xref: /netbsd-src/sys/miscfs/kernfs/kernfs_vfsops.c (revision 28c37e673e4d9b6cbdc7483062b915cc61d1ccf5)
1 /*	$NetBSD: kernfs_vfsops.c,v 1.46 2002/09/21 18:09:29 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1992, 1993, 1995
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software donated to Berkeley by
8  * Jan-Simon Pendry.
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  *	@(#)kernfs_vfsops.c	8.10 (Berkeley) 5/14/95
39  */
40 
41 /*
42  * Kernel params Filesystem
43  */
44 
45 #include <sys/cdefs.h>
46 __KERNEL_RCSID(0, "$NetBSD: kernfs_vfsops.c,v 1.46 2002/09/21 18:09:29 christos Exp $");
47 
48 #if defined(_KERNEL_OPT)
49 #include "opt_compat_netbsd.h"
50 #endif
51 
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/conf.h>
55 #include <sys/proc.h>
56 #include <sys/vnode.h>
57 #include <sys/mount.h>
58 #include <sys/namei.h>
59 #include <sys/malloc.h>
60 
61 #include <miscfs/specfs/specdev.h>
62 #include <miscfs/kernfs/kernfs.h>
63 
64 dev_t rrootdev = NODEV;
65 
66 void	kernfs_init __P((void));
67 void	kernfs_done __P((void));
68 void	kernfs_get_rrootdev __P((void));
69 int	kernfs_mount __P((struct mount *, const char *, void *,
70 	    struct nameidata *, struct proc *));
71 int	kernfs_start __P((struct mount *, int, struct proc *));
72 int	kernfs_unmount __P((struct mount *, int, struct proc *));
73 int	kernfs_root __P((struct mount *, struct vnode **));
74 int	kernfs_statfs __P((struct mount *, struct statfs *, struct proc *));
75 int	kernfs_quotactl __P((struct mount *, int, uid_t, caddr_t,
76 			     struct proc *));
77 int	kernfs_sync __P((struct mount *, int, struct ucred *, struct proc *));
78 int	kernfs_vget __P((struct mount *, ino_t, struct vnode **));
79 int	kernfs_fhtovp __P((struct mount *, struct fid *, struct vnode **));
80 int	kernfs_checkexp __P((struct mount *, struct mbuf *, int *,
81 			   struct ucred **));
82 int	kernfs_vptofh __P((struct vnode *, struct fid *));
83 int	kernfs_sysctl __P((int *, u_int, void *, size_t *, void *, size_t,
84 			   struct proc *));
85 
86 void
87 kernfs_init()
88 {
89 }
90 
91 void
92 kernfs_done()
93 {
94 }
95 
96 void
97 kernfs_get_rrootdev()
98 {
99 	static int tried = 0;
100 
101 	if (tried) {
102 		/* Already did it once. */
103 		return;
104 	}
105 	tried = 1;
106 
107 	if (rootdev == NODEV)
108 		return;
109 	rrootdev = devsw_blk2chr(rootdev);
110 	if (rrootdev != NODEV) {
111 #ifdef KERNFS_DIAGNOSTIC
112 	printf("kernfs_mount: rootdev = %u.%u; rrootdev = %u.%u\n",
113 	    major(rootdev), minor(rootdev), major(rrootdev), minor(rrootdev));
114 #endif
115 		return;
116 	}
117 	rrootdev = NODEV;
118 	printf("kernfs_get_rrootdev: no raw root device\n");
119 }
120 
121 /*
122  * Mount the Kernel params filesystem
123  */
124 int
125 kernfs_mount(mp, path, data, ndp, p)
126 	struct mount *mp;
127 	const char *path;
128 	void *data;
129 	struct nameidata *ndp;
130 	struct proc *p;
131 {
132 	int error = 0;
133 	size_t size;
134 	struct kernfs_mount *fmp;
135 	struct vnode *rvp;
136 
137 #ifdef KERNFS_DIAGNOSTIC
138 	printf("kernfs_mount(mp = %p)\n", mp);
139 #endif
140 
141 	if (mp->mnt_flag & MNT_GETARGS)
142 		return 0;
143 	/*
144 	 * Update is a no-op
145 	 */
146 	if (mp->mnt_flag & MNT_UPDATE)
147 		return (EOPNOTSUPP);
148 
149 	error = getnewvnode(VT_KERNFS, mp, kernfs_vnodeop_p, &rvp);
150 	if (error)
151 		return (error);
152 
153 	MALLOC(fmp, struct kernfs_mount *, sizeof(struct kernfs_mount),
154 	    M_MISCFSMNT, M_WAITOK);
155 	rvp->v_type = VDIR;
156 	rvp->v_flag |= VROOT;
157 #ifdef KERNFS_DIAGNOSTIC
158 	printf("kernfs_mount: root vp = %p\n", rvp);
159 #endif
160 	fmp->kf_root = rvp;
161 	mp->mnt_flag |= MNT_LOCAL;
162 	mp->mnt_data = fmp;
163 	vfs_getnewfsid(mp);
164 
165 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
166 	memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size);
167 	memset(mp->mnt_stat.f_mntfromname, 0, MNAMELEN);
168 	memcpy(mp->mnt_stat.f_mntfromname, "kernfs", sizeof("kernfs"));
169 #ifdef KERNFS_DIAGNOSTIC
170 	printf("kernfs_mount: at %s\n", mp->mnt_stat.f_mntonname);
171 #endif
172 
173 	kernfs_get_rrootdev();
174 	return (0);
175 }
176 
177 int
178 kernfs_start(mp, flags, p)
179 	struct mount *mp;
180 	int flags;
181 	struct proc *p;
182 {
183 
184 	return (0);
185 }
186 
187 int
188 kernfs_unmount(mp, mntflags, p)
189 	struct mount *mp;
190 	int mntflags;
191 	struct proc *p;
192 {
193 	int error;
194 	int flags = 0;
195 	struct vnode *rootvp = VFSTOKERNFS(mp)->kf_root;
196 
197 #ifdef KERNFS_DIAGNOSTIC
198 	printf("kernfs_unmount(mp = %p)\n", mp);
199 #endif
200 
201 	 if (mntflags & MNT_FORCE)
202 		flags |= FORCECLOSE;
203 
204 	/*
205 	 * Clear out buffer cache.  I don't think we
206 	 * ever get anything cached at this level at the
207 	 * moment, but who knows...
208 	 */
209 	if (rootvp->v_usecount > 1)
210 		return (EBUSY);
211 #ifdef KERNFS_DIAGNOSTIC
212 	printf("kernfs_unmount: calling vflush\n");
213 #endif
214 	if ((error = vflush(mp, rootvp, flags)) != 0)
215 		return (error);
216 
217 #ifdef KERNFS_DIAGNOSTIC
218 	vprint("kernfs root", rootvp);
219 #endif
220 	/*
221 	 * Clean out the old root vnode for reuse.
222 	 */
223 	vrele(rootvp);
224 	vgone(rootvp);
225 	/*
226 	 * Finally, throw away the kernfs_mount structure
227 	 */
228 	free(mp->mnt_data, M_MISCFSMNT);
229 	mp->mnt_data = 0;
230 	return (0);
231 }
232 
233 int
234 kernfs_root(mp, vpp)
235 	struct mount *mp;
236 	struct vnode **vpp;
237 {
238 	struct vnode *vp;
239 
240 #ifdef KERNFS_DIAGNOSTIC
241 	printf("kernfs_root(mp = %p)\n", mp);
242 #endif
243 
244 	/*
245 	 * Return locked reference to root.
246 	 */
247 	vp = VFSTOKERNFS(mp)->kf_root;
248 	VREF(vp);
249 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
250 	*vpp = vp;
251 	return (0);
252 }
253 
254 int
255 kernfs_quotactl(mp, cmd, uid, arg, p)
256 	struct mount *mp;
257 	int cmd;
258 	uid_t uid;
259 	caddr_t arg;
260 	struct proc *p;
261 {
262 
263 	return (EOPNOTSUPP);
264 }
265 
266 int
267 kernfs_statfs(mp, sbp, p)
268 	struct mount *mp;
269 	struct statfs *sbp;
270 	struct proc *p;
271 {
272 
273 #ifdef KERNFS_DIAGNOSTIC
274 	printf("kernfs_statfs(mp = %p)\n", mp);
275 #endif
276 
277 	sbp->f_bsize = DEV_BSIZE;
278 	sbp->f_iosize = DEV_BSIZE;
279 	sbp->f_blocks = 2;		/* 1K to keep df happy */
280 	sbp->f_bfree = 0;
281 	sbp->f_bavail = 0;
282 	sbp->f_files = 0;
283 	sbp->f_ffree = 0;
284 #ifdef COMPAT_09
285 	sbp->f_type = 7;
286 #else
287 	sbp->f_type = 0;
288 #endif
289 	if (sbp != &mp->mnt_stat) {
290 		memcpy(&sbp->f_fsid, &mp->mnt_stat.f_fsid, sizeof(sbp->f_fsid));
291 		memcpy(sbp->f_mntonname, mp->mnt_stat.f_mntonname, MNAMELEN);
292 		memcpy(sbp->f_mntfromname, mp->mnt_stat.f_mntfromname, MNAMELEN);
293 	}
294 	strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, MFSNAMELEN);
295 	return (0);
296 }
297 
298 /*ARGSUSED*/
299 int
300 kernfs_sync(mp, waitfor, uc, p)
301 	struct mount *mp;
302 	int waitfor;
303 	struct ucred *uc;
304 	struct proc *p;
305 {
306 
307 	return (0);
308 }
309 
310 /*
311  * Kernfs flat namespace lookup.
312  * Currently unsupported.
313  */
314 int
315 kernfs_vget(mp, ino, vpp)
316 	struct mount *mp;
317 	ino_t ino;
318 	struct vnode **vpp;
319 {
320 
321 	return (EOPNOTSUPP);
322 }
323 
324 /*ARGSUSED*/
325 int
326 kernfs_fhtovp(mp, fhp, vpp)
327 	struct mount *mp;
328 	struct fid *fhp;
329 	struct vnode **vpp;
330 {
331 
332 	return (EOPNOTSUPP);
333 }
334 
335 /*ARGSUSED*/
336 int
337 kernfs_checkexp(mp, mb, what, anon)
338 	struct mount *mp;
339 	struct mbuf *mb;
340 	int *what;
341 	struct ucred **anon;
342 {
343 
344 	return (EOPNOTSUPP);
345 }
346 
347 /*ARGSUSED*/
348 int
349 kernfs_vptofh(vp, fhp)
350 	struct vnode *vp;
351 	struct fid *fhp;
352 {
353 
354 	return (EOPNOTSUPP);
355 }
356 
357 int
358 kernfs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
359 	int *name;
360 	u_int namelen;
361 	void *oldp;
362 	size_t *oldlenp;
363 	void *newp;
364 	size_t newlen;
365 	struct proc *p;
366 {
367 	return (EOPNOTSUPP);
368 }
369 
370 extern const struct vnodeopv_desc kernfs_vnodeop_opv_desc;
371 
372 const struct vnodeopv_desc * const kernfs_vnodeopv_descs[] = {
373 	&kernfs_vnodeop_opv_desc,
374 	NULL,
375 };
376 
377 struct vfsops kernfs_vfsops = {
378 	MOUNT_KERNFS,
379 	kernfs_mount,
380 	kernfs_start,
381 	kernfs_unmount,
382 	kernfs_root,
383 	kernfs_quotactl,
384 	kernfs_statfs,
385 	kernfs_sync,
386 	kernfs_vget,
387 	kernfs_fhtovp,
388 	kernfs_vptofh,
389 	kernfs_init,
390 	NULL,
391 	kernfs_done,
392 	kernfs_sysctl,
393 	NULL,				/* vfs_mountroot */
394 	kernfs_checkexp,
395 	kernfs_vnodeopv_descs,
396 };
397