sbin/restore/symtab.c

   1 /*
   2  * Copyright (c) 1983, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)symtab.c 8.3 (Berkeley) 4/28/95
  30  * $FreeBSD: src/sbin/restore/symtab.c,v 1.7.2.1 2001/12/19 14:54:14 tobez Exp $
  31  */
  32
  33 /*
  34  * These routines maintain the symbol table which tracks the state
  35  * of the file system being restored. They provide lookup by either
  36  * name or inode number. They also provide for creation, deletion,
  37  * and renaming of entries. Because of the dynamic nature of pathnames,
  38  * names should not be saved, but always constructed just before they
  39  * are needed, by calling "myname".
  40  */
  41
  42 #include <sys/param.h>
  43 #include <sys/stat.h>
  44
  45 #include <vfs/ufs/dinode.h>
  46
  47 #include <errno.h>
  48 #include <fcntl.h>
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52 #include <unistd.h>
  53
  54 #include "restore.h"
  55 #include "extern.h"
  56
  57 /*
  58  * The following variables define the inode symbol table.
  59  * The primary hash table is dynamically allocated based on
  60  * the number of inodes in the file system (maxino), scaled by
  61  * HASHFACTOR. The variable "entry" points to the hash table;
  62  * the variable "entrytblsize" indicates its size (in entries).
  63  */
  64 #define HASHFACTOR 5
  65 static struct entry **entry;
  66 static long entrytblsize;
  67
  68 static void              addino(ufs1_ino_t, struct entry *);
  69 static struct entry     *lookupparent(char *);
  70 static void              removeentry(struct entry *);
  71
  72 /*
  73  * Look up an entry by inode number
  74  */
  75 struct entry *
  76 lookupino(ufs1_ino_t inum)
  77 {
  78         struct entry *ep;
  79
  80         if (inum < WINO || inum >= maxino)
  81                 return (NULL);
  82         for (ep = entry[inum % entrytblsize]; ep != NULL; ep = ep->e_next)
  83                 if (ep->e_ino == inum)
  84                         return (ep);
  85         return (NULL);
  86 }
  87
  88 /*
  89  * Add an entry into the entry table
  90  */
  91 static void
  92 addino(ufs1_ino_t inum, struct entry *np)
  93 {
  94         struct entry **epp;
  95
  96         if (inum < WINO || inum >= maxino)
  97                 panic("addino: out of range %d\n", inum);
  98         epp = &entry[inum % entrytblsize];
  99         np->e_ino = inum;
 100         np->e_next = *epp;
 101         *epp = np;
 102         if (dflag)
 103                 for (np = np->e_next; np != NULL; np = np->e_next)
 104                         if (np->e_ino == inum)
 105                                 badentry(np, "duplicate inum");
 106 }
 107
 108 /*
 109  * Delete an entry from the entry table
 110  */
 111 void
 112 deleteino(ufs1_ino_t inum)
 113 {
 114         struct entry *next;
 115         struct entry **prev;
 116
 117         if (inum < WINO || inum >= maxino)
 118                 panic("deleteino: out of range %d\n", inum);
 119         prev = &entry[inum % entrytblsize];
 120         for (next = *prev; next != NULL; next = next->e_next) {
 121                 if (next->e_ino == inum) {
 122                         next->e_ino = 0;
 123                         *prev = next->e_next;
 124                         return;
 125                 }
 126                 prev = &next->e_next;
 127         }
 128         panic("deleteino: %d not found\n", inum);
 129 }
 130
 131 /*
 132  * Look up an entry by name
 133  */
 134 struct entry *
 135 lookupname(char *name)
 136 {
 137         struct entry *ep;
 138         char *np, *cp;
 139         char buf[MAXPATHLEN];
 140
 141         cp = name;
 142         for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) {
 143                 for (np = buf; *cp != '/' && *cp != '\0' &&
 144                                 np < &buf[sizeof(buf)]; )
 145                         *np++ = *cp++;
 146                 if (np == &buf[sizeof(buf)])
 147                         break;
 148                 *np = '\0';
 149                 for ( ; ep != NULL; ep = ep->e_sibling)
 150                         if (strcmp(ep->e_name, buf) == 0)
 151                                 break;
 152                 if (ep == NULL)
 153                         break;
 154                 if (*cp++ == '\0')
 155                         return (ep);
 156         }
 157         return (NULL);
 158 }
 159
 160 /*
 161  * Look up the parent of a pathname
 162  */
 163 static struct entry *
 164 lookupparent(char *name)
 165 {
 166         struct entry *ep;
 167         char *tailindex;
 168
 169         tailindex = strrchr(name, '/');
 170         if (tailindex == NULL)
 171                 return (NULL);
 172         *tailindex = '\0';
 173         ep = lookupname(name);
 174         *tailindex = '/';
 175         if (ep == NULL)
 176                 return (NULL);
 177         if (ep->e_type != NODE)
 178                 panic("%s is not a directory\n", name);
 179         return (ep);
 180 }
 181
 182 /*
 183  * Determine the current pathname of a node or leaf
 184  */
 185 char *
 186 myname(struct entry *ep)
 187 {
 188         char *cp;
 189         static char namebuf[MAXPATHLEN];
 190
 191         for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) {
 192                 cp -= ep->e_namlen;
 193                 memmove(cp, ep->e_name, (long)ep->e_namlen);
 194                 if (ep == lookupino(ROOTINO))
 195                         return (cp);
 196                 *(--cp) = '/';
 197                 ep = ep->e_parent;
 198         }
 199         panic("%s: pathname too long\n", cp);
 200         return(cp);
 201 }
 202
 203 /*
 204  * Unused symbol table entries are linked together on a free list
 205  * headed by the following pointer.
 206  */
 207 static struct entry *freelist = NULL;
 208
 209 /*
 210  * add an entry to the symbol table
 211  */
 212 struct entry *
 213 addentry(char *name, ufs1_ino_t inum, int type)
 214 {
 215         struct entry *np, *ep;
 216
 217         if (freelist != NULL) {
 218                 np = freelist;
 219                 freelist = np->e_next;
 220                 memset(np, 0, (long)sizeof(struct entry));
 221         } else {
 222                 np = (struct entry *)calloc(1, sizeof(struct entry));
 223                 if (np == NULL)
 224                         panic("no memory to extend symbol table\n");
 225         }
 226         np->e_type = type & ~LINK;
 227         ep = lookupparent(name);
 228         if (ep == NULL) {
 229                 if (inum != ROOTINO || lookupino(ROOTINO) != NULL)
 230                         panic("bad name to addentry %s\n", name);
 231                 np->e_name = savename(name);
 232                 np->e_namlen = strlen(name);
 233                 np->e_parent = np;
 234                 addino(ROOTINO, np);
 235                 return (np);
 236         }
 237         np->e_name = savename(strrchr(name, '/') + 1);
 238         np->e_namlen = strlen(np->e_name);
 239         np->e_parent = ep;
 240         np->e_sibling = ep->e_entries;
 241         ep->e_entries = np;
 242         if (type & LINK) {
 243                 ep = lookupino(inum);
 244                 if (ep == NULL)
 245                         panic("link to non-existent name\n");
 246                 np->e_ino = inum;
 247                 np->e_links = ep->e_links;
 248                 ep->e_links = np;
 249         } else if (inum != 0) {
 250                 if (lookupino(inum) != NULL)
 251                         panic("duplicate entry\n");
 252                 addino(inum, np);
 253         }
 254         return (np);
 255 }
 256
 257 /*
 258  * delete an entry from the symbol table
 259  */
 260 void
 261 freeentry(struct entry *ep)
 262 {
 263         struct entry *np;
 264         ufs1_ino_t inum;
 265
 266         if (ep->e_flags != REMOVED)
 267                 badentry(ep, "not marked REMOVED");
 268         if (ep->e_type == NODE) {
 269                 if (ep->e_links != NULL)
 270                         badentry(ep, "freeing referenced directory");
 271                 if (ep->e_entries != NULL)
 272                         badentry(ep, "freeing non-empty directory");
 273         }
 274         if (ep->e_ino != 0) {
 275                 np = lookupino(ep->e_ino);
 276                 if (np == NULL)
 277                         badentry(ep, "lookupino failed");
 278                 if (np == ep) {
 279                         inum = ep->e_ino;
 280                         deleteino(inum);
 281                         if (ep->e_links != NULL)
 282                                 addino(inum, ep->e_links);
 283                 } else {
 284                         for (; np != NULL; np = np->e_links) {
 285                                 if (np->e_links == ep) {
 286                                         np->e_links = ep->e_links;
 287                                         break;
 288                                 }
 289                         }
 290                         if (np == NULL)
 291                                 badentry(ep, "link not found");
 292                 }
 293         }
 294         removeentry(ep);
 295         freename(ep->e_name);
 296         ep->e_next = freelist;
 297         freelist = ep;
 298 }
 299
 300 /*
 301  * Relocate an entry in the tree structure
 302  */
 303 void
 304 moveentry(struct entry *ep, char *newname)
 305 {
 306         struct entry *np;
 307         char *cp;
 308
 309         np = lookupparent(newname);
 310         if (np == NULL)
 311                 badentry(ep, "cannot move ROOT");
 312         if (np != ep->e_parent) {
 313                 removeentry(ep);
 314                 ep->e_parent = np;
 315                 ep->e_sibling = np->e_entries;
 316                 np->e_entries = ep;
 317         }
 318         cp = strrchr(newname, '/') + 1;
 319         freename(ep->e_name);
 320         ep->e_name = savename(cp);
 321         ep->e_namlen = strlen(cp);
 322         if (strcmp(gentempname(ep), ep->e_name) == 0)
 323                 ep->e_flags |= TMPNAME;
 324         else
 325                 ep->e_flags &= ~TMPNAME;
 326 }
 327
 328 /*
 329  * Remove an entry in the tree structure
 330  */
 331 static void
 332 removeentry(struct entry *ep)
 333 {
 334         struct entry *np;
 335
 336         np = ep->e_parent;
 337         if (np->e_entries == ep) {
 338                 np->e_entries = ep->e_sibling;
 339         } else {
 340                 for (np = np->e_entries; np != NULL; np = np->e_sibling) {
 341                         if (np->e_sibling == ep) {
 342                                 np->e_sibling = ep->e_sibling;
 343                                 break;
 344                         }
 345                 }
 346                 if (np == NULL)
 347                         badentry(ep, "cannot find entry in parent list");
 348         }
 349 }
 350
 351 /*
 352  * Table of unused string entries, sorted by length.
 353  *
 354  * Entries are allocated in STRTBLINCR sized pieces so that names
 355  * of similar lengths can use the same entry. The value of STRTBLINCR
 356  * is chosen so that every entry has at least enough space to hold
 357  * a "struct strtbl" header. Thus every entry can be linked onto an
 358  * appropriate free list.
 359  *
 360  * NB. The macro "allocsize" below assumes that "struct strhdr"
 361  *     has a size that is a power of two.
 362  */
 363 struct strhdr {
 364         struct strhdr *next;
 365 };
 366
 367 #define STRTBLINCR      (sizeof(struct strhdr))
 368 #define allocsize(size) roundup2((size) + 1, STRTBLINCR)
 369
 370 static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR];
 371
 372 /*
 373  * Allocate space for a name. It first looks to see if it already
 374  * has an appropriate sized entry, and if not allocates a new one.
 375  */
 376 char *
 377 savename(char *name)
 378 {
 379         struct strhdr *np;
 380         long len;
 381         char *cp;
 382
 383         if (name == NULL)
 384                 panic("bad name\n");
 385         len = strlen(name);
 386         np = strtblhdr[len / STRTBLINCR].next;
 387         if (np != NULL) {
 388                 strtblhdr[len / STRTBLINCR].next = np->next;
 389                 cp = (char *)np;
 390         } else {
 391                 cp = malloc((unsigned)allocsize(len));
 392                 if (cp == NULL)
 393                         panic("no space for string table\n");
 394         }
 395         strcpy(cp, name);
 396         return (cp);
 397 }
 398
 399 /*
 400  * Free space for a name. The resulting entry is linked onto the
 401  * appropriate free list.
 402  */
 403 void
 404 freename(char *name)
 405 {
 406         struct strhdr *tp, *np;
 407
 408         tp = &strtblhdr[strlen(name) / STRTBLINCR];
 409         np = (struct strhdr *)name;
 410         np->next = tp->next;
 411         tp->next = np;
 412 }
 413
 414 /*
 415  * Useful quantities placed at the end of a dumped symbol table.
 416  */
 417 struct symtableheader {
 418         int32_t volno;
 419         int32_t stringsize;
 420         int32_t entrytblsize;
 421         time_t  dumptime;
 422         time_t  dumpdate;
 423         ufs1_ino_t maxino;
 424         int32_t ntrec;
 425 };
 426
 427 /*
 428  * dump a snapshot of the symbol table
 429  */
 430 void
 431 dumpsymtable(char *filename, long checkpt)
 432 {
 433         struct entry *ep, *tep;
 434         ufs1_ino_t i;
 435         struct entry temp, *tentry;
 436         long mynum = 1, stroff = 0;
 437         FILE *fd;
 438         struct symtableheader hdr;
 439
 440         vprintf(stdout, "Check pointing the restore\n");
 441         if (Nflag)
 442                 return;
 443         if ((fd = fopen(filename, "w")) == NULL) {
 444                 fprintf(stderr, "fopen: %s\n", strerror(errno));
 445                 panic("cannot create save file %s for symbol table\n",
 446                         filename);
 447                 done(1);
 448         }
 449         clearerr(fd);
 450         /*
 451          * Assign indices to each entry
 452          * Write out the string entries
 453          */
 454         for (i = WINO; i <= maxino; i++) {
 455                 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
 456                         ep->e_index = mynum++;
 457                         fwrite(ep->e_name, sizeof(char),
 458                                (int)allocsize(ep->e_namlen), fd);
 459                 }
 460         }
 461         /*
 462          * Convert pointers to indexes, and output
 463          */
 464         tep = &temp;
 465         stroff = 0;
 466         for (i = WINO; i <= maxino; i++) {
 467                 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
 468                         memmove(tep, ep, (long)sizeof(struct entry));
 469                         tep->e_name = (char *)stroff;
 470                         stroff += allocsize(ep->e_namlen);
 471                         tep->e_parent = (struct entry *)ep->e_parent->e_index;
 472                         if (ep->e_links != NULL)
 473                                 tep->e_links =
 474                                         (struct entry *)ep->e_links->e_index;
 475                         if (ep->e_sibling != NULL)
 476                                 tep->e_sibling =
 477                                         (struct entry *)ep->e_sibling->e_index;
 478                         if (ep->e_entries != NULL)
 479                                 tep->e_entries =
 480                                         (struct entry *)ep->e_entries->e_index;
 481                         if (ep->e_next != NULL)
 482                                 tep->e_next =
 483                                         (struct entry *)ep->e_next->e_index;
 484                         fwrite((char *)tep, sizeof(struct entry), 1, fd);
 485                 }
 486         }
 487         /*
 488          * Convert entry pointers to indexes, and output
 489          */
 490         for (i = 0; i < entrytblsize; i++) {
 491                 if (entry[i] == NULL)
 492                         tentry = NULL;
 493                 else
 494                         tentry = (struct entry *)entry[i]->e_index;
 495                 fwrite((char *)&tentry, sizeof(struct entry *), 1, fd);
 496         }
 497         hdr.volno = checkpt;
 498         hdr.maxino = maxino;
 499         hdr.entrytblsize = entrytblsize;
 500         hdr.stringsize = stroff;
 501         hdr.dumptime = dumptime;
 502         hdr.dumpdate = dumpdate;
 503         hdr.ntrec = ntrec;
 504         fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd);
 505         if (ferror(fd)) {
 506                 fprintf(stderr, "fwrite: %s\n", strerror(errno));
 507                 panic("output error to file %s writing symbol table\n",
 508                         filename);
 509         }
 510         fclose(fd);
 511 }
 512
 513 /*
 514  * Initialize a symbol table from a file
 515  */
 516 void
 517 initsymtable(char *filename)
 518 {
 519         char *base;
 520         long tblsize;
 521         struct entry *ep;
 522         struct entry *baseep, *lep;
 523         struct symtableheader hdr;
 524         struct stat stbuf;
 525         long i;
 526         int fd;
 527
 528         vprintf(stdout, "Initialize symbol table.\n");
 529         if (filename == NULL) {
 530                 entrytblsize = maxino / HASHFACTOR;
 531                 entry = (struct entry **)
 532                         calloc((unsigned)entrytblsize, sizeof(struct entry *));
 533                 if (entry == NULL)
 534                         panic("no memory for entry table\n");
 535                 ep = addentry(".", ROOTINO, NODE);
 536                 ep->e_flags |= NEW;
 537                 return;
 538         }
 539         if ((fd = open(filename, O_RDONLY, 0)) < 0) {
 540                 fprintf(stderr, "open: %s\n", strerror(errno));
 541                 panic("cannot open symbol table file %s\n", filename);
 542         }
 543         if (fstat(fd, &stbuf) < 0) {
 544                 fprintf(stderr, "stat: %s\n", strerror(errno));
 545                 panic("cannot stat symbol table file %s\n", filename);
 546         }
 547         tblsize = stbuf.st_size - sizeof(struct symtableheader);
 548         base = calloc(sizeof(char), (unsigned)tblsize);
 549         if (base == NULL)
 550                 panic("cannot allocate space for symbol table\n");
 551         if (read(fd, base, (int)tblsize) < 0 ||
 552             read(fd, (char *)&hdr, sizeof(struct symtableheader)) < 0) {
 553                 fprintf(stderr, "read: %s\n", strerror(errno));
 554                 panic("cannot read symbol table file %s\n", filename);
 555         }
 556         switch (command) {
 557         case 'r':
 558                 /*
 559                  * For normal continuation, insure that we are using
 560                  * the next incremental tape
 561                  */
 562                 if (hdr.dumpdate != dumptime) {
 563                         if (hdr.dumpdate < dumptime)
 564                                 fprintf(stderr, "Incremental tape too low\n");
 565                         else
 566                                 fprintf(stderr, "Incremental tape too high\n");
 567                         done(1);
 568                 }
 569                 break;
 570         case 'R':
 571                 /*
 572                  * For restart, insure that we are using the same tape
 573                  */
 574                 curfile.action = SKIP;
 575                 dumptime = hdr.dumptime;
 576                 dumpdate = hdr.dumpdate;
 577                 if (!bflag)
 578                         newtapebuf(hdr.ntrec);
 579                 getvol(hdr.volno);
 580                 break;
 581         default:
 582                 panic("initsymtable called from command %c\n", command);
 583                 break;
 584         }
 585         maxino = hdr.maxino;
 586         entrytblsize = hdr.entrytblsize;
 587         entry = (struct entry **)
 588                 (base + tblsize - (entrytblsize * sizeof(struct entry *)));
 589         baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry));
 590         lep = (struct entry *)entry;
 591         for (i = 0; i < entrytblsize; i++) {
 592                 if (entry[i] == NULL)
 593                         continue;
 594                 entry[i] = &baseep[(long)entry[i]];
 595         }
 596         for (ep = &baseep[1]; ep < lep; ep++) {
 597                 ep->e_name = base + (long)ep->e_name;
 598                 ep->e_parent = &baseep[(long)ep->e_parent];
 599                 if (ep->e_sibling != NULL)
 600                         ep->e_sibling = &baseep[(long)ep->e_sibling];
 601                 if (ep->e_links != NULL)
 602                         ep->e_links = &baseep[(long)ep->e_links];
 603                 if (ep->e_entries != NULL)
 604                         ep->e_entries = &baseep[(long)ep->e_entries];
 605                 if (ep->e_next != NULL)
 606                         ep->e_next = &baseep[(long)ep->e_next];
 607         }
 608 }