xref: /netbsd-src/sys/miscfs/kernfs/kernfs_vfsops.c (revision 08c81a9c2dc8c7300e893321eb65c0925d60871c)
1 /*	$NetBSD: kernfs_vfsops.c,v 1.45 2002/09/06 13:18:43 gehenna 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 1.45 2002/09/06 13:18:43 gehenna 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 	/*
142 	 * Update is a no-op
143 	 */
144 	if (mp->mnt_flag & MNT_UPDATE)
145 		return (EOPNOTSUPP);
146 
147 	error = getnewvnode(VT_KERNFS, mp, kernfs_vnodeop_p, &rvp);
148 	if (error)
149 		return (error);
150 
151 	MALLOC(fmp, struct kernfs_mount *, sizeof(struct kernfs_mount),
152 	    M_MISCFSMNT, M_WAITOK);
153 	rvp->v_type = VDIR;
154 	rvp->v_flag |= VROOT;
155 #ifdef KERNFS_DIAGNOSTIC
156 	printf("kernfs_mount: root vp = %p\n", rvp);
157 #endif
158 	fmp->kf_root = rvp;
159 	mp->mnt_flag |= MNT_LOCAL;
160 	mp->mnt_data = fmp;
161 	vfs_getnewfsid(mp);
162 
163 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
164 	memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size);
165 	memset(mp->mnt_stat.f_mntfromname, 0, MNAMELEN);
166 	memcpy(mp->mnt_stat.f_mntfromname, "kernfs", sizeof("kernfs"));
167 #ifdef KERNFS_DIAGNOSTIC
168 	printf("kernfs_mount: at %s\n", mp->mnt_stat.f_mntonname);
169 #endif
170 
171 	kernfs_get_rrootdev();
172 	return (0);
173 }
174 
175 int
176 kernfs_start(mp, flags, p)
177 	struct mount *mp;
178 	int flags;
179 	struct proc *p;
180 {
181 
182 	return (0);
183 }
184 
185 int
186 kernfs_unmount(mp, mntflags, p)
187 	struct mount *mp;
188 	int mntflags;
189 	struct proc *p;
190 {
191 	int error;
192 	int flags = 0;
193 	struct vnode *rootvp = VFSTOKERNFS(mp)->kf_root;
194 
195 #ifdef KERNFS_DIAGNOSTIC
196 	printf("kernfs_unmount(mp = %p)\n", mp);
197 #endif
198 
199 	 if (mntflags & MNT_FORCE)
200 		flags |= FORCECLOSE;
201 
202 	/*
203 	 * Clear out buffer cache.  I don't think we
204 	 * ever get anything cached at this level at the
205 	 * moment, but who knows...
206 	 */
207 	if (rootvp->v_usecount > 1)
208 		return (EBUSY);
209 #ifdef KERNFS_DIAGNOSTIC
210 	printf("kernfs_unmount: calling vflush\n");
211 #endif
212 	if ((error = vflush(mp, rootvp, flags)) != 0)
213 		return (error);
214 
215 #ifdef KERNFS_DIAGNOSTIC
216 	vprint("kernfs root", rootvp);
217 #endif
218 	/*
219 	 * Clean out the old root vnode for reuse.
220 	 */
221 	vrele(rootvp);
222 	vgone(rootvp);
223 	/*
224 	 * Finally, throw away the kernfs_mount structure
225 	 */
226 	free(mp->mnt_data, M_MISCFSMNT);
227 	mp->mnt_data = 0;
228 	return (0);
229 }
230 
231 int
232 kernfs_root(mp, vpp)
233 	struct mount *mp;
234 	struct vnode **vpp;
235 {
236 	struct vnode *vp;
237 
238 #ifdef KERNFS_DIAGNOSTIC
239 	printf("kernfs_root(mp = %p)\n", mp);
240 #endif
241 
242 	/*
243 	 * Return locked reference to root.
244 	 */
245 	vp = VFSTOKERNFS(mp)->kf_root;
246 	VREF(vp);
247 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
248 	*vpp = vp;
249 	return (0);
250 }
251 
252 int
253 kernfs_quotactl(mp, cmd, uid, arg, p)
254 	struct mount *mp;
255 	int cmd;
256 	uid_t uid;
257 	caddr_t arg;
258 	struct proc *p;
259 {
260 
261 	return (EOPNOTSUPP);
262 }
263 
264 int
265 kernfs_statfs(mp, sbp, p)
266 	struct mount *mp;
267 	struct statfs *sbp;
268 	struct proc *p;
269 {
270 
271 #ifdef KERNFS_DIAGNOSTIC
272 	printf("kernfs_statfs(mp = %p)\n", mp);
273 #endif
274 
275 	sbp->f_bsize = DEV_BSIZE;
276 	sbp->f_iosize = DEV_BSIZE;
277 	sbp->f_blocks = 2;		/* 1K to keep df happy */
278 	sbp->f_bfree = 0;
279 	sbp->f_bavail = 0;
280 	sbp->f_files = 0;
281 	sbp->f_ffree = 0;
282 #ifdef COMPAT_09
283 	sbp->f_type = 7;
284 #else
285 	sbp->f_type = 0;
286 #endif
287 	if (sbp != &mp->mnt_stat) {
288 		memcpy(&sbp->f_fsid, &mp->mnt_stat.f_fsid, sizeof(sbp->f_fsid));
289 		memcpy(sbp->f_mntonname, mp->mnt_stat.f_mntonname, MNAMELEN);
290 		memcpy(sbp->f_mntfromname, mp->mnt_stat.f_mntfromname, MNAMELEN);
291 	}
292 	strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, MFSNAMELEN);
293 	return (0);
294 }
295 
296 /*ARGSUSED*/
297 int
298 kernfs_sync(mp, waitfor, uc, p)
299 	struct mount *mp;
300 	int waitfor;
301 	struct ucred *uc;
302 	struct proc *p;
303 {
304 
305 	return (0);
306 }
307 
308 /*
309  * Kernfs flat namespace lookup.
310  * Currently unsupported.
311  */
312 int
313 kernfs_vget(mp, ino, vpp)
314 	struct mount *mp;
315 	ino_t ino;
316 	struct vnode **vpp;
317 {
318 
319 	return (EOPNOTSUPP);
320 }
321 
322 /*ARGSUSED*/
323 int
324 kernfs_fhtovp(mp, fhp, vpp)
325 	struct mount *mp;
326 	struct fid *fhp;
327 	struct vnode **vpp;
328 {
329 
330 	return (EOPNOTSUPP);
331 }
332 
333 /*ARGSUSED*/
334 int
335 kernfs_checkexp(mp, mb, what, anon)
336 	struct mount *mp;
337 	struct mbuf *mb;
338 	int *what;
339 	struct ucred **anon;
340 {
341 
342 	return (EOPNOTSUPP);
343 }
344 
345 /*ARGSUSED*/
346 int
347 kernfs_vptofh(vp, fhp)
348 	struct vnode *vp;
349 	struct fid *fhp;
350 {
351 
352 	return (EOPNOTSUPP);
353 }
354 
355 int
356 kernfs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
357 	int *name;
358 	u_int namelen;
359 	void *oldp;
360 	size_t *oldlenp;
361 	void *newp;
362 	size_t newlen;
363 	struct proc *p;
364 {
365 	return (EOPNOTSUPP);
366 }
367 
368 extern const struct vnodeopv_desc kernfs_vnodeop_opv_desc;
369 
370 const struct vnodeopv_desc * const kernfs_vnodeopv_descs[] = {
371 	&kernfs_vnodeop_opv_desc,
372 	NULL,
373 };
374 
375 struct vfsops kernfs_vfsops = {
376 	MOUNT_KERNFS,
377 	kernfs_mount,
378 	kernfs_start,
379 	kernfs_unmount,
380 	kernfs_root,
381 	kernfs_quotactl,
382 	kernfs_statfs,
383 	kernfs_sync,
384 	kernfs_vget,
385 	kernfs_fhtovp,
386 	kernfs_vptofh,
387 	kernfs_init,
388 	NULL,
389 	kernfs_done,
390 	kernfs_sysctl,
391 	NULL,				/* vfs_mountroot */
392 	kernfs_checkexp,
393 	kernfs_vnodeopv_descs,
394 };
395