xref: /netbsd/sys/kern/vfs_init.c (revision c4a72b64)
1 /*	$NetBSD: vfs_init.c,v 1.22 2002/09/26 04:07:35 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (c) 1998, 2000 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/cdefs.h>
81 __KERNEL_RCSID(0, "$NetBSD: vfs_init.c,v 1.22 2002/09/26 04:07:35 thorpej Exp $");
82 
83 #include <sys/param.h>
84 #include <sys/mount.h>
85 #include <sys/time.h>
86 #include <sys/vnode.h>
87 #include <sys/stat.h>
88 #include <sys/namei.h>
89 #include <sys/ucred.h>
90 #include <sys/buf.h>
91 #include <sys/errno.h>
92 #include <sys/malloc.h>
93 #include <sys/systm.h>
94 
95 /*
96  * Sigh, such primitive tools are these...
97  */
98 #if 0
99 #define DODEBUG(A) A
100 #else
101 #define DODEBUG(A)
102 #endif
103 
104 /*
105  * The global list of vnode operations.
106  */
107 extern const struct vnodeop_desc * const vfs_op_descs[];
108 
109 /*
110  * These vnodeopv_descs are listed here because they are not
111  * associated with any particular file system, and thus cannot
112  * be initialized by vfs_attach().
113  */
114 extern const struct vnodeopv_desc dead_vnodeop_opv_desc;
115 extern const struct vnodeopv_desc fifo_vnodeop_opv_desc;
116 extern const struct vnodeopv_desc spec_vnodeop_opv_desc;
117 extern const struct vnodeopv_desc sync_vnodeop_opv_desc;
118 
119 const struct vnodeopv_desc * const vfs_special_vnodeopv_descs[] = {
120 	&dead_vnodeop_opv_desc,
121 	&fifo_vnodeop_opv_desc,
122 	&spec_vnodeop_opv_desc,
123 	&sync_vnodeop_opv_desc,
124 	NULL,
125 };
126 
127 /*
128  * This code doesn't work if the defn is **vnodop_defns with cc.
129  * The problem is because of the compiler sometimes putting in an
130  * extra level of indirection for arrays.  It's an interesting
131  * "feature" of C.
132  */
133 typedef int (*PFI) __P((void *));
134 
135 static void vfs_opv_init_explicit __P((const struct vnodeopv_desc *));
136 static void vfs_opv_init_default __P((const struct vnodeopv_desc *));
137 #ifdef DEBUG
138 static void vfs_op_check __P((void));
139 #endif
140 
141 /*
142  * A miscellaneous routine.
143  * A generic "default" routine that just returns an error.
144  */
145 /*ARGSUSED*/
146 int
147 vn_default_error(v)
148 	void *v;
149 {
150 
151 	return (EOPNOTSUPP);
152 }
153 
154 /*
155  * vfs_init.c
156  *
157  * Allocate and fill in operations vectors.
158  *
159  * An undocumented feature of this approach to defining operations is that
160  * there can be multiple entries in vfs_opv_descs for the same operations
161  * vector. This allows third parties to extend the set of operations
162  * supported by another layer in a binary compatibile way. For example,
163  * assume that NFS needed to be modified to support Ficus. NFS has an entry
164  * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by
165  * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions)
166  * listing those new operations Ficus adds to NFS, all without modifying the
167  * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but
168  * that is a(whole)nother story.) This is a feature.
169  */
170 
171 /*
172  * Init the vector, if it needs it.
173  * Also handle backwards compatibility.
174  */
175 static void
176 vfs_opv_init_explicit(vfs_opv_desc)
177 	const struct vnodeopv_desc *vfs_opv_desc;
178 {
179 	int (**opv_desc_vector) __P((void *));
180 	const struct vnodeopv_entry_desc *opve_descp;
181 
182 	opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p);
183 
184 	for (opve_descp = vfs_opv_desc->opv_desc_ops;
185 	     opve_descp->opve_op;
186 	     opve_descp++) {
187 		/*
188 		 * Sanity check:  is this operation listed
189 		 * in the list of operations?  We check this
190 		 * by seeing if its offest is zero.  Since
191 		 * the default routine should always be listed
192 		 * first, it should be the only one with a zero
193 		 * offset.  Any other operation with a zero
194 		 * offset is probably not listed in
195 		 * vfs_op_descs, and so is probably an error.
196 		 *
197 		 * A panic here means the layer programmer
198 		 * has committed the all-too common bug
199 		 * of adding a new operation to the layer's
200 		 * list of vnode operations but
201 		 * not adding the operation to the system-wide
202 		 * list of supported operations.
203 		 */
204 		if (opve_descp->opve_op->vdesc_offset == 0 &&
205 		    opve_descp->opve_op->vdesc_offset != VOFFSET(vop_default)) {
206 			printf("operation %s not listed in %s.\n",
207 			    opve_descp->opve_op->vdesc_name, "vfs_op_descs");
208 			panic ("vfs_opv_init: bad operation");
209 		}
210 
211 		/*
212 		 * Fill in this entry.
213 		 */
214 		opv_desc_vector[opve_descp->opve_op->vdesc_offset] =
215 		    opve_descp->opve_impl;
216 	}
217 }
218 
219 static void
220 vfs_opv_init_default(vfs_opv_desc)
221 	const struct vnodeopv_desc *vfs_opv_desc;
222 {
223 	int j;
224 	int (**opv_desc_vector) __P((void *));
225 
226 	opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p);
227 
228 	/*
229 	 * Force every operations vector to have a default routine.
230 	 */
231 	if (opv_desc_vector[VOFFSET(vop_default)] == NULL)
232 		panic("vfs_opv_init: operation vector without default routine.");
233 
234 	for (j = 0; j < VNODE_OPS_COUNT; j++)
235 		if (opv_desc_vector[j] == NULL)
236 			opv_desc_vector[j] =
237 			    opv_desc_vector[VOFFSET(vop_default)];
238 }
239 
240 void
241 vfs_opv_init(vopvdpp)
242 	const struct vnodeopv_desc * const *vopvdpp;
243 {
244 	int (**opv_desc_vector) __P((void *));
245 	int i;
246 
247 	/*
248 	 * Allocate the vectors.
249 	 */
250 	for (i = 0; vopvdpp[i] != NULL; i++) {
251 		/* XXX - shouldn't be M_VNODE */
252 		opv_desc_vector =
253 		    malloc(VNODE_OPS_COUNT * sizeof(PFI), M_VNODE, M_WAITOK);
254 		memset(opv_desc_vector, 0, VNODE_OPS_COUNT * sizeof(PFI));
255 		*(vopvdpp[i]->opv_desc_vector_p) = opv_desc_vector;
256 		DODEBUG(printf("vector at %p allocated\n",
257 		    opv_desc_vector_p));
258 	}
259 
260 	/*
261 	 * ...and fill them in.
262 	 */
263 	for (i = 0; vopvdpp[i] != NULL; i++)
264 		vfs_opv_init_explicit(vopvdpp[i]);
265 
266 	/*
267 	 * Finally, go back and replace unfilled routines
268 	 * with their default.
269 	 */
270 	for (i = 0; vopvdpp[i] != NULL; i++)
271 		vfs_opv_init_default(vopvdpp[i]);
272 }
273 
274 void
275 vfs_opv_free(vopvdpp)
276 	const struct vnodeopv_desc * const *vopvdpp;
277 {
278 	int i;
279 
280 	/*
281 	 * Free the vectors allocated in vfs_opv_init().
282 	 */
283 	for (i = 0; vopvdpp[i] != NULL; i++) {
284 		/* XXX - shouldn't be M_VNODE */
285 		free(*(vopvdpp[i]->opv_desc_vector_p), M_VNODE);
286 		*(vopvdpp[i]->opv_desc_vector_p) = NULL;
287 	}
288 }
289 
290 #ifdef DEBUG
291 static void
292 vfs_op_check()
293 {
294 	int i;
295 
296 	DODEBUG(printf("Vnode_interface_init.\n"));
297 
298 	/*
299 	 * Check offset of each op.
300 	 */
301 	for (i = 0; vfs_op_descs[i]; i++) {
302 		if (vfs_op_descs[i]->vdesc_offset != i)
303 			panic("vfs_op_check: vfs_op_desc[] offset mismatch");
304 	}
305 
306 	if (i != VNODE_OPS_COUNT) {
307 		panic("vfs_op_check: vnode ops count mismatch (%d != %d)",
308 			i, VNODE_OPS_COUNT);
309 	}
310 
311 	DODEBUG(printf ("vfs_opv_numops=%d\n", VNODE_OPS_COUNT));
312 }
313 #endif /* DEBUG */
314 
315 /*
316  * Routines having to do with the management of the vnode table.
317  */
318 struct vattr va_null;
319 
320 /*
321  * Initialize the vnode structures and initialize each file system type.
322  */
323 void
324 vfsinit()
325 {
326 	extern struct vfsops * const vfs_list_initial[];
327 	int i;
328 
329 	/*
330 	 * Initialize the namei pathname buffer pool and cache.
331 	 */
332 	pool_init(&pnbuf_pool, MAXPATHLEN, 0, 0, 0, "pnbufpl",
333 	     &pool_allocator_nointr);
334 	pool_cache_init(&pnbuf_cache, &pnbuf_pool, NULL, NULL, NULL);
335 
336 	/*
337 	 * Initialize the vnode table
338 	 */
339 	vntblinit();
340 
341 	/*
342 	 * Initialize the vnode name cache
343 	 */
344 	nchinit();
345 
346 #ifdef DEBUG
347 	/*
348 	 * Check the list of vnode operations.
349 	 */
350 	vfs_op_check();
351 #endif
352 
353 	/*
354 	 * Initialize the special vnode operations.
355 	 */
356 	vfs_opv_init(vfs_special_vnodeopv_descs);
357 
358 	/*
359 	 * Establish each file system which was statically
360 	 * included in the kernel.
361 	 */
362 	vattr_null(&va_null);
363 	for (i = 0; vfs_list_initial[i] != NULL; i++) {
364 		if (vfs_attach(vfs_list_initial[i])) {
365 			printf("multiple `%s' file systems",
366 			    vfs_list_initial[i]->vfs_name);
367 			panic("vfsinit");
368 		}
369 	}
370 }
371