1 /* $OpenBSD: vfs_init.c,v 1.19 2007/05/29 16:25:07 thib Exp $ */
2 /* $NetBSD: vfs_init.c,v 1.6 1996/02/09 19:00:58 christos 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
9 * to Berkeley by John Heidemann of the UCLA Ficus project.
10 *
11 * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 * @(#)vfs_init.c 8.3 (Berkeley) 1/4/94
38 */
39
40 #include <sys/param.h>
41 #include <sys/mount.h>
42 #include <sys/time.h>
43 #include <sys/vnode.h>
44 #include <sys/stat.h>
45 #include <sys/namei.h>
46 #include <sys/ucred.h>
47 #include <sys/buf.h>
48 #include <sys/errno.h>
49 #include <sys/malloc.h>
50 #include <sys/pool.h>
51 #include <sys/systm.h>
52
53 /*
54 * Sigh, such primitive tools are these...
55 */
56 #if 0
57 #define DODEBUG(A) A
58 #else
59 #define DODEBUG(A)
60 #endif
61
62 extern struct vnodeopv_desc *vfs_opv_descs[];
63 /* a list of lists of vnodeops defns */
64 extern struct vnodeop_desc *vfs_op_descs[];
65 /* and the operations they perform */
66 /*
67 * This code doesn't work if the defn is **vnodop_defns with cc.
68 * The problem is because of the compiler sometimes putting in an
69 * extra level of indirection for arrays. It's an interesting
70 * "feature" of C.
71 */
72 int vfs_opv_numops;
73
74 typedef int (*PFI)(void *);
75
76 /*
77 * A miscellaneous routine.
78 * A generic "default" routine that just returns an error.
79 */
80 /*ARGSUSED*/
81 int
82 vn_default_error(void *v)
83 {
84
85 return (EOPNOTSUPP);
86 }
87
88 /*
89 * vfs_init.c
90 *
91 * Allocate and fill in operations vectors.
92 *
93 * An undocumented feature of this approach to defining operations is that
94 * there can be multiple entries in vfs_opv_descs for the same operations
95 * vector. This allows third parties to extend the set of operations
96 * supported by another layer in a binary compatibile way. For example,
97 * assume that NFS needed to be modified to support Ficus. NFS has an entry
98 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by
99 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions)
100 * listing those new operations Ficus adds to NFS, all without modifying the
101 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but
102 * that is a(whole)nother story.) This is a feature.
103 */
104
105 /*
106 * Allocate and init the vector, if it needs it.
107 * Also handle backwards compatibility.
108 */
109 void
110 vfs_opv_init_explicit(struct vnodeopv_desc *vfs_opv_desc)
111 {
112 int (**opv_desc_vector)(void *);
113 struct vnodeopv_entry_desc *opve_descp;
114
115 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p);
116
117 if (opv_desc_vector == NULL) {
118 /* XXX - shouldn't be M_VNODE */
119 opv_desc_vector = malloc(vfs_opv_numops * sizeof(PFI),
120 M_VNODE, M_WAITOK);
121 bzero(opv_desc_vector, vfs_opv_numops * sizeof(PFI));
122 *(vfs_opv_desc->opv_desc_vector_p) = opv_desc_vector;
123 DODEBUG(printf("vector at %p allocated\n",
124 opv_desc_vector));
125 }
126
127 for (opve_descp = vfs_opv_desc->opv_desc_ops;
128 opve_descp->opve_op; opve_descp++) {
129 /*
130 * Sanity check: is this operation listed
131 * in the list of operations? We check this
132 * by seeing if its offset is zero. Since
133 * the default routine should always be listed
134 * first, it should be the only one with a zero
135 * offset. Any other operation with a zero
136 * offset is probably not listed in
137 * vfs_op_descs, and so is probably an error.
138 *
139 * A panic here means the layer programmer
140 * has committed the all-too common bug
141 * of adding a new operation to the layer's
142 * list of vnode operations but
143 * not adding the operation to the system-wide
144 * list of supported operations.
145 */
146 if (opve_descp->opve_op->vdesc_offset == 0 &&
147 opve_descp->opve_op->vdesc_offset != VOFFSET(vop_default)) {
148 printf("operation %s not listed in %s.\n",
149 opve_descp->opve_op->vdesc_name, "vfs_op_descs");
150 panic ("vfs_opv_init: bad operation");
151 }
152
153 /*
154 * Fill in this entry.
155 */
156 opv_desc_vector[opve_descp->opve_op->vdesc_offset] =
157 opve_descp->opve_impl;
158 }
159 }
160
161 void
162 vfs_opv_init_default(struct vnodeopv_desc *vfs_opv_desc)
163 {
164 int j;
165 int (**opv_desc_vector)(void *);
166
167 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p);
168
169 /*
170 * Force every operations vector to have a default routine.
171 */
172 if (opv_desc_vector[VOFFSET(vop_default)] == NULL)
173 panic("vfs_opv_init: operation vector without default routine.");
174
175 for (j = 0; j < vfs_opv_numops; j++)
176 if (opv_desc_vector[j] == NULL)
177 opv_desc_vector[j] =
178 opv_desc_vector[VOFFSET(vop_default)];
179 }
180
181 void
182 vfs_opv_init(void)
183 {
184 int i;
185
186 /*
187 * Allocate the dynamic vectors and fill them in.
188 */
189 for (i = 0; vfs_opv_descs[i]; i++)
190 vfs_opv_init_explicit(vfs_opv_descs[i]);
191
192 /*
193 * Finally, go back and replace unfilled routines
194 * with their default.
195 */
196 for (i = 0; vfs_opv_descs[i]; i++)
197 vfs_opv_init_default(vfs_opv_descs[i]);
198 }
199
200 /*
201 * Initialize known vnode operations vectors.
202 */
203 void
204 vfs_op_init(void)
205 {
206 int i;
207
208 DODEBUG(printf("Vnode_interface_init.\n"));
209 /*
210 * Set all vnode vectors to a well known value.
211 */
212 for (i = 0; vfs_opv_descs[i]; i++)
213 *(vfs_opv_descs[i]->opv_desc_vector_p) = NULL;
214 /*
215 * Figure out how many ops there are by counting the table,
216 * and assign each its offset.
217 */
218 for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) {
219 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops;
220 vfs_opv_numops++;
221 }
222 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops));
223 }
224
225 /*
226 * Routines having to do with the management of the vnode table.
227 */
228 struct pool namei_pool;
229
230 /*
231 * Initialize the vnode structures and initialize each file system type.
232 */
233 void
234 vfsinit(void)
235 {
236 int i;
237 struct vfsconf *vfsconflist;
238 int vfsconflistlen;
239
240 pool_init(&namei_pool, MAXPATHLEN, 0, 0, 0, "namei",
241 &pool_allocator_nointr);
242
243 /*
244 * Initialize the vnode table
245 */
246 vntblinit();
247 /*
248 * Initialize the vnode name cache
249 */
250 nchinit();
251 /*
252 * Build vnode operation vectors.
253 */
254 vfs_op_init();
255 vfs_opv_init(); /* finish the job */
256
257 /*
258 * Stop using vfsconf and maxvfsconf as a temporary storage,
259 * set them to their correct values now.
260 */
261 vfsconflist = vfsconf;
262 vfsconflistlen = maxvfsconf;
263 vfsconf = NULL;
264 maxvfsconf = 0;
265
266 for (i = 0; i < vfsconflistlen; i++)
267 vfs_register(&vfsconflist[i]);
268 }