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 <stelian@popies.net>, 1999-2000
   6  *      Stelian Pop <stelian@popies.net> - Alcôve <www.alcove.com>, 2000-2002
   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 static const char rcsid[] =
  44         "$Id: symtab.c,v 1.20 2002/11/15 09:25:42 stelian Exp $";
  45 #endif /* not lint */
  46
  47 /*
  48  * These routines maintain the symbol table which tracks the state
  49  * of the file system being restored. They provide lookup by either
  50  * name or inode number. They also provide for creation, deletion,
  51  * and renaming of entries. Because of the dynamic nature of pathnames,
  52  * names should not be saved, but always constructed just before they
  53  * are needed, by calling "myname".
  54  */
  55
  56 #include <config.h>
  57 #include <sys/param.h>
  58 #include <sys/stat.h>
  59
  60 #ifdef  __linux__
  61 #include <sys/time.h>
  62 #include <time.h>
  63 #ifdef HAVE_EXT2FS_EXT2_FS_H
  64 #include <ext2fs/ext2_fs.h>
  65 #else
  66 #include <linux/ext2_fs.h>
  67 #endif
  68 #include <bsdcompat.h>
  69 #else   /* __linux__ */
  70 #include <ufs/ufs/dinode.h>
  71 #endif  /* __linux__ */
  72
  73 #include <errno.h>
  74 #include <compaterr.h>
  75 #include <fcntl.h>
  76 #include <stdio.h>
  77 #include <stdlib.h>
  78 #include <string.h>
  79 #include <unistd.h>
  80
  81 #ifdef  __linux__
  82 #include <ext2fs/ext2fs.h>
  83 #endif
  84
  85 #include "restore.h"
  86 #include "extern.h"
  87
  88 /*
  89  * The following variables define the inode symbol table.
  90  * The primary hash table is dynamically allocated based on
  91  * the number of inodes in the file system (maxino), scaled by
  92  * HASHFACTOR. The variable "entry" points to the hash table;
  93  * the variable "entrytblsize" indicates its size (in entries).
  94  */
  95 #define HASHFACTOR 5
  96 static struct entry **entry;
  97 static long entrytblsize;
  98
  99 static void              addino __P((dump_ino_t, struct entry *));
 100 static struct entry     *lookupparent __P((char *));
 101 static void              removeentry __P((struct entry *));
 102
 103 /*
 104  * Look up an entry by inode number
 105  */
 106 struct entry *
 107 lookupino(dump_ino_t inum)
 108 {
 109         struct entry *ep;
 110
 111         if (inum < WINO || inum >= maxino)
 112                 return (NULL);
 113         for (ep = entry[inum % entrytblsize]; ep != NULL; ep = ep->e_next)
 114                 if (ep->e_ino == inum)
 115                         return (ep);
 116         return (NULL);
 117 }
 118
 119 /*
 120  * Add an entry into the entry table
 121  */
 122 static void
 123 addino(dump_ino_t inum, struct entry *np)
 124 {
 125         struct entry **epp;
 126
 127         if (inum < WINO || inum >= maxino)
 128                 panic("addino: out of range %d\n", inum);
 129         epp = &entry[inum % entrytblsize];
 130         np->e_ino = inum;
 131         np->e_next = *epp;
 132         *epp = np;
 133         if (dflag)
 134                 for (np = np->e_next; np != NULL; np = np->e_next)
 135                         if (np->e_ino == inum)
 136                                 badentry(np, "duplicate inum");
 137 }
 138
 139 /*
 140  * Delete an entry from the entry table
 141  */
 142 void
 143 deleteino(dump_ino_t inum)
 144 {
 145         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(char *name)
 167 {
 168         struct entry *ep;
 169         char *np, *cp;
 170         char buf[MAXPATHLEN];
 171
 172         cp = name;
 173         for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) {
 174                 for (np = buf; *cp != '/' && *cp != '\0' &&
 175                                 np < &buf[sizeof(buf)]; )
 176                         *np++ = *cp++;
 177                 if (np == &buf[sizeof(buf)])
 178                         break;
 179                 *np = '\0';
 180                 for ( ; ep != NULL; ep = ep->e_sibling)
 181                         if (strcmp(ep->e_name, buf) == 0)
 182                                 break;
 183                 if (ep == NULL)
 184                         break;
 185                 if (*cp++ == '\0')
 186                         return (ep);
 187         }
 188         return (NULL);
 189 }
 190
 191 /*
 192  * Look up the parent of a pathname
 193  */
 194 static struct entry *
 195 lookupparent(char *name)
 196 {
 197         struct entry *ep;
 198         char *tailindex;
 199
 200         tailindex = strrchr(name, '/');
 201         if (tailindex == NULL)
 202                 return (NULL);
 203         *tailindex = '\0';
 204         ep = lookupname(name);
 205         *tailindex = '/';
 206         if (ep == NULL)
 207                 return (NULL);
 208         if (ep->e_type != NODE)
 209                 panic("%s is not a directory\n", name);
 210         return (ep);
 211 }
 212
 213 /*
 214  * Determine the current pathname of a node or leaf
 215  */
 216 char *
 217 myname(struct entry *ep)
 218 {
 219         char *cp;
 220         static char namebuf[MAXPATHLEN];
 221
 222         for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) {
 223                 cp -= ep->e_namlen;
 224                 memmove(cp, ep->e_name, (size_t)ep->e_namlen);
 225                 if (ep == lookupino(ROOTINO))
 226                         return (cp);
 227                 *(--cp) = '/';
 228                 ep = ep->e_parent;
 229         }
 230         panic("%s: pathname too long\n", cp);
 231         return(cp);
 232 }
 233
 234 /*
 235  * Unused symbol table entries are linked together on a free list
 236  * headed by the following pointer.
 237  */
 238 static struct entry *freelist = NULL;
 239
 240 /*
 241  * add an entry to the symbol table
 242  */
 243 struct entry *
 244 addentry(char *name, dump_ino_t inum, int type)
 245 {
 246         struct entry *np, *ep;
 247
 248         if (freelist != NULL) {
 249                 np = freelist;
 250                 freelist = np->e_next;
 251                 memset(np, 0, sizeof(struct entry));
 252         } else {
 253                 np = (struct entry *)calloc(1, sizeof(struct entry));
 254                 if (np == NULL)
 255                         errx(1, "no memory to extend symbol table");
 256         }
 257         np->e_type = type & ~LINK;
 258         ep = lookupparent(name);
 259         if (ep == NULL) {
 260                 if (inum != ROOTINO || lookupino(ROOTINO) != NULL)
 261                         panic("bad name to addentry %s\n", name);
 262                 np->e_name = savename(name);
 263                 np->e_namlen = strlen(name);
 264                 np->e_parent = np;
 265                 addino(ROOTINO, np);
 266                 return (np);
 267         }
 268         np->e_name = savename(strrchr(name, '/') + 1);
 269         np->e_namlen = strlen(np->e_name);
 270         np->e_parent = ep;
 271         np->e_sibling = ep->e_entries;
 272         ep->e_entries = np;
 273         if (type & LINK) {
 274                 ep = lookupino(inum);
 275                 if (ep == NULL)
 276                         panic("link to non-existent name\n");
 277                 np->e_ino = inum;
 278                 np->e_links = ep->e_links;
 279                 ep->e_links = np;
 280         } else if (inum != 0) {
 281                 if (lookupino(inum) != NULL)
 282                         panic("duplicate entry\n");
 283                 addino(inum, np);
 284         }
 285         return (np);
 286 }
 287
 288 /*
 289  * delete an entry from the symbol table
 290  */
 291 void
 292 freeentry(struct entry *ep)
 293 {
 294         struct entry *np;
 295         dump_ino_t inum;
 296
 297         if (ep->e_flags != REMOVED)
 298                 badentry(ep, "not marked REMOVED");
 299         if (ep->e_type == NODE) {
 300                 if (ep->e_links != NULL)
 301                         badentry(ep, "freeing referenced directory");
 302                 if (ep->e_entries != NULL)
 303                         badentry(ep, "freeing non-empty directory");
 304         }
 305         if (ep->e_ino != 0) {
 306                 np = lookupino(ep->e_ino);
 307                 if (np == NULL)
 308                         badentry(ep, "lookupino failed");
 309                 if (np == ep) {
 310                         inum = ep->e_ino;
 311                         deleteino(inum);
 312                         if (ep->e_links != NULL)
 313                                 addino(inum, ep->e_links);
 314                 } else {
 315                         for (; np != NULL; np = np->e_links) {
 316                                 if (np->e_links == ep) {
 317                                         np->e_links = ep->e_links;
 318                                         break;
 319                                 }
 320                         }
 321                         if (np == NULL)
 322                                 badentry(ep, "link not found");
 323                 }
 324         }
 325         removeentry(ep);
 326         freename(ep->e_name);
 327         ep->e_next = freelist;
 328         freelist = ep;
 329 }
 330
 331 /*
 332  * Relocate an entry in the tree structure
 333  */
 334 void
 335 moveentry(struct entry *ep, char *newname)
 336 {
 337         struct entry *np;
 338         char *cp;
 339
 340         np = lookupparent(newname);
 341         if (np == NULL)
 342                 badentry(ep, "cannot move ROOT");
 343         if (np != ep->e_parent) {
 344                 removeentry(ep);
 345                 ep->e_parent = np;
 346                 ep->e_sibling = np->e_entries;
 347                 np->e_entries = ep;
 348         }
 349         cp = strrchr(newname, '/') + 1;
 350         freename(ep->e_name);
 351         ep->e_name = savename(cp);
 352         ep->e_namlen = strlen(cp);
 353         if (strcmp(gentempname(ep), ep->e_name) == 0)
 354                 ep->e_flags |= TMPNAME;
 355         else
 356                 ep->e_flags &= ~TMPNAME;
 357 }
 358
 359 /*
 360  * Remove an entry in the tree structure
 361  */
 362 static void
 363 removeentry(struct entry *ep)
 364 {
 365         struct entry *np;
 366
 367         np = ep->e_parent;
 368         if (np->e_entries == ep) {
 369                 np->e_entries = ep->e_sibling;
 370         } else {
 371                 for (np = np->e_entries; np != NULL; np = np->e_sibling) {
 372                         if (np->e_sibling == ep) {
 373                                 np->e_sibling = ep->e_sibling;
 374                                 break;
 375                         }
 376                 }
 377                 if (np == NULL)
 378                         badentry(ep, "cannot find entry in parent list");
 379         }
 380 }
 381
 382 /*
 383  * Table of unused string entries, sorted by length.
 384  *
 385  * Entries are allocated in STRTBLINCR sized pieces so that names
 386  * of similar lengths can use the same entry. The value of STRTBLINCR
 387  * is chosen so that every entry has at least enough space to hold
 388  * a "struct strtbl" header. Thus every entry can be linked onto an
 389  * appropriate free list.
 390  *
 391  * NB. The macro "allocsize" below assumes that "struct strhdr"
 392  *     has a size that is a power of two.
 393  */
 394 struct strhdr {
 395         struct strhdr *next;
 396 };
 397
 398 #define STRTBLINCR      (sizeof(struct strhdr))
 399 #define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1))
 400
 401 static struct strhdr strtblhdr[allocsize(MAXNAMLEN) / STRTBLINCR];
 402
 403 /*
 404  * Allocate space for a name. It first looks to see if it already
 405  * has an appropriate sized entry, and if not allocates a new one.
 406  */
 407 char *
 408 savename(char *name)
 409 {
 410         struct strhdr *np;
 411         long len;
 412         char *cp;
 413
 414         if (name == NULL)
 415                 panic("bad name\n");
 416         len = strlen(name);
 417         np = strtblhdr[len / STRTBLINCR].next;
 418         if (np != NULL) {
 419                 strtblhdr[len / STRTBLINCR].next = np->next;
 420                 cp = (char *)np;
 421         } else {
 422                 cp = malloc((unsigned)allocsize(len));
 423                 if (cp == NULL)
 424                         errx(1, "no space for string table");
 425         }
 426         (void) strcpy(cp, name);
 427         return (cp);
 428 }
 429
 430 /*
 431  * Free space for a name. The resulting entry is linked onto the
 432  * appropriate free list.
 433  */
 434 void
 435 freename(char *name)
 436 {
 437         struct strhdr *tp, *np;
 438
 439         tp = &strtblhdr[strlen(name) / STRTBLINCR];
 440         np = (struct strhdr *)name;
 441         np->next = tp->next;
 442         tp->next = np;
 443 }
 444
 445 /*
 446  * Useful quantities placed at the end of a dumped symbol table.
 447  */
 448 struct symtableheader {
 449         int32_t volno;
 450         int32_t stringsize;
 451         int32_t entrytblsize;
 452         time_t  dumptime;
 453         time_t  dumpdate;
 454         dump_ino_t maxino;
 455         int32_t ntrec;
 456         int32_t zflag;
 457 };
 458
 459 /*
 460  * dump a snapshot of the symbol table
 461  */
 462 void
 463 dumpsymtable(char *filename, long checkpt)
 464 {
 465         struct entry *ep, *tep;
 466         dump_ino_t i;
 467         struct entry temp, *tentry;
 468         long mynum = 1, stroff = 0;
 469         FILE *fd;
 470         struct symtableheader hdr;
 471
 472         Vprintf(stdout, "Check pointing the restore\n");
 473         if (Nflag)
 474                 return;
 475         if ((fd = fopen(filename, "w")) == NULL) {
 476                 warn("fopen");
 477                 panic("cannot create save file %s for symbol table\n",
 478                         filename);
 479         }
 480         clearerr(fd);
 481         /*
 482          * Assign indices to each entry
 483          * Write out the string entries
 484          */
 485         for (i = WINO; i <= maxino; i++) {
 486                 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
 487                         ep->e_index = mynum++;
 488                         (void) fwrite(ep->e_name, sizeof(char),
 489                                (int)allocsize(ep->e_namlen), fd);
 490                 }
 491         }
 492         /*
 493          * Convert pointers to indexes, and output
 494          */
 495         tep = &temp;
 496         stroff = 0;
 497         for (i = WINO; i <= maxino; i++) {
 498                 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
 499                         memmove(tep, ep, sizeof(struct entry));
 500                         tep->e_name = (char *)stroff;
 501                         stroff += allocsize(ep->e_namlen);
 502                         tep->e_parent = (struct entry *)ep->e_parent->e_index;
 503                         if (ep->e_links != NULL)
 504                                 tep->e_links =
 505                                         (struct entry *)ep->e_links->e_index;
 506                         if (ep->e_sibling != NULL)
 507                                 tep->e_sibling =
 508                                         (struct entry *)ep->e_sibling->e_index;
 509                         if (ep->e_entries != NULL)
 510                                 tep->e_entries =
 511                                         (struct entry *)ep->e_entries->e_index;
 512                         if (ep->e_next != NULL)
 513                                 tep->e_next =
 514                                         (struct entry *)ep->e_next->e_index;
 515                         (void) fwrite((char *)tep, sizeof(struct entry), 1, fd);
 516                 }
 517         }
 518         /*
 519          * Convert entry pointers to indexes, and output
 520          */
 521         for (i = 0; (long)i < entrytblsize; i++) {
 522                 if (entry[i] == NULL)
 523                         tentry = NULL;
 524                 else
 525                         tentry = (struct entry *)entry[i]->e_index;
 526                 (void) fwrite((char *)&tentry, sizeof(struct entry *), 1, fd);
 527         }
 528         hdr.volno = checkpt;
 529         hdr.maxino = maxino;
 530         hdr.entrytblsize = entrytblsize;
 531         hdr.stringsize = stroff;
 532         hdr.dumptime = dumptime;
 533         hdr.dumpdate = dumpdate;
 534         hdr.ntrec = ntrec;
 535         hdr.zflag = zflag;
 536         (void) fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd);
 537         if (ferror(fd)) {
 538                 warn("fwrite");
 539                 panic("output error to file %s writing symbol table\n",
 540                         filename);
 541         }
 542         (void) fclose(fd);
 543 }
 544
 545 /*
 546  * Initialize a symbol table from a file
 547  */
 548 void
 549 initsymtable(char *filename)
 550 {
 551         char *base;
 552         long tblsize;
 553         struct entry *ep;
 554         struct entry *baseep, *lep;
 555         struct symtableheader hdr;
 556         struct stat stbuf;
 557         long i;
 558         int fd;
 559
 560         Vprintf(stdout, "Initialize symbol table.\n");
 561         if (filename == NULL) {
 562                 entrytblsize = maxino / HASHFACTOR;
 563                 entry = (struct entry **)
 564                         calloc((unsigned)entrytblsize, sizeof(struct entry *));
 565                 if (entry == (struct entry **)NULL)
 566                         errx(1, "no memory for entry table");
 567                 ep = addentry(".", ROOTINO, NODE);
 568                 ep->e_flags |= NEW;
 569                 return;
 570         }
 571         if ((fd = open(filename, O_RDONLY, 0)) < 0) {
 572                 warn("open");
 573                 errx(1, "cannot open symbol table file %s", filename);
 574         }
 575         if (fstat(fd, &stbuf) < 0) {
 576                 warn("stat");
 577                 errx(1, "cannot stat symbol table file %s", filename);
 578         }
 579         tblsize = stbuf.st_size - sizeof(struct symtableheader);
 580         base = calloc(sizeof(char), (unsigned)tblsize);
 581         if (base == NULL)
 582                 errx(1, "cannot allocate space for symbol table");
 583         if (read(fd, base, (int)tblsize) < 0 ||
 584             read(fd, (char *)&hdr, sizeof(struct symtableheader)) < 0) {
 585                 warn("read");
 586                 errx(1, "cannot read symbol table file %s", filename);
 587         }
 588         switch (command) {
 589         case 'r':
 590                 /*
 591                  * For normal continuation, insure that we are using
 592                  * the next incremental tape
 593                  */
 594                 if (hdr.dumpdate != dumptime)
 595                         errx(1, "Incremental tape too %s",
 596                                 (hdr.dumpdate < dumptime) ? "low" : "high");
 597                 break;
 598         case 'R':
 599                 /*
 600                  * For restart, insure that we are using the same tape
 601                  */
 602                 curfile.action = SKIP;
 603                 dumptime = hdr.dumptime;
 604                 dumpdate = hdr.dumpdate;
 605                 zflag = hdr.zflag;
 606                 if (!bflag)
 607                         newtapebuf(hdr.ntrec);
 608                 getvol(hdr.volno);
 609                 break;
 610         default:
 611                 panic("initsymtable called from command %c\n", command);
 612                 break;
 613         }
 614         resizemaps(maxino, hdr.maxino);
 615         maxino = hdr.maxino;
 616         entrytblsize = hdr.entrytblsize;
 617         entry = (struct entry **)
 618                 (base + tblsize - (entrytblsize * sizeof(struct entry *)));
 619         baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry));
 620         lep = (struct entry *)entry;
 621         for (i = 0; i < entrytblsize; i++) {
 622                 if (entry[i] == NULL)
 623                         continue;
 624                 entry[i] = &baseep[(long)entry[i]];
 625         }
 626         for (ep = &baseep[1]; ep < lep; ep++) {
 627                 ep->e_name = base + (long)ep->e_name;
 628                 ep->e_parent = &baseep[(long)ep->e_parent];
 629                 if (ep->e_sibling != NULL)
 630                         ep->e_sibling = &baseep[(long)ep->e_sibling];
 631                 if (ep->e_links != NULL)
 632                         ep->e_links = &baseep[(long)ep->e_links];
 633                 if (ep->e_entries != NULL)
 634                         ep->e_entries = &baseep[(long)ep->e_entries];
 635                 if (ep->e_next != NULL)
 636                         ep->e_next = &baseep[(long)ep->e_next];
 637         }
 638 }