sys/vfs/nfs/nfs_node.c

   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