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