1 /* $NetBSD: symtab.c,v 1.18 2002/11/25 07:16:17 enami 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #ifndef lint 38 #if 0 39 static char sccsid[] = "@(#)symtab.c 8.3 (Berkeley) 4/28/95"; 40 #else 41 __RCSID("$NetBSD: symtab.c,v 1.18 2002/11/25 07:16:17 enami Exp $"); 42 #endif 43 #endif /* not lint */ 44 45 /* 46 * These routines maintain the symbol table which tracks the state 47 * of the file system being restored. They provide lookup by either 48 * name or inode number. They also provide for creation, deletion, 49 * and renaming of entries. Because of the dynamic nature of pathnames, 50 * names should not be saved, but always constructed just before they 51 * are needed, by calling "myname". 52 */ 53 54 #include <sys/param.h> 55 #include <sys/stat.h> 56 57 #include <ufs/ufs/dinode.h> 58 59 #include <errno.h> 60 #include <fcntl.h> 61 #include <stdio.h> 62 #include <stdlib.h> 63 #include <string.h> 64 #include <unistd.h> 65 66 #include "restore.h" 67 #include "extern.h" 68 69 /* 70 * The following variables define the inode symbol table. 71 * The primary hash table is dynamically allocated based on 72 * the number of inodes in the file system (maxino), scaled by 73 * HASHFACTOR. The variable "entry" points to the hash table; 74 * the variable "entrytblsize" indicates its size (in entries). 75 */ 76 #define HASHFACTOR 5 77 static struct entry **entry; 78 static long entrytblsize; 79 80 static void addino __P((ino_t, struct entry *)); 81 static struct entry *lookupparent __P((char *)); 82 static void removeentry __P((struct entry *)); 83 84 /* 85 * Look up an entry by inode number 86 */ 87 struct entry * 88 lookupino(inum) 89 ino_t inum; 90 { 91 struct entry *ep; 92 93 if (inum < WINO || inum >= maxino) 94 return (NULL); 95 for (ep = entry[inum % entrytblsize]; ep != NULL; ep = ep->e_next) 96 if (ep->e_ino == inum) 97 return (ep); 98 return (NULL); 99 } 100 101 /* 102 * Add an entry into the entry table 103 */ 104 static void 105 addino(inum, np) 106 ino_t inum; 107 struct entry *np; 108 { 109 struct entry **epp; 110 111 if (inum < WINO || inum >= maxino) 112 panic("addino: out of range %d\n", inum); 113 epp = &entry[inum % entrytblsize]; 114 np->e_ino = inum; 115 np->e_next = *epp; 116 *epp = np; 117 if (dflag) 118 for (np = np->e_next; np != NULL; np = np->e_next) 119 if (np->e_ino == inum) 120 badentry(np, "duplicate inum"); 121 } 122 123 /* 124 * Delete an entry from the entry table 125 */ 126 void 127 deleteino(inum) 128 ino_t inum; 129 { 130 struct entry *next; 131 struct entry **prev; 132 133 if (inum < WINO || inum >= maxino) 134 panic("deleteino: out of range %d\n", inum); 135 prev = &entry[inum % entrytblsize]; 136 for (next = *prev; next != NULL; next = next->e_next) { 137 if (next->e_ino == inum) { 138 next->e_ino = 0; 139 *prev = next->e_next; 140 return; 141 } 142 prev = &next->e_next; 143 } 144 panic("deleteino: %d not found\n", inum); 145 } 146 147 /* 148 * Look up an entry by name 149 */ 150 struct entry * 151 lookupname(name) 152 char *name; 153 { 154 struct entry *ep; 155 char *np, *cp; 156 char buf[MAXPATHLEN]; 157 158 cp = name; 159 for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) { 160 for (np = buf; *cp != '/' && *cp != '\0'; ) 161 *np++ = *cp++; 162 *np = '\0'; 163 for ( ; ep != NULL; ep = ep->e_sibling) 164 if (strcmp(ep->e_name, buf) == 0) 165 break; 166 if (ep == NULL) 167 break; 168 if (*cp++ == '\0') 169 return (ep); 170 } 171 return (NULL); 172 } 173 174 /* 175 * Look up the parent of a pathname 176 */ 177 static struct entry * 178 lookupparent(name) 179 char *name; 180 { 181 struct entry *ep; 182 char *tailindex; 183 184 tailindex = strrchr(name, '/'); 185 if (tailindex == NULL) 186 return (NULL); 187 *tailindex = '\0'; 188 ep = lookupname(name); 189 *tailindex = '/'; 190 if (ep == NULL) 191 return (NULL); 192 if (ep->e_type != NODE) 193 panic("%s is not a directory\n", name); 194 return (ep); 195 } 196 197 /* 198 * Determine the current pathname of a node or leaf 199 */ 200 char * 201 myname(ep) 202 struct entry *ep; 203 { 204 char *cp; 205 static char namebuf[MAXPATHLEN]; 206 207 for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) { 208 cp -= ep->e_namlen; 209 memmove(cp, ep->e_name, (long)ep->e_namlen); 210 if (ep == lookupino(ROOTINO)) 211 return (cp); 212 *(--cp) = '/'; 213 ep = ep->e_parent; 214 } 215 panic("%s: pathname too long\n", cp); 216 return(cp); 217 } 218 219 /* 220 * Unused symbol table entries are linked together on a freelist 221 * headed by the following pointer. 222 */ 223 static struct entry *freelist = NULL; 224 225 /* 226 * add an entry to the symbol table 227 */ 228 struct entry * 229 addentry(name, inum, type) 230 char *name; 231 ino_t inum; 232 int type; 233 { 234 struct entry *np, *ep; 235 236 if (freelist == NULL) { 237 np = malloc(pagesize); 238 if (np == NULL) 239 panic("no memory to extend symbol table\n"); 240 for (ep = (struct entry *)((char *)np + pagesize) - 1; 241 np <= ep; np++) { 242 np->e_next = freelist; 243 freelist = np; 244 } 245 } 246 np = freelist; 247 freelist = np->e_next; 248 memset(np, 0, (long)sizeof(struct entry)); 249 250 np->e_type = type & ~LINK; 251 ep = lookupparent(name); 252 if (ep == NULL) { 253 if (inum != ROOTINO || lookupino(ROOTINO) != NULL) 254 panic("bad name to addentry %s\n", name); 255 np->e_name = savename(name); 256 np->e_namlen = strlen(name); 257 np->e_parent = np; 258 addino(ROOTINO, np); 259 return (np); 260 } 261 np->e_name = savename(strrchr(name, '/') + 1); 262 np->e_namlen = strlen(np->e_name); 263 np->e_parent = ep; 264 np->e_sibling = ep->e_entries; 265 ep->e_entries = np; 266 if (type & LINK) { 267 ep = lookupino(inum); 268 if (ep == NULL) 269 panic("link to non-existent name\n"); 270 np->e_ino = inum; 271 np->e_links = ep->e_links; 272 ep->e_links = np; 273 } else if (inum != 0) { 274 if (lookupino(inum) != NULL) 275 panic("duplicate entry\n"); 276 addino(inum, np); 277 } 278 return (np); 279 } 280 281 /* 282 * delete an entry from the symbol table 283 */ 284 void 285 freeentry(ep) 286 struct entry *ep; 287 { 288 struct entry *np; 289 ino_t inum; 290 291 if (ep->e_flags != REMOVED) 292 badentry(ep, "not marked REMOVED"); 293 if (ep->e_type == NODE) { 294 if (ep->e_links != NULL) 295 badentry(ep, "freeing referenced directory"); 296 if (ep->e_entries != NULL) 297 badentry(ep, "freeing non-empty directory"); 298 } 299 if (ep->e_ino != 0) { 300 np = lookupino(ep->e_ino); 301 if (np == NULL) 302 badentry(ep, "lookupino failed"); 303 if (np == ep) { 304 inum = ep->e_ino; 305 deleteino(inum); 306 if (ep->e_links != NULL) 307 addino(inum, ep->e_links); 308 } else { 309 for (; np != NULL; np = np->e_links) { 310 if (np->e_links == ep) { 311 np->e_links = ep->e_links; 312 break; 313 } 314 } 315 if (np == NULL) 316 badentry(ep, "link not found"); 317 } 318 } 319 removeentry(ep); 320 freename(ep->e_name); 321 ep->e_next = freelist; 322 freelist = ep; 323 } 324 325 /* 326 * Relocate an entry in the tree structure 327 */ 328 void 329 moveentry(ep, newname) 330 struct entry *ep; 331 char *newname; 332 { 333 struct entry *np; 334 char *cp; 335 336 np = lookupparent(newname); 337 if (np == NULL) 338 badentry(ep, "cannot move ROOT"); 339 if (np != ep->e_parent) { 340 removeentry(ep); 341 ep->e_parent = np; 342 ep->e_sibling = np->e_entries; 343 np->e_entries = ep; 344 } 345 cp = strrchr(newname, '/') + 1; 346 freename(ep->e_name); 347 ep->e_name = savename(cp); 348 ep->e_namlen = strlen(cp); 349 if (strcmp(gentempname(ep), ep->e_name) == 0) 350 ep->e_flags |= TMPNAME; 351 else 352 ep->e_flags &= ~TMPNAME; 353 } 354 355 /* 356 * Remove an entry in the tree structure 357 */ 358 static void 359 removeentry(ep) 360 struct entry *ep; 361 { 362 struct entry *np; 363 364 np = ep->e_parent; 365 if (np->e_entries == ep) { 366 np->e_entries = ep->e_sibling; 367 } else { 368 for (np = np->e_entries; np != NULL; np = np->e_sibling) { 369 if (np->e_sibling == ep) { 370 np->e_sibling = ep->e_sibling; 371 break; 372 } 373 } 374 if (np == NULL) 375 badentry(ep, "cannot find entry in parent list"); 376 } 377 } 378 379 /* 380 * Table of unused string entries, sorted by length. 381 * 382 * Entries are allocated in STRTBLINCR sized pieces so that names 383 * of similar lengths can use the same entry. The value of STRTBLINCR 384 * is chosen so that every entry has at least enough space to hold 385 * a "struct strtbl" header. Thus every entry can be linked onto an 386 * appropriate free list. 387 * 388 * NB. The macro "allocsize" below assumes that "struct strhdr" 389 * has a size that is a power of two. 390 */ 391 struct strhdr { 392 struct strhdr *next; 393 }; 394 395 #define STRTBLINCR (sizeof(struct strhdr)) 396 #define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1)) 397 398 static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR]; 399 400 /* 401 * Allocate space for a name. It first looks to see if it already 402 * has an appropriate sized entry, and if not allocates a new one. 403 */ 404 char * 405 savename(name) 406 char *name; 407 { 408 struct strhdr *np, *tp; 409 long len, siz; 410 char *cp, *ep; 411 412 if (name == NULL) 413 panic("bad name\n"); 414 len = strlen(name); 415 tp = &strtblhdr[len / STRTBLINCR]; 416 if (tp->next == NULL) { 417 cp = malloc(pagesize); 418 if (cp == NULL) 419 panic("no space for string table\n"); 420 for (siz = allocsize(len), ep = (cp + pagesize) - siz; 421 cp <= ep; cp += siz) { 422 np = (struct strhdr *)cp; 423 np->next = tp->next; 424 tp->next = np; 425 } 426 } 427 np = tp->next; 428 tp->next = np->next; 429 cp = (char *)np; 430 (void) strcpy(cp, name); 431 return (cp); 432 } 433 434 /* 435 * Free space for a name. The resulting entry is linked onto the 436 * appropriate free list. 437 */ 438 void 439 freename(name) 440 char *name; 441 { 442 struct strhdr *tp, *np; 443 444 tp = &strtblhdr[strlen(name) / STRTBLINCR]; 445 np = (struct strhdr *)name; 446 np->next = tp->next; 447 tp->next = np; 448 } 449 450 /* 451 * Useful quantities placed at the end of a dumped symbol table. 452 */ 453 struct symtableheader { 454 int32_t volno; 455 int32_t stringsize; 456 int32_t entrytblsize; 457 time_t dumptime; 458 time_t dumpdate; 459 ino_t maxino; 460 int32_t ntrec; 461 }; 462 463 /* 464 * dump a snapshot of the symbol table 465 */ 466 void 467 dumpsymtable(filename, checkpt) 468 char *filename; 469 int32_t checkpt; 470 { 471 struct entry *ep, *tep; 472 ino_t i; 473 struct entry temp, *tentry; 474 long mynum = 1, stroff = 0; 475 FILE *fd; 476 struct symtableheader hdr; 477 478 vprintf(stdout, "Check pointing the restore\n"); 479 if (Nflag) 480 return; 481 if ((fd = fopen(filename, "w")) == NULL) { 482 fprintf(stderr, "fopen: %s\n", strerror(errno)); 483 panic("cannot create save file %s for symbol table\n", 484 filename); 485 } 486 clearerr(fd); 487 /* 488 * Assign indicies to each entry 489 * Write out the string entries 490 */ 491 for (i = WINO; i <= maxino; i++) { 492 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) { 493 ep->e_index = mynum++; 494 (void) fwrite(ep->e_name, sizeof(char), 495 (int)allocsize(ep->e_namlen), fd); 496 } 497 } 498 /* 499 * Convert pointers to indexes, and output 500 */ 501 tep = &temp; 502 stroff = 0; 503 for (i = WINO; i <= maxino; i++) { 504 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) { 505 memmove(tep, ep, (long)sizeof(struct entry)); 506 tep->e_name = (char *)stroff; 507 stroff += allocsize(ep->e_namlen); 508 tep->e_parent = (struct entry *)(long) 509 ep->e_parent->e_index; 510 if (ep->e_links != NULL) 511 tep->e_links = (struct entry *)(long) 512 ep->e_links->e_index; 513 if (ep->e_sibling != NULL) 514 tep->e_sibling = (struct entry *)(long) 515 ep->e_sibling->e_index; 516 if (ep->e_entries != NULL) 517 tep->e_entries = (struct entry *)(long) 518 ep->e_entries->e_index; 519 if (ep->e_next != NULL) 520 tep->e_next = (struct entry *)(long) 521 ep->e_next->e_index; 522 (void) fwrite((char *)tep, sizeof(struct entry), 1, fd); 523 } 524 } 525 /* 526 * Convert entry pointers to indexes, and output 527 */ 528 for (i = 0; i < entrytblsize; i++) { 529 if (entry[i] == NULL) 530 tentry = NULL; 531 else 532 tentry = (struct entry *)(long)entry[i]->e_index; 533 (void) fwrite((char *)&tentry, sizeof(struct entry *), 1, fd); 534 } 535 hdr.volno = checkpt; 536 hdr.maxino = maxino; 537 hdr.entrytblsize = entrytblsize; 538 hdr.stringsize = stroff; 539 hdr.dumptime = dumptime; 540 hdr.dumpdate = dumpdate; 541 hdr.ntrec = ntrec; 542 (void) fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd); 543 if (ferror(fd)) { 544 fprintf(stderr, "fwrite: %s\n", strerror(errno)); 545 panic("output error to file %s writing symbol table\n", 546 filename); 547 } 548 (void) fclose(fd); 549 } 550 551 /* 552 * Initialize a symbol table from a file 553 */ 554 void 555 initsymtable(filename) 556 char *filename; 557 { 558 char *base; 559 long tblsize; 560 struct entry *ep; 561 struct entry *baseep, *lep; 562 struct symtableheader hdr; 563 struct stat stbuf; 564 long i; 565 int fd; 566 567 vprintf(stdout, "Initialize symbol table.\n"); 568 if (filename == NULL) { 569 entrytblsize = maxino / HASHFACTOR; 570 entry = (struct entry **) 571 calloc((unsigned)entrytblsize, sizeof(struct entry *)); 572 if (entry == (struct entry **)NULL) 573 panic("no memory for entry table\n"); 574 ep = addentry(".", ROOTINO, NODE); 575 ep->e_flags |= NEW; 576 return; 577 } 578 if ((fd = open(filename, O_RDONLY, 0)) < 0) { 579 fprintf(stderr, "open: %s\n", strerror(errno)); 580 panic("cannot open symbol table file %s\n", filename); 581 } 582 if (fstat(fd, &stbuf) < 0) { 583 fprintf(stderr, "stat: %s\n", strerror(errno)); 584 panic("cannot stat symbol table file %s\n", filename); 585 } 586 tblsize = stbuf.st_size - sizeof(struct symtableheader); 587 base = calloc((unsigned)tblsize, sizeof(char)); 588 if (base == NULL) 589 panic("cannot allocate space for symbol table\n"); 590 if (read(fd, base, (int)tblsize) < 0 || 591 read(fd, (char *)&hdr, sizeof(struct symtableheader)) < 0) { 592 fprintf(stderr, "read: %s\n", strerror(errno)); 593 panic("cannot read symbol table file %s\n", filename); 594 } 595 switch (command) { 596 case 'r': 597 /* 598 * For normal continuation, insure that we are using 599 * the next incremental tape 600 */ 601 if (hdr.dumpdate != dumptime) { 602 if (hdr.dumpdate < dumptime) 603 fprintf(stderr, "Incremental tape too low\n"); 604 else 605 fprintf(stderr, "Incremental tape too high\n"); 606 exit(1); 607 } 608 break; 609 case 'R': 610 /* 611 * For restart, insure that we are using the same tape 612 */ 613 curfile.action = SKIP; 614 dumptime = hdr.dumptime; 615 dumpdate = hdr.dumpdate; 616 if (!bflag) 617 newtapebuf(hdr.ntrec); 618 getvol(hdr.volno); 619 break; 620 default: 621 panic("initsymtable called from command %c\n", command); 622 break; 623 } 624 maxino = hdr.maxino; 625 entrytblsize = hdr.entrytblsize; 626 entry = (struct entry **) 627 (base + tblsize - (entrytblsize * sizeof(struct entry *))); 628 baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry)); 629 lep = (struct entry *)entry; 630 for (i = 0; i < entrytblsize; i++) { 631 if (entry[i] == NULL) 632 continue; 633 entry[i] = &baseep[(long)entry[i]]; 634 } 635 for (ep = &baseep[1]; ep < lep; ep++) { 636 ep->e_name = base + (long)ep->e_name; 637 ep->e_parent = &baseep[(long)ep->e_parent]; 638 if (ep->e_sibling != NULL) 639 ep->e_sibling = &baseep[(long)ep->e_sibling]; 640 if (ep->e_links != NULL) 641 ep->e_links = &baseep[(long)ep->e_links]; 642 if (ep->e_entries != NULL) 643 ep->e_entries = &baseep[(long)ep->e_entries]; 644 if (ep->e_next != NULL) 645 ep->e_next = &baseep[(long)ep->e_next]; 646 } 647 } 648