xref: /netbsd-src/sys/miscfs/kernfs/kernfs_vfsops.c (revision 6ea46cb5e46c49111a6ecf3bcbe3c7e2730fe9f6)
1 /*	$NetBSD: kernfs_vfsops.c,v 1.19 1994/09/15 03:42:39 mycroft Exp $	*/
2 
3 /*
4  * Copyright (c) 1992, 1993
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	8.5 (Berkeley) 6/15/94
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 kernfs_init()
61 {
62 
63 }
64 
65 void
66 kernfs_get_rrootdev()
67 {
68 	static int tried = 0;
69 	int cmaj;
70 
71 	if (tried) {
72 		/* Already did it once. */
73 		return;
74 	}
75 	tried = 1;
76 
77 	if (rootdev == NODEV)
78 		return;
79 	for (cmaj = 0; cmaj < nchrdev; cmaj++) {
80 		rrootdev = makedev(cmaj, minor(rootdev));
81 		if (chrtoblk(rrootdev) == rootdev)
82 			return;
83 	}
84 	rrootdev = NODEV;
85 	printf("kernfs_get_rrootdev: no raw root device\n");
86 }
87 
88 /*
89  * Mount the Kernel params filesystem
90  */
91 kernfs_mount(mp, path, data, ndp, p)
92 	struct mount *mp;
93 	char *path;
94 	caddr_t data;
95 	struct nameidata *ndp;
96 	struct proc *p;
97 {
98 	int error = 0;
99 	u_int size;
100 	struct kernfs_mount *fmp;
101 	struct vnode *rvp;
102 
103 #ifdef KERNFS_DIAGNOSTIC
104 	printf("kernfs_mount(mp = %x)\n", mp);
105 #endif
106 
107 	/*
108 	 * Update is a no-op
109 	 */
110 	if (mp->mnt_flag & MNT_UPDATE)
111 		return (EOPNOTSUPP);
112 
113 	if (error = getnewvnode(VT_KERNFS, mp, kernfs_vnodeop_p, &rvp))
114 		return (error);
115 
116 	MALLOC(fmp, struct kernfs_mount *, sizeof(struct kernfs_mount),
117 	    M_MISCFSMNT, M_WAITOK);
118 	rvp->v_type = VDIR;
119 	rvp->v_flag |= VROOT;
120 #ifdef KERNFS_DIAGNOSTIC
121 	printf("kernfs_mount: root vp = %x\n", rvp);
122 #endif
123 	fmp->kf_root = rvp;
124 	mp->mnt_flag |= MNT_LOCAL;
125 	mp->mnt_data = (qaddr_t)fmp;
126 	getnewfsid(mp, makefstype(MOUNT_KERNFS));
127 
128 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
129 	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
130 	bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
131 	bcopy("kernfs", mp->mnt_stat.f_mntfromname, sizeof("kernfs"));
132 	(void)kernfs_statfs(mp, &mp->mnt_stat, p);
133 #ifdef KERNFS_DIAGNOSTIC
134 	printf("kernfs_mount: at %s\n", mp->mnt_stat.f_mntonname);
135 #endif
136 
137 	kernfs_get_rrootdev();
138 	return (0);
139 }
140 
141 kernfs_start(mp, flags, p)
142 	struct mount *mp;
143 	int flags;
144 	struct proc *p;
145 {
146 
147 	return (0);
148 }
149 
150 kernfs_unmount(mp, mntflags, p)
151 	struct mount *mp;
152 	int mntflags;
153 	struct proc *p;
154 {
155 	int error;
156 	int flags = 0;
157 	extern int doforce;
158 	struct vnode *rootvp = VFSTOKERNFS(mp)->kf_root;
159 
160 #ifdef KERNFS_DIAGNOSTIC
161 	printf("kernfs_unmount(mp = %x)\n", mp);
162 #endif
163 
164 	if (mntflags & MNT_FORCE) {
165 		/* kernfs can never be rootfs so don't check for it */
166 		if (!doforce)
167 			return (EINVAL);
168 		flags |= FORCECLOSE;
169 	}
170 
171 	/*
172 	 * Clear out buffer cache.  I don't think we
173 	 * ever get anything cached at this level at the
174 	 * moment, but who knows...
175 	 */
176 	if (rootvp->v_usecount > 1)
177 		return (EBUSY);
178 #ifdef KERNFS_DIAGNOSTIC
179 	printf("kernfs_unmount: calling vflush\n");
180 #endif
181 	if (error = vflush(mp, rootvp, flags))
182 		return (error);
183 
184 #ifdef KERNFS_DIAGNOSTIC
185 	vprint("kernfs root", rootvp);
186 #endif
187 	/*
188 	 * Clean out the old root vnode for reuse.
189 	 */
190 	vrele(rootvp);
191 	vgone(rootvp);
192 	/*
193 	 * Finally, throw away the kernfs_mount structure
194 	 */
195 	free(mp->mnt_data, M_MISCFSMNT);
196 	mp->mnt_data = 0;
197 	return (0);
198 }
199 
200 kernfs_root(mp, vpp)
201 	struct mount *mp;
202 	struct vnode **vpp;
203 {
204 	struct vnode *vp;
205 
206 #ifdef KERNFS_DIAGNOSTIC
207 	printf("kernfs_root(mp = %x)\n", mp);
208 #endif
209 
210 	/*
211 	 * Return locked reference to root.
212 	 */
213 	vp = VFSTOKERNFS(mp)->kf_root;
214 	VREF(vp);
215 	VOP_LOCK(vp);
216 	*vpp = vp;
217 	return (0);
218 }
219 
220 kernfs_quotactl(mp, cmd, uid, arg, p)
221 	struct mount *mp;
222 	int cmd;
223 	uid_t uid;
224 	caddr_t arg;
225 	struct proc *p;
226 {
227 
228 	return (EOPNOTSUPP);
229 }
230 
231 kernfs_statfs(mp, sbp, p)
232 	struct mount *mp;
233 	struct statfs *sbp;
234 	struct proc *p;
235 {
236 
237 #ifdef KERNFS_DIAGNOSTIC
238 	printf("kernfs_statfs(mp = %x)\n", mp);
239 #endif
240 
241 #ifdef COMPAT_09
242 	sbp->f_type = 7;
243 #else
244 	sbp->f_type = 0;
245 #endif
246 	sbp->f_bsize = DEV_BSIZE;
247 	sbp->f_iosize = DEV_BSIZE;
248 	sbp->f_blocks = 2;		/* 1K to keep df happy */
249 	sbp->f_bfree = 0;
250 	sbp->f_bavail = 0;
251 	sbp->f_files = 0;
252 	sbp->f_ffree = 0;
253 	if (sbp != &mp->mnt_stat) {
254 		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
255 		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
256 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
257 	}
258 	strncpy(&sbp->f_fstypename[0], mp->mnt_op->vfs_name, MFSNAMELEN);
259 	sbp->f_fstypename[MFSNAMELEN] = '\0';
260 	return (0);
261 }
262 
263 kernfs_sync(mp, waitfor)
264 	struct mount *mp;
265 	int waitfor;
266 {
267 
268 	return (0);
269 }
270 
271 /*
272  * Kernfs flat namespace lookup.
273  * Currently unsupported.
274  */
275 kernfs_vget(mp, ino, vpp)
276 	struct mount *mp;
277 	ino_t ino;
278 	struct vnode **vpp;
279 {
280 
281 	return (EOPNOTSUPP);
282 }
283 
284 
285 kernfs_fhtovp(mp, fhp, setgen, vpp)
286 	struct mount *mp;
287 	struct fid *fhp;
288 	int setgen;
289 	struct vnode **vpp;
290 {
291 
292 	return (EOPNOTSUPP);
293 }
294 
295 kernfs_vptofh(vp, fhp)
296 	struct vnode *vp;
297 	struct fid *fhp;
298 {
299 
300 	return (EOPNOTSUPP);
301 }
302 
303 struct vfsops kernfs_vfsops = {
304 	MOUNT_KERNFS,
305 	kernfs_mount,
306 	kernfs_start,
307 	kernfs_unmount,
308 	kernfs_root,
309 	kernfs_quotactl,
310 	kernfs_statfs,
311 	kernfs_sync,
312 	kernfs_vget,
313 	kernfs_fhtovp,
314 	kernfs_vptofh,
315 	kernfs_init,
316 };
317