1 /*
2 * Copyright (c) 1983, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * %sccs.include.redist.c%
6 */
7
8 #ifndef lint
9 static char sccsid[] = "@(#)symtab.c 8.3 (Berkeley) 04/28/95";
10 #endif /* not lint */
11
12 /*
13 * These routines maintain the symbol table which tracks the state
14 * of the file system being restored. They provide lookup by either
15 * name or inode number. They also provide for creation, deletion,
16 * and renaming of entries. Because of the dynamic nature of pathnames,
17 * names should not be saved, but always constructed just before they
18 * are needed, by calling "myname".
19 */
20
21 #include <sys/param.h>
22 #include <sys/stat.h>
23
24 #include <ufs/ufs/dinode.h>
25
26 #include <errno.h>
27 #include <fcntl.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <unistd.h>
32
33 #include "restore.h"
34 #include "extern.h"
35
36 /*
37 * The following variables define the inode symbol table.
38 * The primary hash table is dynamically allocated based on
39 * the number of inodes in the file system (maxino), scaled by
40 * HASHFACTOR. The variable "entry" points to the hash table;
41 * the variable "entrytblsize" indicates its size (in entries).
42 */
43 #define HASHFACTOR 5
44 static struct entry **entry;
45 static long entrytblsize;
46
47 static void addino __P((ino_t, struct entry *));
48 static struct entry *lookupparent __P((char *));
49 static void removeentry __P((struct entry *));
50
51 /*
52 * Look up an entry by inode number
53 */
54 struct entry *
lookupino(inum)55 lookupino(inum)
56 ino_t inum;
57 {
58 register struct entry *ep;
59
60 if (inum < WINO || inum >= maxino)
61 return (NULL);
62 for (ep = entry[inum % entrytblsize]; ep != NULL; ep = ep->e_next)
63 if (ep->e_ino == inum)
64 return (ep);
65 return (NULL);
66 }
67
68 /*
69 * Add an entry into the entry table
70 */
71 static void
addino(inum,np)72 addino(inum, np)
73 ino_t inum;
74 struct entry *np;
75 {
76 struct entry **epp;
77
78 if (inum < WINO || inum >= maxino)
79 panic("addino: out of range %d\n", inum);
80 epp = &entry[inum % entrytblsize];
81 np->e_ino = inum;
82 np->e_next = *epp;
83 *epp = np;
84 if (dflag)
85 for (np = np->e_next; np != NULL; np = np->e_next)
86 if (np->e_ino == inum)
87 badentry(np, "duplicate inum");
88 }
89
90 /*
91 * Delete an entry from the entry table
92 */
93 void
deleteino(inum)94 deleteino(inum)
95 ino_t inum;
96 {
97 register struct entry *next;
98 struct entry **prev;
99
100 if (inum < WINO || inum >= maxino)
101 panic("deleteino: out of range %d\n", inum);
102 prev = &entry[inum % entrytblsize];
103 for (next = *prev; next != NULL; next = next->e_next) {
104 if (next->e_ino == inum) {
105 next->e_ino = 0;
106 *prev = next->e_next;
107 return;
108 }
109 prev = &next->e_next;
110 }
111 panic("deleteino: %d not found\n", inum);
112 }
113
114 /*
115 * Look up an entry by name
116 */
117 struct entry *
lookupname(name)118 lookupname(name)
119 char *name;
120 {
121 register struct entry *ep;
122 register char *np, *cp;
123 char buf[MAXPATHLEN];
124
125 cp = name;
126 for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) {
127 for (np = buf; *cp != '/' && *cp != '\0'; )
128 *np++ = *cp++;
129 *np = '\0';
130 for ( ; ep != NULL; ep = ep->e_sibling)
131 if (strcmp(ep->e_name, buf) == 0)
132 break;
133 if (ep == NULL)
134 break;
135 if (*cp++ == '\0')
136 return (ep);
137 }
138 return (NULL);
139 }
140
141 /*
142 * Look up the parent of a pathname
143 */
144 static struct entry *
lookupparent(name)145 lookupparent(name)
146 char *name;
147 {
148 struct entry *ep;
149 char *tailindex;
150
151 tailindex = strrchr(name, '/');
152 if (tailindex == NULL)
153 return (NULL);
154 *tailindex = '\0';
155 ep = lookupname(name);
156 *tailindex = '/';
157 if (ep == NULL)
158 return (NULL);
159 if (ep->e_type != NODE)
160 panic("%s is not a directory\n", name);
161 return (ep);
162 }
163
164 /*
165 * Determine the current pathname of a node or leaf
166 */
167 char *
myname(ep)168 myname(ep)
169 register struct entry *ep;
170 {
171 register char *cp;
172 static char namebuf[MAXPATHLEN];
173
174 for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) {
175 cp -= ep->e_namlen;
176 memmove(cp, ep->e_name, (long)ep->e_namlen);
177 if (ep == lookupino(ROOTINO))
178 return (cp);
179 *(--cp) = '/';
180 ep = ep->e_parent;
181 }
182 panic("%s: pathname too long\n", cp);
183 return(cp);
184 }
185
186 /*
187 * Unused symbol table entries are linked together on a freelist
188 * headed by the following pointer.
189 */
190 static struct entry *freelist = NULL;
191
192 /*
193 * add an entry to the symbol table
194 */
195 struct entry *
addentry(name,inum,type)196 addentry(name, inum, type)
197 char *name;
198 ino_t inum;
199 int type;
200 {
201 register struct entry *np, *ep;
202
203 if (freelist != NULL) {
204 np = freelist;
205 freelist = np->e_next;
206 memset(np, 0, (long)sizeof(struct entry));
207 } else {
208 np = (struct entry *)calloc(1, sizeof(struct entry));
209 if (np == NULL)
210 panic("no memory to extend symbol table\n");
211 }
212 np->e_type = type & ~LINK;
213 ep = lookupparent(name);
214 if (ep == NULL) {
215 if (inum != ROOTINO || lookupino(ROOTINO) != NULL)
216 panic("bad name to addentry %s\n", name);
217 np->e_name = savename(name);
218 np->e_namlen = strlen(name);
219 np->e_parent = np;
220 addino(ROOTINO, np);
221 return (np);
222 }
223 np->e_name = savename(strrchr(name, '/') + 1);
224 np->e_namlen = strlen(np->e_name);
225 np->e_parent = ep;
226 np->e_sibling = ep->e_entries;
227 ep->e_entries = np;
228 if (type & LINK) {
229 ep = lookupino(inum);
230 if (ep == NULL)
231 panic("link to non-existant name\n");
232 np->e_ino = inum;
233 np->e_links = ep->e_links;
234 ep->e_links = np;
235 } else if (inum != 0) {
236 if (lookupino(inum) != NULL)
237 panic("duplicate entry\n");
238 addino(inum, np);
239 }
240 return (np);
241 }
242
243 /*
244 * delete an entry from the symbol table
245 */
246 void
freeentry(ep)247 freeentry(ep)
248 register struct entry *ep;
249 {
250 register struct entry *np;
251 ino_t inum;
252
253 if (ep->e_flags != REMOVED)
254 badentry(ep, "not marked REMOVED");
255 if (ep->e_type == NODE) {
256 if (ep->e_links != NULL)
257 badentry(ep, "freeing referenced directory");
258 if (ep->e_entries != NULL)
259 badentry(ep, "freeing non-empty directory");
260 }
261 if (ep->e_ino != 0) {
262 np = lookupino(ep->e_ino);
263 if (np == NULL)
264 badentry(ep, "lookupino failed");
265 if (np == ep) {
266 inum = ep->e_ino;
267 deleteino(inum);
268 if (ep->e_links != NULL)
269 addino(inum, ep->e_links);
270 } else {
271 for (; np != NULL; np = np->e_links) {
272 if (np->e_links == ep) {
273 np->e_links = ep->e_links;
274 break;
275 }
276 }
277 if (np == NULL)
278 badentry(ep, "link not found");
279 }
280 }
281 removeentry(ep);
282 freename(ep->e_name);
283 ep->e_next = freelist;
284 freelist = ep;
285 }
286
287 /*
288 * Relocate an entry in the tree structure
289 */
290 void
moveentry(ep,newname)291 moveentry(ep, newname)
292 register struct entry *ep;
293 char *newname;
294 {
295 struct entry *np;
296 char *cp;
297
298 np = lookupparent(newname);
299 if (np == NULL)
300 badentry(ep, "cannot move ROOT");
301 if (np != ep->e_parent) {
302 removeentry(ep);
303 ep->e_parent = np;
304 ep->e_sibling = np->e_entries;
305 np->e_entries = ep;
306 }
307 cp = strrchr(newname, '/') + 1;
308 freename(ep->e_name);
309 ep->e_name = savename(cp);
310 ep->e_namlen = strlen(cp);
311 if (strcmp(gentempname(ep), ep->e_name) == 0)
312 ep->e_flags |= TMPNAME;
313 else
314 ep->e_flags &= ~TMPNAME;
315 }
316
317 /*
318 * Remove an entry in the tree structure
319 */
320 static void
removeentry(ep)321 removeentry(ep)
322 register struct entry *ep;
323 {
324 register struct entry *np;
325
326 np = ep->e_parent;
327 if (np->e_entries == ep) {
328 np->e_entries = ep->e_sibling;
329 } else {
330 for (np = np->e_entries; np != NULL; np = np->e_sibling) {
331 if (np->e_sibling == ep) {
332 np->e_sibling = ep->e_sibling;
333 break;
334 }
335 }
336 if (np == NULL)
337 badentry(ep, "cannot find entry in parent list");
338 }
339 }
340
341 /*
342 * Table of unused string entries, sorted by length.
343 *
344 * Entries are allocated in STRTBLINCR sized pieces so that names
345 * of similar lengths can use the same entry. The value of STRTBLINCR
346 * is chosen so that every entry has at least enough space to hold
347 * a "struct strtbl" header. Thus every entry can be linked onto an
348 * apprpriate free list.
349 *
350 * NB. The macro "allocsize" below assumes that "struct strhdr"
351 * has a size that is a power of two.
352 */
353 struct strhdr {
354 struct strhdr *next;
355 };
356
357 #define STRTBLINCR (sizeof(struct strhdr))
358 #define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1))
359
360 static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR];
361
362 /*
363 * Allocate space for a name. It first looks to see if it already
364 * has an appropriate sized entry, and if not allocates a new one.
365 */
366 char *
savename(name)367 savename(name)
368 char *name;
369 {
370 struct strhdr *np;
371 long len;
372 char *cp;
373
374 if (name == NULL)
375 panic("bad name\n");
376 len = strlen(name);
377 np = strtblhdr[len / STRTBLINCR].next;
378 if (np != NULL) {
379 strtblhdr[len / STRTBLINCR].next = np->next;
380 cp = (char *)np;
381 } else {
382 cp = malloc((unsigned)allocsize(len));
383 if (cp == NULL)
384 panic("no space for string table\n");
385 }
386 (void) strcpy(cp, name);
387 return (cp);
388 }
389
390 /*
391 * Free space for a name. The resulting entry is linked onto the
392 * appropriate free list.
393 */
394 void
freename(name)395 freename(name)
396 char *name;
397 {
398 struct strhdr *tp, *np;
399
400 tp = &strtblhdr[strlen(name) / STRTBLINCR];
401 np = (struct strhdr *)name;
402 np->next = tp->next;
403 tp->next = np;
404 }
405
406 /*
407 * Useful quantities placed at the end of a dumped symbol table.
408 */
409 struct symtableheader {
410 long volno;
411 long stringsize;
412 long entrytblsize;
413 time_t dumptime;
414 time_t dumpdate;
415 ino_t maxino;
416 long ntrec;
417 };
418
419 /*
420 * dump a snapshot of the symbol table
421 */
422 void
dumpsymtable(filename,checkpt)423 dumpsymtable(filename, checkpt)
424 char *filename;
425 long checkpt;
426 {
427 register struct entry *ep, *tep;
428 register ino_t i;
429 struct entry temp, *tentry;
430 long mynum = 1, stroff = 0;
431 FILE *fd;
432 struct symtableheader hdr;
433
434 vprintf(stdout, "Check pointing the restore\n");
435 if (Nflag)
436 return;
437 if ((fd = fopen(filename, "w")) == NULL) {
438 fprintf(stderr, "fopen: %s\n", strerror(errno));
439 panic("cannot create save file %s for symbol table\n",
440 filename);
441 }
442 clearerr(fd);
443 /*
444 * Assign indicies to each entry
445 * Write out the string entries
446 */
447 for (i = WINO; i <= maxino; i++) {
448 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
449 ep->e_index = mynum++;
450 (void) fwrite(ep->e_name, sizeof(char),
451 (int)allocsize(ep->e_namlen), fd);
452 }
453 }
454 /*
455 * Convert pointers to indexes, and output
456 */
457 tep = &temp;
458 stroff = 0;
459 for (i = WINO; i <= maxino; i++) {
460 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
461 memmove(tep, ep, (long)sizeof(struct entry));
462 tep->e_name = (char *)stroff;
463 stroff += allocsize(ep->e_namlen);
464 tep->e_parent = (struct entry *)ep->e_parent->e_index;
465 if (ep->e_links != NULL)
466 tep->e_links =
467 (struct entry *)ep->e_links->e_index;
468 if (ep->e_sibling != NULL)
469 tep->e_sibling =
470 (struct entry *)ep->e_sibling->e_index;
471 if (ep->e_entries != NULL)
472 tep->e_entries =
473 (struct entry *)ep->e_entries->e_index;
474 if (ep->e_next != NULL)
475 tep->e_next =
476 (struct entry *)ep->e_next->e_index;
477 (void) fwrite((char *)tep, sizeof(struct entry), 1, fd);
478 }
479 }
480 /*
481 * Convert entry pointers to indexes, and output
482 */
483 for (i = 0; i < entrytblsize; i++) {
484 if (entry[i] == NULL)
485 tentry = NULL;
486 else
487 tentry = (struct entry *)entry[i]->e_index;
488 (void) fwrite((char *)&tentry, sizeof(struct entry *), 1, fd);
489 }
490 hdr.volno = checkpt;
491 hdr.maxino = maxino;
492 hdr.entrytblsize = entrytblsize;
493 hdr.stringsize = stroff;
494 hdr.dumptime = dumptime;
495 hdr.dumpdate = dumpdate;
496 hdr.ntrec = ntrec;
497 (void) fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd);
498 if (ferror(fd)) {
499 fprintf(stderr, "fwrite: %s\n", strerror(errno));
500 panic("output error to file %s writing symbol table\n",
501 filename);
502 }
503 (void) fclose(fd);
504 }
505
506 /*
507 * Initialize a symbol table from a file
508 */
509 void
initsymtable(filename)510 initsymtable(filename)
511 char *filename;
512 {
513 char *base;
514 long tblsize;
515 register struct entry *ep;
516 struct entry *baseep, *lep;
517 struct symtableheader hdr;
518 struct stat stbuf;
519 register long i;
520 int fd;
521
522 vprintf(stdout, "Initialize symbol table.\n");
523 if (filename == NULL) {
524 entrytblsize = maxino / HASHFACTOR;
525 entry = (struct entry **)
526 calloc((unsigned)entrytblsize, sizeof(struct entry *));
527 if (entry == (struct entry **)NULL)
528 panic("no memory for entry table\n");
529 ep = addentry(".", ROOTINO, NODE);
530 ep->e_flags |= NEW;
531 return;
532 }
533 if ((fd = open(filename, O_RDONLY, 0)) < 0) {
534 fprintf(stderr, "open: %s\n", strerror(errno));
535 panic("cannot open symbol table file %s\n", filename);
536 }
537 if (fstat(fd, &stbuf) < 0) {
538 fprintf(stderr, "stat: %s\n", strerror(errno));
539 panic("cannot stat symbol table file %s\n", filename);
540 }
541 tblsize = stbuf.st_size - sizeof(struct symtableheader);
542 base = calloc(sizeof(char), (unsigned)tblsize);
543 if (base == NULL)
544 panic("cannot allocate space for symbol table\n");
545 if (read(fd, base, (int)tblsize) < 0 ||
546 read(fd, (char *)&hdr, sizeof(struct symtableheader)) < 0) {
547 fprintf(stderr, "read: %s\n", strerror(errno));
548 panic("cannot read symbol table file %s\n", filename);
549 }
550 switch (command) {
551 case 'r':
552 /*
553 * For normal continuation, insure that we are using
554 * the next incremental tape
555 */
556 if (hdr.dumpdate != dumptime) {
557 if (hdr.dumpdate < dumptime)
558 fprintf(stderr, "Incremental tape too low\n");
559 else
560 fprintf(stderr, "Incremental tape too high\n");
561 done(1);
562 }
563 break;
564 case 'R':
565 /*
566 * For restart, insure that we are using the same tape
567 */
568 curfile.action = SKIP;
569 dumptime = hdr.dumptime;
570 dumpdate = hdr.dumpdate;
571 if (!bflag)
572 newtapebuf(hdr.ntrec);
573 getvol(hdr.volno);
574 break;
575 default:
576 panic("initsymtable called from command %c\n", command);
577 break;
578 }
579 maxino = hdr.maxino;
580 entrytblsize = hdr.entrytblsize;
581 entry = (struct entry **)
582 (base + tblsize - (entrytblsize * sizeof(struct entry *)));
583 baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry));
584 lep = (struct entry *)entry;
585 for (i = 0; i < entrytblsize; i++) {
586 if (entry[i] == NULL)
587 continue;
588 entry[i] = &baseep[(long)entry[i]];
589 }
590 for (ep = &baseep[1]; ep < lep; ep++) {
591 ep->e_name = base + (long)ep->e_name;
592 ep->e_parent = &baseep[(long)ep->e_parent];
593 if (ep->e_sibling != NULL)
594 ep->e_sibling = &baseep[(long)ep->e_sibling];
595 if (ep->e_links != NULL)
596 ep->e_links = &baseep[(long)ep->e_links];
597 if (ep->e_entries != NULL)
598 ep->e_entries = &baseep[(long)ep->e_entries];
599 if (ep->e_next != NULL)
600 ep->e_next = &baseep[(long)ep->e_next];
601 }
602 }
603