1/* $NetBSD: coda_namecache.c,v 1.26 2014/10/18 08:33:27 snj Exp $ */
2
3/*
4 *
5 * Coda: an Experimental Distributed File System
6 * Release 3.1
7 *
8 * Copyright (c) 1987-1998 Carnegie Mellon University
9 * All Rights Reserved
10 *
11 * Permission to use, copy, modify and distribute this software and its
12 * documentation is hereby granted, provided that both the copyright
13 * notice and this permission notice appear in all copies of the
14 * software, derivative works or modified versions, and any portions
15 * thereof, and that both notices appear in supporting documentation, and
16 * that credit is given to Carnegie Mellon University in all documents
17 * and publicity pertaining to direct or indirect use of this code or its
18 * derivatives.
19 *
20 * CODA IS AN EXPERIMENTAL SOFTWARE SYSTEM AND IS KNOWN TO HAVE BUGS,
21 * SOME OF WHICH MAY HAVE SERIOUS CONSEQUENCES. CARNEGIE MELLON ALLOWS
22 * FREE USE OF THIS SOFTWARE IN ITS "AS IS" CONDITION. CARNEGIE MELLON
23 * DISCLAIMS ANY LIABILITY OF ANY KIND FOR ANY DAMAGES WHATSOEVER
24 * RESULTING DIRECTLY OR INDIRECTLY FROM THE USE OF THIS SOFTWARE OR OF
25 * ANY DERIVATIVE WORK.
26 *
27 * Carnegie Mellon encourages users of this software to return any
28 * improvements or extensions that they make, and to grant Carnegie
29 * Mellon the rights to redistribute these changes without encumbrance.
30 *
31 * @(#) coda/coda_namecache.c,v 1.1.1.1 1998/08/29 21:26:45 rvb Exp $
32 */
33
34/*
35 * Mach Operating System
36 * Copyright (c) 1990 Carnegie-Mellon University
37 * Copyright (c) 1989 Carnegie-Mellon University
38 * All rights reserved. The CMU software License Agreement specifies
39 * the terms and conditions for use and redistribution.
40 */
41
42/*
43 * This code was written for the Coda file system at Carnegie Mellon University.
44 * Contributers include David Steere, James Kistler, and M. Satyanarayanan.
45 */
46
47/*
48 * This module contains the routines to implement the CODA name cache. The
49 * purpose of this cache is to reduce the cost of translating pathnames
50 * into Vice FIDs. Each entry in the cache contains the name of the file,
51 * the vnode (FID) of the parent directory, and the cred structure of the
52 * user accessing the file.
53 *
54 * The first time a file is accessed, it is looked up by the local Venus
55 * which first insures that the user has access to the file. In addition
56 * we are guaranteed that Venus will invalidate any name cache entries in
57 * case the user no longer should be able to access the file. For these
58 * reasons we do not need to keep access list information as well as a
59 * cred structure for each entry.
60 *
61 * The table can be accessed through the routines cnc_init(), cnc_enter(),
62 * cnc_lookup(), cnc_rmfidcred(), cnc_rmfid(), cnc_rmcred(), and cnc_purge().
63 * There are several other routines which aid in the implementation of the
64 * hash table.
65 */
66
67/*
68 * NOTES: rvb@cs
69 * 1. The name cache holds a reference to every vnode in it. Hence files can not be
70 * closed or made inactive until they are released.
71 * 2. coda_nc_name(cp) was added to get a name for a cnode pointer for debugging.
72 * 3. coda_nc_find() has debug code to detect when entries are stored with different
73 * credentials. We don't understand yet, if/how entries are NOT EQ but still
74 * EQUAL
75 * 4. I wonder if this name cache could be replace by the vnode name cache.
76 * The latter has no zapping functions, so probably not.
77 */
78
79#include <sys/cdefs.h>
80__KERNEL_RCSID(0, "$NetBSD: coda_namecache.c,v 1.26 2014/10/18 08:33:27 snj Exp $");
81
82#include <sys/param.h>
83#include <sys/errno.h>
84#include <sys/malloc.h>
85#include <sys/select.h>
86#include <sys/kauth.h>
87
88#include <coda/coda.h>
89#include <coda/cnode.h>
90#include <coda/coda_namecache.h>
91#include <coda/coda_subr.h>
92
93/*
94 * Declaration of the name cache data structure.
95 */
96
97int coda_nc_use = 1; /* Indicate use of CODA Name Cache */
98
99int coda_nc_size = CODA_NC_CACHESIZE; /* size of the cache */
100int coda_nc_hashsize = CODA_NC_HASHSIZE; /* size of the primary hash */
101
102struct coda_cache *coda_nc_heap; /* pointer to the cache entries */
103struct coda_hash *coda_nc_hash; /* hash table of cfscache pointers */
104struct coda_lru coda_nc_lru; /* head of lru chain */
105
106struct coda_nc_statistics coda_nc_stat; /* Keep various stats */
107
108/*
109 * for testing purposes
110 */
111int coda_nc_debug = 0;
112
113/*
114 * Entry points for the CODA Name Cache
115 */
116static struct coda_cache *
117coda_nc_find(struct cnode *dcp, const char *name, int namelen,
118 kauth_cred_t cred, int hash);
119static void
120coda_nc_remove(struct coda_cache *cncp, enum dc_status dcstat);
121
122/*
123 * Initialize the cache, the LRU structure and the Hash structure(s)
124 */
125
126#define TOTAL_CACHE_SIZE (sizeof(struct coda_cache) * coda_nc_size)
127#define TOTAL_HASH_SIZE (sizeof(struct coda_hash) * coda_nc_hashsize)
128
129int coda_nc_initialized = 0; /* Initially the cache has not been initialized */
130
131void
132coda_nc_init(void)
133{
134 int i;
135
136 /* zero the statistics structure */
137
138 memset(&coda_nc_stat, 0, (sizeof(struct coda_nc_statistics)));
139
140#ifdef CODA_VERBOSE
141 printf("CODA NAME CACHE: CACHE %d, HASH TBL %d\n", CODA_NC_CACHESIZE, CODA_NC_HASHSIZE);
142#endif
143 CODA_ALLOC(coda_nc_heap, struct coda_cache *, TOTAL_CACHE_SIZE);
144 CODA_ALLOC(coda_nc_hash, struct coda_hash *, TOTAL_HASH_SIZE);
145
146 memset(coda_nc_heap, 0, TOTAL_CACHE_SIZE);
147 memset(coda_nc_hash, 0, TOTAL_HASH_SIZE);
148
149 TAILQ_INIT(&coda_nc_lru.head);
150
151 for (i=0; i < coda_nc_size; i++) { /* initialize the heap */
152 TAILQ_INSERT_HEAD(&coda_nc_lru.head, &coda_nc_heap[i], lru);
153 }
154
155 for (i=0; i < coda_nc_hashsize; i++) { /* initialize the hashtable */
156 LIST_INIT(&coda_nc_hash[i].head);
157 }
158
159 coda_nc_initialized++;
160}
161
162/*
163 * Auxillary routines -- shouldn't be entry points
164 */
165
166static struct coda_cache *
167coda_nc_find(struct cnode *dcp, const char *name, int namelen,
168 kauth_cred_t cred, int hash)
169{
170 /*
171 * hash to find the appropriate bucket, look through the chain
172 * for the right entry (especially right cred, unless cred == 0)
173 */
174 struct coda_cache *cncp;
175 int count = 1;
176
177 CODA_NC_DEBUG(CODA_NC_FIND,
178 myprintf(("coda_nc_find(dcp %p, name %s, len %d, cred %p, hash %d\n",
179 dcp, name, namelen, cred, hash));)
180
181 LIST_FOREACH(cncp, &coda_nc_hash[hash].head, hash)
182 {
183
184 if ((CODA_NAMEMATCH(cncp, name, namelen, dcp)) &&
185 ((cred == 0) || (cncp->cred == cred)))
186 {
187 /* compare cr_uid instead */
188 coda_nc_stat.Search_len += count;
189 return(cncp);
190 }
191#ifdef DEBUG
192 else if (CODA_NAMEMATCH(cncp, name, namelen, dcp)) {
193 printf("coda_nc_find: name %s, new cred = %p, cred = %p\n",
194 name, cred, cncp->cred);
195 printf("nref %d, nuid %d, ngid %d // oref %d, ocred %d, ogid %d\n",
196 kauth_cred_getrefcnt(cred),
197 kauth_cred_geteuid(cred),
198 kauth_cred_getegid(cred),
199 kauth_cred_getrefcnt(cncp->cred),
200 kauth_cred_geteuid(cncp->cred),
201 kauth_cred_getegid(cncp->cred));
202 coda_print_cred(cred);
203 coda_print_cred(cncp->cred);
204 }
205#endif
206 count++;
207 }
208
209 return((struct coda_cache *)0);
210}
211
212/*
213 * Enter a new (dir cnode, name) pair into the cache, updating the
214 * LRU and Hash as needed.
215 */
216void
217coda_nc_enter(struct cnode *dcp, const char *name, int namelen,
218 kauth_cred_t cred, struct cnode *cp)
219{
220 struct coda_cache *cncp;
221 int hash;
222
223 if (coda_nc_use == 0) /* Cache is off */
224 return;
225
226 CODA_NC_DEBUG(CODA_NC_ENTER,
227 myprintf(("Enter: dcp %p cp %p name %s cred %p \n",
228 dcp, cp, name, cred)); )
229
230 if (namelen > CODA_NC_NAMELEN) {
231 CODA_NC_DEBUG(CODA_NC_ENTER,
232 myprintf(("long name enter %s\n",name));)
233 coda_nc_stat.long_name_enters++; /* record stats */
234 return;
235 }
236
237 hash = CODA_NC_HASH(name, namelen, dcp);
238 cncp = coda_nc_find(dcp, name, namelen, cred, hash);
239 if (cncp != (struct coda_cache *) 0) {
240 coda_nc_stat.dbl_enters++; /* duplicate entry */
241 return;
242 }
243
244 coda_nc_stat.enters++; /* record the enters statistic */
245
246 /* Grab the next element in the lru chain */
247 cncp = TAILQ_FIRST(&coda_nc_lru.head);
248 TAILQ_REMOVE(&coda_nc_lru.head, cncp, lru);
249
250 if (CODA_NC_VALID(cncp)) {
251 /* Seems really ugly, but we have to decrement the appropriate
252 hash bucket length here, so we have to find the hash bucket
253 */
254 coda_nc_hash[CODA_NC_HASH(cncp->name, cncp->namelen, cncp->dcp)].length--;
255
256 coda_nc_stat.lru_rm++; /* zapped a valid entry */
257 LIST_REMOVE(cncp, hash);
258 vrele(CTOV(cncp->dcp));
259 vrele(CTOV(cncp->cp));
260 kauth_cred_free(cncp->cred);
261 }
262
263 /*
264 * Put a hold on the current vnodes and fill in the cache entry.
265 */
266 vref(CTOV(cp));
267 vref(CTOV(dcp));
268 kauth_cred_hold(cred);
269 cncp->dcp = dcp;
270 cncp->cp = cp;
271 cncp->namelen = namelen;
272 cncp->cred = cred;
273
274 memcpy(cncp->name, name, (unsigned)namelen);
275
276 /* Insert into the lru and hash chains. */
277 TAILQ_INSERT_TAIL(&coda_nc_lru.head, cncp, lru);
278 LIST_INSERT_HEAD(&coda_nc_hash[hash].head, cncp, hash);
279 coda_nc_hash[hash].length++; /* Used for tuning */
280
281 CODA_NC_DEBUG(CODA_NC_PRINTCODA_NC, print_coda_nc(); )
282}
283
284/*
285 * Find the (dir cnode, name) pair in the cache, if its cred
286 * matches the input, return it, otherwise return 0
287 */
288struct cnode *
289coda_nc_lookup(struct cnode *dcp, const char *name, int namelen,
290 kauth_cred_t cred)
291{
292 int hash;
293 struct coda_cache *cncp;
294
295 if (coda_nc_use == 0) /* Cache is off */
296 return((struct cnode *) 0);
297
298 if (namelen > CODA_NC_NAMELEN) {
299 CODA_NC_DEBUG(CODA_NC_LOOKUP,
300 myprintf(("long name lookup %s\n",name));)
301 coda_nc_stat.long_name_lookups++; /* record stats */
302 return((struct cnode *) 0);
303 }
304
305 /* Use the hash function to locate the starting point,
306 then the search routine to go down the list looking for
307 the correct cred.
308 */
309
310 hash = CODA_NC_HASH(name, namelen, dcp);
311 cncp = coda_nc_find(dcp, name, namelen, cred, hash);
312 if (cncp == (struct coda_cache *) 0) {
313 coda_nc_stat.misses++; /* record miss */
314 return((struct cnode *) 0);
315 }
316
317 coda_nc_stat.hits++;
318
319 /* put this entry at the end of the LRU */
320 TAILQ_REMOVE(&coda_nc_lru.head, cncp, lru);
321 TAILQ_INSERT_TAIL(&coda_nc_lru.head, cncp, lru);
322
323 /* move it to the front of the hash chain */
324 /* don't need to change the hash bucket length */
325 LIST_REMOVE(cncp, hash);
326 LIST_INSERT_HEAD(&coda_nc_hash[hash].head, cncp, hash);
327
328 CODA_NC_DEBUG(CODA_NC_LOOKUP,
329 printf("lookup: dcp %p, name %s, cred %p = cp %p\n",
330 dcp, name, cred, cncp->cp); )
331
332 return(cncp->cp);
333}
334
335static void
336coda_nc_remove(struct coda_cache *cncp, enum dc_status dcstat)
337{
338 /*
339 * remove an entry -- vrele(cncp->dcp, cp), crfree(cred),
340 * remove it from its hash chain, and
341 * place it at the head of the lru list.
342 */
343 CODA_NC_DEBUG(CODA_NC_REMOVE,
344 myprintf(("coda_nc_remove %s from parent %s\n",
345 cncp->name, coda_f2s(&cncp->dcp->c_fid))); )
346
347
348 LIST_REMOVE(cncp, hash);
349 memset(&cncp->hash, 0, sizeof(cncp->hash));
350
351 if ((dcstat == IS_DOWNCALL) && (CTOV(cncp->dcp)->v_usecount == 1)) {
352 cncp->dcp->c_flags |= C_PURGING;
353 }
354 vrele(CTOV(cncp->dcp));
355
356 if ((dcstat == IS_DOWNCALL) && (CTOV(cncp->cp)->v_usecount == 1)) {
357 cncp->cp->c_flags |= C_PURGING;
358 }
359 vrele(CTOV(cncp->cp));
360
361 kauth_cred_free(cncp->cred);
362 memset(DATA_PART(cncp), 0, DATA_SIZE);
363
364 /* move the null entry to the front for reuse */
365 TAILQ_REMOVE(&coda_nc_lru.head, cncp, lru);
366 TAILQ_INSERT_HEAD(&coda_nc_lru.head, cncp, lru);
367}
368
369/*
370 * Remove all entries with a parent which has the input fid.
371 */
372void
373coda_nc_zapParentfid(CodaFid *fid, enum dc_status dcstat)
374{
375 /* To get to a specific fid, we might either have another hashing
376 function or do a sequential search through the cache for the
377 appropriate entries. The later may be acceptable since I don't
378 think callbacks or whatever Case 1 covers are frequent occurrences.
379 */
380 struct coda_cache *cncp, *ncncp;
381 int i;
382
383 if (coda_nc_use == 0) /* Cache is off */
384 return;
385
386 CODA_NC_DEBUG(CODA_NC_ZAPPFID,
387 myprintf(("ZapParent: fid %s\n", coda_f2s(fid))); )
388
389 coda_nc_stat.zapPfids++;
390
391 for (i = 0; i < coda_nc_hashsize; i++) {
392
393 /*
394 * Need to save the hash_next pointer in case we remove the
395 * entry. remove causes hash_next to point to itself.
396 */
397
398 ncncp = LIST_FIRST(&coda_nc_hash[i].head);
399 while ((cncp = ncncp) != NULL) {
400 ncncp = LIST_NEXT(cncp, hash);
401
402 if (coda_fid_eq(&(cncp->dcp->c_fid), fid)) {
403 coda_nc_hash[i].length--; /* Used for tuning */
404 coda_nc_remove(cncp, dcstat);
405 }
406 }
407 }
408}
409
410/*
411 * Remove all entries which have the same fid as the input
412 */
413void
414coda_nc_zapfid(CodaFid *fid, enum dc_status dcstat)
415{
416 /* See comment for zapParentfid. This routine will be used
417 if attributes are being cached.
418 */
419 struct coda_cache *cncp, *ncncp;
420 int i;
421
422 if (coda_nc_use == 0) /* Cache is off */
423 return;
424
425 CODA_NC_DEBUG(CODA_NC_ZAPFID,
426 myprintf(("Zapfid: fid %s\n", coda_f2s(fid))); )
427
428 coda_nc_stat.zapFids++;
429
430 for (i = 0; i < coda_nc_hashsize; i++) {
431
432 ncncp = LIST_FIRST(&coda_nc_hash[i].head);
433 while ((cncp = ncncp) != NULL) {
434 ncncp = LIST_NEXT(cncp, hash);
435
436 if (coda_fid_eq(&cncp->cp->c_fid, fid)) {
437 coda_nc_hash[i].length--; /* Used for tuning */
438 coda_nc_remove(cncp, dcstat);
439 }
440 }
441 }
442}
443
444/*
445 * Remove all entries which match the fid and the cred
446 */
447void
448coda_nc_zapvnode(CodaFid *fid, kauth_cred_t cred,
449 enum dc_status dcstat)
450{
451 /* See comment for zapfid. I don't think that one would ever
452 want to zap a file with a specific cred from the kernel.
453 We'll leave this one unimplemented.
454 */
455 if (coda_nc_use == 0) /* Cache is off */
456 return;
457
458 CODA_NC_DEBUG(CODA_NC_ZAPVNODE,
459 myprintf(("Zapvnode: fid %s cred %p\n",
460 coda_f2s(fid), cred)); )
461}
462
463/*
464 * Remove all entries which have the (dir vnode, name) pair
465 */
466void
467coda_nc_zapfile(struct cnode *dcp, const char *name, int namelen)
468{
469 /* use the hash function to locate the file, then zap all
470 entries of it regardless of the cred.
471 */
472 struct coda_cache *cncp;
473 int hash;
474
475 if (coda_nc_use == 0) /* Cache is off */
476 return;
477
478 CODA_NC_DEBUG(CODA_NC_ZAPFILE,
479 myprintf(("Zapfile: dcp %p name %s \n",
480 dcp, name)); )
481
482 if (namelen > CODA_NC_NAMELEN) {
483 coda_nc_stat.long_remove++; /* record stats */
484 return;
485 }
486
487 coda_nc_stat.zapFile++;
488
489 hash = CODA_NC_HASH(name, namelen, dcp);
490 cncp = coda_nc_find(dcp, name, namelen, 0, hash);
491
492 while (cncp) {
493 coda_nc_hash[hash].length--; /* Used for tuning */
494/* 1.3 */
495 coda_nc_remove(cncp, NOT_DOWNCALL);
496 cncp = coda_nc_find(dcp, name, namelen, 0, hash);
497 }
498}
499
500/*
501 * Remove all the entries for a particular user. Used when tokens expire.
502 * A user is determined by his/her effective user id (id_uid).
503 */
504void
505coda_nc_purge_user(uid_t uid, enum dc_status dcstat)
506{
507 /*
508 * I think the best approach is to go through the entire cache
509 * via HASH or whatever and zap all entries which match the
510 * input cred. Or just flush the whole cache. It might be
511 * best to go through on basis of LRU since cache will almost
512 * always be full and LRU is more straightforward.
513 */
514
515 struct coda_cache *cncp, *ncncp;
516 int hash;
517
518 if (coda_nc_use == 0) /* Cache is off */
519 return;
520
521 CODA_NC_DEBUG(CODA_NC_PURGEUSER,
522 myprintf(("ZapDude: uid %x\n", uid)); )
523 coda_nc_stat.zapUsers++;
524
525 ncncp = TAILQ_FIRST(&coda_nc_lru.head);
526 while ((cncp = ncncp) != NULL) {
527 ncncp = TAILQ_NEXT(cncp, lru);
528
529 if ((CODA_NC_VALID(cncp)) &&
530 (kauth_cred_geteuid(cncp->cred) == uid)) {
531 /* Seems really ugly, but we have to decrement the appropriate
532 hash bucket length here, so we have to find the hash bucket
533 */
534 hash = CODA_NC_HASH(cncp->name, cncp->namelen, cncp->dcp);
535 coda_nc_hash[hash].length--; /* For performance tuning */
536
537 coda_nc_remove(cncp, dcstat);
538 }
539 }
540}
541
542/*
543 * Flush the entire name cache. In response to a flush of the Venus cache.
544 */
545void
546coda_nc_flush(enum dc_status dcstat)
547{
548 /* One option is to deallocate the current name cache and
549 call init to start again. Or just deallocate, then rebuild.
550 Or again, we could just go through the array and zero the
551 appropriate fields.
552 */
553
554 /*
555 * Go through the whole lru chain and kill everything as we go.
556 * I don't use remove since that would rebuild the lru chain
557 * as it went and that seemed unneccesary.
558 */
559 struct coda_cache *cncp;
560 int i;
561
562 if (coda_nc_use == 0) /* Cache is off */
563 return;
564
565 coda_nc_stat.Flushes++;
566
567 TAILQ_FOREACH(cncp, &coda_nc_lru.head, lru) {
568 if (CODA_NC_VALID(cncp)) { /* only zero valid nodes */
569 LIST_REMOVE(cncp, hash);
570 memset(&cncp->hash, 0, sizeof(cncp->hash));
571
572 if ((dcstat == IS_DOWNCALL)
573 && (CTOV(cncp->dcp)->v_usecount == 1))
574 {
575 cncp->dcp->c_flags |= C_PURGING;
576 }
577 vrele(CTOV(cncp->dcp));
578
579 if (CTOV(cncp->cp)->v_iflag & VI_TEXT) {
580 if (coda_vmflush(cncp->cp))
581 CODADEBUG(CODA_FLUSH,
582 myprintf(("coda_nc_flush: %s busy\n",
583 coda_f2s(&cncp->cp->c_fid))); )
584 }
585
586 if ((dcstat == IS_DOWNCALL)
587 && (CTOV(cncp->cp)->v_usecount == 1))
588 {
589 cncp->cp->c_flags |= C_PURGING;
590 }
591 vrele(CTOV(cncp->cp));
592
593 kauth_cred_free(cncp->cred);
594 memset(DATA_PART(cncp), 0, DATA_SIZE);
595 }
596 }
597
598 for (i = 0; i < coda_nc_hashsize; i++)
599 coda_nc_hash[i].length = 0;
600}
601
602/*
603 * Debugging routines
604 */
605
606/*
607 * This routine should print out all the hash chains to the console.
608 */
609void
610print_coda_nc(void)
611{
612 int hash;
613 struct coda_cache *cncp;
614
615 for (hash = 0; hash < coda_nc_hashsize; hash++) {
616 myprintf(("\nhash %d\n",hash));
617
618 LIST_FOREACH(cncp, &coda_nc_hash[hash].head, hash) {
619 myprintf(("cp %p dcp %p cred %p name %s\n",
620 cncp->cp, cncp->dcp,
621 cncp->cred, cncp->name));
622 }
623 }
624}
625
626void
627coda_nc_gather_stats(void)
628{
629 int i, xmax = 0, sum = 0, temp, zeros = 0, ave, n;
630
631 for (i = 0; i < coda_nc_hashsize; i++) {
632 if (coda_nc_hash[i].length) {
633 sum += coda_nc_hash[i].length;
634 } else {
635 zeros++;
636 }
637
638 if (coda_nc_hash[i].length > xmax)
639 xmax = coda_nc_hash[i].length;
640 }
641
642 /*
643 * When computing the Arithmetic mean, only count slots which
644 * are not empty in the distribution.
645 */
646 coda_nc_stat.Sum_bucket_len = sum;
647 coda_nc_stat.Num_zero_len = zeros;
648 coda_nc_stat.Max_bucket_len = xmax;
649
650 if ((n = coda_nc_hashsize - zeros) > 0)
651 ave = sum / n;
652 else
653 ave = 0;
654
655 sum = 0;
656 for (i = 0; i < coda_nc_hashsize; i++) {
657 if (coda_nc_hash[i].length) {
658 temp = coda_nc_hash[i].length - ave;
659 sum += temp * temp;
660 }
661 }
662 coda_nc_stat.Sum2_bucket_len = sum;
663}
664
665/*
666 * The purpose of this routine is to allow the hash and cache sizes to be
667 * changed dynamically. This should only be used in controlled environments,
668 * it makes no effort to lock other users from accessing the cache while it
669 * is in an improper state (except by turning the cache off).
670 */
671int
672coda_nc_resize(int hashsize, int heapsize, enum dc_status dcstat)
673{
674 if ((hashsize % 2) || (heapsize % 2)) { /* Illegal hash or cache sizes */
675 return(EINVAL);
676 }
677
678 coda_nc_use = 0; /* Turn the cache off */
679
680 coda_nc_flush(dcstat); /* free any cnodes in the cache */
681
682 /* WARNING: free must happen *before* size is reset */
683 CODA_FREE(coda_nc_heap,TOTAL_CACHE_SIZE);
684 CODA_FREE(coda_nc_hash,TOTAL_HASH_SIZE);
685
686 coda_nc_hashsize = hashsize;
687 coda_nc_size = heapsize;
688
689 coda_nc_init(); /* Set up a cache with the new size */
690
691 coda_nc_use = 1; /* Turn the cache back on */
692 return(0);
693}
694
695char coda_nc_name_buf[CODA_MAXNAMLEN+1];
696
697void
698coda_nc_name(struct cnode *cp)
699{
700 struct coda_cache *cncp;
701 int i;
702
703 if (coda_nc_use == 0) /* Cache is off */
704 return;
705
706 for (i = 0; i < coda_nc_hashsize; i++) {
707
708 LIST_FOREACH(cncp, &coda_nc_hash[i].head, hash) {
709 if (cncp->cp == cp) {
710 memcpy(coda_nc_name_buf, cncp->name, cncp->namelen);
711 coda_nc_name_buf[cncp->namelen] = 0;
712 printf(" is %s (%p,%p)@%p",
713 coda_nc_name_buf, cncp->cp, cncp->dcp, cncp);
714 }
715
716 }
717 }
718}
719