2 * Copyright (c) 1983, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
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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.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 static char sccsid[] = "@(#)symtab.c 8.3 (Berkeley) 4/28/95";
38 static const char rcsid[] =
43 * These routines maintain the symbol table which tracks the state
44 * of the file system being restored. They provide lookup by either
45 * name or inode number. They also provide for creation, deletion,
46 * and renaming of entries. Because of the dynamic nature of pathnames,
47 * names should not be saved, but always constructed just before they
48 * are needed, by calling "myname".
51 #include <sys/param.h>
54 #include <ufs/ufs/dinode.h>
68 * The following variables define the inode symbol table.
69 * The primary hash table is dynamically allocated based on
70 * the number of inodes in the file system (maxino), scaled by
71 * HASHFACTOR. The variable "entry" points to the hash table;
72 * the variable "entrytblsize" indicates its size (in entries).
75 static struct entry **entry;
76 static long entrytblsize;
78 static void addino(ino_t, struct entry *);
79 static struct entry *lookupparent(char *);
80 static void removeentry(struct entry *);
83 * Look up an entry by inode number
90 if (inum < WINO || inum >= maxino)
92 for (ep = entry[inum % entrytblsize]; ep != NULL; ep = ep->e_next)
93 if (ep->e_ino == inum)
99 * Add an entry into the entry table
102 addino(ino_t inum, struct entry *np)
106 if (inum < WINO || inum >= maxino)
107 panic("addino: out of range %d\n", inum);
108 epp = &entry[inum % entrytblsize];
113 for (np = np->e_next; np != NULL; np = np->e_next)
114 if (np->e_ino == inum)
115 badentry(np, "duplicate inum");
119 * Delete an entry from the entry table
122 deleteino(ino_t inum)
127 if (inum < WINO || inum >= maxino)
128 panic("deleteino: out of range %d\n", inum);
129 prev = &entry[inum % entrytblsize];
130 for (next = *prev; next != NULL; next = next->e_next) {
131 if (next->e_ino == inum) {
133 *prev = next->e_next;
136 prev = &next->e_next;
138 panic("deleteino: %d not found\n", inum);
142 * Look up an entry by name
145 lookupname(char *name)
149 char buf[MAXPATHLEN];
152 for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) {
153 for (np = buf; *cp != '/' && *cp != '\0' &&
154 np < &buf[sizeof(buf)]; )
156 if (np == &buf[sizeof(buf)])
159 for ( ; ep != NULL; ep = ep->e_sibling)
160 if (strcmp(ep->e_name, buf) == 0)
171 * Look up the parent of a pathname
173 static struct entry *
174 lookupparent(char *name)
179 tailindex = strrchr(name, '/');
180 if (tailindex == NULL)
183 ep = lookupname(name);
187 if (ep->e_type != NODE)
188 panic("%s is not a directory\n", name);
193 * Determine the current pathname of a node or leaf
196 myname(struct entry *ep)
199 static char namebuf[MAXPATHLEN];
201 for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) {
203 memmove(cp, ep->e_name, (long)ep->e_namlen);
204 if (ep == lookupino(ROOTINO))
209 panic("%s: pathname too long\n", cp);
214 * Unused symbol table entries are linked together on a free list
215 * headed by the following pointer.
217 static struct entry *freelist = NULL;
220 * add an entry to the symbol table
223 addentry(char *name, ino_t inum, int type)
225 struct entry *np, *ep;
227 if (freelist != NULL) {
229 freelist = np->e_next;
230 memset(np, 0, (long)sizeof(struct entry));
232 np = (struct entry *)calloc(1, sizeof(struct entry));
234 panic("no memory to extend symbol table\n");
236 np->e_type = type & ~LINK;
237 ep = lookupparent(name);
239 if (inum != ROOTINO || lookupino(ROOTINO) != NULL)
240 panic("bad name to addentry %s\n", name);
241 np->e_name = savename(name);
242 np->e_namlen = strlen(name);
247 np->e_name = savename(strrchr(name, '/') + 1);
248 np->e_namlen = strlen(np->e_name);
250 np->e_sibling = ep->e_entries;
253 ep = lookupino(inum);
255 panic("link to non-existent name\n");
257 np->e_links = ep->e_links;
259 } else if (inum != 0) {
260 if (lookupino(inum) != NULL)
261 panic("duplicate entry\n");
268 * delete an entry from the symbol table
271 freeentry(struct entry *ep)
276 if (ep->e_flags != REMOVED)
277 badentry(ep, "not marked REMOVED");
278 if (ep->e_type == NODE) {
279 if (ep->e_links != NULL)
280 badentry(ep, "freeing referenced directory");
281 if (ep->e_entries != NULL)
282 badentry(ep, "freeing non-empty directory");
284 if (ep->e_ino != 0) {
285 np = lookupino(ep->e_ino);
287 badentry(ep, "lookupino failed");
291 if (ep->e_links != NULL)
292 addino(inum, ep->e_links);
294 for (; np != NULL; np = np->e_links) {
295 if (np->e_links == ep) {
296 np->e_links = ep->e_links;
301 badentry(ep, "link not found");
305 freename(ep->e_name);
306 ep->e_next = freelist;
311 * Relocate an entry in the tree structure
314 moveentry(struct entry *ep, char *newname)
319 np = lookupparent(newname);
321 badentry(ep, "cannot move ROOT");
322 if (np != ep->e_parent) {
325 ep->e_sibling = np->e_entries;
328 cp = strrchr(newname, '/') + 1;
329 freename(ep->e_name);
330 ep->e_name = savename(cp);
331 ep->e_namlen = strlen(cp);
332 if (strcmp(gentempname(ep), ep->e_name) == 0)
333 ep->e_flags |= TMPNAME;
335 ep->e_flags &= ~TMPNAME;
339 * Remove an entry in the tree structure
342 removeentry(struct entry *ep)
347 if (np->e_entries == ep) {
348 np->e_entries = ep->e_sibling;
350 for (np = np->e_entries; np != NULL; np = np->e_sibling) {
351 if (np->e_sibling == ep) {
352 np->e_sibling = ep->e_sibling;
357 badentry(ep, "cannot find entry in parent list");
362 * Table of unused string entries, sorted by length.
364 * Entries are allocated in STRTBLINCR sized pieces so that names
365 * of similar lengths can use the same entry. The value of STRTBLINCR
366 * is chosen so that every entry has at least enough space to hold
367 * a "struct strtbl" header. Thus every entry can be linked onto an
368 * appropriate free list.
370 * NB. The macro "allocsize" below assumes that "struct strhdr"
371 * has a size that is a power of two.
377 #define STRTBLINCR (sizeof(struct strhdr))
378 #define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1))
380 static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR];
383 * Allocate space for a name. It first looks to see if it already
384 * has an appropriate sized entry, and if not allocates a new one.
396 np = strtblhdr[len / STRTBLINCR].next;
398 strtblhdr[len / STRTBLINCR].next = np->next;
401 cp = malloc((unsigned)allocsize(len));
403 panic("no space for string table\n");
405 (void) strcpy(cp, name);
410 * Free space for a name. The resulting entry is linked onto the
411 * appropriate free list.
416 struct strhdr *tp, *np;
418 tp = &strtblhdr[strlen(name) / STRTBLINCR];
419 np = (struct strhdr *)name;
425 * Useful quantities placed at the end of a dumped symbol table.
427 struct symtableheader {
430 int32_t entrytblsize;
438 * dump a snapshot of the symbol table
441 dumpsymtable(char *filename, long checkpt)
443 struct entry *ep, *tep;
445 struct entry temp, *tentry;
446 long mynum = 1, stroff = 0;
448 struct symtableheader hdr;
450 vprintf(stdout, "Check pointing the restore\n");
453 if ((fd = fopen(filename, "w")) == NULL) {
454 fprintf(stderr, "fopen: %s\n", strerror(errno));
455 panic("cannot create save file %s for symbol table\n",
461 * Assign indices to each entry
462 * Write out the string entries
464 for (i = WINO; i <= maxino; i++) {
465 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
466 ep->e_index = mynum++;
467 (void) fwrite(ep->e_name, sizeof(char),
468 (int)allocsize(ep->e_namlen), fd);
472 * Convert pointers to indexes, and output
476 for (i = WINO; i <= maxino; i++) {
477 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
478 memmove(tep, ep, (long)sizeof(struct entry));
479 tep->e_name = (char *)stroff;
480 stroff += allocsize(ep->e_namlen);
481 tep->e_parent = (struct entry *)ep->e_parent->e_index;
482 if (ep->e_links != NULL)
484 (struct entry *)ep->e_links->e_index;
485 if (ep->e_sibling != NULL)
487 (struct entry *)ep->e_sibling->e_index;
488 if (ep->e_entries != NULL)
490 (struct entry *)ep->e_entries->e_index;
491 if (ep->e_next != NULL)
493 (struct entry *)ep->e_next->e_index;
494 (void) fwrite((char *)tep, sizeof(struct entry), 1, fd);
498 * Convert entry pointers to indexes, and output
500 for (i = 0; i < entrytblsize; i++) {
501 if (entry[i] == NULL)
504 tentry = (struct entry *)entry[i]->e_index;
505 (void) fwrite((char *)&tentry, sizeof(struct entry *), 1, fd);
509 hdr.entrytblsize = entrytblsize;
510 hdr.stringsize = stroff;
511 hdr.dumptime = dumptime;
512 hdr.dumpdate = dumpdate;
514 (void) fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd);
516 fprintf(stderr, "fwrite: %s\n", strerror(errno));
517 panic("output error to file %s writing symbol table\n",
524 * Initialize a symbol table from a file
527 initsymtable(char *filename)
532 struct entry *baseep, *lep;
533 struct symtableheader hdr;
538 vprintf(stdout, "Initialize symbol table.\n");
539 if (filename == NULL) {
540 entrytblsize = maxino / HASHFACTOR;
541 entry = (struct entry **)
542 calloc((unsigned)entrytblsize, sizeof(struct entry *));
543 if (entry == (struct entry **)NULL)
544 panic("no memory for entry table\n");
545 ep = addentry(".", ROOTINO, NODE);
549 if ((fd = open(filename, O_RDONLY, 0)) < 0) {
550 fprintf(stderr, "open: %s\n", strerror(errno));
551 panic("cannot open symbol table file %s\n", filename);
553 if (fstat(fd, &stbuf) < 0) {
554 fprintf(stderr, "stat: %s\n", strerror(errno));
555 panic("cannot stat symbol table file %s\n", filename);
557 tblsize = stbuf.st_size - sizeof(struct symtableheader);
558 base = calloc(sizeof(char), (unsigned)tblsize);
560 panic("cannot allocate space for symbol table\n");
561 if (read(fd, base, (int)tblsize) < 0 ||
562 read(fd, (char *)&hdr, sizeof(struct symtableheader)) < 0) {
563 fprintf(stderr, "read: %s\n", strerror(errno));
564 panic("cannot read symbol table file %s\n", filename);
569 * For normal continuation, insure that we are using
570 * the next incremental tape
572 if (hdr.dumpdate != dumptime) {
573 if (hdr.dumpdate < dumptime)
574 fprintf(stderr, "Incremental tape too low\n");
576 fprintf(stderr, "Incremental tape too high\n");
582 * For restart, insure that we are using the same tape
584 curfile.action = SKIP;
585 dumptime = hdr.dumptime;
586 dumpdate = hdr.dumpdate;
588 newtapebuf(hdr.ntrec);
592 panic("initsymtable called from command %c\n", command);
596 entrytblsize = hdr.entrytblsize;
597 entry = (struct entry **)
598 (base + tblsize - (entrytblsize * sizeof(struct entry *)));
599 baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry));
600 lep = (struct entry *)entry;
601 for (i = 0; i < entrytblsize; i++) {
602 if (entry[i] == NULL)
604 entry[i] = &baseep[(long)entry[i]];
606 for (ep = &baseep[1]; ep < lep; ep++) {
607 ep->e_name = base + (long)ep->e_name;
608 ep->e_parent = &baseep[(long)ep->e_parent];
609 if (ep->e_sibling != NULL)
610 ep->e_sibling = &baseep[(long)ep->e_sibling];
611 if (ep->e_links != NULL)
612 ep->e_links = &baseep[(long)ep->e_links];
613 if (ep->e_entries != NULL)
614 ep->e_entries = &baseep[(long)ep->e_entries];
615 if (ep->e_next != NULL)
616 ep->e_next = &baseep[(long)ep->e_next];