devfs_vfsops.c revision 76166 
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: head/sys/fs/devfs/devfs_vfsops.c 76166 2001-05-01 08:13:21Z markm $
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/lock.h>
43#include <sys/malloc.h>
44#include <sys/mount.h>
45#include <sys/proc.h>
46#include <sys/socket.h>
47#include <sys/vnode.h>
48
49#include <fs/devfs/devfs.h>
50
51MALLOC_DEFINE(M_DEVFS, "DEVFS", "DEVFS data");
52
53static int	devfs_mount __P((struct mount *mp, char *path, caddr_t data,
54				  struct nameidata *ndp, struct proc *p));
55static int	devfs_unmount __P((struct mount *mp, int mntflags,
56				  struct proc *p));
57static int	devfs_root __P((struct mount *mp, struct vnode **vpp));
58static int	devfs_statfs __P((struct mount *mp, struct statfs *sbp,
59				   struct proc *p));
60
61/*
62 * Mount the filesystem
63 */
64static int
65devfs_mount(mp, path, data, ndp, p)
66	struct mount *mp;
67	char *path;
68	caddr_t data;
69	struct nameidata *ndp;
70	struct proc *p;
71{
72	int error;
73	struct devfs_mount *fmp;
74	struct vnode *rvp;
75
76	error = 0;
77	/*
78	 * XXX: flag changes.
79	 */
80	if (mp->mnt_flag & MNT_UPDATE)
81		return (EOPNOTSUPP);
82
83	MALLOC(fmp, struct devfs_mount *, sizeof(struct devfs_mount),
84	    M_DEVFS, M_WAITOK | M_ZERO);
85	lockinit(&fmp->dm_lock, PVFS, "devfs", 0, LK_NOPAUSE);
86
87	mp->mnt_flag |= MNT_LOCAL;
88	mp->mnt_data = (qaddr_t) fmp;
89	vfs_getnewfsid(mp);
90
91	fmp->dm_inode = DEVFSINOMOUNT;
92
93	fmp->dm_rootdir = devfs_vmkdir("(root)", 6, NULL);
94	fmp->dm_rootdir->de_inode = 2;
95	fmp->dm_basedir = fmp->dm_rootdir;
96
97	error = devfs_root(mp, &rvp);
98	if (error) {
99		lockdestroy(&fmp->dm_lock);
100		FREE(fmp, M_DEVFS);
101		return (error);
102	}
103	VOP_UNLOCK(rvp, 0, p);
104
105	bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
106	bcopy("devfs", mp->mnt_stat.f_mntfromname, sizeof("devfs"));
107	(void)devfs_statfs(mp, &mp->mnt_stat, p);
108
109	return (0);
110}
111
112static int
113devfs_unmount(mp, mntflags, p)
114	struct mount *mp;
115	int mntflags;
116	struct proc *p;
117{
118	int error;
119	int flags = 0;
120	struct vnode *rootvp;
121	struct devfs_mount *fmp;
122
123	error = devfs_root(mp, &rootvp);
124	if (error)
125		return (error);
126	fmp = VFSTODEVFS(mp);
127	if (mntflags & MNT_FORCE)
128		flags |= FORCECLOSE;
129	if (rootvp->v_usecount > 2) {
130		vrele(rootvp);
131		return (EBUSY);
132	}
133	error = vflush(mp, rootvp, flags);
134	if (error)
135		return (error);
136	devfs_purge(fmp->dm_rootdir);
137	vput(rootvp);
138	vrele(rootvp);
139	vgone(rootvp);
140	mp->mnt_data = 0;
141	lockdestroy(&fmp->dm_lock);
142	free(fmp, M_DEVFS);
143	return 0;
144}
145
146/* Return locked reference to root.  */
147
148static int
149devfs_root(mp, vpp)
150	struct mount *mp;
151	struct vnode **vpp;
152{
153	int error;
154	struct proc *p;
155	struct vnode *vp;
156	struct devfs_mount *dmp;
157
158	p = curproc;					/* XXX */
159	dmp = VFSTODEVFS(mp);
160	error = devfs_allocv(dmp->dm_rootdir, mp, &vp, p);
161	if (error)
162		return (error);
163	vp->v_flag |= VROOT;
164	*vpp = vp;
165	return (0);
166}
167
168static int
169devfs_statfs(mp, sbp, p)
170	struct mount *mp;
171	struct statfs *sbp;
172	struct proc *p;
173{
174
175	sbp->f_flags = 0;
176	sbp->f_bsize = DEV_BSIZE;
177	sbp->f_iosize = DEV_BSIZE;
178	sbp->f_blocks = 2;		/* 1K to keep df happy */
179	sbp->f_bfree = 0;
180	sbp->f_bavail = 0;
181	sbp->f_files = 0;
182	sbp->f_ffree = 0;
183	if (sbp != &mp->mnt_stat) {
184		sbp->f_type = mp->mnt_vfc->vfc_typenum;
185		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
186		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
187		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
188	}
189	return (0);
190}
191
192static struct vfsops devfs_vfsops = {
193	devfs_mount,
194	vfs_stdstart,
195	devfs_unmount,
196	devfs_root,
197	vfs_stdquotactl,
198	devfs_statfs,
199	vfs_stdsync,
200	vfs_stdvget,
201	vfs_stdfhtovp,
202	vfs_stdcheckexp,
203	vfs_stdvptofh,
204	vfs_stdinit,
205	vfs_stduninit,
206	vfs_stdextattrctl,
207};
208
209VFS_SET(devfs_vfsops, devfs, VFCF_SYNTHETIC);
210