1 /* $NetBSD: vfs_cache.c,v 1.61 2004/06/27 08:50:44 yamt Exp $ */ 2 3 /* 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)vfs_cache.c 8.3 (Berkeley) 8/22/94 32 */ 33 34 #include <sys/cdefs.h> 35 __KERNEL_RCSID(0, "$NetBSD: vfs_cache.c,v 1.61 2004/06/27 08:50:44 yamt Exp $"); 36 37 #include "opt_ddb.h" 38 #include "opt_revcache.h" 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/time.h> 43 #include <sys/mount.h> 44 #include <sys/vnode.h> 45 #include <sys/namei.h> 46 #include <sys/errno.h> 47 #include <sys/malloc.h> 48 #include <sys/pool.h> 49 #include <sys/lock.h> 50 51 /* 52 * Name caching works as follows: 53 * 54 * Names found by directory scans are retained in a cache 55 * for future reference. It is managed LRU, so frequently 56 * used names will hang around. Cache is indexed by hash value 57 * obtained from (dvp, name) where dvp refers to the directory 58 * containing name. 59 * 60 * For simplicity (and economy of storage), names longer than 61 * a maximum length of NCHNAMLEN are not cached; they occur 62 * infrequently in any case, and are almost never of interest. 63 * 64 * Upon reaching the last segment of a path, if the reference 65 * is for DELETE, or NOCACHE is set (rewrite), and the 66 * name is located in the cache, it will be dropped. 67 * The entry is dropped also when it was not possible to lock 68 * the cached vnode, either because vget() failed or the generation 69 * number has changed while waiting for the lock. 70 */ 71 72 /* 73 * Structures associated with name cacheing. 74 */ 75 LIST_HEAD(nchashhead, namecache) *nchashtbl; 76 u_long nchash; /* size of hash table - 1 */ 77 long numcache; /* number of cache entries allocated */ 78 #define NCHASH(cnp, dvp) \ 79 (((cnp)->cn_hash ^ ((uintptr_t)(dvp) >> 3)) & nchash) 80 81 LIST_HEAD(ncvhashhead, namecache) *ncvhashtbl; 82 u_long ncvhash; /* size of hash table - 1 */ 83 #define NCVHASH(vp) (((uintptr_t)(vp) >> 3) & ncvhash) 84 85 TAILQ_HEAD(, namecache) nclruhead; /* LRU chain */ 86 struct nchstats nchstats; /* cache effectiveness statistics */ 87 88 POOL_INIT(namecache_pool, sizeof(struct namecache), 0, 0, 0, "ncachepl", 89 &pool_allocator_nointr); 90 91 MALLOC_DEFINE(M_CACHE, "namecache", "Dynamically allocated cache entries"); 92 93 int doingcache = 1; /* 1 => enable the cache */ 94 95 /* A single lock to protect cache insertion, removal and lookup */ 96 static struct simplelock namecache_slock = SIMPLELOCK_INITIALIZER; 97 98 static void cache_remove(struct namecache *); 99 static void cache_free(struct namecache *); 100 static __inline struct namecache *cache_lookup_entry( 101 const struct vnode *, const struct componentname *); 102 103 static void 104 cache_remove(struct namecache *ncp) 105 { 106 107 LOCK_ASSERT(simple_lock_held(&namecache_slock)); 108 109 ncp->nc_dvp = NULL; 110 ncp->nc_vp = NULL; 111 112 TAILQ_REMOVE(&nclruhead, ncp, nc_lru); 113 if (ncp->nc_hash.le_prev != NULL) { 114 LIST_REMOVE(ncp, nc_hash); 115 ncp->nc_hash.le_prev = NULL; 116 } 117 if (ncp->nc_vhash.le_prev != NULL) { 118 LIST_REMOVE(ncp, nc_vhash); 119 ncp->nc_vhash.le_prev = NULL; 120 } 121 if (ncp->nc_vlist.le_prev != NULL) { 122 LIST_REMOVE(ncp, nc_vlist); 123 ncp->nc_vlist.le_prev = NULL; 124 } 125 if (ncp->nc_dvlist.le_prev != NULL) { 126 LIST_REMOVE(ncp, nc_dvlist); 127 ncp->nc_dvlist.le_prev = NULL; 128 } 129 } 130 131 static void 132 cache_free(struct namecache *ncp) 133 { 134 135 pool_put(&namecache_pool, ncp); 136 numcache--; 137 } 138 139 static __inline struct namecache * 140 cache_lookup_entry(const struct vnode *dvp, const struct componentname *cnp) 141 { 142 struct nchashhead *ncpp; 143 struct namecache *ncp; 144 145 LOCK_ASSERT(simple_lock_held(&namecache_slock)); 146 147 ncpp = &nchashtbl[NCHASH(cnp, dvp)]; 148 149 LIST_FOREACH(ncp, ncpp, nc_hash) { 150 if (ncp->nc_dvp == dvp && 151 ncp->nc_nlen == cnp->cn_namelen && 152 !memcmp(ncp->nc_name, cnp->cn_nameptr, (u_int)ncp->nc_nlen)) 153 break; 154 } 155 156 return ncp; 157 } 158 159 /* 160 * Look for a the name in the cache. We don't do this 161 * if the segment name is long, simply so the cache can avoid 162 * holding long names (which would either waste space, or 163 * add greatly to the complexity). 164 * 165 * Lookup is called with ni_dvp pointing to the directory to search, 166 * ni_ptr pointing to the name of the entry being sought, ni_namelen 167 * tells the length of the name, and ni_hash contains a hash of 168 * the name. If the lookup succeeds, the vnode is locked, stored in ni_vp 169 * and a status of zero is returned. If the locking fails for whatever 170 * reason, the vnode is unlocked and the error is returned to caller. 171 * If the lookup determines that the name does not exist (negative cacheing), 172 * a status of ENOENT is returned. If the lookup fails, a status of -1 173 * is returned. 174 */ 175 int 176 cache_lookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp) 177 { 178 struct namecache *ncp; 179 struct vnode *vp; 180 int error; 181 182 if (!doingcache) { 183 cnp->cn_flags &= ~MAKEENTRY; 184 *vpp = NULL; 185 return (-1); 186 } 187 188 if (cnp->cn_namelen > NCHNAMLEN) { 189 /* XXXSMP - updating stats without lock; do we care? */ 190 nchstats.ncs_long++; 191 cnp->cn_flags &= ~MAKEENTRY; 192 goto fail; 193 } 194 simple_lock(&namecache_slock); 195 ncp = cache_lookup_entry(dvp, cnp); 196 if (ncp == NULL) { 197 nchstats.ncs_miss++; 198 goto fail_wlock; 199 } 200 if ((cnp->cn_flags & MAKEENTRY) == 0) { 201 nchstats.ncs_badhits++; 202 goto remove; 203 } else if (ncp->nc_vp == NULL) { 204 /* 205 * Restore the ISWHITEOUT flag saved earlier. 206 */ 207 cnp->cn_flags |= ncp->nc_flags; 208 if (cnp->cn_nameiop != CREATE || 209 (cnp->cn_flags & ISLASTCN) == 0) { 210 nchstats.ncs_neghits++; 211 /* 212 * Move this slot to end of LRU chain, 213 * if not already there. 214 */ 215 if (TAILQ_NEXT(ncp, nc_lru) != 0) { 216 TAILQ_REMOVE(&nclruhead, ncp, nc_lru); 217 TAILQ_INSERT_TAIL(&nclruhead, ncp, nc_lru); 218 } 219 simple_unlock(&namecache_slock); 220 return (ENOENT); 221 } else { 222 nchstats.ncs_badhits++; 223 goto remove; 224 } 225 } 226 227 vp = ncp->nc_vp; 228 229 /* 230 * Move this slot to end of LRU chain, if not already there. 231 */ 232 if (TAILQ_NEXT(ncp, nc_lru) != 0) { 233 TAILQ_REMOVE(&nclruhead, ncp, nc_lru); 234 TAILQ_INSERT_TAIL(&nclruhead, ncp, nc_lru); 235 } 236 237 error = vget(vp, LK_NOWAIT); 238 239 /* Release the name cache mutex while we get reference to the vnode */ 240 simple_unlock(&namecache_slock); 241 242 #ifdef DEBUG 243 /* 244 * since we released namecache_slock, 245 * we can't use this pointer any more. 246 */ 247 ncp = NULL; 248 #endif /* DEBUG */ 249 250 if (error) { 251 KASSERT(error == EBUSY); 252 /* 253 * this vnode is being cleaned out. 254 */ 255 nchstats.ncs_falsehits++; /* XXX badhits? */ 256 goto fail; 257 } 258 259 if (vp == dvp) { /* lookup on "." */ 260 error = 0; 261 } else if (cnp->cn_flags & ISDOTDOT) { 262 VOP_UNLOCK(dvp, 0); 263 cnp->cn_flags |= PDIRUNLOCK; 264 error = vn_lock(vp, LK_EXCLUSIVE); 265 /* 266 * If the above vn_lock() succeeded and both LOCKPARENT and 267 * ISLASTCN is set, lock the directory vnode as well. 268 */ 269 if (!error && (~cnp->cn_flags & (LOCKPARENT|ISLASTCN)) == 0) { 270 if ((error = vn_lock(dvp, LK_EXCLUSIVE)) != 0) { 271 vput(vp); 272 return (error); 273 } 274 cnp->cn_flags &= ~PDIRUNLOCK; 275 } 276 } else { 277 error = vn_lock(vp, LK_EXCLUSIVE); 278 /* 279 * If the above vn_lock() failed or either of LOCKPARENT or 280 * ISLASTCN is set, unlock the directory vnode. 281 */ 282 if (error || (~cnp->cn_flags & (LOCKPARENT|ISLASTCN)) != 0) { 283 VOP_UNLOCK(dvp, 0); 284 cnp->cn_flags |= PDIRUNLOCK; 285 } 286 } 287 288 /* 289 * Check that the lock succeeded. 290 */ 291 if (error) { 292 /* XXXSMP - updating stats without lock; do we care? */ 293 nchstats.ncs_badhits++; 294 295 /* 296 * The parent needs to be locked when we return to VOP_LOOKUP(). 297 * The `.' case here should be extremely rare (if it can happen 298 * at all), so we don't bother optimizing out the unlock/relock. 299 */ 300 if (vp == dvp || 301 error || (~cnp->cn_flags & (LOCKPARENT|ISLASTCN)) != 0) { 302 if ((error = vn_lock(dvp, LK_EXCLUSIVE)) != 0) 303 return (error); 304 cnp->cn_flags &= ~PDIRUNLOCK; 305 } 306 *vpp = NULL; 307 return (-1); 308 } 309 310 /* XXXSMP - updating stats without lock; do we care? */ 311 nchstats.ncs_goodhits++; 312 *vpp = vp; 313 return (0); 314 315 remove: 316 /* 317 * Last component and we are renaming or deleting, 318 * the cache entry is invalid, or otherwise don't 319 * want cache entry to exist. 320 */ 321 cache_remove(ncp); 322 cache_free(ncp); 323 324 fail_wlock: 325 simple_unlock(&namecache_slock); 326 fail: 327 *vpp = NULL; 328 return (-1); 329 } 330 331 int 332 cache_lookup_raw(struct vnode *dvp, struct vnode **vpp, 333 struct componentname *cnp) 334 { 335 struct namecache *ncp; 336 struct vnode *vp; 337 int error; 338 339 if (!doingcache) { 340 cnp->cn_flags &= ~MAKEENTRY; 341 *vpp = NULL; 342 return (-1); 343 } 344 345 if (cnp->cn_namelen > NCHNAMLEN) { 346 /* XXXSMP - updating stats without lock; do we care? */ 347 nchstats.ncs_long++; 348 cnp->cn_flags &= ~MAKEENTRY; 349 goto fail; 350 } 351 simple_lock(&namecache_slock); 352 ncp = cache_lookup_entry(dvp, cnp); 353 if (ncp == NULL) { 354 nchstats.ncs_miss++; 355 goto fail_wlock; 356 } 357 /* 358 * Move this slot to end of LRU chain, 359 * if not already there. 360 */ 361 if (TAILQ_NEXT(ncp, nc_lru) != 0) { 362 TAILQ_REMOVE(&nclruhead, ncp, nc_lru); 363 TAILQ_INSERT_TAIL(&nclruhead, ncp, nc_lru); 364 } 365 366 vp = ncp->nc_vp; 367 if (vp == NULL) { 368 /* 369 * Restore the ISWHITEOUT flag saved earlier. 370 */ 371 cnp->cn_flags |= ncp->nc_flags; 372 nchstats.ncs_neghits++; 373 simple_unlock(&namecache_slock); 374 return (ENOENT); 375 } 376 377 error = vget(vp, LK_NOWAIT); 378 379 /* Release the name cache mutex while we get reference to the vnode */ 380 simple_unlock(&namecache_slock); 381 382 if (error) { 383 KASSERT(error == EBUSY); 384 /* 385 * this vnode is being cleaned out. 386 */ 387 nchstats.ncs_falsehits++; /* XXX badhits? */ 388 goto fail; 389 } 390 391 *vpp = vp; 392 393 return 0; 394 395 fail_wlock: 396 simple_unlock(&namecache_slock); 397 fail: 398 *vpp = NULL; 399 return -1; 400 } 401 402 /* 403 * Scan cache looking for name of directory entry pointing at vp. 404 * 405 * Fill in dvpp. 406 * 407 * If bufp is non-NULL, also place the name in the buffer which starts 408 * at bufp, immediately before *bpp, and move bpp backwards to point 409 * at the start of it. (Yes, this is a little baroque, but it's done 410 * this way to cater to the whims of getcwd). 411 * 412 * Returns 0 on success, -1 on cache miss, positive errno on failure. 413 */ 414 int 415 cache_revlookup(struct vnode *vp, struct vnode **dvpp, char **bpp, char *bufp) 416 { 417 struct namecache *ncp; 418 struct vnode *dvp; 419 struct ncvhashhead *nvcpp; 420 char *bp; 421 422 if (!doingcache) 423 goto out; 424 425 nvcpp = &ncvhashtbl[NCVHASH(vp)]; 426 427 simple_lock(&namecache_slock); 428 LIST_FOREACH(ncp, nvcpp, nc_vhash) { 429 if (ncp->nc_vp == vp && 430 (dvp = ncp->nc_dvp) != NULL && 431 dvp != vp) { /* avoid pesky . entries.. */ 432 433 #ifdef DIAGNOSTIC 434 if (ncp->nc_nlen == 1 && 435 ncp->nc_name[0] == '.') 436 panic("cache_revlookup: found entry for ."); 437 438 if (ncp->nc_nlen == 2 && 439 ncp->nc_name[0] == '.' && 440 ncp->nc_name[1] == '.') 441 panic("cache_revlookup: found entry for .."); 442 #endif 443 nchstats.ncs_revhits++; 444 445 if (bufp) { 446 bp = *bpp; 447 bp -= ncp->nc_nlen; 448 if (bp <= bufp) { 449 *dvpp = NULL; 450 simple_unlock(&namecache_slock); 451 return (ERANGE); 452 } 453 memcpy(bp, ncp->nc_name, ncp->nc_nlen); 454 *bpp = bp; 455 } 456 457 /* XXX MP: how do we know dvp won't evaporate? */ 458 *dvpp = dvp; 459 simple_unlock(&namecache_slock); 460 return (0); 461 } 462 } 463 nchstats.ncs_revmiss++; 464 simple_unlock(&namecache_slock); 465 out: 466 *dvpp = NULL; 467 return (-1); 468 } 469 470 /* 471 * Add an entry to the cache 472 */ 473 void 474 cache_enter(struct vnode *dvp, struct vnode *vp, struct componentname *cnp) 475 { 476 struct namecache *ncp; 477 struct namecache *oncp; 478 struct nchashhead *ncpp; 479 struct ncvhashhead *nvcpp; 480 481 #ifdef DIAGNOSTIC 482 if (cnp->cn_namelen > NCHNAMLEN) 483 panic("cache_enter: name too long"); 484 #endif 485 if (!doingcache) 486 return; 487 /* 488 * Free the cache slot at head of lru chain. 489 */ 490 simple_lock(&namecache_slock); 491 492 if (numcache < numvnodes) { 493 numcache++; 494 simple_unlock(&namecache_slock); 495 ncp = pool_get(&namecache_pool, PR_WAITOK); 496 memset(ncp, 0, sizeof(*ncp)); 497 simple_lock(&namecache_slock); 498 } else if ((ncp = TAILQ_FIRST(&nclruhead)) != NULL) { 499 cache_remove(ncp); 500 } else { 501 simple_unlock(&namecache_slock); 502 return; 503 } 504 505 /* 506 * Concurrent lookups in the same directory may race for a 507 * cache entry. if there's a duplicated entry, free it. 508 */ 509 oncp = cache_lookup_entry(dvp, cnp); 510 if (oncp) { 511 cache_remove(oncp); 512 cache_free(oncp); 513 } 514 KASSERT(cache_lookup_entry(dvp, cnp) == NULL); 515 516 /* Grab the vnode we just found. */ 517 ncp->nc_vp = vp; 518 if (vp == NULL) { 519 /* 520 * For negative hits, save the ISWHITEOUT flag so we can 521 * restore it later when the cache entry is used again. 522 */ 523 ncp->nc_flags = cnp->cn_flags & ISWHITEOUT; 524 } 525 /* Fill in cache info. */ 526 ncp->nc_dvp = dvp; 527 LIST_INSERT_HEAD(&dvp->v_dnclist, ncp, nc_dvlist); 528 if (vp) 529 LIST_INSERT_HEAD(&vp->v_nclist, ncp, nc_vlist); 530 ncp->nc_nlen = cnp->cn_namelen; 531 memcpy(ncp->nc_name, cnp->cn_nameptr, (unsigned)ncp->nc_nlen); 532 TAILQ_INSERT_TAIL(&nclruhead, ncp, nc_lru); 533 ncpp = &nchashtbl[NCHASH(cnp, dvp)]; 534 LIST_INSERT_HEAD(ncpp, ncp, nc_hash); 535 536 ncp->nc_vhash.le_prev = NULL; 537 ncp->nc_vhash.le_next = NULL; 538 539 /* 540 * Create reverse-cache entries (used in getcwd) for directories. 541 */ 542 if (vp != NULL && 543 vp != dvp && 544 #ifndef NAMECACHE_ENTER_REVERSE 545 vp->v_type == VDIR && 546 #endif 547 (ncp->nc_nlen > 2 || 548 (ncp->nc_nlen > 1 && ncp->nc_name[1] != '.') || 549 (/* ncp->nc_nlen > 0 && */ ncp->nc_name[0] != '.'))) { 550 nvcpp = &ncvhashtbl[NCVHASH(vp)]; 551 LIST_INSERT_HEAD(nvcpp, ncp, nc_vhash); 552 } 553 simple_unlock(&namecache_slock); 554 } 555 556 /* 557 * Name cache initialization, from vfs_init() when we are booting 558 */ 559 void 560 nchinit(void) 561 { 562 563 TAILQ_INIT(&nclruhead); 564 nchashtbl = 565 hashinit(desiredvnodes, HASH_LIST, M_CACHE, M_WAITOK, &nchash); 566 ncvhashtbl = 567 #ifdef NAMECACHE_ENTER_REVERSE 568 hashinit(desiredvnodes, HASH_LIST, M_CACHE, M_WAITOK, &ncvhash); 569 #else 570 hashinit(desiredvnodes/8, HASH_LIST, M_CACHE, M_WAITOK, &ncvhash); 571 #endif 572 } 573 574 /* 575 * Name cache reinitialization, for when the maximum number of vnodes increases. 576 */ 577 void 578 nchreinit(void) 579 { 580 struct namecache *ncp; 581 struct nchashhead *oldhash1, *hash1; 582 struct ncvhashhead *oldhash2, *hash2; 583 u_long i, oldmask1, oldmask2, mask1, mask2; 584 585 hash1 = hashinit(desiredvnodes, HASH_LIST, M_CACHE, M_WAITOK, &mask1); 586 hash2 = 587 #ifdef NAMECACHE_ENTER_REVERSE 588 hashinit(desiredvnodes, HASH_LIST, M_CACHE, M_WAITOK, &mask2); 589 #else 590 hashinit(desiredvnodes/8, HASH_LIST, M_CACHE, M_WAITOK, &mask2); 591 #endif 592 simple_lock(&namecache_slock); 593 oldhash1 = nchashtbl; 594 oldmask1 = nchash; 595 nchashtbl = hash1; 596 nchash = mask1; 597 oldhash2 = ncvhashtbl; 598 oldmask2 = ncvhash; 599 ncvhashtbl = hash2; 600 ncvhash = mask2; 601 for (i = 0; i <= oldmask1; i++) { 602 while ((ncp = LIST_FIRST(&oldhash1[i])) != NULL) { 603 LIST_REMOVE(ncp, nc_hash); 604 ncp->nc_hash.le_prev = NULL; 605 } 606 } 607 for (i = 0; i <= oldmask2; i++) { 608 while ((ncp = LIST_FIRST(&oldhash2[i])) != NULL) { 609 LIST_REMOVE(ncp, nc_vhash); 610 ncp->nc_vhash.le_prev = NULL; 611 } 612 } 613 simple_unlock(&namecache_slock); 614 hashdone(oldhash1, M_CACHE); 615 hashdone(oldhash2, M_CACHE); 616 } 617 618 /* 619 * Cache flush, a particular vnode; called when a vnode is renamed to 620 * hide entries that would now be invalid 621 */ 622 void 623 cache_purge1(struct vnode *vp, const struct componentname *cnp, int flags) 624 { 625 struct namecache *ncp, *ncnext; 626 627 simple_lock(&namecache_slock); 628 if (flags & PURGE_PARENTS) { 629 for (ncp = LIST_FIRST(&vp->v_nclist); ncp != NULL; 630 ncp = ncnext) { 631 ncnext = LIST_NEXT(ncp, nc_vlist); 632 cache_remove(ncp); 633 cache_free(ncp); 634 } 635 } 636 if (flags & PURGE_CHILDREN) { 637 for (ncp = LIST_FIRST(&vp->v_dnclist); ncp != NULL; 638 ncp = ncnext) { 639 ncnext = LIST_NEXT(ncp, nc_dvlist); 640 cache_remove(ncp); 641 cache_free(ncp); 642 } 643 } 644 if (cnp != NULL) { 645 ncp = cache_lookup_entry(vp, cnp); 646 if (ncp) { 647 cache_remove(ncp); 648 cache_free(ncp); 649 } 650 } 651 simple_unlock(&namecache_slock); 652 } 653 654 /* 655 * Cache flush, a whole filesystem; called when filesys is umounted to 656 * remove entries that would now be invalid. 657 */ 658 void 659 cache_purgevfs(struct mount *mp) 660 { 661 struct namecache *ncp, *nxtcp; 662 663 simple_lock(&namecache_slock); 664 for (ncp = TAILQ_FIRST(&nclruhead); ncp != NULL; ncp = nxtcp) { 665 nxtcp = TAILQ_NEXT(ncp, nc_lru); 666 if (ncp->nc_dvp == NULL || ncp->nc_dvp->v_mount != mp) { 667 continue; 668 } 669 /* Free the resources we had. */ 670 cache_remove(ncp); 671 cache_free(ncp); 672 } 673 simple_unlock(&namecache_slock); 674 } 675 676 #ifdef DDB 677 void 678 namecache_print(struct vnode *vp, void (*pr)(const char *, ...)) 679 { 680 struct vnode *dvp = NULL; 681 struct namecache *ncp; 682 683 TAILQ_FOREACH(ncp, &nclruhead, nc_lru) { 684 if (ncp->nc_vp == vp) { 685 (*pr)("name %.*s\n", ncp->nc_nlen, ncp->nc_name); 686 dvp = ncp->nc_dvp; 687 } 688 } 689 if (dvp == NULL) { 690 (*pr)("name not found\n"); 691 return; 692 } 693 vp = dvp; 694 TAILQ_FOREACH(ncp, &nclruhead, nc_lru) { 695 if (ncp->nc_vp == vp) { 696 (*pr)("parent %.*s\n", ncp->nc_nlen, ncp->nc_name); 697 } 698 } 699 } 700 #endif 701