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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)nfs_node.c 8.6 (Berkeley) 5/22/95 37 * $FreeBSD: src/sys/nfs/nfs_node.c,v 1.36.2.3 2002/01/05 22:25:04 dillon Exp $ 38 * $DragonFly: src/sys/vfs/nfs/nfs_node.c,v 1.27 2007/08/08 00:12:51 swildner Exp $ 39 */ 40 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/proc.h> 45 #include <sys/mount.h> 46 #include <sys/namei.h> 47 #include <sys/vnode.h> 48 #include <sys/malloc.h> 49 #include <sys/fnv_hash.h> 50 51 #include <vm/vm_zone.h> 52 53 #include "rpcv2.h" 54 #include "nfsproto.h" 55 #include "nfs.h" 56 #include "nfsmount.h" 57 #include "nfsnode.h" 58 59 static vm_zone_t nfsnode_zone; 60 static LIST_HEAD(nfsnodehashhead, nfsnode) *nfsnodehashtbl; 61 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 nfsnode_zone = zinit("NFSNODE", sizeof(struct nfsnode), 0, 0, 1); 76 nfsnodehashtbl = hashinit(desiredvnodes, M_NFSHASH, &nfsnodehash); 77 } 78 79 /* 80 * Look up a vnode/nfsnode by file handle. 81 * Callers must check for mount points!! 82 * In all cases, a pointer to a 83 * nfsnode structure is returned. 84 */ 85 static int nfs_node_hash_lock; 86 87 int 88 nfs_nget(struct mount *mntp, nfsfh_t *fhp, int fhsize, struct nfsnode **npp) 89 { 90 struct nfsnode *np, *np2; 91 struct nfsnodehashhead *nhpp; 92 struct vnode *vp; 93 struct vnode *nvp; 94 int error; 95 int lkflags; 96 struct nfsmount *nmp; 97 98 /* 99 * Calculate nfs mount point and figure out whether the rslock should 100 * be interruptable or not. 101 */ 102 nmp = VFSTONFS(mntp); 103 if (nmp->nm_flag & NFSMNT_INT) 104 lkflags = LK_PCATCH; 105 else 106 lkflags = 0; 107 108 retry: 109 nhpp = NFSNOHASH(fnv_32_buf(fhp->fh_bytes, fhsize, FNV1_32_INIT)); 110 loop: 111 for (np = nhpp->lh_first; np; np = np->n_hash.le_next) { 112 if (mntp != NFSTOV(np)->v_mount || np->n_fhsize != fhsize || 113 bcmp((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize)) { 114 continue; 115 } 116 vp = NFSTOV(np); 117 if (vget(vp, LK_EXCLUSIVE)) 118 goto loop; 119 for (np = nhpp->lh_first; np; np = np->n_hash.le_next) { 120 if (mntp == NFSTOV(np)->v_mount && 121 np->n_fhsize == fhsize && 122 bcmp((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize) == 0 123 ) { 124 break; 125 } 126 } 127 if (np == NULL || NFSTOV(np) != vp) { 128 vput(vp); 129 goto loop; 130 } 131 *npp = np; 132 return(0); 133 } 134 /* 135 * Obtain a lock to prevent a race condition if the getnewvnode() 136 * or MALLOC() below happens to block. 137 */ 138 if (nfs_node_hash_lock) { 139 while (nfs_node_hash_lock) { 140 nfs_node_hash_lock = -1; 141 tsleep(&nfs_node_hash_lock, 0, "nfsngt", 0); 142 } 143 goto loop; 144 } 145 nfs_node_hash_lock = 1; 146 147 /* 148 * Allocate before getnewvnode since doing so afterward 149 * might cause a bogus v_data pointer to get dereferenced 150 * elsewhere if zalloc should block. 151 */ 152 np = zalloc(nfsnode_zone); 153 154 error = getnewvnode(VT_NFS, mntp, &nvp, 0, 0); 155 if (error) { 156 if (nfs_node_hash_lock < 0) 157 wakeup(&nfs_node_hash_lock); 158 nfs_node_hash_lock = 0; 159 *npp = 0; 160 zfree(nfsnode_zone, np); 161 return (error); 162 } 163 vp = nvp; 164 bzero((caddr_t)np, sizeof *np); 165 np->n_vnode = vp; 166 vp->v_data = np; 167 168 /* 169 * Insert the nfsnode in the hash queue for its new file handle 170 */ 171 for (np2 = nhpp->lh_first; np2 != 0; np2 = np2->n_hash.le_next) { 172 if (mntp != NFSTOV(np2)->v_mount || np2->n_fhsize != fhsize || 173 bcmp((caddr_t)fhp, (caddr_t)np2->n_fhp, fhsize)) 174 continue; 175 vx_put(vp); 176 if (nfs_node_hash_lock < 0) 177 wakeup(&nfs_node_hash_lock); 178 nfs_node_hash_lock = 0; 179 zfree(nfsnode_zone, np); 180 goto retry; 181 } 182 LIST_INSERT_HEAD(nhpp, np, n_hash); 183 if (fhsize > NFS_SMALLFH) { 184 MALLOC(np->n_fhp, nfsfh_t *, fhsize, M_NFSBIGFH, M_WAITOK); 185 } else { 186 np->n_fhp = &np->n_fh; 187 } 188 bcopy((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize); 189 np->n_fhsize = fhsize; 190 lockinit(&np->n_rslock, "nfrslk", 0, lkflags); 191 192 /* 193 * nvp is locked & refd so effectively so is np. 194 */ 195 *npp = np; 196 if (nfs_node_hash_lock < 0) 197 wakeup(&nfs_node_hash_lock); 198 nfs_node_hash_lock = 0; 199 200 return (0); 201 } 202 203 /* 204 * Nonblocking version of nfs_nget() 205 */ 206 int 207 nfs_nget_nonblock(struct mount *mntp, nfsfh_t *fhp, int fhsize, 208 struct nfsnode **npp) 209 { 210 struct nfsnode *np, *np2; 211 struct nfsnodehashhead *nhpp; 212 struct vnode *vp; 213 struct vnode *nvp; 214 int error; 215 int lkflags; 216 struct nfsmount *nmp; 217 218 /* 219 * Calculate nfs mount point and figure out whether the rslock should 220 * be interruptable or not. 221 */ 222 nmp = VFSTONFS(mntp); 223 if (nmp->nm_flag & NFSMNT_INT) 224 lkflags = LK_PCATCH; 225 else 226 lkflags = 0; 227 vp = NULL; 228 *npp = NULL; 229 retry: 230 nhpp = NFSNOHASH(fnv_32_buf(fhp->fh_bytes, fhsize, FNV1_32_INIT)); 231 loop: 232 for (np = nhpp->lh_first; np; np = np->n_hash.le_next) { 233 if (mntp != NFSTOV(np)->v_mount || np->n_fhsize != fhsize || 234 bcmp((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize)) { 235 continue; 236 } 237 if (vp == NULL) { 238 vp = NFSTOV(np); 239 if (vget(vp, LK_EXCLUSIVE | LK_NOWAIT)) { 240 error = EWOULDBLOCK; 241 goto fail; 242 } 243 goto loop; 244 } 245 if (NFSTOV(np) != vp) { 246 vput(vp); 247 vp = NULL; 248 goto loop; 249 } 250 *npp = np; 251 return(0); 252 } 253 254 /* 255 * Not found. If we raced and had acquired a vp we have to release 256 * it here. 257 */ 258 if (vp) { 259 vput(vp); 260 vp = NULL; 261 } 262 263 /* 264 * Obtain a lock to prevent a race condition if the getnewvnode() 265 * or MALLOC() below happens to block. 266 */ 267 if (nfs_node_hash_lock) { 268 while (nfs_node_hash_lock) { 269 nfs_node_hash_lock = -1; 270 tsleep(&nfs_node_hash_lock, 0, "nfsngt", 0); 271 } 272 goto loop; 273 } 274 nfs_node_hash_lock = 1; 275 276 /* 277 * Entry not found, allocate a new entry. 278 * 279 * Allocate before getnewvnode since doing so afterward 280 * might cause a bogus v_data pointer to get dereferenced 281 * elsewhere if zalloc should block. 282 */ 283 np = zalloc(nfsnode_zone); 284 285 error = getnewvnode(VT_NFS, mntp, &nvp, 0, 0); 286 if (error) { 287 if (nfs_node_hash_lock < 0) 288 wakeup(&nfs_node_hash_lock); 289 nfs_node_hash_lock = 0; 290 zfree(nfsnode_zone, np); 291 return (error); 292 } 293 vp = nvp; 294 bzero(np, sizeof (*np)); 295 np->n_vnode = vp; 296 vp->v_data = np; 297 298 /* 299 * Insert the nfsnode in the hash queue for its new file handle. 300 * If someone raced us we free np and vp and try again. 301 */ 302 for (np2 = nhpp->lh_first; np2 != 0; np2 = np2->n_hash.le_next) { 303 if (mntp != NFSTOV(np2)->v_mount || np2->n_fhsize != fhsize || 304 bcmp((caddr_t)fhp, (caddr_t)np2->n_fhp, fhsize)) { 305 continue; 306 } 307 vx_put(vp); 308 if (nfs_node_hash_lock < 0) 309 wakeup(&nfs_node_hash_lock); 310 nfs_node_hash_lock = 0; 311 zfree(nfsnode_zone, np); 312 goto retry; 313 } 314 LIST_INSERT_HEAD(nhpp, np, n_hash); 315 if (fhsize > NFS_SMALLFH) { 316 MALLOC(np->n_fhp, nfsfh_t *, fhsize, M_NFSBIGFH, M_WAITOK); 317 } else { 318 np->n_fhp = &np->n_fh; 319 } 320 bcopy((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize); 321 np->n_fhsize = fhsize; 322 lockinit(&np->n_rslock, "nfrslk", 0, lkflags); 323 324 /* 325 * nvp is locked & refd so effectively so is np. 326 */ 327 *npp = np; 328 error = 0; 329 if (nfs_node_hash_lock < 0) 330 wakeup(&nfs_node_hash_lock); 331 nfs_node_hash_lock = 0; 332 fail: 333 return (error); 334 } 335 336 /* 337 * nfs_inactive(struct vnode *a_vp) 338 * 339 * NOTE: the passed vnode is locked but not referenced. On return the 340 * vnode must be unlocked and not referenced. 341 */ 342 int 343 nfs_inactive(struct vop_inactive_args *ap) 344 { 345 struct nfsmount *nmp = VFSTONFS(ap->a_vp->v_mount); 346 struct nfsnode *np; 347 struct sillyrename *sp; 348 349 lwkt_gettoken(&nmp->nm_token); 350 351 np = VTONFS(ap->a_vp); 352 if (prtactive && ap->a_vp->v_sysref.refcnt > 1) 353 vprint("nfs_inactive: pushing active", ap->a_vp); 354 if (ap->a_vp->v_type != VDIR) { 355 sp = np->n_sillyrename; 356 np->n_sillyrename = NULL; 357 } else { 358 sp = NULL; 359 } 360 if (sp) { 361 /* 362 * We need a reference to keep the vnode from being 363 * recycled by getnewvnode while we do the I/O 364 * associated with discarding the buffers. The vnode 365 * is already locked. 366 */ 367 nfs_vinvalbuf(ap->a_vp, 0, 1); 368 369 /* 370 * Remove the silly file that was rename'd earlier 371 */ 372 nfs_removeit(sp); 373 crfree(sp->s_cred); 374 vrele(sp->s_dvp); 375 FREE((caddr_t)sp, M_NFSREQ); 376 } 377 378 np->n_flag &= ~(NWRITEERR | NACC | NUPD | NCHG | NLOCKED | NWANTED); 379 lwkt_reltoken(&nmp->nm_token); 380 381 return (0); 382 } 383 384 /* 385 * Reclaim an nfsnode so that it can be used for other purposes. 386 * 387 * nfs_reclaim(struct vnode *a_vp) 388 */ 389 int 390 nfs_reclaim(struct vop_reclaim_args *ap) 391 { 392 struct vnode *vp = ap->a_vp; 393 struct nfsnode *np = VTONFS(vp); 394 struct nfsdmap *dp, *dp2; 395 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 396 397 if (prtactive && vp->v_sysref.refcnt > 1) 398 vprint("nfs_reclaim: pushing active", vp); 399 400 lwkt_gettoken(&nmp->nm_token); 401 402 if (np->n_hash.le_prev != NULL) 403 LIST_REMOVE(np, n_hash); 404 405 /* 406 * Free up any directory cookie structures and 407 * large file handle structures that might be associated with 408 * this nfs node. 409 */ 410 if (vp->v_type == VDIR) { 411 dp = np->n_cookies.lh_first; 412 while (dp) { 413 dp2 = dp; 414 dp = dp->ndm_list.le_next; 415 FREE((caddr_t)dp2, M_NFSDIROFF); 416 } 417 } 418 if (np->n_fhsize > NFS_SMALLFH) { 419 FREE((caddr_t)np->n_fhp, M_NFSBIGFH); 420 } 421 if (np->n_rucred) { 422 crfree(np->n_rucred); 423 np->n_rucred = NULL; 424 } 425 if (np->n_wucred) { 426 crfree(np->n_wucred); 427 np->n_wucred = NULL; 428 } 429 vp->v_data = NULL; 430 431 lwkt_reltoken(&nmp->nm_token); 432 zfree(nfsnode_zone, np); 433 434 return (0); 435 } 436 437