vfs_init.c revision 1.13 1 /* $NetBSD: vfs_init.c,v 1.13 1998/06/24 20:58:45 sommerfe Exp $ */
2
3 /*-
4 * Copyright (c) 1998 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center.
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. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the NetBSD
22 * Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 * contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40 /*
41 * Copyright (c) 1989, 1993
42 * The Regents of the University of California. All rights reserved.
43 *
44 * This code is derived from software contributed
45 * to Berkeley by John Heidemann of the UCLA Ficus project.
46 *
47 * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project
48 *
49 * Redistribution and use in source and binary forms, with or without
50 * modification, are permitted provided that the following conditions
51 * are met:
52 * 1. Redistributions of source code must retain the above copyright
53 * notice, this list of conditions and the following disclaimer.
54 * 2. Redistributions in binary form must reproduce the above copyright
55 * notice, this list of conditions and the following disclaimer in the
56 * documentation and/or other materials provided with the distribution.
57 * 3. All advertising materials mentioning features or use of this software
58 * must display the following acknowledgement:
59 * This product includes software developed by the University of
60 * California, Berkeley and its contributors.
61 * 4. Neither the name of the University nor the names of its contributors
62 * may be used to endorse or promote products derived from this software
63 * without specific prior written permission.
64 *
65 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
66 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
67 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
68 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
69 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
70 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
71 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
72 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
73 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
74 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
75 * SUCH DAMAGE.
76 *
77 * @(#)vfs_init.c 8.5 (Berkeley) 5/11/95
78 */
79
80 #include <sys/param.h>
81 #include <sys/mount.h>
82 #include <sys/time.h>
83 #include <sys/vnode.h>
84 #include <sys/stat.h>
85 #include <sys/namei.h>
86 #include <sys/ucred.h>
87 #include <sys/buf.h>
88 #include <sys/errno.h>
89 #include <sys/malloc.h>
90 #include <sys/systm.h>
91
92 /*
93 * Sigh, such primitive tools are these...
94 */
95 #if 0
96 #define DODEBUG(A) A
97 #else
98 #define DODEBUG(A)
99 #endif
100
101 /*
102 * The global list of vnode operations.
103 */
104 extern struct vnodeop_desc *vfs_op_descs[];
105
106 /*
107 * These vnodeopv_descs are listed here because they are not
108 * associated with any particular file system, and thus cannot
109 * be initialized by vfs_attach().
110 */
111 extern struct vnodeopv_desc dead_vnodeop_opv_desc;
112 extern struct vnodeopv_desc fifo_vnodeop_opv_desc;
113 extern struct vnodeopv_desc spec_vnodeop_opv_desc;
114
115 struct vnodeopv_desc *vfs_special_vnodeopv_descs[] = {
116 &dead_vnodeop_opv_desc,
117 &fifo_vnodeop_opv_desc,
118 &spec_vnodeop_opv_desc,
119 NULL,
120 };
121
122 /*
123 * This code doesn't work if the defn is **vnodop_defns with cc.
124 * The problem is because of the compiler sometimes putting in an
125 * extra level of indirection for arrays. It's an interesting
126 * "feature" of C.
127 */
128 int vfs_opv_numops;
129
130 typedef int (*PFI) __P((void *));
131
132 void vfs_opv_init_explicit __P((struct vnodeopv_desc *));
133 void vfs_opv_init_default __P((struct vnodeopv_desc *));
134 void vfs_op_init __P((void));
135
136 /*
137 * A miscellaneous routine.
138 * A generic "default" routine that just returns an error.
139 */
140 /*ARGSUSED*/
141 int
142 vn_default_error(v)
143 void *v;
144 {
145
146 return (EOPNOTSUPP);
147 }
148
149 /*
150 * vfs_init.c
151 *
152 * Allocate and fill in operations vectors.
153 *
154 * An undocumented feature of this approach to defining operations is that
155 * there can be multiple entries in vfs_opv_descs for the same operations
156 * vector. This allows third parties to extend the set of operations
157 * supported by another layer in a binary compatibile way. For example,
158 * assume that NFS needed to be modified to support Ficus. NFS has an entry
159 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by
160 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions)
161 * listing those new operations Ficus adds to NFS, all without modifying the
162 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but
163 * that is a(whole)nother story.) This is a feature.
164 */
165
166 /*
167 * Init the vector, if it needs it.
168 * Also handle backwards compatibility.
169 */
170 void
171 vfs_opv_init_explicit(vfs_opv_desc)
172 struct vnodeopv_desc *vfs_opv_desc;
173 {
174 int (**opv_desc_vector) __P((void *));
175 struct vnodeopv_entry_desc *opve_descp;
176
177 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p);
178
179 for (opve_descp = vfs_opv_desc->opv_desc_ops;
180 opve_descp->opve_op;
181 opve_descp++) {
182 /*
183 * Sanity check: is this operation listed
184 * in the list of operations? We check this
185 * by seeing if its offest is zero. Since
186 * the default routine should always be listed
187 * first, it should be the only one with a zero
188 * offset. Any other operation with a zero
189 * offset is probably not listed in
190 * vfs_op_descs, and so is probably an error.
191 *
192 * A panic here means the layer programmer
193 * has committed the all-too common bug
194 * of adding a new operation to the layer's
195 * list of vnode operations but
196 * not adding the operation to the system-wide
197 * list of supported operations.
198 */
199 if (opve_descp->opve_op->vdesc_offset == 0 &&
200 opve_descp->opve_op->vdesc_offset != VOFFSET(vop_default)) {
201 printf("operation %s not listed in %s.\n",
202 opve_descp->opve_op->vdesc_name, "vfs_op_descs");
203 panic ("vfs_opv_init: bad operation");
204 }
205
206 /*
207 * Fill in this entry.
208 */
209 opv_desc_vector[opve_descp->opve_op->vdesc_offset] =
210 opve_descp->opve_impl;
211 }
212 }
213
214 void
215 vfs_opv_init_default(vfs_opv_desc)
216 struct vnodeopv_desc *vfs_opv_desc;
217 {
218 int j;
219 int (**opv_desc_vector) __P((void *));
220
221 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p);
222
223 /*
224 * Force every operations vector to have a default routine.
225 */
226 if (opv_desc_vector[VOFFSET(vop_default)] == NULL)
227 panic("vfs_opv_init: operation vector without default routine.");
228
229 for (j = 0; j < vfs_opv_numops; j++)
230 if (opv_desc_vector[j] == NULL)
231 opv_desc_vector[j] =
232 opv_desc_vector[VOFFSET(vop_default)];
233 }
234
235 void
236 vfs_opv_init(vopvdpp)
237 struct vnodeopv_desc **vopvdpp;
238 {
239 int (**opv_desc_vector) __P((void *));
240 int i;
241
242 /*
243 * Allocate the vectors.
244 */
245 for (i = 0; vopvdpp[i] != NULL; i++) {
246 /* XXX - shouldn't be M_VNODE */
247 opv_desc_vector =
248 malloc(vfs_opv_numops * sizeof(PFI), M_VNODE, M_WAITOK);
249 bzero(opv_desc_vector, vfs_opv_numops * sizeof(PFI));
250 *(vopvdpp[i]->opv_desc_vector_p) = opv_desc_vector;
251 DODEBUG(printf("vector at %p allocated\n",
252 opv_desc_vector_p));
253 }
254
255 /*
256 * ...and fill them in.
257 */
258 for (i = 0; vopvdpp[i] != NULL; i++)
259 vfs_opv_init_explicit(vopvdpp[i]);
260
261 /*
262 * Finally, go back and replace unfilled routines
263 * with their default.
264 */
265 for (i = 0; vopvdpp[i] != NULL; i++)
266 vfs_opv_init_default(vopvdpp[i]);
267 }
268
269 void
270 vfs_opv_free(vopvdpp)
271 struct vnodeopv_desc **vopvdpp;
272 {
273 int i;
274
275 /*
276 * Free the vectors allocated in vfs_opv_init().
277 */
278 for (i = 0; vopvdpp[i] != NULL; i++) {
279 /* XXX - shouldn't be M_VNODE */
280 free(*(vopvdpp[i]->opv_desc_vector_p), M_VNODE);
281 *(vopvdpp[i]->opv_desc_vector_p) = NULL;
282 }
283 }
284
285 void
286 vfs_op_init()
287 {
288 int i;
289
290 DODEBUG(printf("Vnode_interface_init.\n"));
291 /*
292 * Figure out how many ops there are by counting the table,
293 * and assign each its offset.
294 */
295 for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) {
296 vfs_op_descs[i]->vdesc_offset = vfs_opv_numops;
297 vfs_opv_numops++;
298 }
299 DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops));
300 }
301
302 /*
303 * Routines having to do with the management of the vnode table.
304 */
305 struct vattr va_null;
306
307 /*
308 * Initialize the vnode structures and initialize each file system type.
309 */
310 void
311 vfsinit()
312 {
313 extern struct vfsops *vfs_list_initial[];
314 int i;
315
316 /*
317 * Initialize the vnode table
318 */
319 vntblinit();
320
321 /*
322 * Initialize the vnode name cache
323 */
324 nchinit();
325
326 /*
327 * Initialize the list of vnode operations.
328 */
329 vfs_op_init();
330
331 /*
332 * Initialize the special vnode operations.
333 */
334 vfs_opv_init(vfs_special_vnodeopv_descs);
335
336 /*
337 * Establish each file system which was statically
338 * included in the kernel.
339 */
340 vattr_null(&va_null);
341 for (i = 0; vfs_list_initial[i] != NULL; i++) {
342 if (vfs_attach(vfs_list_initial[i])) {
343 printf("multiple `%s' file systems",
344 vfs_list_initial[i]->vfs_name);
345 panic("vfsinit");
346 }
347 }
348 }
349