2 * Copyright (c) 1983, 1993
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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 1.5 2003/11/01 17:16:01 drhodus Exp $
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".
47 #include <sys/param.h>
50 #include <vfs/ufs/dinode.h>
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).
70 static struct entry **entry;
71 static long entrytblsize;
73 static void addino(ino_t, struct entry *);
74 static struct entry *lookupparent(char *);
75 static void removeentry(struct entry *);
78 * Look up an entry by inode number
83 register struct entry *ep;
85 if (inum < WINO || inum >= maxino)
87 for (ep = entry[inum % entrytblsize]; ep != NULL; ep = ep->e_next)
88 if (ep->e_ino == inum)
94 * Add an entry into the entry table
97 addino(ino_t inum, struct entry *np)
101 if (inum < WINO || inum >= maxino)
102 panic("addino: out of range %d\n", inum);
103 epp = &entry[inum % entrytblsize];
108 for (np = np->e_next; np != NULL; np = np->e_next)
109 if (np->e_ino == inum)
110 badentry(np, "duplicate inum");
114 * Delete an entry from the entry table
117 deleteino(ino_t inum)
119 register struct entry *next;
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) {
128 *prev = next->e_next;
131 prev = &next->e_next;
133 panic("deleteino: %d not found\n", inum);
137 * Look up an entry by name
140 lookupname(char *name)
142 register struct entry *ep;
143 register char *np, *cp;
144 char buf[MAXPATHLEN];
147 for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) {
148 for (np = buf; *cp != '/' && *cp != '\0' &&
149 np < &buf[sizeof(buf)]; )
151 if (np == &buf[sizeof(buf)])
154 for ( ; ep != NULL; ep = ep->e_sibling)
155 if (strcmp(ep->e_name, buf) == 0)
166 * Look up the parent of a pathname
168 static struct entry *
169 lookupparent(char *name)
174 tailindex = strrchr(name, '/');
175 if (tailindex == NULL)
178 ep = lookupname(name);
182 if (ep->e_type != NODE)
183 panic("%s is not a directory\n", name);
188 * Determine the current pathname of a node or leaf
191 myname(register struct entry *ep)
194 static char namebuf[MAXPATHLEN];
196 for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) {
198 memmove(cp, ep->e_name, (long)ep->e_namlen);
199 if (ep == lookupino(ROOTINO))
204 panic("%s: pathname too long\n", cp);
209 * Unused symbol table entries are linked together on a free list
210 * headed by the following pointer.
212 static struct entry *freelist = NULL;
215 * add an entry to the symbol table
218 addentry(char *name, ino_t inum, int type)
220 register struct entry *np, *ep;
222 if (freelist != NULL) {
224 freelist = np->e_next;
225 memset(np, 0, (long)sizeof(struct entry));
227 np = (struct entry *)calloc(1, sizeof(struct entry));
229 panic("no memory to extend symbol table\n");
231 np->e_type = type & ~LINK;
232 ep = lookupparent(name);
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);
242 np->e_name = savename(strrchr(name, '/') + 1);
243 np->e_namlen = strlen(np->e_name);
245 np->e_sibling = ep->e_entries;
248 ep = lookupino(inum);
250 panic("link to non-existent name\n");
252 np->e_links = ep->e_links;
254 } else if (inum != 0) {
255 if (lookupino(inum) != NULL)
256 panic("duplicate entry\n");
263 * delete an entry from the symbol table
266 freeentry(register struct entry *ep)
268 register struct entry *np;
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");
279 if (ep->e_ino != 0) {
280 np = lookupino(ep->e_ino);
282 badentry(ep, "lookupino failed");
286 if (ep->e_links != NULL)
287 addino(inum, ep->e_links);
289 for (; np != NULL; np = np->e_links) {
290 if (np->e_links == ep) {
291 np->e_links = ep->e_links;
296 badentry(ep, "link not found");
300 freename(ep->e_name);
301 ep->e_next = freelist;
306 * Relocate an entry in the tree structure
309 moveentry(register struct entry *ep, char *newname)
314 np = lookupparent(newname);
316 badentry(ep, "cannot move ROOT");
317 if (np != ep->e_parent) {
320 ep->e_sibling = np->e_entries;
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;
330 ep->e_flags &= ~TMPNAME;
334 * Remove an entry in the tree structure
337 removeentry(register struct entry *ep)
339 register struct entry *np;
342 if (np->e_entries == ep) {
343 np->e_entries = ep->e_sibling;
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;
352 badentry(ep, "cannot find entry in parent list");
357 * Table of unused string entries, sorted by length.
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.
365 * NB. The macro "allocsize" below assumes that "struct strhdr"
366 * has a size that is a power of two.
372 #define STRTBLINCR (sizeof(struct strhdr))
373 #define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1))
375 static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR];
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.
391 np = strtblhdr[len / STRTBLINCR].next;
393 strtblhdr[len / STRTBLINCR].next = np->next;
396 cp = malloc((unsigned)allocsize(len));
398 panic("no space for string table\n");
400 (void) strcpy(cp, name);
405 * Free space for a name. The resulting entry is linked onto the
406 * appropriate free list.
411 struct strhdr *tp, *np;
413 tp = &strtblhdr[strlen(name) / STRTBLINCR];
414 np = (struct strhdr *)name;
420 * Useful quantities placed at the end of a dumped symbol table.
422 struct symtableheader {
425 int32_t entrytblsize;
433 * dump a snapshot of the symbol table
436 dumpsymtable(char *filename, long checkpt)
438 register struct entry *ep, *tep;
440 struct entry temp, *tentry;
441 long mynum = 1, stroff = 0;
443 struct symtableheader hdr;
445 vprintf(stdout, "Check pointing the restore\n");
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",
456 * Assign indices to each entry
457 * Write out the string entries
459 for (i = WINO; i <= maxino; i++) {
460 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
461 ep->e_index = mynum++;
462 (void) fwrite(ep->e_name, sizeof(char),
463 (int)allocsize(ep->e_namlen), fd);
467 * Convert pointers to indexes, and output
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)
479 (struct entry *)ep->e_links->e_index;
480 if (ep->e_sibling != NULL)
482 (struct entry *)ep->e_sibling->e_index;
483 if (ep->e_entries != NULL)
485 (struct entry *)ep->e_entries->e_index;
486 if (ep->e_next != NULL)
488 (struct entry *)ep->e_next->e_index;
489 (void) fwrite((char *)tep, sizeof(struct entry), 1, fd);
493 * Convert entry pointers to indexes, and output
495 for (i = 0; i < entrytblsize; i++) {
496 if (entry[i] == NULL)
499 tentry = (struct entry *)entry[i]->e_index;
500 (void) fwrite((char *)&tentry, sizeof(struct entry *), 1, fd);
504 hdr.entrytblsize = entrytblsize;
505 hdr.stringsize = stroff;
506 hdr.dumptime = dumptime;
507 hdr.dumpdate = dumpdate;
509 (void) fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd);
511 fprintf(stderr, "fwrite: %s\n", strerror(errno));
512 panic("output error to file %s writing symbol table\n",
519 * Initialize a symbol table from a file
522 initsymtable(char *filename)
526 register struct entry *ep;
527 struct entry *baseep, *lep;
528 struct symtableheader hdr;
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);
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);
548 if (fstat(fd, &stbuf) < 0) {
549 fprintf(stderr, "stat: %s\n", strerror(errno));
550 panic("cannot stat symbol table file %s\n", filename);
552 tblsize = stbuf.st_size - sizeof(struct symtableheader);
553 base = calloc(sizeof(char), (unsigned)tblsize);
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);
564 * For normal continuation, insure that we are using
565 * the next incremental tape
567 if (hdr.dumpdate != dumptime) {
568 if (hdr.dumpdate < dumptime)
569 fprintf(stderr, "Incremental tape too low\n");
571 fprintf(stderr, "Incremental tape too high\n");
577 * For restart, insure that we are using the same tape
579 curfile.action = SKIP;
580 dumptime = hdr.dumptime;
581 dumpdate = hdr.dumpdate;
583 newtapebuf(hdr.ntrec);
587 panic("initsymtable called from command %c\n", command);
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)
599 entry[i] = &baseep[(long)entry[i]];
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];