restore/symtab.c

   1 /*
   2  *      Ported to Linux's Second Extended File System as part of the
   3  *      dump and restore backup suit
   4  *      Remy Card <card@Linux.EU.Org>, 1994-1997
   5  *      Stelian Pop <pop@cybercable.fr>, 1999
   6  *
   7  */
   8
   9 /*
  10  * Copyright (c) 1983, 1993
  11  *      The Regents of the University of California.  All rights reserved.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. All advertising materials mentioning features or use of this software
  22  *    must display the following acknowledgement:
  23  *      This product includes software developed by the University of
  24  *      California, Berkeley and its contributors.
  25  * 4. Neither the name of the University nor the names of its contributors
  26  *    may be used to endorse or promote products derived from this software
  27  *    without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  39  * SUCH DAMAGE.
  40  */
  41
  42 #ifndef lint
  43 #if 0
  44 static char sccsid[] = "@(#)symtab.c    8.3 (Berkeley) 4/28/95";
  45 #endif
  46 static const char rcsid[] =
  47         "$Id: symtab.c,v 1.2 1999/10/11 12:53:24 stelian Exp $";
  48 #endif /* not lint */
  49
  50 /*
  51  * These routines maintain the symbol table which tracks the state
  52  * of the file system being restored. They provide lookup by either
  53  * name or inode number. They also provide for creation, deletion,
  54  * and renaming of entries. Because of the dynamic nature of pathnames,
  55  * names should not be saved, but always constructed just before they
  56  * are needed, by calling "myname".
  57  */
  58
  59 #include <sys/param.h>
  60 #include <sys/stat.h>
  61
  62 #ifdef  __linux__
  63 #include <sys/time.h>
  64 #include <linux/ext2_fs.h>
  65 #include <bsdcompat.h>
  66 #else   /* __linux__ */
  67 #include <ufs/ufs/dinode.h>
  68 #endif  /* __linux__ */
  69
  70 #include <errno.h>
  71 #include <fcntl.h>
  72 #include <stdio.h>
  73 #include <stdlib.h>
  74 #include <string.h>
  75 #include <unistd.h>
  76
  77 #ifdef  __linux__
  78 #include <ext2fs/ext2fs.h>
  79 #endif
  80
  81 #include "restore.h"
  82 #include "extern.h"
  83
  84 /*
  85  * The following variables define the inode symbol table.
  86  * The primary hash table is dynamically allocated based on
  87  * the number of inodes in the file system (maxino), scaled by
  88  * HASHFACTOR. The variable "entry" points to the hash table;
  89  * the variable "entrytblsize" indicates its size (in entries).
  90  */
  91 #define HASHFACTOR 5
  92 static struct entry **entry;
  93 static long entrytblsize;
  94
  95 static void              addino __P((ino_t, struct entry *));
  96 static struct entry     *lookupparent __P((char *));
  97 static void              removeentry __P((struct entry *));
  98
  99 /*
 100  * Look up an entry by inode number
 101  */
 102 struct entry *
 103 lookupino(inum)
 104         ino_t inum;
 105 {
 106         register struct entry *ep;
 107
 108         if (inum < WINO || inum >= maxino)
 109                 return (NULL);
 110         for (ep = entry[inum % entrytblsize]; ep != NULL; ep = ep->e_next)
 111                 if (ep->e_ino == inum)
 112                         return (ep);
 113         return (NULL);
 114 }
 115
 116 /*
 117  * Add an entry into the entry table
 118  */
 119 static void
 120 addino(inum, np)
 121         ino_t inum;
 122         struct entry *np;
 123 {
 124         struct entry **epp;
 125
 126         if (inum < WINO || inum >= maxino)
 127                 panic("addino: out of range %d\n", inum);
 128         epp = &entry[inum % entrytblsize];
 129         np->e_ino = inum;
 130         np->e_next = *epp;
 131         *epp = np;
 132         if (dflag)
 133                 for (np = np->e_next; np != NULL; np = np->e_next)
 134                         if (np->e_ino == inum)
 135                                 badentry(np, "duplicate inum");
 136 }
 137
 138 /*
 139  * Delete an entry from the entry table
 140  */
 141 void
 142 deleteino(inum)
 143         ino_t inum;
 144 {
 145         register struct entry *next;
 146         struct entry **prev;
 147
 148         if (inum < WINO || inum >= maxino)
 149                 panic("deleteino: out of range %d\n", inum);
 150         prev = &entry[inum % entrytblsize];
 151         for (next = *prev; next != NULL; next = next->e_next) {
 152                 if (next->e_ino == inum) {
 153                         next->e_ino = 0;
 154                         *prev = next->e_next;
 155                         return;
 156                 }
 157                 prev = &next->e_next;
 158         }
 159         panic("deleteino: %d not found\n", inum);
 160 }
 161
 162 /*
 163  * Look up an entry by name
 164  */
 165 struct entry *
 166 lookupname(name)
 167         char *name;
 168 {
 169         register struct entry *ep;
 170         register char *np, *cp;
 171         char buf[MAXPATHLEN];
 172
 173         cp = name;
 174         for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) {
 175                 for (np = buf; *cp != '/' && *cp != '\0' &&
 176                                 np < &buf[sizeof(buf)]; )
 177                         *np++ = *cp++;
 178                 if (np == &buf[sizeof(buf)])
 179                         break;
 180                 *np = '\0';
 181                 for ( ; ep != NULL; ep = ep->e_sibling)
 182                         if (strcmp(ep->e_name, buf) == 0)
 183                                 break;
 184                 if (ep == NULL)
 185                         break;
 186                 if (*cp++ == '\0')
 187                         return (ep);
 188         }
 189         return (NULL);
 190 }
 191
 192 /*
 193  * Look up the parent of a pathname
 194  */
 195 static struct entry *
 196 lookupparent(name)
 197         char *name;
 198 {
 199         struct entry *ep;
 200         char *tailindex;
 201
 202         tailindex = strrchr(name, '/');
 203         if (tailindex == NULL)
 204                 return (NULL);
 205         *tailindex = '\0';
 206         ep = lookupname(name);
 207         *tailindex = '/';
 208         if (ep == NULL)
 209                 return (NULL);
 210         if (ep->e_type != NODE)
 211                 panic("%s is not a directory\n", name);
 212         return (ep);
 213 }
 214
 215 /*
 216  * Determine the current pathname of a node or leaf
 217  */
 218 char *
 219 myname(ep)
 220         register struct entry *ep;
 221 {
 222         register char *cp;
 223         static char namebuf[MAXPATHLEN];
 224
 225         for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) {
 226                 cp -= ep->e_namlen;
 227                 memmove(cp, ep->e_name, (long)ep->e_namlen);
 228                 if (ep == lookupino(ROOTINO))
 229                         return (cp);
 230                 *(--cp) = '/';
 231                 ep = ep->e_parent;
 232         }
 233         panic("%s: pathname too long\n", cp);
 234         return(cp);
 235 }
 236
 237 /*
 238  * Unused symbol table entries are linked together on a free list
 239  * headed by the following pointer.
 240  */
 241 static struct entry *freelist = NULL;
 242
 243 /*
 244  * add an entry to the symbol table
 245  */
 246 struct entry *
 247 addentry(name, inum, type)
 248         char *name;
 249         ino_t inum;
 250         int type;
 251 {
 252         register struct entry *np, *ep;
 253
 254         if (freelist != NULL) {
 255                 np = freelist;
 256                 freelist = np->e_next;
 257                 memset(np, 0, (long)sizeof(struct entry));
 258         } else {
 259                 np = (struct entry *)calloc(1, sizeof(struct entry));
 260                 if (np == NULL)
 261                         panic("no memory to extend symbol table\n");
 262         }
 263         np->e_type = type & ~LINK;
 264         ep = lookupparent(name);
 265         if (ep == NULL) {
 266                 if (inum != ROOTINO || lookupino(ROOTINO) != NULL)
 267                         panic("bad name to addentry %s\n", name);
 268                 np->e_name = savename(name);
 269                 np->e_namlen = strlen(name);
 270                 np->e_parent = np;
 271                 addino(ROOTINO, np);
 272                 return (np);
 273         }
 274         np->e_name = savename(strrchr(name, '/') + 1);
 275         np->e_namlen = strlen(np->e_name);
 276         np->e_parent = ep;
 277         np->e_sibling = ep->e_entries;
 278         ep->e_entries = np;
 279         if (type & LINK) {
 280                 ep = lookupino(inum);
 281                 if (ep == NULL)
 282                         panic("link to non-existent name\n");
 283                 np->e_ino = inum;
 284                 np->e_links = ep->e_links;
 285                 ep->e_links = np;
 286         } else if (inum != 0) {
 287                 if (lookupino(inum) != NULL)
 288                         panic("duplicate entry\n");
 289                 addino(inum, np);
 290         }
 291         return (np);
 292 }
 293
 294 /*
 295  * delete an entry from the symbol table
 296  */
 297 void
 298 freeentry(ep)
 299         register struct entry *ep;
 300 {
 301         register struct entry *np;
 302         ino_t inum;
 303
 304         if (ep->e_flags != REMOVED)
 305                 badentry(ep, "not marked REMOVED");
 306         if (ep->e_type == NODE) {
 307                 if (ep->e_links != NULL)
 308                         badentry(ep, "freeing referenced directory");
 309                 if (ep->e_entries != NULL)
 310                         badentry(ep, "freeing non-empty directory");
 311         }
 312         if (ep->e_ino != 0) {
 313                 np = lookupino(ep->e_ino);
 314                 if (np == NULL)
 315                         badentry(ep, "lookupino failed");
 316                 if (np == ep) {
 317                         inum = ep->e_ino;
 318                         deleteino(inum);
 319                         if (ep->e_links != NULL)
 320                                 addino(inum, ep->e_links);
 321                 } else {
 322                         for (; np != NULL; np = np->e_links) {
 323                                 if (np->e_links == ep) {
 324                                         np->e_links = ep->e_links;
 325                                         break;
 326                                 }
 327                         }
 328                         if (np == NULL)
 329                                 badentry(ep, "link not found");
 330                 }
 331         }
 332         removeentry(ep);
 333         freename(ep->e_name);
 334         ep->e_next = freelist;
 335         freelist = ep;
 336 }
 337
 338 /*
 339  * Relocate an entry in the tree structure
 340  */
 341 void
 342 moveentry(ep, newname)
 343         register struct entry *ep;
 344         char *newname;
 345 {
 346         struct entry *np;
 347         char *cp;
 348
 349         np = lookupparent(newname);
 350         if (np == NULL)
 351                 badentry(ep, "cannot move ROOT");
 352         if (np != ep->e_parent) {
 353                 removeentry(ep);
 354                 ep->e_parent = np;
 355                 ep->e_sibling = np->e_entries;
 356                 np->e_entries = ep;
 357         }
 358         cp = strrchr(newname, '/') + 1;
 359         freename(ep->e_name);
 360         ep->e_name = savename(cp);
 361         ep->e_namlen = strlen(cp);
 362         if (strcmp(gentempname(ep), ep->e_name) == 0)
 363                 ep->e_flags |= TMPNAME;
 364         else
 365                 ep->e_flags &= ~TMPNAME;
 366 }
 367
 368 /*
 369  * Remove an entry in the tree structure
 370  */
 371 static void
 372 removeentry(ep)
 373         register struct entry *ep;
 374 {
 375         register struct entry *np;
 376
 377         np = ep->e_parent;
 378         if (np->e_entries == ep) {
 379                 np->e_entries = ep->e_sibling;
 380         } else {
 381                 for (np = np->e_entries; np != NULL; np = np->e_sibling) {
 382                         if (np->e_sibling == ep) {
 383                                 np->e_sibling = ep->e_sibling;
 384                                 break;
 385                         }
 386                 }
 387                 if (np == NULL)
 388                         badentry(ep, "cannot find entry in parent list");
 389         }
 390 }
 391
 392 /*
 393  * Table of unused string entries, sorted by length.
 394  *
 395  * Entries are allocated in STRTBLINCR sized pieces so that names
 396  * of similar lengths can use the same entry. The value of STRTBLINCR
 397  * is chosen so that every entry has at least enough space to hold
 398  * a "struct strtbl" header. Thus every entry can be linked onto an
 399  * appropriate free list.
 400  *
 401  * NB. The macro "allocsize" below assumes that "struct strhdr"
 402  *     has a size that is a power of two.
 403  */
 404 struct strhdr {
 405         struct strhdr *next;
 406 };
 407
 408 #define STRTBLINCR      (sizeof(struct strhdr))
 409 #define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1))
 410
 411 static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR];
 412
 413 /*
 414  * Allocate space for a name. It first looks to see if it already
 415  * has an appropriate sized entry, and if not allocates a new one.
 416  */
 417 char *
 418 savename(name)
 419         char *name;
 420 {
 421         struct strhdr *np;
 422         long len;
 423         char *cp;
 424
 425         if (name == NULL)
 426                 panic("bad name\n");
 427         len = strlen(name);
 428         np = strtblhdr[len / STRTBLINCR].next;
 429         if (np != NULL) {
 430                 strtblhdr[len / STRTBLINCR].next = np->next;
 431                 cp = (char *)np;
 432         } else {
 433                 cp = malloc((unsigned)allocsize(len));
 434                 if (cp == NULL)
 435                         panic("no space for string table\n");
 436         }
 437         (void) strcpy(cp, name);
 438         return (cp);
 439 }
 440
 441 /*
 442  * Free space for a name. The resulting entry is linked onto the
 443  * appropriate free list.
 444  */
 445 void
 446 freename(name)
 447         char *name;
 448 {
 449         struct strhdr *tp, *np;
 450
 451         tp = &strtblhdr[strlen(name) / STRTBLINCR];
 452         np = (struct strhdr *)name;
 453         np->next = tp->next;
 454         tp->next = np;
 455 }
 456
 457 /*
 458  * Useful quantities placed at the end of a dumped symbol table.
 459  */
 460 struct symtableheader {
 461         int32_t volno;
 462         int32_t stringsize;
 463         int32_t entrytblsize;
 464         time_t  dumptime;
 465         time_t  dumpdate;
 466         ino_t   maxino;
 467         int32_t ntrec;
 468 };
 469
 470 /*
 471  * dump a snapshot of the symbol table
 472  */
 473 void
 474 dumpsymtable(filename, checkpt)
 475         char *filename;
 476         long checkpt;
 477 {
 478         register struct entry *ep, *tep;
 479         register ino_t i;
 480         struct entry temp, *tentry;
 481         long mynum = 1, stroff = 0;
 482         FILE *fd;
 483         struct symtableheader hdr;
 484
 485         vprintf(stdout, "Check pointing the restore\n");
 486         if (Nflag)
 487                 return;
 488         if ((fd = fopen(filename, "w")) == NULL) {
 489                 fprintf(stderr, "fopen: %s\n", strerror(errno));
 490                 panic("cannot create save file %s for symbol table\n",
 491                         filename);
 492         }
 493         clearerr(fd);
 494         /*
 495          * Assign indices to each entry
 496          * Write out the string entries
 497          */
 498         for (i = WINO; i <= maxino; i++) {
 499                 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
 500                         ep->e_index = mynum++;
 501                         (void) fwrite(ep->e_name, sizeof(char),
 502                                (int)allocsize(ep->e_namlen), fd);
 503                 }
 504         }
 505         /*
 506          * Convert pointers to indexes, and output
 507          */
 508         tep = &temp;
 509         stroff = 0;
 510         for (i = WINO; i <= maxino; i++) {
 511                 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
 512                         memmove(tep, ep, (long)sizeof(struct entry));
 513                         tep->e_name = (char *)stroff;
 514                         stroff += allocsize(ep->e_namlen);
 515                         tep->e_parent = (struct entry *)ep->e_parent->e_index;
 516                         if (ep->e_links != NULL)
 517                                 tep->e_links =
 518                                         (struct entry *)ep->e_links->e_index;
 519                         if (ep->e_sibling != NULL)
 520                                 tep->e_sibling =
 521                                         (struct entry *)ep->e_sibling->e_index;
 522                         if (ep->e_entries != NULL)
 523                                 tep->e_entries =
 524                                         (struct entry *)ep->e_entries->e_index;
 525                         if (ep->e_next != NULL)
 526                                 tep->e_next =
 527                                         (struct entry *)ep->e_next->e_index;
 528                         (void) fwrite((char *)tep, sizeof(struct entry), 1, fd);
 529                 }
 530         }
 531         /*
 532          * Convert entry pointers to indexes, and output
 533          */
 534         for (i = 0; i < entrytblsize; i++) {
 535                 if (entry[i] == NULL)
 536                         tentry = NULL;
 537                 else
 538                         tentry = (struct entry *)entry[i]->e_index;
 539                 (void) fwrite((char *)&tentry, sizeof(struct entry *), 1, fd);
 540         }
 541         hdr.volno = checkpt;
 542         hdr.maxino = maxino;
 543         hdr.entrytblsize = entrytblsize;
 544         hdr.stringsize = stroff;
 545         hdr.dumptime = dumptime;
 546         hdr.dumpdate = dumpdate;
 547         hdr.ntrec = ntrec;
 548         (void) fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd);
 549         if (ferror(fd)) {
 550                 fprintf(stderr, "fwrite: %s\n", strerror(errno));
 551                 panic("output error to file %s writing symbol table\n",
 552                         filename);
 553         }
 554         (void) fclose(fd);
 555 }
 556
 557 /*
 558  * Initialize a symbol table from a file
 559  */
 560 void
 561 initsymtable(filename)
 562         char *filename;
 563 {
 564         char *base;
 565         long tblsize;
 566         register struct entry *ep;
 567         struct entry *baseep, *lep;
 568         struct symtableheader hdr;
 569         struct stat stbuf;
 570         register long i;
 571         int fd;
 572
 573         vprintf(stdout, "Initialize symbol table.\n");
 574         if (filename == NULL) {
 575                 entrytblsize = maxino / HASHFACTOR;
 576                 entry = (struct entry **)
 577                         calloc((unsigned)entrytblsize, sizeof(struct entry *));
 578                 if (entry == (struct entry **)NULL)
 579                         panic("no memory for entry table\n");
 580                 ep = addentry(".", ROOTINO, NODE);
 581                 ep->e_flags |= NEW;
 582                 return;
 583         }
 584         if ((fd = open(filename, O_RDONLY, 0)) < 0) {
 585                 fprintf(stderr, "open: %s\n", strerror(errno));
 586                 panic("cannot open symbol table file %s\n", filename);
 587         }
 588         if (fstat(fd, &stbuf) < 0) {
 589                 fprintf(stderr, "stat: %s\n", strerror(errno));
 590                 panic("cannot stat symbol table file %s\n", filename);
 591         }
 592         tblsize = stbuf.st_size - sizeof(struct symtableheader);
 593         base = calloc(sizeof(char), (unsigned)tblsize);
 594         if (base == NULL)
 595                 panic("cannot allocate space for symbol table\n");
 596         if (read(fd, base, (int)tblsize) < 0 ||
 597             read(fd, (char *)&hdr, sizeof(struct symtableheader)) < 0) {
 598                 fprintf(stderr, "read: %s\n", strerror(errno));
 599                 panic("cannot read symbol table file %s\n", filename);
 600         }
 601         switch (command) {
 602         case 'r':
 603                 /*
 604                  * For normal continuation, insure that we are using
 605                  * the next incremental tape
 606                  */
 607                 if (hdr.dumpdate != dumptime) {
 608                         if (hdr.dumpdate < dumptime)
 609                                 fprintf(stderr, "Incremental tape too low\n");
 610                         else
 611                                 fprintf(stderr, "Incremental tape too high\n");
 612                         done(1);
 613                 }
 614                 break;
 615         case 'R':
 616                 /*
 617                  * For restart, insure that we are using the same tape
 618                  */
 619                 curfile.action = SKIP;
 620                 dumptime = hdr.dumptime;
 621                 dumpdate = hdr.dumpdate;
 622                 if (!bflag)
 623                         newtapebuf(hdr.ntrec);
 624                 getvol(hdr.volno);
 625                 break;
 626         default:
 627                 panic("initsymtable called from command %c\n", command);
 628                 break;
 629         }
 630         maxino = hdr.maxino;
 631         entrytblsize = hdr.entrytblsize;
 632         entry = (struct entry **)
 633                 (base + tblsize - (entrytblsize * sizeof(struct entry *)));
 634         baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry));
 635         lep = (struct entry *)entry;
 636         for (i = 0; i < entrytblsize; i++) {
 637                 if (entry[i] == NULL)
 638                         continue;
 639                 entry[i] = &baseep[(long)entry[i]];
 640         }
 641         for (ep = &baseep[1]; ep < lep; ep++) {
 642                 ep->e_name = base + (long)ep->e_name;
 643                 ep->e_parent = &baseep[(long)ep->e_parent];
 644                 if (ep->e_sibling != NULL)
 645                         ep->e_sibling = &baseep[(long)ep->e_sibling];
 646                 if (ep->e_links != NULL)
 647                         ep->e_links = &baseep[(long)ep->e_links];
 648                 if (ep->e_entries != NULL)
 649                         ep->e_entries = &baseep[(long)ep->e_entries];
 650                 if (ep->e_next != NULL)
 651                         ep->e_next = &baseep[(long)ep->e_next];
 652         }
 653 }