fdesc_vfsops.c revision 1.45 1 /* $NetBSD: fdesc_vfsops.c,v 1.45 2003/12/04 19:38:24 atatat 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 1.45 2003/12/04 19:38:24 atatat 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/namei.h>
60 #include <sys/malloc.h>
61 #include <miscfs/fdesc/fdesc.h>
62
63 int fdesc_mount __P((struct mount *, const char *, void *,
64 struct nameidata *, struct proc *));
65 int fdesc_start __P((struct mount *, int, struct proc *));
66 int fdesc_unmount __P((struct mount *, int, struct proc *));
67 int fdesc_quotactl __P((struct mount *, int, uid_t, caddr_t,
68 struct proc *));
69 int fdesc_statfs __P((struct mount *, struct statfs *, struct proc *));
70 int fdesc_sync __P((struct mount *, int, struct ucred *, struct proc *));
71 int fdesc_vget __P((struct mount *, ino_t, struct vnode **));
72 int fdesc_fhtovp __P((struct mount *, struct fid *, struct vnode **));
73 int fdesc_checkexp __P((struct mount *, struct mbuf *, int *,
74 struct ucred **));
75 int fdesc_vptofh __P((struct vnode *, struct fid *));
76
77 /*
78 * Mount the per-process file descriptors (/dev/fd)
79 */
80 int
81 fdesc_mount(mp, path, data, ndp, p)
82 struct mount *mp;
83 const char *path;
84 void *data;
85 struct nameidata *ndp;
86 struct proc *p;
87 {
88 int error = 0;
89 struct fdescmount *fmp;
90 struct vnode *rvp;
91
92 if (mp->mnt_flag & MNT_GETARGS)
93 return 0;
94 /*
95 * Update is a no-op
96 */
97 if (mp->mnt_flag & MNT_UPDATE)
98 return (EOPNOTSUPP);
99
100 error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp);
101 if (error)
102 return (error);
103
104 MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount),
105 M_UFSMNT, M_WAITOK); /* XXX */
106 rvp->v_type = VDIR;
107 rvp->v_flag |= VROOT;
108 fmp->f_root = rvp;
109 mp->mnt_flag |= MNT_LOCAL;
110 mp->mnt_data = fmp;
111 vfs_getnewfsid(mp);
112
113 error = set_statfs_info(path, UIO_USERSPACE, "fdesc", UIO_SYSSPACE,
114 mp, p);
115 VOP_UNLOCK(rvp, 0);
116 return error;
117 }
118
119 int
120 fdesc_start(mp, flags, p)
121 struct mount *mp;
122 int flags;
123 struct proc *p;
124 {
125 return (0);
126 }
127
128 int
129 fdesc_unmount(mp, mntflags, p)
130 struct mount *mp;
131 int mntflags;
132 struct proc *p;
133 {
134 int error;
135 int flags = 0;
136 struct vnode *rootvp = VFSTOFDESC(mp)->f_root;
137
138 if (mntflags & MNT_FORCE)
139 flags |= FORCECLOSE;
140
141 /*
142 * Clear out buffer cache. I don't think we
143 * ever get anything cached at this level at the
144 * moment, but who knows...
145 */
146 if (rootvp->v_usecount > 1)
147 return (EBUSY);
148 if ((error = vflush(mp, rootvp, flags)) != 0)
149 return (error);
150
151 /*
152 * Release reference on underlying root vnode
153 */
154 vrele(rootvp);
155 /*
156 * And blow it away for future re-use
157 */
158 vgone(rootvp);
159 /*
160 * Finally, throw away the fdescmount structure
161 */
162 free(mp->mnt_data, M_UFSMNT); /* XXX */
163 mp->mnt_data = 0;
164
165 return (0);
166 }
167
168 int
169 fdesc_root(mp, vpp)
170 struct mount *mp;
171 struct vnode **vpp;
172 {
173 struct vnode *vp;
174
175 /*
176 * Return locked reference to root.
177 */
178 vp = VFSTOFDESC(mp)->f_root;
179 VREF(vp);
180 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
181 *vpp = vp;
182 return (0);
183 }
184
185 int
186 fdesc_quotactl(mp, cmd, uid, arg, p)
187 struct mount *mp;
188 int cmd;
189 uid_t uid;
190 caddr_t arg;
191 struct proc *p;
192 {
193
194 return (EOPNOTSUPP);
195 }
196
197 int
198 fdesc_statfs(mp, sbp, p)
199 struct mount *mp;
200 struct statfs *sbp;
201 struct proc *p;
202 {
203 struct filedesc *fdp;
204 int lim;
205 int i;
206 int last;
207 int freefd;
208
209 /*
210 * Compute number of free file descriptors.
211 * [ Strange results will ensue if the open file
212 * limit is ever reduced below the current number
213 * of open files... ]
214 */
215 lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur;
216 fdp = p->p_fd;
217 last = min(fdp->fd_nfiles, lim);
218 freefd = 0;
219 for (i = fdp->fd_freefile; i < last; i++)
220 if (fdp->fd_ofiles[i] == NULL)
221 freefd++;
222
223 /*
224 * Adjust for the fact that the fdesc array may not
225 * have been fully allocated yet.
226 */
227 if (fdp->fd_nfiles < lim)
228 freefd += (lim - fdp->fd_nfiles);
229
230 sbp->f_bsize = DEV_BSIZE;
231 sbp->f_iosize = DEV_BSIZE;
232 sbp->f_blocks = 2; /* 1K to keep df happy */
233 sbp->f_bfree = 0;
234 sbp->f_bavail = 0;
235 sbp->f_files = lim + 1; /* Allow for "." */
236 sbp->f_ffree = freefd; /* See comments above */
237 #ifdef COMPAT_09
238 sbp->f_type = 6;
239 #else
240 sbp->f_type = 0;
241 #endif
242 copy_statfs_info(sbp, mp);
243 return (0);
244 }
245
246 /*ARGSUSED*/
247 int
248 fdesc_sync(mp, waitfor, uc, p)
249 struct mount *mp;
250 int waitfor;
251 struct ucred *uc;
252 struct proc *p;
253 {
254
255 return (0);
256 }
257
258 /*
259 * Fdesc flat namespace lookup.
260 * Currently unsupported.
261 */
262 int
263 fdesc_vget(mp, ino, vpp)
264 struct mount *mp;
265 ino_t ino;
266 struct vnode **vpp;
267 {
268
269 return (EOPNOTSUPP);
270 }
271
272
273 /*ARGSUSED*/
274 int
275 fdesc_fhtovp(mp, fhp, vpp)
276 struct mount *mp;
277 struct fid *fhp;
278 struct vnode **vpp;
279 {
280
281 return (EOPNOTSUPP);
282 }
283
284 /*ARGSUSED*/
285 int
286 fdesc_checkexp(mp, nam, exflagsp, credanonp)
287 struct mount *mp;
288 struct mbuf *nam;
289 int *exflagsp;
290 struct ucred **credanonp;
291 {
292
293 return (EOPNOTSUPP);
294 }
295
296 /*ARGSUSED*/
297 int
298 fdesc_vptofh(vp, fhp)
299 struct vnode *vp;
300 struct fid *fhp;
301 {
302 return (EOPNOTSUPP);
303 }
304
305 SYSCTL_SETUP(sysctl_vfs_fdesc_setup, "sysctl vfs.fdesc subtree setup")
306 {
307
308 sysctl_createv(SYSCTL_PERMANENT,
309 CTLTYPE_NODE, "vfs", NULL,
310 NULL, 0, NULL, 0,
311 CTL_VFS, CTL_EOL);
312 sysctl_createv(SYSCTL_PERMANENT,
313 CTLTYPE_NODE, "fdesc", NULL,
314 NULL, 0, NULL, 0,
315 CTL_VFS, 7, CTL_EOL);
316 /*
317 * XXX the "7" above could be dynamic, thereby eliminating one
318 * more instance of the "number to vfs" mapping problem, but
319 * "7" is the order as taken from sys/mount.h
320 */
321 }
322
323 extern const struct vnodeopv_desc fdesc_vnodeop_opv_desc;
324
325 const struct vnodeopv_desc * const fdesc_vnodeopv_descs[] = {
326 &fdesc_vnodeop_opv_desc,
327 NULL,
328 };
329
330 struct vfsops fdesc_vfsops = {
331 MOUNT_FDESC,
332 fdesc_mount,
333 fdesc_start,
334 fdesc_unmount,
335 fdesc_root,
336 fdesc_quotactl,
337 fdesc_statfs,
338 fdesc_sync,
339 fdesc_vget,
340 fdesc_fhtovp,
341 fdesc_vptofh,
342 fdesc_init,
343 NULL,
344 fdesc_done,
345 NULL,
346 NULL, /* vfs_mountroot */
347 fdesc_checkexp,
348 fdesc_vnodeopv_descs,
349 };
350