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29 * @(#)symtab.c 8.3 (Berkeley) 4/28/95
30 * $FreeBSD: src/sbin/restore/symtab.c,v 1.7.2.1 2001/12/19 14:54:14 tobez Exp $
31 * $DragonFly: src/sbin/restore/symtab.c,v 1.8 2005/11/06 12:49:25 swildner Exp $
35 * These routines maintain the symbol table which tracks the state
36 * of the file system being restored. They provide lookup by either
37 * name or inode number. They also provide for creation, deletion,
38 * and renaming of entries. Because of the dynamic nature of pathnames,
39 * names should not be saved, but always constructed just before they
40 * are needed, by calling "myname".
43 #include <sys/param.h>
46 #include <vfs/ufs/dinode.h>
59 * The following variables define the inode symbol table.
60 * The primary hash table is dynamically allocated based on
61 * the number of inodes in the file system (maxino), scaled by
62 * HASHFACTOR. The variable "entry" points to the hash table;
63 * the variable "entrytblsize" indicates its size (in entries).
66 static struct entry **entry;
67 static long entrytblsize;
69 static void addino(ufs1_ino_t, struct entry *);
70 static struct entry *lookupparent(char *);
71 static void removeentry(struct entry *);
74 * Look up an entry by inode number
77 lookupino(ufs1_ino_t inum)
81 if (inum < WINO || inum >= maxino)
83 for (ep = entry[inum % entrytblsize]; ep != NULL; ep = ep->e_next)
84 if (ep->e_ino == inum)
90 * Add an entry into the entry table
93 addino(ufs1_ino_t inum, struct entry *np)
97 if (inum < WINO || inum >= maxino)
98 panic("addino: out of range %d\n", inum);
99 epp = &entry[inum % entrytblsize];
104 for (np = np->e_next; np != NULL; np = np->e_next)
105 if (np->e_ino == inum)
106 badentry(np, "duplicate inum");
110 * Delete an entry from the entry table
113 deleteino(ufs1_ino_t inum)
118 if (inum < WINO || inum >= maxino)
119 panic("deleteino: out of range %d\n", inum);
120 prev = &entry[inum % entrytblsize];
121 for (next = *prev; next != NULL; next = next->e_next) {
122 if (next->e_ino == inum) {
124 *prev = next->e_next;
127 prev = &next->e_next;
129 panic("deleteino: %d not found\n", inum);
133 * Look up an entry by name
136 lookupname(char *name)
140 char buf[MAXPATHLEN];
143 for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) {
144 for (np = buf; *cp != '/' && *cp != '\0' &&
145 np < &buf[sizeof(buf)]; )
147 if (np == &buf[sizeof(buf)])
150 for ( ; ep != NULL; ep = ep->e_sibling)
151 if (strcmp(ep->e_name, buf) == 0)
162 * Look up the parent of a pathname
164 static struct entry *
165 lookupparent(char *name)
170 tailindex = strrchr(name, '/');
171 if (tailindex == NULL)
174 ep = lookupname(name);
178 if (ep->e_type != NODE)
179 panic("%s is not a directory\n", name);
184 * Determine the current pathname of a node or leaf
187 myname(struct entry *ep)
190 static char namebuf[MAXPATHLEN];
192 for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) {
194 memmove(cp, ep->e_name, (long)ep->e_namlen);
195 if (ep == lookupino(ROOTINO))
200 panic("%s: pathname too long\n", cp);
205 * Unused symbol table entries are linked together on a free list
206 * headed by the following pointer.
208 static struct entry *freelist = NULL;
211 * add an entry to the symbol table
214 addentry(char *name, ufs1_ino_t inum, int type)
216 struct entry *np, *ep;
218 if (freelist != NULL) {
220 freelist = np->e_next;
221 memset(np, 0, (long)sizeof(struct entry));
223 np = (struct entry *)calloc(1, sizeof(struct entry));
225 panic("no memory to extend symbol table\n");
227 np->e_type = type & ~LINK;
228 ep = lookupparent(name);
230 if (inum != ROOTINO || lookupino(ROOTINO) != NULL)
231 panic("bad name to addentry %s\n", name);
232 np->e_name = savename(name);
233 np->e_namlen = strlen(name);
238 np->e_name = savename(strrchr(name, '/') + 1);
239 np->e_namlen = strlen(np->e_name);
241 np->e_sibling = ep->e_entries;
244 ep = lookupino(inum);
246 panic("link to non-existent name\n");
248 np->e_links = ep->e_links;
250 } else if (inum != 0) {
251 if (lookupino(inum) != NULL)
252 panic("duplicate entry\n");
259 * delete an entry from the symbol table
262 freeentry(struct entry *ep)
267 if (ep->e_flags != REMOVED)
268 badentry(ep, "not marked REMOVED");
269 if (ep->e_type == NODE) {
270 if (ep->e_links != NULL)
271 badentry(ep, "freeing referenced directory");
272 if (ep->e_entries != NULL)
273 badentry(ep, "freeing non-empty directory");
275 if (ep->e_ino != 0) {
276 np = lookupino(ep->e_ino);
278 badentry(ep, "lookupino failed");
282 if (ep->e_links != NULL)
283 addino(inum, ep->e_links);
285 for (; np != NULL; np = np->e_links) {
286 if (np->e_links == ep) {
287 np->e_links = ep->e_links;
292 badentry(ep, "link not found");
296 freename(ep->e_name);
297 ep->e_next = freelist;
302 * Relocate an entry in the tree structure
305 moveentry(struct entry *ep, char *newname)
310 np = lookupparent(newname);
312 badentry(ep, "cannot move ROOT");
313 if (np != ep->e_parent) {
316 ep->e_sibling = np->e_entries;
319 cp = strrchr(newname, '/') + 1;
320 freename(ep->e_name);
321 ep->e_name = savename(cp);
322 ep->e_namlen = strlen(cp);
323 if (strcmp(gentempname(ep), ep->e_name) == 0)
324 ep->e_flags |= TMPNAME;
326 ep->e_flags &= ~TMPNAME;
330 * Remove an entry in the tree structure
333 removeentry(struct entry *ep)
338 if (np->e_entries == ep) {
339 np->e_entries = ep->e_sibling;
341 for (np = np->e_entries; np != NULL; np = np->e_sibling) {
342 if (np->e_sibling == ep) {
343 np->e_sibling = ep->e_sibling;
348 badentry(ep, "cannot find entry in parent list");
353 * Table of unused string entries, sorted by length.
355 * Entries are allocated in STRTBLINCR sized pieces so that names
356 * of similar lengths can use the same entry. The value of STRTBLINCR
357 * is chosen so that every entry has at least enough space to hold
358 * a "struct strtbl" header. Thus every entry can be linked onto an
359 * appropriate free list.
361 * NB. The macro "allocsize" below assumes that "struct strhdr"
362 * has a size that is a power of two.
368 #define STRTBLINCR (sizeof(struct strhdr))
369 #define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1))
371 static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR];
374 * Allocate space for a name. It first looks to see if it already
375 * has an appropriate sized entry, and if not allocates a new one.
387 np = strtblhdr[len / STRTBLINCR].next;
389 strtblhdr[len / STRTBLINCR].next = np->next;
392 cp = malloc((unsigned)allocsize(len));
394 panic("no space for string table\n");
401 * Free space for a name. The resulting entry is linked onto the
402 * appropriate free list.
407 struct strhdr *tp, *np;
409 tp = &strtblhdr[strlen(name) / STRTBLINCR];
410 np = (struct strhdr *)name;
416 * Useful quantities placed at the end of a dumped symbol table.
418 struct symtableheader {
421 int32_t entrytblsize;
429 * dump a snapshot of the symbol table
432 dumpsymtable(char *filename, long checkpt)
434 struct entry *ep, *tep;
436 struct entry temp, *tentry;
437 long mynum = 1, stroff = 0;
439 struct symtableheader hdr;
441 vprintf(stdout, "Check pointing the restore\n");
444 if ((fd = fopen(filename, "w")) == NULL) {
445 fprintf(stderr, "fopen: %s\n", strerror(errno));
446 panic("cannot create save file %s for symbol table\n",
452 * Assign indices to each entry
453 * Write out the string entries
455 for (i = WINO; i <= maxino; i++) {
456 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
457 ep->e_index = mynum++;
458 fwrite(ep->e_name, sizeof(char),
459 (int)allocsize(ep->e_namlen), fd);
463 * Convert pointers to indexes, and output
467 for (i = WINO; i <= maxino; i++) {
468 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
469 memmove(tep, ep, (long)sizeof(struct entry));
470 tep->e_name = (char *)stroff;
471 stroff += allocsize(ep->e_namlen);
472 tep->e_parent = (struct entry *)ep->e_parent->e_index;
473 if (ep->e_links != NULL)
475 (struct entry *)ep->e_links->e_index;
476 if (ep->e_sibling != NULL)
478 (struct entry *)ep->e_sibling->e_index;
479 if (ep->e_entries != NULL)
481 (struct entry *)ep->e_entries->e_index;
482 if (ep->e_next != NULL)
484 (struct entry *)ep->e_next->e_index;
485 fwrite((char *)tep, sizeof(struct entry), 1, fd);
489 * Convert entry pointers to indexes, and output
491 for (i = 0; i < entrytblsize; i++) {
492 if (entry[i] == NULL)
495 tentry = (struct entry *)entry[i]->e_index;
496 fwrite((char *)&tentry, sizeof(struct entry *), 1, fd);
500 hdr.entrytblsize = entrytblsize;
501 hdr.stringsize = stroff;
502 hdr.dumptime = dumptime;
503 hdr.dumpdate = dumpdate;
505 fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd);
507 fprintf(stderr, "fwrite: %s\n", strerror(errno));
508 panic("output error to file %s writing symbol table\n",
515 * Initialize a symbol table from a file
518 initsymtable(char *filename)
523 struct entry *baseep, *lep;
524 struct symtableheader hdr;
529 vprintf(stdout, "Initialize symbol table.\n");
530 if (filename == NULL) {
531 entrytblsize = maxino / HASHFACTOR;
532 entry = (struct entry **)
533 calloc((unsigned)entrytblsize, sizeof(struct entry *));
535 panic("no memory for entry table\n");
536 ep = addentry(".", ROOTINO, NODE);
540 if ((fd = open(filename, O_RDONLY, 0)) < 0) {
541 fprintf(stderr, "open: %s\n", strerror(errno));
542 panic("cannot open symbol table file %s\n", filename);
544 if (fstat(fd, &stbuf) < 0) {
545 fprintf(stderr, "stat: %s\n", strerror(errno));
546 panic("cannot stat symbol table file %s\n", filename);
548 tblsize = stbuf.st_size - sizeof(struct symtableheader);
549 base = calloc(sizeof(char), (unsigned)tblsize);
551 panic("cannot allocate space for symbol table\n");
552 if (read(fd, base, (int)tblsize) < 0 ||
553 read(fd, (char *)&hdr, sizeof(struct symtableheader)) < 0) {
554 fprintf(stderr, "read: %s\n", strerror(errno));
555 panic("cannot read symbol table file %s\n", filename);
560 * For normal continuation, insure that we are using
561 * the next incremental tape
563 if (hdr.dumpdate != dumptime) {
564 if (hdr.dumpdate < dumptime)
565 fprintf(stderr, "Incremental tape too low\n");
567 fprintf(stderr, "Incremental tape too high\n");
573 * For restart, insure that we are using the same tape
575 curfile.action = SKIP;
576 dumptime = hdr.dumptime;
577 dumpdate = hdr.dumpdate;
579 newtapebuf(hdr.ntrec);
583 panic("initsymtable called from command %c\n", command);
587 entrytblsize = hdr.entrytblsize;
588 entry = (struct entry **)
589 (base + tblsize - (entrytblsize * sizeof(struct entry *)));
590 baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry));
591 lep = (struct entry *)entry;
592 for (i = 0; i < entrytblsize; i++) {
593 if (entry[i] == NULL)
595 entry[i] = &baseep[(long)entry[i]];
597 for (ep = &baseep[1]; ep < lep; ep++) {
598 ep->e_name = base + (long)ep->e_name;
599 ep->e_parent = &baseep[(long)ep->e_parent];
600 if (ep->e_sibling != NULL)
601 ep->e_sibling = &baseep[(long)ep->e_sibling];
602 if (ep->e_links != NULL)
603 ep->e_links = &baseep[(long)ep->e_links];
604 if (ep->e_entries != NULL)
605 ep->e_entries = &baseep[(long)ep->e_entries];
606 if (ep->e_next != NULL)
607 ep->e_next = &baseep[(long)ep->e_next];