sbin/hammer/cmd_pseudofs.c

   1 /*
   2  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/sbin/hammer/cmd_pseudofs.c,v 1.6 2008/07/12 02:48:46 dillon Exp $
  35  */
  36
  37 #include "hammer.h"
  38
  39 static void parse_pfsd_options(char **av, int ac, hammer_pseudofs_data_t pfsd);
  40 static void init_pfsd(hammer_pseudofs_data_t pfsd, int is_slave);
  41 static void dump_pfsd(hammer_pseudofs_data_t pfsd);
  42 static void pseudofs_usage(int code);
  43 static int getyn(void);
  44
  45 /*
  46  * Calculate the pfs_id given a path to a directory or a @@PFS or @@%llx:%d
  47  * softlink.
  48  */
  49 int
  50 getpfs(struct hammer_ioc_pseudofs_rw *pfs, const char *path)
  51 {
  52         hammer_tid_t dummy_tid;
  53         struct stat st;
  54         char *dirpath;
  55         char buf[64];
  56         int fd;
  57         int n;
  58
  59         bzero(pfs, sizeof(*pfs));
  60         pfs->ondisk = malloc(sizeof(*pfs->ondisk));
  61         bzero(pfs->ondisk, sizeof(*pfs->ondisk));
  62         pfs->bytes = sizeof(*pfs->ondisk);
  63
  64         /*
  65          * Calculate the directory containing the softlink
  66          */
  67         dirpath = strdup(path);
  68         if (strrchr(dirpath, '/'))
  69                 *strrchr(dirpath, '/') = 0;
  70         else
  71                 dirpath = strdup(".");
  72
  73         if (lstat(path, &st) == 0 && S_ISLNK(st.st_mode)) {
  74                 /*
  75                  * Avoid foot-shooting.  Don't let the user access a PFS
  76                  * softlink via a PFS.  PFS softlinks may only be accessed
  77                  * via the master filesystem.
  78                  */
  79                 fd = open(dirpath, O_RDONLY);
  80                 if (fd < 0)
  81                         goto done;
  82                 pfs->pfs_id = -1;
  83                 ioctl(fd, HAMMERIOC_GET_PSEUDOFS, pfs);
  84                 if (pfs->pfs_id != 0) {
  85                         fprintf(stderr,
  86                                 "You are attempting to access a PFS softlink "
  87                                 "from a PFS.  It may not represent the PFS\n"
  88                                 "on the main filesystem mount that you "
  89                                 "expect!  You may only access PFS softlinks\n"
  90                                 "via the main filesystem mount!\n");
  91                         exit(1);
  92                 }
  93                 close(fd);
  94
  95                 /*
  96                  * Extract the PFS from the link.  HAMMER will automatically
  97                  * convert @@PFS%05d links so if actually see one in that
  98                  * form the target PFS may not exist or may be corrupt.  But
  99                  * we can extract the PFS id anyway.
 100                  */
 101                 n = readlink(path, buf, sizeof(buf) - 1);
 102                 if (n < 0)
 103                         n = 0;
 104                 buf[n] = 0;
 105                 if (sscanf(buf, "@@PFS%d", &pfs->pfs_id) == 1) {
 106                         fd = open(dirpath, O_RDONLY);
 107                         goto done;
 108                 }
 109                 if (sscanf(buf, "@@%llx:%d", &dummy_tid, &pfs->pfs_id) == 2) {
 110                         fd = open(dirpath, O_RDONLY);
 111                         goto done;
 112                 }
 113         }
 114
 115         /*
 116          * Try to open the path and request the pfs_id that way.
 117          */
 118         fd = open(path, O_RDONLY);
 119         if (fd >= 0) {
 120                 pfs->pfs_id = -1;
 121                 ioctl(fd, HAMMERIOC_GET_PSEUDOFS, pfs);
 122                 if (pfs->pfs_id == -1) {
 123                         close(fd);
 124                         fd = -1;
 125                 }
 126         }
 127
 128         /*
 129          * Cleanup
 130          */
 131 done:
 132         if (fd < 0) {
 133                 fprintf(stderr, "Cannot access PFS %s: %s\n",
 134                         path, strerror(errno));
 135                 exit(1);
 136         }
 137         if (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, pfs) < 0) {
 138                 fprintf(stderr, "Cannot access PFS %s: %s\n",
 139                         path, strerror(errno));
 140                 exit(1);
 141         }
 142         free(dirpath);
 143         return(fd);
 144 }
 145
 146 void
 147 hammer_cmd_pseudofs_status(char **av, int ac)
 148 {
 149         struct hammer_ioc_pseudofs_rw pfs;
 150         int i;
 151         int fd;
 152
 153         for (i = 0; i < ac; ++i) {
 154                 printf("%s\t", av[i]);
 155                 fd = getpfs(&pfs, av[i]);
 156                 if (fd < 0 || ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pfs) < 0) {
 157                         printf("Not a HAMMER root\n");
 158                 } else {
 159                         printf("PFS #%d {\n", pfs.pfs_id);
 160                         dump_pfsd(pfs.ondisk);
 161                         printf("}\n");
 162                 }
 163                 if (fd >= 0)
 164                         close(fd);
 165                 if (pfs.ondisk)
 166                         free(pfs.ondisk);
 167         }
 168 }
 169
 170 void
 171 hammer_cmd_pseudofs_create(char **av, int ac, int is_slave)
 172 {
 173         struct hammer_ioc_pseudofs_rw pfs;
 174         struct hammer_pseudofs_data pfsd;
 175         struct stat st;
 176         const char *path;
 177         char *dirpath;
 178         char *linkpath;
 179         int pfs_id;
 180         int fd;
 181         int error;
 182
 183         if (ac == 0)
 184                 pseudofs_usage(1);
 185         path = av[0];
 186         if (lstat(path, &st) == 0) {
 187                 fprintf(stderr, "cannot create %s, file exists!\n", path);
 188                 exit(1);
 189         }
 190
 191         dirpath = strdup(path);
 192         if (strrchr(dirpath, '/') != NULL)
 193                 *strrchr(dirpath, '/') = 0;
 194         else
 195                 dirpath = strdup(".");
 196         fd = open(dirpath, O_RDONLY);
 197         if (fd < 0) {
 198                 fprintf(stderr, "Cannot open directory %s\n", dirpath);
 199                 exit(1);
 200         }
 201
 202         error = 0;
 203         for (pfs_id = 0; pfs_id < HAMMER_MAX_PFS; ++pfs_id) {
 204                 bzero(&pfs, sizeof(pfs));
 205                 bzero(&pfsd, sizeof(pfsd));
 206                 pfs.pfs_id = pfs_id;
 207                 pfs.ondisk = &pfsd;
 208                 pfs.bytes = sizeof(pfsd);
 209                 pfs.version = HAMMER_IOC_PSEUDOFS_VERSION;
 210                 if (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pfs) < 0) {
 211                         error = errno;
 212                         break;
 213                 }
 214         }
 215         if (pfs_id == HAMMER_MAX_PFS) {
 216                 fprintf(stderr, "Cannot create %s, all PFSs in use\n", path);
 217                 exit(1);
 218         }
 219         if (error != ENOENT) {
 220                 fprintf(stderr, "Cannot create %s, got %s during scan\n",
 221                         path, strerror(error));
 222                 exit(1);
 223         }
 224
 225         /*
 226          * Create the new PFS
 227          */
 228         printf("Creating PFS #%d\t", pfs_id);
 229         bzero(&pfsd, sizeof(pfsd));
 230         init_pfsd(&pfsd, is_slave);
 231         pfs.pfs_id = pfs_id;
 232         pfs.ondisk = &pfsd;
 233         pfs.bytes = sizeof(pfsd);
 234         pfs.version = HAMMER_IOC_PSEUDOFS_VERSION;
 235
 236         if (ioctl(fd, HAMMERIOC_SET_PSEUDOFS, &pfs) < 0) {
 237                 printf("failed: %s\n", strerror(errno));
 238         } else {
 239                 /* special symlink, must be exactly 10 characters */
 240                 asprintf(&linkpath, "@@PFS%05d", pfs_id);
 241                 if (symlink(linkpath, path) < 0) {
 242                         printf("failed: cannot create symlink: %s\n",
 243                                 strerror(errno));
 244                 } else {
 245                         printf("succeeded!\n");
 246                         hammer_cmd_pseudofs_update(av, ac);
 247                 }
 248         }
 249         close(fd);
 250 }
 251
 252 void
 253 hammer_cmd_pseudofs_destroy(char **av, int ac)
 254 {
 255         struct hammer_ioc_pseudofs_rw pfs;
 256         struct stat st;
 257         int fd;
 258         int i;
 259
 260         if (ac == 0)
 261                 pseudofs_usage(1);
 262         bzero(&pfs, sizeof(pfs));
 263         fd = getpfs(&pfs, av[0]);
 264
 265         if (pfs.pfs_id == 0) {
 266                 fprintf(stderr, "You cannot destroy PFS#0\n");
 267                 exit(1);
 268         }
 269         printf("You have requested that PFS#%d (%s) be destroyed\n",
 270                 pfs.pfs_id, pfs.ondisk->label);
 271         printf("This will irrevocably destroy all data on this PFS!!!!!\n");
 272         printf("Do you really want to do this? ");
 273         fflush(stdout);
 274         if (getyn() == 0) {
 275                 fprintf(stderr, "No action taken on PFS#%d\n", pfs.pfs_id);
 276                 exit(1);
 277         }
 278
 279         if ((pfs.ondisk->mirror_flags & HAMMER_PFSD_SLAVE) == 0) {
 280                 printf("This PFS is currently setup as a MASTER!\n");
 281                 printf("Are you absolutely sure you want to destroy it? ");
 282                 fflush(stdout);
 283                 if (getyn() == 0) {
 284                         fprintf(stderr, "No action taken on PFS#%d\n",
 285                                 pfs.pfs_id);
 286                         exit(1);
 287                 }
 288         }
 289
 290         printf("Destroying PFS #%d (%s) in ", pfs.pfs_id, pfs.ondisk->label);
 291         for (i = 5; i; --i) {
 292                 printf(" %d", i);
 293                 fflush(stdout);
 294                 sleep(1);
 295         }
 296         printf(".. starting destruction pass\n");
 297         fflush(stdout);
 298
 299         /*
 300          * Set the sync_beg_tid and sync_end_tid's to 1, once we start the
 301          * RMR the PFS is basically destroyed even if someone ^C's it.
 302          */
 303         pfs.ondisk->mirror_flags |= HAMMER_PFSD_SLAVE;
 304         pfs.ondisk->master_id = -1;
 305         pfs.ondisk->sync_beg_tid = 1;
 306         pfs.ondisk->sync_end_tid = 1;
 307
 308         if (ioctl(fd, HAMMERIOC_SET_PSEUDOFS, &pfs) < 0) {
 309                 fprintf(stderr, "Unable to update the PFS configuration: %s\n",
 310                         strerror(errno));
 311                 exit(1);
 312         }
 313
 314         /*
 315          * Ok, do it.  Remove the softlink on success.
 316          */
 317         if (ioctl(fd, HAMMERIOC_RMR_PSEUDOFS, &pfs) == 0) {
 318                 printf("pfs-destroy of PFS#%d succeeded!\n", pfs.pfs_id);
 319                 if (lstat(av[0], &st) == 0 && S_ISLNK(st.st_mode)) {
 320                         if (remove(av[0]) < 0) {
 321                                 fprintf(stderr, "Unable to remove softlink: %s "
 322                                         "(but the PFS has been destroyed)\n",
 323                                         av[0]);
 324                                 /* exit status 0 anyway */
 325                         }
 326                 }
 327         } else {
 328                 printf("pfs-destroy of PFS#%d failed: %s\n",
 329                         pfs.pfs_id, strerror(errno));
 330         }
 331 }
 332
 333 void
 334 hammer_cmd_pseudofs_upgrade(char **av, int ac)
 335 {
 336         struct hammer_ioc_pseudofs_rw pfs;
 337         int fd;
 338
 339         if (ac == 0)
 340                 pseudofs_usage(1);
 341         bzero(&pfs, sizeof(pfs));
 342         fd = getpfs(&pfs, av[0]);
 343
 344         if (pfs.pfs_id == 0) {
 345                 fprintf(stderr, "You cannot upgrade PFS#0"
 346                                 " (It should already be a master)\n");
 347                 exit(1);
 348         }
 349         if (pfs.ondisk->master_id == -1) {
 350                 fprintf(stderr, "You must configure a master id before "
 351                                 "upgrading a slave to a master.\n"
 352                                 "Use pfs-update ... master=<id> first.\n");
 353                 exit(1);
 354         }
 355
 356         if (ioctl(fd, HAMMERIOC_UPG_PSEUDOFS, &pfs) == 0) {
 357                 printf("pfs-upgrade of PFS#%d (%s) succeeded\n",
 358                         pfs.pfs_id, pfs.ondisk->label);
 359         } else {
 360                 fprintf(stderr, "pfs-upgrade of PFS#%d (%s) failed: %s\n",
 361                         pfs.pfs_id, pfs.ondisk->label, strerror(errno));
 362         }
 363 }
 364
 365 void
 366 hammer_cmd_pseudofs_downgrade(char **av, int ac)
 367 {
 368         struct hammer_ioc_pseudofs_rw pfs;
 369         int fd;
 370
 371         if (ac == 0)
 372                 pseudofs_usage(1);
 373         bzero(&pfs, sizeof(pfs));
 374         fd = getpfs(&pfs, av[0]);
 375
 376         if (pfs.pfs_id == 0) {
 377                 fprintf(stderr, "You cannot downgrade PFS#0\n");
 378                 exit(1);
 379         }
 380
 381         if (ioctl(fd, HAMMERIOC_DGD_PSEUDOFS, &pfs) == 0) {
 382                 printf("pfs-downgrade of PFS#%d (%s) succeeded\n",
 383                         pfs.pfs_id, pfs.ondisk->label);
 384         } else {
 385                 fprintf(stderr, "pfs-upgrade of PFS#%d (%s) failed: %s\n",
 386                         pfs.pfs_id, pfs.ondisk->label, strerror(errno));
 387         }
 388 }
 389
 390 void
 391 hammer_cmd_pseudofs_update(char **av, int ac)
 392 {
 393         struct hammer_ioc_pseudofs_rw pfs;
 394         int fd;
 395
 396         if (ac == 0)
 397                 pseudofs_usage(1);
 398         bzero(&pfs, sizeof(pfs));
 399         fd = getpfs(&pfs, av[0]);
 400
 401         printf("%s\n", av[0]);
 402         fflush(stdout);
 403
 404         if (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pfs) == 0) {
 405                 parse_pfsd_options(av + 1, ac - 1, pfs.ondisk);
 406                 if ((pfs.ondisk->mirror_flags & HAMMER_PFSD_SLAVE) &&
 407                     pfs.pfs_id == 0) {
 408                         printf("The real mount point cannot be made a PFS "
 409                                "slave, only PFS sub-directories can be made "
 410                                "slaves\n");
 411                         exit(1);
 412                 }
 413                 pfs.bytes = sizeof(*pfs.ondisk);
 414                 if (ioctl(fd, HAMMERIOC_SET_PSEUDOFS, &pfs) == 0) {
 415                         if (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pfs) == 0) {
 416                                 dump_pfsd(pfs.ondisk);
 417                         } else {
 418                                 printf("Unable to retrieve pfs configuration after successful update: %s\n", strerror(errno));
 419                                 exit(1);
 420                         }
 421                 } else {
 422                         printf("Unable to adjust pfs configuration: %s\n", strerror(errno));
 423                         exit(1);
 424                 }
 425         }
 426 }
 427
 428 static void
 429 init_pfsd(hammer_pseudofs_data_t pfsd, int is_slave)
 430 {
 431         uint32_t status;
 432
 433         pfsd->sync_beg_tid = 1;
 434         pfsd->sync_end_tid = 1;
 435         pfsd->sync_beg_ts = 0;
 436         pfsd->sync_end_ts = 0;
 437         uuid_create(&pfsd->shared_uuid, &status);
 438         uuid_create(&pfsd->unique_uuid, &status);
 439         if (is_slave) {
 440                 pfsd->master_id = -1;
 441                 pfsd->mirror_flags |= HAMMER_PFSD_SLAVE;
 442         } else {
 443                 pfsd->master_id = 0;
 444         }
 445 }
 446
 447 static
 448 void
 449 dump_pfsd(hammer_pseudofs_data_t pfsd)
 450 {
 451         u_int32_t status;
 452         char *str = NULL;
 453
 454         printf("    sync-beg-tid=0x%016llx\n", pfsd->sync_beg_tid);
 455         printf("    sync-end-tid=0x%016llx\n", pfsd->sync_end_tid);
 456         uuid_to_string(&pfsd->shared_uuid, &str, &status);
 457         printf("    shared-uuid=%s\n", str);
 458         uuid_to_string(&pfsd->unique_uuid, &str, &status);
 459         printf("    unique-uuid=%s\n", str);
 460         if (pfsd->mirror_flags & HAMMER_PFSD_SLAVE) {
 461                 printf("    slave\n");
 462         }
 463         if (pfsd->master_id < 0) {
 464                 if (pfsd->mirror_flags & HAMMER_PFSD_SLAVE) {
 465                         printf("    master=-1 "
 466                                "(no upgrade id assigned for slave)\n");
 467                 } else {
 468                         printf("    no-mirror "
 469                                "(mirror TID propagation disabled)\n");
 470                 }
 471         } else {
 472                 printf("    master=%d", pfsd->master_id);
 473                 if (pfsd->mirror_flags & HAMMER_PFSD_SLAVE)
 474                         printf(" (only if upgraded, currently a slave)");
 475                 printf("\n");
 476         }
 477         printf("    label=\"%s\"\n", pfsd->label);
 478 }
 479
 480 static void
 481 parse_pfsd_options(char **av, int ac, hammer_pseudofs_data_t pfsd)
 482 {
 483         char *cmd;
 484         char *ptr;
 485         int len;
 486         uint32_t status;
 487
 488         while (ac) {
 489                 cmd = *av;
 490                 if ((ptr = strchr(cmd, '=')) != NULL)
 491                         *ptr++ = 0;
 492
 493                 /*
 494                  * Basic assignment value test
 495                  */
 496                 if (strcmp(cmd, "no-mirror") == 0 ||
 497                     strcmp(cmd, "slave") == 0) {
 498                         if (ptr) {
 499                                 fprintf(stderr,
 500                                         "option %s should not have "
 501                                         "an assignment\n",
 502                                         cmd);
 503                                 exit(1);
 504                         }
 505                 } else {
 506                         if (ptr == NULL) {
 507                                 fprintf(stderr,
 508                                         "option %s requires an assignment\n",
 509                                         cmd);
 510                                 exit(1);
 511                         }
 512                 }
 513
 514                 status = uuid_s_ok;
 515                 if (strcmp(cmd, "sync-beg-tid") == 0) {
 516                         pfsd->sync_beg_tid = strtoull(ptr, NULL, 16);
 517                 } else if (strcmp(cmd, "sync-end-tid") == 0) {
 518                         pfsd->sync_end_tid = strtoull(ptr, NULL, 16);
 519                 } else if (strcmp(cmd, "shared-uuid") == 0) {
 520                         uuid_from_string(ptr, &pfsd->shared_uuid, &status);
 521                 } else if (strcmp(cmd, "unique-uuid") == 0) {
 522                         uuid_from_string(ptr, &pfsd->unique_uuid, &status);
 523                 } else if (strcmp(cmd, "master") == 0) {
 524                         if (pfsd->mirror_flags & HAMMER_PFSD_SLAVE) {
 525                                 printf("NOTE: This PFS is a slave, the master "
 526                                        "id you are setting only applies\n"
 527                                        "when you pfs-upgrade the PFS to "
 528                                        "a master!\n");
 529                         }
 530                         pfsd->master_id = strtol(ptr, NULL, 0);
 531                 } else if (strcmp(cmd, "slave") == 0) {
 532                         if ((pfsd->mirror_flags & HAMMER_PFSD_SLAVE) == 0) {
 533                                 fprintf(stderr,
 534                                         "slave mode cannot be set on a master "
 535                                         "PFS, use pfs-upgrade instead!\n");
 536                                 exit(1);
 537                         }
 538                         pfsd->mirror_flags |= HAMMER_PFSD_SLAVE;
 539                 } else if (strcmp(cmd, "no-mirror") == 0) {
 540                         if (pfsd->mirror_flags & HAMMER_PFSD_SLAVE) {
 541                                 fprintf(stderr,
 542                                         "no-mirror mode cannot be set on a "
 543                                         "slave PFS\n");
 544                                 exit(1);
 545                         }
 546                         pfsd->master_id = -1;
 547                         pfsd->mirror_flags &= ~HAMMER_PFSD_SLAVE;
 548                 } else if (strcmp(cmd, "label") == 0) {
 549                         len = strlen(ptr);
 550                         if (ptr[0] == '"' && ptr[len-1] == '"') {
 551                                 ptr[len-1] = 0;
 552                                 ++ptr;
 553                         } else if (ptr[0] == '"') {
 554                                 fprintf(stderr,
 555                                         "option %s: malformed string\n",
 556                                         cmd);
 557                                 exit(1);
 558                         }
 559                         snprintf(pfsd->label, sizeof(pfsd->label), "%s", ptr);
 560                 } else {
 561                         fprintf(stderr, "invalid option: %s\n", cmd);
 562                         exit(1);
 563                 }
 564                 if (status != uuid_s_ok) {
 565                         fprintf(stderr, "option %s: error parsing uuid %s\n",
 566                                 cmd, ptr);
 567                         exit(1);
 568                 }
 569                 --ac;
 570                 ++av;
 571         }
 572 }
 573
 574 static
 575 void
 576 pseudofs_usage(int code)
 577 {
 578         fprintf(stderr,
 579                 "hammer pfs-status <dirpath1>...<dirpathN>\n"
 580                 "hammer pfs-master <dirpath> [options]\n"
 581                 "hammer pfs-slave <dirpath> [options]\n"
 582                 "hammer pfs-update <dirpath> [options]\n"
 583                 "hammer pfs-upgrade <dirpath>\n"
 584                 "hammer pfs-downgrade <dirpath>\n"
 585                 "hammer pfs-destroy <dirpath>\n"
 586                 "\n"
 587                 "options:\n"
 588                 "    sync-beg-tid=0x16llx\n"
 589                 "    sync-end-tid=0x16llx\n"
 590                 "    shared-uuid=0x16llx\n"
 591                 "    unique-uuid=0x16llx\n"
 592                 "    master=0-15\n"
 593                 "    slave\n"
 594                 "    no-mirror\n"
 595                 "    label=\"string\"\n"
 596         );
 597         exit(code);
 598 }
 599
 600 static
 601 int
 602 getyn(void)
 603 {
 604         char buf[256];
 605         int len;
 606
 607         if (fgets(buf, sizeof(buf), stdin) == NULL)
 608                 return(0);
 609         len = strlen(buf);
 610         while (len && (buf[len-1] == '\n' || buf[len-1] == '\r'))
 611                 --len;
 612         buf[len] = 0;
 613         if (strcmp(buf, "y") == 0 ||
 614             strcmp(buf, "yes") == 0 ||
 615             strcmp(buf, "Y") == 0 ||
 616             strcmp(buf, "YES") == 0) {
 617                 return(1);
 618         }
 619         return(0);
 620 }
 621