xref: /freebsd/sys/kern/vfs_init.c (revision a316b26e50bbed7cf655fbba726ab87d8ab7599d)
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
6  * to Berkeley by John Heidemann of the UCLA Ficus project.
7  *
8  * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)vfs_init.c	8.3 (Berkeley) 1/4/94
39  * $Id: vfs_init.c,v 1.8 1994/10/08 22:33:42 phk Exp $
40  */
41 
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/kernel.h>
46 #include <sys/mount.h>
47 #include <sys/time.h>
48 #include <sys/vnode.h>
49 #include <sys/stat.h>
50 #include <sys/namei.h>
51 #include <sys/ucred.h>
52 #include <sys/buf.h>
53 #include <sys/errno.h>
54 #include <sys/malloc.h>
55 #include <sys/proc.h>
56 #include <vm/vm.h>
57 #include <sys/sysctl.h>
58 
59 /*
60  * Sigh, such primitive tools are these...
61  */
62 #if 0
63 #define DODEBUG(A) A
64 #else
65 #define DODEBUG(A)
66 #endif
67 
68 struct vfsconf void_vfsconf;
69 
70 extern struct linker_set vfs_opv_descs_;
71 #define vfs_opv_descs ((struct vnodeopv_desc **)vfs_opv_descs_.ls_items)
72 
73 extern struct linker_set vfs_set;
74 struct vfsops *vfssw[MOUNT_MAXTYPE + 1];
75 struct vfsconf *vfsconf[MOUNT_MAXTYPE + 1];
76 
77 extern struct vnodeop_desc *vfs_op_descs[];
78 				/* and the operations they perform */
79 /*
80  * This code doesn't work if the defn is **vnodop_defns with cc.
81  * The problem is because of the compiler sometimes putting in an
82  * extra level of indirection for arrays.  It's an interesting
83  * "feature" of C.
84  */
85 int vfs_opv_numops;
86 
87 typedef int (*PFI)(); /* the standard Pointer to a Function returning an Int */
88 
89 /*
90  * A miscellaneous routine.
91  * A generic "default" routine that just returns an error.
92  */
93 int
94 vn_default_error()
95 {
96 
97 	return (EOPNOTSUPP);
98 }
99 
100 /*
101  * vfs_init.c
102  *
103  * Allocate and fill in operations vectors.
104  *
105  * An undocumented feature of this approach to defining operations is that
106  * there can be multiple entries in vfs_opv_descs for the same operations
107  * vector. This allows third parties to extend the set of operations
108  * supported by another layer in a binary compatibile way. For example,
109  * assume that NFS needed to be modified to support Ficus. NFS has an entry
110  * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by
111  * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions)
112  * listing those new operations Ficus adds to NFS, all without modifying the
113  * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but
114  * that is a(whole)nother story.) This is a feature.
115  */
116 void
117 vfs_opv_init(struct vnodeopv_desc **them)
118 {
119 	int i, j, k;
120 	int (***opv_desc_vector_p)();
121 	int (**opv_desc_vector)();
122 	struct vnodeopv_entry_desc *opve_descp;
123 
124 	/*
125 	 * Allocate the dynamic vectors and fill them in.
126 	 */
127 	for (i=0; them[i]; i++) {
128 		opv_desc_vector_p = them[i]->opv_desc_vector_p;
129 		/*
130 		 * Allocate and init the vector, if it needs it.
131 		 * Also handle backwards compatibility.
132 		 */
133 		if (*opv_desc_vector_p == NULL) {
134 			/* XXX - shouldn't be M_VNODE */
135 			MALLOC(*opv_desc_vector_p, PFI*,
136 			       vfs_opv_numops*sizeof(PFI), M_VNODE, M_WAITOK);
137 			bzero (*opv_desc_vector_p, vfs_opv_numops*sizeof(PFI));
138 			DODEBUG(printf("vector at %x allocated\n",
139 			    opv_desc_vector_p));
140 		}
141 		opv_desc_vector = *opv_desc_vector_p;
142 		for (j=0; them[i]->opv_desc_ops[j].opve_op; j++) {
143 			opve_descp = &(them[i]->opv_desc_ops[j]);
144 
145 			/*
146 			 * Sanity check:  is this operation listed
147 			 * in the list of operations?  We check this
148 			 * by seeing if its offest is zero.  Since
149 			 * the default routine should always be listed
150 			 * first, it should be the only one with a zero
151 			 * offset.  Any other operation with a zero
152 			 * offset is probably not listed in
153 			 * vfs_op_descs, and so is probably an error.
154 			 *
155 			 * A panic here means the layer programmer
156 			 * has committed the all-too common bug
157 			 * of adding a new operation to the layer's
158 			 * list of vnode operations but
159 			 * not adding the operation to the system-wide
160 			 * list of supported operations.
161 			 */
162 			if (opve_descp->opve_op->vdesc_offset == 0 &&
163 				    opve_descp->opve_op->vdesc_offset !=
164 				    	VOFFSET(vop_default)) {
165 				printf("operation %s not listed in %s.\n",
166 				    opve_descp->opve_op->vdesc_name,
167 				    "vfs_op_descs");
168 				panic ("vfs_opv_init: bad operation");
169 			}
170 			/*
171 			 * Fill in this entry.
172 			 */
173 			opv_desc_vector[opve_descp->opve_op->vdesc_offset] =
174 					opve_descp->opve_impl;
175 		}
176 	}
177 	/*
178 	 * Finally, go back and replace unfilled routines
179 	 * with their default.  (Sigh, an O(n^3) algorithm.  I
180 	 * could make it better, but that'd be work, and n is small.)
181 	 */
182 	for (i = 0; them[i]; i++) {
183 		opv_desc_vector = *(them[i]->opv_desc_vector_p);
184 		/*
185 		 * Force every operations vector to have a default routine.
186 		 */
187 		if (opv_desc_vector[VOFFSET(vop_default)]==NULL) {
188 			panic("vfs_opv_init: operation vector without default routine.");
189 		}
190 		for (k = 0; k<vfs_opv_numops; k++)
191 			if (opv_desc_vector[k] == NULL)
192 				opv_desc_vector[k] =
193 					opv_desc_vector[VOFFSET(vop_default)];
194 	}
195 }
196 
197 /*
198  * Initialize known vnode operations vectors.
199  */
200 void
201 vfs_op_init()
202 {
203 	int i;
204 
205 	DODEBUG(printf("Vnode_interface_init.\n"));
206 	/*
207 	 * Set all vnode vectors to a well known value.
208 	 */
209 	for (i = 0; vfs_opv_descs[i]; i++)
210 		*(vfs_opv_descs[i]->opv_desc_vector_p) = NULL;
211 	/*
212 	 * Figure out how many ops there are by counting the table,
213 	 * and assign each its offset.
214 	 */
215 	for (vfs_opv_numops = 0, i = 0; vfs_op_descs[i]; i++) {
216 		vfs_op_descs[i]->vdesc_offset = vfs_opv_numops;
217 		vfs_opv_numops++;
218 	}
219 	DODEBUG(printf ("vfs_opv_numops=%d\n", vfs_opv_numops));
220 }
221 
222 /*
223  * Routines having to do with the management of the vnode table.
224  */
225 extern struct vnodeops dead_vnodeops;
226 extern struct vnodeops spec_vnodeops;
227 extern void vclean();
228 struct vattr va_null;
229 
230 /*
231  * Initialize the vnode structures and initialize each file system type.
232  */
233 void
234 vfsinit()
235 {
236 	struct vfsops **vfsp;
237 	struct vfsconf **vfc;
238 	int i;
239 
240 	/*
241 	 * Initialize the VFS switch table
242 	 */
243 	for(i = 0; i < MOUNT_MAXTYPE + 1; i++) {
244 		vfsconf[i] = &void_vfsconf;
245 	}
246 
247 	vfc = (struct vfsconf **)vfs_set.ls_items;
248 	while(*vfc) {
249 		vfssw[(**vfc).vfc_index] = (**vfc).vfc_vfsops;
250 		vfsconf[(**vfc).vfc_index] = *vfc;
251 		vfc++;
252 	}
253 
254 	/*
255 	 * Initialize the vnode table
256 	 */
257 	vntblinit();
258 	/*
259 	 * Initialize the vnode name cache
260 	 */
261 	nchinit();
262 	/*
263 	 * Build vnode operation vectors.
264 	 */
265 	vfs_op_init();
266 	vfs_opv_init(vfs_opv_descs);   /* finish the job */
267 	/*
268 	 * Initialize each file system type.
269 	 */
270 	vattr_null(&va_null);
271 	for (vfsp = &vfssw[0]; vfsp <= &vfssw[MOUNT_MAXTYPE]; vfsp++) {
272 		if (*vfsp == NULL)
273 			continue;
274 		(*(*vfsp)->vfs_init)();
275 	}
276 }
277 
278 /*
279  * kernel related system variables.
280  */
281 int
282 fs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
283 	int *name;
284 	u_int namelen;
285 	void *oldp;
286 	size_t *oldlenp;
287 	void *newp;
288 	size_t newlen;
289 	struct proc *p;
290 {
291 	int i;
292 	int error;
293 	int buflen = *oldlenp;
294 	caddr_t where = oldp, start = oldp;
295 
296 	switch (name[0]) {
297 	case FS_VFSCONF:
298 		if (namelen != 1) return ENOTDIR;
299 
300 		if (oldp == NULL) {
301 			*oldlenp = (MOUNT_MAXTYPE+1) * sizeof(struct vfsconf);
302 			return 0;
303 		}
304 		if (newp) {
305 			return EINVAL;
306 		}
307 
308 		for(i = 0; i < MOUNT_MAXTYPE + 1; i++) {
309 			if(buflen < sizeof *vfsconf[i]) {
310 				*oldlenp = where - start;
311 				return ENOMEM;
312 			}
313 
314 			error = copyout(vfsconf[i], where, sizeof *vfsconf[i]);
315 			if(error)
316 				return error;
317 			where += sizeof *vfsconf[i];
318 			buflen -= sizeof *vfsconf[i];
319 		}
320 		*oldlenp = where - start;
321 		return 0;
322 
323 	default:
324 		if(namelen < 1) return EINVAL;
325 
326 		i = name[0];
327 
328 		if(i <= MOUNT_MAXTYPE
329 		   && vfssw[i]
330 		   && vfssw[i]->vfs_sysctl) {
331 			return vfssw[i]->vfs_sysctl(name + 1, namelen - 1,
332 						    oldp, oldlenp,
333 						    newp, newlen, p);
334 		}
335 
336 		return (EOPNOTSUPP);
337 	}
338 	/* NOTREACHED */
339 }
340 
341 /*
342  * This goop is here to support a loadable NFS module... grumble...
343  */
344 void (*lease_check) __P((struct vnode *, struct proc *, struct ucred *, int))
345      = 0;
346 void (*lease_updatetime) __P((int))
347      = 0;
348 
349