sbin/hammer/cmd_snapshot.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_snapshot.c,v 1.7 2008/07/10 18:47:22 mneumann Exp $
  35  */
  36
  37 #include "hammer.h"
  38
  39 #define DEFAULT_SNAPSHOT_NAME "snap-%Y%m%d-%H%M"
  40
  41 static void snapshot_usage(int exit_code);
  42 static void snapshot_add(int fd, const char *fsym, const char *tsym,
  43                 const char *label, hammer_tid_t tid);
  44 static void snapshot_ls(const char *path);
  45 static void snapshot_del(int fsfd, hammer_tid_t tid);
  46 static char *dirpart(const char *path);
  47
  48 /*
  49  * hammer snap <path> [<note>]
  50  *
  51  * Path may be a directory, softlink, or non-existent (a softlink will be
  52  * created).
  53  */
  54 void
  55 hammer_cmd_snap(char **av, int ac, int tostdout, int fsbase)
  56 {
  57         struct hammer_ioc_synctid synctid;
  58         struct hammer_ioc_version version;
  59         char *dirpath;
  60         char *fsym = NULL;
  61         char *tsym = NULL;
  62         struct stat st;
  63         char note[64];
  64         int fsfd;
  65
  66         if (ac == 0 || ac > 2) {
  67                 snapshot_usage(1);
  68                 /* not reached */
  69         }
  70
  71         if (ac == 2)
  72                 snprintf(note, sizeof(note), "%s", av[1]);
  73         else
  74                 note[0] = 0;
  75
  76         /*
  77          * Figure out the softlink path and directory path
  78          */
  79         if (stat(av[0], &st) < 0) {
  80                 dirpath = dirpart(av[0]);
  81                 tsym = strdup(av[0]);
  82         } else if (S_ISDIR(st.st_mode)) {
  83                 time_t t = time(NULL);
  84                 struct tm *tp;
  85                 char extbuf[64];
  86
  87                 tp = localtime(&t);
  88                 strftime(extbuf, sizeof(extbuf), DEFAULT_SNAPSHOT_NAME, tp);
  89
  90                 dirpath = strdup(av[0]);
  91                 asprintf(&tsym, "%s/%s", dirpath, extbuf);
  92         } else {
  93                 err(2, "hammer snap: File %s exists and is not a directory",
  94                     av[0]);
  95         }
  96
  97         /*
  98          * Get a handle on some directory in the filesystem for the
  99          * ioctl (so it is stored in the correct PFS).
 100          */
 101         fsfd = open(dirpath, O_RDONLY);
 102         if (fsfd < 0)
 103                 err(2, "hammer snap: Cannot open directory %s", dirpath);
 104
 105         /*
 106          * Must be at least version 3 to use this command.
 107          */
 108         bzero(&version, sizeof(version));
 109
 110         if (ioctl(fsfd, HAMMERIOC_GET_VERSION, &version) < 0)
 111                 err(2, "Unable to create snapshot");
 112         else if (version.cur_version < 3)
 113                 errx(2, "Unable to create snapshot: This directive requires "
 114                         "you to upgrade\n"
 115                         "the filesystem to version 3.  "
 116                         "Use 'hammer snapshot' for legacy operation.");
 117         HammerVersion = version.cur_version;
 118
 119         /*
 120          * Synctid to get a transaction id for the snapshot.
 121          */
 122         bzero(&synctid, sizeof(synctid));
 123         synctid.op = HAMMER_SYNCTID_SYNC2;
 124         if (ioctl(fsfd, HAMMERIOC_SYNCTID, &synctid) < 0)
 125                 err(2, "hammer snap: Synctid %s failed",
 126                     dirpath);
 127         if (tostdout) {
 128                 if (strcmp(dirpath, ".") == 0 || strcmp(dirpath, "..") == 0)
 129                         printf("%s/@@0x%016jx\n",
 130                                 dirpath, (uintmax_t)synctid.tid);
 131                 else
 132                         printf("%s@@0x%016jx\n",
 133                                 dirpath, (uintmax_t)synctid.tid);
 134                 fsym = NULL;
 135                 tsym = NULL;
 136         }
 137
 138         /*
 139          * Contents of the symlink being created.
 140          */
 141         if (fsbase) {
 142                 struct statfs buf;
 143
 144                 if (statfs(dirpath, &buf) < 0)
 145                         err(2, "hammer snap: Cannot determine mount for %s",
 146                             dirpath);
 147                 asprintf(&fsym, "%s/@@0x%016jx",
 148                          buf.f_mntonname, (uintmax_t)synctid.tid);
 149         } else if (strcmp(dirpath, ".") == 0 || strcmp(dirpath, "..") == 0) {
 150                 asprintf(&fsym, "%s/@@0x%016jx",
 151                          dirpath, (uintmax_t)synctid.tid);
 152         } else {
 153                 asprintf(&fsym, "%s@@0x%016jx",
 154                          dirpath, (uintmax_t)synctid.tid);
 155         }
 156
 157         /*
 158          * Create the snapshot.
 159          */
 160         snapshot_add(fsfd, fsym, tsym, note, synctid.tid);
 161         free(dirpath);
 162         free(fsym);
 163         free(tsym);
 164 }
 165
 166 /*
 167  * hammer snapls [<path> ...]
 168  *
 169  * If no arguments are specified snapshots for the PFS containing the
 170  * current directory are listed.
 171  */
 172 void
 173 hammer_cmd_snapls(char **av, int ac)
 174 {
 175         int i;
 176
 177         for (i = 0; i < ac; ++i)
 178                 snapshot_ls(av[i]);
 179         if (ac == 0)
 180                 snapshot_ls(".");
 181 }
 182
 183 /*
 184  * hammer snaprm <path> ...
 185  * hammer snaprm <transid> ...
 186  * hammer snaprm <filesystem> <transid> ...
 187  */
 188 void
 189 hammer_cmd_snaprm(char **av, int ac)
 190 {
 191         struct stat st;
 192         char linkbuf[1024];
 193         intmax_t tid;
 194         int fsfd = -1;
 195         int i;
 196         int delete;
 197         enum snaprm_mode { none_m, path_m, tid_m } mode = none_m;
 198         char *dirpath;
 199         char *ptr, *ptr2;
 200
 201         if (ac == 0) {
 202                 snapshot_usage(1);
 203                 /* not reached */
 204         }
 205
 206         for (i = 0; i < ac; ++i) {
 207                 if (lstat(av[i], &st) < 0) {
 208                         tid = strtoull(av[i], &ptr, 16);
 209                         if (*ptr)
 210                                 err(2, "hammer snaprm: not a file or tid: %s",
 211                                     av[i]);
 212                         if (mode == path_m) {
 213                                 snapshot_usage(1);
 214                                 /* not reached */
 215                         }
 216                         mode = tid_m;
 217                         if (fsfd < 0)
 218                                 fsfd = open(".", O_RDONLY);
 219                         snapshot_del(fsfd, tid);
 220                 } else if (S_ISDIR(st.st_mode)) {
 221                         if (i != 0 || ac < 2) {
 222                                 snapshot_usage(1);
 223                                 /* not reached */
 224                         }
 225                         if (fsfd >= 0)
 226                                 close(fsfd);
 227                         fsfd = open(av[i], O_RDONLY);
 228                         if (fsfd < 0)
 229                                 err(2, "hammer snaprm: cannot open dir %s",
 230                                     av[i]);
 231                         mode = tid_m;
 232                 } else if (S_ISLNK(st.st_mode)) {
 233                         dirpath = dirpart(av[i]);
 234                         bzero(linkbuf, sizeof(linkbuf));
 235                         if (readlink(av[i], linkbuf, sizeof(linkbuf) - 1) < 0)
 236                                 err(2, "hammer snaprm: cannot read softlink: "
 237                                        "%s", av[i]);
 238                         if (linkbuf[0] == '/') {
 239                                 free(dirpath);
 240                                 dirpath = dirpart(linkbuf);
 241                         } else {
 242                                 asprintf(&ptr, "%s/%s", dirpath, linkbuf);
 243                                 free(dirpath);
 244                                 dirpath = dirpart(ptr);
 245                                 free(ptr);
 246                         }
 247
 248                         if (fsfd >= 0)
 249                                 close(fsfd);
 250                         fsfd = open(dirpath, O_RDONLY);
 251                         if (fsfd < 0)
 252                                 err(2, "hammer snaprm: cannot open dir %s",
 253                                     dirpath);
 254
 255                         delete = 1;
 256                         if (i == 0 && ac > 1) {
 257                                 mode = path_m;
 258                                 if (lstat(av[1], &st) < 0) {
 259                                         tid = strtoull(av[1], &ptr, 16);
 260                                         if (*ptr == '\0') {
 261                                                 delete = 0;
 262                                                 mode = tid_m;
 263                                         }
 264                                 }
 265                         } else {
 266                                 if (mode == tid_m) {
 267                                         snapshot_usage(1);
 268                                         /* not reached */
 269                                 }
 270                                 mode = path_m;
 271                         }
 272                         if (delete && (ptr = strrchr(linkbuf, '@')) &&
 273                             ptr > linkbuf && ptr[-1] == '@' && ptr[1]) {
 274                                 tid = strtoull(ptr + 1, &ptr2, 16);
 275                                 if (*ptr2 == '\0') {
 276                                         snapshot_del(fsfd, tid);
 277                                         remove(av[i]);
 278                                 }
 279                         }
 280                         free(dirpath);
 281                 } else {
 282                         err(2, "hammer snaprm: not directory or snapshot "
 283                                "softlink: %s", av[i]);
 284                 }
 285         }
 286         if (fsfd >= 0)
 287                 close(fsfd);
 288 }
 289
 290 /*
 291  * snapshot <softlink-dir>
 292  * snapshot <filesystem> <softlink-dir> [<note>]
 293  */
 294 void
 295 hammer_cmd_snapshot(char **av, int ac)
 296 {
 297         const char *filesystem;
 298         const char *softlink_dir;
 299         char *softlink_fmt;
 300         struct statfs buf;
 301         struct stat st;
 302         struct hammer_ioc_synctid synctid;
 303         char *from;
 304         char *to;
 305         char *note = NULL;
 306
 307         if (ac == 1) {
 308                 filesystem = NULL;
 309                 softlink_dir = av[0];
 310         } else if (ac == 2) {
 311                 filesystem = av[0];
 312                 softlink_dir = av[1];
 313         } else if (ac == 3) {
 314                 filesystem = av[0];
 315                 softlink_dir = av[1];
 316                 note = av[2];
 317         } else {
 318                 snapshot_usage(1);
 319                 /* not reached */
 320         }
 321
 322         if (stat(softlink_dir, &st) == 0) {
 323                 if (!S_ISDIR(st.st_mode))
 324                         err(2, "File %s already exists", softlink_dir);
 325
 326                 if (filesystem == NULL) {
 327                         if (statfs(softlink_dir, &buf) != 0)
 328                                 err(2, "Unable to determine filesystem of %s",
 329                                     softlink_dir);
 330                         filesystem = buf.f_mntonname;
 331                 }
 332
 333                 softlink_fmt = malloc(strlen(softlink_dir) + 1 + 1 +
 334                                       sizeof(DEFAULT_SNAPSHOT_NAME));
 335                 if (softlink_fmt == NULL)
 336                         err(2, "Failed to allocate string");
 337
 338                 strcpy(softlink_fmt, softlink_dir);
 339                 if (softlink_fmt[strlen(softlink_fmt)-1] != '/')
 340                         strcat(softlink_fmt, "/");
 341                 strcat(softlink_fmt, DEFAULT_SNAPSHOT_NAME);
 342         } else {
 343                 softlink_fmt = strdup(softlink_dir);
 344
 345                 if (filesystem == NULL) {
 346                         /*
 347                          * strip-off last '/path' segment to get the softlink
 348                          * directory, which we need to determine the filesystem
 349                          * we are on.
 350                          */
 351                         char *pos = strrchr(softlink_fmt, '/');
 352                         if (pos != NULL)
 353                                 *pos = '\0';
 354
 355                         if (stat(softlink_fmt, &st) != 0 ||
 356                             !S_ISDIR(st.st_mode))
 357                                 err(2, "Unable to determine softlink dir %s",
 358                                     softlink_fmt);
 359                         if (statfs(softlink_fmt, &buf) != 0)
 360                                 err(2, "Unable to determine filesystem of %s",
 361                                     softlink_fmt);
 362                         filesystem = buf.f_mntonname;
 363
 364                         /* restore '/' */
 365                         if (pos != NULL)
 366                                 *pos = '/';
 367                 }
 368         }
 369
 370         /*
 371          * Synctid
 372          */
 373         bzero(&synctid, sizeof(synctid));
 374         synctid.op = HAMMER_SYNCTID_SYNC2;
 375
 376         int fd = open(filesystem, O_RDONLY);
 377         if (fd < 0)
 378                 err(2, "Unable to open %s", filesystem);
 379         if (ioctl(fd, HAMMERIOC_SYNCTID, &synctid) < 0)
 380                 err(2, "Synctid %s failed", filesystem);
 381
 382         asprintf(&from, "%s/@@0x%016jx", filesystem, (uintmax_t)synctid.tid);
 383         if (from == NULL)
 384                 err(2, "Couldn't generate string");
 385
 386         int sz = strlen(softlink_fmt) + 50;
 387         to = malloc(sz);
 388         if (to == NULL)
 389                 err(2, "Failed to allocate string");
 390
 391         time_t t = time(NULL);
 392         if (strftime(to, sz, softlink_fmt, localtime(&t)) == 0)
 393                 err(2, "String buffer too small");
 394
 395         asprintf(&from, "%s/@@0x%016jx", filesystem, (uintmax_t)synctid.tid);
 396
 397         snapshot_add(fd, from, to, note, synctid.tid);
 398
 399         close(fd);
 400         printf("%s\n", to);
 401
 402         free(softlink_fmt);
 403         free(from);
 404         free(to);
 405 }
 406
 407 static
 408 void
 409 snapshot_add(int fd, const char *fsym, const char *tsym, const char *label,
 410              hammer_tid_t tid)
 411 {
 412         struct hammer_ioc_version version;
 413         struct hammer_ioc_snapshot snapshot;
 414
 415         bzero(&version, sizeof(version));
 416         bzero(&snapshot, sizeof(snapshot));
 417
 418         /*
 419          * For HAMMER filesystem v3+ the snapshot is recorded in meta-data.
 420          */
 421         if (ioctl(fd, HAMMERIOC_GET_VERSION, &version) == 0 &&
 422             version.cur_version >= 3) {
 423                 HammerVersion = version.cur_version;
 424                 snapshot.index = 0;
 425                 snapshot.count = 1;
 426                 snapshot.snaps[0].tid = tid;
 427                 snapshot.snaps[0].ts = time(NULL) * 1000000ULL;
 428                 if (label)
 429                         snprintf(snapshot.snaps[0].label,
 430                                  sizeof(snapshot.snaps[0].label),
 431                                  "%s",
 432                                  label);
 433                 if (ioctl(fd, HAMMERIOC_ADD_SNAPSHOT, &snapshot) < 0)
 434                         err(2, "Unable to create snapshot");
 435                 else if (snapshot.head.error && snapshot.head.error != EEXIST)
 436                         errx(2, "Unable to create snapshot: %s",
 437                                 strerror(snapshot.head.error));
 438         }
 439
 440         /*
 441          * Create a symlink for the snapshot.  If a file exists with the same
 442          * name the new symlink will replace it.
 443          */
 444         if (fsym && tsym) {
 445                 remove(tsym);
 446                 if (symlink(fsym, tsym) < 0)
 447                         err(2, "Unable to create symlink %s", tsym);
 448         }
 449 }
 450
 451 static
 452 void
 453 snapshot_ls(const char *path)
 454 {
 455         struct hammer_ioc_info info;
 456         struct hammer_ioc_snapshot snapshot;
 457         struct hammer_ioc_pseudofs_rw pfs;
 458         struct hammer_pseudofs_data pfs_od;
 459         hammer_snapshot_data_t snap;
 460         struct tm *tp;
 461         time_t t;
 462         uint32_t i;
 463         int fd;
 464         char snapts[64];
 465
 466         fd = open(path, O_RDONLY);
 467         if (fd < 0)
 468                 err(2, "hammer snapls: cannot open %s", path);
 469
 470         clrpfs(&pfs, &pfs_od, -1);
 471         if (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pfs) < 0)
 472                 err(2, "hammer snapls: cannot retrieve PFS info on %s", path);
 473
 474         bzero(&info, sizeof(info));
 475         if ((ioctl(fd, HAMMERIOC_GET_INFO, &info)) < 0)
 476                 err(2, "hammer snapls: cannot retrieve HAMMER info");
 477
 478         printf("Snapshots on %s\tPFS#%d\n", path, pfs.pfs_id);
 479         printf("Transaction ID\t\tTimestamp\t\tNote\n");
 480
 481         bzero(&snapshot, sizeof(snapshot));
 482         do {
 483                 if (ioctl(fd, HAMMERIOC_GET_SNAPSHOT, &snapshot) < 0)
 484                         err(2, "hammer snapls: %s: not HAMMER fs or "
 485                                 "version < 3", path);
 486                 for (i = 0; i < snapshot.count; ++i) {
 487                         snap = &snapshot.snaps[i];
 488
 489                         t = snap->ts / 1000000ULL;
 490                         tp = localtime(&t);
 491                         strftime(snapts, sizeof(snapts),
 492                                  "%Y-%m-%d %H:%M:%S %Z", tp);
 493                         printf("0x%016jx\t%s\t%s\n",
 494                                 (uintmax_t)snap->tid, snapts,
 495                                 strlen(snap->label) ? snap->label : "-");
 496                 }
 497         } while (snapshot.head.error == 0 && snapshot.count);
 498 }
 499
 500 static
 501 void
 502 snapshot_del(int fsfd, hammer_tid_t tid)
 503 {
 504         struct hammer_ioc_snapshot snapshot;
 505         struct hammer_ioc_version version;
 506
 507         bzero(&version, sizeof(version));
 508
 509         if (ioctl(fsfd, HAMMERIOC_GET_VERSION, &version) < 0)
 510                 err(2, "hammer snaprm 0x%016jx", (uintmax_t)tid);
 511         HammerVersion = version.cur_version;
 512         if (version.cur_version < 3)
 513                 errx(2, "hammer snaprm 0x%016jx: You must upgrade to version "
 514                         " 3 to use this directive", (uintmax_t)tid);
 515
 516         bzero(&snapshot, sizeof(snapshot));
 517         snapshot.count = 1;
 518         snapshot.snaps[0].tid = tid;
 519
 520         /*
 521          * Do not abort if we are unable to remove the meta-data.
 522          */
 523         if (ioctl(fsfd, HAMMERIOC_DEL_SNAPSHOT, &snapshot) < 0)
 524                 err(2, "hammer snaprm 0x%016jx",
 525                       (uintmax_t)tid);
 526         else if (snapshot.head.error == ENOENT)
 527                 fprintf(stderr, "Warning: hammer snaprm 0x%016jx: "
 528                                 "meta-data not found\n",
 529                         (uintmax_t)tid);
 530         else if (snapshot.head.error)
 531                 fprintf(stderr, "Warning: hammer snaprm 0x%016jx: %s\n",
 532                         (uintmax_t)tid, strerror(snapshot.head.error));
 533 }
 534
 535 static
 536 void
 537 snapshot_usage(int exit_code)
 538 {
 539         fprintf(stderr,
 540     "hammer snap <path> [<note>]\t\tcreate snapshot & link, points to\n"
 541                                 "\t\t\t\t\tbase of PFS mount\n"
 542     "hammer snaplo <path> [<note>]\t\tcreate snapshot & link, points to\n"
 543                                 "\t\t\t\t\ttarget dir\n"
 544     "hammer snapq <dir> [<note>]\t\tcreate snapshot, output path to stdout\n"
 545     "hammer snaprm <path> ...\t\tdelete snapshots; filesystem is CWD\n"
 546     "hammer snaprm <transid> ...\t\tdelete snapshots\n"
 547     "hammer snaprm <filesystem> <transid> ...\tdelete snapshots\n"
 548     "hammer snapls [<path> ...]\t\tlist available snapshots\n"
 549     "\n"
 550     "NOTE: Snapshots are created in filesystem meta-data, any directory\n"
 551     "      in a HAMMER filesystem or PFS may be specified.  If the path\n"
 552     "      specified does not exist this function will also create a\n"
 553     "      softlink.\n"
 554     "\n"
 555     "      When deleting snapshots transaction ids may be directly specified\n"
 556     "      or file paths to snapshot softlinks may be specified.  If a\n"
 557     "      softlink is specified the softlink will also be deleted.\n"
 558     "\n"
 559     "NOTE: The old 'hammer snapshot [<filesystem>] <snapshot-dir>' form\n"
 560     "      is still accepted but is a deprecated form.  This form will\n"
 561     "      work for older hammer versions.  The new forms only work for\n"
 562     "      HAMMER version 3 or later filesystems.  HAMMER can be upgraded\n"
 563     "      to version 3 in-place.\n"
 564         );
 565         exit(exit_code);
 566 }
 567
 568 static
 569 char *
 570 dirpart(const char *path)
 571 {
 572         const char *ptr;
 573         char *res;
 574
 575         ptr = strrchr(path, '/');
 576         if (ptr) {
 577                 while (ptr > path && ptr[-1] == '/')
 578                         --ptr;
 579                 if (ptr == path)
 580                         ptr = NULL;
 581         }
 582         if (ptr == NULL) {
 583                 path = ".";
 584                 ptr = path + 1;
 585         }
 586         res = malloc(ptr - path + 1);
 587         bcopy(path, res, ptr - path);
 588         res[ptr - path] = 0;
 589         return(res);
 590 }