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/vnode.h> 42 #include <sys/malloc.h> 43 #include <sys/kernel.h> 44 #include <sys/fnv_hash.h> 45 #include <sys/objcache.h> 46 47 #include "rpcv2.h" 48 #include "nfsproto.h" 49 #include "nfs.h" 50 #include "nfsmount.h" 51 #include "nfsnode.h" 52 53 static MALLOC_DEFINE(M_NFSNODE, "NFS node", "NFS node"); 54 55 static struct lwkt_token nfsnhash_token = 56 LWKT_TOKEN_INITIALIZER(nfsnhash_token); 57 static struct lock nfsnhash_lock; 58 __read_mostly static struct objcache *nfsnode_objcache; 59 __read_mostly static LIST_HEAD(nfsnodehashhead, nfsnode) *nfsnodehashtbl; 60 __read_mostly static u_long nfsnodehash; 61 62 #define TRUE 1 63 #define FALSE 0 64 65 #define NFSNOHASH(fhsum) (&nfsnodehashtbl[(fhsum) & nfsnodehash]) 66 67 /* 68 * Initialize hash links for nfsnodes 69 * and build nfsnode free list. 70 */ 71 void 72 nfs_nhinit(void) 73 { 74 int hsize = vfs_inodehashsize(); 75 76 nfsnode_objcache = objcache_create_simple(M_NFSNODE, 77 sizeof(struct nfsnode)); 78 nfsnodehashtbl = hashinit(hsize, M_NFSHASH, &nfsnodehash); 79 lockinit(&nfsnhash_lock, "nfsnht", 0, 0); 80 } 81 82 void 83 nfs_nhdestroy(void) 84 { 85 hashdestroy(nfsnodehashtbl, M_NFSHASH, nfsnodehash); 86 objcache_destroy(nfsnode_objcache); 87 } 88 89 /* 90 * Look up a vnode/nfsnode by file handle. 91 * Callers must check for mount points!! 92 * In all cases, a pointer to a 93 * nfsnode structure is returned. 94 */ 95 96 int 97 nfs_nget(struct mount *mntp, nfsfh_t *fhp, int fhsize, struct nfsnode **npp, 98 struct vnode *notvp) 99 { 100 struct nfsnode *np, *np2; 101 struct nfsnodehashhead *nhpp; 102 struct vnode *vp; 103 int error; 104 int lkflags; 105 struct nfsmount *nmp; 106 107 /* 108 * Calculate nfs mount point and figure out whether the rslock should 109 * be interruptable or not. 110 */ 111 nmp = VFSTONFS(mntp); 112 if (nmp->nm_flag & NFSMNT_INT) 113 lkflags = LK_PCATCH; 114 else 115 lkflags = 0; 116 117 lwkt_gettoken(&nfsnhash_token); 118 119 retry: 120 nhpp = NFSNOHASH(fnv_32_buf(fhp->fh_bytes, fhsize, FNV1_32_INIT)); 121 loop: 122 LIST_FOREACH(np, nhpp, n_hash) { 123 if (mntp != NFSTOV(np)->v_mount || np->n_fhsize != fhsize || 124 bcmp((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize)) { 125 continue; 126 } 127 vp = NFSTOV(np); 128 if (vp == notvp) { 129 kprintf("nfs warning: client-client collision " 130 "during rename/link/softlink\n"); 131 *npp = NULL; 132 lwkt_reltoken(&nfsnhash_token); 133 return (ESTALE); 134 } 135 if (vget(vp, LK_EXCLUSIVE)) 136 goto loop; 137 LIST_FOREACH(np, nhpp, n_hash) { 138 if (mntp == NFSTOV(np)->v_mount && 139 np->n_fhsize == fhsize && 140 bcmp((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize) == 0 141 ) { 142 break; 143 } 144 } 145 if (np == NULL || NFSTOV(np) != vp) { 146 vput(vp); 147 goto loop; 148 } 149 *npp = np; 150 lwkt_reltoken(&nfsnhash_token); 151 return(0); 152 } 153 154 /* 155 * Obtain a lock to prevent a race condition if the getnewvnode() 156 * or MALLOC() below happens to block. 157 */ 158 if (lockmgr(&nfsnhash_lock, LK_EXCLUSIVE | LK_SLEEPFAIL)) 159 goto loop; 160 161 /* 162 * Allocate before getnewvnode since doing so afterward 163 * might cause a bogus v_data pointer to get dereferenced 164 * elsewhere if objcache should block. 165 */ 166 np = objcache_get(nfsnode_objcache, M_WAITOK); 167 168 error = getnewvnode(VT_NFS, mntp, &vp, 0, 0); 169 if (error) { 170 lockmgr(&nfsnhash_lock, LK_RELEASE); 171 *npp = NULL; 172 objcache_put(nfsnode_objcache, np); 173 lwkt_reltoken(&nfsnhash_token); 174 return (error); 175 } 176 177 /* 178 * Initialize most of (np). 179 */ 180 bzero(np, sizeof (*np)); 181 if (fhsize > NFS_SMALLFH) { 182 np->n_fhp = kmalloc(fhsize, M_NFSBIGFH, M_WAITOK); 183 } else { 184 np->n_fhp = &np->n_fh; 185 } 186 bcopy((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize); 187 np->n_fhsize = fhsize; 188 lockinit(&np->n_rslock, "nfrslk", 0, lkflags); 189 190 /* 191 * Validate that we did not race another nfs_nget() due to blocking 192 * here and there. 193 */ 194 for (np2 = nhpp->lh_first; np2 != NULL; np2 = np2->n_hash.le_next) { 195 if (mntp != NFSTOV(np2)->v_mount || np2->n_fhsize != fhsize || 196 bcmp((caddr_t)fhp, (caddr_t)np2->n_fhp, fhsize)) { 197 continue; 198 } 199 vx_put(vp); 200 lockmgr(&nfsnhash_lock, LK_RELEASE); 201 202 if (np->n_fhsize > NFS_SMALLFH) 203 kfree((caddr_t)np->n_fhp, M_NFSBIGFH); 204 np->n_fhp = NULL; 205 objcache_put(nfsnode_objcache, np); 206 goto retry; 207 } 208 209 /* 210 * Finish connecting up (np, vp) and insert the nfsnode in the 211 * hash for its new file handle. 212 * 213 * nvp is locked & refd so effectively so is np. 214 */ 215 np->n_vnode = vp; 216 vp->v_data = np; 217 LIST_INSERT_HEAD(nhpp, np, n_hash); 218 *npp = np; 219 lockmgr(&nfsnhash_lock, LK_RELEASE); 220 lwkt_reltoken(&nfsnhash_token); 221 vx_downgrade(vp); 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 vx_downgrade(vp); 373 fail: 374 lwkt_reltoken(&nfsnhash_token); 375 return (error); 376 } 377 378 /* 379 * nfs_inactive(struct vnode *a_vp) 380 * 381 * NOTE: the passed vnode is locked but not referenced. On return the 382 * vnode must be unlocked and not referenced. 383 */ 384 int 385 nfs_inactive(struct vop_inactive_args *ap) 386 { 387 struct nfsmount *nmp = VFSTONFS(ap->a_vp->v_mount); 388 struct nfsnode *np; 389 struct sillyrename *sp; 390 391 lwkt_gettoken(&nmp->nm_token); 392 393 np = VTONFS(ap->a_vp); 394 if (prtactive && VREFCNT(ap->a_vp) > 1) 395 vprint("nfs_inactive: pushing active", ap->a_vp); 396 if (ap->a_vp->v_type != VDIR) { 397 sp = np->n_sillyrename; 398 np->n_sillyrename = NULL; 399 } else { 400 sp = NULL; 401 } 402 if (sp) { 403 /* 404 * We need a reference to keep the vnode from being 405 * recycled by getnewvnode while we do the I/O 406 * associated with discarding the buffers. The vnode 407 * is already locked. 408 */ 409 nfs_vinvalbuf(ap->a_vp, 0, 1); 410 411 /* 412 * Remove the silly file that was rename'd earlier 413 */ 414 nfs_removeit(sp); 415 crfree(sp->s_cred); 416 vrele(sp->s_dvp); 417 kfree((caddr_t)sp, M_NFSREQ); 418 } 419 420 np->n_flag &= ~(NWRITEERR | NACC | NUPD | NCHG | NLOCKED | NWANTED); 421 if (np->n_flag & NREMOVED) 422 vrecycle(ap->a_vp); 423 lwkt_reltoken(&nmp->nm_token); 424 425 return (0); 426 } 427 428 /* 429 * Reclaim an nfsnode so that it can be used for other purposes. 430 * 431 * There should be no direct references to the related nfs node 432 * since nobody is holding the vnode any more, other than hash 433 * lookups which are interlocked against nfsnhash_token and vget(). 434 * 435 * nfs_reclaim(struct vnode *a_vp) 436 */ 437 int 438 nfs_reclaim(struct vop_reclaim_args *ap) 439 { 440 struct vnode *vp = ap->a_vp; 441 struct nfsnode *np = VTONFS(vp); 442 struct nfsdmap *dp, *dp2; 443 /* struct nfsmount *nmp = VFSTONFS(vp->v_mount);*/ 444 445 if (prtactive && VREFCNT(vp) > 1) 446 vprint("nfs_reclaim: pushing active", vp); 447 448 449 /* 450 * Remove from hash table and remove the cross links. 451 * 452 * NOTE: Other NFS code may look up a np and vget() the 453 * related vnode, then will check np->n_vnode. 454 * We must clear np->n_vnode here to ensure that all 455 * possible races are dealt with. 456 */ 457 lwkt_gettoken(&nfsnhash_token); 458 KKASSERT(np->n_vnode == vp); 459 if (np->n_hash.le_prev != NULL) 460 LIST_REMOVE(np, n_hash); 461 np->n_vnode = NULL; 462 vp->v_data = NULL; 463 lwkt_reltoken(&nfsnhash_token); 464 465 /* 466 * Free up any directory cookie structures and 467 * large file handle structures that might be associated with 468 * this nfs node. 469 */ 470 if (vp->v_type == VDIR) { 471 dp = np->n_cookies.lh_first; 472 while (dp) { 473 dp2 = dp; 474 dp = dp->ndm_list.le_next; 475 kfree((caddr_t)dp2, M_NFSDIROFF); 476 } 477 } 478 if (np->n_fhsize > NFS_SMALLFH) { 479 kfree((caddr_t)np->n_fhp, M_NFSBIGFH); 480 } 481 if (np->n_rucred) { 482 crfree(np->n_rucred); 483 np->n_rucred = NULL; 484 } 485 if (np->n_wucred) { 486 crfree(np->n_wucred); 487 np->n_wucred = NULL; 488 } 489 objcache_put(nfsnode_objcache, np); 490 491 return (0); 492 } 493 494