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 extern char *find_pfs_mount(int pfsid, uuid_t parentuuid, int ismaster);
  47
  48 #define DEFAULT_SNAPSHOT_NAME "snap-%Y%m%d-%H%M"
  49
  50 static void snapshot_usage(int exit_code);
  51 static void snapshot_add(int fd, const char *fsym, const char *tsym,
  52                 const char *label, hammer_tid_t tid);
  53 static void snapshot_ls(const char *path);
  54 static void snapshot_del(int fsfd, hammer_tid_t tid);
  55 static char *dirpart(const char *path);
  56
  57 /*
  58  * hammer snap <path> [<note>]
  59  *
  60  * Path may be a directory, softlink, or non-existent (a softlink will be
  61  * created).
  62  */
  63 void
  64 hammer_cmd_snap(char **av, int ac, int tostdout, int fsbase)
  65 {
  66         struct hammer_ioc_synctid synctid;
  67         struct hammer_ioc_version version;
  68         char *dirpath;
  69         char *fsym;
  70         char *tsym;
  71         struct stat st;
  72         char note[64];
  73         int fsfd;
  74
  75         if (ac == 0 || ac > 2) {
  76                 snapshot_usage(1);
  77                 /* not reached */
  78                 exit(1);
  79         }
  80
  81         if (ac == 2)
  82                 snprintf(note, sizeof(note), "%s", av[1]);
  83         else
  84                 note[0] = 0;
  85
  86         /*
  87          * Figure out the softlink path and directory path
  88          */
  89         if (stat(av[0], &st) < 0) {
  90                 dirpath = dirpart(av[0]);
  91                 tsym = av[0];
  92         } else if (S_ISLNK(st.st_mode)) {
  93                 dirpath = dirpart(av[0]);
  94                 tsym = av[0];
  95         } else if (S_ISDIR(st.st_mode)) {
  96                 time_t t = time(NULL);
  97                 struct tm *tp;
  98                 char extbuf[64];
  99
 100                 tp = localtime(&t);
 101                 strftime(extbuf, sizeof(extbuf), DEFAULT_SNAPSHOT_NAME, tp);
 102
 103                 dirpath = strdup(av[0]);
 104                 asprintf(&tsym, "%s/%s", dirpath, extbuf);
 105         } else {
 106                 err(2, "hammer snap: File %s exists and is not a softlink\n",
 107                     av[0]);
 108                 /* not reached */
 109         }
 110
 111         /*
 112          * Get a handle on some directory in the filesystem for the
 113          * ioctl (so it is stored in the correct PFS).
 114          */
 115         fsfd = open(dirpath, O_RDONLY);
 116         if (fsfd < 0) {
 117                 err(2, "hammer snap: Cannot open directory %s\n", dirpath);
 118                 /* not reached */
 119         }
 120
 121         /*
 122          * Must be at least version 3 to use this command.
 123          */
 124         bzero(&version, sizeof(version));
 125
 126         if (ioctl(fsfd, HAMMERIOC_GET_VERSION, &version) < 0) {
 127                 err(2, "Unable to create snapshot");
 128                 /* not reached */
 129         } else if (version.cur_version < 3) {
 130                 errx(2, "Unable to create snapshot: This directive requires "
 131                         "you to upgrade\n"
 132                         "the filesystem to version 3.  "
 133                         "Use 'hammer snapshot' for legacy operation.");
 134                 /* not reached */
 135         }
 136
 137         /*
 138          * Synctid to get a transaction id for the snapshot.
 139          */
 140         bzero(&synctid, sizeof(synctid));
 141         synctid.op = HAMMER_SYNCTID_SYNC2;
 142         if (ioctl(fsfd, HAMMERIOC_SYNCTID, &synctid) < 0) {
 143                 err(2, "hammer snap: Synctid %s failed",
 144                     dirpath);
 145         }
 146         if (tostdout) {
 147                 if (strcmp(dirpath, ".") == 0 || strcmp(dirpath, "..") == 0) {
 148                         printf("%s/@@0x%016jx\n",
 149                                 dirpath, (uintmax_t)synctid.tid);
 150                 } else {
 151                         printf("%s@@0x%016jx\n",
 152                                 dirpath, (uintmax_t)synctid.tid);
 153                 }
 154                 fsym = NULL;
 155                 tsym = NULL;
 156         }
 157
 158         /*
 159          * Contents of the symlink being created.
 160          */
 161         if (fsbase) {
 162                 struct statfs buf;
 163
 164                 if (statfs(dirpath, &buf) < 0) {
 165                         err(2, "hammer snap: Cannot determine mount for %s",
 166                             dirpath);
 167                 }
 168                 asprintf(&fsym, "%s/@@0x%016jx",
 169                          buf.f_mntonname, (uintmax_t)synctid.tid);
 170         } else if (strcmp(dirpath, ".") == 0 || strcmp(dirpath, "..") == 0) {
 171                 asprintf(&fsym, "%s/@@0x%016jx",
 172                          dirpath, (uintmax_t)synctid.tid);
 173         } else {
 174                 asprintf(&fsym, "%s@@0x%016jx",
 175                          dirpath, (uintmax_t)synctid.tid);
 176         }
 177
 178         /*
 179          * Create the snapshot.
 180          */
 181         snapshot_add(fsfd, fsym, tsym, note, synctid.tid);
 182         free(dirpath);
 183 }
 184
 185 /*
 186  * hammer snapls [<path> ...]
 187  *
 188  * If no arguments are specified snapshots for the PFS containing the
 189  * current directory are listed.
 190  */
 191 void
 192 hammer_cmd_snapls(char **av, int ac)
 193 {
 194         int i;
 195
 196         for (i = 0; i < ac; ++i)
 197                 snapshot_ls(av[i]);
 198         if (ac == 0)
 199                 snapshot_ls(".");
 200 }
 201
 202 /*
 203  * hammer snaprm {<path> | <transid>} ...
 204  */
 205 void
 206 hammer_cmd_snaprm(char **av, int ac)
 207 {
 208         struct stat st;
 209         char linkbuf[1024];
 210         intmax_t tid;
 211         int fsfd = -1;
 212         int i;
 213         char *dirpath;
 214         char *ptr;
 215
 216         for (i = 0; i < ac; ++i) {
 217                 if (lstat(av[i], &st) < 0) {
 218                         tid = strtoull(av[i], &ptr, 16);
 219                         if (*ptr) {
 220                                 err(2, "hammer snaprm: not a file or tid: %s",
 221                                     av[i]);
 222                                 /* not reached */
 223                         }
 224                         if (fsfd < 0)
 225                                 fsfd = open(".", O_RDONLY);
 226                         snapshot_del(fsfd, tid);
 227                 } else if (S_ISDIR(st.st_mode)) {
 228                         if (fsfd >= 0)
 229                                 close(fsfd);
 230                         fsfd = open(av[i], O_RDONLY);
 231                         if (fsfd < 0) {
 232                                 err(2, "hammer snaprm: cannot open dir %s",
 233                                     av[i]);
 234                                 /* not reached */
 235                         }
 236                 } else if (S_ISLNK(st.st_mode)) {
 237                         dirpath = dirpart(av[i]);
 238                         bzero(linkbuf, sizeof(linkbuf));
 239                         if (readlink(av[i], linkbuf, sizeof(linkbuf) - 1) < 0) {
 240                                 err(2, "hammer snaprm: cannot read softlink: "
 241                                        "%s", av[i]);
 242                                 /* not reached */
 243                         }
 244                         if (linkbuf[0] == '/') {
 245                                 free(dirpath);
 246                                 dirpath = dirpart(linkbuf);
 247                         } else {
 248                                 asprintf(&ptr, "%s/%s", dirpath, linkbuf);
 249                                 free(dirpath);
 250                                 dirpath = dirpart(ptr);
 251                         }
 252
 253                         if (fsfd >= 0)
 254                                 close(fsfd);
 255                         fsfd = open(dirpath, O_RDONLY);
 256                         if (fsfd < 0) {
 257                                 err(2, "hammer snaprm: cannot open dir %s",
 258                                     dirpath);
 259                                 /* not reached */
 260                         }
 261
 262                         if ((ptr = strrchr(linkbuf, '@')) &&
 263                             ptr > linkbuf && ptr[-1] == '@') {
 264                                 tid = strtoull(ptr + 1, NULL, 16);
 265                                 snapshot_del(fsfd, tid);
 266                         }
 267                         remove(av[i]);
 268                         free(dirpath);
 269                 } else {
 270                         err(2, "hammer snaprm: not directory or snapshot "
 271                                "softlink: %s", av[i]);
 272                         /* not reached */
 273                 }
 274         }
 275         if (fsfd >= 0)
 276                 close(fsfd);
 277 }
 278
 279 /*
 280  * snapshot <softlink-dir>
 281  * snapshot <filesystem> <softlink-dir> [<note>]
 282  */
 283 void
 284 hammer_cmd_snapshot(char **av, int ac)
 285 {
 286         const char *filesystem;
 287         const char *softlink_dir;
 288         char *softlink_fmt;
 289         struct statfs buf;
 290         struct stat st;
 291         struct hammer_ioc_synctid synctid;
 292         char *from;
 293         char *to;
 294         char *note = NULL;
 295
 296         if (ac == 1) {
 297                 filesystem = NULL;
 298                 softlink_dir = av[0];
 299         } else if (ac == 2) {
 300                 filesystem = av[0];
 301                 softlink_dir = av[1];
 302         } else if (ac == 3) {
 303                 filesystem = av[0];
 304                 softlink_dir = av[1];
 305                 note = av[2];
 306         } else {
 307                 snapshot_usage(1);
 308                 /* not reached */
 309                 softlink_dir = NULL;
 310                 filesystem = NULL;
 311         }
 312
 313         if (stat(softlink_dir, &st) == 0) {
 314                 if (!S_ISDIR(st.st_mode))
 315                         err(2, "File %s already exists", softlink_dir);
 316
 317                 if (filesystem == NULL) {
 318                         if (statfs(softlink_dir, &buf) != 0) {
 319                                 err(2, "Unable to determine filesystem of %s",
 320                                     softlink_dir);
 321                         }
 322                         filesystem = buf.f_mntonname;
 323                 }
 324
 325                 softlink_fmt = malloc(strlen(softlink_dir) + 1 + 1 +
 326                                       sizeof(DEFAULT_SNAPSHOT_NAME));
 327                 if (softlink_fmt == NULL)
 328                         err(2, "Failed to allocate string");
 329
 330                 strcpy(softlink_fmt, softlink_dir);
 331                 if (softlink_fmt[strlen(softlink_fmt)-1] != '/')
 332                         strcat(softlink_fmt, "/");
 333                 strcat(softlink_fmt, DEFAULT_SNAPSHOT_NAME);
 334         } else {
 335                 softlink_fmt = strdup(softlink_dir);
 336
 337                 if (filesystem == NULL) {
 338                         /*
 339                          * strip-off last '/path' segment to get the softlink
 340                          * directory, which we need to determine the filesystem
 341                          * we are on.
 342                          */
 343                         char *pos = strrchr(softlink_fmt, '/');
 344                         if (pos != NULL)
 345                                 *pos = '\0';
 346
 347                         if (stat(softlink_fmt, &st) != 0 ||
 348                             !S_ISDIR(st.st_mode)) {
 349                                 err(2, "Unable to determine softlink dir %s",
 350                                     softlink_fmt);
 351                         }
 352                         if (statfs(softlink_fmt, &buf) != 0) {
 353                                 err(2, "Unable to determine filesystem of %s",
 354                                     softlink_fmt);
 355                         }
 356                         filesystem = buf.f_mntonname;
 357
 358                         /* restore '/' */
 359                         if (pos != NULL)
 360                                 *pos = '/';
 361                 }
 362         }
 363
 364         /*
 365          * Synctid
 366          */
 367         bzero(&synctid, sizeof(synctid));
 368         synctid.op = HAMMER_SYNCTID_SYNC2;
 369
 370         int fd = open(filesystem, O_RDONLY);
 371         if (fd < 0)
 372                 err(2, "Unable to open %s", filesystem);
 373         if (ioctl(fd, HAMMERIOC_SYNCTID, &synctid) < 0)
 374                 err(2, "Synctid %s failed", filesystem);
 375
 376         asprintf(&from, "%s/@@0x%016jx", filesystem, (uintmax_t)synctid.tid);
 377         if (from == NULL)
 378                 err(2, "Couldn't generate string");
 379
 380         int sz = strlen(softlink_fmt) + 50;
 381         to = malloc(sz);
 382         if (to == NULL)
 383                 err(2, "Failed to allocate string");
 384
 385         time_t t = time(NULL);
 386         if (strftime(to, sz, softlink_fmt, localtime(&t)) == 0)
 387                 err(2, "String buffer too small");
 388
 389         asprintf(&from, "%s/@@0x%016jx", filesystem, (uintmax_t)synctid.tid);
 390
 391         snapshot_add(fd, from, to, note, synctid.tid);
 392
 393         close(fd);
 394         printf("%s\n", to);
 395
 396         free(softlink_fmt);
 397         free(from);
 398         free(to);
 399 }
 400
 401 static
 402 void
 403 snapshot_add(int fd, const char *fsym, const char *tsym, const char *label,
 404              hammer_tid_t tid)
 405 {
 406         struct hammer_ioc_version version;
 407         struct hammer_ioc_snapshot snapshot;
 408
 409         bzero(&version, sizeof(version));
 410         bzero(&snapshot, sizeof(snapshot));
 411
 412         /*
 413          * For HAMMER filesystem v3+ the snapshot is recorded in meta-data.
 414          */
 415         if (ioctl(fd, HAMMERIOC_GET_VERSION, &version) == 0 &&
 416             version.cur_version >= 3) {
 417                 snapshot.index = 0;
 418                 snapshot.count = 1;
 419                 snapshot.snaps[0].tid = tid;
 420                 snapshot.snaps[0].ts = time(NULL) * 1000000ULL;
 421                 if (label) {
 422                         snprintf(snapshot.snaps[0].label,
 423                                  sizeof(snapshot.snaps[0].label),
 424                                  "%s",
 425                                  label);
 426                 }
 427                 if (ioctl(fd, HAMMERIOC_ADD_SNAPSHOT, &snapshot) < 0) {
 428                         err(2, "Unable to create snapshot");
 429                 } else if (snapshot.head.error &&
 430                            snapshot.head.error != EEXIST) {
 431                         errx(2, "Unable to create snapshot: %s\n",
 432                                 strerror(snapshot.head.error));
 433                 }
 434         }
 435
 436         /*
 437          * Create a symlink for the snapshot.  If a file exists with the same
 438          * name the new symlink will replace it.
 439          */
 440         if (fsym && tsym) {
 441                 remove(tsym);
 442                 if (symlink(fsym, tsym) < 0) {
 443                         err(2, "Unable to create symlink %s", tsym);
 444                 }
 445         }
 446 }
 447
 448 static
 449 void
 450 snapshot_ls(const char *path)
 451 {
 452         /*struct hammer_ioc_version version;*/
 453         struct hammer_ioc_info info;
 454         struct hammer_ioc_snapshot snapshot;
 455         struct hammer_ioc_pseudofs_rw pfs;
 456         struct hammer_pseudofs_data pfs_od;
 457         struct hammer_snapshot_data *snap;
 458         struct tm *tp;
 459         time_t t;
 460         u_int32_t i;
 461         int fd, ismaster;
 462         char snapts[64];
 463         char *mntpoint;
 464
 465         fd = open(path, O_RDONLY);
 466         if (fd < 0) {
 467                 err(2, "hammer snapls: cannot open %s", path);
 468                 /* not reached */
 469         }
 470
 471         bzero(&pfs, sizeof(pfs));
 472         bzero(&pfs_od, sizeof(pfs_od));
 473         pfs.pfs_id = -1;
 474         pfs.ondisk = &pfs_od;
 475         pfs.bytes = sizeof(struct hammer_pseudofs_data);
 476         if (ioctl(fd, HAMMERIOC_GET_PSEUDOFS, &pfs) < 0) {
 477                 err(2, "hammer snapls: cannot retrieve PFS info on %s", path);
 478                 /* not reached */
 479         }
 480
 481         bzero(&info, sizeof(info));
 482         if ((ioctl(fd, HAMMERIOC_GET_INFO, &info)) < 0) {
 483                 err(2, "hammer snapls: cannot retrieve HAMMER info");
 484                 /* not reached */
 485         }
 486
 487         ismaster = (pfs_od.mirror_flags & HAMMER_PFSD_SLAVE) ? 0 : 1;
 488         mntpoint = find_pfs_mount(pfs.pfs_id, info.vol_fsid, ismaster);
 489
 490         /* Note the degenerate case of PFS #0 */
 491         printf("Snapshots on %s\tPFS #%d\n",
 492             pfs.pfs_id == 0 ? path : mntpoint, pfs.pfs_id);
 493         printf("Transaction ID\t\tTimestamp\t\tNote\n");
 494
 495         if (mntpoint)
 496                 free(mntpoint);
 497
 498         bzero(&snapshot, sizeof(snapshot));
 499         do {
 500                 if (ioctl(fd, HAMMERIOC_GET_SNAPSHOT, &snapshot) < 0) {
 501                         err(2, "hammer snapls: %s: not HAMMER fs or "
 502                                 "version < 3", path);
 503                         /* not reached */
 504                 }
 505                 for (i = 0; i < snapshot.count; ++i) {
 506                         snap = &snapshot.snaps[i];
 507
 508                         t = snap->ts / 1000000ULL;
 509                         tp = localtime(&t);
 510                         strftime(snapts, sizeof(snapts),
 511                                  "%Y-%m-%d %H:%M:%S %Z", tp);
 512                         printf("0x%016jx\t%s\t%s\n",
 513                                 (uintmax_t)snap->tid, snapts,
 514                                 strlen(snap->label) ? snap->label : "-");
 515                 }
 516         } while (snapshot.head.error == 0 && snapshot.count);
 517 }
 518
 519 static
 520 void
 521 snapshot_del(int fsfd, hammer_tid_t tid)
 522 {
 523         struct hammer_ioc_snapshot snapshot;
 524         struct hammer_ioc_version version;
 525
 526         bzero(&version, sizeof(version));
 527
 528         if (ioctl(fsfd, HAMMERIOC_GET_VERSION, &version) < 0) {
 529                 err(2, "hammer snaprm 0x%016jx", (uintmax_t)tid);
 530         }
 531         if (version.cur_version < 3) {
 532                 errx(2, "hammer snaprm 0x%016jx: You must upgrade to version "
 533                         " 3 to use this directive", (uintmax_t)tid);
 534         }
 535
 536         bzero(&snapshot, sizeof(snapshot));
 537         snapshot.count = 1;
 538         snapshot.snaps[0].tid = tid;
 539
 540         /*
 541          * Do not abort if we are unable to remove the meta-data.
 542          */
 543         if (ioctl(fsfd, HAMMERIOC_DEL_SNAPSHOT, &snapshot) < 0) {
 544                 err(2, "hammer snaprm 0x%016jx",
 545                       (uintmax_t)tid);
 546         } else if (snapshot.head.error == ENOENT) {
 547                 fprintf(stderr, "Warning: hammer snaprm 0x%016jx: "
 548                                 "meta-data not found\n",
 549                         (uintmax_t)tid);
 550         } else if (snapshot.head.error) {
 551                 fprintf(stderr, "Warning: hammer snaprm 0x%016jx: %s\n",
 552                         (uintmax_t)tid, strerror(snapshot.head.error));
 553         }
 554 }
 555
 556 static
 557 void
 558 snapshot_usage(int exit_code)
 559 {
 560         fprintf(stderr,
 561     "hammer snap <path> [<note>]\t\tcreate snapshot & link, points to \n"
 562                                 "\t\t\t\t\tbase of PFS mount\n"
 563     "hammer snaplo <path> [<note>]\t\tcreate snapshot & link, points to \n"
 564                                 "\t\t\t\t\ttarget dir\n"
 565     "hammer snapq <dir> [<note>]\t\tcreate snapshot, output path to stdout\n"
 566     "hammer snaprm {<path> | <transid>} ...\tdelete snapshots\n"
 567     "hammer snapls [<path> ...]\t\tlist available snapshots\n"
 568     "\n"
 569     "NOTE: Snapshots are created in filesystem meta-data, any directory\n"
 570     "      in a HAMMER filesystem or PFS may be specified.  If the path\n"
 571     "      specified does not exist this function will also create a\n"
 572     "      softlink.\n"
 573     "\n"
 574     "      When deleting snapshots transaction ids may be directly specified\n"
 575     "      or file paths to snapshot softlinks may be specified.  If a\n"
 576     "      softlink is specified the softlink will also be deleted.\n"
 577     "\n"
 578     "NOTE: The old 'hammer snapshot [<filesystem>] <snapshot-dir>' form\n"
 579     "      is still accepted but is a deprecated form.  This form will\n"
 580     "      work for older hammer versions.  The new forms only work for\n"
 581     "      HAMMER version 3 or later filesystems.  HAMMER can be upgraded\n"
 582     "      to version 3 in-place.\n"
 583         );
 584         exit(exit_code);
 585 }
 586
 587 static
 588 char *
 589 dirpart(const char *path)
 590 {
 591         const char *ptr;
 592         char *res;
 593
 594         ptr = strrchr(path, '/');
 595         if (ptr) {
 596                 while (ptr > path && ptr[-1] == '/')
 597                         --ptr;
 598                 if (ptr == path)
 599                         ptr = NULL;
 600         }
 601         if (ptr == NULL) {
 602                 path = ".";
 603                 ptr = path + 1;
 604         }
 605         res = malloc(ptr - path + 1);
 606         bcopy(path, res, ptr - path);
 607         res[ptr - path] = 0;
 608         return(res);
 609 }