1 /* $NetBSD: symtab.c,v 1.20 2005/02/17 15:00:33 xtraeme 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 1.20 2005/02/17 15:00:33 xtraeme 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(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 < 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 < WINO || inum >= maxino) 105 panic("addino: out of range %d\n", 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 < WINO || inum >= maxino) 126 panic("deleteino: out of range %d\n", inum); 127 prev = &entry[inum % entrytblsize]; 128 for (next = *prev; next != NULL; next = next->e_next) { 129 if (next->e_ino == inum) { 130 next->e_ino = 0; 131 *prev = next->e_next; 132 return; 133 } 134 prev = &next->e_next; 135 } 136 panic("deleteino: %d not found\n", inum); 137 } 138 139 /* 140 * Look up an entry by name 141 */ 142 struct entry * 143 lookupname(char *name) 144 { 145 struct entry *ep; 146 char *np, *cp; 147 char buf[MAXPATHLEN]; 148 149 cp = name; 150 for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) { 151 for (np = buf; *cp != '/' && *cp != '\0'; ) 152 *np++ = *cp++; 153 *np = '\0'; 154 for ( ; ep != NULL; ep = ep->e_sibling) 155 if (strcmp(ep->e_name, buf) == 0) 156 break; 157 if (ep == NULL) 158 break; 159 if (*cp++ == '\0') 160 return (ep); 161 } 162 return (NULL); 163 } 164 165 /* 166 * Look up the parent of a pathname 167 */ 168 static struct entry * 169 lookupparent(char *name) 170 { 171 struct entry *ep; 172 char *tailindex; 173 174 tailindex = strrchr(name, '/'); 175 if (tailindex == NULL) 176 return (NULL); 177 *tailindex = '\0'; 178 ep = lookupname(name); 179 *tailindex = '/'; 180 if (ep == NULL) 181 return (NULL); 182 if (ep->e_type != NODE) 183 panic("%s is not a directory\n", name); 184 return (ep); 185 } 186 187 /* 188 * Determine the current pathname of a node or leaf 189 */ 190 char * 191 myname(struct entry *ep) 192 { 193 char *cp; 194 static char namebuf[MAXPATHLEN]; 195 196 for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) { 197 cp -= ep->e_namlen; 198 memmove(cp, ep->e_name, (long)ep->e_namlen); 199 if (ep == lookupino(ROOTINO)) 200 return (cp); 201 *(--cp) = '/'; 202 ep = ep->e_parent; 203 } 204 panic("%s: pathname too long\n", cp); 205 return(cp); 206 } 207 208 /* 209 * Unused symbol table entries are linked together on a freelist 210 * headed by the following pointer. 211 */ 212 static struct entry *freelist = NULL; 213 214 /* 215 * add an entry to the symbol table 216 */ 217 struct entry * 218 addentry(char *name, ino_t inum, int type) 219 { 220 struct entry *np, *ep; 221 222 if (freelist == NULL) { 223 np = malloc(pagesize); 224 if (np == NULL) 225 panic("no memory to extend symbol table\n"); 226 for (ep = (struct entry *)((char *)np + pagesize) - 1; 227 np <= ep; np++) { 228 np->e_next = freelist; 229 freelist = np; 230 } 231 } 232 np = freelist; 233 freelist = np->e_next; 234 memset(np, 0, (long)sizeof(struct entry)); 235 236 np->e_type = type & ~LINK; 237 ep = lookupparent(name); 238 if (ep == NULL) { 239 if (inum != ROOTINO || lookupino(ROOTINO) != NULL) 240 panic("bad name to addentry %s\n", name); 241 np->e_name = savename(name); 242 np->e_namlen = strlen(name); 243 np->e_parent = np; 244 addino(ROOTINO, np); 245 return (np); 246 } 247 np->e_name = savename(strrchr(name, '/') + 1); 248 np->e_namlen = strlen(np->e_name); 249 np->e_parent = ep; 250 np->e_sibling = ep->e_entries; 251 ep->e_entries = np; 252 if (type & LINK) { 253 ep = lookupino(inum); 254 if (ep == NULL) 255 panic("link to non-existent name\n"); 256 np->e_ino = inum; 257 np->e_links = ep->e_links; 258 ep->e_links = np; 259 } else if (inum != 0) { 260 if (lookupino(inum) != NULL) 261 panic("duplicate entry\n"); 262 addino(inum, np); 263 } 264 return (np); 265 } 266 267 /* 268 * delete an entry from the symbol table 269 */ 270 void 271 freeentry(struct entry *ep) 272 { 273 struct entry *np; 274 ino_t inum; 275 276 if (ep->e_flags != REMOVED) 277 badentry(ep, "not marked REMOVED"); 278 if (ep->e_type == NODE) { 279 if (ep->e_links != NULL) 280 badentry(ep, "freeing referenced directory"); 281 if (ep->e_entries != NULL) 282 badentry(ep, "freeing non-empty directory"); 283 } 284 if (ep->e_ino != 0) { 285 np = lookupino(ep->e_ino); 286 if (np == NULL) 287 badentry(ep, "lookupino failed"); 288 if (np == ep) { 289 inum = ep->e_ino; 290 deleteino(inum); 291 if (ep->e_links != NULL) 292 addino(inum, ep->e_links); 293 } else { 294 for (; np != NULL; np = np->e_links) { 295 if (np->e_links == ep) { 296 np->e_links = ep->e_links; 297 break; 298 } 299 } 300 if (np == NULL) 301 badentry(ep, "link not found"); 302 } 303 } 304 removeentry(ep); 305 freename(ep->e_name); 306 ep->e_next = freelist; 307 freelist = ep; 308 } 309 310 /* 311 * Relocate an entry in the tree structure 312 */ 313 void 314 moveentry(struct entry *ep, char *newname) 315 { 316 struct entry *np; 317 char *cp; 318 319 np = lookupparent(newname); 320 if (np == NULL) 321 badentry(ep, "cannot move ROOT"); 322 if (np != ep->e_parent) { 323 removeentry(ep); 324 ep->e_parent = np; 325 ep->e_sibling = np->e_entries; 326 np->e_entries = ep; 327 } 328 cp = strrchr(newname, '/') + 1; 329 freename(ep->e_name); 330 ep->e_name = savename(cp); 331 ep->e_namlen = strlen(cp); 332 if (strcmp(gentempname(ep), ep->e_name) == 0) 333 ep->e_flags |= TMPNAME; 334 else 335 ep->e_flags &= ~TMPNAME; 336 } 337 338 /* 339 * Remove an entry in the tree structure 340 */ 341 static void 342 removeentry(struct entry *ep) 343 { 344 struct entry *np; 345 346 np = ep->e_parent; 347 if (np->e_entries == ep) { 348 np->e_entries = ep->e_sibling; 349 } else { 350 for (np = np->e_entries; np != NULL; np = np->e_sibling) { 351 if (np->e_sibling == ep) { 352 np->e_sibling = ep->e_sibling; 353 break; 354 } 355 } 356 if (np == NULL) 357 badentry(ep, "cannot find entry in parent list"); 358 } 359 } 360 361 /* 362 * Table of unused string entries, sorted by length. 363 * 364 * Entries are allocated in STRTBLINCR sized pieces so that names 365 * of similar lengths can use the same entry. The value of STRTBLINCR 366 * is chosen so that every entry has at least enough space to hold 367 * a "struct strtbl" header. Thus every entry can be linked onto an 368 * appropriate free list. 369 * 370 * NB. The macro "allocsize" below assumes that "struct strhdr" 371 * has a size that is a power of two. 372 */ 373 struct strhdr { 374 struct strhdr *next; 375 }; 376 377 #define STRTBLINCR (sizeof(struct strhdr)) 378 #define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1)) 379 380 static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR]; 381 382 /* 383 * Allocate space for a name. It first looks to see if it already 384 * has an appropriate sized entry, and if not allocates a new one. 385 */ 386 char * 387 savename(char *name) 388 { 389 struct strhdr *np, *tp; 390 long len, siz; 391 char *cp, *ep; 392 393 if (name == NULL) 394 panic("bad name\n"); 395 len = strlen(name); 396 tp = &strtblhdr[len / STRTBLINCR]; 397 if (tp->next == NULL) { 398 cp = malloc(pagesize); 399 if (cp == NULL) 400 panic("no space for string table\n"); 401 for (siz = allocsize(len), ep = (cp + pagesize) - siz; 402 cp <= ep; cp += siz) { 403 np = (struct strhdr *)cp; 404 np->next = tp->next; 405 tp->next = np; 406 } 407 } 408 np = tp->next; 409 tp->next = np->next; 410 cp = (char *)np; 411 (void) strcpy(cp, name); 412 return (cp); 413 } 414 415 /* 416 * Free space for a name. The resulting entry is linked onto the 417 * appropriate free list. 418 */ 419 void 420 freename(char *name) 421 { 422 struct strhdr *tp, *np; 423 424 tp = &strtblhdr[strlen(name) / STRTBLINCR]; 425 np = (struct strhdr *)name; 426 np->next = tp->next; 427 tp->next = np; 428 } 429 430 /* 431 * Useful quantities placed at the end of a dumped symbol table. 432 */ 433 struct symtableheader { 434 int32_t volno; 435 int32_t stringsize; 436 int32_t entrytblsize; 437 time_t dumptime; 438 time_t dumpdate; 439 ino_t maxino; 440 int32_t ntrec; 441 }; 442 443 /* 444 * dump a snapshot of the symbol table 445 */ 446 void 447 dumpsymtable(char *filename, int32_t checkpt) 448 { 449 struct entry *ep, *tep; 450 ino_t i; 451 struct entry temp, *tentry; 452 long mynum = 1, stroff = 0; 453 FILE *fd; 454 struct symtableheader hdr; 455 456 vprintf(stdout, "Check pointing the restore\n"); 457 if (Nflag) 458 return; 459 if ((fd = fopen(filename, "w")) == NULL) { 460 fprintf(stderr, "fopen: %s\n", strerror(errno)); 461 panic("cannot create save file %s for symbol table\n", 462 filename); 463 } 464 clearerr(fd); 465 /* 466 * Assign indicies to each entry 467 * Write out the string entries 468 */ 469 for (i = WINO; i <= maxino; i++) { 470 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) { 471 ep->e_index = mynum++; 472 (void) fwrite(ep->e_name, sizeof(char), 473 (int)allocsize(ep->e_namlen), fd); 474 } 475 } 476 /* 477 * Convert pointers to indexes, and output 478 */ 479 tep = &temp; 480 stroff = 0; 481 for (i = WINO; i <= maxino; i++) { 482 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) { 483 memmove(tep, ep, (long)sizeof(struct entry)); 484 tep->e_name = (char *)stroff; 485 stroff += allocsize(ep->e_namlen); 486 tep->e_parent = (struct entry *)(long) 487 ep->e_parent->e_index; 488 if (ep->e_links != NULL) 489 tep->e_links = (struct entry *)(long) 490 ep->e_links->e_index; 491 if (ep->e_sibling != NULL) 492 tep->e_sibling = (struct entry *)(long) 493 ep->e_sibling->e_index; 494 if (ep->e_entries != NULL) 495 tep->e_entries = (struct entry *)(long) 496 ep->e_entries->e_index; 497 if (ep->e_next != NULL) 498 tep->e_next = (struct entry *)(long) 499 ep->e_next->e_index; 500 (void) fwrite((char *)tep, sizeof(struct entry), 1, fd); 501 } 502 } 503 /* 504 * Convert entry pointers to indexes, and output 505 */ 506 for (i = 0; i < entrytblsize; i++) { 507 if (entry[i] == NULL) 508 tentry = NULL; 509 else 510 tentry = (struct entry *)(long)entry[i]->e_index; 511 (void) fwrite((char *)&tentry, sizeof(struct entry *), 1, fd); 512 } 513 hdr.volno = checkpt; 514 hdr.maxino = maxino; 515 hdr.entrytblsize = entrytblsize; 516 hdr.stringsize = stroff; 517 hdr.dumptime = dumptime; 518 hdr.dumpdate = dumpdate; 519 hdr.ntrec = ntrec; 520 (void) fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd); 521 if (ferror(fd)) { 522 fprintf(stderr, "fwrite: %s\n", strerror(errno)); 523 panic("output error to file %s writing symbol table\n", 524 filename); 525 } 526 (void) fclose(fd); 527 } 528 529 /* 530 * Initialize a symbol table from a file 531 */ 532 void 533 initsymtable(char *filename) 534 { 535 char *base; 536 long tblsize; 537 struct entry *ep; 538 struct entry *baseep, *lep; 539 struct symtableheader hdr; 540 struct stat stbuf; 541 long i; 542 int fd; 543 544 vprintf(stdout, "Initialize symbol table.\n"); 545 if (filename == NULL) { 546 entrytblsize = maxino / HASHFACTOR; 547 entry = (struct entry **) 548 calloc((unsigned)entrytblsize, sizeof(struct entry *)); 549 if (entry == (struct entry **)NULL) 550 panic("no memory for entry table\n"); 551 ep = addentry(".", ROOTINO, NODE); 552 ep->e_flags |= NEW; 553 return; 554 } 555 if ((fd = open(filename, O_RDONLY, 0)) < 0) { 556 fprintf(stderr, "open: %s\n", strerror(errno)); 557 panic("cannot open symbol table file %s\n", filename); 558 } 559 if (fstat(fd, &stbuf) < 0) { 560 fprintf(stderr, "stat: %s\n", strerror(errno)); 561 panic("cannot stat symbol table file %s\n", filename); 562 } 563 tblsize = stbuf.st_size - sizeof(struct symtableheader); 564 base = calloc((unsigned)tblsize, sizeof(char)); 565 if (base == NULL) 566 panic("cannot allocate space for symbol table\n"); 567 if (read(fd, base, (int)tblsize) < 0 || 568 read(fd, (char *)&hdr, sizeof(struct symtableheader)) < 0) { 569 fprintf(stderr, "read: %s\n", strerror(errno)); 570 panic("cannot read symbol table file %s\n", filename); 571 } 572 switch (command) { 573 case 'r': 574 /* 575 * For normal continuation, insure that we are using 576 * the next incremental tape 577 */ 578 if (hdr.dumpdate != dumptime) { 579 if (hdr.dumpdate < dumptime) 580 fprintf(stderr, "Incremental tape too low\n"); 581 else 582 fprintf(stderr, "Incremental tape too high\n"); 583 exit(1); 584 } 585 break; 586 case 'R': 587 /* 588 * For restart, insure that we are using the same tape 589 */ 590 curfile.action = SKIP; 591 dumptime = hdr.dumptime; 592 dumpdate = hdr.dumpdate; 593 if (!bflag) 594 newtapebuf(hdr.ntrec); 595 getvol(hdr.volno); 596 break; 597 default: 598 panic("initsymtable called from command %c\n", command); 599 break; 600 } 601 maxino = hdr.maxino; 602 entrytblsize = hdr.entrytblsize; 603 entry = (struct entry **) 604 (base + tblsize - (entrytblsize * sizeof(struct entry *))); 605 baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry)); 606 lep = (struct entry *)entry; 607 for (i = 0; i < entrytblsize; i++) { 608 if (entry[i] == NULL) 609 continue; 610 entry[i] = &baseep[(long)entry[i]]; 611 } 612 for (ep = &baseep[1]; ep < lep; ep++) { 613 ep->e_name = base + (long)ep->e_name; 614 ep->e_parent = &baseep[(long)ep->e_parent]; 615 if (ep->e_sibling != NULL) 616 ep->e_sibling = &baseep[(long)ep->e_sibling]; 617 if (ep->e_links != NULL) 618 ep->e_links = &baseep[(long)ep->e_links]; 619 if (ep->e_entries != NULL) 620 ep->e_entries = &baseep[(long)ep->e_entries]; 621 if (ep->e_next != NULL) 622 ep->e_next = &baseep[(long)ep->e_next]; 623 } 624 } 625