xref: /freebsd/sys/fs/devfs/devfs_vfsops.c (revision 1a2cdef4962b47be5057809ce730a733b7f3c27c)
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 	struct devfs_mount *fmp;
71 	struct vnode *rvp;
72 
73 	error = 0;
74 	/*
75 	 * XXX: flag changes.
76 	 */
77 	if (mp->mnt_flag & MNT_UPDATE)
78 		return (EOPNOTSUPP);
79 
80 	MALLOC(fmp, struct devfs_mount *, sizeof(struct devfs_mount),
81 	    M_DEVFS, M_WAITOK | M_ZERO);
82 	lockinit(&fmp->dm_lock, PVFS, "devfs", 0, LK_NOPAUSE);
83 
84 	mp->mnt_flag |= MNT_LOCAL;
85 	mp->mnt_data = (qaddr_t) fmp;
86 	vfs_getnewfsid(mp);
87 
88 	fmp->dm_inode = DEVFSINOMOUNT;
89 
90 	fmp->dm_rootdir = devfs_vmkdir("(root)", 6, NULL);
91 	fmp->dm_rootdir->de_inode = 2;
92 	fmp->dm_basedir = fmp->dm_rootdir;
93 
94 	error = devfs_root(mp, &rvp);
95 	if (error) {
96 		lockdestroy(&fmp->dm_lock);
97 		FREE(fmp, M_DEVFS);
98 		return (error);
99 	}
100 	VOP_UNLOCK(rvp, 0, p);
101 
102 	bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
103 	bcopy("devfs", mp->mnt_stat.f_mntfromname, sizeof("devfs"));
104 	(void)devfs_statfs(mp, &mp->mnt_stat, p);
105 
106 	return (0);
107 }
108 
109 static int
110 devfs_unmount(mp, mntflags, p)
111 	struct mount *mp;
112 	int mntflags;
113 	struct proc *p;
114 {
115 	int error;
116 	int flags = 0;
117 	struct vnode *rootvp;
118 	struct devfs_mount *fmp;
119 
120 	error = devfs_root(mp, &rootvp);
121 	if (error)
122 		return (error);
123 	fmp = VFSTODEVFS(mp);
124 	if (mntflags & MNT_FORCE)
125 		flags |= FORCECLOSE;
126 	if (rootvp->v_usecount > 2) {
127 		vrele(rootvp);
128 		return (EBUSY);
129 	}
130 	error = vflush(mp, rootvp, flags);
131 	if (error)
132 		return (error);
133 	devfs_purge(fmp->dm_rootdir);
134 	vput(rootvp);
135 	vrele(rootvp);
136 	vgone(rootvp);
137 	mp->mnt_data = 0;
138 	lockdestroy(&fmp->dm_lock);
139 	free(fmp, M_DEVFS);
140 	return 0;
141 }
142 
143 /* Return locked reference to root.  */
144 
145 static int
146 devfs_root(mp, vpp)
147 	struct mount *mp;
148 	struct vnode **vpp;
149 {
150 	int error;
151 	struct proc *p;
152 	struct vnode *vp;
153 	struct devfs_mount *dmp;
154 
155 	p = curproc;					/* XXX */
156 	dmp = VFSTODEVFS(mp);
157 	error = devfs_allocv(dmp->dm_rootdir, mp, &vp, p);
158 	if (error)
159 		return (error);
160 	vp->v_flag |= VROOT;
161 	*vpp = vp;
162 	return (0);
163 }
164 
165 static int
166 devfs_statfs(mp, sbp, p)
167 	struct mount *mp;
168 	struct statfs *sbp;
169 	struct proc *p;
170 {
171 
172 	sbp->f_flags = 0;
173 	sbp->f_bsize = DEV_BSIZE;
174 	sbp->f_iosize = DEV_BSIZE;
175 	sbp->f_blocks = 2;		/* 1K to keep df happy */
176 	sbp->f_bfree = 0;
177 	sbp->f_bavail = 0;
178 	sbp->f_files = 0;
179 	sbp->f_ffree = 0;
180 	if (sbp != &mp->mnt_stat) {
181 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
182 		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
183 		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
184 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
185 	}
186 	return (0);
187 }
188 
189 static struct vfsops devfs_vfsops = {
190 	devfs_mount,
191 	vfs_stdstart,
192 	devfs_unmount,
193 	devfs_root,
194 	vfs_stdquotactl,
195 	devfs_statfs,
196 	vfs_stdsync,
197 	vfs_stdvget,
198 	vfs_stdfhtovp,
199 	vfs_stdcheckexp,
200 	vfs_stdvptofh,
201 	vfs_stdinit,
202 	vfs_stduninit,
203 	vfs_stdextattrctl,
204 };
205 
206 VFS_SET(devfs_vfsops, devfs, VFCF_SYNTHETIC);
207