xref: /freebsd/sys/fs/devfs/devfs_vfsops.c (revision 6af83ee0d2941d18880b6aaa2b4facd1d30c6106)
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 #include "opt_mac.h"
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/kernel.h>
43 #include <sys/lock.h>
44 #include <sys/mac.h>
45 #include <sys/malloc.h>
46 #include <sys/mount.h>
47 #include <sys/proc.h>
48 #include <sys/vnode.h>
49 
50 #include <fs/devfs/devfs.h>
51 
52 MALLOC_DEFINE(M_DEVFS, "DEVFS", "DEVFS data");
53 
54 static vfs_mount_t	devfs_mount;
55 static vfs_unmount_t	devfs_unmount;
56 static vfs_root_t	devfs_root;
57 static vfs_statfs_t	devfs_statfs;
58 
59 /*
60  * Mount the filesystem
61  */
62 static int
63 devfs_mount(struct mount *mp, struct thread *td)
64 {
65 	int error;
66 	struct devfs_mount *fmp;
67 	struct vnode *rvp;
68 
69 	error = 0;
70 
71 	if (mp->mnt_flag & (MNT_UPDATE | MNT_ROOTFS))
72 		return (EOPNOTSUPP);
73 
74 	MALLOC(fmp, struct devfs_mount *, sizeof(struct devfs_mount),
75 	    M_DEVFS, M_WAITOK | M_ZERO);
76 	MALLOC(fmp->dm_dirent, struct devfs_dirent **,
77 	    sizeof(struct devfs_dirent *) * NDEVFSINO,
78 	    M_DEVFS, M_WAITOK | M_ZERO);
79 	lockinit(&fmp->dm_lock, PVFS, "devfs", 0, LK_NOPAUSE);
80 
81 	mp->mnt_flag |= MNT_LOCAL;
82 #ifdef MAC
83 	mp->mnt_flag |= MNT_MULTILABEL;
84 #endif
85 	fmp->dm_mount = mp;
86 	mp->mnt_data = (qaddr_t) fmp;
87 	vfs_getnewfsid(mp);
88 
89 	fmp->dm_inode = DEVFSINOMOUNT;
90 
91 	fmp->dm_rootdir = devfs_vmkdir("(root)", 6, NULL);
92 	fmp->dm_rootdir->de_inode = 2;
93 #ifdef MAC
94 	mac_create_devfs_directory(mp, "", 0, fmp->dm_rootdir);
95 #endif
96 	fmp->dm_basedir = fmp->dm_rootdir;
97 	devfs_rules_newmount(fmp, td);
98 
99 	error = devfs_root(mp, &rvp, td);
100 	if (error) {
101 		lockdestroy(&fmp->dm_lock);
102 		FREE(fmp, M_DEVFS);
103 		return (error);
104 	}
105 
106 	VOP_UNLOCK(rvp, 0, td);
107 
108 	vfs_mountedfrom(mp, "devfs");
109 
110 	return (0);
111 }
112 
113 static int
114 devfs_unmount(mp, mntflags, td)
115 	struct mount *mp;
116 	int mntflags;
117 	struct thread *td;
118 {
119 	int error;
120 	int flags = 0;
121 	struct devfs_mount *fmp;
122 
123 	fmp = VFSTODEVFS(mp);
124 	/* There is 1 extra root vnode reference from devfs_mount(). */
125 	error = vflush(mp, 1, flags, td);
126 	if (error)
127 		return (error);
128 	devfs_purge(fmp->dm_rootdir);
129 	mp->mnt_data = 0;
130 	lockdestroy(&fmp->dm_lock);
131 	free(fmp->dm_dirent, M_DEVFS);
132 	free(fmp, M_DEVFS);
133 	return 0;
134 }
135 
136 /* Return locked reference to root.  */
137 
138 static int
139 devfs_root(mp, vpp, td)
140 	struct mount *mp;
141 	struct vnode **vpp;
142 	struct thread *td;
143 {
144 	int error;
145 	struct vnode *vp;
146 	struct devfs_mount *dmp;
147 
148 	dmp = VFSTODEVFS(mp);
149 	error = devfs_allocv(dmp->dm_rootdir, mp, &vp, td);
150 	if (error)
151 		return (error);
152 	vp->v_vflag |= VV_ROOT;
153 	*vpp = vp;
154 	return (0);
155 }
156 
157 static int
158 devfs_statfs(mp, sbp, td)
159 	struct mount *mp;
160 	struct statfs *sbp;
161 	struct thread *td;
162 {
163 
164 	sbp->f_flags = 0;
165 	sbp->f_bsize = DEV_BSIZE;
166 	sbp->f_iosize = DEV_BSIZE;
167 	sbp->f_blocks = 2;		/* 1K to keep df happy */
168 	sbp->f_bfree = 0;
169 	sbp->f_bavail = 0;
170 	sbp->f_files = 0;
171 	sbp->f_ffree = 0;
172 	return (0);
173 }
174 
175 static struct vfsops devfs_vfsops = {
176 	.vfs_mount =		devfs_mount,
177 	.vfs_root =		devfs_root,
178 	.vfs_statfs =		devfs_statfs,
179 	.vfs_unmount =		devfs_unmount,
180 };
181 
182 VFS_SET(devfs_vfsops, devfs, VFCF_SYNTHETIC);
183