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(const 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(const char *name)
 136 {
 137         struct entry *ep;
 138         const char *cp;
 139         char *np;
 140         char buf[MAXPATHLEN];
 141
 142         cp = name;
 143         for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) {
 144                 for (np = buf; *cp != '/' && *cp != '\0' &&
 145                                 np < &buf[sizeof(buf)]; )
 146                         *np++ = *cp++;
 147                 if (np == &buf[sizeof(buf)])
 148                         break;
 149                 *np = '\0';
 150                 for ( ; ep != NULL; ep = ep->e_sibling)
 151                         if (strcmp(ep->e_name, buf) == 0)
 152                                 break;
 153                 if (ep == NULL)
 154                         break;
 155                 if (*cp++ == '\0')
 156                         return (ep);
 157         }
 158         return (NULL);
 159 }
 160
 161 /*
 162  * Look up the parent of a pathname
 163  */
 164 static struct entry *
 165 lookupparent(const char *name)
 166 {
 167         struct entry *ep;
 168         char *tailindex;
 169
 170         tailindex = strrchr(name, '/');
 171         if (tailindex == NULL)
 172                 return (NULL);
 173         *tailindex = '\0';
 174         ep = lookupname(name);
 175         *tailindex = '/';
 176         if (ep == NULL)
 177                 return (NULL);
 178         if (ep->e_type != NODE)
 179                 panic("%s is not a directory\n", name);
 180         return (ep);
 181 }
 182
 183 /*
 184  * Determine the current pathname of a node or leaf
 185  */
 186 char *
 187 myname(struct entry *ep)
 188 {
 189         char *cp;
 190         static char namebuf[MAXPATHLEN];
 191
 192         for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) {
 193                 cp -= ep->e_namlen;
 194                 memmove(cp, ep->e_name, (long)ep->e_namlen);
 195                 if (ep == lookupino(ROOTINO))
 196                         return (cp);
 197                 *(--cp) = '/';
 198                 ep = ep->e_parent;
 199         }
 200         panic("%s: pathname too long\n", cp);
 201         return(cp);
 202 }
 203
 204 /*
 205  * Unused symbol table entries are linked together on a free list
 206  * headed by the following pointer.
 207  */
 208 static struct entry *freelist = NULL;
 209
 210 /*
 211  * add an entry to the symbol table
 212  */
 213 struct entry *
 214 addentry(const char *name, ufs1_ino_t inum, int type)
 215 {
 216         struct entry *np, *ep;
 217
 218         if (freelist != NULL) {
 219                 np = freelist;
 220                 freelist = np->e_next;
 221                 memset(np, 0, (long)sizeof(struct entry));
 222         } else {
 223                 np = (struct entry *)calloc(1, sizeof(struct entry));
 224                 if (np == NULL)
 225                         panic("no memory to extend symbol table\n");
 226         }
 227         np->e_type = type & ~LINK;
 228         ep = lookupparent(name);
 229         if (ep == NULL) {
 230                 if (inum != ROOTINO || lookupino(ROOTINO) != NULL)
 231                         panic("bad name to addentry %s\n", name);
 232                 np->e_name = savename(name);
 233                 np->e_namlen = strlen(name);
 234                 np->e_parent = np;
 235                 addino(ROOTINO, np);
 236                 return (np);
 237         }
 238         np->e_name = savename(strrchr(name, '/') + 1);
 239         np->e_namlen = strlen(np->e_name);
 240         np->e_parent = ep;
 241         np->e_sibling = ep->e_entries;
 242         ep->e_entries = np;
 243         if (type & LINK) {
 244                 ep = lookupino(inum);
 245                 if (ep == NULL)
 246                         panic("link to non-existent name\n");
 247                 np->e_ino = inum;
 248                 np->e_links = ep->e_links;
 249                 ep->e_links = np;
 250         } else if (inum != 0) {
 251                 if (lookupino(inum) != NULL)
 252                         panic("duplicate entry\n");
 253                 addino(inum, np);
 254         }
 255         return (np);
 256 }
 257
 258 /*
 259  * delete an entry from the symbol table
 260  */
 261 void
 262 freeentry(struct entry *ep)
 263 {
 264         struct entry *np;
 265         ufs1_ino_t inum;
 266
 267         if (ep->e_flags != REMOVED)
 268                 badentry(ep, "not marked REMOVED");
 269         if (ep->e_type == NODE) {
 270                 if (ep->e_links != NULL)
 271                         badentry(ep, "freeing referenced directory");
 272                 if (ep->e_entries != NULL)
 273                         badentry(ep, "freeing non-empty directory");
 274         }
 275         if (ep->e_ino != 0) {
 276                 np = lookupino(ep->e_ino);
 277                 if (np == NULL)
 278                         badentry(ep, "lookupino failed");
 279                 if (np == ep) {
 280                         inum = ep->e_ino;
 281                         deleteino(inum);
 282                         if (ep->e_links != NULL)
 283                                 addino(inum, ep->e_links);
 284                 } else {
 285                         for (; np != NULL; np = np->e_links) {
 286                                 if (np->e_links == ep) {
 287                                         np->e_links = ep->e_links;
 288                                         break;
 289                                 }
 290                         }
 291                         if (np == NULL)
 292                                 badentry(ep, "link not found");
 293                 }
 294         }
 295         removeentry(ep);
 296         freename(ep->e_name);
 297         ep->e_next = freelist;
 298         freelist = ep;
 299 }
 300
 301 /*
 302  * Relocate an entry in the tree structure
 303  */
 304 void
 305 moveentry(struct entry *ep, const char *newname)
 306 {
 307         struct entry *np;
 308         char *cp;
 309
 310         np = lookupparent(newname);
 311         if (np == NULL)
 312                 badentry(ep, "cannot move ROOT");
 313         if (np != ep->e_parent) {
 314                 removeentry(ep);
 315                 ep->e_parent = np;
 316                 ep->e_sibling = np->e_entries;
 317                 np->e_entries = ep;
 318         }
 319         cp = strrchr(newname, '/') + 1;
 320         freename(ep->e_name);
 321         ep->e_name = savename(cp);
 322         ep->e_namlen = strlen(cp);
 323         if (strcmp(gentempname(ep), ep->e_name) == 0)
 324                 ep->e_flags |= TMPNAME;
 325         else
 326                 ep->e_flags &= ~TMPNAME;
 327 }
 328
 329 /*
 330  * Remove an entry in the tree structure
 331  */
 332 static void
 333 removeentry(struct entry *ep)
 334 {
 335         struct entry *np;
 336
 337         np = ep->e_parent;
 338         if (np->e_entries == ep) {
 339                 np->e_entries = ep->e_sibling;
 340         } else {
 341                 for (np = np->e_entries; np != NULL; np = np->e_sibling) {
 342                         if (np->e_sibling == ep) {
 343                                 np->e_sibling = ep->e_sibling;
 344                                 break;
 345                         }
 346                 }
 347                 if (np == NULL)
 348                         badentry(ep, "cannot find entry in parent list");
 349         }
 350 }
 351
 352 /*
 353  * Table of unused string entries, sorted by length.
 354  *
 355  * Entries are allocated in STRTBLINCR sized pieces so that names
 356  * of similar lengths can use the same entry. The value of STRTBLINCR
 357  * is chosen so that every entry has at least enough space to hold
 358  * a "struct strtbl" header. Thus every entry can be linked onto an
 359  * appropriate free list.
 360  *
 361  * NB. The macro "allocsize" below assumes that "struct strhdr"
 362  *     has a size that is a power of two.
 363  */
 364 struct strhdr {
 365         struct strhdr *next;
 366 };
 367
 368 #define STRTBLINCR      (sizeof(struct strhdr))
 369 #define allocsize(size) roundup2((size) + 1, STRTBLINCR)
 370
 371 static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR];
 372
 373 /*
 374  * Allocate space for a name. It first looks to see if it already
 375  * has an appropriate sized entry, and if not allocates a new one.
 376  */
 377 char *
 378 savename(const char *name)
 379 {
 380         struct strhdr *np;
 381         long len;
 382         char *cp;
 383
 384         if (name == NULL)
 385                 panic("bad name\n");
 386         len = strlen(name);
 387         np = strtblhdr[len / STRTBLINCR].next;
 388         if (np != NULL) {
 389                 strtblhdr[len / STRTBLINCR].next = np->next;
 390                 cp = (char *)np;
 391         } else {
 392                 cp = malloc((unsigned)allocsize(len));
 393                 if (cp == NULL)
 394                         panic("no space for string table\n");
 395         }
 396         strcpy(cp, name);
 397         return (cp);
 398 }
 399
 400 /*
 401  * Free space for a name. The resulting entry is linked onto the
 402  * appropriate free list.
 403  */
 404 void
 405 freename(char *name)
 406 {
 407         struct strhdr *tp, *np;
 408
 409         tp = &strtblhdr[strlen(name) / STRTBLINCR];
 410         np = (struct strhdr *)name;
 411         np->next = tp->next;
 412         tp->next = np;
 413 }
 414
 415 /*
 416  * Useful quantities placed at the end of a dumped symbol table.
 417  */
 418 struct symtableheader {
 419         int32_t volno;
 420         int32_t stringsize;
 421         int32_t entrytblsize;
 422         time_t  dumptime;
 423         time_t  dumpdate;
 424         ufs1_ino_t maxino;
 425         int32_t ntrec;
 426 };
 427
 428 /*
 429  * dump a snapshot of the symbol table
 430  */
 431 void
 432 dumpsymtable(const char *filename, long checkpt)
 433 {
 434         struct entry *ep, *tep;
 435         ufs1_ino_t i;
 436         struct entry temp, *tentry;
 437         long mynum = 1, stroff = 0;
 438         FILE *fd;
 439         struct symtableheader hdr;
 440
 441         vprintf(stdout, "Check pointing the restore\n");
 442         if (Nflag)
 443                 return;
 444         if ((fd = fopen(filename, "w")) == NULL) {
 445                 fprintf(stderr, "fopen: %s\n", strerror(errno));
 446                 panic("cannot create save file %s for symbol table\n",
 447                         filename);
 448                 done(1);
 449         }
 450         clearerr(fd);
 451         /*
 452          * Assign indices to each entry
 453          * Write out the string entries
 454          */
 455         for (i = WINO; i <= maxino; i++) {
 456                 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
 457                         ep->e_index = mynum++;
 458                         fwrite(ep->e_name, sizeof(char),
 459                                (int)allocsize(ep->e_namlen), fd);
 460                 }
 461         }
 462         /*
 463          * Convert pointers to indexes, and output
 464          */
 465         tep = &temp;
 466         stroff = 0;
 467         for (i = WINO; i <= maxino; i++) {
 468                 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
 469                         memmove(tep, ep, (long)sizeof(struct entry));
 470                         tep->e_name = (char *)stroff;
 471                         stroff += allocsize(ep->e_namlen);
 472                         tep->e_parent = (struct entry *)ep->e_parent->e_index;
 473                         if (ep->e_links != NULL)
 474                                 tep->e_links =
 475                                         (struct entry *)ep->e_links->e_index;
 476                         if (ep->e_sibling != NULL)
 477                                 tep->e_sibling =
 478                                         (struct entry *)ep->e_sibling->e_index;
 479                         if (ep->e_entries != NULL)
 480                                 tep->e_entries =
 481                                         (struct entry *)ep->e_entries->e_index;
 482                         if (ep->e_next != NULL)
 483                                 tep->e_next =
 484                                         (struct entry *)ep->e_next->e_index;
 485                         fwrite((char *)tep, sizeof(struct entry), 1, fd);
 486                 }
 487         }
 488         /*
 489          * Convert entry pointers to indexes, and output
 490          */
 491         for (i = 0; i < entrytblsize; i++) {
 492                 if (entry[i] == NULL)
 493                         tentry = NULL;
 494                 else
 495                         tentry = (struct entry *)entry[i]->e_index;
 496                 fwrite((char *)&tentry, sizeof(struct entry *), 1, fd);
 497         }
 498         hdr.volno = checkpt;
 499         hdr.maxino = maxino;
 500         hdr.entrytblsize = entrytblsize;
 501         hdr.stringsize = stroff;
 502         hdr.dumptime = dumptime;
 503         hdr.dumpdate = dumpdate;
 504         hdr.ntrec = ntrec;
 505         fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd);
 506         if (ferror(fd)) {
 507                 fprintf(stderr, "fwrite: %s\n", strerror(errno));
 508                 panic("output error to file %s writing symbol table\n",
 509                         filename);
 510         }
 511         fclose(fd);
 512 }
 513
 514 /*
 515  * Initialize a symbol table from a file
 516  */
 517 void
 518 initsymtable(const char *filename)
 519 {
 520         char *base;
 521         long tblsize;
 522         struct entry *ep;
 523         struct entry *baseep, *lep;
 524         struct symtableheader hdr;
 525         struct stat stbuf;
 526         long i;
 527         int fd;
 528
 529         vprintf(stdout, "Initialize symbol table.\n");
 530         if (filename == NULL) {
 531                 entrytblsize = maxino / HASHFACTOR;
 532                 entry = (struct entry **)
 533                         calloc((unsigned)entrytblsize, sizeof(struct entry *));
 534                 if (entry == NULL)
 535                         panic("no memory for entry table\n");
 536                 ep = addentry(".", ROOTINO, NODE);
 537                 ep->e_flags |= NEW;
 538                 return;
 539         }
 540         if ((fd = open(filename, O_RDONLY, 0)) < 0) {
 541                 fprintf(stderr, "open: %s\n", strerror(errno));
 542                 panic("cannot open symbol table file %s\n", filename);
 543         }
 544         if (fstat(fd, &stbuf) < 0) {
 545                 fprintf(stderr, "stat: %s\n", strerror(errno));
 546                 panic("cannot stat symbol table file %s\n", filename);
 547         }
 548         tblsize = stbuf.st_size - sizeof(struct symtableheader);
 549         base = calloc(sizeof(char), (unsigned)tblsize);
 550         if (base == NULL)
 551                 panic("cannot allocate space for symbol table\n");
 552         if (read(fd, base, (int)tblsize) < 0 ||
 553             read(fd, (char *)&hdr, sizeof(struct symtableheader)) < 0) {
 554                 fprintf(stderr, "read: %s\n", strerror(errno));
 555                 panic("cannot read symbol table file %s\n", filename);
 556         }
 557         switch (command) {
 558         case 'r':
 559                 /*
 560                  * For normal continuation, insure that we are using
 561                  * the next incremental tape
 562                  */
 563                 if (hdr.dumpdate != dumptime) {
 564                         if (hdr.dumpdate < dumptime)
 565                                 fprintf(stderr, "Incremental tape too low\n");
 566                         else
 567                                 fprintf(stderr, "Incremental tape too high\n");
 568                         done(1);
 569                 }
 570                 break;
 571         case 'R':
 572                 /*
 573                  * For restart, insure that we are using the same tape
 574                  */
 575                 curfile.action = SKIP;
 576                 dumptime = hdr.dumptime;
 577                 dumpdate = hdr.dumpdate;
 578                 if (!bflag)
 579                         newtapebuf(hdr.ntrec);
 580                 getvol(hdr.volno);
 581                 break;
 582         default:
 583                 panic("initsymtable called from command %c\n", command);
 584                 break;
 585         }
 586         maxino = hdr.maxino;
 587         entrytblsize = hdr.entrytblsize;
 588         entry = (struct entry **)
 589                 (base + tblsize - (entrytblsize * sizeof(struct entry *)));
 590         baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry));
 591         lep = (struct entry *)entry;
 592         for (i = 0; i < entrytblsize; i++) {
 593                 if (entry[i] == NULL)
 594                         continue;
 595                 entry[i] = &baseep[(long)entry[i]];
 596         }
 597         for (ep = &baseep[1]; ep < lep; ep++) {
 598                 ep->e_name = base + (long)ep->e_name;
 599                 ep->e_parent = &baseep[(long)ep->e_parent];
 600                 if (ep->e_sibling != NULL)
 601                         ep->e_sibling = &baseep[(long)ep->e_sibling];
 602                 if (ep->e_links != NULL)
 603                         ep->e_links = &baseep[(long)ep->e_links];
 604                 if (ep->e_entries != NULL)
 605                         ep->e_entries = &baseep[(long)ep->e_entries];
 606                 if (ep->e_next != NULL)
 607                         ep->e_next = &baseep[(long)ep->e_next];
 608         }
 609 }