1 /* $NetBSD: symtab.c,v 1.31 2024/02/10 08:24:50 andvar 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 1.31 2024/02/10 08:24:50 andvar 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 < UFS_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 < UFS_WINO || inum >= maxino) 105 panic("addino: out of range %ju\n", (uintmax_t)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 < UFS_WINO || inum >= maxino) 126 panic("deleteino: out of range %ju\n", 127 (uintmax_t)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: %ju not found\n", (uintmax_t)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(UFS_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(UFS_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 != UFS_ROOTINO || lookupino(UFS_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(UFS_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, "Checkpointing 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 indices to each entry 470 * Write out the string entries 471 */ 472 for (i = UFS_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 = UFS_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 == NULL) 553 panic("no memory for entry table\n"); 554 ep = addentry(".", UFS_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 (void)close(fd); 576 switch (command) { 577 case 'r': 578 /* 579 * For normal continuation, insure that we are using 580 * the next incremental tape 581 */ 582 if (hdr.dumpdate != dumptime) { 583 if (hdr.dumpdate < dumptime) 584 fprintf(stderr, "Incremental tape too low\n"); 585 else 586 fprintf(stderr, "Incremental tape too high\n"); 587 exit(1); 588 } 589 break; 590 case 'R': 591 /* 592 * For restart, insure that we are using the same tape 593 */ 594 curfile.action = SKIP; 595 dumptime = hdr.dumptime; 596 dumpdate = hdr.dumpdate; 597 if (!bflag) 598 newtapebuf(hdr.ntrec); 599 getvol(hdr.volno); 600 break; 601 default: 602 panic("initsymtable called from command %c\n", command); 603 break; 604 } 605 maxino = hdr.maxino; 606 entrytblsize = hdr.entrytblsize; 607 entry = (struct entry **) 608 (base + tblsize - (entrytblsize * sizeof(struct entry *))); 609 baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry)); 610 lep = (struct entry *)entry; 611 for (i = 0; i < entrytblsize; i++) { 612 if (entry[i] == NULL) 613 continue; 614 entry[i] = &baseep[(long)entry[i]]; 615 } 616 for (ep = &baseep[1]; ep < lep; ep++) { 617 ep->e_name = base + (long)ep->e_name; 618 ep->e_parent = &baseep[(long)ep->e_parent]; 619 if (ep->e_sibling != NULL) 620 ep->e_sibling = &baseep[(long)ep->e_sibling]; 621 if (ep->e_links != NULL) 622 ep->e_links = &baseep[(long)ep->e_links]; 623 if (ep->e_entries != NULL) 624 ep->e_entries = &baseep[(long)ep->e_entries]; 625 if (ep->e_next != NULL) 626 ep->e_next = &baseep[(long)ep->e_next]; 627 } 628 } 629
Indexes created Sun Sep 21 14:09:52 GMT 2025