sbin/restore/symtab.c

   1 /*      $NetBSD: symtab.c,v 1.24 2009/02/22 15:28:43 yamt Exp $ */
   2
   3 /*
   4  * Copyright (c) 1983, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   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  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "@(#)symtab.c    8.3 (Berkeley) 4/28/95";
  36 #else
  37 __RCSID("$NetBSD: symtab.c,v 1.24 2009/02/22 15:28:43 yamt Exp $");
  38 #endif
  39 #endif /* not lint */
  40
  41 /*
  42  * These routines maintain the symbol table which tracks the state
  43  * of the file system being restored. They provide lookup by either
  44  * name or inode number. They also provide for creation, deletion,
  45  * and renaming of entries. Because of the dynamic nature of pathnames,
  46  * names should not be saved, but always constructed just before they
  47  * are needed, by calling "myname".
  48  */
  49
  50 #include <sys/param.h>
  51 #include <sys/stat.h>
  52
  53 #include <ufs/ufs/dinode.h>
  54
  55 #include <errno.h>
  56 #include <fcntl.h>
  57 #include <stdio.h>
  58 #include <stdlib.h>
  59 #include <string.h>
  60 #include <unistd.h>
  61
  62 #include "restore.h"
  63 #include "extern.h"
  64
  65 /*
  66  * The following variables define the inode symbol table.
  67  * The primary hash table is dynamically allocated based on
  68  * the number of inodes in the file system (maxino), scaled by
  69  * HASHFACTOR. The variable "entry" points to the hash table;
  70  * the variable "entrytblsize" indicates its size (in entries).
  71  */
  72 #define HASHFACTOR 5
  73 static struct entry **entry;
  74 static long entrytblsize;
  75
  76 static void              addino(ino_t, struct entry *);
  77 static struct entry     *lookupparent(const char *);
  78 static void              removeentry(struct entry *);
  79
  80 /*
  81  * Look up an entry by inode number
  82  */
  83 struct entry *
  84 lookupino(ino_t inum)
  85 {
  86         struct entry *ep;
  87
  88         if (inum < WINO || inum >= maxino)
  89                 return (NULL);
  90         for (ep = entry[inum % entrytblsize]; ep != NULL; ep = ep->e_next)
  91                 if (ep->e_ino == inum)
  92                         return (ep);
  93         return (NULL);
  94 }
  95
  96 /*
  97  * Add an entry into the entry table
  98  */
  99 static void
 100 addino(ino_t inum, struct entry *np)
 101 {
 102         struct entry **epp;
 103
 104         if (inum < WINO || inum >= maxino)
 105                 panic("addino: out of range %llu\n", (unsigned long long)inum);
 106         epp = &entry[inum % entrytblsize];
 107         np->e_ino = inum;
 108         np->e_next = *epp;
 109         *epp = np;
 110         if (dflag)
 111                 for (np = np->e_next; np != NULL; np = np->e_next)
 112                         if (np->e_ino == inum)
 113                                 badentry(np, "duplicate inum");
 114 }
 115
 116 /*
 117  * Delete an entry from the entry table
 118  */
 119 void
 120 deleteino(ino_t inum)
 121 {
 122         struct entry *next;
 123         struct entry **prev;
 124
 125         if (inum < WINO || inum >= maxino)
 126                 panic("deleteino: out of range %llu\n",
 127                     (unsigned long long)inum);
 128         prev = &entry[inum % entrytblsize];
 129         for (next = *prev; next != NULL; next = next->e_next) {
 130                 if (next->e_ino == inum) {
 131                         next->e_ino = 0;
 132                         *prev = next->e_next;
 133                         return;
 134                 }
 135                 prev = &next->e_next;
 136         }
 137         panic("deleteino: %llu not found\n", (unsigned long long)inum);
 138 }
 139
 140 /*
 141  * Look up an entry by name
 142  */
 143 struct entry *
 144 lookupname(const char *name)
 145 {
 146         struct entry *ep;
 147         char *np;
 148         const char *cp;
 149         char buf[MAXPATHLEN];
 150
 151         cp = name;
 152         for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) {
 153                 for (np = buf; *cp != '/' && *cp != '\0'; )
 154                         *np++ = *cp++;
 155                 *np = '\0';
 156                 for ( ; ep != NULL; ep = ep->e_sibling)
 157                         if (strcmp(ep->e_name, buf) == 0)
 158                                 break;
 159                 if (ep == NULL)
 160                         break;
 161                 if (*cp++ == '\0')
 162                         return (ep);
 163         }
 164         return (NULL);
 165 }
 166
 167 /*
 168  * Look up the parent of a pathname
 169  */
 170 static struct entry *
 171 lookupparent(const char *name)
 172 {
 173         struct entry *ep;
 174         char *tailindex;
 175
 176         tailindex = strrchr(name, '/');
 177         if (tailindex == NULL)
 178                 return (NULL);
 179         *tailindex = '\0';
 180         ep = lookupname(name);
 181         *tailindex = '/';
 182         if (ep == NULL)
 183                 return (NULL);
 184         if (ep->e_type != NODE)
 185                 panic("%s is not a directory\n", name);
 186         return (ep);
 187 }
 188
 189 /*
 190  * Determine the current pathname of a node or leaf
 191  */
 192 char *
 193 myname(struct entry *ep)
 194 {
 195         char *cp;
 196         static char namebuf[MAXPATHLEN];
 197
 198         for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) {
 199                 cp -= ep->e_namlen;
 200                 memmove(cp, ep->e_name, (long)ep->e_namlen);
 201                 if (ep == lookupino(ROOTINO))
 202                         return (cp);
 203                 *(--cp) = '/';
 204                 ep = ep->e_parent;
 205         }
 206         panic("%s: pathname too long\n", cp);
 207         return(cp);
 208 }
 209
 210 /*
 211  * Unused symbol table entries are linked together on a freelist
 212  * headed by the following pointer.
 213  */
 214 static struct entry *freelist = NULL;
 215
 216 /*
 217  * add an entry to the symbol table
 218  */
 219 struct entry *
 220 addentry(const char *name, ino_t inum, int type)
 221 {
 222         struct entry *np, *ep;
 223
 224         if (freelist == NULL) {
 225                 np = malloc(pagesize);
 226                 if (np == NULL)
 227                         panic("no memory to extend symbol table\n");
 228                 for (ep = (struct entry *)((char *)np + pagesize) - 1;
 229                     np <= ep; np++) {
 230                         np->e_next = freelist;
 231                         freelist = np;
 232                 }
 233         }
 234         np = freelist;
 235         freelist = np->e_next;
 236         memset(np, 0, sizeof(struct entry));
 237
 238         np->e_type = type & ~LINK;
 239         ep = lookupparent(name);
 240         if (ep == NULL) {
 241                 if (inum != ROOTINO || lookupino(ROOTINO) != NULL)
 242                         panic("bad name to addentry %s\n", name);
 243                 np->e_name = savename(name);
 244                 np->e_namlen = strlen(name);
 245                 np->e_parent = np;
 246                 addino(ROOTINO, np);
 247                 return (np);
 248         }
 249         np->e_name = savename(strrchr(name, '/') + 1);
 250         np->e_namlen = strlen(np->e_name);
 251         np->e_parent = ep;
 252         np->e_sibling = ep->e_entries;
 253         ep->e_entries = np;
 254         if (type & LINK) {
 255                 ep = lookupino(inum);
 256                 if (ep == NULL)
 257                         panic("link to non-existent name\n");
 258                 np->e_ino = inum;
 259                 np->e_links = ep->e_links;
 260                 ep->e_links = np;
 261         } else if (inum != 0) {
 262                 if (lookupino(inum) != NULL)
 263                         panic("duplicate entry\n");
 264                 addino(inum, np);
 265         }
 266         return (np);
 267 }
 268
 269 /*
 270  * delete an entry from the symbol table
 271  */
 272 void
 273 freeentry(struct entry *ep)
 274 {
 275         struct entry *np;
 276         ino_t inum;
 277
 278         if (ep->e_flags != REMOVED)
 279                 badentry(ep, "not marked REMOVED");
 280         if (ep->e_type == NODE) {
 281                 if (ep->e_links != NULL)
 282                         badentry(ep, "freeing referenced directory");
 283                 if (ep->e_entries != NULL)
 284                         badentry(ep, "freeing non-empty directory");
 285         }
 286         if (ep->e_ino != 0) {
 287                 np = lookupino(ep->e_ino);
 288                 if (np == NULL)
 289                         badentry(ep, "lookupino failed");
 290                 if (np == ep) {
 291                         inum = ep->e_ino;
 292                         deleteino(inum);
 293                         if (ep->e_links != NULL)
 294                                 addino(inum, ep->e_links);
 295                 } else {
 296                         for (; np != NULL; np = np->e_links) {
 297                                 if (np->e_links == ep) {
 298                                         np->e_links = ep->e_links;
 299                                         break;
 300                                 }
 301                         }
 302                         if (np == NULL)
 303                                 badentry(ep, "link not found");
 304                 }
 305         }
 306         removeentry(ep);
 307         freename(ep->e_name);
 308         ep->e_next = freelist;
 309         freelist = ep;
 310 }
 311
 312 /*
 313  * Relocate an entry in the tree structure
 314  */
 315 void
 316 moveentry(struct entry *ep, const char *newname)
 317 {
 318         struct entry *np;
 319         char *cp;
 320
 321         np = lookupparent(newname);
 322         if (np == NULL)
 323                 badentry(ep, "cannot move ROOT");
 324         if (np != ep->e_parent) {
 325                 removeentry(ep);
 326                 ep->e_parent = np;
 327                 ep->e_sibling = np->e_entries;
 328                 np->e_entries = ep;
 329         }
 330         cp = strrchr(newname, '/') + 1;
 331         freename(ep->e_name);
 332         ep->e_name = savename(cp);
 333         ep->e_namlen = strlen(cp);
 334         if (strcmp(gentempname(ep), ep->e_name) == 0)
 335                 ep->e_flags |= TMPNAME;
 336         else
 337                 ep->e_flags &= ~TMPNAME;
 338 }
 339
 340 /*
 341  * Remove an entry in the tree structure
 342  */
 343 static void
 344 removeentry(struct entry *ep)
 345 {
 346         struct entry *np;
 347
 348         np = ep->e_parent;
 349         if (np->e_entries == ep) {
 350                 np->e_entries = ep->e_sibling;
 351         } else {
 352                 for (np = np->e_entries; np != NULL; np = np->e_sibling) {
 353                         if (np->e_sibling == ep) {
 354                                 np->e_sibling = ep->e_sibling;
 355                                 break;
 356                         }
 357                 }
 358                 if (np == NULL)
 359                         badentry(ep, "cannot find entry in parent list");
 360         }
 361 }
 362
 363 /*
 364  * Table of unused string entries, sorted by length.
 365  *
 366  * Entries are allocated in STRTBLINCR sized pieces so that names
 367  * of similar lengths can use the same entry. The value of STRTBLINCR
 368  * is chosen so that every entry has at least enough space to hold
 369  * a "struct strtbl" header. Thus every entry can be linked onto an
 370  * appropriate free list.
 371  *
 372  * NB. The macro "allocsize" below assumes that "struct strhdr"
 373  *     has a size that is a power of two.
 374  */
 375 struct strhdr {
 376         struct strhdr *next;
 377 };
 378
 379 #define STRTBLINCR      (sizeof(struct strhdr))
 380 #define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1))
 381
 382 static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR];
 383
 384 /*
 385  * Allocate space for a name. It first looks to see if it already
 386  * has an appropriate sized entry, and if not allocates a new one.
 387  */
 388 char *
 389 savename(const char *name)
 390 {
 391         struct strhdr *np, *tp;
 392         long len, siz;
 393         char *cp, *ep;
 394
 395         if (name == NULL)
 396                 panic("bad name\n");
 397         len = strlen(name);
 398         tp = &strtblhdr[len / STRTBLINCR];
 399         if (tp->next == NULL) {
 400                 cp = malloc(pagesize);
 401                 if (cp == NULL)
 402                         panic("no space for string table\n");
 403                 for (siz = allocsize(len), ep = (cp + pagesize) - siz;
 404                     cp <= ep; cp += siz) {
 405                         np = (struct strhdr *)cp;
 406                         np->next = tp->next;
 407                         tp->next = np;
 408                 }
 409         }
 410         np = tp->next;
 411         tp->next = np->next;
 412         cp = (char *)np;
 413         (void) strcpy(cp, name);
 414         return (cp);
 415 }
 416
 417 /*
 418  * Free space for a name. The resulting entry is linked onto the
 419  * appropriate free list.
 420  */
 421 void
 422 freename(char *name)
 423 {
 424         struct strhdr *tp, *np;
 425
 426         tp = &strtblhdr[strlen(name) / STRTBLINCR];
 427         np = (struct strhdr *)name;
 428         np->next = tp->next;
 429         tp->next = np;
 430 }
 431
 432 /*
 433  * Useful quantities placed at the end of a dumped symbol table.
 434  */
 435 struct symtableheader {
 436         int32_t volno;
 437         int32_t stringsize;
 438         int32_t entrytblsize;
 439         time_t  dumptime;
 440         time_t  dumpdate;
 441         ino_t   maxino;
 442         int32_t ntrec;
 443 };
 444
 445 /*
 446  * dump a snapshot of the symbol table
 447  */
 448 void
 449 dumpsymtable(const char *filename, int32_t checkpt)
 450 {
 451         struct entry *ep, *tep;
 452         ino_t i;
 453         long l;
 454         struct entry temp, *tentry;
 455         long mynum = 1, stroff = 0;
 456         FILE *fd;
 457         struct symtableheader hdr;
 458
 459         vprintf(stdout, "Check pointing the restore\n");
 460         if (Nflag)
 461                 return;
 462         if ((fd = fopen(filename, "w")) == NULL) {
 463                 fprintf(stderr, "fopen: %s\n", strerror(errno));
 464                 panic("cannot create save file %s for symbol table\n",
 465                         filename);
 466         }
 467         clearerr(fd);
 468         /*
 469          * Assign indicies to each entry
 470          * Write out the string entries
 471          */
 472         for (i = WINO; i <= maxino; i++) {
 473                 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
 474                         ep->e_index = mynum++;
 475                         (void) fwrite(ep->e_name, sizeof(char),
 476                                (int)allocsize(ep->e_namlen), fd);
 477                 }
 478         }
 479         /*
 480          * Convert pointers to indexes, and output
 481          */
 482         tep = &temp;
 483         stroff = 0;
 484         for (i = WINO; i <= maxino; i++) {
 485                 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
 486                         memmove(tep, ep, (long)sizeof(struct entry));
 487                         tep->e_name = (char *)stroff;
 488                         stroff += allocsize(ep->e_namlen);
 489                         tep->e_parent = (struct entry *)(long)
 490                             ep->e_parent->e_index;
 491                         if (ep->e_links != NULL)
 492                                 tep->e_links = (struct entry *)(long)
 493                                     ep->e_links->e_index;
 494                         if (ep->e_sibling != NULL)
 495                                 tep->e_sibling = (struct entry *)(long)
 496                                     ep->e_sibling->e_index;
 497                         if (ep->e_entries != NULL)
 498                                 tep->e_entries = (struct entry *)(long)
 499                                     ep->e_entries->e_index;
 500                         if (ep->e_next != NULL)
 501                                 tep->e_next = (struct entry *)(long)
 502                                     ep->e_next->e_index;
 503                         (void) fwrite((char *)tep, sizeof(struct entry), 1, fd);
 504                 }
 505         }
 506         /*
 507          * Convert entry pointers to indexes, and output
 508          */
 509         for (l = 0; l < entrytblsize; l++) {
 510                 if (entry[l] == NULL)
 511                         tentry = NULL;
 512                 else
 513                         tentry = (struct entry *)(long)entry[l]->e_index;
 514                 (void) fwrite((char *)&tentry, sizeof(struct entry *), 1, fd);
 515         }
 516         hdr.volno = checkpt;
 517         hdr.maxino = maxino;
 518         hdr.entrytblsize = entrytblsize;
 519         hdr.stringsize = stroff;
 520         hdr.dumptime = dumptime;
 521         hdr.dumpdate = dumpdate;
 522         hdr.ntrec = ntrec;
 523         (void) fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd);
 524         if (ferror(fd)) {
 525                 fprintf(stderr, "fwrite: %s\n", strerror(errno));
 526                 panic("output error to file %s writing symbol table\n",
 527                         filename);
 528         }
 529         (void) fclose(fd);
 530 }
 531
 532 /*
 533  * Initialize a symbol table from a file
 534  */
 535 void
 536 initsymtable(const char *filename)
 537 {
 538         char *base;
 539         long tblsize;
 540         struct entry *ep;
 541         struct entry *baseep, *lep;
 542         struct symtableheader hdr;
 543         struct stat stbuf;
 544         long i;
 545         int fd;
 546
 547         vprintf(stdout, "Initialize symbol table.\n");
 548         if (filename == NULL) {
 549                 entrytblsize = maxino / HASHFACTOR;
 550                 entry = (struct entry **)
 551                         calloc((unsigned)entrytblsize, sizeof(struct entry *));
 552                 if (entry == (struct entry **)NULL)
 553                         panic("no memory for entry table\n");
 554                 ep = addentry(".", ROOTINO, NODE);
 555                 ep->e_flags |= NEW;
 556                 return;
 557         }
 558         if ((fd = open(filename, O_RDONLY, 0)) < 0) {
 559                 fprintf(stderr, "open: %s\n", strerror(errno));
 560                 panic("cannot open symbol table file %s\n", filename);
 561         }
 562         if (fstat(fd, &stbuf) < 0) {
 563                 fprintf(stderr, "stat: %s\n", strerror(errno));
 564                 panic("cannot stat symbol table file %s\n", filename);
 565         }
 566         tblsize = stbuf.st_size - sizeof(struct symtableheader);
 567         base = calloc((unsigned)tblsize, sizeof(char));
 568         if (base == NULL)
 569                 panic("cannot allocate space for symbol table\n");
 570         if (read(fd, base, (int)tblsize) < 0 ||
 571             read(fd, (char *)&hdr, sizeof(struct symtableheader)) < 0) {
 572                 fprintf(stderr, "read: %s\n", strerror(errno));
 573                 panic("cannot read symbol table file %s\n", filename);
 574         }
 575         switch (command) {
 576         case 'r':
 577                 /*
 578                  * For normal continuation, insure that we are using
 579                  * the next incremental tape
 580                  */
 581                 if (hdr.dumpdate != dumptime) {
 582                         if (hdr.dumpdate < dumptime)
 583                                 fprintf(stderr, "Incremental tape too low\n");
 584                         else
 585                                 fprintf(stderr, "Incremental tape too high\n");
 586                         exit(1);
 587                 }
 588                 break;
 589         case 'R':
 590                 /*
 591                  * For restart, insure that we are using the same tape
 592                  */
 593                 curfile.action = SKIP;
 594                 dumptime = hdr.dumptime;
 595                 dumpdate = hdr.dumpdate;
 596                 if (!bflag)
 597                         newtapebuf(hdr.ntrec);
 598                 getvol(hdr.volno);
 599                 break;
 600         default:
 601                 panic("initsymtable called from command %c\n", command);
 602                 break;
 603         }
 604         maxino = hdr.maxino;
 605         entrytblsize = hdr.entrytblsize;
 606         entry = (struct entry **)
 607                 (base + tblsize - (entrytblsize * sizeof(struct entry *)));
 608         baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry));
 609         lep = (struct entry *)entry;
 610         for (i = 0; i < entrytblsize; i++) {
 611                 if (entry[i] == NULL)
 612                         continue;
 613                 entry[i] = &baseep[(long)entry[i]];
 614         }
 615         for (ep = &baseep[1]; ep < lep; ep++) {
 616                 ep->e_name = base + (long)ep->e_name;
 617                 ep->e_parent = &baseep[(long)ep->e_parent];
 618                 if (ep->e_sibling != NULL)
 619                         ep->e_sibling = &baseep[(long)ep->e_sibling];
 620                 if (ep->e_links != NULL)
 621                         ep->e_links = &baseep[(long)ep->e_links];
 622                 if (ep->e_entries != NULL)
 623                         ep->e_entries = &baseep[(long)ep->e_entries];
 624                 if (ep->e_next != NULL)
 625                         ep->e_next = &baseep[(long)ep->e_next];
 626         }
 627 }