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. 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 /*
  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, 0);
 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, 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)
 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_sysref.refcnt > 1)
 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                  * Remove the silly file that was rename'd earlier
 233                  */
 234                 nfs_removeit(sp);
 235                 crfree(sp->s_cred);
 236                 vrele(sp->s_dvp);
 237                 FREE((caddr_t)sp, M_NFSREQ);
 238         }
 239
 240         np->n_flag &= ~(NWRITEERR | NACC | NUPD | NCHG | NLOCKED | NWANTED);
 241
 242         return (0);
 243 }
 244
 245 /*
 246  * Reclaim an nfsnode so that it can be used for other purposes.
 247  *
 248  * nfs_reclaim(struct vnode *a_vp)
 249  */
 250 int
 251 nfs_reclaim(struct vop_reclaim_args *ap)
 252 {
 253         struct vnode *vp = ap->a_vp;
 254         struct nfsnode *np = VTONFS(vp);
 255         struct nfsdmap *dp, *dp2;
 256
 257         if (prtactive && vp->v_sysref.refcnt > 1)
 258                 vprint("nfs_reclaim: pushing active", vp);
 259
 260         if (np->n_hash.le_prev != NULL)
 261                 LIST_REMOVE(np, n_hash);
 262
 263         /*
 264          * Free up any directory cookie structures and
 265          * large file handle structures that might be associated with
 266          * this nfs node.
 267          */
 268         if (vp->v_type == VDIR) {
 269                 dp = np->n_cookies.lh_first;
 270                 while (dp) {
 271                         dp2 = dp;
 272                         dp = dp->ndm_list.le_next;
 273                         FREE((caddr_t)dp2, M_NFSDIROFF);
 274                 }
 275         }
 276         if (np->n_fhsize > NFS_SMALLFH) {
 277                 FREE((caddr_t)np->n_fhp, M_NFSBIGFH);
 278         }
 279         if (np->n_rucred) {
 280                 crfree(np->n_rucred);
 281                 np->n_rucred = NULL;
 282         }
 283         if (np->n_wucred) {
 284                 crfree(np->n_wucred);
 285                 np->n_wucred = NULL;
 286         }
 287
 288         vp->v_data = NULL;
 289         zfree(nfsnode_zone, np);
 290         return (0);
 291 }
 292