2 * Ported to Linux's Second Extended File System as part of the
3 * dump and restore backup suit
4 * Remy Card <card@Linux.EU.Org>, 1994-1997
5 * Stelian Pop <stelian@popies.net>, 1999-2000
6 * Stelian Pop <stelian@popies.net> - AlcĂ´ve <www.alcove.com>, 2000-2002
10 * Copyright (c) 1983, 1993
11 * The Regents of the University of California. All rights reserved.
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 static const char rcsid[] =
40 "$Id: symtab.c,v 1.28 2010/06/11 11:19:17 stelian Exp $";
44 * These routines maintain the symbol table which tracks the state
45 * of the file system being restored. They provide lookup by either
46 * name or inode number. They also provide for creation, deletion,
47 * and renaming of entries. Because of the dynamic nature of pathnames,
48 * names should not be saved, but always constructed just before they
49 * are needed, by calling "myname".
53 #include <compatlfs.h>
54 #include <sys/param.h>
60 #ifdef HAVE_EXT2FS_EXT2_FS_H
61 #include <ext2fs/ext2_fs.h>
63 #include <linux/ext2_fs.h>
65 #include <bsdcompat.h>
68 #include <sys/fcntl.h>
69 #include <bsdcompat.h>
71 #include <ufs/ufs/dinode.h>
73 #endif /* __linux__ */
76 #include <compaterr.h>
84 #include <ext2fs/ext2fs.h>
91 * The following variables define the inode symbol table.
92 * The primary hash table is dynamically allocated based on
93 * the number of inodes in the file system (maxino), scaled by
94 * HASHFACTOR. The variable "entry" points to the hash table;
95 * the variable "entrytblsize" indicates its size (in entries).
98 static struct entry **entry;
99 static long entrytblsize;
101 static void addino __P((dump_ino_t, struct entry *));
102 static struct entry *lookupparent __P((char *));
103 static void removeentry __P((struct entry *));
104 static int dir_hash __P((char *));
107 * Returns a hash given a file name
112 unsigned long hash0 = 0x12a3fe2d, hash1 = 0x37abe8f9;
113 int len = strlen(name);
116 unsigned long hash = hash1 + (hash0 ^ (*name++ * 7152373));
117 if (hash & 0x80000000) hash -= 0x7fffffff;
121 return hash0 % dirhash_size;
125 * Look up an entry by inode number
128 lookupino(dump_ino_t inum)
132 if (inum < WINO || inum >= maxino)
134 for (ep = entry[inum % entrytblsize]; ep != NULL; ep = ep->e_next)
135 if (ep->e_ino == inum)
141 * Add an entry into the entry table
144 addino(dump_ino_t inum, struct entry *np)
148 if (inum < WINO || inum >= maxino)
149 panic("addino: out of range %d\n", inum);
150 epp = &entry[inum % entrytblsize];
155 for (np = np->e_next; np != NULL; np = np->e_next)
156 if (np->e_ino == inum)
157 badentry(np, "duplicate inum");
161 * Delete an entry from the entry table
164 deleteino(dump_ino_t inum)
169 if (inum < WINO || inum >= maxino)
170 panic("deleteino: out of range %d\n", inum);
171 prev = &entry[inum % entrytblsize];
172 for (next = *prev; next != NULL; next = next->e_next) {
173 if (next->e_ino == inum) {
175 *prev = next->e_next;
178 prev = &next->e_next;
180 panic("deleteino: %d not found\n", inum);
184 * Look up an entry by name
187 lookupname(char *name)
189 struct entry *ep, *oldep;
191 char buf[MAXPATHLEN];
193 ep = lookupino(ROOTINO);
204 for (np = buf; *cp != '/' && *cp != '\0' &&
205 np < &buf[sizeof(buf)]; )
207 if (np == &buf[sizeof(buf)])
213 if (ep->e_entries != NULL) {
215 ep = ep->e_entries[dir_hash(buf)];
216 for ( ; ep != NULL; ep = ep->e_sibling)
217 if (strcmp(ep->e_name, buf) == 0)
220 /* search all hash lists for renamed inodes */
223 for (j = 0; j < dirhash_size; j++) {
224 ep = oldep->e_entries[j];
225 for ( ; ep != NULL; ep = ep->e_sibling)
226 if (strcmp(ep->e_name, buf) == 0)
243 * Look up the parent of a pathname
245 static struct entry *
246 lookupparent(char *name)
251 tailindex = strrchr(name, '/');
252 if (tailindex == NULL)
255 ep = lookupname(name);
259 if (ep->e_type != NODE)
260 panic("%s is not a directory\n", name);
265 * Determine the current pathname of a node or leaf
268 myname(struct entry *ep)
271 static char namebuf[MAXPATHLEN];
273 for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) {
275 memmove(cp, ep->e_name, (size_t)ep->e_namlen);
276 if (ep == lookupino(ROOTINO))
281 panic("%s: pathname too long\n", cp);
286 * Unused symbol table entries are linked together on a free list
287 * headed by the following pointer.
289 static struct entry *freelist = NULL;
292 * add an entry to the symbol table
295 addentry(char *name, dump_ino_t inum, int type)
297 struct entry *np, *ep;
299 if (freelist != NULL) {
301 freelist = np->e_next;
302 memset(np, 0, sizeof(struct entry));
304 np = (struct entry *)calloc(1, sizeof(struct entry));
306 errx(1, "no memory to extend symbol table");
308 np->e_type = type & ~LINK;
310 np->e_entries = calloc(1, dirhash_size * sizeof(struct entry *));
311 if (np->e_entries == NULL)
312 panic("unable to allocate directory entries\n");
314 ep = lookupparent(name);
316 if (inum != ROOTINO || lookupino(ROOTINO) != NULL)
317 panic("bad name to addentry %s\n", name);
318 np->e_name = savename(name);
319 np->e_namlen = strlen(name);
324 np->e_name = savename(strrchr(name, '/') + 1);
325 np->e_namlen = strlen(np->e_name);
327 np->e_sibling = ep->e_entries[dir_hash(np->e_name)];
328 ep->e_entries[dir_hash(np->e_name)] = np;
330 ep = lookupino(inum);
332 panic("link to non-existent name\n");
334 np->e_links = ep->e_links;
336 } else if (inum != 0) {
337 if (lookupino(inum) != NULL)
338 panic("duplicate entry\n");
345 * delete an entry from the symbol table
348 freeentry(struct entry *ep)
353 if (ep->e_flags != REMOVED)
354 badentry(ep, "not marked REMOVED");
355 if (ep->e_type == NODE) {
356 if (ep->e_links != NULL)
357 badentry(ep, "freeing referenced directory");
358 if (ep->e_entries != NULL) {
360 for (i = 0; i < dirhash_size; i++) {
361 if (ep->e_entries[i] != NULL)
362 badentry(ep, "freeing non-empty directory");
366 if (ep->e_ino != 0) {
367 np = lookupino(ep->e_ino);
369 badentry(ep, "lookupino failed");
373 if (ep->e_links != NULL)
374 addino(inum, ep->e_links);
376 for (; np != NULL; np = np->e_links) {
377 if (np->e_links == ep) {
378 np->e_links = ep->e_links;
383 badentry(ep, "link not found");
387 freename(ep->e_name);
388 ep->e_next = freelist;
393 * Relocate an entry in the tree structure
396 moveentry(struct entry *ep, char *newname)
401 np = lookupparent(newname);
403 badentry(ep, "cannot move ROOT");
404 if (np != ep->e_parent) {
407 ep->e_sibling = np->e_entries[dir_hash(ep->e_name)];
408 np->e_entries[dir_hash(ep->e_name)] = ep;
410 cp = strrchr(newname, '/') + 1;
411 freename(ep->e_name);
412 ep->e_name = savename(cp);
413 ep->e_namlen = strlen(cp);
414 if (strcmp(gentempname(ep), ep->e_name) == 0)
415 ep->e_flags |= TMPNAME;
417 ep->e_flags &= ~TMPNAME;
421 * Remove an entry in the tree structure
424 removeentry(struct entry *ep)
426 struct entry *np = ep->e_parent;
427 struct entry *entry = np->e_entries[dir_hash(ep->e_name)];
430 np->e_entries[dir_hash(ep->e_name)] = ep->e_sibling;
432 for (np = entry; np != NULL; np = np->e_sibling) {
433 if (np->e_sibling == ep) {
434 np->e_sibling = ep->e_sibling;
440 /* search all hash lists for renamed inodes */
442 for (j = 0; j < dirhash_size; j++) {
444 entry = np->e_entries[j];
446 np->e_entries[j] = ep->e_sibling;
450 for (np = entry; np != NULL; np = np->e_sibling) {
451 if (np->e_sibling == ep) {
452 np->e_sibling = ep->e_sibling;
458 badentry(ep, "cannot find entry in parent list");
464 * Table of unused string entries, sorted by length.
466 * Entries are allocated in STRTBLINCR sized pieces so that names
467 * of similar lengths can use the same entry. The value of STRTBLINCR
468 * is chosen so that every entry has at least enough space to hold
469 * a "struct strtbl" header. Thus every entry can be linked onto an
470 * appropriate free list.
472 * NB. The macro "allocsize" below assumes that "struct strhdr"
473 * has a size that is a power of two.
479 #define STRTBLINCR (sizeof(struct strhdr))
480 #define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1))
482 static struct strhdr strtblhdr[allocsize(MAXNAMLEN) / STRTBLINCR];
485 * Allocate space for a name. It first looks to see if it already
486 * has an appropriate sized entry, and if not allocates a new one.
498 np = strtblhdr[len / STRTBLINCR].next;
500 strtblhdr[len / STRTBLINCR].next = np->next;
503 cp = malloc((unsigned)allocsize(len));
505 errx(1, "no space for string table");
507 (void) strcpy(cp, name);
512 * Free space for a name. The resulting entry is linked onto the
513 * appropriate free list.
518 struct strhdr *tp, *np;
520 tp = &strtblhdr[strlen(name) / STRTBLINCR];
521 np = (struct strhdr *)name;
527 * Useful quantities placed at the end of a dumped symbol table.
529 struct symtableheader {
533 int32_t entrytblsize;
542 * dump a snapshot of the symbol table
545 dumpsymtable(char *filename, long checkpt)
547 struct entry *ep, *tep;
549 struct entry temp, *tentry;
550 long mynum = 1, stroff = 0, hashoff = 0;
552 struct symtableheader hdr;
553 struct entry **temphash;
555 Vprintf(stdout, "Check pointing the restore\n");
558 if ((fd = FOPEN(filename, "w")) == NULL) {
560 panic("cannot create save file %s for symbol table\n",
565 * Assign indices to each entry
566 * Write out the string entries
568 for (i = WINO; i <= maxino; i++) {
569 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
570 ep->e_index = mynum++;
571 (void) fwrite(ep->e_name, (int)allocsize(ep->e_namlen),
576 * Write out e_entries tables
578 temphash = calloc(1, dirhash_size * sizeof(struct entry *));
579 if (temphash == NULL)
580 errx(1, "no memory for saving hashtable");
581 for (i = WINO; i <= maxino; i++) {
582 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
583 if (ep->e_entries != NULL) {
585 memcpy(temphash, ep->e_entries, dirhash_size * sizeof(struct entry *));
586 for (j = 0; j < dirhash_size; j++) {
588 temphash[j] = (struct entry *)ep->e_entries[j]->e_index;
590 fwrite(temphash, sizeof(struct entry *), dirhash_size, fd);
597 * Convert pointers to indexes, and output
602 for (i = WINO; i <= maxino; i++) {
603 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
604 memmove(tep, ep, sizeof(struct entry));
605 tep->e_name = (char *)stroff;
606 stroff += allocsize(ep->e_namlen);
607 tep->e_parent = (struct entry *)ep->e_parent->e_index;
608 if (ep->e_links != NULL)
610 (struct entry *)ep->e_links->e_index;
611 if (ep->e_sibling != NULL)
613 (struct entry *)ep->e_sibling->e_index;
614 if (ep->e_entries != NULL) {
615 tep->e_entries = (struct entry **)hashoff;
616 hashoff += dirhash_size * sizeof(struct entry *);
618 if (ep->e_next != NULL)
620 (struct entry *)ep->e_next->e_index;
621 (void) fwrite((char *)tep, sizeof(struct entry), 1, fd);
625 * Convert entry pointers to indexes, and output
627 for (i = 0; (long)i < entrytblsize; i++) {
628 if (entry[i] == NULL)
631 tentry = (struct entry *)entry[i]->e_index;
632 (void) fwrite((char *)&tentry, sizeof(struct entry *), 1, fd);
636 hdr.entrytblsize = entrytblsize;
637 hdr.stringsize = stroff;
638 hdr.hashsize = hashoff;
639 hdr.dumptime = dumptime;
640 hdr.dumpdate = dumpdate;
643 (void) fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd);
646 panic("output error to file %s writing symbol table\n",
653 * Initialize a symbol table from a file
656 initsymtable(char *filename)
661 struct entry *baseep, *lep;
662 struct symtableheader hdr;
667 Vprintf(stdout, "Initialize symbol table.\n");
668 if (filename == NULL) {
669 entrytblsize = maxino / HASHFACTOR;
670 entry = (struct entry **)
671 calloc((unsigned)entrytblsize, sizeof(struct entry *));
672 if (entry == (struct entry **)NULL)
673 errx(1, "no memory for entry table");
674 ep = addentry(".", ROOTINO, NODE);
678 if ((fd = OPEN(filename, O_RDONLY, 0)) < 0) {
680 errx(1, "cannot open symbol table file %s", filename);
682 if (FSTAT(fd, &stbuf) < 0) {
684 errx(1, "cannot stat symbol table file %s", filename);
686 tblsize = stbuf.st_size - sizeof(struct symtableheader);
687 base = calloc(sizeof(char), (unsigned)tblsize);
689 errx(1, "cannot allocate space for symbol table");
690 if (read(fd, base, (int)tblsize) < 0 ||
691 read(fd, (char *)&hdr, sizeof(struct symtableheader)) < 0) {
693 errx(1, "cannot read symbol table file %s", filename);
698 * For normal continuation, insure that we are using
699 * the next incremental tape
701 if (hdr.dumpdate != dumptime)
702 errx(1, "Incremental tape too %s",
703 (hdr.dumpdate < dumptime) ? "low" : "high");
707 * For restart, insure that we are using the same tape
709 curfile.action = SKIP;
710 dumptime = hdr.dumptime;
711 dumpdate = hdr.dumpdate;
714 newtapebuf(hdr.ntrec);
718 panic("initsymtable called from command %c\n", command);
721 if (hdr.maxino > maxino) {
722 resizemaps(maxino, hdr.maxino);
725 entrytblsize = hdr.entrytblsize;
726 entry = (struct entry **)
727 (base + tblsize - (entrytblsize * sizeof(struct entry *)));
728 baseep = (struct entry *)(base + hdr.stringsize + hdr.hashsize - sizeof(struct entry));
729 lep = (struct entry *)entry;
730 for (i = 0; i < entrytblsize; i++) {
731 if (entry[i] == NULL)
733 entry[i] = &baseep[(long)entry[i]];
735 for (ep = &baseep[1]; ep < lep; ep++) {
736 ep->e_name = base + (long)ep->e_name;
737 ep->e_parent = &baseep[(long)ep->e_parent];
738 if (ep->e_sibling != NULL)
739 ep->e_sibling = &baseep[(long)ep->e_sibling];
740 if (ep->e_links != NULL)
741 ep->e_links = &baseep[(long)ep->e_links];
742 if (ep->e_type == NODE) {
744 ep->e_entries = (struct entry **)(base + hdr.stringsize + (long)ep->e_entries);
745 for (i = 0; i < dirhash_size; i++) {
746 if (ep->e_entries[i])
747 ep->e_entries[i] = &baseep[(long)ep->e_entries[i]];
751 ep->e_entries = NULL;
752 if (ep->e_next != NULL)
753 ep->e_next = &baseep[(long)ep->e_next];