xref: /dragonfly/sys/vfs/devfs/devfs_vfsops.c (revision a579280a)
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 <sys/lock.h>
41 #include <sys/devfs.h>
42 
43 MALLOC_DECLARE(M_DEVFS);
44 
45 extern struct vop_ops devfs_vnode_norm_vops;
46 extern struct vop_ops devfs_vnode_dev_vops;
47 extern struct lock 	devfs_lock;
48 
49 static int	devfs_mount (struct mount *mp, char *path, caddr_t data,
50 				  struct ucred *cred);
51 static int	devfs_statfs (struct mount *mp, struct statfs *sbp,
52 				struct ucred *cred);
53 static int	devfs_unmount (struct mount *mp, int mntflags);
54 int			devfs_root(struct mount *mp, struct vnode **vpp);
55 static int	devfs_vget(struct mount *mp, struct vnode *dvp,
56 				ino_t ino, struct vnode **vpp);
57 static int	devfs_fhtovp(struct mount *mp, struct vnode *rootvp,
58 				struct fid *fhp, struct vnode **vpp);
59 static int	devfs_vptofh(struct vnode *vp, struct fid *fhp);
60 
61 
62 /*
63  * VFS Operations.
64  *
65  * mount system call
66  */
67 /* ARGSUSED */
68 static int
69 devfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
70 {
71 	struct devfs_mount_info info;
72 	struct devfs_mnt_data *mnt;
73 	size_t size;
74 	int error;
75 
76 	devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_mount() called!\n");
77 
78 	if (mp->mnt_flag & MNT_UPDATE)
79 		return (EOPNOTSUPP);
80 
81 	if (data == NULL) {
82 		bzero(&info, sizeof(info));
83 	} else {
84 		if ((error = copyin(data, &info, sizeof(info))) != 0)
85 			return (error);
86 	}
87 
88 	mp->mnt_flag |= MNT_LOCAL;
89 	mp->mnt_kern_flag |= MNTK_NOSTKMNT;
90 	mp->mnt_data = NULL;
91 	vfs_getnewfsid(mp);
92 
93 	size = sizeof("devfs") - 1;
94 	bcopy("devfs", mp->mnt_stat.f_mntfromname, size);
95 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
96 	devfs_statfs(mp, &mp->mnt_stat, cred);
97 
98 	/*
99 	 * XXX: save other mount info passed from userland or so.
100 	 */
101 	mnt = kmalloc(sizeof(*mnt), M_DEVFS, M_WAITOK | M_ZERO);
102 
103 	lockmgr(&devfs_lock, LK_EXCLUSIVE);
104 	mp->mnt_data = (qaddr_t)mnt;
105 
106 	if (info.flags & DEVFS_MNT_JAIL)
107 		mnt->jailed = 1;
108 	else
109 		mnt->jailed = jailed(cred);
110 
111 	mnt->leak_count = 0;
112 	mnt->file_count = 0;
113 	mnt->mp = mp;
114 	TAILQ_INIT(&mnt->orphan_list);
115 	mnt->root_node = devfs_allocp(Proot, "", NULL, mp, NULL);
116 	KKASSERT(mnt->root_node);
117 	lockmgr(&devfs_lock, LK_RELEASE);
118 
119 	vfs_add_vnodeops(mp, &devfs_vnode_norm_vops, &mp->mnt_vn_norm_ops);
120 	vfs_add_vnodeops(mp, &devfs_vnode_dev_vops, &mp->mnt_vn_spec_ops);
121 
122 	devfs_debug(DEVFS_DEBUG_DEBUG, "calling devfs_mount_add\n");
123 	devfs_mount_add(mnt);
124 
125 	return (0);
126 }
127 
128 /*
129  * unmount system call
130  */
131 static int
132 devfs_unmount(struct mount *mp, int mntflags)
133 {
134 	int error = 0;
135 	int flags = 0;
136 
137 	devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_unmount() called!\n");
138 
139 	if (mntflags & MNT_FORCE)
140 		flags |= FORCECLOSE;
141 
142 	error = vflush(mp, 0, flags);
143 
144 	if (error)
145 		return (error);
146 	devfs_tracer_orphan_count(mp, 1);
147 	devfs_mount_del(DEVFS_MNTDATA(mp));
148 	kfree(mp->mnt_data, M_DEVFS);
149 	mp->mnt_data = NULL;
150 
151 	return (0);
152 }
153 
154 /*
155  * Sets *vpp to the root procfs vnode, referenced and exclusively locked
156  */
157 int
158 devfs_root(struct mount *mp, struct vnode **vpp)
159 {
160 	int ret;
161 	devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_root() called!\n");
162 	lockmgr(&devfs_lock, LK_EXCLUSIVE);
163 	ret = devfs_allocv(vpp, DEVFS_MNTDATA(mp)->root_node);
164 	lockmgr(&devfs_lock, LK_RELEASE);
165 	return ret;
166 }
167 
168 /*
169  * Get file system statistics.
170  */
171 static int
172 devfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
173 {
174 	devfs_debug(DEVFS_DEBUG_DEBUG, "(vfsops) devfs_stat() called!\n");
175 	sbp->f_bsize = DEV_BSIZE;
176 	sbp->f_iosize = DEV_BSIZE;
177 	sbp->f_blocks = 2;	/* avoid divide by zero in some df's */
178 	sbp->f_bfree = 0;
179 	sbp->f_bavail = 0;
180 	sbp->f_files = (DEVFS_MNTDATA(mp))?(DEVFS_MNTDATA(mp)->file_count):0;
181 	sbp->f_ffree = 0;
182 
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_mntfromname, sbp->f_mntfromname, MNAMELEN);
187 	}
188 
189 	return (0);
190 }
191 
192 static int
193 devfs_fhtovp(struct mount *mp, struct vnode *rootvp,
194 	   struct fid *fhp, struct vnode **vpp)
195 {
196 	struct vnode		*vp;
197 	struct devfs_fid	*dfhp;
198 
199 	dfhp = (struct devfs_fid *)fhp;
200 
201 	if (dfhp->fid_gen != boottime.tv_sec)
202 		return EINVAL;
203 
204 	vp = devfs_inode_to_vnode(mp, dfhp->fid_ino);
205 
206 	if (vp == NULL)
207 		return ENOENT;
208 
209 	*vpp = vp;
210 	return 0;
211 }
212 
213 /*
214  * Vnode pointer to File handle
215  */
216 /* ARGSUSED */
217 static int
218 devfs_vptofh(struct vnode *vp, struct fid *fhp)
219 {
220 	struct devfs_node	*node;
221 	struct devfs_fid	*dfhp;
222 
223 	if ((node = DEVFS_NODE(vp)) != NULL) {
224 		dfhp = (struct devfs_fid *)fhp;
225 		dfhp->fid_len = sizeof(struct devfs_fid);
226 		dfhp->fid_ino = node->d_dir.d_ino;
227 		dfhp->fid_gen = boottime.tv_sec;
228 	} else {
229 		return ENOENT;
230 	}
231 
232 	return (0);
233 }
234 
235 static int
236 devfs_vget(struct mount *mp, struct vnode *dvp, ino_t ino, struct vnode **vpp)
237 {
238 	struct vnode *vp;
239 	vp = devfs_inode_to_vnode(mp, ino);
240 
241 	if (vp == NULL)
242 		return ENOENT;
243 
244 	*vpp = vp;
245 	return 0;
246 }
247 
248 
249 static struct vfsops devfs_vfsops = {
250 	.vfs_mount 	=   devfs_mount,
251 	.vfs_unmount =  devfs_unmount,
252 	.vfs_root 	=   devfs_root,
253 	.vfs_statfs =   devfs_statfs,
254 	.vfs_sync 	=   vfs_stdsync,
255 	.vfs_vget	= 	devfs_vget,
256 	.vfs_vptofh	= 	devfs_vptofh,
257 	.vfs_fhtovp	= 	devfs_fhtovp
258 };
259 
260 VFS_SET(devfs_vfsops, devfs, VFCF_SYNTHETIC);
261 MODULE_VERSION(devfs, 1);
262