xref: /freebsd/sys/fs/devfs/devfs_vfsops.c (revision b52b9d56d4e96089873a75f9e29062eec19fabba)
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 #ifndef NODEVFS
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/kernel.h>
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/mount.h>
46 #include <sys/proc.h>
47 #include <sys/vnode.h>
48 
49 #include <fs/devfs/devfs.h>
50 
51 MALLOC_DEFINE(M_DEVFS, "DEVFS", "DEVFS data");
52 
53 static int	devfs_mount(struct mount *mp, struct nameidata *ndp,
54 				  struct thread *td);
55 static int	devfs_unmount(struct mount *mp, int mntflags,
56 				  struct thread *td);
57 static int	devfs_root(struct mount *mp, struct vnode **vpp);
58 static int	devfs_statfs(struct mount *mp, struct statfs *sbp,
59 				   struct thread *td);
60 
61 /*
62  * Mount the filesystem
63  */
64 static int
65 devfs_mount(mp, ndp, td)
66 	struct mount *mp;
67 	struct nameidata *ndp;
68 	struct thread *td;
69 {
70 	int error;
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 | M_ZERO);
83 	lockinit(&fmp->dm_lock, PVFS, "devfs", 0, LK_NOPAUSE);
84 
85 	mp->mnt_flag |= MNT_LOCAL;
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 	fmp->dm_basedir = fmp->dm_rootdir;
94 	devfs_rules_newmount(fmp, td);
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, td);
103 
104 	bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
105 	bcopy("devfs", mp->mnt_stat.f_mntfromname, sizeof("devfs"));
106 	(void)devfs_statfs(mp, &mp->mnt_stat, td);
107 
108 	return (0);
109 }
110 
111 static int
112 devfs_unmount(mp, mntflags, td)
113 	struct mount *mp;
114 	int mntflags;
115 	struct thread *td;
116 {
117 	int error;
118 	int flags = 0;
119 	struct devfs_mount *fmp;
120 
121 	fmp = VFSTODEVFS(mp);
122 	if (mntflags & MNT_FORCE)
123 		flags |= FORCECLOSE;
124 	/* There is 1 extra root vnode reference from devfs_mount(). */
125 	error = vflush(mp, 1, flags);
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, M_DEVFS);
132 	return 0;
133 }
134 
135 /* Return locked reference to root.  */
136 
137 static int
138 devfs_root(mp, vpp)
139 	struct mount *mp;
140 	struct vnode **vpp;
141 {
142 	int error;
143 	struct thread *td;
144 	struct vnode *vp;
145 	struct devfs_mount *dmp;
146 
147 	td = curthread;					/* XXX */
148 	dmp = VFSTODEVFS(mp);
149 	error = devfs_allocv(dmp->dm_rootdir, mp, &vp, td);
150 	if (error)
151 		return (error);
152 	vp->v_flag |= VROOT;
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 	if (sbp != &mp->mnt_stat) {
173 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
174 		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
175 		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
176 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
177 	}
178 	return (0);
179 }
180 
181 static struct vfsops devfs_vfsops = {
182 	NULL,
183 	vfs_stdstart,
184 	devfs_unmount,
185 	devfs_root,
186 	vfs_stdquotactl,
187 	devfs_statfs,
188 	vfs_stdsync,
189 	vfs_stdvget,
190 	vfs_stdfhtovp,
191 	vfs_stdcheckexp,
192 	vfs_stdvptofh,
193 	vfs_stdinit,
194 	vfs_stduninit,
195 	vfs_stdextattrctl,
196 	devfs_mount,
197 };
198 
199 VFS_SET(devfs_vfsops, devfs, VFCF_SYNTHETIC);
200 #endif
201