xref: /dflybsd-src/sys/vfs/devfs/devfs_vfsops.c (revision 3e82b46c18bc48fdb3c1d60729c7661b3a0bf6bf)
1 /*
2  * Copyright (c) 2009 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Alex Hornung <ahornung@gmail.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/mount.h>
38 #include <sys/vnode.h>
39 #include <sys/jail.h>
40 #include <vfs/devfs/devfs.h>
41 
42 MALLOC_DECLARE(M_DEVFS);
43 
44 extern struct vop_ops devfs_vnode_norm_vops;
45 extern struct vop_ops devfs_vnode_dev_vops;
46 extern struct lock 	devfs_lock;
47 
48 static int	devfs_mount (struct mount *mp, char *path, caddr_t data,
49 				  struct ucred *cred);
50 static int	devfs_statfs (struct mount *mp, struct statfs *sbp,
51 				struct ucred *cred);
52 static int	devfs_unmount (struct mount *mp, int mntflags);
53 int			devfs_root(struct mount *mp, struct vnode **vpp);
54 
55 /*
56  * VFS Operations.
57  *
58  * mount system call
59  */
60 /* ARGSUSED */
61 static int
62 devfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
63 {
64 	size_t size;
65 
66 	devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_mount() called!\n");
67 
68 	if (mp->mnt_flag & MNT_UPDATE)
69 		return (EOPNOTSUPP);
70 
71 
72 	mp->mnt_flag |= MNT_LOCAL;
73 	mp->mnt_kern_flag |= MNTK_NOSTKMNT;
74 	mp->mnt_data = 0;
75 	vfs_getnewfsid(mp);
76 
77 	size = sizeof("devfs") - 1;
78 	bcopy("devfs", mp->mnt_stat.f_mntfromname, size);
79 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
80 	devfs_statfs(mp, &mp->mnt_stat, cred);
81 
82 	//XXX: save other mount info passed from userland or so.
83 	mp->mnt_data = kmalloc(sizeof(struct devfs_mnt_data), M_DEVFS, M_WAITOK);
84 
85 	lockmgr(&devfs_lock, LK_EXCLUSIVE);
86 	DEVFS_MNTDATA(mp)->jailed = jailed(cred);
87 	DEVFS_MNTDATA(mp)->mntonnamelen = strlen(mp->mnt_stat.f_mntonname);
88 	DEVFS_MNTDATA(mp)->leak_count = 0;
89 	DEVFS_MNTDATA(mp)->root_node = devfs_allocp(Proot, "", NULL, mp, NULL);
90 	KKASSERT(DEVFS_MNTDATA(mp)->root_node);
91 	TAILQ_INIT(DEVFS_ORPHANLIST(mp));
92 	lockmgr(&devfs_lock, LK_RELEASE);
93 
94 	vfs_add_vnodeops(mp, &devfs_vnode_norm_vops, &mp->mnt_vn_norm_ops);
95 	vfs_add_vnodeops(mp, &devfs_vnode_dev_vops, &mp->mnt_vn_spec_ops);
96 
97 	devfs_debug(DEVFS_DEBUG_DEBUG, "calling devfs_mount_add\n");
98 	devfs_mount_add(DEVFS_MNTDATA(mp));
99 
100 	return (0);
101 }
102 
103 /*
104  * unmount system call
105  */
106 static int
107 devfs_unmount(struct mount *mp, int mntflags)
108 {
109 	int error = 0;
110 	int flags = 0;
111 
112 	devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_unmount() called!\n");
113 
114 	if (mntflags & MNT_FORCE)
115 		flags |= FORCECLOSE;
116 
117 	error = vflush(mp, 0, flags);
118 
119 	if (error)
120 		return (error);
121 
122 	devfs_debug(DEVFS_DEBUG_DEBUG, "There were %d devfs_node orphans left\n", devfs_tracer_orphan_count(mp, 1));
123 	devfs_debug(DEVFS_DEBUG_DEBUG, "There are %d devfs_node orphans left\n", devfs_tracer_orphan_count(mp, 0));
124 	devfs_mount_del(DEVFS_MNTDATA(mp));
125 	kfree(mp->mnt_data, M_DEVFS);
126 
127 	return (0);
128 }
129 
130 /*
131  * Sets *vpp to the root procfs vnode, referenced and exclusively locked
132  */
133 int
134 devfs_root(struct mount *mp, struct vnode **vpp)
135 {
136 	int ret;
137 	devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_root() called!\n");
138 	lockmgr(&devfs_lock, LK_EXCLUSIVE);
139 	ret = devfs_allocv(vpp, DEVFS_MNTDATA(mp)->root_node);
140 	lockmgr(&devfs_lock, LK_RELEASE);
141 	return ret;
142 }
143 
144 /*
145  * Get file system statistics.
146  */
147 static int
148 devfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
149 {
150 	devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_stat() called!\n");
151 	sbp->f_bsize = DEV_BSIZE;
152 	sbp->f_iosize = DEV_BSIZE;
153 	sbp->f_blocks = 2;	/* avoid divide by zero in some df's */
154 	sbp->f_bfree = 0;
155 	sbp->f_bavail = 0;
156 	sbp->f_files = 0;
157 	sbp->f_ffree = 0;
158 
159 	if (sbp != &mp->mnt_stat) {
160 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
161 		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
162 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
163 	}
164 
165 	return (0);
166 }
167 
168 static struct vfsops devfs_vfsops = {
169 	.vfs_mount =    	devfs_mount,
170 	.vfs_unmount =    	devfs_unmount,
171 	.vfs_root =    		devfs_root,
172 	.vfs_statfs =    	devfs_statfs,
173 	.vfs_sync =    		vfs_stdsync
174 };
175 
176 VFS_SET(devfs_vfsops, devfs, VFCF_SYNTHETIC);
177 MODULE_VERSION(devfs, 1);
178