2 * Copyright (c) 1983, 1993
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32 static char sccsid[] = "@(#)symtab.c 8.3 (Berkeley) 4/28/95";
34 static const char rcsid[] =
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 <ufs/ufs/dinode.h>
65 * The following variables define the inode symbol table.
66 * The primary hash table is dynamically allocated based on
67 * the number of inodes in the file system (maxino), scaled by
68 * HASHFACTOR. The variable "entry" points to the hash table;
69 * the variable "entrytblsize" indicates its size (in entries).
72 static struct entry **entry;
73 static long entrytblsize;
75 static void addino(ino_t, struct entry *);
76 static struct entry *lookupparent(char *);
77 static void removeentry(struct entry *);
80 * Look up an entry by inode number
87 if (inum < WINO || inum >= maxino)
89 for (ep = entry[inum % entrytblsize]; ep != NULL; ep = ep->e_next)
90 if (ep->e_ino == inum)
96 * Add an entry into the entry table
99 addino(ino_t inum, struct entry *np)
103 if (inum < WINO || inum >= maxino)
104 panic("addino: out of range %ju\n", (uintmax_t)inum);
105 epp = &entry[inum % entrytblsize];
110 for (np = np->e_next; np != NULL; np = np->e_next)
111 if (np->e_ino == inum)
112 badentry(np, "duplicate inum");
116 * Delete an entry from the entry table
119 deleteino(ino_t inum)
124 if (inum < WINO || inum >= maxino)
125 panic("deleteino: out of range %ju\n", (uintmax_t)inum);
126 prev = &entry[inum % entrytblsize];
127 for (next = *prev; next != NULL; next = next->e_next) {
128 if (next->e_ino == inum) {
130 *prev = next->e_next;
133 prev = &next->e_next;
135 panic("deleteino: %ju not found\n", (uintmax_t)inum);
139 * Look up an entry by name
142 lookupname(char *name)
146 char buf[MAXPATHLEN];
149 for (ep = lookupino(ROOTINO); ep != NULL; ep = ep->e_entries) {
150 for (np = buf; *cp != '/' && *cp != '\0' &&
151 np < &buf[sizeof(buf)]; )
153 if (np == &buf[sizeof(buf)])
156 for ( ; ep != NULL; ep = ep->e_sibling)
157 if (strcmp(ep->e_name, buf) == 0)
168 * Look up the parent of a pathname
170 static struct entry *
171 lookupparent(char *name)
176 tailindex = strrchr(name, '/');
177 if (tailindex == NULL)
180 ep = lookupname(name);
184 if (ep->e_type != NODE)
185 panic("%s is not a directory\n", name);
190 * Determine the current pathname of a node or leaf
193 myname(struct entry *ep)
196 static char namebuf[MAXPATHLEN];
198 for (cp = &namebuf[MAXPATHLEN - 2]; cp > &namebuf[ep->e_namlen]; ) {
200 memmove(cp, ep->e_name, (long)ep->e_namlen);
201 if (ep == lookupino(ROOTINO))
206 panic("%s: pathname too long\n", cp);
211 * Unused symbol table entries are linked together on a free list
212 * headed by the following pointer.
214 static struct entry *freelist = NULL;
217 * add an entry to the symbol table
220 addentry(char *name, ino_t inum, int type)
222 struct entry *np, *ep;
224 if (freelist != NULL) {
226 freelist = np->e_next;
227 memset(np, 0, (long)sizeof(struct entry));
229 np = (struct entry *)calloc(1, sizeof(struct entry));
231 panic("no memory to extend symbol table\n");
233 np->e_type = type & ~LINK;
234 ep = lookupparent(name);
236 if (inum != ROOTINO || lookupino(ROOTINO) != NULL)
237 panic("bad name to addentry %s\n", name);
238 np->e_name = savename(name);
239 np->e_namlen = strlen(name);
244 np->e_name = savename(strrchr(name, '/') + 1);
245 np->e_namlen = strlen(np->e_name);
247 np->e_sibling = ep->e_entries;
250 ep = lookupino(inum);
252 panic("link to non-existent name\n");
254 np->e_links = ep->e_links;
256 } else if (inum != 0) {
257 if (lookupino(inum) != NULL)
258 panic("duplicate entry\n");
265 * delete an entry from the symbol table
268 freeentry(struct entry *ep)
273 if (ep->e_flags != REMOVED)
274 badentry(ep, "not marked REMOVED");
275 if (ep->e_type == NODE) {
276 if (ep->e_links != NULL)
277 badentry(ep, "freeing referenced directory");
278 if (ep->e_entries != NULL)
279 badentry(ep, "freeing non-empty directory");
281 if (ep->e_ino != 0) {
282 np = lookupino(ep->e_ino);
284 badentry(ep, "lookupino failed");
288 if (ep->e_links != NULL)
289 addino(inum, ep->e_links);
291 for (; np != NULL; np = np->e_links) {
292 if (np->e_links == ep) {
293 np->e_links = ep->e_links;
298 badentry(ep, "link not found");
302 freename(ep->e_name);
303 ep->e_next = freelist;
308 * Relocate an entry in the tree structure
311 moveentry(struct entry *ep, char *newname)
316 np = lookupparent(newname);
318 badentry(ep, "cannot move ROOT");
319 if (np != ep->e_parent) {
322 ep->e_sibling = np->e_entries;
325 cp = strrchr(newname, '/') + 1;
326 freename(ep->e_name);
327 ep->e_name = savename(cp);
328 ep->e_namlen = strlen(cp);
329 if (strcmp(gentempname(ep), ep->e_name) == 0)
330 ep->e_flags |= TMPNAME;
332 ep->e_flags &= ~TMPNAME;
336 * Remove an entry in the tree structure
339 removeentry(struct entry *ep)
344 if (np->e_entries == ep) {
345 np->e_entries = ep->e_sibling;
347 for (np = np->e_entries; np != NULL; np = np->e_sibling) {
348 if (np->e_sibling == ep) {
349 np->e_sibling = ep->e_sibling;
354 badentry(ep, "cannot find entry in parent list");
359 * Table of unused string entries, sorted by length.
361 * Entries are allocated in STRTBLINCR sized pieces so that names
362 * of similar lengths can use the same entry. The value of STRTBLINCR
363 * is chosen so that every entry has at least enough space to hold
364 * a "struct strtbl" header. Thus every entry can be linked onto an
365 * appropriate free list.
367 * NB. The macro "allocsize" below assumes that "struct strhdr"
368 * has a size that is a power of two.
374 #define STRTBLINCR (sizeof(struct strhdr))
375 #define allocsize(size) (((size) + 1 + STRTBLINCR - 1) & ~(STRTBLINCR - 1))
377 static struct strhdr strtblhdr[allocsize(NAME_MAX) / STRTBLINCR];
380 * Allocate space for a name. It first looks to see if it already
381 * has an appropriate sized entry, and if not allocates a new one.
393 np = strtblhdr[len / STRTBLINCR].next;
395 strtblhdr[len / STRTBLINCR].next = np->next;
398 cp = malloc((unsigned)allocsize(len));
400 panic("no space for string table\n");
402 (void) strcpy(cp, name);
407 * Free space for a name. The resulting entry is linked onto the
408 * appropriate free list.
413 struct strhdr *tp, *np;
415 tp = &strtblhdr[strlen(name) / STRTBLINCR];
416 np = (struct strhdr *)name;
422 * Useful quantities placed at the end of a dumped symbol table.
424 struct symtableheader {
427 int32_t entrytblsize;
435 * dump a snapshot of the symbol table
438 dumpsymtable(char *filename, long checkpt)
440 struct entry *ep, *tep;
442 struct entry temp, *tentry;
443 long mynum = 1, stroff = 0;
445 struct symtableheader hdr;
447 vprintf(stdout, "Checkpointing the restore\n");
450 if ((fd = fopen(filename, "w")) == NULL) {
451 fprintf(stderr, "fopen: %s\n", strerror(errno));
452 panic("cannot create save file %s for symbol table\n",
458 * Assign indices to each entry
459 * Write out the string entries
461 for (i = WINO; i <= maxino; i++) {
462 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
463 ep->e_index = mynum++;
464 (void) fwrite(ep->e_name, sizeof(char),
465 (int)allocsize(ep->e_namlen), fd);
469 * Convert pointers to indexes, and output
473 for (i = WINO; i <= maxino; i++) {
474 for (ep = lookupino(i); ep != NULL; ep = ep->e_links) {
475 memmove(tep, ep, (long)sizeof(struct entry));
476 tep->e_name = (char *)stroff;
477 stroff += allocsize(ep->e_namlen);
478 tep->e_parent = (struct entry *)ep->e_parent->e_index;
479 if (ep->e_links != NULL)
481 (struct entry *)ep->e_links->e_index;
482 if (ep->e_sibling != NULL)
484 (struct entry *)ep->e_sibling->e_index;
485 if (ep->e_entries != NULL)
487 (struct entry *)ep->e_entries->e_index;
488 if (ep->e_next != NULL)
490 (struct entry *)ep->e_next->e_index;
491 (void) fwrite((char *)tep, sizeof(struct entry), 1, fd);
495 * Convert entry pointers to indexes, and output
497 for (i = 0; i < entrytblsize; i++) {
498 if (entry[i] == NULL)
501 tentry = (struct entry *)entry[i]->e_index;
502 (void) fwrite((char *)&tentry, sizeof(struct entry *), 1, fd);
506 hdr.entrytblsize = entrytblsize;
507 hdr.stringsize = stroff;
508 hdr.dumptime = dumptime;
509 hdr.dumpdate = dumpdate;
511 (void) fwrite((char *)&hdr, sizeof(struct symtableheader), 1, fd);
513 fprintf(stderr, "fwrite: %s\n", strerror(errno));
514 panic("output error to file %s writing symbol table\n",
521 * Initialize a symbol table from a file
524 initsymtable(char *filename)
529 struct entry *baseep, *lep;
530 struct symtableheader hdr;
535 vprintf(stdout, "Initialize symbol table.\n");
536 if (filename == NULL) {
537 entrytblsize = maxino / HASHFACTOR;
538 entry = (struct entry **)
539 calloc((unsigned)entrytblsize, sizeof(struct entry *));
540 if (entry == (struct entry **)NULL)
541 panic("no memory for entry table\n");
542 ep = addentry(".", ROOTINO, NODE);
546 if ((fd = open(filename, O_RDONLY, 0)) < 0) {
547 fprintf(stderr, "open: %s\n", strerror(errno));
548 panic("cannot open symbol table file %s\n", filename);
550 if (fstat(fd, &stbuf) < 0) {
551 fprintf(stderr, "stat: %s\n", strerror(errno));
552 panic("cannot stat symbol table file %s\n", filename);
554 tblsize = stbuf.st_size - sizeof(struct symtableheader);
555 base = calloc(sizeof(char), (unsigned)tblsize);
557 panic("cannot allocate space for symbol table\n");
558 if (read(fd, base, (int)tblsize) < 0 ||
559 read(fd, (char *)&hdr, sizeof(struct symtableheader)) < 0) {
560 fprintf(stderr, "read: %s\n", strerror(errno));
561 panic("cannot read symbol table file %s\n", filename);
566 * For normal continuation, insure that we are using
567 * the next incremental tape
569 if (hdr.dumpdate != dumptime) {
570 if (hdr.dumpdate < dumptime)
571 fprintf(stderr, "Incremental tape too low\n");
573 fprintf(stderr, "Incremental tape too high\n");
579 * For restart, insure that we are using the same tape
581 curfile.action = SKIP;
582 dumptime = hdr.dumptime;
583 dumpdate = hdr.dumpdate;
585 newtapebuf(hdr.ntrec);
589 panic("initsymtable called from command %c\n", command);
593 entrytblsize = hdr.entrytblsize;
594 entry = (struct entry **)
595 (base + tblsize - (entrytblsize * sizeof(struct entry *)));
596 baseep = (struct entry *)(base + hdr.stringsize - sizeof(struct entry));
597 lep = (struct entry *)entry;
598 for (i = 0; i < entrytblsize; i++) {
599 if (entry[i] == NULL)
601 entry[i] = &baseep[(long)entry[i]];
603 for (ep = &baseep[1]; ep < lep; ep++) {
604 ep->e_name = base + (long)ep->e_name;
605 ep->e_parent = &baseep[(long)ep->e_parent];
606 if (ep->e_sibling != NULL)
607 ep->e_sibling = &baseep[(long)ep->e_sibling];
608 if (ep->e_links != NULL)
609 ep->e_links = &baseep[(long)ep->e_links];
610 if (ep->e_entries != NULL)
611 ep->e_entries = &baseep[(long)ep->e_entries];
612 if (ep->e_next != NULL)
613 ep->e_next = &baseep[(long)ep->e_next];