1 | /* $NetBSD: fdesc_vfsops.c,v 1.91 2014/11/09 18:08:06 maxv Exp $ */ |
2 | |
3 | /* |
4 | * Copyright (c) 1992, 1993, 1995 |
5 | * The Regents of the University of California. 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. Redistributions in binary form must reproduce the above copyright |
16 | * notice, this list of conditions and the following disclaimer in the |
17 | * documentation and/or other materials provided with the distribution. |
18 | * 3. Neither the name of the University nor the names of its contributors |
19 | * may be used to endorse or promote products derived from this software |
20 | * without specific prior written permission. |
21 | * |
22 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
23 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
24 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
25 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
26 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
27 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
28 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
29 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
30 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
31 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
32 | * SUCH DAMAGE. |
33 | * |
34 | * @(#)fdesc_vfsops.c 8.10 (Berkeley) 5/14/95 |
35 | * |
36 | * #Id: fdesc_vfsops.c,v 1.9 1993/04/06 15:28:33 jsp Exp # |
37 | */ |
38 | |
39 | /* |
40 | * /dev/fd Filesystem |
41 | */ |
42 | |
43 | #include <sys/cdefs.h> |
44 | __KERNEL_RCSID(0, "$NetBSD: fdesc_vfsops.c,v 1.91 2014/11/09 18:08:06 maxv Exp $" ); |
45 | |
46 | #if defined(_KERNEL_OPT) |
47 | #include "opt_compat_netbsd.h" |
48 | #endif |
49 | |
50 | #include <sys/param.h> |
51 | #include <sys/systm.h> |
52 | #include <sys/sysctl.h> |
53 | #include <sys/time.h> |
54 | #include <sys/proc.h> |
55 | #include <sys/resourcevar.h> |
56 | #include <sys/filedesc.h> |
57 | #include <sys/vnode.h> |
58 | #include <sys/mount.h> |
59 | #include <sys/dirent.h> |
60 | #include <sys/namei.h> |
61 | #include <sys/kauth.h> |
62 | #include <sys/module.h> |
63 | |
64 | #include <miscfs/genfs/genfs.h> |
65 | #include <miscfs/fdesc/fdesc.h> |
66 | |
67 | MODULE(MODULE_CLASS_VFS, fdesc, NULL); |
68 | |
69 | VFS_PROTOS(fdesc); |
70 | |
71 | static struct sysctllog *fdesc_sysctl_log; |
72 | |
73 | /* |
74 | * Mount the per-process file descriptors (/dev/fd) |
75 | */ |
76 | int |
77 | fdesc_mount(struct mount *mp, const char *path, void *data, size_t *data_len) |
78 | { |
79 | struct lwp *l = curlwp; |
80 | int error = 0, ix; |
81 | struct vnode *rvp; |
82 | |
83 | if (mp->mnt_flag & MNT_GETARGS) { |
84 | *data_len = 0; |
85 | return 0; |
86 | } |
87 | /* |
88 | * Update is a no-op |
89 | */ |
90 | if (mp->mnt_flag & MNT_UPDATE) |
91 | return (EOPNOTSUPP); |
92 | |
93 | ix = FD_ROOT; |
94 | error = vcache_get(mp, &ix, sizeof(ix), &rvp); |
95 | if (error) |
96 | return error; |
97 | |
98 | mp->mnt_stat.f_namemax = FDESC_MAXNAMLEN; |
99 | mp->mnt_flag |= MNT_LOCAL; |
100 | mp->mnt_data = rvp; |
101 | vfs_getnewfsid(mp); |
102 | |
103 | error = set_statvfs_info(path, UIO_USERSPACE, "fdesc" , UIO_SYSSPACE, |
104 | mp->mnt_op->vfs_name, mp, l); |
105 | return error; |
106 | } |
107 | |
108 | int |
109 | fdesc_start(struct mount *mp, int flags) |
110 | { |
111 | return (0); |
112 | } |
113 | |
114 | int |
115 | fdesc_unmount(struct mount *mp, int mntflags) |
116 | { |
117 | int error; |
118 | int flags = 0; |
119 | struct vnode *rtvp = mp->mnt_data; |
120 | |
121 | if (mntflags & MNT_FORCE) |
122 | flags |= FORCECLOSE; |
123 | |
124 | if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) |
125 | return (EBUSY); |
126 | if ((error = vflush(mp, rtvp, flags)) != 0) |
127 | return (error); |
128 | |
129 | /* |
130 | * Blow it away for future re-use |
131 | */ |
132 | vgone(rtvp); |
133 | mp->mnt_data = NULL; |
134 | |
135 | return (0); |
136 | } |
137 | |
138 | int |
139 | fdesc_root(struct mount *mp, struct vnode **vpp) |
140 | { |
141 | struct vnode *vp; |
142 | |
143 | /* |
144 | * Return locked reference to root. |
145 | */ |
146 | vp = mp->mnt_data; |
147 | vref(vp); |
148 | vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); |
149 | *vpp = vp; |
150 | return (0); |
151 | } |
152 | |
153 | /*ARGSUSED*/ |
154 | int |
155 | fdesc_sync(struct mount *mp, int waitfor, |
156 | kauth_cred_t uc) |
157 | { |
158 | |
159 | return (0); |
160 | } |
161 | |
162 | /* |
163 | * Fdesc flat namespace lookup. |
164 | * Currently unsupported. |
165 | */ |
166 | int |
167 | fdesc_vget(struct mount *mp, ino_t ino, |
168 | struct vnode **vpp) |
169 | { |
170 | |
171 | return (EOPNOTSUPP); |
172 | } |
173 | |
174 | int |
175 | fdesc_loadvnode(struct mount *mp, struct vnode *vp, |
176 | const void *key, size_t key_len, const void **new_key) |
177 | { |
178 | int ix; |
179 | struct fdescnode *fd; |
180 | |
181 | KASSERT(key_len == sizeof(ix)); |
182 | memcpy(&ix, key, key_len); |
183 | |
184 | fd = kmem_alloc(sizeof(struct fdescnode), KM_SLEEP); |
185 | fd->fd_fd = -1; |
186 | fd->fd_link = NULL; |
187 | fd->fd_ix = ix; |
188 | fd->fd_vnode = vp; |
189 | vp->v_tag = VT_FDESC; |
190 | vp->v_op = fdesc_vnodeop_p; |
191 | vp->v_data = fd; |
192 | switch (ix) { |
193 | case FD_ROOT: |
194 | fd->fd_type = Froot; |
195 | vp->v_type = VDIR; |
196 | vp->v_vflag |= VV_ROOT; |
197 | break; |
198 | case FD_DEVFD: |
199 | fd->fd_type = Fdevfd; |
200 | vp->v_type = VDIR; |
201 | break; |
202 | case FD_CTTY: |
203 | fd->fd_type = Fctty; |
204 | vp->v_type = VCHR; |
205 | break; |
206 | case FD_STDIN: |
207 | fd->fd_type = Flink; |
208 | fd->fd_link = "fd/0" ; |
209 | vp->v_type = VLNK; |
210 | break; |
211 | case FD_STDOUT: |
212 | fd->fd_type = Flink; |
213 | fd->fd_link = "fd/1" ; |
214 | vp->v_type = VLNK; |
215 | break; |
216 | case FD_STDERR: |
217 | fd->fd_type = Flink; |
218 | fd->fd_link = "fd/2" ; |
219 | vp->v_type = VLNK; |
220 | break; |
221 | default: |
222 | KASSERT(ix >= FD_DESC); |
223 | fd->fd_type = Fdesc; |
224 | fd->fd_fd = ix - FD_DESC; |
225 | vp->v_type = VNON; |
226 | break; |
227 | } |
228 | uvm_vnp_setsize(vp, 0); |
229 | *new_key = &fd->fd_ix; |
230 | |
231 | return 0; |
232 | } |
233 | |
234 | extern const struct vnodeopv_desc fdesc_vnodeop_opv_desc; |
235 | |
236 | const struct vnodeopv_desc * const fdesc_vnodeopv_descs[] = { |
237 | &fdesc_vnodeop_opv_desc, |
238 | NULL, |
239 | }; |
240 | |
241 | struct vfsops fdesc_vfsops = { |
242 | .vfs_name = MOUNT_FDESC, |
243 | .vfs_min_mount_data = 0, |
244 | .vfs_mount = fdesc_mount, |
245 | .vfs_start = fdesc_start, |
246 | .vfs_unmount = fdesc_unmount, |
247 | .vfs_root = fdesc_root, |
248 | .vfs_quotactl = (void *)eopnotsupp, |
249 | .vfs_statvfs = genfs_statvfs, |
250 | .vfs_sync = fdesc_sync, |
251 | .vfs_vget = fdesc_vget, |
252 | .vfs_loadvnode = fdesc_loadvnode, |
253 | .vfs_fhtovp = (void *)eopnotsupp, |
254 | .vfs_vptofh = (void *)eopnotsupp, |
255 | .vfs_init = fdesc_init, |
256 | .vfs_done = fdesc_done, |
257 | .vfs_snapshot = (void *)eopnotsupp, |
258 | .vfs_extattrctl = vfs_stdextattrctl, |
259 | .vfs_suspendctl = (void *)eopnotsupp, |
260 | .vfs_renamelock_enter = genfs_renamelock_enter, |
261 | .vfs_renamelock_exit = genfs_renamelock_exit, |
262 | .vfs_fsync = (void *)eopnotsupp, |
263 | .vfs_opv_descs = fdesc_vnodeopv_descs |
264 | }; |
265 | |
266 | static int |
267 | fdesc_modcmd(modcmd_t cmd, void *arg) |
268 | { |
269 | int error; |
270 | |
271 | switch (cmd) { |
272 | case MODULE_CMD_INIT: |
273 | error = vfs_attach(&fdesc_vfsops); |
274 | if (error != 0) |
275 | break; |
276 | sysctl_createv(&fdesc_sysctl_log, 0, NULL, NULL, |
277 | CTLFLAG_PERMANENT, |
278 | CTLTYPE_NODE, "fdesc" , |
279 | SYSCTL_DESCR("File-descriptor file system" ), |
280 | NULL, 0, NULL, 0, |
281 | CTL_VFS, 7, CTL_EOL); |
282 | /* |
283 | * XXX the "7" above could be dynamic, thereby eliminating one |
284 | * more instance of the "number to vfs" mapping problem, but |
285 | * "7" is the order as taken from sys/mount.h |
286 | */ |
287 | break; |
288 | case MODULE_CMD_FINI: |
289 | error = vfs_detach(&fdesc_vfsops); |
290 | if (error != 0) |
291 | break; |
292 | sysctl_teardown(&fdesc_sysctl_log); |
293 | break; |
294 | default: |
295 | error = ENOTTY; |
296 | break; |
297 | } |
298 | |
299 | return (error); |
300 | } |
301 | |