sbin/hastd/secondary.c

   1 /*-
   2  * Copyright (c) 2009-2010 The FreeBSD Foundation
   3  * Copyright (c) 2010 Pawel Jakub Dawidek <pjd@FreeBSD.org>
   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/param.h>
  35 #include <sys/time.h>
  36 #include <sys/bio.h>
  37 #include <sys/disk.h>
  38 #include <sys/stat.h>
  39
  40 #include <err.h>
  41 #include <errno.h>
  42 #include <fcntl.h>
  43 #include <libgeom.h>
  44 #include <pthread.h>
  45 #include <signal.h>
  46 #include <stdint.h>
  47 #include <stdio.h>
  48 #include <string.h>
  49 #include <sysexits.h>
  50 #include <unistd.h>
  51
  52 #include <activemap.h>
  53 #include <nv.h>
  54 #include <pjdlog.h>
  55
  56 #include "control.h"
  57 #include "event.h"
  58 #include "hast.h"
  59 #include "hast_proto.h"
  60 #include "hastd.h"
  61 #include "hooks.h"
  62 #include "metadata.h"
  63 #include "proto.h"
  64 #include "subr.h"
  65 #include "synch.h"
  66
  67 struct hio {
  68         uint64_t         hio_seq;
  69         int              hio_error;
  70         void            *hio_data;
  71         uint8_t          hio_cmd;
  72         uint64_t         hio_offset;
  73         uint64_t         hio_length;
  74         bool             hio_memsync;
  75         TAILQ_ENTRY(hio) hio_next;
  76 };
  77
  78 static struct hast_resource *gres;
  79
  80 /*
  81  * Free list holds unused structures. When free list is empty, we have to wait
  82  * until some in-progress requests are freed.
  83  */
  84 static TAILQ_HEAD(, hio) hio_free_list;
  85 static size_t hio_free_list_size;
  86 static pthread_mutex_t hio_free_list_lock;
  87 static pthread_cond_t hio_free_list_cond;
  88 /*
  89  * Disk thread (the one that does I/O requests) takes requests from this list.
  90  */
  91 static TAILQ_HEAD(, hio) hio_disk_list;
  92 static size_t hio_disk_list_size;
  93 static pthread_mutex_t hio_disk_list_lock;
  94 static pthread_cond_t hio_disk_list_cond;
  95 /*
  96  * Thread that sends requests back to primary takes requests from this list.
  97  */
  98 static TAILQ_HEAD(, hio) hio_send_list;
  99 static size_t hio_send_list_size;
 100 static pthread_mutex_t hio_send_list_lock;
 101 static pthread_cond_t hio_send_list_cond;
 102
 103 /*
 104  * Maximum number of outstanding I/O requests.
 105  */
 106 #define HAST_HIO_MAX    256
 107
 108 static void *recv_thread(void *arg);
 109 static void *disk_thread(void *arg);
 110 static void *send_thread(void *arg);
 111
 112 #define QUEUE_INSERT(name, hio) do {                                    \
 113         mtx_lock(&hio_##name##_list_lock);                              \
 114         if (TAILQ_EMPTY(&hio_##name##_list))                            \
 115                 cv_broadcast(&hio_##name##_list_cond);                  \
 116         TAILQ_INSERT_TAIL(&hio_##name##_list, (hio), hio_next);         \
 117         hio_##name##_list_size++;                                       \
 118         mtx_unlock(&hio_##name##_list_lock);                            \
 119 } while (0)
 120 #define QUEUE_TAKE(name, hio)   do {                                    \
 121         mtx_lock(&hio_##name##_list_lock);                              \
 122         while (((hio) = TAILQ_FIRST(&hio_##name##_list)) == NULL) {     \
 123                 cv_wait(&hio_##name##_list_cond,                        \
 124                     &hio_##name##_list_lock);                           \
 125         }                                                               \
 126         PJDLOG_ASSERT(hio_##name##_list_size != 0);                     \
 127         hio_##name##_list_size--;                                       \
 128         TAILQ_REMOVE(&hio_##name##_list, (hio), hio_next);              \
 129         mtx_unlock(&hio_##name##_list_lock);                            \
 130 } while (0)
 131
 132 static void
 133 output_status_aux(struct nv *nvout)
 134 {
 135
 136         nv_add_uint64(nvout, (uint64_t)hio_free_list_size, "idle_queue_size");
 137         nv_add_uint64(nvout, (uint64_t)hio_disk_list_size, "local_queue_size");
 138         nv_add_uint64(nvout, (uint64_t)hio_send_list_size, "send_queue_size");
 139 }
 140
 141 static void
 142 hio_clear(struct hio *hio)
 143 {
 144
 145         hio->hio_seq = 0;
 146         hio->hio_error = 0;
 147         hio->hio_cmd = HIO_UNDEF;
 148         hio->hio_offset = 0;
 149         hio->hio_length = 0;
 150         hio->hio_memsync = false;
 151 }
 152
 153 static void
 154 hio_copy(const struct hio *srchio, struct hio *dsthio)
 155 {
 156
 157         /*
 158          * We don't copy hio_error, hio_data and hio_next fields.
 159          */
 160
 161         dsthio->hio_seq = srchio->hio_seq;
 162         dsthio->hio_cmd = srchio->hio_cmd;
 163         dsthio->hio_offset = srchio->hio_offset;
 164         dsthio->hio_length = srchio->hio_length;
 165         dsthio->hio_memsync = srchio->hio_memsync;
 166 }
 167
 168 static void
 169 init_environment(void)
 170 {
 171         struct hio *hio;
 172         unsigned int ii;
 173
 174         /*
 175          * Initialize lists, their locks and theirs condition variables.
 176          */
 177         TAILQ_INIT(&hio_free_list);
 178         mtx_init(&hio_free_list_lock);
 179         cv_init(&hio_free_list_cond);
 180         TAILQ_INIT(&hio_disk_list);
 181         mtx_init(&hio_disk_list_lock);
 182         cv_init(&hio_disk_list_cond);
 183         TAILQ_INIT(&hio_send_list);
 184         mtx_init(&hio_send_list_lock);
 185         cv_init(&hio_send_list_cond);
 186
 187         /*
 188          * Allocate requests pool and initialize requests.
 189          */
 190         for (ii = 0; ii < HAST_HIO_MAX; ii++) {
 191                 hio = malloc(sizeof(*hio));
 192                 if (hio == NULL) {
 193                         pjdlog_exitx(EX_TEMPFAIL,
 194                             "Unable to allocate memory (%zu bytes) for hio request.",
 195                             sizeof(*hio));
 196                 }
 197                 hio->hio_data = malloc(MAXPHYS);
 198                 if (hio->hio_data == NULL) {
 199                         pjdlog_exitx(EX_TEMPFAIL,
 200                             "Unable to allocate memory (%zu bytes) for gctl_data.",
 201                             (size_t)MAXPHYS);
 202                 }
 203                 hio_clear(hio);
 204                 TAILQ_INSERT_HEAD(&hio_free_list, hio, hio_next);
 205                 hio_free_list_size++;
 206         }
 207 }
 208
 209 static void
 210 init_local(struct hast_resource *res)
 211 {
 212
 213         if (metadata_read(res, true) == -1)
 214                 exit(EX_NOINPUT);
 215 }
 216
 217 static void
 218 init_remote(struct hast_resource *res, struct nv *nvin)
 219 {
 220         uint64_t resuid;
 221         struct nv *nvout;
 222         unsigned char *map;
 223         size_t mapsize;
 224
 225 #ifdef notyet
 226         /* Setup direction. */
 227         if (proto_send(res->hr_remoteout, NULL, 0) == -1)
 228                 pjdlog_errno(LOG_WARNING, "Unable to set connection direction");
 229 #endif
 230
 231         nvout = nv_alloc();
 232         nv_add_int64(nvout, (int64_t)res->hr_datasize, "datasize");
 233         nv_add_int32(nvout, (int32_t)res->hr_extentsize, "extentsize");
 234         resuid = nv_get_uint64(nvin, "resuid");
 235         res->hr_primary_localcnt = nv_get_uint64(nvin, "localcnt");
 236         res->hr_primary_remotecnt = nv_get_uint64(nvin, "remotecnt");
 237         nv_add_uint64(nvout, res->hr_secondary_localcnt, "localcnt");
 238         nv_add_uint64(nvout, res->hr_secondary_remotecnt, "remotecnt");
 239         mapsize = activemap_calc_ondisk_size(res->hr_local_mediasize -
 240             METADATA_SIZE, res->hr_extentsize, res->hr_local_sectorsize);
 241         map = malloc(mapsize);
 242         if (map == NULL) {
 243                 pjdlog_exitx(EX_TEMPFAIL,
 244                     "Unable to allocate memory (%zu bytes) for activemap.",
 245                     mapsize);
 246         }
 247         /*
 248          * When we work as primary and secondary is missing we will increase
 249          * localcnt in our metadata. When secondary is connected and synced
 250          * we make localcnt be equal to remotecnt, which means nodes are more
 251          * or less in sync.
 252          * Split-brain condition is when both nodes are not able to communicate
 253          * and are both configured as primary nodes. In turn, they can both
 254          * make incompatible changes to the data and we have to detect that.
 255          * Under split-brain condition we will increase our localcnt on first
 256          * write and remote node will increase its localcnt on first write.
 257          * When we connect we can see that primary's localcnt is greater than
 258          * our remotecnt (primary was modified while we weren't watching) and
 259          * our localcnt is greater than primary's remotecnt (we were modified
 260          * while primary wasn't watching).
 261          * There are many possible combinations which are all gathered below.
 262          * Don't pay too much attention to exact numbers, the more important
 263          * is to compare them. We compare secondary's local with primary's
 264          * remote and secondary's remote with primary's local.
 265          * Note that every case where primary's localcnt is smaller than
 266          * secondary's remotecnt and where secondary's localcnt is smaller than
 267          * primary's remotecnt should be impossible in practise. We will perform
 268          * full synchronization then. Those cases are marked with an asterisk.
 269          * Regular synchronization means that only extents marked as dirty are
 270          * synchronized (regular synchronization).
 271          *
 272          * SECONDARY METADATA PRIMARY METADATA
 273          * local=3 remote=3   local=2 remote=2*  ?! Full sync from secondary.
 274          * local=3 remote=3   local=2 remote=3*  ?! Full sync from primary.
 275          * local=3 remote=3   local=2 remote=4*  ?! Full sync from primary.
 276          * local=3 remote=3   local=3 remote=2   Primary is out-of-date,
 277          *                                       regular sync from secondary.
 278          * local=3 remote=3   local=3 remote=3   Regular sync just in case.
 279          * local=3 remote=3   local=3 remote=4*  ?! Full sync from primary.
 280          * local=3 remote=3   local=4 remote=2   Split-brain condition.
 281          * local=3 remote=3   local=4 remote=3   Secondary out-of-date,
 282          *                                       regular sync from primary.
 283          * local=3 remote=3   local=4 remote=4*  ?! Full sync from primary.
 284          */
 285         if (res->hr_resuid == 0) {
 286                 /*
 287                  * Provider is used for the first time. If primary node done no
 288                  * writes yet as well (we will find "virgin" argument) then
 289                  * there is no need to synchronize anything. If primary node
 290                  * done any writes already we have to synchronize everything.
 291                  */
 292                 PJDLOG_ASSERT(res->hr_secondary_localcnt == 0);
 293                 res->hr_resuid = resuid;
 294                 if (metadata_write(res) == -1)
 295                         exit(EX_NOINPUT);
 296                 if (nv_exists(nvin, "virgin")) {
 297                         free(map);
 298                         map = NULL;
 299                         mapsize = 0;
 300                 } else {
 301                         memset(map, 0xff, mapsize);
 302                 }
 303                 nv_add_int8(nvout, 1, "virgin");
 304                 nv_add_uint8(nvout, HAST_SYNCSRC_PRIMARY, "syncsrc");
 305         } else if (res->hr_resuid != resuid) {
 306                 char errmsg[256];
 307
 308                 free(map);
 309                 (void)snprintf(errmsg, sizeof(errmsg),
 310                     "Resource unique ID mismatch (primary=%ju, secondary=%ju).",
 311                     (uintmax_t)resuid, (uintmax_t)res->hr_resuid);
 312                 pjdlog_error("%s", errmsg);
 313                 nv_add_string(nvout, errmsg, "errmsg");
 314                 if (hast_proto_send(res, res->hr_remotein, nvout,
 315                     NULL, 0) == -1) {
 316                         pjdlog_exit(EX_TEMPFAIL,
 317                             "Unable to send response to %s",
 318                             res->hr_remoteaddr);
 319                 }
 320                 nv_free(nvout);
 321                 exit(EX_CONFIG);
 322         } else if (
 323             /* Is primary out-of-date? */
 324             (res->hr_secondary_localcnt > res->hr_primary_remotecnt &&
 325              res->hr_secondary_remotecnt == res->hr_primary_localcnt) ||
 326             /* Are the nodes more or less in sync? */
 327             (res->hr_secondary_localcnt == res->hr_primary_remotecnt &&
 328              res->hr_secondary_remotecnt == res->hr_primary_localcnt) ||
 329             /* Is secondary out-of-date? */
 330             (res->hr_secondary_localcnt == res->hr_primary_remotecnt &&
 331              res->hr_secondary_remotecnt < res->hr_primary_localcnt)) {
 332                 /*
 333                  * Nodes are more or less in sync or one of the nodes is
 334                  * out-of-date.
 335                  * It doesn't matter at this point which one, we just have to
 336                  * send out local bitmap to the remote node.
 337                  */
 338                 if (pread(res->hr_localfd, map, mapsize, METADATA_SIZE) !=
 339                     (ssize_t)mapsize) {
 340                         pjdlog_exit(LOG_ERR, "Unable to read activemap");
 341                 }
 342                 if (res->hr_secondary_localcnt > res->hr_primary_remotecnt &&
 343                      res->hr_secondary_remotecnt == res->hr_primary_localcnt) {
 344                         /* Primary is out-of-date, sync from secondary. */
 345                         nv_add_uint8(nvout, HAST_SYNCSRC_SECONDARY, "syncsrc");
 346                 } else {
 347                         /*
 348                          * Secondary is out-of-date or counts match.
 349                          * Sync from primary.
 350                          */
 351                         nv_add_uint8(nvout, HAST_SYNCSRC_PRIMARY, "syncsrc");
 352                 }
 353         } else if (res->hr_secondary_localcnt > res->hr_primary_remotecnt &&
 354              res->hr_primary_localcnt > res->hr_secondary_remotecnt) {
 355                 /*
 356                  * Not good, we have split-brain condition.
 357                  */
 358                 free(map);
 359                 pjdlog_error("Split-brain detected, exiting.");
 360                 nv_add_string(nvout, "Split-brain condition!", "errmsg");
 361                 if (hast_proto_send(res, res->hr_remotein, nvout,
 362                     NULL, 0) == -1) {
 363                         pjdlog_exit(EX_TEMPFAIL,
 364                             "Unable to send response to %s",
 365                             res->hr_remoteaddr);
 366                 }
 367                 nv_free(nvout);
 368                 /* Exit on split-brain. */
 369                 event_send(res, EVENT_SPLITBRAIN);
 370                 exit(EX_CONFIG);
 371         } else /* if (res->hr_secondary_localcnt < res->hr_primary_remotecnt ||
 372             res->hr_primary_localcnt < res->hr_secondary_remotecnt) */ {
 373                 /*
 374                  * This should never happen in practise, but we will perform
 375                  * full synchronization.
 376                  */
 377                 PJDLOG_ASSERT(res->hr_secondary_localcnt < res->hr_primary_remotecnt ||
 378                     res->hr_primary_localcnt < res->hr_secondary_remotecnt);
 379                 mapsize = activemap_calc_ondisk_size(res->hr_local_mediasize -
 380                     METADATA_SIZE, res->hr_extentsize,
 381                     res->hr_local_sectorsize);
 382                 memset(map, 0xff, mapsize);
 383                 if (res->hr_secondary_localcnt > res->hr_primary_remotecnt) {
 384                         /* In this one of five cases sync from secondary. */
 385                         nv_add_uint8(nvout, HAST_SYNCSRC_SECONDARY, "syncsrc");
 386                 } else {
 387                         /* For the rest four cases sync from primary. */
 388                         nv_add_uint8(nvout, HAST_SYNCSRC_PRIMARY, "syncsrc");
 389                 }
 390                 pjdlog_warning("This should never happen, asking for full synchronization (primary(local=%ju, remote=%ju), secondary(local=%ju, remote=%ju)).",
 391                     (uintmax_t)res->hr_primary_localcnt,
 392                     (uintmax_t)res->hr_primary_remotecnt,
 393                     (uintmax_t)res->hr_secondary_localcnt,
 394                     (uintmax_t)res->hr_secondary_remotecnt);
 395         }
 396         nv_add_uint32(nvout, (uint32_t)mapsize, "mapsize");
 397         if (hast_proto_send(res, res->hr_remotein, nvout, map, mapsize) == -1) {
 398                 pjdlog_exit(EX_TEMPFAIL, "Unable to send activemap to %s",
 399                     res->hr_remoteaddr);
 400         }
 401         if (map != NULL)
 402                 free(map);
 403         nv_free(nvout);
 404 #ifdef notyet
 405         /* Setup direction. */
 406         if (proto_recv(res->hr_remotein, NULL, 0) == -1)
 407                 pjdlog_errno(LOG_WARNING, "Unable to set connection direction");
 408 #endif
 409 }
 410
 411 void
 412 hastd_secondary(struct hast_resource *res, struct nv *nvin)
 413 {
 414         sigset_t mask;
 415         pthread_t td;
 416         pid_t pid;
 417         int error, mode, debuglevel;
 418
 419         /*
 420          * Create communication channel between parent and child.
 421          */
 422         if (proto_client(NULL, "socketpair://", &res->hr_ctrl) == -1) {
 423                 KEEP_ERRNO((void)pidfile_remove(pfh));
 424                 pjdlog_exit(EX_OSERR,
 425                     "Unable to create control sockets between parent and child");
 426         }
 427         /*
 428          * Create communication channel between child and parent.
 429          */
 430         if (proto_client(NULL, "socketpair://", &res->hr_event) == -1) {
 431                 KEEP_ERRNO((void)pidfile_remove(pfh));
 432                 pjdlog_exit(EX_OSERR,
 433                     "Unable to create event sockets between child and parent");
 434         }
 435
 436         pid = fork();
 437         if (pid == -1) {
 438                 KEEP_ERRNO((void)pidfile_remove(pfh));
 439                 pjdlog_exit(EX_OSERR, "Unable to fork");
 440         }
 441
 442         if (pid > 0) {
 443                 /* This is parent. */
 444                 proto_close(res->hr_remotein);
 445                 res->hr_remotein = NULL;
 446                 proto_close(res->hr_remoteout);
 447                 res->hr_remoteout = NULL;
 448                 /* Declare that we are receiver. */
 449                 proto_recv(res->hr_event, NULL, 0);
 450                 /* Declare that we are sender. */
 451                 proto_send(res->hr_ctrl, NULL, 0);
 452                 res->hr_workerpid = pid;
 453                 return;
 454         }
 455
 456         gres = res;
 457         res->output_status_aux = output_status_aux;
 458         mode = pjdlog_mode_get();
 459         debuglevel = pjdlog_debug_get();
 460
 461         /* Declare that we are sender. */
 462         proto_send(res->hr_event, NULL, 0);
 463         /* Declare that we are receiver. */
 464         proto_recv(res->hr_ctrl, NULL, 0);
 465         descriptors_cleanup(res);
 466
 467         descriptors_assert(res, mode);
 468
 469         pjdlog_init(mode);
 470         pjdlog_debug_set(debuglevel);
 471         pjdlog_prefix_set("[%s] (%s) ", res->hr_name, role2str(res->hr_role));
 472         setproctitle("%s (%s)", res->hr_name, role2str(res->hr_role));
 473
 474         PJDLOG_VERIFY(sigemptyset(&mask) == 0);
 475         PJDLOG_VERIFY(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 476
 477         /* Error in setting timeout is not critical, but why should it fail? */
 478         if (proto_timeout(res->hr_remotein, 2 * HAST_KEEPALIVE) == -1)
 479                 pjdlog_errno(LOG_WARNING, "Unable to set connection timeout");
 480         if (proto_timeout(res->hr_remoteout, res->hr_timeout) == -1)
 481                 pjdlog_errno(LOG_WARNING, "Unable to set connection timeout");
 482
 483         init_local(res);
 484         init_environment();
 485
 486         if (drop_privs(res) != 0)
 487                 exit(EX_CONFIG);
 488         pjdlog_info("Privileges successfully dropped.");
 489
 490         /*
 491          * Create the control thread before sending any event to the parent,
 492          * as we can deadlock when parent sends control request to worker,
 493          * but worker has no control thread started yet, so parent waits.
 494          * In the meantime worker sends an event to the parent, but parent
 495          * is unable to handle the event, because it waits for control
 496          * request response.
 497          */
 498         error = pthread_create(&td, NULL, ctrl_thread, res);
 499         PJDLOG_ASSERT(error == 0);
 500
 501         init_remote(res, nvin);
 502         event_send(res, EVENT_CONNECT);
 503
 504         error = pthread_create(&td, NULL, recv_thread, res);
 505         PJDLOG_ASSERT(error == 0);
 506         error = pthread_create(&td, NULL, disk_thread, res);
 507         PJDLOG_ASSERT(error == 0);
 508         (void)send_thread(res);
 509 }
 510
 511 static void
 512 reqlog(int loglevel, int debuglevel, int error, struct hio *hio,
 513     const char *fmt, ...)
 514 {
 515         char msg[1024];
 516         va_list ap;
 517         int len;
 518
 519         va_start(ap, fmt);
 520         len = vsnprintf(msg, sizeof(msg), fmt, ap);
 521         va_end(ap);
 522         if ((size_t)len < sizeof(msg)) {
 523                 switch (hio->hio_cmd) {
 524                 case HIO_READ:
 525                         (void)snprintf(msg + len, sizeof(msg) - len,
 526                             "READ(%ju, %ju).", (uintmax_t)hio->hio_offset,
 527                             (uintmax_t)hio->hio_length);
 528                         break;
 529                 case HIO_DELETE:
 530                         (void)snprintf(msg + len, sizeof(msg) - len,
 531                             "DELETE(%ju, %ju).", (uintmax_t)hio->hio_offset,
 532                             (uintmax_t)hio->hio_length);
 533                         break;
 534                 case HIO_FLUSH:
 535                         (void)snprintf(msg + len, sizeof(msg) - len, "FLUSH.");
 536                         break;
 537                 case HIO_WRITE:
 538                         (void)snprintf(msg + len, sizeof(msg) - len,
 539                             "WRITE(%ju, %ju).", (uintmax_t)hio->hio_offset,
 540                             (uintmax_t)hio->hio_length);
 541                         break;
 542                 case HIO_KEEPALIVE:
 543                         (void)snprintf(msg + len, sizeof(msg) - len, "KEEPALIVE.");
 544                         break;
 545                 default:
 546                         (void)snprintf(msg + len, sizeof(msg) - len,
 547                             "UNKNOWN(%u).", (unsigned int)hio->hio_cmd);
 548                         break;
 549                 }
 550         }
 551         pjdlog_common(loglevel, debuglevel, error, "%s", msg);
 552 }
 553
 554 static int
 555 requnpack(struct hast_resource *res, struct hio *hio, struct nv *nv)
 556 {
 557
 558         hio->hio_cmd = nv_get_uint8(nv, "cmd");
 559         if (hio->hio_cmd == 0) {
 560                 pjdlog_error("Header contains no 'cmd' field.");
 561                 hio->hio_error = EINVAL;
 562                 goto end;
 563         }
 564         if (hio->hio_cmd != HIO_KEEPALIVE) {
 565                 hio->hio_seq = nv_get_uint64(nv, "seq");
 566                 if (hio->hio_seq == 0) {
 567                         pjdlog_error("Header contains no 'seq' field.");
 568                         hio->hio_error = EINVAL;
 569                         goto end;
 570                 }
 571         }
 572         switch (hio->hio_cmd) {
 573         case HIO_FLUSH:
 574         case HIO_KEEPALIVE:
 575                 break;
 576         case HIO_WRITE:
 577                 hio->hio_memsync = nv_exists(nv, "memsync");
 578                 /* FALLTHROUGH */
 579         case HIO_READ:
 580         case HIO_DELETE:
 581                 hio->hio_offset = nv_get_uint64(nv, "offset");
 582                 if (nv_error(nv) != 0) {
 583                         pjdlog_error("Header is missing 'offset' field.");
 584                         hio->hio_error = EINVAL;
 585                         goto end;
 586                 }
 587                 hio->hio_length = nv_get_uint64(nv, "length");
 588                 if (nv_error(nv) != 0) {
 589                         pjdlog_error("Header is missing 'length' field.");
 590                         hio->hio_error = EINVAL;
 591                         goto end;
 592                 }
 593                 if (hio->hio_length == 0) {
 594                         pjdlog_error("Data length is zero.");
 595                         hio->hio_error = EINVAL;
 596                         goto end;
 597                 }
 598                 if (hio->hio_cmd != HIO_DELETE && hio->hio_length > MAXPHYS) {
 599                         pjdlog_error("Data length is too large (%ju > %ju).",
 600                             (uintmax_t)hio->hio_length, (uintmax_t)MAXPHYS);
 601                         hio->hio_error = EINVAL;
 602                         goto end;
 603                 }
 604                 if ((hio->hio_offset % res->hr_local_sectorsize) != 0) {
 605                         pjdlog_error("Offset %ju is not multiple of sector size.",
 606                             (uintmax_t)hio->hio_offset);
 607                         hio->hio_error = EINVAL;
 608                         goto end;
 609                 }
 610                 if ((hio->hio_length % res->hr_local_sectorsize) != 0) {
 611                         pjdlog_error("Length %ju is not multiple of sector size.",
 612                             (uintmax_t)hio->hio_length);
 613                         hio->hio_error = EINVAL;
 614                         goto end;
 615                 }
 616                 if (hio->hio_offset + hio->hio_length >
 617                     (uint64_t)res->hr_datasize) {
 618                         pjdlog_error("Data offset is too large (%ju > %ju).",
 619                             (uintmax_t)(hio->hio_offset + hio->hio_length),
 620                             (uintmax_t)res->hr_datasize);
 621                         hio->hio_error = EINVAL;
 622                         goto end;
 623                 }
 624                 break;
 625         default:
 626                 pjdlog_error("Header contains invalid 'cmd' (%hhu).",
 627                     hio->hio_cmd);
 628                 hio->hio_error = EINVAL;
 629                 goto end;
 630         }
 631         hio->hio_error = 0;
 632 end:
 633         return (hio->hio_error);
 634 }
 635
 636 static __dead2 void
 637 secondary_exit(int exitcode, const char *fmt, ...)
 638 {
 639         va_list ap;
 640
 641         PJDLOG_ASSERT(exitcode != EX_OK);
 642         va_start(ap, fmt);
 643         pjdlogv_errno(LOG_ERR, fmt, ap);
 644         va_end(ap);
 645         event_send(gres, EVENT_DISCONNECT);
 646         exit(exitcode);
 647 }
 648
 649 /*
 650  * Thread receives requests from the primary node.
 651  */
 652 static void *
 653 recv_thread(void *arg)
 654 {
 655         struct hast_resource *res = arg;
 656         struct hio *hio, *mshio;
 657         struct nv *nv;
 658
 659         for (;;) {
 660                 pjdlog_debug(2, "recv: Taking free request.");
 661                 QUEUE_TAKE(free, hio);
 662                 pjdlog_debug(2, "recv: (%p) Got request.", hio);
 663                 if (hast_proto_recv_hdr(res->hr_remotein, &nv) == -1) {
 664                         secondary_exit(EX_TEMPFAIL,
 665                             "Unable to receive request header");
 666                 }
 667                 if (requnpack(res, hio, nv) != 0) {
 668                         nv_free(nv);
 669                         pjdlog_debug(2,
 670                             "recv: (%p) Moving request to the send queue.",
 671                             hio);
 672                         QUEUE_INSERT(send, hio);
 673                         continue;
 674                 }
 675                 switch (hio->hio_cmd) {
 676                 case HIO_READ:
 677                         res->hr_stat_read++;
 678                         break;
 679                 case HIO_WRITE:
 680                         res->hr_stat_write++;
 681                         break;
 682                 case HIO_DELETE:
 683                         res->hr_stat_delete++;
 684                         break;
 685                 case HIO_FLUSH:
 686                         res->hr_stat_flush++;
 687                         break;
 688                 case HIO_KEEPALIVE:
 689                         break;
 690                 default:
 691                         PJDLOG_ABORT("Unexpected command (cmd=%hhu).",
 692                             hio->hio_cmd);
 693                 }
 694                 reqlog(LOG_DEBUG, 2, -1, hio,
 695                     "recv: (%p) Got request header: ", hio);
 696                 if (hio->hio_cmd == HIO_KEEPALIVE) {
 697                         nv_free(nv);
 698                         pjdlog_debug(2,
 699                             "recv: (%p) Moving request to the free queue.",
 700                             hio);
 701                         hio_clear(hio);
 702                         QUEUE_INSERT(free, hio);
 703                         continue;
 704                 } else if (hio->hio_cmd == HIO_WRITE) {
 705                         if (hast_proto_recv_data(res, res->hr_remotein, nv,
 706                             hio->hio_data, MAXPHYS) == -1) {
 707                                 secondary_exit(EX_TEMPFAIL,
 708                                     "Unable to receive request data");
 709                         }
 710                         if (hio->hio_memsync) {
 711                                 /*
 712                                  * For memsync requests we expect two replies.
 713                                  * Clone the hio so we can handle both of them.
 714                                  */
 715                                 pjdlog_debug(2, "recv: Taking free request.");
 716                                 QUEUE_TAKE(free, mshio);
 717                                 pjdlog_debug(2, "recv: (%p) Got request.",
 718                                     mshio);
 719                                 hio_copy(hio, mshio);
 720                                 mshio->hio_error = 0;
 721                                 /*
 722                                  * We want to keep 'memsync' tag only on the
 723                                  * request going onto send queue (mshio).
 724                                  */
 725                                 hio->hio_memsync = false;
 726                                 pjdlog_debug(2,
 727                                     "recv: (%p) Moving memsync request to the send queue.",
 728                                     mshio);
 729                                 QUEUE_INSERT(send, mshio);
 730                         }
 731                 }
 732                 nv_free(nv);
 733                 pjdlog_debug(2, "recv: (%p) Moving request to the disk queue.",
 734                     hio);
 735                 QUEUE_INSERT(disk, hio);
 736         }
 737         /* NOTREACHED */
 738         return (NULL);
 739 }
 740
 741 /*
 742  * Thread reads from or writes to local component and also handles DELETE and
 743  * FLUSH requests.
 744  */
 745 static void *
 746 disk_thread(void *arg)
 747 {
 748         struct hast_resource *res = arg;
 749         struct hio *hio;
 750         ssize_t ret;
 751         bool clear_activemap, logerror;
 752
 753         clear_activemap = true;
 754
 755         for (;;) {
 756                 pjdlog_debug(2, "disk: Taking request.");
 757                 QUEUE_TAKE(disk, hio);
 758                 while (clear_activemap) {
 759                         unsigned char *map;
 760                         size_t mapsize;
 761
 762                         /*
 763                          * When first request is received, it means that primary
 764                          * already received our activemap, merged it and stored
 765                          * locally. We can now safely clear our activemap.
 766                          */
 767                         mapsize =
 768                             activemap_calc_ondisk_size(res->hr_local_mediasize -
 769                             METADATA_SIZE, res->hr_extentsize,
 770                             res->hr_local_sectorsize);
 771                         map = calloc(1, mapsize);
 772                         if (map == NULL) {
 773                                 pjdlog_warning("Unable to allocate memory to clear local activemap.");
 774                                 break;
 775                         }
 776                         if (pwrite(res->hr_localfd, map, mapsize,
 777                             METADATA_SIZE) != (ssize_t)mapsize) {
 778                                 pjdlog_errno(LOG_WARNING,
 779                                     "Unable to store cleared activemap");
 780                                 free(map);
 781                                 res->hr_stat_activemap_write_error++;
 782                                 break;
 783                         }
 784                         free(map);
 785                         clear_activemap = false;
 786                         pjdlog_debug(1, "Local activemap cleared.");
 787                         break;
 788                 }
 789                 reqlog(LOG_DEBUG, 2, -1, hio, "disk: (%p) Got request: ", hio);
 790                 logerror = true;
 791                 /* Handle the actual request. */
 792                 switch (hio->hio_cmd) {
 793                 case HIO_READ:
 794                         ret = pread(res->hr_localfd, hio->hio_data,
 795                             hio->hio_length,
 796                             hio->hio_offset + res->hr_localoff);
 797                         if (ret == -1)
 798                                 hio->hio_error = errno;
 799                         else if (ret != (int64_t)hio->hio_length)
 800                                 hio->hio_error = EIO;
 801                         else
 802                                 hio->hio_error = 0;
 803                         break;
 804                 case HIO_WRITE:
 805                         ret = pwrite(res->hr_localfd, hio->hio_data,
 806                             hio->hio_length,
 807                             hio->hio_offset + res->hr_localoff);
 808                         if (ret == -1)
 809                                 hio->hio_error = errno;
 810                         else if (ret != (int64_t)hio->hio_length)
 811                                 hio->hio_error = EIO;
 812                         else
 813                                 hio->hio_error = 0;
 814                         break;
 815                 case HIO_DELETE:
 816                         ret = g_delete(res->hr_localfd,
 817                             hio->hio_offset + res->hr_localoff,
 818                             hio->hio_length);
 819                         if (ret == -1)
 820                                 hio->hio_error = errno;
 821                         else
 822                                 hio->hio_error = 0;
 823                         break;
 824                 case HIO_FLUSH:
 825                         if (!res->hr_localflush) {
 826                                 ret = -1;
 827                                 hio->hio_error = EOPNOTSUPP;
 828                                 logerror = false;
 829                                 break;
 830                         }
 831                         ret = g_flush(res->hr_localfd);
 832                         if (ret == -1) {
 833                                 if (errno == EOPNOTSUPP)
 834                                         res->hr_localflush = false;
 835                                 hio->hio_error = errno;
 836                         } else {
 837                                 hio->hio_error = 0;
 838                         }
 839                         break;
 840                 default:
 841                         PJDLOG_ABORT("Unexpected command (cmd=%hhu).",
 842                             hio->hio_cmd);
 843                 }
 844                 if (logerror && hio->hio_error != 0) {
 845                         reqlog(LOG_ERR, 0, hio->hio_error, hio,
 846                             "Request failed: ");
 847                 }
 848                 pjdlog_debug(2, "disk: (%p) Moving request to the send queue.",
 849                     hio);
 850                 QUEUE_INSERT(send, hio);
 851         }
 852         /* NOTREACHED */
 853         return (NULL);
 854 }
 855
 856 /*
 857  * Thread sends requests back to primary node.
 858  */
 859 static void *
 860 send_thread(void *arg)
 861 {
 862         struct hast_resource *res = arg;
 863         struct nv *nvout;
 864         struct hio *hio;
 865         void *data;
 866         size_t length;
 867
 868         for (;;) {
 869                 pjdlog_debug(2, "send: Taking request.");
 870                 QUEUE_TAKE(send, hio);
 871                 reqlog(LOG_DEBUG, 2, -1, hio, "send: (%p) Got request: ", hio);
 872                 nvout = nv_alloc();
 873                 /* Copy sequence number. */
 874                 nv_add_uint64(nvout, hio->hio_seq, "seq");
 875                 if (hio->hio_memsync) {
 876                         PJDLOG_ASSERT(hio->hio_cmd == HIO_WRITE);
 877                         nv_add_int8(nvout, 1, "received");
 878                 }
 879                 switch (hio->hio_cmd) {
 880                 case HIO_READ:
 881                         if (hio->hio_error == 0) {
 882                                 data = hio->hio_data;
 883                                 length = hio->hio_length;
 884                                 break;
 885                         }
 886                         /*
 887                          * We send no data in case of an error.
 888                          */
 889                         /* FALLTHROUGH */
 890                 case HIO_DELETE:
 891                 case HIO_FLUSH:
 892                 case HIO_WRITE:
 893                         data = NULL;
 894                         length = 0;
 895                         break;
 896                 default:
 897                         PJDLOG_ABORT("Unexpected command (cmd=%hhu).",
 898                             hio->hio_cmd);
 899                 }
 900                 if (hio->hio_error != 0) {
 901                         switch (hio->hio_cmd) {
 902                         case HIO_READ:
 903                                 res->hr_stat_read_error++;
 904                                 break;
 905                         case HIO_WRITE:
 906                                 res->hr_stat_write_error++;
 907                                 break;
 908                         case HIO_DELETE:
 909                                 res->hr_stat_delete_error++;
 910                                 break;
 911                         case HIO_FLUSH:
 912                                 res->hr_stat_flush_error++;
 913                                 break;
 914                         }
 915                         nv_add_int16(nvout, hio->hio_error, "error");
 916                 }
 917                 if (hast_proto_send(res, res->hr_remoteout, nvout, data,
 918                     length) == -1) {
 919                         secondary_exit(EX_TEMPFAIL, "Unable to send reply");
 920                 }
 921                 nv_free(nvout);
 922                 pjdlog_debug(2, "send: (%p) Moving request to the free queue.",
 923                     hio);
 924                 hio_clear(hio);
 925                 QUEUE_INSERT(free, hio);
 926         }
 927         /* NOTREACHED */
 928         return (NULL);
 929 }