1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Rick Macklem at The University of Guelph. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)nfs_node.c 8.6 (Berkeley) 5/22/95 33 * $FreeBSD: src/sys/nfs/nfs_node.c,v 1.36.2.3 2002/01/05 22:25:04 dillon Exp $ 34 */ 35 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/proc.h> 40 #include <sys/mount.h> 41 #include <sys/namei.h> 42 #include <sys/vnode.h> 43 #include <sys/malloc.h> 44 #include <sys/kernel.h> 45 #include <sys/fnv_hash.h> 46 #include <sys/objcache.h> 47 48 #include "rpcv2.h" 49 #include "nfsproto.h" 50 #include "nfs.h" 51 #include "nfsmount.h" 52 #include "nfsnode.h" 53 54 static MALLOC_DEFINE(M_NFSNODE, "NFS node", "NFS node"); 55 56 static struct lwkt_token nfsnhash_token = 57 LWKT_TOKEN_INITIALIZER(nfsnhash_token); 58 static struct lock nfsnhash_lock; 59 __read_mostly static struct objcache *nfsnode_objcache; 60 __read_mostly static LIST_HEAD(nfsnodehashhead, nfsnode) *nfsnodehashtbl; 61 __read_mostly static u_long nfsnodehash; 62 63 #define TRUE 1 64 #define FALSE 0 65 66 #define NFSNOHASH(fhsum) (&nfsnodehashtbl[(fhsum) & nfsnodehash]) 67 68 /* 69 * Initialize hash links for nfsnodes 70 * and build nfsnode free list. 71 */ 72 void 73 nfs_nhinit(void) 74 { 75 int hsize = vfs_inodehashsize(); 76 77 nfsnode_objcache = objcache_create_simple(M_NFSNODE, 78 sizeof(struct nfsnode)); 79 nfsnodehashtbl = hashinit(hsize, M_NFSHASH, &nfsnodehash); 80 lockinit(&nfsnhash_lock, "nfsnht", 0, 0); 81 } 82 83 void 84 nfs_nhdestroy(void) 85 { 86 hashdestroy(nfsnodehashtbl, M_NFSHASH, nfsnodehash); 87 objcache_destroy(nfsnode_objcache); 88 } 89 90 /* 91 * Look up a vnode/nfsnode by file handle. 92 * Callers must check for mount points!! 93 * In all cases, a pointer to a 94 * nfsnode structure is returned. 95 */ 96 97 int 98 nfs_nget(struct mount *mntp, nfsfh_t *fhp, int fhsize, struct nfsnode **npp, 99 struct vnode *notvp) 100 { 101 struct nfsnode *np, *np2; 102 struct nfsnodehashhead *nhpp; 103 struct vnode *vp; 104 int error; 105 int lkflags; 106 struct nfsmount *nmp; 107 108 /* 109 * Calculate nfs mount point and figure out whether the rslock should 110 * be interruptable or not. 111 */ 112 nmp = VFSTONFS(mntp); 113 if (nmp->nm_flag & NFSMNT_INT) 114 lkflags = LK_PCATCH; 115 else 116 lkflags = 0; 117 118 lwkt_gettoken(&nfsnhash_token); 119 120 retry: 121 nhpp = NFSNOHASH(fnv_32_buf(fhp->fh_bytes, fhsize, FNV1_32_INIT)); 122 loop: 123 LIST_FOREACH(np, nhpp, n_hash) { 124 if (mntp != NFSTOV(np)->v_mount || np->n_fhsize != fhsize || 125 bcmp((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize)) { 126 continue; 127 } 128 vp = NFSTOV(np); 129 if (vp == notvp) { 130 kprintf("nfs warning: client-client collision " 131 "during rename/link/softlink\n"); 132 *npp = NULL; 133 lwkt_reltoken(&nfsnhash_token); 134 return (ESTALE); 135 } 136 if (vget(vp, LK_EXCLUSIVE)) 137 goto loop; 138 LIST_FOREACH(np, nhpp, n_hash) { 139 if (mntp == NFSTOV(np)->v_mount && 140 np->n_fhsize == fhsize && 141 bcmp((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize) == 0 142 ) { 143 break; 144 } 145 } 146 if (np == NULL || NFSTOV(np) != vp) { 147 vput(vp); 148 goto loop; 149 } 150 *npp = np; 151 lwkt_reltoken(&nfsnhash_token); 152 return(0); 153 } 154 155 /* 156 * Obtain a lock to prevent a race condition if the getnewvnode() 157 * or MALLOC() below happens to block. 158 */ 159 if (lockmgr(&nfsnhash_lock, LK_EXCLUSIVE | LK_SLEEPFAIL)) 160 goto loop; 161 162 /* 163 * Allocate before getnewvnode since doing so afterward 164 * might cause a bogus v_data pointer to get dereferenced 165 * elsewhere if objcache should block. 166 */ 167 np = objcache_get(nfsnode_objcache, M_WAITOK); 168 169 error = getnewvnode(VT_NFS, mntp, &vp, 0, 0); 170 if (error) { 171 lockmgr(&nfsnhash_lock, LK_RELEASE); 172 *npp = NULL; 173 objcache_put(nfsnode_objcache, np); 174 lwkt_reltoken(&nfsnhash_token); 175 return (error); 176 } 177 178 /* 179 * Initialize most of (np). 180 */ 181 bzero(np, sizeof (*np)); 182 if (fhsize > NFS_SMALLFH) { 183 np->n_fhp = kmalloc(fhsize, M_NFSBIGFH, M_WAITOK); 184 } else { 185 np->n_fhp = &np->n_fh; 186 } 187 bcopy((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize); 188 np->n_fhsize = fhsize; 189 lockinit(&np->n_rslock, "nfrslk", 0, lkflags); 190 191 /* 192 * Validate that we did not race another nfs_nget() due to blocking 193 * here and there. 194 */ 195 for (np2 = nhpp->lh_first; np2 != NULL; np2 = np2->n_hash.le_next) { 196 if (mntp != NFSTOV(np2)->v_mount || np2->n_fhsize != fhsize || 197 bcmp((caddr_t)fhp, (caddr_t)np2->n_fhp, fhsize)) { 198 continue; 199 } 200 vx_put(vp); 201 lockmgr(&nfsnhash_lock, LK_RELEASE); 202 203 if (np->n_fhsize > NFS_SMALLFH) 204 kfree((caddr_t)np->n_fhp, M_NFSBIGFH); 205 np->n_fhp = NULL; 206 objcache_put(nfsnode_objcache, np); 207 goto retry; 208 } 209 210 /* 211 * Finish connecting up (np, vp) and insert the nfsnode in the 212 * hash for its new file handle. 213 * 214 * nvp is locked & refd so effectively so is np. 215 */ 216 np->n_vnode = vp; 217 vp->v_data = np; 218 LIST_INSERT_HEAD(nhpp, np, n_hash); 219 *npp = np; 220 lockmgr(&nfsnhash_lock, LK_RELEASE); 221 lwkt_reltoken(&nfsnhash_token); 222 223 return (0); 224 } 225 226 /* 227 * Nonblocking version of nfs_nget() 228 */ 229 int 230 nfs_nget_nonblock(struct mount *mntp, nfsfh_t *fhp, int fhsize, 231 struct nfsnode **npp, struct vnode *notvp) 232 { 233 struct nfsnode *np, *np2; 234 struct nfsnodehashhead *nhpp; 235 struct vnode *vp; 236 int error; 237 int lkflags; 238 struct nfsmount *nmp; 239 240 /* 241 * Calculate nfs mount point and figure out whether the rslock should 242 * be interruptable or not. 243 */ 244 nmp = VFSTONFS(mntp); 245 if (nmp->nm_flag & NFSMNT_INT) 246 lkflags = LK_PCATCH; 247 else 248 lkflags = 0; 249 vp = NULL; 250 *npp = NULL; 251 252 lwkt_gettoken(&nfsnhash_token); 253 254 retry: 255 nhpp = NFSNOHASH(fnv_32_buf(fhp->fh_bytes, fhsize, FNV1_32_INIT)); 256 loop: 257 LIST_FOREACH(np, nhpp, n_hash) { 258 if (mntp != NFSTOV(np)->v_mount || np->n_fhsize != fhsize || 259 bcmp((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize)) { 260 continue; 261 } 262 if (vp == NULL) { 263 vp = NFSTOV(np); 264 if (vp == notvp) { 265 kprintf("nfs warning: client-client collision " 266 "during rename/link/softlink\n"); 267 error = ESTALE; 268 goto fail; 269 } 270 if (vget(vp, LK_EXCLUSIVE | LK_NOWAIT)) { 271 error = EWOULDBLOCK; 272 goto fail; 273 } 274 goto loop; 275 } 276 if (NFSTOV(np) != vp) { 277 vput(vp); 278 goto loop; 279 } 280 *npp = np; 281 lwkt_reltoken(&nfsnhash_token); 282 return(0); 283 } 284 285 /* 286 * Not found. If we raced and had acquired a vp we have to release 287 * it here. 288 */ 289 if (vp) { 290 vput(vp); 291 vp = NULL; 292 } 293 294 /* 295 * Obtain a lock to prevent a race condition if the getnewvnode() 296 * or MALLOC() below happens to block. 297 */ 298 if (lockmgr(&nfsnhash_lock, LK_EXCLUSIVE | LK_SLEEPFAIL)) 299 goto loop; 300 301 /* 302 * Entry not found, allocate a new entry. 303 * 304 * Allocate before getnewvnode since doing so afterward 305 * might cause a bogus v_data pointer to get dereferenced 306 * elsewhere if objcache should block. 307 */ 308 np = objcache_get(nfsnode_objcache, M_WAITOK); 309 310 error = getnewvnode(VT_NFS, mntp, &vp, 0, 0); 311 if (error) { 312 lockmgr(&nfsnhash_lock, LK_RELEASE); 313 objcache_put(nfsnode_objcache, np); 314 lwkt_reltoken(&nfsnhash_token); 315 return (error); 316 } 317 318 /* 319 * Initialize most of (np). 320 */ 321 bzero(np, sizeof (*np)); 322 if (fhsize > NFS_SMALLFH) { 323 np->n_fhp = kmalloc(fhsize, M_NFSBIGFH, M_WAITOK); 324 } else { 325 np->n_fhp = &np->n_fh; 326 } 327 bcopy((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize); 328 np->n_fhsize = fhsize; 329 lockinit(&np->n_rslock, "nfrslk", 0, lkflags); 330 331 /* 332 * Validate that we did not race another nfs_nget() due to blocking 333 * here and there. 334 */ 335 for (np2 = nhpp->lh_first; np2 != NULL; np2 = np2->n_hash.le_next) { 336 if (mntp != NFSTOV(np2)->v_mount || np2->n_fhsize != fhsize || 337 bcmp((caddr_t)fhp, (caddr_t)np2->n_fhp, fhsize)) { 338 continue; 339 } 340 vx_put(vp); 341 lockmgr(&nfsnhash_lock, LK_RELEASE); 342 343 if (np->n_fhsize > NFS_SMALLFH) 344 kfree((caddr_t)np->n_fhp, M_NFSBIGFH); 345 np->n_fhp = NULL; 346 objcache_put(nfsnode_objcache, np); 347 348 /* 349 * vp state is retained on retry/loop so we must NULL it 350 * out here or fireworks may ensue. 351 */ 352 vp = NULL; 353 goto retry; 354 } 355 356 /* 357 * Finish connecting up (np, vp) and insert the nfsnode in the 358 * hash for its new file handle. 359 * 360 * nvp is locked & refd so effectively so is np. 361 */ 362 np->n_vnode = vp; 363 vp->v_data = np; 364 LIST_INSERT_HEAD(nhpp, np, n_hash); 365 366 /* 367 * nvp is locked & refd so effectively so is np. 368 */ 369 *npp = np; 370 error = 0; 371 lockmgr(&nfsnhash_lock, LK_RELEASE); 372 fail: 373 lwkt_reltoken(&nfsnhash_token); 374 return (error); 375 } 376 377 /* 378 * nfs_inactive(struct vnode *a_vp) 379 * 380 * NOTE: the passed vnode is locked but not referenced. On return the 381 * vnode must be unlocked and not referenced. 382 */ 383 int 384 nfs_inactive(struct vop_inactive_args *ap) 385 { 386 struct nfsmount *nmp = VFSTONFS(ap->a_vp->v_mount); 387 struct nfsnode *np; 388 struct sillyrename *sp; 389 390 lwkt_gettoken(&nmp->nm_token); 391 392 np = VTONFS(ap->a_vp); 393 if (prtactive && VREFCNT(ap->a_vp) > 1) 394 vprint("nfs_inactive: pushing active", ap->a_vp); 395 if (ap->a_vp->v_type != VDIR) { 396 sp = np->n_sillyrename; 397 np->n_sillyrename = NULL; 398 } else { 399 sp = NULL; 400 } 401 if (sp) { 402 /* 403 * We need a reference to keep the vnode from being 404 * recycled by getnewvnode while we do the I/O 405 * associated with discarding the buffers. The vnode 406 * is already locked. 407 */ 408 nfs_vinvalbuf(ap->a_vp, 0, 1); 409 410 /* 411 * Remove the silly file that was rename'd earlier 412 */ 413 nfs_removeit(sp); 414 crfree(sp->s_cred); 415 vrele(sp->s_dvp); 416 kfree((caddr_t)sp, M_NFSREQ); 417 } 418 419 np->n_flag &= ~(NWRITEERR | NACC | NUPD | NCHG | NLOCKED | NWANTED); 420 if (np->n_flag & NREMOVED) 421 vrecycle(ap->a_vp); 422 lwkt_reltoken(&nmp->nm_token); 423 424 return (0); 425 } 426 427 /* 428 * Reclaim an nfsnode so that it can be used for other purposes. 429 * 430 * There should be no direct references to the related nfs node 431 * since nobody is holding the vnode any more, other than hash 432 * lookups which are interlocked against nfsnhash_token and vget(). 433 * 434 * nfs_reclaim(struct vnode *a_vp) 435 */ 436 int 437 nfs_reclaim(struct vop_reclaim_args *ap) 438 { 439 struct vnode *vp = ap->a_vp; 440 struct nfsnode *np = VTONFS(vp); 441 struct nfsdmap *dp, *dp2; 442 /* struct nfsmount *nmp = VFSTONFS(vp->v_mount);*/ 443 444 if (prtactive && VREFCNT(vp) > 1) 445 vprint("nfs_reclaim: pushing active", vp); 446 447 448 /* 449 * Remove from hash table and remove the cross links. 450 * 451 * NOTE: Other NFS code may look up a np and vget() the 452 * related vnode, then will check np->n_vnode. 453 * We must clear np->n_vnode here to ensure that all 454 * possible races are dealt with. 455 */ 456 lwkt_gettoken(&nfsnhash_token); 457 KKASSERT(np->n_vnode == vp); 458 if (np->n_hash.le_prev != NULL) 459 LIST_REMOVE(np, n_hash); 460 np->n_vnode = NULL; 461 vp->v_data = NULL; 462 lwkt_reltoken(&nfsnhash_token); 463 464 /* 465 * Free up any directory cookie structures and 466 * large file handle structures that might be associated with 467 * this nfs node. 468 */ 469 if (vp->v_type == VDIR) { 470 dp = np->n_cookies.lh_first; 471 while (dp) { 472 dp2 = dp; 473 dp = dp->ndm_list.le_next; 474 kfree((caddr_t)dp2, M_NFSDIROFF); 475 } 476 } 477 if (np->n_fhsize > NFS_SMALLFH) { 478 kfree((caddr_t)np->n_fhp, M_NFSBIGFH); 479 } 480 if (np->n_rucred) { 481 crfree(np->n_rucred); 482 np->n_rucred = NULL; 483 } 484 if (np->n_wucred) { 485 crfree(np->n_wucred); 486 np->n_wucred = NULL; 487 } 488 objcache_put(nfsnode_objcache, np); 489 490 return (0); 491 } 492 493