xref: /freebsd/sys/fs/devfs/devfs_vfsops.c (revision d1ba25f456132eabc6f1244e4bbbf3d19e8f3a31)
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/proc.h>
43 #include <sys/vnode.h>
44 #include <sys/mount.h>
45 #include <sys/malloc.h>
46 
47 #include <fs/devfs/devfs.h>
48 
49 MALLOC_DEFINE(M_DEVFS, "DEVFS", "DEVFS data");
50 
51 static int	devfs_mount __P((struct mount *mp, char *path, caddr_t data,
52 				  struct nameidata *ndp, struct proc *p));
53 static int	devfs_unmount __P((struct mount *mp, int mntflags,
54 				  struct proc *p));
55 static int	devfs_root __P((struct mount *mp, struct vnode **vpp));
56 static int	devfs_statfs __P((struct mount *mp, struct statfs *sbp,
57 				   struct proc *p));
58 
59 /*
60  * Mount the filesystem
61  */
62 static int
63 devfs_mount(mp, path, data, ndp, p)
64 	struct mount *mp;
65 	char *path;
66 	caddr_t data;
67 	struct nameidata *ndp;
68 	struct proc *p;
69 {
70 	int error;
71 	size_t size;
72 	struct devfs_mount *fmp;
73 	struct vnode *rvp;
74 
75 	error = 0;
76 	/*
77 	 * XXX: flag changes.
78 	 */
79 	if (mp->mnt_flag & MNT_UPDATE)
80 		return (EOPNOTSUPP);
81 
82 	MALLOC(fmp, struct devfs_mount *, sizeof(struct devfs_mount),
83 	    M_DEVFS, M_WAITOK);
84 	bzero(fmp, sizeof(*fmp));
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 	if (path != NULL) {
106 		(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
107 	} else {
108 		strcpy(mp->mnt_stat.f_mntonname, "/");
109 		size = 1;
110 	}
111 	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
112 	bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
113 	bcopy("devfs", mp->mnt_stat.f_mntfromname, sizeof("devfs"));
114 	(void)devfs_statfs(mp, &mp->mnt_stat, p);
115 
116 	return (0);
117 }
118 
119 static int
120 devfs_unmount(mp, mntflags, p)
121 	struct mount *mp;
122 	int mntflags;
123 	struct proc *p;
124 {
125 	int error;
126 	int flags = 0;
127 	struct vnode *rootvp;
128 	struct devfs_mount *fmp;
129 
130 	error = devfs_root(mp, &rootvp);
131 	if (error)
132 		return (error);
133 	fmp = VFSTODEVFS(mp);
134 	if (mntflags & MNT_FORCE)
135 		flags |= FORCECLOSE;
136 	if (rootvp->v_usecount > 2) {
137 		vrele(rootvp);
138 		return (EBUSY);
139 	}
140 	error = vflush(mp, rootvp, flags);
141 	if (error)
142 		return (error);
143 	devfs_purge(fmp->dm_rootdir);
144 	vput(rootvp);
145 	vrele(rootvp);
146 	vgone(rootvp);
147 	mp->mnt_data = 0;
148 	lockdestroy(&fmp->dm_lock);
149 	free(fmp, M_DEVFS);
150 	return 0;
151 }
152 
153 /* Return locked reference to root.  */
154 
155 static int
156 devfs_root(mp, vpp)
157 	struct mount *mp;
158 	struct vnode **vpp;
159 {
160 	int error;
161 	struct proc *p;
162 	struct vnode *vp;
163 	struct devfs_mount *dmp;
164 
165 	p = curproc;					/* XXX */
166 	dmp = VFSTODEVFS(mp);
167 	error = devfs_allocv(dmp->dm_rootdir, mp, &vp, p);
168 	if (error)
169 		return (error);
170 	vp->v_flag |= VROOT;
171 	*vpp = vp;
172 	return (0);
173 }
174 
175 static int
176 devfs_statfs(mp, sbp, p)
177 	struct mount *mp;
178 	struct statfs *sbp;
179 	struct proc *p;
180 {
181 
182 	sbp->f_flags = 0;
183 	sbp->f_bsize = DEV_BSIZE;
184 	sbp->f_iosize = DEV_BSIZE;
185 	sbp->f_blocks = 2;		/* 1K to keep df happy */
186 	sbp->f_bfree = 0;
187 	sbp->f_bavail = 0;
188 	sbp->f_files = 0;
189 	sbp->f_ffree = 0;
190 	if (sbp != &mp->mnt_stat) {
191 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
192 		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
193 		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
194 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
195 	}
196 	return (0);
197 }
198 
199 static struct vfsops devfs_vfsops = {
200 	devfs_mount,
201 	vfs_stdstart,
202 	devfs_unmount,
203 	devfs_root,
204 	vfs_stdquotactl,
205 	devfs_statfs,
206 	vfs_stdsync,
207 	vfs_stdvget,
208 	vfs_stdfhtovp,
209 	vfs_stdcheckexp,
210 	vfs_stdvptofh,
211 	vfs_stdinit,
212 	vfs_stduninit,
213 	vfs_stdextattrctl,
214 };
215 
216 VFS_SET(devfs_vfsops, devfs, VFCF_SYNTHETIC);
217