xref: /freebsd/sys/fs/devfs/devfs_vfsops.c (revision 35ccfc58d8065d58df2469c13fce9d3a60d53845)
1 /*
2  * Copyright (c) 1992, 1993, 1995
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 2000
5  *	Poul-Henning Kamp.  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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)kernfs_vfsops.c	8.10 (Berkeley) 5/14/95
32  * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vfsops.c 1.36
33  *
34  * $FreeBSD$
35  */
36 
37 #include "opt_devfs.h"
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
42 #include <sys/vnode.h>
43 #include <sys/mount.h>
44 #include <sys/malloc.h>
45 
46 #include <fs/devfs/devfs.h>
47 
48 MALLOC_DEFINE(M_DEVFS, "DEVFS", "DEVFS data");
49 
50 static int	devfs_mount __P((struct mount *mp, char *path, caddr_t data,
51 				  struct nameidata *ndp, struct proc *p));
52 static int	devfs_unmount __P((struct mount *mp, int mntflags,
53 				  struct proc *p));
54 static int	devfs_root __P((struct mount *mp, struct vnode **vpp));
55 static int	devfs_statfs __P((struct mount *mp, struct statfs *sbp,
56 				   struct proc *p));
57 
58 /*
59  * Mount the filesystem
60  */
61 static int
62 devfs_mount(mp, path, data, ndp, p)
63 	struct mount *mp;
64 	char *path;
65 	caddr_t data;
66 	struct nameidata *ndp;
67 	struct proc *p;
68 {
69 	int error;
70 	size_t size;
71 	struct devfs_mount *fmp;
72 	struct vnode *rvp;
73 
74 	error = 0;
75 	/*
76 	 * XXX: flag changes.
77 	 */
78 	if (mp->mnt_flag & MNT_UPDATE)
79 		return (EOPNOTSUPP);
80 
81 	MALLOC(fmp, struct devfs_mount *, sizeof(struct devfs_mount),
82 	    M_DEVFS, M_WAITOK);
83 	bzero(fmp, sizeof(*fmp));
84 	lockinit(&fmp->dm_lock, PVFS, "devfs", 0, LK_NOPAUSE);
85 
86 	mp->mnt_flag |= MNT_LOCAL;
87 	mp->mnt_data = (qaddr_t) fmp;
88 	vfs_getnewfsid(mp);
89 
90 	fmp->dm_inode = DEVFSINOMOUNT;
91 
92 	fmp->dm_rootdir = devfs_vmkdir("(root)", 6, NULL);
93 	fmp->dm_rootdir->de_inode = 2;
94 	fmp->dm_basedir = fmp->dm_rootdir;
95 
96 	error = devfs_root(mp, &rvp);
97 	if (error) {
98 		lockdestroy(&fmp->dm_lock);
99 		FREE(fmp, M_DEVFS);
100 		return (error);
101 	}
102 	VOP_UNLOCK(rvp, 0, p);
103 
104 	if (path != NULL) {
105 		(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
106 	} else {
107 		strcpy(mp->mnt_stat.f_mntonname, "/");
108 		size = 1;
109 	}
110 	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
111 	bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
112 	bcopy("devfs", mp->mnt_stat.f_mntfromname, sizeof("devfs"));
113 	(void)devfs_statfs(mp, &mp->mnt_stat, p);
114 
115 	return (0);
116 }
117 
118 static int
119 devfs_unmount(mp, mntflags, p)
120 	struct mount *mp;
121 	int mntflags;
122 	struct proc *p;
123 {
124 	int error;
125 	int flags = 0;
126 	struct vnode *rootvp;
127 	struct devfs_mount *fmp;
128 
129 	error = devfs_root(mp, &rootvp);
130 	if (error)
131 		return (error);
132 	fmp = VFSTODEVFS(mp);
133 	if (mntflags & MNT_FORCE)
134 		flags |= FORCECLOSE;
135 	if (rootvp->v_usecount > 2) {
136 		vrele(rootvp);
137 		return (EBUSY);
138 	}
139 	error = vflush(mp, rootvp, flags);
140 	if (error)
141 		return (error);
142 	devfs_purge(fmp->dm_rootdir);
143 	vput(rootvp);
144 	vrele(rootvp);
145 	vgone(rootvp);
146 	mp->mnt_data = 0;
147 	lockdestroy(&fmp->dm_lock);
148 	free(fmp, M_DEVFS);
149 	return 0;
150 }
151 
152 /* Return locked reference to root.  */
153 
154 static int
155 devfs_root(mp, vpp)
156 	struct mount *mp;
157 	struct vnode **vpp;
158 {
159 	int error;
160 	struct proc *p;
161 	struct vnode *vp;
162 	struct devfs_mount *dmp;
163 
164 	p = curproc;					/* XXX */
165 	dmp = VFSTODEVFS(mp);
166 	error = devfs_allocv(dmp->dm_rootdir, mp, &vp, p);
167 	if (error)
168 		return (error);
169 	vp->v_flag |= VROOT;
170 	*vpp = vp;
171 	return (0);
172 }
173 
174 static int
175 devfs_statfs(mp, sbp, p)
176 	struct mount *mp;
177 	struct statfs *sbp;
178 	struct proc *p;
179 {
180 
181 	sbp->f_flags = 0;
182 	sbp->f_bsize = DEV_BSIZE;
183 	sbp->f_iosize = DEV_BSIZE;
184 	sbp->f_blocks = 2;		/* 1K to keep df happy */
185 	sbp->f_bfree = 0;
186 	sbp->f_bavail = 0;
187 	sbp->f_files = 0;
188 	sbp->f_ffree = 0;
189 	if (sbp != &mp->mnt_stat) {
190 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
191 		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
192 		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
193 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
194 	}
195 	return (0);
196 }
197 
198 static struct vfsops devfs_vfsops = {
199 	devfs_mount,
200 	vfs_stdstart,
201 	devfs_unmount,
202 	devfs_root,
203 	vfs_stdquotactl,
204 	devfs_statfs,
205 	vfs_stdsync,
206 	vfs_stdvget,
207 	vfs_stdfhtovp,
208 	vfs_stdcheckexp,
209 	vfs_stdvptofh,
210 	vfs_stdinit,
211 	vfs_stduninit,
212 	vfs_stdextattrctl,
213 };
214 
215 VFS_SET(devfs_vfsops, devfs, VFCF_SYNTHETIC);
216