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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#)symtab.c 8.3 (Berkeley) 4/28/95
  34  * $FreeBSD: src/sbin/restore/symtab.c,v 1.7.2.1 2001/12/19 14:54:14 tobez Exp $
  35  * $DragonFly: src/sbin/restore/symtab.c,v 1.8 2005/11/06 12:49:25 swildner Exp $
  36  */
  37
  38 /*
  39  * These routines maintain the symbol table which tracks the state
  40  * of the file system being restored. They provide lookup by either
  41  * name or inode number. They also provide for creation, deletion,
  42  * and renaming of entries. Because of the dynamic nature of pathnames,
  43  * names should not be saved, but always constructed just before they
  44  * are needed, by calling "myname".
  45  */
  46
  47 #include <sys/param.h>
  48 #include <sys/stat.h>
  49
  50 #include <vfs/ufs/dinode.h>
  51
  52 #include <errno.h>
  53 #include <fcntl.h>
  54 #include <stdio.h>
  55 #include <stdlib.h>
  56 #include <string.h>
  57 #include <unistd.h>
  58
  59 #include "restore.h"
  60 #include "extern.h"
  61
  62 /*
  63  * The following variables define the inode symbol table.
  64  * The primary hash table is dynamically allocated based on
  65  * the number of inodes in the file system (maxino), scaled by
  66  * HASHFACTOR. The variable "entry" points to the hash table;
  67  * the variable "entrytblsize" indicates its size (in entries).
  68  */
  69 #define HASHFACTOR 5
  70 static struct entry **entry;
  71 static long entrytblsize;
  72
  73 static void              addino(ufs1_ino_t, struct entry *);
  74 static struct entry     *lookupparent(char *);
  75 static void              removeentry(struct entry *);
  76
  77 /*
  78  * Look up an entry by inode number
  79  */
  80 struct entry *
  81 lookupino(ufs1_ino_t inum)
  82 {
  83         struct entry *ep;
  84
  85         if (inum < WINO || inum >= maxino)
  86                 return (NULL);
  87         for (ep = entry[inum % entrytblsize]; ep != NULL; ep = ep->e_next)
  88                 if (ep->e_ino == inum)
  89                         return (ep);
  90         return (NULL);
  91 }
  92
  93 /*
  94  * Add an entry into the entry table
  95  */
  96 static void
  97 addino(ufs1_ino_t inum, struct entry *np)
  98 {
  99         struct entry **epp;
 100
 101         if (inum < WINO || inum >= maxino)
 102                 panic("addino: out of range %d\n", inum);
 103         epp = &entry[inum % entrytblsize];
 104         np->e_ino = inum;
 105         np->e_next = *epp;
 106         *epp = np;
 107         if (dflag)
 108                 for (np = np->e_next; np != NULL; np = np->e_next)
 109                         if (np->e_ino == inum)
 110                                 badentry(np, "duplicate inum");
 111 }
 112
 113 /*
 114  * Delete an entry from the entry table
 115  */
 116 void
 117 deleteino(ufs1_ino_t inum)
 118 {
 119         struct entry *next;
 120         struct entry **prev;
 121
 122         if (inum < WINO || inum >= maxino)
 123                 panic("deleteino: out of range %d\n", inum);
 124         prev = &entry[inum % entrytblsize];
 125         for (next = *prev; next != NULL; next = next->e_next) {
 126                 if (next->e_ino == inum) {
 127                         next->e_ino = 0;
 128                         *prev = next->e_next;
 129                         return;
 130                 }
 131                 prev = &next->e_next;
 132         }
 133         panic("deleteino: %d not found\n", inum);
 134 }
 135
 136 /*
 137  * Look up an entry by name
 138  */
 139 struct entry *
 140 lookupname(char *name)
 141 {
 142         struct entry *ep;
 143         char *np, *cp;
 144         char buf[MAXPATHLEN];
 145
 146         cp = name;
 147         for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) {
 148                 for (np = buf; *cp != '/' && *cp != '\0' &&
 149                                 np < &buf[sizeof(buf)]; )
 150                         *np++ = *cp++;
 151                 if (np == &buf[sizeof(buf)])
 152                         break;
 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 free list
 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, ufs1_ino_t inum, int type)
 219 {
 220         struct entry *np, *ep;
 221
 222         if (freelist != NULL) {
 223                 np = freelist;
 224                 freelist = np->e_next;
 225                 memset(np, 0, (long)sizeof(struct entry));
 226         } else {
 227                 np = (struct entry *)calloc(1, sizeof(struct entry));
 228                 if (np == NULL)
 229                         panic("no memory to extend symbol table\n");
 230         }
 231         np->e_type = type & ~LINK;
 232         ep = lookupparent(name);
 233         if (ep == NULL) {
 234                 if (inum != ROOTINO || lookupino(ROOTINO) != NULL)
 235                         panic("bad name to addentry %s\n", name);
 236                 np->e_name = savename(name);
 237                 np->e_namlen = strlen(name);
 238                 np->e_parent = np;
 239                 addino(ROOTINO, np);
 240                 return (np);
 241         }
 242         np->e_name = savename(strrchr(name, '/') + 1);
 243         np->e_namlen = strlen(np->e_name);
 244         np->e_parent = ep;
 245         np->e_sibling = ep->e_entries;
 246         ep->e_entries = np;
 247         if (type & LINK) {
 248                 ep = lookupino(inum);
 249                 if (ep == NULL)
 250                         panic("link to non-existent name\n");
 251                 np->e_ino = inum;
 252                 np->e_links = ep->e_links;
 253                 ep->e_links = np;
 254         } else if (inum != 0) {
 255                 if (lookupino(inum) != NULL)
 256                         panic("duplicate entry\n");
 257                 addino(inum, np);
 258         }
 259         return (np);
 260 }
 261
 262 /*
 263  * delete an entry from the symbol table
 264  */
 265 void
 266 freeentry(struct entry *ep)
 267 {
 268         struct entry *np;
 269         ufs1_ino_t inum;
 270
 271         if (ep->e_flags != REMOVED)
 272                 badentry(ep, "not marked REMOVED");
 273         if (ep->e_type == NODE) {
 274                 if (ep->e_links != NULL)
 275                         badentry(ep, "freeing referenced directory");
 276                 if (ep->e_entries != NULL)
 277                         badentry(ep, "freeing non-empty directory");
 278         }
 279         if (ep->e_ino != 0) {
 280                 np = lookupino(ep->e_ino);
 281                 if (np == NULL)
 282                         badentry(ep, "lookupino failed");
 283                 if (np == ep) {
 284                         inum = ep->e_ino;
 285                         deleteino(inum);
 286                         if (ep->e_links != NULL)
 287                                 addino(inum, ep->e_links);
 288                 } else {
 289                         for (; np != NULL; np = np->e_links) {
 290                                 if (np->e_links == ep) {
 291                                         np->e_links = ep->e_links;
 292                                         break;
 293                                 }
 294                         }
 295                         if (np == NULL)
 296                                 badentry(ep, "link not found");
 297                 }
 298         }
 299         removeentry(ep);
 300         freename(ep->e_name);
 301         ep->e_next = freelist;
 302         freelist = ep;
 303 }
 304
 305 /*
 306  * Relocate an entry in the tree structure
 307  */
 308 void
 309 moveentry(struct entry *ep, char *newname)
 310 {
 311         struct entry *np;
 312         char *cp;
 313
 314         np = lookupparent(newname);
 315         if (np == NULL)
 316                 badentry(ep, "cannot move ROOT");
 317         if (np != ep->e_parent) {
 318                 removeentry(ep);
 319                 ep->e_parent = np;
 320                 ep->e_sibling = np->e_entries;
 321                 np->e_entries = ep;
 322         }
 323         cp = strrchr(newname, '/') + 1;
 324         freename(ep->e_name);
 325         ep->e_name = savename(cp);
 326         ep->e_namlen = strlen(cp);
 327         if (strcmp(gentempname(ep), ep->e_name) == 0)
 328                 ep->e_flags |= TMPNAME;
 329         else
 330                 ep->e_flags &= ~TMPNAME;
 331 }
 332
 333 /*
 334  * Remove an entry in the tree structure
 335  */
 336 static void
 337 removeentry(struct entry *ep)
 338 {
 339         struct entry *np;
 340
 341         np = ep->e_parent;
 342         if (np->e_entries == ep) {
 343                 np->e_entries = ep->e_sibling;
 344         } else {
 345                 for (np = np->e_entries; np != NULL; np = np->e_sibling) {
 346                         if (np->e_sibling == ep) {
 347                                 np->e_sibling = ep->e_sibling;
 348                                 break;
 349                         }
 350                 }
 351                 if (np == NULL)
 352                         badentry(ep, "cannot find entry in parent list");
 353         }
 354 }
 355
 356 /*
 357  * Table of unused string entries, sorted by length.
 358  *
 359  * Entries are allocated in STRTBLINCR sized pieces so that names
 360  * of similar lengths can use the same entry. The value of STRTBLINCR
 361  * is chosen so that every entry has at least enough space to hold
 362  * a "struct strtbl" header. Thus every entry can be linked onto an
 363  * appropriate free list.
 364  *
 365  * NB. The macro "allocsize" below assumes that "struct strhdr"
 366  *     has a size that is a power of two.
 367  */
 368 struct strhdr {
 369         struct strhdr *next;
 370 };
 371
 372 #define STRTBLINCR      (sizeof(struct strhdr))
 373 #define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1))
 374
 375 static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR];
 376
 377 /*
 378  * Allocate space for a name. It first looks to see if it already
 379  * has an appropriate sized entry, and if not allocates a new one.
 380  */
 381 char *
 382 savename(char *name)
 383 {
 384         struct strhdr *np;
 385         long len;
 386         char *cp;
 387
 388         if (name == NULL)
 389                 panic("bad name\n");
 390         len = strlen(name);
 391         np = strtblhdr[len / STRTBLINCR].next;
 392         if (np != NULL) {
 393                 strtblhdr[len / STRTBLINCR].next = np->next;
 394                 cp = (char *)np;
 395         } else {
 396                 cp = malloc((unsigned)allocsize(len));
 397                 if (cp == NULL)
 398                         panic("no space for string table\n");
 399         }
 400         strcpy(cp, name);
 401         return (cp);
 402 }
 403
 404 /*
 405  * Free space for a name. The resulting entry is linked onto the
 406  * appropriate free list.
 407  */
 408 void
 409 freename(char *name)
 410 {
 411         struct strhdr *tp, *np;
 412
 413         tp = &strtblhdr[strlen(name) / STRTBLINCR];
 414         np = (struct strhdr *)name;
 415         np->next = tp->next;
 416         tp->next = np;
 417 }
 418
 419 /*
 420  * Useful quantities placed at the end of a dumped symbol table.
 421  */
 422 struct symtableheader {
 423         int32_t volno;
 424         int32_t stringsize;
 425         int32_t entrytblsize;
 426         time_t  dumptime;
 427         time_t  dumpdate;
 428         ufs1_ino_t maxino;
 429         int32_t ntrec;
 430 };
 431
 432 /*
 433  * dump a snapshot of the symbol table
 434  */
 435 void
 436 dumpsymtable(char *filename, long checkpt)
 437 {
 438         struct entry *ep, *tep;
 439         ufs1_ino_t i;
 440         struct entry temp, *tentry;
 441         long mynum = 1, stroff = 0;
 442         FILE *fd;
 443         struct symtableheader hdr;
 444
 445         vprintf(stdout, "Check pointing the restore\n");
 446         if (Nflag)
 447                 return;
 448         if ((fd = fopen(filename, "w")) == NULL) {
 449                 fprintf(stderr, "fopen: %s\n", strerror(errno));
 450                 panic("cannot create save file %s for symbol table\n",
 451                         filename);
 452                 done(1);
 453         }
 454         clearerr(fd);
 455         /*
 456          * Assign indices to each entry
 457          * Write out the string entries
 458          */
 459         for (i = WINO; i <= maxino; i++) {
 460                 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
 461                         ep->e_index = mynum++;
 462                         fwrite(ep->e_name, sizeof(char),
 463                                (int)allocsize(ep->e_namlen), fd);
 464                 }
 465         }
 466         /*
 467          * Convert pointers to indexes, and output
 468          */
 469         tep = &temp;
 470         stroff = 0;
 471         for (i = WINO; i <= maxino; i++) {
 472                 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
 473                         memmove(tep, ep, (long)sizeof(struct entry));
 474                         tep->e_name = (char *)stroff;
 475                         stroff += allocsize(ep->e_namlen);
 476                         tep->e_parent = (struct entry *)ep->e_parent->e_index;
 477                         if (ep->e_links != NULL)
 478                                 tep->e_links =
 479                                         (struct entry *)ep->e_links->e_index;
 480                         if (ep->e_sibling != NULL)
 481                                 tep->e_sibling =
 482                                         (struct entry *)ep->e_sibling->e_index;
 483                         if (ep->e_entries != NULL)
 484                                 tep->e_entries =
 485                                         (struct entry *)ep->e_entries->e_index;
 486                         if (ep->e_next != NULL)
 487                                 tep->e_next =
 488                                         (struct entry *)ep->e_next->e_index;
 489                         fwrite((char *)tep, sizeof(struct entry), 1, fd);
 490                 }
 491         }
 492         /*
 493          * Convert entry pointers to indexes, and output
 494          */
 495         for (i = 0; i < entrytblsize; i++) {
 496                 if (entry[i] == NULL)
 497                         tentry = NULL;
 498                 else
 499                         tentry = (struct entry *)entry[i]->e_index;
 500                 fwrite((char *)&tentry, sizeof(struct entry *), 1, fd);
 501         }
 502         hdr.volno = checkpt;
 503         hdr.maxino = maxino;
 504         hdr.entrytblsize = entrytblsize;
 505         hdr.stringsize = stroff;
 506         hdr.dumptime = dumptime;
 507         hdr.dumpdate = dumpdate;
 508         hdr.ntrec = ntrec;
 509         fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd);
 510         if (ferror(fd)) {
 511                 fprintf(stderr, "fwrite: %s\n", strerror(errno));
 512                 panic("output error to file %s writing symbol table\n",
 513                         filename);
 514         }
 515         fclose(fd);
 516 }
 517
 518 /*
 519  * Initialize a symbol table from a file
 520  */
 521 void
 522 initsymtable(char *filename)
 523 {
 524         char *base;
 525         long tblsize;
 526         struct entry *ep;
 527         struct entry *baseep, *lep;
 528         struct symtableheader hdr;
 529         struct stat stbuf;
 530         long i;
 531         int fd;
 532
 533         vprintf(stdout, "Initialize symbol table.\n");
 534         if (filename == NULL) {
 535                 entrytblsize = maxino / HASHFACTOR;
 536                 entry = (struct entry **)
 537                         calloc((unsigned)entrytblsize, sizeof(struct entry *));
 538                 if (entry == (struct entry **)NULL)
 539                         panic("no memory for entry table\n");
 540                 ep = addentry(".", ROOTINO, NODE);
 541                 ep->e_flags |= NEW;
 542                 return;
 543         }
 544         if ((fd = open(filename, O_RDONLY, 0)) < 0) {
 545                 fprintf(stderr, "open: %s\n", strerror(errno));
 546                 panic("cannot open symbol table file %s\n", filename);
 547         }
 548         if (fstat(fd, &stbuf) < 0) {
 549                 fprintf(stderr, "stat: %s\n", strerror(errno));
 550                 panic("cannot stat symbol table file %s\n", filename);
 551         }
 552         tblsize = stbuf.st_size - sizeof(struct symtableheader);
 553         base = calloc(sizeof(char), (unsigned)tblsize);
 554         if (base == NULL)
 555                 panic("cannot allocate space for symbol table\n");
 556         if (read(fd, base, (int)tblsize) < 0 ||
 557             read(fd, (char *)&hdr, sizeof(struct symtableheader)) < 0) {
 558                 fprintf(stderr, "read: %s\n", strerror(errno));
 559                 panic("cannot read symbol table file %s\n", filename);
 560         }
 561         switch (command) {
 562         case 'r':
 563                 /*
 564                  * For normal continuation, insure that we are using
 565                  * the next incremental tape
 566                  */
 567                 if (hdr.dumpdate != dumptime) {
 568                         if (hdr.dumpdate < dumptime)
 569                                 fprintf(stderr, "Incremental tape too low\n");
 570                         else
 571                                 fprintf(stderr, "Incremental tape too high\n");
 572                         done(1);
 573                 }
 574                 break;
 575         case 'R':
 576                 /*
 577                  * For restart, insure that we are using the same tape
 578                  */
 579                 curfile.action = SKIP;
 580                 dumptime = hdr.dumptime;
 581                 dumpdate = hdr.dumpdate;
 582                 if (!bflag)
 583                         newtapebuf(hdr.ntrec);
 584                 getvol(hdr.volno);
 585                 break;
 586         default:
 587                 panic("initsymtable called from command %c\n", command);
 588                 break;
 589         }
 590         maxino = hdr.maxino;
 591         entrytblsize = hdr.entrytblsize;
 592         entry = (struct entry **)
 593                 (base + tblsize - (entrytblsize * sizeof(struct entry *)));
 594         baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry));
 595         lep = (struct entry *)entry;
 596         for (i = 0; i < entrytblsize; i++) {
 597                 if (entry[i] == NULL)
 598                         continue;
 599                 entry[i] = &baseep[(long)entry[i]];
 600         }
 601         for (ep = &baseep[1]; ep < lep; ep++) {
 602                 ep->e_name = base + (long)ep->e_name;
 603                 ep->e_parent = &baseep[(long)ep->e_parent];
 604                 if (ep->e_sibling != NULL)
 605                         ep->e_sibling = &baseep[(long)ep->e_sibling];
 606                 if (ep->e_links != NULL)
 607                         ep->e_links = &baseep[(long)ep->e_links];
 608                 if (ep->e_entries != NULL)
 609                         ep->e_entries = &baseep[(long)ep->e_entries];
 610                 if (ep->e_next != NULL)
 611                         ep->e_next = &baseep[(long)ep->e_next];
 612         }
 613 }