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 1.23 2006/05/06 02:43:14 dillon 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 /* 67 * Initialize hash links for nfsnodes 68 * and build nfsnode free list. 69 */ 70 void 71 nfs_nhinit(void) 72 { 73 nfsnode_zone = zinit("NFSNODE", sizeof(struct nfsnode), 0, 0, 1); 74 nfsnodehashtbl = hashinit(desiredvnodes, M_NFSHASH, &nfsnodehash); 75 } 76 77 /* 78 * Look up a vnode/nfsnode by file handle. 79 * Callers must check for mount points!! 80 * In all cases, a pointer to a 81 * nfsnode structure is returned. 82 */ 83 static int nfs_node_hash_lock; 84 85 int 86 nfs_nget(struct mount *mntp, nfsfh_t *fhp, int fhsize, struct nfsnode **npp) 87 { 88 struct nfsnode *np, *np2; 89 struct nfsnodehashhead *nhpp; 90 struct vnode *vp; 91 struct vnode *nvp; 92 int error; 93 int lkflags; 94 struct nfsmount *nmp; 95 96 /* 97 * Calculate nfs mount point and figure out whether the rslock should 98 * be interruptable or not. 99 */ 100 nmp = VFSTONFS(mntp); 101 if (nmp->nm_flag & NFSMNT_INT) 102 lkflags = LK_PCATCH; 103 else 104 lkflags = 0; 105 106 retry: 107 nhpp = NFSNOHASH(fnv_32_buf(fhp->fh_bytes, fhsize, FNV1_32_INIT)); 108 loop: 109 for (np = nhpp->lh_first; np; np = np->n_hash.le_next) { 110 if (mntp != NFSTOV(np)->v_mount || np->n_fhsize != fhsize || 111 bcmp((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize)) { 112 continue; 113 } 114 vp = NFSTOV(np); 115 if (vget(vp, LK_EXCLUSIVE)) 116 goto loop; 117 for (np = nhpp->lh_first; np; np = np->n_hash.le_next) { 118 if (mntp == NFSTOV(np)->v_mount && 119 np->n_fhsize == fhsize && 120 bcmp((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize) == 0 121 ) { 122 break; 123 } 124 } 125 if (np == NULL || NFSTOV(np) != vp) { 126 vput(vp); 127 goto loop; 128 } 129 *npp = np; 130 return(0); 131 } 132 /* 133 * Obtain a lock to prevent a race condition if the getnewvnode() 134 * or MALLOC() below happens to block. 135 */ 136 if (nfs_node_hash_lock) { 137 while (nfs_node_hash_lock) { 138 nfs_node_hash_lock = -1; 139 tsleep(&nfs_node_hash_lock, 0, "nfsngt", 0); 140 } 141 goto loop; 142 } 143 nfs_node_hash_lock = 1; 144 145 /* 146 * Allocate before getnewvnode since doing so afterward 147 * might cause a bogus v_data pointer to get dereferenced 148 * elsewhere if zalloc should block. 149 */ 150 np = zalloc(nfsnode_zone); 151 152 error = getnewvnode(VT_NFS, mntp, &nvp, 0, LK_NOPAUSE); 153 if (error) { 154 if (nfs_node_hash_lock < 0) 155 wakeup(&nfs_node_hash_lock); 156 nfs_node_hash_lock = 0; 157 *npp = 0; 158 zfree(nfsnode_zone, np); 159 return (error); 160 } 161 vp = nvp; 162 bzero((caddr_t)np, sizeof *np); 163 np->n_vnode = vp; 164 vp->v_data = np; 165 166 /* 167 * Insert the nfsnode in the hash queue for its new file handle 168 */ 169 for (np2 = nhpp->lh_first; np2 != 0; np2 = np2->n_hash.le_next) { 170 if (mntp != NFSTOV(np2)->v_mount || np2->n_fhsize != fhsize || 171 bcmp((caddr_t)fhp, (caddr_t)np2->n_fhp, fhsize)) 172 continue; 173 vx_put(vp); 174 if (nfs_node_hash_lock < 0) 175 wakeup(&nfs_node_hash_lock); 176 nfs_node_hash_lock = 0; 177 zfree(nfsnode_zone, np); 178 goto retry; 179 } 180 LIST_INSERT_HEAD(nhpp, np, n_hash); 181 if (fhsize > NFS_SMALLFH) { 182 MALLOC(np->n_fhp, nfsfh_t *, fhsize, M_NFSBIGFH, M_WAITOK); 183 } else 184 np->n_fhp = &np->n_fh; 185 bcopy((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize); 186 np->n_fhsize = fhsize; 187 lockinit(&np->n_rslock, "nfrslk", 0, LK_NOPAUSE | lkflags); 188 189 /* 190 * nvp is locked & refd so effectively so is np. 191 */ 192 *npp = np; 193 194 if (nfs_node_hash_lock < 0) 195 wakeup(&nfs_node_hash_lock); 196 nfs_node_hash_lock = 0; 197 198 return (0); 199 } 200 201 /* 202 * nfs_inactive(struct vnode *a_vp, struct thread *a_td) 203 * 204 * NOTE: the passed vnode is locked but not referenced. On return the 205 * vnode must be unlocked and not referenced. 206 */ 207 int 208 nfs_inactive(struct vop_inactive_args *ap) 209 { 210 struct nfsnode *np; 211 struct sillyrename *sp; 212 213 np = VTONFS(ap->a_vp); 214 if (prtactive && ap->a_vp->v_usecount != 0) 215 vprint("nfs_inactive: pushing active", ap->a_vp); 216 if (ap->a_vp->v_type != VDIR) { 217 sp = np->n_sillyrename; 218 np->n_sillyrename = NULL; 219 } else { 220 sp = NULL; 221 } 222 if (sp) { 223 /* 224 * We need a reference to keep the vnode from being 225 * recycled by getnewvnode while we do the I/O 226 * associated with discarding the buffers. The vnode 227 * is already locked. 228 */ 229 nfs_vinvalbuf(ap->a_vp, 0, 1); 230 231 /* 232 * Either we have the only ref or we were vgone()'d via 233 * revoke and might have more. 234 */ 235 KKASSERT(ap->a_vp->v_usecount == 1 || 236 (ap->a_vp->v_flag & VRECLAIMED)); 237 238 /* 239 * Remove the silly file that was rename'd earlier 240 */ 241 nfs_removeit(sp); 242 crfree(sp->s_cred); 243 vrele(sp->s_dvp); 244 FREE((caddr_t)sp, M_NFSREQ); 245 } 246 247 np->n_flag &= ~(NWRITEERR | NACC | NUPD | NCHG | NLOCKED | NWANTED); 248 249 return (0); 250 } 251 252 /* 253 * Reclaim an nfsnode so that it can be used for other purposes. 254 * 255 * nfs_reclaim(struct vnode *a_vp) 256 */ 257 int 258 nfs_reclaim(struct vop_reclaim_args *ap) 259 { 260 struct vnode *vp = ap->a_vp; 261 struct nfsnode *np = VTONFS(vp); 262 struct nfsdmap *dp, *dp2; 263 264 if (prtactive && vp->v_usecount != 0) 265 vprint("nfs_reclaim: pushing active", vp); 266 267 if (np->n_hash.le_prev != NULL) 268 LIST_REMOVE(np, n_hash); 269 270 /* 271 * Free up any directory cookie structures and 272 * large file handle structures that might be associated with 273 * this nfs node. 274 */ 275 if (vp->v_type == VDIR) { 276 dp = np->n_cookies.lh_first; 277 while (dp) { 278 dp2 = dp; 279 dp = dp->ndm_list.le_next; 280 FREE((caddr_t)dp2, M_NFSDIROFF); 281 } 282 } 283 if (np->n_fhsize > NFS_SMALLFH) { 284 FREE((caddr_t)np->n_fhp, M_NFSBIGFH); 285 } 286 if (np->n_rucred) { 287 crfree(np->n_rucred); 288 np->n_rucred = NULL; 289 } 290 if (np->n_wucred) { 291 crfree(np->n_wucred); 292 np->n_wucred = NULL; 293 } 294 295 vp->v_data = NULL; 296 zfree(nfsnode_zone, np); 297 return (0); 298 } 299 300 #if 0 301 /* 302 * Lock an nfsnode 303 * 304 * nfs_lock(struct vnode *a_vp) 305 */ 306 int 307 nfs_lock(struct vop_lock_args *ap) 308 { 309 struct vnode *vp = ap->a_vp; 310 311 /* 312 * Ugh, another place where interruptible mounts will get hung. 313 * If you make this sleep interruptible, then you have to fix all 314 * the VOP_LOCK() calls to expect interruptibility. 315 */ 316 while (vp->v_flag & VXLOCK) { 317 vp->v_flag |= VXWANT; 318 (void) tsleep((caddr_t)vp, 0, "nfslck", 0); 319 } 320 if (vp->v_tag == VT_NON) 321 return (ENOENT); 322 323 #if 0 324 /* 325 * Only lock regular files. If a server crashed while we were 326 * holding a directory lock, we could easily end up sleeping 327 * until the server rebooted while holding a lock on the root. 328 * Locks are only needed for protecting critical sections in 329 * VMIO at the moment. 330 * New vnodes will have type VNON but they should be locked 331 * since they may become VREG. This is checked in loadattrcache 332 * and unwanted locks are released there. 333 */ 334 if (vp->v_type == VREG || vp->v_type == VNON) { 335 while (np->n_flag & NLOCKED) { 336 np->n_flag |= NWANTED; 337 (void) tsleep((caddr_t) np, 0, "nfslck2", 0); 338 /* 339 * If the vnode has transmuted into a VDIR while we 340 * were asleep, then skip the lock. 341 */ 342 if (vp->v_type != VREG && vp->v_type != VNON) 343 return (0); 344 } 345 np->n_flag |= NLOCKED; 346 } 347 #endif 348 349 return (0); 350 } 351 352 /* 353 * Unlock an nfsnode 354 * 355 * nfs_unlock(struct vnode *a_vp) 356 */ 357 int 358 nfs_unlock(struct vop_unlock_args *ap) 359 { 360 #if 0 361 struct vnode* vp = ap->a_vp; 362 struct nfsnode* np = VTONFS(vp); 363 364 if (vp->v_type == VREG || vp->v_type == VNON) { 365 if (!(np->n_flag & NLOCKED)) 366 panic("nfs_unlock: nfsnode not locked"); 367 np->n_flag &= ~NLOCKED; 368 if (np->n_flag & NWANTED) { 369 np->n_flag &= ~NWANTED; 370 wakeup((caddr_t) np); 371 } 372 } 373 #endif 374 375 return (0); 376 } 377 378 /* 379 * Check for a locked nfsnode 380 * 381 * nfs_islocked(struct vnode *a_vp, struct thread *a_td) 382 */ 383 int 384 nfs_islocked(struct vop_islocked_args *ap) 385 { 386 return VTONFS(ap->a_vp)->n_flag & NLOCKED ? 1 : 0; 387 } 388 #endif 389 390