         if (mapsize > 0) {
 818                 map = malloc(mapsize);
 819                 if (map == NULL) {
 820                         pjdlog_error("Unable to allocate memory for remote activemap (mapsize=%ju).",
 821                             (uintmax_t)mapsize);
 822                         nv_free(nvin);
 823                         goto close;
 824                 }
 825                 /*
 826                  * Remote node have some dirty extents on its own, lets
 827                  * download its activemap.
 828                  */
 829                 if (hast_proto_recv_data(res, out, nvin, map,
 830                     mapsize) == -1) {
 831                         pjdlog_errno(LOG_ERR,
 832                             "Unable to receive remote activemap");
 833                         nv_free(nvin);
 834                         free(map);
 835                         goto close;
 836                 }
 837                 mtx_lock(&res->hr_amp_lock);
 838                 /*
 839                  * Merge local and remote bitmaps.
 840                  */
 841                 activemap_merge(res->hr_amp, map, mapsize);
 842                 free(map);
 843                 /*
 844                  * Now that we merged bitmaps from both nodes, flush it to the
 845                  * disk before we start to synchronize.
 846                  */
 847                 (void)hast_activemap_flush(res);
 848         }
 849         nv_free(nvin);
 850 #ifdef notyet
 851         /* Setup directions. */
 852         if (proto_send(out, NULL, 0) == -1)
 853                 pjdlog_errno(LOG_WARNING, "Unable to set connection direction");
 854         if (proto_recv(in, NULL, 0) == -1)
 855                 pjdlog_errno(LOG_WARNING, "Unable to set connection direction");
 856 #endif
 857         pjdlog_info("Connected to %s.", res->hr_remoteaddr);
 858         if (res->hr_original_replication == HAST_REPLICATION_MEMSYNC &&
 859             res->hr_version < 2) {
 860                 pjdlog_warning("The 'memsync' replication mode is not supported by the remote node, falling back to 'fullsync' mode.");
 861                 res->hr_replication = HAST_REPLICATION_FULLSYNC;
 862         } else if (res->hr_replication != res->hr_original_replication) {
 863                 /*
 864                  * This is in case hastd disconnected and was upgraded.
 865                  */
 866                 res->hr_replication = res->hr_original_replication;
 867         }
 868         if (inp != NULL && outp != NULL) {
 869                 *inp = in;
 870                 *outp = out;
 871         } else {
 872                 res->hr_remotein = in;
 873                 res->hr_remoteout = out;
 874         }
 875         event_send(res, EVENT_CONNECT);
 876         return (0);
 877 close:
 878         if (errmsg != NULL && strcmp(errmsg, "Split-brain condition!") == 0)
 879                 event_send(res, EVENT_SPLITBRAIN);
 880         proto_close(out);
 881         if (in != NULL)
 882                 proto_close(in);
 883         return (error);
 884 }
 885
 886 static void
 887 sync_start(void)
 888 {
 889
 890         mtx_lock(&sync_lock);
 891         sync_inprogress = true;
 892         mtx_unlock(&sync_lock);
 893         cv_signal(&sync_cond);
 894 }
 895
 896 static void
 897 sync_stop(void)
 898 {
 899
 900         mtx_lock(&sync_lock);
 901         if (sync_inprogress)
 902                 sync_inprogress = false;
 903         mtx_unlock(&sync_lock);
 904 }
 905
 906 static void
 907 init_ggate(struct hast_resource *res)
 908 {
 909         struct g_gate_ctl_create ggiocreate;
 910         struct g_gate_ctl_cancel ggiocancel;
 911
 912         /*
 913          * We communicate with ggate via /dev/ggctl. Open it.
 914          */
 915         res->hr_ggatefd = open("/dev/" G_GATE_CTL_NAME, O_RDWR);
 916         if (res->hr_ggatefd == -1)
 917                 primary_exit(EX_OSFILE, "Unable to open /dev/" G_GATE_CTL_NAME);
 918         /*
 919          * Create provider before trying to connect, as connection failure
 920          * is not critical, but may take some time.
 921          */
 922         bzero(&ggiocreate, sizeof(ggiocreate));
 923         ggiocreate.gctl_version = G_GATE_VERSION;
 924         ggiocreate.gctl_mediasize = res->hr_datasize;
 925         ggiocreate.gctl_sectorsize = res->hr_local_sectorsize;
 926         ggiocreate.gctl_flags = 0;
 927         ggiocreate.gctl_maxcount = 0;
 928         ggiocreate.gctl_timeout = 0;
 929         ggiocreate.gctl_unit = G_GATE_NAME_GIVEN;
 930         snprintf(ggiocreate.gctl_name, sizeof(ggiocreate.gctl_name), "hast/%s",
 931             res->hr_provname);
 932         if (ioctl(res->hr_ggatefd, G_GATE_CMD_CREATE, &ggiocreate) == 0) {
 933                 pjdlog_info("Device hast/%s created.", res->hr_provname);
 934                 res->hr_ggateunit = ggiocreate.gctl_unit;
 935                 return;
 936         }
 937         if (errno != EEXIST) {
 938                 primary_exit(EX_OSERR, "Unable to create hast/%s device",
 939                     res->hr_provname);
 940         }
 941         pjdlog_debug(1,
 942             "Device hast/%s already exists, we will try to take it over.",
 943             res->hr_provname);
 944         /*
 945          * If we received EEXIST, we assume that the process who created the
 946          * provider died and didn't clean up. In that case we will start from
 947          * where he left of.
 948          */
 949         bzero(&ggiocancel, sizeof(ggiocancel));
 950         ggiocancel.gctl_version = G_GATE_VERSION;
 951         ggiocancel.gctl_unit = G_GATE_NAME_GIVEN;
 952         snprintf(ggiocancel.gctl_name, sizeof(ggiocancel.gctl_name), "hast/%s",
 953             res->hr_provname);
 954         if (ioctl(res->hr_ggatefd, G_GATE_CMD_CANCEL, &ggiocancel) == 0) {
 955                 pjdlog_info("Device hast/%s recovered.", res->hr_provname);
 956                 res->hr_ggateunit = ggiocancel.gctl_unit;
 957                 return;
 958         }
 959         primary_exit(EX_OSERR, "Unable to take over hast/%s device",
 960             res->hr_provname);
 961 }
 962
 963 void
 964 hastd_primary(struct hast_resource *res)
 965 {
 966         pthread_t td;
 967         pid_t pid;
 968         int error, mode, debuglevel;
 969
 970         /*
 971          * Create communication channel for sending control commands from
 972          * parent to child.
 973          */
 974         if (proto_client(NULL, "socketpair://", &res->hr_ctrl) == -1) {
 975                 /* TODO: There's no need for this to be fatal error. */
 976                 KEEP_ERRNO((void)pidfile_remove(pfh));
 977                 pjdlog_exit(EX_OSERR,
 978                     "Unable to create control sockets between parent and child");
 979         }
 980         /*
 981          * Create communication channel for sending events from child to parent.
 982          */
 983         if (proto_client(NULL, "socketpair://", &res->hr_event) == -1) {
 984                 /* TODO: There's no need for this to be fatal error. */
 985                 KEEP_ERRNO((void)pidfile_remove(pfh));
 986                 pjdlog_exit(EX_OSERR,
 987                     "Unable to create event sockets between child and parent");
 988         }
 989         /*
 990          * Create communication channel for sending connection requests from
 991          * child to parent.
 992          */
 993         if (proto_client(NULL, "socketpair://", &res->hr_conn) == -1) {
 994                 /* TODO: There's no need for this to be fatal error. */
 995                 KEEP_ERRNO((void)pidfile_remove(pfh));
 996                 pjdlog_exit(EX_OSERR,
 997                     "Unable to create connection sockets between child and parent");
 998         }
 999
1000         pid = fork();
1001         if (pid == -1) {
1002                 /* TODO: There's no need for this to be fatal error. */
1003                 KEEP_ERRNO((void)pidfile_remove(pfh));
1004                 pjdlog_exit(EX_TEMPFAIL, "Unable to fork");
1005         }
1006
1007         if (pid > 0) {
1008                 /* This is parent. */
1009                 /* Declare that we are receiver. */
1010                 proto_recv(res->hr_event, NULL, 0);
1011                 proto_recv(res->hr_conn, NULL, 0);
1012                 /* Declare that we are sender. */
1013                 proto_send(res->hr_ctrl, NULL, 0);
1014                 res->hr_workerpid = pid;
1015                 return;
1016         }
1017
1018         gres = res;
1019         res->output_status_aux = output_status_aux;
1020         mode = pjdlog_mode_get();
1021         debuglevel = pjdlog_debug_get();
1022
1023         /* Declare that we are sender. */
1024         proto_send(res->hr_event, NULL, 0);
1025         proto_send(res->hr_conn, NULL, 0);
1026         /* Declare that we are receiver. */
1027         proto_recv(res->hr_ctrl, NULL, 0);
1028         descriptors_cleanup(res);
1029
1030         descriptors_assert(res, mode);
1031
1032         pjdlog_init(mode);
1033         pjdlog_debug_set(debuglevel);
1034         pjdlog_prefix_set("[%s] (%s) ", res->hr_name, role2str(res->hr_role));
1035         setproctitle("%s (%s)", res->hr_name, role2str(res->hr_role));
1036
1037         init_local(res);
1038         init_ggate(res);
1039         init_environment(res);
1040
1041         if (drop_privs(res) != 0) {
1042                 cleanup(res);
1043                 exit(EX_CONFIG);
1044         }
1045         pjdlog_info("Privileges successfully dropped.");
1046
1047         /*
1048          * Create the guard thread first, so we can handle signals from the
1049          * very beginning.
1050          */
1051         error = pthread_create(&td, NULL, guard_thread, res);
1052         PJDLOG_ASSERT(error == 0);
1053         /*
1054          * Create the control thread before sending any event to the parent,
1055          * as we can deadlock when parent sends control request to worker,
1056          * but worker has no control thread started yet, so parent waits.
1057          * In the meantime worker sends an event to the parent, but parent
1058          * is unable to handle the event, because it waits for control
1059          * request response.
1060          */
1061         error = pthread_create(&td, NULL, ctrl_thread, res);
1062         PJDLOG_ASSERT(error == 0);
1063         if (real_remote(res)) {
1064                 error = init_remote(res, NULL, NULL);
1065                 if (error == 0) {
1066                         sync_start();
1067                 } else if (error == EBUSY) {
1068                         time_t start = time(NULL);
1069
1070                         pjdlog_warning("Waiting for remote node to become %s for %ds.",
1071                             role2str(HAST_ROLE_SECONDARY),
1072                             res->hr_timeout);
1073                         for (;;) {
1074                                 sleep(1);
1075                                 error = init_remote(res, NULL, NULL);
1076                                 if (error != EBUSY)
1077                                         break;
1078                                 if (time(NULL) > start + res->hr_timeout)
1079                                         break;
1080                         }
1081                         if (error == EBUSY) {
1082                                 pjdlog_warning("Remote node is still %s, starting anyway.",
1083                                     role2str(HAST_ROLE_PRIMARY));
1084                         }
1085                 }
1086         }
1087         error = pthread_create(&td, NULL, ggate_recv_thread, res);
1088         PJDLOG_ASSERT(error == 0);
1089         error = pthread_create(&td, NULL, local_send_thread, res);
1090         PJDLOG_ASSERT(error == 0);
1091         error = pthread_create(&td, NULL, remote_send_thread, res);
1092         PJDLOG_ASSERT(error == 0);
1093         error = pthread_create(&td, NULL, remote_recv_thread, res);
1094         PJDLOG_ASSERT(error == 0);
1095         error = pthread_create(&td, NULL, ggate_send_thread, res);
1096         PJDLOG_ASSERT(error == 0);
1097         fullystarted = true;
1098         (void)sync_thread(res);
1099 }
1100
1101 static void
1102 reqlog(int loglevel, int debuglevel, struct g_gate_ctl_io *ggio,
1103     const char *fmt, ...)
1104 {
1105         char msg[1024];
1106         va_list ap;
1107
1108         va_start(ap, fmt);
1109         (void)vsnprintf(msg, sizeof(msg), fmt, ap);
1110         va_end(ap);
1111         switch (ggio->gctl_cmd) {
1112         case BIO_READ:
1113                 (void)snprlcat(msg, sizeof(msg), "READ(%ju, %ju).",
1114                     (uintmax_t)ggio->gctl_offset, (uintmax_t)ggio->gctl_length);
1115                 break;
1116         case BIO_DELETE:
1117                 (void)snprlcat(msg, sizeof(msg), "DELETE(%ju, %ju).",
1118                     (uintmax_t)ggio->gctl_offset, (uintmax_t)ggio->gctl_length);
1119                 break;
1120         case BIO_FLUSH:
1121                 (void)snprlcat(msg, sizeof(msg), "FLUSH.");
1122                 break;
1123         case BIO_WRITE:
1124                 (void)snprlcat(msg, sizeof(msg), "WRITE(%ju, %ju).",
1125                     (uintmax_t)ggio->gctl_offset, (uintmax_t)ggio->gctl_length);
1126                 break;
1127         default:
1128                 (void)snprlcat(msg, sizeof(msg), "UNKNOWN(%u).",
1129                     (unsigned int)ggio->gctl_cmd);
1130                 break;
1131         }
1132         pjdlog_common(loglevel, debuglevel, -1, "%s", msg);
1133 }
1134
1135 static void
1136 remote_close(struct hast_resource *res, int ncomp)
1137 {
1138
1139         rw_wlock(&hio_remote_lock[ncomp]);
1140         /*
1141          * Check for a race between dropping rlock and acquiring wlock -
1142          * another thread can close connection in-between.
1143          */
1144         if (!ISCONNECTED(res, ncomp)) {
1145                 PJDLOG_ASSERT(res->hr_remotein == NULL);
1146                 PJDLOG_ASSERT(res->hr_remoteout == NULL);
1147                 rw_unlock(&hio_remote_lock[ncomp]);
1148                 return;
1149         }
1150
1151         PJDLOG_ASSERT(res->hr_remotein != NULL);
1152         PJDLOG_ASSERT(res->hr_remoteout != NULL);
1153
1154         pjdlog_debug(2, "Closing incoming connection to %s.",
1155             res->hr_remoteaddr);
1156         proto_close(res->hr_remotein);
1157         res->hr_remotein = NULL;
1158         pjdlog_debug(2, "Closing outgoing connection to %s.",
1159             res->hr_remoteaddr);
1160         proto_close(res->hr_remoteout);
1161         res->hr_remoteout = NULL;
1162
1163         rw_unlock(&hio_remote_lock[ncomp]);
1164
1165         pjdlog_warning("Disconnected from %s.", res->hr_remoteaddr);
1166
1167         /*
1168          * Stop synchronization if in-progress.
1169          */
1170         sync_stop();
1171
1172         event_send(res, EVENT_DISCONNECT);
1173 }
1174
1175 /*
1176  * Acknowledge write completion to the kernel, but don't update activemap yet.
1177  */
1178 static void
1179 write_complete(struct hast_resource *res, struct hio *hio)
1180 {
1181         struct g_gate_ctl_io *ggio;
1182         unsigned int ncomp;
1183
1184         PJDLOG_ASSERT(!hio->hio_done);
1185
1186         ggio = &hio->hio_ggio;
1187         PJDLOG_ASSERT(ggio->gctl_cmd == BIO_WRITE);
1188
1189         /*
1190          * Bump local count if this is first write after
1191          * connection failure with remote node.
1192          */
1193         ncomp = 1;
1194         rw_rlock(&hio_remote_lock[ncomp]);
1195         if (!ISCONNECTED(res, ncomp)) {
1196                 mtx_lock(&metadata_lock);
1197                 if (res->hr_primary_localcnt == res->hr_secondary_remotecnt) {
1198                         res->hr_primary_localcnt++;
1199                         pjdlog_debug(1, "Increasing localcnt to %ju.",
1200                             (uintmax_t)res->hr_primary_localcnt);
1201                         (void)metadata_write(res);
1202                 }
1203                 mtx_unlock(&metadata_lock);
1204         }
1205         rw_unlock(&hio_remote_lock[ncomp]);
1206         if (ioctl(res->hr_ggatefd, G_GATE_CMD_DONE, ggio) == -1)
1207                 primary_exit(EX_OSERR, "G_GATE_CMD_DONE failed");
1208         hio->hio_done = true;
1209 }
1210
1211 /*
1212  * Thread receives ggate I/O requests from the kernel and passes them to
1213  * appropriate threads:
1214  * WRITE - always goes to both local_send and remote_send threads
1215  * READ (when the block is up-to-date on local component) -
1216  *      only local_send thread
1217  * READ (when the block isn't up-to-date on local component) -
1218  *      only remote_send thread
1219  * DELETE - always goes to both local_send and remote_send threads
1220  * FLUSH - always goes to both local_send and remote_send threads
1221  */
1222 static void *
1223 ggate_recv_thread(void *arg)
1224 {
1225         struct hast_resource *res = arg;
1226         struct g_gate_ctl_io *ggio;
1227         struct hio *hio;
1228         unsigned int ii, ncomp, ncomps;
1229         int error;
1230
1231         for (;;) {
1232                 pjdlog_debug(2, "ggate_recv: Taking free request.");
1233                 QUEUE_TAKE2(hio, free);
1234                 pjdlog_debug(2, "ggate_recv: (%p) Got free request.", hio);
1235                 ggio = &hio->hio_ggio;
1236                 ggio->gctl_unit = res->hr_ggateunit;
1237                 ggio->gctl_length = MAXPHYS;
1238                 ggio->gctl_error = 0;
1239                 hio->hio_done = false;
1240                 hio->hio_replication = res->hr_replication;
1241                 pjdlog_debug(2,
1242                     "ggate_recv: (%p) Waiting for request from the kernel.",
1243                     hio);
1244                 if (ioctl(res->hr_ggatefd, G_GATE_CMD_START, ggio) == -1) {
1245                         if (sigexit_received)
1246                                 pthread_exit(NULL);
1247                         primary_exit(EX_OSERR, "G_GATE_CMD_START failed");
1248                 }
1249                 error = ggio->gctl_error;
1250                 switch (error) {
1251                 case 0:
1252                         break;
1253                 case ECANCELED:
1254                         /* Exit gracefully. */
1255                         if (!sigexit_received) {
1256                                 pjdlog_debug(2,
1257                                     "ggate_recv: (%p) Received cancel from the kernel.",
1258                                     hio);
1259                                 pjdlog_info("Received cancel from the kernel, exiting.");
1260                         }
1261                         pthread_exit(NULL);
1262                 case ENOMEM:
1263                         /*
1264                          * Buffer too small? Impossible, we allocate MAXPHYS
1265                          * bytes - request can't be bigger than that.
1266                          */
1267                         /* FALLTHROUGH */
1268                 case ENXIO:
1269                 default:
1270                         primary_exitx(EX_OSERR, "G_GATE_CMD_START failed: %s.",
1271                             strerror(error));
1272                 }
1273
1274                 ncomp = 0;
1275                 ncomps = HAST_NCOMPONENTS;
1276
1277                 for (ii = 0; ii < ncomps; ii++)
1278                         hio->hio_errors[ii] = EINVAL;
1279                 reqlog(LOG_DEBUG, 2, ggio,
1280                     "ggate_recv: (%p) Request received from the kernel: ",
1281                     hio);
1282
1283                 /*
1284                  * Inform all components about new write request.
1285                  * For read request prefer local component unless the given
1286                  * range is out-of-date, then use remote component.
1287                  */
1288                 switch (ggio->gctl_cmd) {
1289                 case BIO_READ:
1290                         res->hr_stat_read++;
1291                         ncomps = 1;
1292                         mtx_lock(&metadata_lock);
1293                         if (res->hr_syncsrc == HAST_SYNCSRC_UNDEF ||
1294                             res->hr_syncsrc == HAST_SYNCSRC_PRIMARY) {
1295                                 /*
1296                                  * This range is up-to-date on local component,
1297                                  * so handle request locally.
1298                                  */
1299                                  /* Local component is 0 for now. */
1300                                 ncomp = 0;
1301                         } else /* if (res->hr_syncsrc ==
1302                             HAST_SYNCSRC_SECONDARY) */ {
1303                                 PJDLOG_ASSERT(res->hr_syncsrc ==
1304                                     HAST_SYNCSRC_SECONDARY);
1305                                 /*
1306                                  * This range is out-of-date on local component,
1307                                  * so send request to the remote node.
1308                                  */
1309                                  /* Remote component is 1 for now. */
1310                                 ncomp = 1;
1311                         }
1312                         mtx_unlock(&metadata_lock);
1313                         break;
1314                 case BIO_WRITE:
1315                         res->hr_stat_write++;
1316                         if (res->hr_resuid == 0 &&
1317                             res->hr_primary_localcnt == 0) {
1318                                 /* This is first write. */
1319                                 res->hr_primary_localcnt = 1;
1320                         }
1321                         for (;;) {
1322                                 mtx_lock(&range_lock);
1323                                 if (rangelock_islocked(range_sync,
1324                                     ggio->gctl_offset, ggio->gctl_length)) {
1325                                         pjdlog_debug(2,
1326                                             "regular: Range offset=%jd length=%zu locked.",
1327                                             (intmax_t)ggio->gctl_offset,
1328                                             (size_t)ggio->gctl_length);
1329                                         range_regular_wait = true;
1330                                         cv_wait(&range_regular_cond, &range_lock);
1331                                         range_regular_wait = false;
1332                                         mtx_unlock(&range_lock);
1333                                         continue;
1334                                 }
1335                                 if (rangelock_add(range_regular,
1336                                     ggio->gctl_offset, ggio->gctl_length) == -1) {
1337                                         mtx_unlock(&range_lock);
1338                                         pjdlog_debug(2,
1339                                             "regular: Range offset=%jd length=%zu is already locked, waiting.",
1340                                             (intmax_t)ggio->gctl_offset,
1341                                             (size_t)ggio->gctl_length);
1342                                         sleep(1);
1343                                         continue;
1344                                 }
1345                                 mtx_unlock(&range_lock);
1346                                 break;
1347                         }
1348                         mtx_lock(&res->hr_amp_lock);
1349                         if (activemap_write_start(res->hr_amp,
1350                             ggio->gctl_offset, ggio->gctl_length)) {
1351                                 res->hr_stat_activemap_update++;
1352                                 (void)hast_activemap_flush(res);
1353                         } else {
1354                                 mtx_unlock(&res->hr_amp_lock);
1355                         }
1356                         if (ISMEMSYNC(hio)) {
1357                                 hio->hio_memsyncacked = false;
1358                                 refcnt_init(&hio->hio_writecount, ncomps);
1359                         }
1360                         break;
1361                 case BIO_DELETE:
1362                         res->hr_stat_delete++;
1363                         break;
1364                 case BIO_FLUSH:
1365                         res->hr_stat_flush++;
1366                         break;
1367                 }
1368                 pjdlog_debug(2,
1369                     "ggate_recv: (%p) Moving request to the send queues.", hio);
1370                 refcnt_init(&hio->hio_countdown, ncomps);
1371                 for (ii = ncomp; ii < ncomps; ii++)
1372                         QUEUE_INSERT1(hio, send, ii);
1373         }
1374         /* NOTREACHED */
1375         return (NULL);
1376 }
1377
1378 /*
1379  * Thread reads from or writes to local component.
1380  * If local read fails, it redirects it to remote_send thread.
1381  */
1382 static void *
1383 local_send_thread(void *arg)
1384 {
1385         struct hast_resource *res = arg;
1386         struct g_gate_ctl_io *ggio;
1387         struct hio *hio;
1388         unsigned int ncomp, rncomp;
1389         ssize_t ret;
1390
1391         /* Local component is 0 for now. */
1392         ncomp = 0;
1393         /* Remote component is 1 for now. */
1394         rncomp = 1;
1395
1396         for (;;) {
1397                 pjdlog_debug(2, "local_send: Taking request.");
1398                 QUEUE_TAKE1(hio, send, ncomp, 0);
1399                 pjdlog_debug(2, "local_send: (%p) Got request.", hio);
1400                 ggio = &hio->hio_ggio;
1401                 switch (ggio->gctl_cmd) {
1402                 case BIO_READ:
1403                         ret = pread(res->hr_localfd, ggio->gctl_data,
1404                             ggio->gctl_length,
1405                             ggio->gctl_offset + res->hr_localoff);
1406                         if (ret == ggio->gctl_length)
1407                                 hio->hio_errors[ncomp] = 0;
1408                         else if (!ISSYNCREQ(hio)) {
1409                                 /*
1410                                  * If READ failed, try to read from remote node.
1411                                  */
1412                                 if (ret == -1) {
1413                                         reqlog(LOG_WARNING, 0, ggio,
1414                                             "Local request failed (%s), trying remote node. ",
1415                                             strerror(errno));
1416                                 } else if (ret != ggio->gctl_length) {
1417                                         reqlog(LOG_WARNING, 0, ggio,
1418                                             "Local request failed (%zd != %jd), trying remote node. ",
1419                                             ret, (intmax_t)ggio->gctl_length);
1420                                 }
1421                                 QUEUE_INSERT1(hio, send, rncomp);
1422                                 continue;
1423                         }
1424                         break;
1425                 case BIO_WRITE:
1426                         ret = pwrite(res->hr_localfd, ggio->gctl_data,
1427                             ggio->gctl_length,
1428                             ggio->gctl_offset + res->hr_localoff);
1429                         if (ret == -1) {
1430                                 hio->hio_errors[ncomp] = errno;
1431                                 reqlog(LOG_WARNING, 0, ggio,
1432                                     "Local request failed (%s): ",
1433                                     strerror(errno));
1434                         } else if (ret != ggio->gctl_length) {
1435                                 hio->hio_errors[ncomp] = EIO;
1436                                 reqlog(LOG_WARNING, 0, ggio,
1437                                     "Local request failed (%zd != %jd): ",
1438                                     ret, (intmax_t)ggio->gctl_length);
1439                         } else {
1440                                 hio->hio_errors[ncomp] = 0;
1441                                 if (ISASYNC(hio)) {
1442                                         ggio->gctl_error = 0;
1443                                         write_complete(res, hio);
1444                                 }
1445                         }
1446                         break;
1447                 case BIO_DELETE:
1448                         ret = g_delete(res->hr_localfd,
1449                             ggio->gctl_offset + res->hr_localoff,
1450                             ggio->gctl_length);
1451                         if (ret == -1) {
1452                                 hio->hio_errors[ncomp] = errno;
1453                                 reqlog(LOG_WARNING, 0, ggio,
1454                                     "Local request failed (%s): ",
1455                                     strerror(errno));
1456                         } else {
1457                                 hio->hio_errors[ncomp] = 0;
1458                         }
1459                         break;
1460                 case BIO_FLUSH:
1461                         if (!res->hr_localflush) {
1462                                 ret = -1;
1463                                 errno = EOPNOTSUPP;
1464                                 break;
1465                         }
1466                         ret = g_flush(res->hr_localfd);
1467                         if (ret == -1) {
1468                                 if (errno == EOPNOTSUPP)
1469                                         res->hr_localflush = false;
1470                                 hio->hio_errors[ncomp] = errno;
1471                                 reqlog(LOG_WARNING, 0, ggio,
1472                                     "Local request failed (%s): ",
1473                                     strerror(errno));
1474                         } else {
1475                                 hio->hio_errors[ncomp] = 0;
1476                         }
1477                         break;
1478                 }
1479                 if (ISMEMSYNCWRITE(hio)) {
1480                         if (refcnt_release(&hio->hio_writecount) == 0) {
1481                                 write_complete(res, hio);
1482                         }
1483                 }
1484                 if (refcnt_release(&hio->hio_countdown) > 0)
1485                         continue;
1486                 if (ISSYNCREQ(hio)) {
1487                         mtx_lock(&sync_lock);
1488                         SYNCREQDONE(hio);
1489                         mtx_unlock(&sync_lock);
1490                         cv_signal(&sync_cond);
1491                 } else {
1492                         pjdlog_debug(2,
1493                             "local_send: (%p) Moving request to the done queue.",
1494                             hio);
1495                         QUEUE_INSERT2(hio, done);
1496                 }
1497         }
1498         /* NOTREACHED */
1499         return (NULL);
1500 }
1501
1502 static void
1503 keepalive_send(struct hast_resource *res, unsigned int ncomp)
1504 {
1505         struct nv *nv;
1506
1507         rw_rlock(&hio_remote_lock[ncomp]);
1508
1509         if (!ISCONNECTED(res, ncomp)) {
1510                 rw_unlock(&hio_remote_lock[ncomp]);
1511                 return;
1512         }
1513
1514         PJDLOG_ASSERT(res->hr_remotein != NULL);
1515         PJDLOG_ASSERT(res->hr_remoteout != NULL);
1516
1517         nv = nv_alloc();
1518         nv_add_uint8(nv, HIO_KEEPALIVE, "cmd");
1519         if (nv_error(nv) != 0) {
1520                 rw_unlock(&hio_remote_lock[ncomp]);
1521                 nv_free(nv);
1522                 pjdlog_debug(1,
1523                     "keepalive_send: Unable to prepare header to send.");
1524                 return;
1525         }
1526         if (hast_proto_send(res, res->hr_remoteout, nv, NULL, 0) == -1) {
1527                 rw_unlock(&hio_remote_lock[ncomp]);
1528                 pjdlog_common(LOG_DEBUG, 1, errno,
1529                     "keepalive_send: Unable to send request");
1530                 nv_free(nv);
1531                 remote_close(res, ncomp);
1532                 return;
1533         }
1534
1535         rw_unlock(&hio_remote_lock[ncomp]);
1536         nv_free(nv);
1537         pjdlog_debug(2, "keepalive_send: Request sent.");
1538 }
1539
1540 /*
1541  * Thread sends request to secondary node.
1542  */
1543 static void *
1544 remote_send_thread(void *arg)
1545 {
1546         struct hast_resource *res = arg;
1547         struct g_gate_ctl_io *ggio;
1548         time_t lastcheck, now;
1549         struct hio *hio;
1550         struct nv *nv;
1551         unsigned int ncomp;
1552         bool wakeup;
1553         uint64_t offset, length;
1554         uint8_t cmd;
1555         void *data;
1556
1557         /* Remote component is 1 for now. */
1558         ncomp = 1;
1559         lastcheck = time(NULL);
1560
1561         for (;;) {
1562                 pjdlog_debug(2, "remote_send: Taking request.");
1563                 QUEUE_TAKE1(hio, send, ncomp, HAST_KEEPALIVE);
1564                 if (hio == NULL) {
1565                         now = time(NULL);
1566                         if (lastcheck + HAST_KEEPALIVE <= now) {
1567                                 keepalive_send(res, ncomp);
1568                                 lastcheck = now;
1569                         }
1570                         continue;
1571                 }
1572                 pjdlog_debug(2, "remote_send: (%p) Got request.", hio);
1573                 ggio = &hio->hio_ggio;
1574                 switch (ggio->gctl_cmd) {
1575                 case BIO_READ:
1576                         cmd = HIO_READ;
1577                         data = NULL;
1578                         offset = ggio->gctl_offset;
1579                         length = ggio->gctl_length;
1580                         break;
1581                 case BIO_WRITE:
1582                         cmd = HIO_WRITE;
1583                         data = ggio->gctl_data;
1584                         offset = ggio->gctl_offset;
1585                         length = ggio->gctl_length;
1586                         break;
1587                 case BIO_DELETE:
1588                         cmd = HIO_DELETE;
1589                         data = NULL;
1590                         offset = ggio->gctl_offset;
1591                         length = ggio->gctl_length;
1592                         break;
1593                 case BIO_FLUSH:
1594                         cmd = HIO_FLUSH;
1595                         data = NULL;
1596                         offset = 0;
1597                         length = 0;
1598                         break;
1599                 default:
1600                         PJDLOG_ABORT("invalid condition");
1601                 }
1602                 nv = nv_alloc();
1603                 nv_add_uint8(nv, cmd, "cmd");
1604                 nv_add_uint64(nv, (uint64_t)ggio->gctl_seq, "seq");
1605                 nv_add_uint64(nv, offset, "offset");
1606                 nv_add_uint64(nv, length, "length");
1607                 if (ISMEMSYNCWRITE(hio))
1608                         nv_add_uint8(nv, 1, "memsync");
1609                 if (nv_error(nv) != 0) {
1610                         hio->hio_errors[ncomp] = nv_error(nv);
1611                         pjdlog_debug(2,
1612                             "remote_send: (%p) Unable to prepare header to send.",
1613                             hio);
1614                         reqlog(LOG_ERR, 0, ggio,
1615                             "Unable to prepare header to send (%s): ",
1616                             strerror(nv_error(nv)));
1617                         /* Move failed request immediately to the done queue. */
1618                         goto done_queue;
1619                 }
1620                 /*
1621                  * Protect connection from disappearing.
1622                  */
1623                 rw_rlock(&hio_remote_lock[ncomp]);
1624                 if (!ISCONNECTED(res, ncomp)) {
1625                         rw_unlock(&hio_remote_lock[ncomp]);
1626                         hio->hio_errors[ncomp] = ENOTCONN;
1627                         goto done_queue;
1628                 }
1629                 /*
1630                  * Move the request to recv queue before sending it, because
1631                  * in different order we can get reply before we move request
1632                  * to recv queue.
1633                  */
1634                 pjdlog_debug(2,
1635                     "remote_send: (%p) Moving request to the recv queue.",
1636                     hio);
1637                 mtx_lock(&hio_recv_list_lock[ncomp]);
1638                 wakeup = TAILQ_EMPTY(&hio_recv_list[ncomp]);
1639                 TAILQ_INSERT_TAIL(&hio_recv_list[ncomp], hio, hio_next[ncomp]);
1640                 hio_recv_list_size[ncomp]++;
1641                 mtx_unlock(&hio_recv_list_lock[ncomp]);
1642                 if (hast_proto_send(res, res->hr_remoteout, nv, data,
1643                     data != NULL ? length : 0) == -1) {
1644                         hio->hio_errors[ncomp] = errno;
1645                         rw_unlock(&hio_remote_lock[ncomp]);
1646                         pjdlog_debug(2,
1647                             "remote_send: (%p) Unable to send request.", hio);
1648                         reqlog(LOG_ERR, 0, ggio,
1649                             "Unable to send request (%s): ",
1650                             strerror(hio->hio_errors[ncomp]));
1651                         remote_close(res, ncomp);
1652                 } else {
1653                         rw_unlock(&hio_remote_lock[ncomp]);
1654                 }
1655                 nv_free(nv);
1656                 if (wakeup)
1657                         cv_signal(&hio_recv_list_cond[ncomp]);
1658                 continue;
1659 done_queue:
1660                 nv_free(nv);
1661                 if (ISSYNCREQ(hio)) {
1662                         if (refcnt_release(&hio->hio_countdown) > 0)
1663                                 continue;
1664                         mtx_lock(&sync_lock);
1665                         SYNCREQDONE(hio);
1666                         mtx_unlock(&sync_lock);
1667                         cv_signal(&sync_cond);
1668                         continue;
1669                 }
1670                 if (ggio->gctl_cmd == BIO_WRITE) {
1671                         mtx_lock(&res->hr_amp_lock);
1672                         if (activemap_need_sync(res->hr_amp, ggio->gctl_offset,
1673                             ggio->gctl_length)) {
1674                                 (void)hast_activemap_flush(res);
1675                         } else {
1676                                 mtx_unlock(&res->hr_amp_lock);
1677                         }
1678                         if (ISMEMSYNCWRITE(hio)) {
1679                                 if (refcnt_release(&hio->hio_writecount) == 0) {
1680                                         if (hio->hio_errors[0] == 0)
1681                                                 write_complete(res, hio);
1682                                 }
1683                         }
1684                 }
1685                 if (refcnt_release(&hio->hio_countdown) > 0)
1686                         continue;
1687                 pjdlog_debug(2,
1688                     "remote_send: (%p) Moving request to the done queue.",
1689                     hio);
1690                 QUEUE_INSERT2(hio, done);
1691         }
1692         /* NOTREACHED */
1693         return (NULL);
1694 }
1695
1696 /*
1697  * Thread receives answer from secondary node and passes it to ggate_send
1698  * thread.
1699  */
1700 static void *
1701 remote_recv_thread(void *arg)
1702 {
1703         struct hast_resource *res = arg;
1704         struct g_gate_ctl_io *ggio;
1705         struct hio *hio;
1706         struct nv *nv;
1707         unsigned int ncomp;
1708         uint64_t seq;
1709         bool memsyncack;
1710         int error;
1711
1712         /* Remote component is 1 for now. */
1713         ncomp = 1;
1714
1715         for (;;) {
1716                 /* Wait until there is anything to receive. */
1717                 mtx_lock(&hio_recv_list_lock[ncomp]);
1718                 while (TAILQ_EMPTY(&hio_recv_list[ncomp])) {
1719                         pjdlog_debug(2, "remote_recv: No requests, waiting.");
1720                         cv_wait(&hio_recv_list_cond[ncomp],
1721                             &hio_recv_list_lock[ncomp]);
1722                 }
1723                 mtx_unlock(&hio_recv_list_lock[ncomp]);
1724
1725                 memsyncack = false;
1726
1727                 rw_rlock(&hio_remote_lock[ncomp]);
1728                 if (!ISCONNECTED(res, ncomp)) {
1729                         rw_unlock(&hio_remote_lock[ncomp]);
1730                         /*
1731                          * Connection is dead, so move all pending requests to
1732                          * the done queue (one-by-one).
1733                          */
1734                         mtx_lock(&hio_recv_list_lock[ncomp]);
1735                         hio = TAILQ_FIRST(&hio_recv_list[ncomp]);
1736                         PJDLOG_ASSERT(hio != NULL);
1737                         TAILQ_REMOVE(&hio_recv_list[ncomp], hio,
1738                             hio_next[ncomp]);
1739                         hio_recv_list_size[ncomp]--;
1740                         mtx_unlock(&hio_recv_list_lock[ncomp]);
1741                         hio->hio_errors[ncomp] = ENOTCONN;
1742                         goto done_queue;
1743                 }
1744                 if (hast_proto_recv_hdr(res->hr_remotein, &nv) == -1) {
1745                         pjdlog_errno(LOG_ERR,
1746                             "Unable to receive reply header");
1747                         rw_unlock(&hio_remote_lock[ncomp]);
1748                         remote_close(res, ncomp);
1749                         continue;
1750                 }
1751                 rw_unlock(&hio_remote_lock[ncomp]);
1752                 seq = nv_get_uint64(nv, "seq");
1753                 if (seq == 0) {
1754                         pjdlog_error("Header contains no 'seq' field.");
1755                         nv_free(nv);
1756                         continue;
1757                 }
1758                 memsyncack = nv_exists(nv, "received");
1759                 mtx_lock(&hio_recv_list_lock[ncomp]);
1760                 TAILQ_FOREACH(hio, &hio_recv_list[ncomp], hio_next[ncomp]) {
1761                         if (hio->hio_ggio.gctl_seq == seq) {
1762                                 TAILQ_REMOVE(&hio_recv_list[ncomp], hio,
1763                                     hio_next[ncomp]);
1764                                 hio_recv_list_size[ncomp]--;
1765                                 break;
1766                         }
1767                 }
1768                 mtx_unlock(&hio_recv_list_lock[ncomp]);
1769                 if (hio == NULL) {
1770                         pjdlog_error("Found no request matching received 'seq' field (%ju).",
1771                             (uintmax_t)seq);
1772                         nv_free(nv);
1773                         continue;
1774                 }
1775                 ggio = &hio->hio_ggio;
1776                 error = nv_get_int16(nv, "error");
1777                 if (error != 0) {
1778                         /* Request failed on remote side. */
1779                         hio->hio_errors[ncomp] = error;
1780                         reqlog(LOG_WARNING, 0, ggio,
1781                             "Remote request failed (%s): ", strerror(error));
1782                         nv_free(nv);
1783                         goto done_queue;
1784                 }
1785                 switch (ggio->gctl_cmd) {
1786                 case BIO_READ:
1787                         rw_rlock(&hio_remote_lock[ncomp]);
1788                         if (!ISCONNECTED(res, ncomp)) {
1789                                 rw_unlock(&hio_remote_lock[ncomp]);
1790                                 nv_free(nv);
1791                                 goto done_queue;
1792                         }
1793                         if (hast_proto_recv_data(res, res->hr_remotein, nv,
1794                             ggio->gctl_data, ggio->gctl_length) == -1) {
1795                                 hio->hio_errors[ncomp] = errno;
1796                                 pjdlog_errno(LOG_ERR,
1797                                     "Unable to receive reply data");
1798                                 rw_unlock(&hio_remote_lock[ncomp]);
1799                                 nv_free(nv);
1800                                 remote_close(res, ncomp);
1801                                 goto done_queue;
1802                         }
1803                         rw_unlock(&hio_remote_lock[ncomp]);
1804                         break;
1805                 case BIO_WRITE:
1806                 case BIO_DELETE:
1807                 case BIO_FLUSH:
1808                         break;
1809                 default:
1810                         PJDLOG_ABORT("invalid condition");
1811                 }
1812                 hio->hio_errors[ncomp] = 0;
1813                 nv_free(nv);
1814 done_queue:
1815                 if (ISMEMSYNCWRITE(hio)) {
1816                         if (!hio->hio_memsyncacked) {
1817                                 PJDLOG_ASSERT(memsyncack ||
1818                                     hio->hio_errors[ncomp] != 0);
1819                                 /* Remote ack arrived. */
1820                                 if (refcnt_release(&hio->hio_writecount) == 0) {
1821                                         if (hio->hio_errors[0] == 0)
1822                                                 write_complete(res, hio);
1823                                 }
1824                                 hio->hio_memsyncacked = true;
1825                                 if (hio->hio_errors[ncomp] == 0) {
1826                                         pjdlog_debug(2,
1827                                             "remote_recv: (%p) Moving request "
1828                                             "back to the recv queue.", hio);
1829                                         mtx_lock(&hio_recv_list_lock[ncomp]);
1830                                         TAILQ_INSERT_TAIL(&hio_recv_list[ncomp],
1831                                             hio, hio_next[ncomp]);
1832                                         hio_recv_list_size[ncomp]++;
1833                                         mtx_unlock(&hio_recv_list_lock[ncomp]);
1834                                         continue;
1835                                 }
1836                         } else {
1837                                 PJDLOG_ASSERT(!memsyncack);
1838                                 /* Remote final reply arrived. */
1839                         }
1840                 }
1841                 if (refcnt_release(&hio->hio_countdown) > 0)
1842                         continue;
1843                 if (ISSYNCREQ(hio)) {
1844                         mtx_lock(&sync_lock);
1845                         SYNCREQDONE(hio);
1846                         mtx_unlock(&sync_lock);
1847                         cv_signal(&sync_cond);
1848                 } else {
1849                         pjdlog_debug(2,
1850                             "remote_recv: (%p) Moving request to the done queue.",
1851                             hio);
1852                         QUEUE_INSERT2(hio, done);
1853                 }
1854         }
1855         /* NOTREACHED */
1856         return (NULL);
1857 }
1858
1859 /*
1860  * Thread sends answer to the kernel.
1861  */
1862 static void *
1863 ggate_send_thread(void *arg)
1864 {
1865         struct hast_resource *res = arg;
1866         struct g_gate_ctl_io *ggio;
1867         struct hio *hio;
1868         unsigned int ii, ncomps;
1869
1870         ncomps = HAST_NCOMPONENTS;
1871
1872         for (;;) {
1873                 pjdlog_debug(2, "ggate_send: Taking request.");
1874                 QUEUE_TAKE2(hio, done);
1875                 pjdlog_debug(2, "ggate_send: (%p) Got request.", hio);
1876                 ggio = &hio->hio_ggio;
1877                 for (ii = 0; ii < ncomps; ii++) {
1878                         if (hio->hio_errors[ii] == 0) {
1879                                 /*
1880                                  * One successful request is enough to declare
1881                                  * success.
1882                                  */
1883                                 ggio->gctl_error = 0;
1884                                 break;
1885                         }
1886                 }
1887                 if (ii == ncomps) {
1888                         /*
1889                          * None of the requests were successful.
1890                          * Use the error from local component except the
1891                          * case when we did only remote request.
1892                          */
1893                         if (ggio->gctl_cmd == BIO_READ &&
1894                             res->hr_syncsrc == HAST_SYNCSRC_SECONDARY)
1895                                 ggio->gctl_error = hio->hio_errors[1];
1896                         else
1897                                 ggio->gctl_error = hio->hio_errors[0];
1898                 }
1899                 if (ggio->gctl_error == 0 && ggio->gctl_cmd == BIO_WRITE) {
1900                         mtx_lock(&res->hr_amp_lock);
1901                         if (activemap_write_complete(res->hr_amp,
1902                             ggio->gctl_offset, ggio->gctl_length)) {
1903                                 res->hr_stat_activemap_update++;
1904                                 (void)hast_activemap_flush(res);
1905                         } else {
1906                                 mtx_unlock(&res->hr_amp_lock);
1907                         }
1908                 }
1909                 if (ggio->gctl_cmd == BIO_WRITE) {
1910                         /*
1911                          * Unlock range we locked.
1912                          */
1913                         mtx_lock(&range_lock);
1914                         rangelock_del(range_regular, ggio->gctl_offset,
1915                             ggio->gctl_length);
1916                         if (range_sync_wait)
1917                                 cv_signal(&range_sync_cond);
1918                         mtx_unlock(&range_lock);
1919                         if (!hio->hio_done)
1920                                 write_complete(res, hio);
1921                 } else {
1922                         if (ioctl(res->hr_ggatefd, G_GATE_CMD_DONE, ggio) == -1) {
1923                                 primary_exit(EX_OSERR,
1924                                     "G_GATE_CMD_DONE failed");
1925                         }
1926                 }
1927                 if (hio->hio_errors[0]) {
1928                         switch (ggio->gctl_cmd) {
1929                         case BIO_READ:
1930                                 res->hr_stat_read_error++;
1931                                 break;
1932                         case BIO_WRITE:
1933                                 res->hr_stat_write_error++;
1934                                 break;
1935                         case BIO_DELETE:
1936                                 res->hr_stat_delete_error++;
1937                                 break;
1938                         case BIO_FLUSH:
1939                                 res->hr_stat_flush_error++;
1940                                 break;
1941                         }
1942                 }
1943                 pjdlog_debug(2,
1944                     "ggate_send: (%p) Moving request to the free queue.", hio);
1945                 QUEUE_INSERT2(hio, free);
1946         }
1947         /* NOTREACHED */
1948         return (NULL);
1949 }
1950
1951 /*
1952  * Thread synchronize local and remote components.
1953  */
1954 static void *
1955 sync_thread(void *arg __unused)
1956 {
1957         struct hast_resource *res = arg;
1958         struct hio *hio;
1959         struct g_gate_ctl_io *ggio;
1960         struct timeval tstart, tend, tdiff;
1961         unsigned int ii, ncomp, ncomps;
1962         off_t offset, length, synced;
1963         bool dorewind, directreads;
1964         int syncext;
1965
1966         ncomps = HAST_NCOMPONENTS;
1967         dorewind = true;
1968         synced = 0;
1969         offset = -1;
1970         directreads = false;
1971
1972         for (;;) {
1973                 mtx_lock(&sync_lock);
1974                 if (offset >= 0 && !sync_inprogress) {
1975                         gettimeofday(&tend, NULL);
1976                         timersub(&tend, &tstart, &tdiff);
1977                         pjdlog_info("Synchronization interrupted after %#.0T. "
1978                             "%NB synchronized so far.", &tdiff,
1979                             (intmax_t)synced);
1980                         event_send(res, EVENT_SYNCINTR);
1981                 }
1982                 while (!sync_inprogress) {
1983                         dorewind = true;
1984                         synced = 0;
1985                         cv_wait(&sync_cond, &sync_lock);
1986                 }
1987                 mtx_unlock(&sync_lock);
1988                 /*
1989                  * Obtain offset at which we should synchronize.
1990                  * Rewind synchronization if needed.
1991                  */
1992                 mtx_lock(&res->hr_amp_lock);
1993                 if (dorewind)
1994                         activemap_sync_rewind(res->hr_amp);
1995                 offset = activemap_sync_offset(res->hr_amp, &length, &syncext);
1996                 if (syncext != -1) {
1997                         /*
1998                          * We synchronized entire syncext extent, we can mark
1999                          * it as clean now.
2000                          */
2001                         if (activemap_extent_complete(res->hr_amp, syncext))
2002                                 (void)hast_activemap_flush(res);
2003                         else
2004                                 mtx_unlock(&res->hr_amp_lock);
2005                 } else {
2006                         mtx_unlock(&res->hr_amp_lock);
2007                 }
2008                 if (dorewind) {
2009                         dorewind = false;
2010                         if (offset == -1)
2011                                 pjdlog_info("Nodes are in sync.");
2012                         else {
2013                                 pjdlog_info("Synchronization started. %NB to go.",
2014                                     (intmax_t)(res->hr_extentsize *
2015                                     activemap_ndirty(res->hr_amp)));
2016                                 event_send(res, EVENT_SYNCSTART);
2017                                 gettimeofday(&tstart, NULL);
2018                         }
2019                 }
2020                 if (offset == -1) {
2021                         sync_stop();
2022                         pjdlog_debug(1, "Nothing to synchronize.");
2023                         /*
2024                          * Synchronization complete, make both localcnt and
2025                          * remotecnt equal.
2026                          */
2027                         ncomp = 1;
2028                         rw_rlock(&hio_remote_lock[ncomp]);
2029                         if (ISCONNECTED(res, ncomp)) {
2030                                 if (synced > 0) {
2031                                         int64_t bps;
2032
2033                                         gettimeofday(&tend, NULL);
2034                                         timersub(&tend, &tstart, &tdiff);
2035                                         bps = (int64_t)((double)synced /
2036                                             ((double)tdiff.tv_sec +
2037                                             (double)tdiff.tv_usec / 1000000));
2038                                         pjdlog_info("Synchronization complete. "
2039                                             "%NB synchronized in %#.0lT (%NB/sec).",
2040                                             (intmax_t)synced, &tdiff,
2041                                             (intmax_t)bps);
2042                                         event_send(res, EVENT_SYNCDONE);
2043                                 }
2044                                 mtx_lock(&metadata_lock);
2045                                 if (res->hr_syncsrc == HAST_SYNCSRC_SECONDARY)
2046                                         directreads = true;
2047                                 res->hr_syncsrc = HAST_SYNCSRC_UNDEF;
2048                                 res->hr_primary_localcnt =
2049                                     res->hr_secondary_remotecnt;
2050                                 res->hr_primary_remotecnt =
2051                                     res->hr_secondary_localcnt;
2052                                 pjdlog_debug(1,
2053                                     "Setting localcnt to %ju and remotecnt to %ju.",
2054                                     (uintmax_t)res->hr_primary_localcnt,
2055                                     (uintmax_t)res->hr_primary_remotecnt);
2056                                 (void)metadata_write(res);
2057                                 mtx_unlock(&metadata_lock);
2058                         }
2059                         rw_unlock(&hio_remote_lock[ncomp]);
2060                         if (directreads) {
2061                                 directreads = false;
2062                                 enable_direct_reads(res);
2063                         }
2064                         continue;
2065                 }
2066                 pjdlog_debug(2, "sync: Taking free request.");
2067                 QUEUE_TAKE2(hio, free);
2068                 pjdlog_debug(2, "sync: (%p) Got free request.", hio);
2069                 /*
2070                  * Lock the range we are going to synchronize. We don't want
2071                  * race where someone writes between our read and write.
2072                  */
2073                 for (;;) {
2074                         mtx_lock(&range_lock);
2075                         if (rangelock_islocked(range_regular, offset, length)) {
2076                                 pjdlog_debug(2,
2077                                     "sync: Range offset=%jd length=%jd locked.",
2078                                     (intmax_t)offset, (intmax_t)length);
2079                                 range_sync_wait = true;
2080                                 cv_wait(&range_sync_cond, &range_lock);
2081                                 range_sync_wait = false;
2082                                 mtx_unlock(&range_lock);
2083                                 continue;
2084                         }
2085                         if (rangelock_add(range_sync, offset, length) == -1) {
2086                                 mtx_unlock(&range_lock);
2087                                 pjdlog_debug(2,
2088                                     "sync: Range offset=%jd length=%jd is already locked, waiting.",
2089                                     (intmax_t)offset, (intmax_t)length);
2090                                 sleep(1);
2091                                 continue;
2092                         }
2093                         mtx_unlock(&range_lock);
2094                         break;
2095                 }
2096                 /*
2097                  * First read the data from synchronization source.
2098                  */
2099                 SYNCREQ(hio);
2100                 ggio = &hio->hio_ggio;
2101                 ggio->gctl_cmd = BIO_READ;
2102                 ggio->gctl_offset = offset;
2103                 ggio->gctl_length = length;
2104                 ggio->gctl_error = 0;
2105                 hio->hio_done = false;
2106                 hio->hio_replication = res->hr_replication;
2107                 for (ii = 0; ii < ncomps; ii++)
2108                         hio->hio_errors[ii] = EINVAL;
2109                 reqlog(LOG_DEBUG, 2, ggio, "sync: (%p) Sending sync request: ",
2110                     hio);
2111                 pjdlog_debug(2, "sync: (%p) Moving request to the send queue.",
2112                     hio);
2113                 mtx_lock(&metadata_lock);
2114                 if (res->hr_syncsrc == HAST_SYNCSRC_PRIMARY) {
2115                         /*
2116                          * This range is up-to-date on local component,
2117                          * so handle request locally.
2118                          */
2119                          /* Local component is 0 for now. */
2120                         ncomp = 0;
2121                 } else /* if (res->hr_syncsrc == HAST_SYNCSRC_SECONDARY) */ {
2122                         PJDLOG_ASSERT(res->hr_syncsrc == HAST_SYNCSRC_SECONDARY);
2123                         /*
2124                          * This range is out-of-date on local component,
2125                          * so send request to the remote node.
2126                          */
2127                          /* Remote component is 1 for now. */
2128                         ncomp = 1;
2129                 }
2130                 mtx_unlock(&metadata_lock);
2131                 refcnt_init(&hio->hio_countdown, 1);
2132                 QUEUE_INSERT1(hio, send, ncomp);
2133
2134                 /*
2135                  * Let's wait for READ to finish.
2136                  */
2137                 mtx_lock(&sync_lock);
2138                 while (!ISSYNCREQDONE(hio))
2139                         cv_wait(&sync_cond, &sync_lock);
2140                 mtx_unlock(&sync_lock);
2141
2142                 if (hio->hio_errors[ncomp] != 0) {
2143                         pjdlog_error("Unable to read synchronization data: %s.",
2144                             strerror(hio->hio_errors[ncomp]));
2145                         goto free_queue;
2146                 }
2147
2148                 /*
2149                  * We read the data from synchronization source, now write it
2150                  * to synchronization target.
2151                  */
2152                 SYNCREQ(hio);
2153                 ggio->gctl_cmd = BIO_WRITE;
2154                 for (ii = 0; ii < ncomps; ii++)
2155                         hio->hio_errors[ii] = EINVAL;
2156                 reqlog(LOG_DEBUG, 2, ggio, "sync: (%p) Sending sync request: ",
2157                     hio);
2158                 pjdlog_debug(2, "sync: (%p) Moving request to the send queue.",
2159                     hio);
2160                 mtx_lock(&metadata_lock);
2161                 if (res->hr_syncsrc == HAST_SYNCSRC_PRIMARY) {
2162                         /*
2163                          * This range is up-to-date on local component,
2164                          * so we update remote component.
2165                          */
2166                          /* Remote component is 1 for now. */
2167                         ncomp = 1;
2168                 } else /* if (res->hr_syncsrc == HAST_SYNCSRC_SECONDARY) */ {
2169                         PJDLOG_ASSERT(res->hr_syncsrc == HAST_SYNCSRC_SECONDARY);
2170                         /*
2171                          * This range is out-of-date on local component,
2172                          * so we update it.
2173                          */
2174                          /* Local component is 0 for now. */
2175                         ncomp = 0;
2176                 }
2177                 mtx_unlock(&metadata_lock);
2178
2179                 pjdlog_debug(2, "sync: (%p) Moving request to the send queue.",
2180                     hio);
2181                 refcnt_init(&hio->hio_countdown, 1);
2182                 QUEUE_INSERT1(hio, send, ncomp);
2183
2184                 /*
2185                  * Let's wait for WRITE to finish.
2186                  */
2187                 mtx_lock(&sync_lock);
2188                 while (!ISSYNCREQDONE(hio))
2189                         cv_wait(&sync_cond, &sync_lock);
2190                 mtx_unlock(&sync_lock);
2191
2192                 if (hio->hio_errors[ncomp] != 0) {
2193                         pjdlog_error("Unable to write synchronization data: %s.",
2194                             strerror(hio->hio_errors[ncomp]));
2195                         goto free_queue;
2196                 }
2197
2198                 synced += length;
2199 free_queue:
2200                 mtx_lock(&range_lock);
2201                 rangelock_del(range_sync, offset, length);
2202                 if (range_regular_wait)
2203                         cv_signal(&range_regular_cond);
2204                 mtx_unlock(&range_lock);
2205                 pjdlog_debug(2, "sync: (%p) Moving request to the free queue.",
2206                     hio);
2207                 QUEUE_INSERT2(hio, free);
2208         }
2209         /* NOTREACHED */
2210         return (NULL);
2211 }
2212
2213 void
2214 primary_config_reload(struct hast_resource *res, struct nv *nv)
2215 {
2216         unsigned int ii, ncomps;
2217         int modified, vint;
2218         const char *vstr;
2219
2220         pjdlog_info("Reloading configuration...");
2221
2222         PJDLOG_ASSERT(res->hr_role == HAST_ROLE_PRIMARY);
2223         PJDLOG_ASSERT(gres == res);
2224         nv_assert(nv, "remoteaddr");
2225         nv_assert(nv, "sourceaddr");
2226         nv_assert(nv, "replication");
2227         nv_assert(nv, "checksum");
2228         nv_assert(nv, "compression");
2229         nv_assert(nv, "timeout");
2230         nv_assert(nv, "exec");
2231         nv_assert(nv, "metaflush");
2232
2233         ncomps = HAST_NCOMPONENTS;
2234
2235 #define MODIFIED_REMOTEADDR     0x01
2236 #define MODIFIED_SOURCEADDR     0x02
2237 #define MODIFIED_REPLICATION    0x04
2238 #define MODIFIED_CHECKSUM       0x08
2239 #define MODIFIED_COMPRESSION    0x10
2240 #define MODIFIED_TIMEOUT        0x20
2241 #define MODIFIED_EXEC           0x40
2242 #define MODIFIED_METAFLUSH      0x80
2243         modified = 0;
2244
2245         vstr = nv_get_string(nv, "remoteaddr");
2246         if (strcmp(gres->hr_remoteaddr, vstr) != 0) {
2247                 /*
2248                  * Don't copy res->hr_remoteaddr to gres just yet.
2249                  * We want remote_close() to log disconnect from the old
2250                  * addresses, not from the new ones.
2251                  */
2252                 modified |= MODIFIED_REMOTEADDR;
2253         }
2254         vstr = nv_get_string(nv, "sourceaddr");
2255         if (strcmp(gres->hr_sourceaddr, vstr) != 0) {
2256                 strlcpy(gres->hr_sourceaddr, vstr, sizeof(gres->hr_sourceaddr));
2257                 modified |= MODIFIED_SOURCEADDR;
2258         }
2259         vint = nv_get_int32(nv, "replication");
2260         if (gres->hr_replication != vint) {
2261                 gres->hr_replication = vint;
2262                 modified |= MODIFIED_REPLICATION;
2263         }
2264         vint = nv_get_int32(nv, "checksum");
2265         if (gres->hr_checksum != vint) {
2266                 gres->hr_checksum = vint;
2267                 modified |= MODIFIED_CHECKSUM;
2268         }
2269         vint = nv_get_int32(nv, "compression");
2270         if (gres->hr_compression != vint) {
2271                 gres->hr_compression = vint;
2272                 modified |= MODIFIED_COMPRESSION;
2273         }
2274         vint = nv_get_int32(nv, "timeout");
2275         if (gres->hr_timeout != vint) {
2276                 gres->hr_timeout = vint;
2277                 modified |= MODIFIED_TIMEOUT;
2278         }
2279         vstr = nv_get_string(nv, "exec");
2280         if (strcmp(gres->hr_exec, vstr) != 0) {
2281                 strlcpy(gres->hr_exec, vstr, sizeof(gres->hr_exec));
2282                 modified |= MODIFIED_EXEC;
2283         }
2284         vint = nv_get_int32(nv, "metaflush");
2285         if (gres->hr_metaflush != vint) {
2286                 gres->hr_metaflush = vint;
2287                 modified |= MODIFIED_METAFLUSH;
2288         }
2289
2290         /*
2291          * Change timeout for connected sockets.
2292          * Don't bother if we need to reconnect.
2293          */
2294         if ((modified & MODIFIED_TIMEOUT) != 0 &&
2295             (modified & (MODIFIED_REMOTEADDR | MODIFIED_SOURCEADDR)) == 0) {
2296                 for (ii = 0; ii < ncomps; ii++) {
2297                         if (!ISREMOTE(ii))
2298                                 continue;
2299                         rw_rlock(&hio_remote_lock[ii]);
2300                         if (!ISCONNECTED(gres, ii)) {
2301                                 rw_unlock(&hio_remote_lock[ii]);
2302                                 continue;
2303                         }
2304                         rw_unlock(&hio_remote_lock[ii]);
2305                         if (proto_timeout(gres->hr_remotein,
2306                             gres->hr_timeout) == -1) {
2307                                 pjdlog_errno(LOG_WARNING,
2308                                     "Unable to set connection timeout");
2309                         }
2310                         if (proto_timeout(gres->hr_remoteout,
2311                             gres->hr_timeout) == -1) {
2312                                 pjdlog_errno(LOG_WARNING,
2313                                     "Unable to set connection timeout");
2314                         }
2315                 }
2316         }
2317         if ((modified & (MODIFIED_REMOTEADDR | MODIFIED_SOURCEADDR)) != 0) {
2318                 for (ii = 0; ii < ncomps; ii++) {
2319                         if (!ISREMOTE(ii))
2320                                 continue;
2321                         remote_close(gres, ii);
2322                 }
2323                 if (modified & MODIFIED_REMOTEADDR) {
2324                         vstr = nv_get_string(nv, "remoteaddr");
2325                         strlcpy(gres->hr_remoteaddr, vstr,
2326                             sizeof(gres->hr_remoteaddr));
2327                 }
2328         }
2329 #undef  MODIFIED_REMOTEADDR
2330 #undef  MODIFIED_SOURCEADDR
2331 #undef  MODIFIED_REPLICATION
2332 #undef  MODIFIED_CHECKSUM
2333 #undef  MODIFIED_COMPRESSION
2334 #undef  MODIFIED_TIMEOUT
2335 #undef  MODIFIED_EXEC
2336 #undef  MODIFIED_METAFLUSH
2337
2338         pjdlog_info("Configuration reloaded successfully.");
2339 }
2340
2341 static void
2342 guard_one(struct hast_resource *res, unsigned int ncomp)
2343 {
2344         struct proto_conn *in, *out;
2345
2346         if (!ISREMOTE(ncomp))
2347                 return;
2348
2349         rw_rlock(&hio_remote_lock[ncomp]);
2350
2351         if (!real_remote(res)) {
2352                 rw_unlock(&hio_remote_lock[ncomp]);
2353                 return;
2354         }
2355
2356         if (ISCONNECTED(res, ncomp)) {
2357                 PJDLOG_ASSERT(res->hr_remotein != NULL);
2358                 PJDLOG_ASSERT(res->hr_remoteout != NULL);
2359                 rw_unlock(&hio_remote_lock[ncomp]);
2360                 pjdlog_debug(2, "remote_guard: Connection to %s is ok.",
2361                     res->hr_remoteaddr);
2362                 return;
2363         }
2364
2365         PJDLOG_ASSERT(res->hr_remotein == NULL);
2366         PJDLOG_ASSERT(res->hr_remoteout == NULL);
2367         /*
2368          * Upgrade the lock. It doesn't have to be atomic as no other thread
2369          * can change connection status from disconnected to connected.
2370          */
2371         rw_unlock(&hio_remote_lock[ncomp]);
2372         pjdlog_debug(2, "remote_guard: Reconnecting to %s.",
2373             res->hr_remoteaddr);
2374         in = out = NULL;
2375         if (init_remote(res, &in, &out) == 0) {
2376                 rw_wlock(&hio_remote_lock[ncomp]);
2377                 PJDLOG_ASSERT(res->hr_remotein == NULL);
2378                 PJDLOG_ASSERT(res->hr_remoteout == NULL);
2379                 PJDLOG_ASSERT(in != NULL && out != NULL);
2380                 res->hr_remotein = in;
2381                 res->hr_remoteout = out;
2382                 rw_unlock(&hio_remote_lock[ncomp]);
2383                 pjdlog_info("Successfully reconnected to %s.",
2384                     res->hr_remoteaddr);
2385                 sync_start();
2386         } else {
2387                 /* Both connections should be NULL. */
2388                 PJDLOG_ASSERT(res->hr_remotein == NULL);
2389                 PJDLOG_ASSERT(res->hr_remoteout == NULL);
2390                 PJDLOG_ASSERT(in == NULL && out == NULL);
2391                 pjdlog_debug(2, "remote_guard: Reconnect to %s failed.",
2392                     res->hr_remoteaddr);
2393         }
2394 }
2395
2396 /*
2397  * Thread guards remote connections and reconnects when needed, handles
2398  * signals, etc.
2399  */
2400 static void *
2401 guard_thread(void *arg)
2402 {
2403         struct hast_resource *res = arg;
2404         unsigned int ii, ncomps;
2405         struct timespec timeout;
2406         time_t lastcheck, now;
2407         sigset_t mask;
2408         int signo;
2409
2410         ncomps = HAST_NCOMPONENTS;
2411         lastcheck = time(NULL);
2412
2413         PJDLOG_VERIFY(sigemptyset(&mask) == 0);
2414         PJDLOG_VERIFY(sigaddset(&mask, SIGINT) == 0);
2415         PJDLOG_VERIFY(sigaddset(&mask, SIGTERM) == 0);
2416
2417         timeout.tv_sec = HAST_KEEPALIVE;
2418         timeout.tv_nsec = 0;
2419         signo = -1;
2420
2421         for (;;) {
2422                 switch (signo) {
2423                 case SIGINT:
2424                 case SIGTERM:
2425                         sigexit_received = true;
2426                         primary_exitx(EX_OK,
2427                             "Termination signal received, exiting.");
2428                         break;
2429                 default:
2430                         break;
2431                 }
2432
2433                 /*
2434                  * Don't check connections until we fully started,
2435                  * as we may still be looping, waiting for remote node
2436                  * to switch from primary to secondary.
2437                  */
2438                 if (fullystarted) {
2439                         pjdlog_debug(2, "remote_guard: Checking connections.");
2440                         now = time(NULL);
2441                         if (lastcheck + HAST_KEEPALIVE <= now) {
2442                                 for (ii = 0; ii < ncomps; ii++)
2443                                         guard_one(res, ii);
2444                                 lastcheck = now;
2445                         }
2446                 }
2447                 signo = sigtimedwait(&mask, NULL, &timeout);
2448         }
2449         /* NOTREACHED */
2450         return (NULL);
2451 }