xref: /openbsd-src/sys/nfs/nfs_node.c (revision 43003dfe3ad45d1698bed8a37f2b0f5b14f20d4f)
1 /*	$OpenBSD: nfs_node.c,v 1.48 2009/08/14 17:52:18 thib Exp $	*/
2 /*	$NetBSD: nfs_node.c,v 1.16 1996/02/18 11:53:42 fvdl Exp $	*/
3 
4 /*
5  * Copyright (c) 1989, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Rick Macklem at The University of Guelph.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)nfs_node.c	8.6 (Berkeley) 5/22/95
36  */
37 
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/proc.h>
42 #include <sys/mount.h>
43 #include <sys/namei.h>
44 #include <sys/vnode.h>
45 #include <sys/kernel.h>
46 #include <sys/malloc.h>
47 #include <sys/pool.h>
48 #include <sys/rwlock.h>
49 #include <sys/queue.h>
50 
51 #include <nfs/rpcv2.h>
52 #include <nfs/nfsproto.h>
53 #include <nfs/nfs.h>
54 #include <nfs/nfsnode.h>
55 #include <nfs/nfsmount.h>
56 #include <nfs/nfs_var.h>
57 
58 struct pool nfs_node_pool;
59 extern int prtactive;
60 
61 struct rwlock nfs_hashlock = RWLOCK_INITIALIZER("nfshshlk");
62 
63 /* filehandle to node lookup. */
64 static __inline int
65 nfsnode_cmp(const struct nfsnode *a, const struct nfsnode *b)
66 {
67 	if (a->n_fhsize != b->n_fhsize)
68 		return (a->n_fhsize - b->n_fhsize);
69 	return (memcmp(a->n_fhp, b->n_fhp, a->n_fhsize));
70 }
71 
72 RB_PROTOTYPE(nfs_nodetree, nfsnode, n_entry, nfsnode_cmp);
73 RB_GENERATE(nfs_nodetree, nfsnode, n_entry, nfsnode_cmp);
74 
75 /*
76  * Look up a vnode/nfsnode by file handle.
77  * Callers must check for mount points!!
78  * In all cases, a pointer to a
79  * nfsnode structure is returned.
80  */
81 int
82 nfs_nget(struct mount *mnt, nfsfh_t *fh, int fhsize, struct nfsnode **npp)
83 {
84 	extern int (**nfsv2_vnodeop_p)(void *);		/* XXX */
85 	struct nfsmount		*nmp;
86 	struct nfsnode		*np, find, *np2;
87 	struct vnode		*vp, *nvp;
88 	struct proc		*p = curproc;		/* XXX */
89 	int			 error;
90 
91 	nmp = VFSTONFS(mnt);
92 
93 loop:
94 	rw_enter_write(&nfs_hashlock);
95 	find.n_fhp = fh;
96 	find.n_fhsize = fhsize;
97 	np = RB_FIND(nfs_nodetree, &nmp->nm_ntree, &find);
98 	if (np != NULL) {
99 		rw_exit_write(&nfs_hashlock);
100 		vp = NFSTOV(np);
101 		error = vget(vp, LK_EXCLUSIVE, p);
102 		if (error)
103 			goto loop;
104 		*npp = np;
105 		return (0);
106 	}
107 
108 	/*
109 	 * getnewvnode() could recycle a vnode, potentially formerly
110 	 * owned by NFS. This will cause a VOP_RECLAIM() to happen,
111 	 * which will cause recursive locking, so we unlock before
112 	 * calling getnewvnode() lock again afterwards, but must check
113 	 * to see if this nfsnode has been added while we did not hold
114 	 * the lock.
115 	 */
116 	rw_exit_write(&nfs_hashlock);
117 	error = getnewvnode(VT_NFS, mnt, nfsv2_vnodeop_p, &nvp);
118 	rw_enter_write(&nfs_hashlock);
119 	if (error) {
120 		*npp = NULL;
121 		rw_exit_write(&nfs_hashlock);
122 		return (error);
123 	}
124 
125 	np = RB_FIND(nfs_nodetree, &nmp->nm_ntree, &find);
126 	if (np != NULL) {
127 		rw_exit_write(&nfs_hashlock);
128 		goto loop;
129 	}
130 
131 	vp = nvp;
132 	np = pool_get(&nfs_node_pool, PR_WAITOK | PR_ZERO);
133 	vp->v_data = np;
134 	np->n_vnode = vp;
135 
136 	rw_init(&np->n_commitlock, "nfs_commitlk");
137 
138 	/*
139 	 * Are we getting the root? If so, make sure the vnode flags
140 	 * are correct
141 	 */
142 	if ((fhsize == nmp->nm_fhsize) && !bcmp(fh, nmp->nm_fh, fhsize)) {
143 		if (vp->v_type == VNON)
144 			vp->v_type = VDIR;
145 		vp->v_flag |= VROOT;
146 	}
147 
148 	np->n_fhp = &np->n_fh;
149 	bcopy(fh, np->n_fhp, fhsize);
150 	np->n_fhsize = fhsize;
151 	np2 = RB_INSERT(nfs_nodetree, &nmp->nm_ntree, np);
152 	KASSERT(np2 == NULL);
153 	np->n_accstamp = -1;
154 	rw_exit(&nfs_hashlock);
155 	*npp = np;
156 
157 	return (0);
158 }
159 
160 int
161 nfs_inactive(void *v)
162 {
163 	struct vop_inactive_args	*ap = v;
164 	struct nfsnode			*np = VTONFS(ap->a_vp);
165 	struct sillyrename		*sp;
166 
167 #ifdef DIAGNOSTIC
168 	if (prtactive && ap->a_vp->v_usecount != 0)
169 		vprint("nfs_inactive: pushing active", ap->a_vp);
170 #endif
171 
172 	if (ap->a_vp->v_type != VDIR) {
173 		sp = np->n_sillyrename;
174 		np->n_sillyrename = NULL;
175 	} else
176 		sp = NULL;
177 	if (sp) {
178 		/*
179 		 * Remove the silly file that was rename'd earlier
180 		 */
181 		nfs_vinvalbuf(ap->a_vp, 0, sp->s_cred, curproc);
182 		nfs_removeit(sp);
183 		crfree(sp->s_cred);
184 		vrele(sp->s_dvp);
185 		free(sp, M_NFSREQ);
186 	}
187 	np->n_flag &= (NMODIFIED | NFLUSHINPROG | NFLUSHWANT);
188 
189 	VOP_UNLOCK(ap->a_vp, 0, ap->a_p);
190 	return (0);
191 }
192 
193 /*
194  * Reclaim an nfsnode so that it can be used for other purposes.
195  */
196 int
197 nfs_reclaim(void *v)
198 {
199 	struct vop_reclaim_args	*ap = v;
200 	struct vnode		*vp = ap->a_vp;
201 	struct nfsmount		*nmp = VFSTONFS(vp->v_mount);
202 	struct nfsnode		*np = VTONFS(vp);
203 
204 #ifdef DIAGNOSTIC
205 	if (prtactive && vp->v_usecount != 0)
206 		vprint("nfs_reclaim: pushing active", vp);
207 #endif
208 
209 	rw_enter_write(&nfs_hashlock);
210 	RB_REMOVE(nfs_nodetree, &nmp->nm_ntree, np);
211 	rw_exit_write(&nfs_hashlock);
212 
213 	if (np->n_rcred)
214 		crfree(np->n_rcred);
215 	if (np->n_wcred)
216 		crfree(np->n_wcred);
217 
218 	cache_purge(vp);
219 	pool_put(&nfs_node_pool, vp->v_data);
220 	vp->v_data = NULL;
221 
222 	return (0);
223 }
224