usr.bin/undo/undo.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/usr.bin/undo/undo.c,v 1.6 2008/07/17 21:34:47 thomas Exp $
  35  */
  36 /*
  37  * UNDO - retrieve an older version of a file.
  38  */
  39
  40 #include <sys/types.h>
  41 #include <sys/stat.h>
  42 #include <sys/wait.h>
  43 #include <sys/tree.h>
  44 #include <sys/param.h>
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include <stdarg.h>
  48 #include <string.h>
  49 #include <unistd.h>
  50 #include <fcntl.h>
  51 #include <errno.h>
  52 #include <vfs/hammer/hammer_disk.h>
  53 #include <vfs/hammer/hammer_ioctl.h>
  54
  55 /*
  56  * Sorted list of transaction ids
  57  */
  58 struct undo_hist_entry;
  59 RB_HEAD(undo_hist_entry_rb_tree, undo_hist_entry);
  60 RB_PROTOTYPE2(undo_hist_entry_rb_tree, undo_hist_entry, rbnode,
  61         undo_hist_entry_compare, hammer_tid_t);
  62
  63 struct undo_hist_entry {
  64         RB_ENTRY(undo_hist_entry) rbnode;
  65         struct hammer_ioc_hist_entry tse;
  66         ino_t inum;
  67 };
  68
  69 enum undo_type { TYPE_FILE, TYPE_DIFF, TYPE_RDIFF, TYPE_HISTORY };
  70 enum undo_cmd { CMD_DUMP, CMD_ITERATEALL };
  71
  72 #define UNDO_FLAG_MULT          0x0001
  73 #define UNDO_FLAG_INOCHG        0x0002
  74 #define UNDO_FLAG_SETTID1       0x0004
  75 #define UNDO_FLAG_SETTID2       0x0008
  76
  77 static int undo_hist_entry_compare(struct undo_hist_entry *he1,
  78                     struct undo_hist_entry *he2);
  79 static void doiterate(const char *filename, const char *outFileName,
  80                    const char *outFilePostfix, int flags,
  81                    struct hammer_ioc_hist_entry ts1,
  82                    struct hammer_ioc_hist_entry ts2,
  83                    enum undo_cmd cmd, enum undo_type type);
  84 static void dogenerate(const char *filename, const char *outFileName,
  85                    const char *outFilePostfix,
  86                    int flags, int idx, enum undo_type type,
  87                    struct hammer_ioc_hist_entry ts1,
  88                    struct hammer_ioc_hist_entry ts2);
  89 static void collect_history(int fd, int *error,
  90                    struct undo_hist_entry_rb_tree *tse_tree);
  91 static void collect_dir_history(const char *filename, int *error,
  92                    struct undo_hist_entry_rb_tree *dir_tree);
  93 static void clean_tree(struct undo_hist_entry_rb_tree *tree);
  94 static hammer_tid_t parse_delta_time(const char *timeStr, int *flags,
  95                    int ind_flag);
  96 static void runcmd(int fd, const char *cmd, ...);
  97 static char *timestamp(hammer_ioc_hist_entry_t hen);
  98 static void usage(void);
  99
 100 static int VerboseOpt;
 101
 102 RB_GENERATE2(undo_hist_entry_rb_tree, undo_hist_entry, rbnode,
 103         undo_hist_entry_compare, hammer_tid_t, tse.tid);
 104
 105
 106 int
 107 main(int ac, char **av)
 108 {
 109         const char *outFileName = NULL;
 110         const char *outFilePostfix = NULL;
 111         enum undo_cmd cmd;
 112         enum undo_type type;
 113         struct hammer_ioc_hist_entry ts1;
 114         struct hammer_ioc_hist_entry ts2;
 115         int c;
 116         int count_t;
 117         int flags;
 118
 119         bzero(&ts1, sizeof(ts1));
 120         bzero(&ts2, sizeof(ts2));
 121
 122         cmd = CMD_DUMP;
 123         type = TYPE_FILE;
 124         count_t = 0;
 125         flags = 0;
 126
 127         while ((c = getopt(ac, av, "adDiuvo:t:")) != -1) {
 128                 switch(c) {
 129                 case 'd':
 130                         type = TYPE_DIFF;
 131                         break;
 132                 case 'D':
 133                         type = TYPE_RDIFF;
 134                         break;
 135                 case 'i':
 136                         if (type != TYPE_FILE)
 137                                 usage();
 138                         type = TYPE_HISTORY;
 139                         cmd = CMD_ITERATEALL;
 140                         break;
 141                 case 'a':
 142                         cmd = CMD_ITERATEALL;
 143                         break;
 144                 case 'u':
 145                         outFilePostfix = ".undo";
 146                         break;
 147                 case 'v':
 148                         ++VerboseOpt;
 149                         break;
 150                 case 'o':
 151                         outFileName = optarg;
 152                         break;
 153                 case 't':
 154                         /*
 155                          * Parse one or two -t options.  If two are specified
 156                          * -d is implied (but may be overridden)
 157                          */
 158                         ++count_t;
 159                         if (count_t == 1) {
 160                                 ts1.tid = parse_delta_time(optarg, &flags,
 161                                                            UNDO_FLAG_SETTID1);
 162                         } else if (count_t == 2) {
 163                                 ts2.tid = parse_delta_time(optarg, &flags,
 164                                                            UNDO_FLAG_SETTID2);
 165                                 if (type == TYPE_FILE)
 166                                         type = TYPE_DIFF;
 167                         } else {
 168                                 usage();
 169                         }
 170                         break;
 171                 default:
 172                         usage();
 173                         /* NOT REACHED */
 174                         break;
 175                 }
 176         }
 177
 178         /*
 179          * Option validation
 180          */
 181         if (outFileName && outFilePostfix) {
 182                 fprintf(stderr, "The -o option may not be combined with -u\n");
 183                 usage();
 184         }
 185
 186         ac -= optind;
 187         av += optind;
 188         if (ac > 1)
 189                 flags |= UNDO_FLAG_MULT;
 190
 191         if (ac == 0)
 192                 usage();
 193
 194         /*
 195          * Validate the output template, if specified.
 196          */
 197         if (outFileName && (flags & UNDO_FLAG_MULT)) {
 198                 const char *ptr = outFileName;
 199                 int didStr = 0;
 200
 201                 while ((ptr = strchr(ptr, '%')) != NULL) {
 202                         if (ptr[1] == 's') {
 203                                 if (didStr) {
 204                                         fprintf(stderr, "Malformed output "
 205                                                         "template\n");
 206                                         usage();
 207                                 }
 208                                 didStr = 1;
 209                                 ++ptr;
 210                         } else if (ptr[1] != '%') {
 211                                 fprintf(stderr, "Malformed output template\n");
 212                                 usage();
 213                         } else {
 214                                 ptr += 2;
 215                         }
 216                 }
 217         }
 218
 219         while (ac) {
 220                 doiterate(*av, outFileName, outFilePostfix,
 221                           flags, ts1, ts2, cmd, type);
 222                 ++av;
 223                 --ac;
 224         }
 225         return(0);
 226 }
 227
 228 /*
 229  * Iterate through a file's history.  If cmd == CMD_DUMP we take the
 230  * next-to-last transaction id, unless another given.  Otherwise if
 231  * cmd == CMD_ITERATEALL we scan all transaction ids.
 232  *
 233  * Also iterate through the directory's history to locate other inodes that
 234  * used the particular file name.
 235  */
 236 static
 237 void
 238 doiterate(const char *filename, const char *outFileName,
 239           const char *outFilePostfix, int flags,
 240           struct hammer_ioc_hist_entry ts1,
 241           struct hammer_ioc_hist_entry ts2,
 242           enum undo_cmd cmd, enum undo_type type)
 243 {
 244         struct undo_hist_entry_rb_tree dir_tree;
 245         struct undo_hist_entry_rb_tree tse_tree;
 246         struct undo_hist_entry *tse1;
 247         struct undo_hist_entry *tse2;
 248         struct hammer_ioc_hist_entry tid_max;
 249         struct stat sb;
 250         char *path = NULL;
 251         int i;
 252         int fd;
 253         int error;
 254
 255         RB_INIT(&dir_tree);
 256         RB_INIT(&tse_tree);
 257
 258         tid_max.tid = HAMMER_MAX_TID;
 259         tid_max.time32 = 0;
 260
 261         /*
 262          * Use the directory history to locate all possible versions of
 263          * the file.
 264          */
 265         collect_dir_history(filename, &error, &dir_tree);
 266         RB_FOREACH(tse1, undo_hist_entry_rb_tree, &dir_tree) {
 267                 asprintf(&path, "%s@@0x%016jx", filename, (uintmax_t)tse1->tse.tid);
 268                 if (stat(path, &sb) == 0 && sb.st_mode & S_IFIFO) {
 269                         fprintf(stderr, "Warning: fake transaction id 0x%016jx\n", (uintmax_t)tse1->tse.tid);
 270                         continue;
 271                 }
 272                 if ((fd = open(path, O_RDONLY)) > 0) {
 273                         collect_history(fd, &error, &tse_tree);
 274                         close(fd);
 275                 }
 276                 free(path);
 277         }
 278         if ((fd = open(filename, O_RDONLY)) > 0) {
 279                 collect_history(fd, &error, &tse_tree);
 280                 close(fd);
 281         }
 282         if (cmd == CMD_DUMP) {
 283                 if ((ts1.tid == 0 ||
 284                      flags & (UNDO_FLAG_SETTID1|UNDO_FLAG_SETTID2)) &&
 285                     RB_EMPTY(&tse_tree)) {
 286                         if ((fd = open(filename, O_RDONLY)) > 0) {
 287                                 collect_history(fd, &error, &tse_tree);
 288                                 close(fd);
 289                         }
 290                 }
 291                 /*
 292                  * Find entry if tid set to placeholder index
 293                  */
 294                 if (flags & UNDO_FLAG_SETTID1){
 295                         tse1 = RB_MAX(undo_hist_entry_rb_tree, &tse_tree);
 296                         while (tse1 && ts1.tid--) {
 297                                 tse1 = RB_PREV(undo_hist_entry_rb_tree,
 298                                                &tse_tree, tse1);
 299                         }
 300                         if (tse1)
 301                                 ts1 = tse1->tse;
 302                         else
 303                                 ts1.tid = 0;
 304                 }
 305                 if (flags & UNDO_FLAG_SETTID2){
 306                         tse2 = RB_MAX(undo_hist_entry_rb_tree, &tse_tree);
 307                         while (tse2 && ts2.tid--) {
 308                                 tse2 = RB_PREV(undo_hist_entry_rb_tree,
 309                                                &tse_tree, tse2);
 310                         }
 311                         if (tse2)
 312                                 ts2 = tse2->tse;
 313                         else
 314                                 ts2.tid = 0;
 315                 }
 316
 317                 /*
 318                  * Single entry, most recent prior to current
 319                  */
 320                 if (ts1.tid == 0) {
 321                         tse2 = RB_MAX(undo_hist_entry_rb_tree, &tse_tree);
 322                         if (tse2) {
 323                                 ts2 = tse2->tse;
 324                                 tse1 = RB_PREV(undo_hist_entry_rb_tree,
 325                                                &tse_tree, tse2);
 326                                 if (tse1)
 327                                         ts1 = tse1->tse;
 328                         }
 329                 }
 330                 if (ts1.tid == 0) {
 331                         printf("%s: No UNDO history found\n", filename);
 332                 } else {
 333                         dogenerate(filename,
 334                                    outFileName, outFilePostfix,
 335                                    0, 0, type,
 336                                    ts1, ts2);
 337                 }
 338         } else if (RB_ROOT(&tse_tree)) {
 339                 /*
 340                  * Iterate entire history
 341                  */
 342                 printf("%s: ITERATE ENTIRE HISTORY\n", filename);
 343
 344                 tse1 = NULL;
 345                 i = 0;
 346                 RB_FOREACH(tse2, undo_hist_entry_rb_tree, &tse_tree) {
 347                         if (tse1) {
 348                                 dogenerate(filename,
 349                                            outFileName, outFilePostfix,
 350                                            flags, i, type,
 351                                            tse1->tse, tse2->tse);
 352                         }
 353                         if (tse1 && tse2->inum != tse1->inum)
 354                                 flags |= UNDO_FLAG_INOCHG;
 355                         else
 356                                 flags &= ~UNDO_FLAG_INOCHG;
 357                         tse1 = tse2;
 358                         ++i;
 359                 }
 360                 /*
 361                  * There is no delta to print for the last pair,
 362                  * because they are identical.
 363                  */
 364                 if (type != TYPE_DIFF && type != TYPE_RDIFF) {
 365                         dogenerate(filename,
 366                                    outFileName, outFilePostfix,
 367                                    flags, i, type,
 368                                    tse1->tse, tid_max);
 369                 }
 370         } else {
 371                 printf("%s: ITERATE ENTIRE HISTORY: %s\n",
 372                        filename, strerror(error));
 373         }
 374         clean_tree(&dir_tree);
 375         clean_tree(&tse_tree);
 376 }
 377
 378 /*
 379  * Generate output for a file as-of ts1 (ts1 may be 0!), if diffing then
 380  * through ts2.
 381  */
 382 static
 383 void
 384 dogenerate(const char *filename, const char *outFileName,
 385            const char *outFilePostfix,
 386            int flags, int idx, enum undo_type type,
 387            struct hammer_ioc_hist_entry ts1,
 388            struct hammer_ioc_hist_entry ts2)
 389 {
 390         struct stat st;
 391         const char *elm;
 392         char *ipath1 = NULL;
 393         char *ipath2 = NULL;
 394         FILE *fi;
 395         FILE *fp;
 396         char *buf;
 397         char *path;
 398         time_t t;
 399         struct tm *tp;
 400         char datestr[64];
 401         int n;
 402
 403         buf = malloc(8192);
 404
 405         /*
 406          * Open the input file.  If ts1 is 0 try to locate the most recent
 407          * version of the file prior to the current version.
 408          */
 409         if (ts1.tid == 0)
 410                 asprintf(&ipath1, "%s", filename);
 411         else
 412                 asprintf(&ipath1, "%s@@0x%016jx", filename, (uintmax_t)ts1.tid);
 413
 414         if (ts2.tid == 0)
 415                 asprintf(&ipath2, "%s", filename);
 416         else
 417                 asprintf(&ipath2, "%s@@0x%016jx", filename, (uintmax_t)ts2.tid);
 418
 419         if (lstat(ipath1, &st) < 0 && lstat(ipath2, &st) < 0) {
 420                 if (idx == 0 || VerboseOpt) {
 421                         fprintf(stderr, "Unable to access either %s or %s\n",
 422                                 ipath1, ipath2);
 423                 }
 424                 free(ipath1);
 425                 free(ipath2);
 426                 goto done;
 427         }
 428
 429         /*
 430          * elm is the last component of the input file name
 431          */
 432         if ((elm = strrchr(filename, '/')) != NULL)
 433                 ++elm;
 434         else
 435                 elm = filename;
 436
 437         /*
 438          * Where do we stuff our output?
 439          */
 440         if (outFileName) {
 441                 if (flags & UNDO_FLAG_MULT) {
 442                         asprintf(&path, outFileName, elm);
 443                         fp = fopen(path, "w");
 444                         if (fp == NULL) {
 445                                 perror(path);
 446                                 exit(1);
 447                         }
 448                         free(path);
 449                 } else {
 450                         fp = fopen(outFileName, "w");
 451                         if (fp == NULL) {
 452                                 perror(outFileName);
 453                                 exit(1);
 454                         }
 455                 }
 456         } else if (outFilePostfix) {
 457                 if (idx >= 0) {
 458                         asprintf(&path, "%s%s.%04d", filename,
 459                                  outFilePostfix, idx);
 460                 } else {
 461                         asprintf(&path, "%s%s", filename, outFilePostfix);
 462                 }
 463                 fp = fopen(path, "w");
 464                 if (fp == NULL) {
 465                         perror(path);
 466                         exit(1);
 467                 }
 468                 free(path);
 469         } else {
 470                 if ((flags & UNDO_FLAG_MULT) && type == TYPE_FILE) {
 471                         if (idx >= 0) {
 472                                 printf("\n>>> %s %04d 0x%016jx %s\n\n",
 473                                        filename, idx, (uintmax_t)ts1.tid,
 474                                        timestamp(&ts1));
 475                         } else {
 476                                 printf("\n>>> %s ---- 0x%016jx %s\n\n",
 477                                        filename, (uintmax_t)ts1.tid,
 478                                        timestamp(&ts1));
 479                         }
 480                 } else if (idx >= 0 && type == TYPE_FILE) {
 481                         printf("\n>>> %s %04d 0x%016jx %s\n\n",
 482                                filename, idx, (uintmax_t)ts1.tid,
 483                                timestamp(&ts1));
 484                 }
 485                 fp = stdout;
 486         }
 487
 488         switch(type) {
 489         case TYPE_FILE:
 490                 if ((fi = fopen(ipath1, "r")) != NULL) {
 491                         while ((n = fread(buf, 1, 8192, fi)) > 0)
 492                                 fwrite(buf, 1, n, fp);
 493                         fclose(fi);
 494                 }
 495                 break;
 496         case TYPE_DIFF:
 497                 printf("diff -N -r -u %s %s (to %s)\n",
 498                        ipath1, ipath2, timestamp(&ts2));
 499                 fflush(stdout);
 500                 runcmd(fileno(fp), "/usr/bin/diff", "diff", "-N", "-r", "-u", ipath1, ipath2, NULL);
 501                 break;
 502         case TYPE_RDIFF:
 503                 printf("diff -N -r -u %s %s\n", ipath2, ipath1);
 504                 fflush(stdout);
 505                 runcmd(fileno(fp), "/usr/bin/diff", "diff", "-N", "-r", "-u", ipath2, ipath1, NULL);
 506                 break;
 507         case TYPE_HISTORY:
 508                 t = (time_t)ts1.time32;
 509                 tp = localtime(&t);
 510                 strftime(datestr, sizeof(datestr), "%d-%b-%Y %H:%M:%S", tp);
 511                 printf("\t0x%016jx %s", (uintmax_t)ts1.tid, datestr);
 512                 if (flags & UNDO_FLAG_INOCHG)
 513                         printf(" inode-change");
 514                 if (lstat(ipath1, &st) < 0)
 515                         printf(" file-deleted");
 516                 printf("\n");
 517                 break;
 518         }
 519
 520         if (fp != stdout)
 521                 fclose(fp);
 522 done:
 523         free(buf);
 524 }
 525
 526 static
 527 void
 528 clean_tree(struct undo_hist_entry_rb_tree *tree)
 529 {
 530         struct undo_hist_entry *tse;
 531
 532         while ((tse = RB_ROOT(tree)) != NULL) {
 533                 RB_REMOVE(undo_hist_entry_rb_tree, tree, tse);
 534                 free(tse);
 535         }
 536 }
 537
 538 static
 539 void
 540 collect_history(int fd, int *errorp, struct undo_hist_entry_rb_tree *tse_tree)
 541 {
 542         struct hammer_ioc_history hist;
 543         struct undo_hist_entry *tse;
 544         struct stat st;
 545         int istmp;
 546         int i;
 547
 548         /*
 549          * Setup
 550          */
 551         bzero(&hist, sizeof(hist));
 552         hist.beg_tid = HAMMER_MIN_TID;
 553         hist.end_tid = HAMMER_MAX_TID;
 554         hist.head.flags |= HAMMER_IOC_HISTORY_ATKEY;
 555         hist.key = 0;
 556         hist.nxt_key = HAMMER_MAX_KEY;
 557
 558         *errorp = 0;
 559
 560         if (tse_tree == NULL) {
 561                 tse_tree = malloc(sizeof(*tse_tree));
 562                 RB_INIT(tse_tree);
 563                 istmp = 1;
 564         } else {
 565                 istmp = 0;
 566         }
 567
 568         /*
 569          * Save the inode so inode changes can be reported.
 570          */
 571         st.st_ino = 0;
 572         fstat(fd, &st);
 573
 574         /*
 575          * Collect a unique set of transaction ids
 576          */
 577         if (ioctl(fd, HAMMERIOC_GETHISTORY, &hist) < 0) {
 578                 *errorp = errno;
 579                 goto done;
 580         }
 581         for (;;) {
 582                 for (i = 0; i < hist.count; ++i) {
 583                         tse = malloc(sizeof(*tse));
 584                         tse->tse = hist.hist_ary[i];
 585                         tse->inum = st.st_ino;
 586                         if (RB_INSERT(undo_hist_entry_rb_tree, tse_tree, tse)) {
 587                                 free(tse);
 588                         }
 589                 }
 590                 if (hist.head.flags & HAMMER_IOC_HISTORY_EOF)
 591                         break;
 592                 if (hist.head.flags & HAMMER_IOC_HISTORY_NEXT_KEY) {
 593                         hist.key = hist.nxt_key;
 594                         hist.nxt_key = HAMMER_MAX_KEY;
 595                 }
 596                 if (hist.head.flags & HAMMER_IOC_HISTORY_NEXT_TID)
 597                         hist.beg_tid = hist.nxt_tid;
 598                 if (ioctl(fd, HAMMERIOC_GETHISTORY, &hist) < 0) {
 599                         *errorp = errno;
 600                         break;
 601                 }
 602         }
 603
 604         /*
 605          * Cleanup
 606          */
 607 done:
 608         if (istmp) {
 609                 clean_tree(tse_tree);
 610                 free(tse_tree);
 611         }
 612 }
 613
 614 static
 615 void
 616 collect_dir_history(const char *filename, int *errorp,
 617                     struct undo_hist_entry_rb_tree *dir_tree)
 618 {
 619         char *dirname;
 620         int fd;
 621         int error;
 622
 623         *errorp = 0;
 624         if (strrchr(filename, '/')) {
 625                 dirname = strdup(filename);
 626                 *strrchr(dirname, '/') = 0;
 627         } else {
 628                 dirname = strdup(".");
 629         }
 630         if ((fd = open(dirname, O_RDONLY)) > 0) {
 631                 collect_history(fd, &error, dir_tree);
 632                 close(fd);
 633         }
 634 }
 635
 636 static
 637 hammer_tid_t
 638 parse_delta_time(const char *timeStr, int *flags, int ind_flag)
 639 {
 640         hammer_tid_t tid;
 641
 642         tid = strtoull(timeStr, NULL, 0);
 643         if (timeStr[0] == '+')
 644                 ++timeStr;
 645         if (timeStr[0] >= '0' && timeStr[0] <= '9' && timeStr[1] != 'x')
 646                 *flags |= ind_flag;
 647         return(tid);
 648 }
 649
 650 static void
 651 runcmd(int fd, const char *cmd, ...)
 652 {
 653         va_list va;
 654         pid_t pid;
 655         char **av;
 656         int ac;
 657         int i;
 658
 659         va_start(va, cmd);
 660         for (ac = 0; va_arg(va, void *) != NULL; ++ac)
 661                 ;
 662         va_end(va);
 663
 664         av = malloc((ac + 1) * sizeof(char *));
 665         va_start(va, cmd);
 666         for (i = 0; i < ac; ++i)
 667                 av[i] = va_arg(va, char *);
 668         va_end(va);
 669         av[i] = NULL;
 670
 671         if ((pid = fork()) < 0) {
 672                 perror("fork");
 673                 exit(1);
 674         } else if (pid == 0) {
 675                 if (fd != 1) {
 676                         dup2(fd, 1);
 677                         close(fd);
 678                 }
 679                 execv(cmd, av);
 680                 _exit(1);
 681         } else {
 682                 while (waitpid(pid, NULL, 0) != pid)
 683                         ;
 684         }
 685         free(av);
 686 }
 687
 688 /*
 689  * Convert tid to timestamp.
 690  */
 691 static char *
 692 timestamp(hammer_ioc_hist_entry_t hen)
 693 {
 694         static char timebuf[64];
 695         time_t t = (time_t)hen->time32;
 696         struct tm *tp;
 697
 698         tp = localtime(&t);
 699         strftime(timebuf, sizeof(timebuf), "%d-%b-%Y %H:%M:%S", tp);
 700         return(timebuf);
 701 }
 702
 703 static
 704 int
 705 undo_hist_entry_compare(struct undo_hist_entry *he1,
 706                         struct undo_hist_entry *he2)
 707 {
 708         if (he1->tse.tid < he2->tse.tid)
 709                 return(-1);
 710         if (he1->tse.tid > he2->tse.tid)
 711                 return(1);
 712         return(0);
 713 }
 714
 715 static void
 716 usage(void)
 717 {
 718         fprintf(stderr, "undo [-adDiuv] [-o outfile] "
 719                         "[-t transaction-id] [-t transaction-id] path...\n"
 720                         "    -a       Iterate all historical segments\n"
 721                         "    -d       Forward diff\n"
 722                         "    -D       Reverse diff\n"
 723                         "    -i       Dump history transaction ids\n"
 724                         "    -u       Generate .undo files\n"
 725                         "    -v       Verbose\n"
 726                         "    -o file  Output to the specified file\n"
 727                         "    -t TID   Retrieve as of transaction-id, TID\n"
 728                         "             (a second `-t TID' to diff two)\n"
 729                         "    transaction ids must be prefixed with 0x, and\n"
 730                         "    otherwise may specify an index starting at 0\n"
 731                         "    and iterating backwards through the history.\n"
 732         );
 733         exit(1);
 734 }
 735