xref: /netbsd-src/sys/miscfs/kernfs/kernfs_vfsops.c (revision 7c7c171d130af9949261bc7dce2150a03c3d239c)
1 /*	$NetBSD: kernfs_vfsops.c,v 1.32 1998/03/01 02:21:04 fvdl 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/param.h>
46 #include <sys/systm.h>
47 #include <sys/conf.h>
48 #include <sys/types.h>
49 #include <sys/proc.h>
50 #include <sys/vnode.h>
51 #include <sys/mount.h>
52 #include <sys/namei.h>
53 #include <sys/malloc.h>
54 
55 #include <miscfs/specfs/specdev.h>
56 #include <miscfs/kernfs/kernfs.h>
57 
58 dev_t rrootdev = NODEV;
59 
60 void	kernfs_init __P((void));
61 void	kernfs_get_rrootdev __P((void));
62 int	kernfs_mount __P((struct mount *, const char *, void *,
63 	    struct nameidata *, struct proc *));
64 int	kernfs_start __P((struct mount *, int, struct proc *));
65 int	kernfs_unmount __P((struct mount *, int, struct proc *));
66 int	kernfs_root __P((struct mount *, struct vnode **));
67 int	kernfs_statfs __P((struct mount *, struct statfs *, struct proc *));
68 int	kernfs_quotactl __P((struct mount *, int, uid_t, caddr_t,
69 			     struct proc *));
70 int	kernfs_sync __P((struct mount *, int, struct ucred *, struct proc *));
71 int	kernfs_vget __P((struct mount *, ino_t, struct vnode **));
72 int	kernfs_fhtovp __P((struct mount *, struct fid *, struct mbuf *,
73 			   struct vnode **, int *, struct ucred **));
74 int	kernfs_vptofh __P((struct vnode *, struct fid *));
75 int	kernfs_sysctl __P((int *, u_int, void *, size_t *, void *, size_t,
76 			   struct proc *));
77 
78 void
79 kernfs_init()
80 {
81 }
82 
83 void
84 kernfs_get_rrootdev()
85 {
86 	static int tried = 0;
87 	int cmaj;
88 
89 	if (tried) {
90 		/* Already did it once. */
91 		return;
92 	}
93 	tried = 1;
94 
95 	if (rootdev == NODEV)
96 		return;
97 	for (cmaj = 0; cmaj < nchrdev; cmaj++) {
98 		rrootdev = makedev(cmaj, minor(rootdev));
99 		if (chrtoblk(rrootdev) == rootdev)
100 			return;
101 	}
102 	rrootdev = NODEV;
103 	printf("kernfs_get_rrootdev: no raw root device\n");
104 }
105 
106 /*
107  * Mount the Kernel params filesystem
108  */
109 int
110 kernfs_mount(mp, path, data, ndp, p)
111 	struct mount *mp;
112 	const char *path;
113 	void *data;
114 	struct nameidata *ndp;
115 	struct proc *p;
116 {
117 	int error = 0;
118 	size_t size;
119 	struct kernfs_mount *fmp;
120 	struct vnode *rvp;
121 
122 #ifdef KERNFS_DIAGNOSTIC
123 	printf("kernfs_mount(mp = %p)\n", mp);
124 #endif
125 
126 	/*
127 	 * Update is a no-op
128 	 */
129 	if (mp->mnt_flag & MNT_UPDATE)
130 		return (EOPNOTSUPP);
131 
132 	error = getnewvnode(VT_KERNFS, mp, kernfs_vnodeop_p, &rvp);
133 	if (error)
134 		return (error);
135 
136 	MALLOC(fmp, struct kernfs_mount *, sizeof(struct kernfs_mount),
137 	    M_MISCFSMNT, M_WAITOK);
138 	rvp->v_type = VDIR;
139 	rvp->v_flag |= VROOT;
140 #ifdef KERNFS_DIAGNOSTIC
141 	printf("kernfs_mount: root vp = %p\n", rvp);
142 #endif
143 	fmp->kf_root = rvp;
144 	mp->mnt_flag |= MNT_LOCAL;
145 	mp->mnt_data = (qaddr_t)fmp;
146 	vfs_getnewfsid(mp, MOUNT_KERNFS);
147 
148 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
149 	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
150 	bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
151 	bcopy("kernfs", mp->mnt_stat.f_mntfromname, sizeof("kernfs"));
152 #ifdef KERNFS_DIAGNOSTIC
153 	printf("kernfs_mount: at %s\n", mp->mnt_stat.f_mntonname);
154 #endif
155 
156 	kernfs_get_rrootdev();
157 	return (0);
158 }
159 
160 int
161 kernfs_start(mp, flags, p)
162 	struct mount *mp;
163 	int flags;
164 	struct proc *p;
165 {
166 
167 	return (0);
168 }
169 
170 int
171 kernfs_unmount(mp, mntflags, p)
172 	struct mount *mp;
173 	int mntflags;
174 	struct proc *p;
175 {
176 	int error;
177 	int flags = 0;
178 	struct vnode *rootvp = VFSTOKERNFS(mp)->kf_root;
179 
180 #ifdef KERNFS_DIAGNOSTIC
181 	printf("kernfs_unmount(mp = %p)\n", mp);
182 #endif
183 
184 	 if (mntflags & MNT_FORCE)
185 		flags |= FORCECLOSE;
186 
187 	/*
188 	 * Clear out buffer cache.  I don't think we
189 	 * ever get anything cached at this level at the
190 	 * moment, but who knows...
191 	 */
192 	if (rootvp->v_usecount > 1)
193 		return (EBUSY);
194 #ifdef KERNFS_DIAGNOSTIC
195 	printf("kernfs_unmount: calling vflush\n");
196 #endif
197 	if ((error = vflush(mp, rootvp, flags)) != 0)
198 		return (error);
199 
200 #ifdef KERNFS_DIAGNOSTIC
201 	vprint("kernfs root", rootvp);
202 #endif
203 	/*
204 	 * Clean out the old root vnode for reuse.
205 	 */
206 	vrele(rootvp);
207 	vgone(rootvp);
208 	/*
209 	 * Finally, throw away the kernfs_mount structure
210 	 */
211 	free(mp->mnt_data, M_MISCFSMNT);
212 	mp->mnt_data = 0;
213 	return (0);
214 }
215 
216 int
217 kernfs_root(mp, vpp)
218 	struct mount *mp;
219 	struct vnode **vpp;
220 {
221 	struct vnode *vp;
222 
223 #ifdef KERNFS_DIAGNOSTIC
224 	printf("kernfs_root(mp = %p)\n", mp);
225 #endif
226 
227 	/*
228 	 * Return locked reference to root.
229 	 */
230 	vp = VFSTOKERNFS(mp)->kf_root;
231 	VREF(vp);
232 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
233 	*vpp = vp;
234 	return (0);
235 }
236 
237 int
238 kernfs_quotactl(mp, cmd, uid, arg, p)
239 	struct mount *mp;
240 	int cmd;
241 	uid_t uid;
242 	caddr_t arg;
243 	struct proc *p;
244 {
245 
246 	return (EOPNOTSUPP);
247 }
248 
249 int
250 kernfs_statfs(mp, sbp, p)
251 	struct mount *mp;
252 	struct statfs *sbp;
253 	struct proc *p;
254 {
255 
256 #ifdef KERNFS_DIAGNOSTIC
257 	printf("kernfs_statfs(mp = %p)\n", mp);
258 #endif
259 
260 	sbp->f_bsize = DEV_BSIZE;
261 	sbp->f_iosize = DEV_BSIZE;
262 	sbp->f_blocks = 2;		/* 1K to keep df happy */
263 	sbp->f_bfree = 0;
264 	sbp->f_bavail = 0;
265 	sbp->f_files = 0;
266 	sbp->f_ffree = 0;
267 #ifdef COMPAT_09
268 	sbp->f_type = 7;
269 #else
270 	sbp->f_type = 0;
271 #endif
272 	if (sbp != &mp->mnt_stat) {
273 		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
274 		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
275 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
276 	}
277 	strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, MFSNAMELEN);
278 	return (0);
279 }
280 
281 /*ARGSUSED*/
282 int
283 kernfs_sync(mp, waitfor, uc, p)
284 	struct mount *mp;
285 	int waitfor;
286 	struct ucred *uc;
287 	struct proc *p;
288 {
289 
290 	return (0);
291 }
292 
293 /*
294  * Kernfs flat namespace lookup.
295  * Currently unsupported.
296  */
297 int
298 kernfs_vget(mp, ino, vpp)
299 	struct mount *mp;
300 	ino_t ino;
301 	struct vnode **vpp;
302 {
303 
304 	return (EOPNOTSUPP);
305 }
306 
307 /*ARGSUSED*/
308 int
309 kernfs_fhtovp(mp, fhp, mb, vpp, what, anon)
310 	struct mount *mp;
311 	struct fid *fhp;
312 	struct mbuf *mb;
313 	struct vnode **vpp;
314 	int *what;
315 	struct ucred **anon;
316 {
317 
318 	return (EOPNOTSUPP);
319 }
320 
321 /*ARGSUSED*/
322 int
323 kernfs_vptofh(vp, fhp)
324 	struct vnode *vp;
325 	struct fid *fhp;
326 {
327 
328 	return (EOPNOTSUPP);
329 }
330 
331 int
332 kernfs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
333 	int *name;
334 	u_int namelen;
335 	void *oldp;
336 	size_t *oldlenp;
337 	void *newp;
338 	size_t newlen;
339 	struct proc *p;
340 {
341 	return (EOPNOTSUPP);
342 }
343 
344 extern struct vnodeopv_desc kernfs_vnodeop_opv_desc;
345 
346 struct vnodeopv_desc *kernfs_vnodeopv_descs[] = {
347 	&kernfs_vnodeop_opv_desc,
348 	NULL,
349 };
350 
351 struct vfsops kernfs_vfsops = {
352 	MOUNT_KERNFS,
353 	kernfs_mount,
354 	kernfs_start,
355 	kernfs_unmount,
356 	kernfs_root,
357 	kernfs_quotactl,
358 	kernfs_statfs,
359 	kernfs_sync,
360 	kernfs_vget,
361 	kernfs_fhtovp,
362 	kernfs_vptofh,
363 	kernfs_init,
364 	kernfs_sysctl,
365 	NULL,				/* vfs_mountroot */
366 	kernfs_vnodeopv_descs,
367 };
368