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