xref: /netbsd-src/sys/miscfs/kernfs/kernfs_vfsops.c (revision 267197ec1eebfcb9810ea27a89625b6ddf68e3e7)
1 /*	$NetBSD: kernfs_vfsops.c,v 1.83 2008/01/28 14:31:18 dholland 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. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)kernfs_vfsops.c	8.10 (Berkeley) 5/14/95
35  */
36 
37 /*
38  * Kernel params Filesystem
39  */
40 
41 #include <sys/cdefs.h>
42 __KERNEL_RCSID(0, "$NetBSD: kernfs_vfsops.c,v 1.83 2008/01/28 14:31:18 dholland Exp $");
43 
44 #ifdef _KERNEL_OPT
45 #include "opt_compat_netbsd.h"
46 #endif
47 
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/sysctl.h>
51 #include <sys/conf.h>
52 #include <sys/proc.h>
53 #include <sys/vnode.h>
54 #include <sys/mount.h>
55 #include <sys/namei.h>
56 #include <sys/dirent.h>
57 #include <sys/malloc.h>
58 #include <sys/syslog.h>
59 #include <sys/kauth.h>
60 
61 #include <miscfs/genfs/genfs.h>
62 #include <miscfs/specfs/specdev.h>
63 #include <miscfs/kernfs/kernfs.h>
64 
65 MALLOC_JUSTDEFINE(M_KERNFSMNT, "kernfs mount", "kernfs mount structures");
66 
67 dev_t rrootdev = NODEV;
68 
69 VFS_PROTOS(kernfs);
70 
71 void	kernfs_get_rrootdev(void);
72 
73 void
74 kernfs_init()
75 {
76 
77 	malloc_type_attach(M_KERNFSMNT);
78 	kernfs_hashinit();
79 }
80 
81 void
82 kernfs_reinit()
83 {
84 	kernfs_hashreinit();
85 }
86 
87 void
88 kernfs_done()
89 {
90 
91 	kernfs_hashdone();
92 	malloc_type_detach(M_KERNFSMNT);
93 }
94 
95 void
96 kernfs_get_rrootdev()
97 {
98 	static int tried = 0;
99 
100 	if (tried) {
101 		/* Already did it once. */
102 		return;
103 	}
104 	tried = 1;
105 
106 	if (rootdev == NODEV)
107 		return;
108 	rrootdev = devsw_blk2chr(rootdev);
109 	if (rrootdev != NODEV)
110 		return;
111 	rrootdev = NODEV;
112 	printf("kernfs_get_rrootdev: no raw root device\n");
113 }
114 
115 /*
116  * Mount the Kernel params filesystem
117  */
118 int
119 kernfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
120 {
121 	struct lwp *l = curlwp;
122 	int error = 0;
123 	struct kernfs_mount *fmp;
124 
125 	if (UIO_MX & (UIO_MX - 1)) {
126 		log(LOG_ERR, "kernfs: invalid directory entry size");
127 		return (EINVAL);
128 	}
129 
130 	if (mp->mnt_flag & MNT_GETARGS) {
131 		*data_len = 0;
132 		return 0;
133 	}
134 	/*
135 	 * Update is a no-op
136 	 */
137 	if (mp->mnt_flag & MNT_UPDATE)
138 		return (EOPNOTSUPP);
139 
140 	MALLOC(fmp, struct kernfs_mount *, sizeof(struct kernfs_mount),
141 	    M_KERNFSMNT, M_WAITOK);
142 	memset(fmp, 0, sizeof(*fmp));
143 	TAILQ_INIT(&fmp->nodelist);
144 
145 	mp->mnt_stat.f_namemax = MAXNAMLEN;
146 	mp->mnt_flag |= MNT_LOCAL;
147 	mp->mnt_data = fmp;
148 	vfs_getnewfsid(mp);
149 
150 	if ((error = set_statvfs_info(path, UIO_USERSPACE, "kernfs",
151 	    UIO_SYSSPACE, mp->mnt_op->vfs_name, mp, l)) != 0) {
152 		free(fmp, M_KERNFSMNT);
153 		return error;
154 	}
155 
156 	kernfs_get_rrootdev();
157 	return 0;
158 }
159 
160 int
161 kernfs_start(struct mount *mp, int flags)
162 {
163 
164 	return (0);
165 }
166 
167 int
168 kernfs_unmount(struct mount *mp, int mntflags)
169 {
170 	int error;
171 	int flags = 0;
172 
173 	if (mntflags & MNT_FORCE)
174 		flags |= FORCECLOSE;
175 
176 	if ((error = vflush(mp, 0, flags)) != 0)
177 		return (error);
178 
179 	/*
180 	 * Finally, throw away the kernfs_mount structure
181 	 */
182 	free(mp->mnt_data, M_KERNFSMNT);
183 	mp->mnt_data = NULL;
184 	return (0);
185 }
186 
187 int
188 kernfs_root(mp, vpp)
189 	struct mount *mp;
190 	struct vnode **vpp;
191 {
192 
193 	/* setup "." */
194 	return (kernfs_allocvp(mp, vpp, KFSkern, &kern_targets[0], 0));
195 }
196 
197 int
198 kernfs_statvfs(struct mount *mp, struct statvfs *sbp)
199 {
200 
201 	sbp->f_bsize = DEV_BSIZE;
202 	sbp->f_frsize = DEV_BSIZE;
203 	sbp->f_iosize = DEV_BSIZE;
204 	sbp->f_blocks = 2;		/* 1K to keep df happy */
205 	sbp->f_bfree = 0;
206 	sbp->f_bavail = 0;
207 	sbp->f_bresvd = 0;
208 	sbp->f_files = 1024;	/* XXX lie */
209 	sbp->f_ffree = 128;	/* XXX lie */
210 	sbp->f_favail = 128;	/* XXX lie */
211 	sbp->f_fresvd = 0;
212 	copy_statvfs_info(sbp, mp);
213 	return (0);
214 }
215 
216 /*ARGSUSED*/
217 int
218 kernfs_sync(struct mount *mp, int waitfor,
219     kauth_cred_t uc)
220 {
221 
222 	return (0);
223 }
224 
225 /*
226  * Kernfs flat namespace lookup.
227  * Currently unsupported.
228  */
229 int
230 kernfs_vget(struct mount *mp, ino_t ino,
231     struct vnode **vpp)
232 {
233 
234 	return (EOPNOTSUPP);
235 }
236 
237 SYSCTL_SETUP(sysctl_vfs_kernfs_setup, "sysctl vfs.kern subtree setup")
238 {
239 
240 	sysctl_createv(clog, 0, NULL, NULL,
241 		       CTLFLAG_PERMANENT,
242 		       CTLTYPE_NODE, "vfs", NULL,
243 		       NULL, 0, NULL, 0,
244 		       CTL_VFS, CTL_EOL);
245 	sysctl_createv(clog, 0, NULL, NULL,
246 		       CTLFLAG_PERMANENT,
247 		       CTLTYPE_NODE, "kernfs",
248 		       SYSCTL_DESCR("/kern file system"),
249 		       NULL, 0, NULL, 0,
250 		       CTL_VFS, 11, CTL_EOL);
251 	/*
252 	 * XXX the "11" above could be dynamic, thereby eliminating one
253 	 * more instance of the "number to vfs" mapping problem, but
254 	 * "11" is the order as taken from sys/mount.h
255 	 */
256 }
257 
258 extern const struct vnodeopv_desc kernfs_vnodeop_opv_desc;
259 
260 const struct vnodeopv_desc * const kernfs_vnodeopv_descs[] = {
261 	&kernfs_vnodeop_opv_desc,
262 	NULL,
263 };
264 
265 struct vfsops kernfs_vfsops = {
266 	MOUNT_KERNFS,
267 	0,
268 	kernfs_mount,
269 	kernfs_start,
270 	kernfs_unmount,
271 	kernfs_root,
272 	(void *)eopnotsupp,		/* vfs_quotactl */
273 	kernfs_statvfs,
274 	kernfs_sync,
275 	kernfs_vget,
276 	(void *)eopnotsupp,		/* vfs_fhtovp */
277 	(void *)eopnotsupp,		/* vfs_vptofh */
278 	kernfs_init,
279 	kernfs_reinit,
280 	kernfs_done,
281 	NULL,				/* vfs_mountroot */
282 	(int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp,
283 	vfs_stdextattrctl,
284 	(void *)eopnotsupp,		/* vfs_suspendctl */
285 	genfs_renamelock_enter,
286 	genfs_renamelock_exit,
287 	kernfs_vnodeopv_descs,
288 	0,
289 	{ NULL, NULL },
290 };
291 VFS_ATTACH(kernfs_vfsops);
292