1 /* $NetBSD: symtab.c,v 1.19 2003/08/07 10:04:38 agc 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 1.19 2003/08/07 10:04:38 agc 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 __P((ino_t, struct entry *)); 77 static struct entry *lookupparent __P((char *)); 78 static void removeentry __P((struct entry *)); 79 80 /* 81 * Look up an entry by inode number 82 */ 83 struct entry * 84 lookupino(inum) 85 ino_t inum; 86 { 87 struct entry *ep; 88 89 if (inum < WINO || inum >= maxino) 90 return (NULL); 91 for (ep = entry[inum % entrytblsize]; ep != NULL; ep = ep->e_next) 92 if (ep->e_ino == inum) 93 return (ep); 94 return (NULL); 95 } 96 97 /* 98 * Add an entry into the entry table 99 */ 100 static void 101 addino(inum, np) 102 ino_t inum; 103 struct entry *np; 104 { 105 struct entry **epp; 106 107 if (inum < WINO || inum >= maxino) 108 panic("addino: out of range %d\n", inum); 109 epp = &entry[inum % entrytblsize]; 110 np->e_ino = inum; 111 np->e_next = *epp; 112 *epp = np; 113 if (dflag) 114 for (np = np->e_next; np != NULL; np = np->e_next) 115 if (np->e_ino == inum) 116 badentry(np, "duplicate inum"); 117 } 118 119 /* 120 * Delete an entry from the entry table 121 */ 122 void 123 deleteino(inum) 124 ino_t inum; 125 { 126 struct entry *next; 127 struct entry **prev; 128 129 if (inum < WINO || inum >= maxino) 130 panic("deleteino: out of range %d\n", inum); 131 prev = &entry[inum % entrytblsize]; 132 for (next = *prev; next != NULL; next = next->e_next) { 133 if (next->e_ino == inum) { 134 next->e_ino = 0; 135 *prev = next->e_next; 136 return; 137 } 138 prev = &next->e_next; 139 } 140 panic("deleteino: %d not found\n", inum); 141 } 142 143 /* 144 * Look up an entry by name 145 */ 146 struct entry * 147 lookupname(name) 148 char *name; 149 { 150 struct entry *ep; 151 char *np, *cp; 152 char buf[MAXPATHLEN]; 153 154 cp = name; 155 for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) { 156 for (np = buf; *cp != '/' && *cp != '\0'; ) 157 *np++ = *cp++; 158 *np = '\0'; 159 for ( ; ep != NULL; ep = ep->e_sibling) 160 if (strcmp(ep->e_name, buf) == 0) 161 break; 162 if (ep == NULL) 163 break; 164 if (*cp++ == '\0') 165 return (ep); 166 } 167 return (NULL); 168 } 169 170 /* 171 * Look up the parent of a pathname 172 */ 173 static struct entry * 174 lookupparent(name) 175 char *name; 176 { 177 struct entry *ep; 178 char *tailindex; 179 180 tailindex = strrchr(name, '/'); 181 if (tailindex == NULL) 182 return (NULL); 183 *tailindex = '\0'; 184 ep = lookupname(name); 185 *tailindex = '/'; 186 if (ep == NULL) 187 return (NULL); 188 if (ep->e_type != NODE) 189 panic("%s is not a directory\n", name); 190 return (ep); 191 } 192 193 /* 194 * Determine the current pathname of a node or leaf 195 */ 196 char * 197 myname(ep) 198 struct entry *ep; 199 { 200 char *cp; 201 static char namebuf[MAXPATHLEN]; 202 203 for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) { 204 cp -= ep->e_namlen; 205 memmove(cp, ep->e_name, (long)ep->e_namlen); 206 if (ep == lookupino(ROOTINO)) 207 return (cp); 208 *(--cp) = '/'; 209 ep = ep->e_parent; 210 } 211 panic("%s: pathname too long\n", cp); 212 return(cp); 213 } 214 215 /* 216 * Unused symbol table entries are linked together on a freelist 217 * headed by the following pointer. 218 */ 219 static struct entry *freelist = NULL; 220 221 /* 222 * add an entry to the symbol table 223 */ 224 struct entry * 225 addentry(name, inum, type) 226 char *name; 227 ino_t inum; 228 int type; 229 { 230 struct entry *np, *ep; 231 232 if (freelist == NULL) { 233 np = malloc(pagesize); 234 if (np == NULL) 235 panic("no memory to extend symbol table\n"); 236 for (ep = (struct entry *)((char *)np + pagesize) - 1; 237 np <= ep; np++) { 238 np->e_next = freelist; 239 freelist = np; 240 } 241 } 242 np = freelist; 243 freelist = np->e_next; 244 memset(np, 0, (long)sizeof(struct entry)); 245 246 np->e_type = type & ~LINK; 247 ep = lookupparent(name); 248 if (ep == NULL) { 249 if (inum != ROOTINO || lookupino(ROOTINO) != NULL) 250 panic("bad name to addentry %s\n", name); 251 np->e_name = savename(name); 252 np->e_namlen = strlen(name); 253 np->e_parent = np; 254 addino(ROOTINO, np); 255 return (np); 256 } 257 np->e_name = savename(strrchr(name, '/') + 1); 258 np->e_namlen = strlen(np->e_name); 259 np->e_parent = ep; 260 np->e_sibling = ep->e_entries; 261 ep->e_entries = np; 262 if (type & LINK) { 263 ep = lookupino(inum); 264 if (ep == NULL) 265 panic("link to non-existent name\n"); 266 np->e_ino = inum; 267 np->e_links = ep->e_links; 268 ep->e_links = np; 269 } else if (inum != 0) { 270 if (lookupino(inum) != NULL) 271 panic("duplicate entry\n"); 272 addino(inum, np); 273 } 274 return (np); 275 } 276 277 /* 278 * delete an entry from the symbol table 279 */ 280 void 281 freeentry(ep) 282 struct entry *ep; 283 { 284 struct entry *np; 285 ino_t inum; 286 287 if (ep->e_flags != REMOVED) 288 badentry(ep, "not marked REMOVED"); 289 if (ep->e_type == NODE) { 290 if (ep->e_links != NULL) 291 badentry(ep, "freeing referenced directory"); 292 if (ep->e_entries != NULL) 293 badentry(ep, "freeing non-empty directory"); 294 } 295 if (ep->e_ino != 0) { 296 np = lookupino(ep->e_ino); 297 if (np == NULL) 298 badentry(ep, "lookupino failed"); 299 if (np == ep) { 300 inum = ep->e_ino; 301 deleteino(inum); 302 if (ep->e_links != NULL) 303 addino(inum, ep->e_links); 304 } else { 305 for (; np != NULL; np = np->e_links) { 306 if (np->e_links == ep) { 307 np->e_links = ep->e_links; 308 break; 309 } 310 } 311 if (np == NULL) 312 badentry(ep, "link not found"); 313 } 314 } 315 removeentry(ep); 316 freename(ep->e_name); 317 ep->e_next = freelist; 318 freelist = ep; 319 } 320 321 /* 322 * Relocate an entry in the tree structure 323 */ 324 void 325 moveentry(ep, newname) 326 struct entry *ep; 327 char *newname; 328 { 329 struct entry *np; 330 char *cp; 331 332 np = lookupparent(newname); 333 if (np == NULL) 334 badentry(ep, "cannot move ROOT"); 335 if (np != ep->e_parent) { 336 removeentry(ep); 337 ep->e_parent = np; 338 ep->e_sibling = np->e_entries; 339 np->e_entries = ep; 340 } 341 cp = strrchr(newname, '/') + 1; 342 freename(ep->e_name); 343 ep->e_name = savename(cp); 344 ep->e_namlen = strlen(cp); 345 if (strcmp(gentempname(ep), ep->e_name) == 0) 346 ep->e_flags |= TMPNAME; 347 else 348 ep->e_flags &= ~TMPNAME; 349 } 350 351 /* 352 * Remove an entry in the tree structure 353 */ 354 static void 355 removeentry(ep) 356 struct entry *ep; 357 { 358 struct entry *np; 359 360 np = ep->e_parent; 361 if (np->e_entries == ep) { 362 np->e_entries = ep->e_sibling; 363 } else { 364 for (np = np->e_entries; np != NULL; np = np->e_sibling) { 365 if (np->e_sibling == ep) { 366 np->e_sibling = ep->e_sibling; 367 break; 368 } 369 } 370 if (np == NULL) 371 badentry(ep, "cannot find entry in parent list"); 372 } 373 } 374 375 /* 376 * Table of unused string entries, sorted by length. 377 * 378 * Entries are allocated in STRTBLINCR sized pieces so that names 379 * of similar lengths can use the same entry. The value of STRTBLINCR 380 * is chosen so that every entry has at least enough space to hold 381 * a "struct strtbl" header. Thus every entry can be linked onto an 382 * appropriate free list. 383 * 384 * NB. The macro "allocsize" below assumes that "struct strhdr" 385 * has a size that is a power of two. 386 */ 387 struct strhdr { 388 struct strhdr *next; 389 }; 390 391 #define STRTBLINCR (sizeof(struct strhdr)) 392 #define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1)) 393 394 static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR]; 395 396 /* 397 * Allocate space for a name. It first looks to see if it already 398 * has an appropriate sized entry, and if not allocates a new one. 399 */ 400 char * 401 savename(name) 402 char *name; 403 { 404 struct strhdr *np, *tp; 405 long len, siz; 406 char *cp, *ep; 407 408 if (name == NULL) 409 panic("bad name\n"); 410 len = strlen(name); 411 tp = &strtblhdr[len / STRTBLINCR]; 412 if (tp->next == NULL) { 413 cp = malloc(pagesize); 414 if (cp == NULL) 415 panic("no space for string table\n"); 416 for (siz = allocsize(len), ep = (cp + pagesize) - siz; 417 cp <= ep; cp += siz) { 418 np = (struct strhdr *)cp; 419 np->next = tp->next; 420 tp->next = np; 421 } 422 } 423 np = tp->next; 424 tp->next = np->next; 425 cp = (char *)np; 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(name) 436 char *name; 437 { 438 struct strhdr *tp, *np; 439 440 tp = &strtblhdr[strlen(name) / STRTBLINCR]; 441 np = (struct strhdr *)name; 442 np->next = tp->next; 443 tp->next = np; 444 } 445 446 /* 447 * Useful quantities placed at the end of a dumped symbol table. 448 */ 449 struct symtableheader { 450 int32_t volno; 451 int32_t stringsize; 452 int32_t entrytblsize; 453 time_t dumptime; 454 time_t dumpdate; 455 ino_t maxino; 456 int32_t ntrec; 457 }; 458 459 /* 460 * dump a snapshot of the symbol table 461 */ 462 void 463 dumpsymtable(filename, checkpt) 464 char *filename; 465 int32_t checkpt; 466 { 467 struct entry *ep, *tep; 468 ino_t i; 469 struct entry temp, *tentry; 470 long mynum = 1, stroff = 0; 471 FILE *fd; 472 struct symtableheader hdr; 473 474 vprintf(stdout, "Check pointing the restore\n"); 475 if (Nflag) 476 return; 477 if ((fd = fopen(filename, "w")) == NULL) { 478 fprintf(stderr, "fopen: %s\n", strerror(errno)); 479 panic("cannot create save file %s for symbol table\n", 480 filename); 481 } 482 clearerr(fd); 483 /* 484 * Assign indicies to each entry 485 * Write out the string entries 486 */ 487 for (i = WINO; i <= maxino; i++) { 488 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) { 489 ep->e_index = mynum++; 490 (void) fwrite(ep->e_name, sizeof(char), 491 (int)allocsize(ep->e_namlen), fd); 492 } 493 } 494 /* 495 * Convert pointers to indexes, and output 496 */ 497 tep = &temp; 498 stroff = 0; 499 for (i = WINO; i <= maxino; i++) { 500 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) { 501 memmove(tep, ep, (long)sizeof(struct entry)); 502 tep->e_name = (char *)stroff; 503 stroff += allocsize(ep->e_namlen); 504 tep->e_parent = (struct entry *)(long) 505 ep->e_parent->e_index; 506 if (ep->e_links != NULL) 507 tep->e_links = (struct entry *)(long) 508 ep->e_links->e_index; 509 if (ep->e_sibling != NULL) 510 tep->e_sibling = (struct entry *)(long) 511 ep->e_sibling->e_index; 512 if (ep->e_entries != NULL) 513 tep->e_entries = (struct entry *)(long) 514 ep->e_entries->e_index; 515 if (ep->e_next != NULL) 516 tep->e_next = (struct entry *)(long) 517 ep->e_next->e_index; 518 (void) fwrite((char *)tep, sizeof(struct entry), 1, fd); 519 } 520 } 521 /* 522 * Convert entry pointers to indexes, and output 523 */ 524 for (i = 0; i < entrytblsize; i++) { 525 if (entry[i] == NULL) 526 tentry = NULL; 527 else 528 tentry = (struct entry *)(long)entry[i]->e_index; 529 (void) fwrite((char *)&tentry, sizeof(struct entry *), 1, fd); 530 } 531 hdr.volno = checkpt; 532 hdr.maxino = maxino; 533 hdr.entrytblsize = entrytblsize; 534 hdr.stringsize = stroff; 535 hdr.dumptime = dumptime; 536 hdr.dumpdate = dumpdate; 537 hdr.ntrec = ntrec; 538 (void) fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd); 539 if (ferror(fd)) { 540 fprintf(stderr, "fwrite: %s\n", strerror(errno)); 541 panic("output error to file %s writing symbol table\n", 542 filename); 543 } 544 (void) fclose(fd); 545 } 546 547 /* 548 * Initialize a symbol table from a file 549 */ 550 void 551 initsymtable(filename) 552 char *filename; 553 { 554 char *base; 555 long tblsize; 556 struct entry *ep; 557 struct entry *baseep, *lep; 558 struct symtableheader hdr; 559 struct stat stbuf; 560 long i; 561 int fd; 562 563 vprintf(stdout, "Initialize symbol table.\n"); 564 if (filename == NULL) { 565 entrytblsize = maxino / HASHFACTOR; 566 entry = (struct entry **) 567 calloc((unsigned)entrytblsize, sizeof(struct entry *)); 568 if (entry == (struct entry **)NULL) 569 panic("no memory for entry table\n"); 570 ep = addentry(".", ROOTINO, NODE); 571 ep->e_flags |= NEW; 572 return; 573 } 574 if ((fd = open(filename, O_RDONLY, 0)) < 0) { 575 fprintf(stderr, "open: %s\n", strerror(errno)); 576 panic("cannot open symbol table file %s\n", filename); 577 } 578 if (fstat(fd, &stbuf) < 0) { 579 fprintf(stderr, "stat: %s\n", strerror(errno)); 580 panic("cannot stat symbol table file %s\n", filename); 581 } 582 tblsize = stbuf.st_size - sizeof(struct symtableheader); 583 base = calloc((unsigned)tblsize, sizeof(char)); 584 if (base == NULL) 585 panic("cannot allocate space for symbol table\n"); 586 if (read(fd, base, (int)tblsize) < 0 || 587 read(fd, (char *)&hdr, sizeof(struct symtableheader)) < 0) { 588 fprintf(stderr, "read: %s\n", strerror(errno)); 589 panic("cannot read symbol table file %s\n", filename); 590 } 591 switch (command) { 592 case 'r': 593 /* 594 * For normal continuation, insure that we are using 595 * the next incremental tape 596 */ 597 if (hdr.dumpdate != dumptime) { 598 if (hdr.dumpdate < dumptime) 599 fprintf(stderr, "Incremental tape too low\n"); 600 else 601 fprintf(stderr, "Incremental tape too high\n"); 602 exit(1); 603 } 604 break; 605 case 'R': 606 /* 607 * For restart, insure that we are using the same tape 608 */ 609 curfile.action = SKIP; 610 dumptime = hdr.dumptime; 611 dumpdate = hdr.dumpdate; 612 if (!bflag) 613 newtapebuf(hdr.ntrec); 614 getvol(hdr.volno); 615 break; 616 default: 617 panic("initsymtable called from command %c\n", command); 618 break; 619 } 620 maxino = hdr.maxino; 621 entrytblsize = hdr.entrytblsize; 622 entry = (struct entry **) 623 (base + tblsize - (entrytblsize * sizeof(struct entry *))); 624 baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry)); 625 lep = (struct entry *)entry; 626 for (i = 0; i < entrytblsize; i++) { 627 if (entry[i] == NULL) 628 continue; 629 entry[i] = &baseep[(long)entry[i]]; 630 } 631 for (ep = &baseep[1]; ep < lep; ep++) { 632 ep->e_name = base + (long)ep->e_name; 633 ep->e_parent = &baseep[(long)ep->e_parent]; 634 if (ep->e_sibling != NULL) 635 ep->e_sibling = &baseep[(long)ep->e_sibling]; 636 if (ep->e_links != NULL) 637 ep->e_links = &baseep[(long)ep->e_links]; 638 if (ep->e_entries != NULL) 639 ep->e_entries = &baseep[(long)ep->e_entries]; 640 if (ep->e_next != NULL) 641 ep->e_next = &baseep[(long)ep->e_next]; 642 } 643 } 644