FreeBSD/Linux Kernel Cross Reference
sys/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 * $FreeBSD$
38 */
39
40
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/proc.h>
44 #include <sys/mount.h>
45 #include <sys/namei.h>
46 #include <sys/vnode.h>
47 #include <sys/malloc.h>
48 #include <sys/fnv_hash.h>
49
50 #include <vm/vm_zone.h>
51
52 #include <nfs/rpcv2.h>
53 #include <nfs/nfsproto.h>
54 #include <nfs/nfs.h>
55 #include <nfs/nfsnode.h>
56 #include <nfs/nfsmount.h>
57
58 static vm_zone_t nfsnode_zone;
59 static LIST_HEAD(nfsnodehashhead, nfsnode) *nfsnodehashtbl;
60 static u_long nfsnodehash;
61
62 #define TRUE 1
63 #define FALSE 0
64
65 /*
66 * Initialize hash links for nfsnodes
67 * and build nfsnode free list.
68 */
69 void
70 nfs_nhinit()
71 {
72 nfsnode_zone = zinit("NFSNODE", sizeof(struct nfsnode), 0, 0, 1);
73 nfsnodehashtbl = hashinit(desiredvnodes, M_NFSHASH, &nfsnodehash);
74 }
75
76 /*
77 * Look up a vnode/nfsnode by file handle.
78 * Callers must check for mount points!!
79 * In all cases, a pointer to a
80 * nfsnode structure is returned.
81 */
82 static int nfs_node_hash_lock;
83
84 int
85 nfs_nget(mntp, fhp, fhsize, npp)
86 struct mount *mntp;
87 register nfsfh_t *fhp;
88 int fhsize;
89 struct nfsnode **npp;
90 {
91 struct proc *p = curproc; /* XXX */
92 struct nfsnode *np, *np2;
93 struct nfsnodehashhead *nhpp;
94 register struct vnode *vp;
95 struct vnode *nvp;
96 int error;
97 int rsflags;
98 struct nfsmount *nmp;
99
100 /*
101 * Calculate nfs mount point and figure out whether the rslock should
102 * be interruptable or not.
103 */
104 nmp = VFSTONFS(mntp);
105 if (nmp->nm_flag & NFSMNT_INT)
106 rsflags = PCATCH;
107 else
108 rsflags = 0;
109
110 retry:
111 nhpp = NFSNOHASH(fnv_32_buf(fhp->fh_bytes, fhsize, FNV1_32_INIT));
112 loop:
113 for (np = nhpp->lh_first; np != 0; np = np->n_hash.le_next) {
114 if (mntp != NFSTOV(np)->v_mount || np->n_fhsize != fhsize ||
115 bcmp((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize))
116 continue;
117 vp = NFSTOV(np);
118 if (vget(vp, LK_EXCLUSIVE|LK_SLEEPFAIL, p))
119 goto loop;
120 *npp = np;
121 return(0);
122 }
123 /*
124 * Obtain a lock to prevent a race condition if the getnewvnode()
125 * or MALLOC() below happens to block.
126 */
127 if (nfs_node_hash_lock) {
128 while (nfs_node_hash_lock) {
129 nfs_node_hash_lock = -1;
130 tsleep(&nfs_node_hash_lock, PVM, "nfsngt", 0);
131 }
132 goto loop;
133 }
134 nfs_node_hash_lock = 1;
135
136 /*
137 * Allocate before getnewvnode since doing so afterward
138 * might cause a bogus v_data pointer to get dereferenced
139 * elsewhere if zalloc should block.
140 */
141 np = zalloc(nfsnode_zone);
142
143 error = getnewvnode(VT_NFS, mntp, nfsv2_vnodeop_p, &nvp);
144 if (error) {
145 if (nfs_node_hash_lock < 0)
146 wakeup(&nfs_node_hash_lock);
147 nfs_node_hash_lock = 0;
148 *npp = 0;
149 zfree(nfsnode_zone, np);
150 return (error);
151 }
152 vp = nvp;
153 bzero((caddr_t)np, sizeof *np);
154 vp->v_data = np;
155 np->n_vnode = vp;
156 /*
157 * Insert the nfsnode in the hash queue for its new file handle
158 */
159 for (np2 = nhpp->lh_first; np2 != 0; np2 = np2->n_hash.le_next) {
160 if (mntp != NFSTOV(np2)->v_mount || np2->n_fhsize != fhsize ||
161 bcmp((caddr_t)fhp, (caddr_t)np2->n_fhp, fhsize))
162 continue;
163 vrele(vp);
164 if (nfs_node_hash_lock < 0)
165 wakeup(&nfs_node_hash_lock);
166 nfs_node_hash_lock = 0;
167 zfree(nfsnode_zone, np);
168 goto retry;
169 }
170 LIST_INSERT_HEAD(nhpp, np, n_hash);
171 if (fhsize > NFS_SMALLFH) {
172 MALLOC(np->n_fhp, nfsfh_t *, fhsize, M_NFSBIGFH, M_WAITOK);
173 } else
174 np->n_fhp = &np->n_fh;
175 bcopy((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize);
176 np->n_fhsize = fhsize;
177 lockinit(&np->n_rslock, PVFS | rsflags, "nfrslk", 0, LK_NOPAUSE);
178 lockinit(&np->n_lock, PVFS, "nfsnlk", 0, LK_NOPAUSE);
179 *npp = np;
180
181 if (nfs_node_hash_lock < 0)
182 wakeup(&nfs_node_hash_lock);
183 nfs_node_hash_lock = 0;
184
185 /*
186 * Lock the new nfsnode.
187 */
188 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
189
190 return (0);
191 }
192
193 int
194 nfs_inactive(ap)
195 struct vop_inactive_args /* {
196 struct vnode *a_vp;
197 struct proc *a_p;
198 } */ *ap;
199 {
200 register struct nfsnode *np;
201 register struct sillyrename *sp;
202 struct proc *p = curproc; /* XXX */
203
204 np = VTONFS(ap->a_vp);
205 if (prtactive && ap->a_vp->v_usecount != 0)
206 vprint("nfs_inactive: pushing active", ap->a_vp);
207 if (ap->a_vp->v_type != VDIR) {
208 sp = np->n_sillyrename;
209 np->n_sillyrename = (struct sillyrename *)0;
210 } else
211 sp = (struct sillyrename *)0;
212 if (sp) {
213 /*
214 * We need a reference to keep the vnode from being
215 * recycled by getnewvnode while we do the I/O
216 * associated with discarding the buffers unless we
217 * are being forcibly unmounted in which case we already
218 * have our own reference.
219 */
220 if (ap->a_vp->v_usecount > 0)
221 (void) nfs_vinvalbuf(ap->a_vp, 0, sp->s_cred, p, 1);
222 else if (vget(ap->a_vp, 0, p))
223 panic("nfs_inactive: lost vnode");
224 else {
225 (void) nfs_vinvalbuf(ap->a_vp, 0, sp->s_cred, p, 1);
226 vrele(ap->a_vp);
227 }
228 /*
229 * Remove the silly file that was rename'd earlier
230 */
231 nfs_removeit(sp);
232 crfree(sp->s_cred);
233 vrele(sp->s_dvp);
234 FREE((caddr_t)sp, M_NFSREQ);
235 }
236 np->n_flag &= (NMODIFIED | NFLUSHINPROG | NFLUSHWANT | NQNFSEVICTED |
237 NQNFSNONCACHE | NQNFSWRITE);
238 VOP_UNLOCK(ap->a_vp, 0, ap->a_p);
239 return (0);
240 }
241
242 /*
243 * Reclaim an nfsnode so that it can be used for other purposes.
244 */
245 int
246 nfs_reclaim(ap)
247 struct vop_reclaim_args /* {
248 struct vnode *a_vp;
249 } */ *ap;
250 {
251 register struct vnode *vp = ap->a_vp;
252 register struct nfsnode *np = VTONFS(vp);
253 register struct nfsmount *nmp = VFSTONFS(vp->v_mount);
254 register struct nfsdmap *dp, *dp2;
255
256 if (prtactive && vp->v_usecount != 0)
257 vprint("nfs_reclaim: pushing active", vp);
258
259 if (np->n_hash.le_prev != NULL)
260 LIST_REMOVE(np, n_hash);
261
262 /*
263 * For nqnfs, take it off the timer queue as required.
264 */
265 if ((nmp->nm_flag & NFSMNT_NQNFS) && np->n_timer.cqe_next != 0) {
266 CIRCLEQ_REMOVE(&nmp->nm_timerhead, np, n_timer);
267 }
268
269 /*
270 * Free up any directory cookie structures and
271 * large file handle structures that might be associated with
272 * this nfs node.
273 */
274 if (vp->v_type == VDIR) {
275 dp = np->n_cookies.lh_first;
276 while (dp) {
277 dp2 = dp;
278 dp = dp->ndm_list.le_next;
279 FREE((caddr_t)dp2, M_NFSDIROFF);
280 }
281 }
282 if (np->n_fhsize > NFS_SMALLFH) {
283 FREE((caddr_t)np->n_fhp, M_NFSBIGFH);
284 }
285
286 cache_purge(vp);
287 zfree(nfsnode_zone, vp->v_data);
288 vp->v_data = (void *)0;
289 return (0);
290 }
291
292 #if 0
293 /*
294 * Lock an nfsnode
295 */
296 int
297 nfs_lock(ap)
298 struct vop_lock_args /* {
299 struct vnode *a_vp;
300 } */ *ap;
301 {
302 register struct vnode *vp = ap->a_vp;
303
304 /*
305 * Ugh, another place where interruptible mounts will get hung.
306 * If you make this sleep interruptible, then you have to fix all
307 * the VOP_LOCK() calls to expect interruptibility.
308 */
309 while (vp->v_flag & VXLOCK) {
310 vp->v_flag |= VXWANT;
311 (void) tsleep((caddr_t)vp, PINOD, "nfslck", 0);
312 }
313 if (vp->v_tag == VT_NON)
314 return (ENOENT);
315
316 #if 0
317 /*
318 * Only lock regular files. If a server crashed while we were
319 * holding a directory lock, we could easily end up sleeping
320 * until the server rebooted while holding a lock on the root.
321 * Locks are only needed for protecting critical sections in
322 * VMIO at the moment.
323 * New vnodes will have type VNON but they should be locked
324 * since they may become VREG. This is checked in loadattrcache
325 * and unwanted locks are released there.
326 */
327 if (vp->v_type == VREG || vp->v_type == VNON) {
328 while (np->n_flag & NLOCKED) {
329 np->n_flag |= NWANTED;
330 (void) tsleep((caddr_t) np, PINOD, "nfslck2", 0);
331 /*
332 * If the vnode has transmuted into a VDIR while we
333 * were asleep, then skip the lock.
334 */
335 if (vp->v_type != VREG && vp->v_type != VNON)
336 return (0);
337 }
338 np->n_flag |= NLOCKED;
339 }
340 #endif
341
342 return (0);
343 }
344
345 /*
346 * Unlock an nfsnode
347 */
348 int
349 nfs_unlock(ap)
350 struct vop_unlock_args /* {
351 struct vnode *a_vp;
352 } */ *ap;
353 {
354 #if 0
355 struct vnode* vp = ap->a_vp;
356 struct nfsnode* np = VTONFS(vp);
357
358 if (vp->v_type == VREG || vp->v_type == VNON) {
359 if (!(np->n_flag & NLOCKED))
360 panic("nfs_unlock: nfsnode not locked");
361 np->n_flag &= ~NLOCKED;
362 if (np->n_flag & NWANTED) {
363 np->n_flag &= ~NWANTED;
364 wakeup((caddr_t) np);
365 }
366 }
367 #endif
368
369 return (0);
370 }
371
372 /*
373 * Check for a locked nfsnode
374 */
375 int
376 nfs_islocked(ap)
377 struct vop_islocked_args /* {
378 struct vnode *a_vp;
379 struct proc *a_p;
380 } */ *ap;
381 {
382 return VTONFS(ap->a_vp)->n_flag & NLOCKED ? 1 : 0;
383 }
384 #endif
385
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