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 #include <sys/param.h>
  39 #include <sys/mount.h>
  40 #include <sys/types.h>
  41 #include <sys/stat.h>
  42 #include <unistd.h>
  43 #include <string.h>
  44 #include <time.h>
  45
  46 #define DEFAULT_SNAPSHOT_NAME "snap-%Y%m%d-%H%M"
  47
  48 static void snapshot_usage(int exit_code);
  49 static void snapshot_add(int fd, const char *fsym, const char *tsym,
  50                 const char *label, hammer_tid_t tid);
  51 static void snapshot_ls(const char *path);
  52 static void snapshot_del(int fsfd, hammer_tid_t tid);
  53 static char *dirpart(const char *path);
  54
  55 /*
  56  * hammer snap <path> [<note>]
  57  *
  58  * Path may be a directory, softlink, or non-existent (a softlink will be
  59  * created).
  60  */
  61 void
  62 hammer_cmd_snap(char **av, int ac, int tostdout, int fsbase)
  63 {
  64         struct hammer_ioc_synctid synctid;
  65         struct hammer_ioc_version version;
  66         char *dirpath;
  67         char *fsym;
  68         char *tsym;
  69         struct stat st;
  70         char note[64];
  71         int fsfd;
  72
  73         if (ac == 0 || ac > 2) {
  74                 snapshot_usage(1);
  75                 /* not reached */
  76                 exit(1);
  77         }
  78
  79         if (ac == 2)
  80                 snprintf(note, sizeof(note), "%s", av[1]);
  81         else
  82                 note[0] = 0;
  83
  84         /*
  85          * Figure out the softlink path and directory path
  86          */
  87         if (stat(av[0], &st) < 0) {
  88                 dirpath = dirpart(av[0]);
  89                 tsym = av[0];
  90         } else if (S_ISLNK(st.st_mode)) {
  91                 dirpath = dirpart(av[0]);
  92                 tsym = av[0];
  93         } else if (S_ISDIR(st.st_mode)) {
  94                 time_t t = time(NULL);
  95                 struct tm *tp;
  96                 char extbuf[64];
  97
  98                 tp = localtime(&t);
  99                 strftime(extbuf, sizeof(extbuf), DEFAULT_SNAPSHOT_NAME, tp);
 100
 101                 dirpath = strdup(av[0]);
 102                 asprintf(&tsym, "%s/%s", dirpath, extbuf);
 103         } else {
 104                 err(2, "hammer snap: File %s exists and is not a softlink\n",
 105                     av[0]);
 106                 /* not reached */
 107         }
 108
 109         /*
 110          * Get a handle on some directory in the filesystem for the
 111          * ioctl (so it is stored in the correct PFS).
 112          */
 113         fsfd = open(dirpath, O_RDONLY);
 114         if (fsfd < 0) {
 115                 err(2, "hammer snap: Cannot open directory %s\n", dirpath);
 116                 /* not reached */
 117         }
 118
 119         /*
 120          * Must be at least version 3 to use this command.
 121          */
 122         bzero(&version, sizeof(version));
 123
 124         if (ioctl(fsfd, HAMMERIOC_GET_VERSION, &version) < 0) {
 125                 err(2, "Unable to create snapshot");
 126                 /* not reached */
 127         } else if (version.cur_version < 3) {
 128                 errx(2, "Unable to create snapshot: This directive requires "
 129                         "you to upgrade\n"
 130                         "the filesystem to version 3.  "
 131                         "Use 'hammer snapshot' for legacy operation.");
 132                 /* not reached */
 133         }
 134
 135         /*
 136          * Synctid to get a transaction id for the snapshot.
 137          */
 138         bzero(&synctid, sizeof(synctid));
 139         synctid.op = HAMMER_SYNCTID_SYNC2;
 140         if (ioctl(fsfd, HAMMERIOC_SYNCTID, &synctid) < 0) {
 141                 err(2, "hammer snap: Synctid %s failed",
 142                     dirpath);
 143         }
 144         if (tostdout) {
 145                 if (strcmp(dirpath, ".") == 0 || strcmp(dirpath, "..") == 0) {
 146                         printf("%s/@@0x%016jx\n",
 147                                 dirpath, (uintmax_t)synctid.tid);
 148                 } else {
 149                         printf("%s@@0x%016jx\n",
 150                                 dirpath, (uintmax_t)synctid.tid);
 151                 }
 152                 fsym = NULL;
 153                 tsym = NULL;
 154         }
 155
 156         /*
 157          * Contents of the symlink being created.
 158          */
 159         if (fsbase) {
 160                 struct statfs buf;
 161
 162                 if (statfs(dirpath, &buf) < 0) {
 163                         err(2, "hammer snap: Cannot determine mount for %s",
 164                             dirpath);
 165                 }
 166                 asprintf(&fsym, "%s/@@0x%016jx",
 167                          buf.f_mntonname, (uintmax_t)synctid.tid);
 168         } else if (strcmp(dirpath, ".") == 0 || strcmp(dirpath, "..") == 0) {
 169                 asprintf(&fsym, "%s/@@0x%016jx",
 170                          dirpath, (uintmax_t)synctid.tid);
 171         } else {
 172                 asprintf(&fsym, "%s@@0x%016jx",
 173                          dirpath, (uintmax_t)synctid.tid);
 174         }
 175
 176         /*
 177          * Create the snapshot.
 178          */
 179         snapshot_add(fsfd, fsym, tsym, note, synctid.tid);
 180         free(dirpath);
 181 }
 182
 183 /*
 184  * hammer snapls [<path> ...]
 185  *
 186  * If no arguments are specified snapshots for the PFS containing the
 187  * current directory are listed.
 188  */
 189 void
 190 hammer_cmd_snapls(char **av, int ac)
 191 {
 192         int i;
 193
 194         for (i = 0; i < ac; ++i)
 195                 snapshot_ls(av[i]);
 196         if (ac == 0)
 197                 snapshot_ls(".");
 198 }
 199
 200 /*
 201  * hammer snaprm {<path> | <transid>} ...
 202  */
 203 void
 204 hammer_cmd_snaprm(char **av, int ac)
 205 {
 206         struct stat st;
 207         char linkbuf[1024];
 208         intmax_t tid;
 209         int fsfd = -1;
 210         int i;
 211         char *dirpath;
 212         char *ptr;
 213
 214         for (i = 0; i < ac; ++i) {
 215                 if (lstat(av[i], &st) < 0) {
 216                         tid = strtoull(av[i], &ptr, 16);
 217                         if (*ptr) {
 218                                 err(2, "hammer snaprm: not a file or tid: %s",
 219                                     av[i]);
 220                                 /* not reached */
 221                         }
 222                         if (fsfd < 0)
 223                                 fsfd = open(".", O_RDONLY);
 224                         snapshot_del(fsfd, tid);
 225                 } else if (S_ISDIR(st.st_mode)) {
 226                         if (fsfd >= 0)
 227                                 close(fsfd);
 228                         fsfd = open(av[i], O_RDONLY);
 229                         if (fsfd < 0) {
 230                                 err(2, "hammer snaprm: cannot open dir %s",
 231                                     av[i]);
 232                                 /* not reached */
 233                         }
 234                 } else if (S_ISLNK(st.st_mode)) {
 235                         dirpath = dirpart(av[i]);
 236                         bzero(linkbuf, sizeof(linkbuf));
 237                         if (readlink(av[i], linkbuf, sizeof(linkbuf) - 1) < 0) {
 238                                 err(2, "hammer snaprm: cannot read softlink: "
 239                                        "%s", av[i]);
 240                                 /* not reached */
 241                         }
 242                         if (linkbuf[0] == '/') {
 243                                 free(dirpath);
 244                                 dirpath = dirpart(linkbuf);
 245                         } else {
 246                                 asprintf(&ptr, "%s/%s", dirpath, linkbuf);
 247                                 free(dirpath);
 248                                 dirpath = dirpart(ptr);
 249                         }
 250
 251                         if (fsfd >= 0)
 252                                 close(fsfd);
 253                         fsfd = open(dirpath, O_RDONLY);
 254                         if (fsfd < 0) {
 255                                 err(2, "hammer snaprm: cannot open dir %s",
 256                                     dirpath);
 257                                 /* not reached */
 258                         }
 259
 260                         if ((ptr = strrchr(linkbuf, '@')) &&
 261                             ptr > linkbuf && ptr[-1] == '@') {
 262                                 tid = strtoull(ptr + 1, NULL, 16);
 263                                 snapshot_del(fsfd, tid);
 264                         }
 265                         remove(av[i]);
 266                         free(dirpath);
 267                 } else {
 268                         err(2, "hammer snaprm: not directory or snapshot "
 269                                "softlink: %s", av[i]);
 270                         /* not reached */
 271                 }
 272         }
 273         if (fsfd >= 0)
 274                 close(fsfd);
 275 }
 276
 277 /*
 278  * snapshot <softlink-dir>
 279  * snapshot <filesystem> <softlink-dir> [<note>]
 280  */
 281 void
 282 hammer_cmd_snapshot(char **av, int ac)
 283 {
 284         const char *filesystem;
 285         const char *softlink_dir;
 286         char *softlink_fmt;
 287         struct statfs buf;
 288         struct stat st;
 289         struct hammer_ioc_synctid synctid;
 290         char *from;
 291         char *to;
 292         char *note = NULL;
 293
 294         if (ac == 1) {
 295                 filesystem = NULL;
 296                 softlink_dir = av[0];
 297         } else if (ac == 2) {
 298                 filesystem = av[0];
 299                 softlink_dir = av[1];
 300         } else if (ac == 3) {
 301                 filesystem = av[0];
 302                 softlink_dir = av[1];
 303                 note = av[2];
 304         } else {
 305                 snapshot_usage(1);
 306                 /* not reached */
 307                 softlink_dir = NULL;
 308                 filesystem = NULL;
 309         }
 310
 311         if (stat(softlink_dir, &st) == 0) {
 312                 if (!S_ISDIR(st.st_mode))
 313                         err(2, "File %s already exists", softlink_dir);
 314
 315                 if (filesystem == NULL) {
 316                         if (statfs(softlink_dir, &buf) != 0) {
 317                                 err(2, "Unable to determine filesystem of %s",
 318                                     softlink_dir);
 319                         }
 320                         filesystem = buf.f_mntonname;
 321                 }
 322
 323                 softlink_fmt = malloc(strlen(softlink_dir) + 1 + 1 +
 324                                       sizeof(DEFAULT_SNAPSHOT_NAME));
 325                 if (softlink_fmt == NULL)
 326                         err(2, "Failed to allocate string");
 327
 328                 strcpy(softlink_fmt, softlink_dir);
 329                 if (softlink_fmt[strlen(softlink_fmt)-1] != '/')
 330                         strcat(softlink_fmt, "/");
 331                 strcat(softlink_fmt, DEFAULT_SNAPSHOT_NAME);
 332         } else {
 333                 softlink_fmt = strdup(softlink_dir);
 334
 335                 if (filesystem == NULL) {
 336                         /*
 337                          * strip-off last '/path' segment to get the softlink
 338                          * directory, which we need to determine the filesystem
 339                          * we are on.
 340                          */
 341                         char *pos = strrchr(softlink_fmt, '/');
 342                         if (pos != NULL)
 343                                 *pos = '\0';
 344
 345                         if (stat(softlink_fmt, &st) != 0 ||
 346                             !S_ISDIR(st.st_mode)) {
 347                                 err(2, "Unable to determine softlink dir %s",
 348                                     softlink_fmt);
 349                         }
 350                         if (statfs(softlink_fmt, &buf) != 0) {
 351                                 err(2, "Unable to determine filesystem of %s",
 352                                     softlink_fmt);
 353                         }
 354                         filesystem = buf.f_mntonname;
 355
 356                         /* restore '/' */
 357                         if (pos != NULL)
 358                                 *pos = '/';
 359                 }
 360         }
 361
 362         /*
 363          * Synctid
 364          */
 365         bzero(&synctid, sizeof(synctid));
 366         synctid.op = HAMMER_SYNCTID_SYNC2;
 367
 368         int fd = open(filesystem, O_RDONLY);
 369         if (fd < 0)
 370                 err(2, "Unable to open %s", filesystem);
 371         if (ioctl(fd, HAMMERIOC_SYNCTID, &synctid) < 0)
 372                 err(2, "Synctid %s failed", filesystem);
 373
 374         asprintf(&from, "%s/@@0x%016jx", filesystem, (uintmax_t)synctid.tid);
 375         if (from == NULL)
 376                 err(2, "Couldn't generate string");
 377
 378         int sz = strlen(softlink_fmt) + 50;
 379         to = malloc(sz);
 380         if (to == NULL)
 381                 err(2, "Failed to allocate string");
 382
 383         time_t t = time(NULL);
 384         if (strftime(to, sz, softlink_fmt, localtime(&t)) == 0)
 385                 err(2, "String buffer too small");
 386
 387         asprintf(&from, "%s/@@0x%016jx", filesystem, (uintmax_t)synctid.tid);
 388
 389         snapshot_add(fd, from, to, note, synctid.tid);
 390
 391         close(fd);
 392         printf("%s\n", to);
 393
 394         free(softlink_fmt);
 395         free(from);
 396         free(to);
 397 }
 398
 399 static
 400 void
 401 snapshot_add(int fd, const char *fsym, const char *tsym, const char *label,
 402              hammer_tid_t tid)
 403 {
 404         struct hammer_ioc_version version;
 405         struct hammer_ioc_snapshot snapshot;
 406
 407         bzero(&version, sizeof(version));
 408         bzero(&snapshot, sizeof(snapshot));
 409
 410         /*
 411          * For HAMMER filesystem v3+ the snapshot is recorded in meta-data.
 412          */
 413         if (ioctl(fd, HAMMERIOC_GET_VERSION, &version) == 0 &&
 414             version.cur_version >= 3) {
 415                 snapshot.index = 0;
 416                 snapshot.count = 1;
 417                 snapshot.snaps[0].tid = tid;
 418                 snapshot.snaps[0].ts = time(NULL) * 1000000ULL;
 419                 if (label) {
 420                         snprintf(snapshot.snaps[0].label,
 421                                  sizeof(snapshot.snaps[0].label),
 422                                  "%s",
 423                                  label);
 424                 }
 425                 if (ioctl(fd, HAMMERIOC_ADD_SNAPSHOT, &snapshot) < 0) {
 426                         err(2, "Unable to create snapshot");
 427                 } else if (snapshot.head.error &&
 428                            snapshot.head.error != EEXIST) {
 429                         errx(2, "Unable to create snapshot: %s\n",
 430                                 strerror(snapshot.head.error));
 431                 }
 432         }
 433
 434         /*
 435          * Create a symlink for the snapshot.  If a file exists with the same
 436          * name the new symlink will replace it.
 437          */
 438         if (fsym && tsym) {
 439                 remove(tsym);
 440                 if (symlink(fsym, tsym) < 0) {
 441                         err(2, "Unable to create symlink %s", tsym);
 442                 }
 443         }
 444 }
 445
 446 static
 447 void
 448 snapshot_ls(const char *path)
 449 {
 450         /*struct hammer_ioc_version version;*/
 451         struct hammer_ioc_snapshot snapshot;
 452         struct hammer_ioc_pseudofs_rw pfs;
 453         struct hammer_snapshot_data *snap;
 454         struct tm *tp;
 455         time_t t;
 456         u_int32_t i;
 457         int fd;
 458         char snapts[64];
 459
 460         fd = open(path, O_RDONLY);
 461         if (fd < 0) {
 462                 err(2, "hammer snapls: cannot open %s", path);
 463                 /* not reached */
 464         }
 465
 466         bzero(&pfs, sizeof(pfs));
 467         pfs.pfs_id = -1;
 468         pfs.bytes = sizeof(struct hammer_pseudofs_data);
 469         if (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pfs) < 0) {
 470                 err(2, "hammer snapls: cannot retrieve PFS info on %s", path);
 471                 /* not reached */
 472         }
 473
 474         printf("Snapshots on PFS #%d\n", pfs.pfs_id);
 475
 476         bzero(&snapshot, sizeof(snapshot));
 477         do {
 478                 if (ioctl(fd, HAMMERIOC_GET_SNAPSHOT, &snapshot) < 0) {
 479                         err(2, "hammer snapls: %s: not HAMMER fs or "
 480                                 "version < 3", path);
 481                         /* not reached */
 482                 }
 483                 for (i = 0; i < snapshot.count; ++i) {
 484                         snap = &snapshot.snaps[i];
 485
 486                         t = snap->ts / 1000000ULL;
 487                         tp = localtime(&t);
 488                         strftime(snapts, sizeof(snapts),
 489                                  "%Y-%m-%d %H:%M:%S %Z", tp);
 490                         printf("0x%016jx\t%s\t%s\n",
 491                                 (uintmax_t)snap->tid, snapts, snap->label);
 492                 }
 493         } while (snapshot.head.error == 0 && snapshot.count);
 494 }
 495
 496 static
 497 void
 498 snapshot_del(int fsfd, hammer_tid_t tid)
 499 {
 500         struct hammer_ioc_snapshot snapshot;
 501         struct hammer_ioc_version version;
 502
 503         bzero(&version, sizeof(version));
 504
 505         if (ioctl(fsfd, HAMMERIOC_GET_VERSION, &version) < 0) {
 506                 err(2, "hammer snaprm 0x%016jx", (uintmax_t)tid);
 507         }
 508         if (version.cur_version < 3) {
 509                 errx(2, "hammer snaprm 0x%016jx: You must upgrade to version "
 510                         " 3 to use this directive", (uintmax_t)tid);
 511         }
 512
 513         bzero(&snapshot, sizeof(snapshot));
 514         snapshot.count = 1;
 515         snapshot.snaps[0].tid = tid;
 516
 517         /*
 518          * Do not abort if we are unable to remove the meta-data.
 519          */
 520         if (ioctl(fsfd, HAMMERIOC_DEL_SNAPSHOT, &snapshot) < 0) {
 521                 err(2, "hammer snaprm 0x%016jx",
 522                       (uintmax_t)tid);
 523         } else if (snapshot.head.error == ENOENT) {
 524                 fprintf(stderr, "Warning: hammer snaprm 0x%016jx: "
 525                                 "meta-data not found\n",
 526                         (uintmax_t)tid);
 527         } else if (snapshot.head.error) {
 528                 fprintf(stderr, "Warning: hammer snaprm 0x%016jx: %s\n",
 529                         (uintmax_t)tid, strerror(snapshot.head.error));
 530         }
 531 }
 532
 533 static
 534 void
 535 snapshot_usage(int exit_code)
 536 {
 537         fprintf(stderr,
 538     "hammer snap <path> [<note>]\t\tcreate snapshot & link, points to \n"
 539                                 "\t\t\t\t\tbase of PFS mount\n"
 540     "hammer snaplo <path> [<note>]\t\tcreate snapshot & link, points to \n"
 541                                 "\t\t\t\t\ttarget dir\n"
 542     "hammer snapq <dir> [<note>]\t\tcreate snapshot, output path to stdout\n"
 543     "hammer snaprm {<path> | <transid>} ...\tdelete snapshots\n"
 544     "hammer snapls [<path> ...]\t\tlist available snapshots\n"
 545     "\n"
 546     "NOTE: Snapshots are created in filesystem meta-data, any directory\n"
 547     "      in a HAMMER filesystem or PFS may be specified.  If the path\n"
 548     "      specified does not exist this function will also create a\n"
 549     "      softlink.\n"
 550     "\n"
 551     "      When deleting snapshots transaction ids may be directly specified\n"
 552     "      or file paths to snapshot softlinks may be specified.  If a\n"
 553     "      softlink is specified the softlink will also be deleted.\n"
 554     "\n"
 555     "NOTE: The old 'hammer snapshot [<filesystem>] <snapshot-dir>' form\n"
 556     "      is still accepted but is a deprecated form.  This form will\n"
 557     "      work for older hammer versions.  The new forms only work for\n"
 558     "      HAMMER version 3 or later filesystems.  HAMMER can be upgraded\n"
 559     "      to version 3 in-place.\n"
 560         );
 561         exit(exit_code);
 562 }
 563
 564 static
 565 char *
 566 dirpart(const char *path)
 567 {
 568         const char *ptr;
 569         char *res;
 570
 571         ptr = strrchr(path, '/');
 572         if (ptr) {
 573                 while (ptr > path && ptr[-1] == '/')
 574                         --ptr;
 575                 if (ptr == path)
 576                         ptr = NULL;
 577         }
 578         if (ptr == NULL) {
 579                 path = ".";
 580                 ptr = path + 1;
 581         }
 582         res = malloc(ptr - path + 1);
 583         bcopy(path, res, ptr - path);
 584         res[ptr - path] = 0;
 585         return(res);
 586 }