fdesc_vfsops.c revision 1.38 1 /* $NetBSD: fdesc_vfsops.c,v 1.38 2002/09/21 18:09:27 christos 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. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * @(#)fdesc_vfsops.c 8.10 (Berkeley) 5/14/95
39 *
40 * #Id: fdesc_vfsops.c,v 1.9 1993/04/06 15:28:33 jsp Exp #
41 */
42
43 /*
44 * /dev/fd Filesystem
45 */
46
47 #include <sys/cdefs.h>
48 __KERNEL_RCSID(0, "$NetBSD: fdesc_vfsops.c,v 1.38 2002/09/21 18:09:27 christos Exp $");
49
50 #if defined(_KERNEL_OPT)
51 #include "opt_compat_netbsd.h"
52 #endif
53
54 #include <sys/param.h>
55 #include <sys/systm.h>
56 #include <sys/time.h>
57 #include <sys/proc.h>
58 #include <sys/resourcevar.h>
59 #include <sys/filedesc.h>
60 #include <sys/vnode.h>
61 #include <sys/mount.h>
62 #include <sys/namei.h>
63 #include <sys/malloc.h>
64 #include <miscfs/fdesc/fdesc.h>
65
66 int fdesc_mount __P((struct mount *, const char *, void *,
67 struct nameidata *, struct proc *));
68 int fdesc_start __P((struct mount *, int, struct proc *));
69 int fdesc_unmount __P((struct mount *, int, struct proc *));
70 int fdesc_quotactl __P((struct mount *, int, uid_t, caddr_t,
71 struct proc *));
72 int fdesc_statfs __P((struct mount *, struct statfs *, struct proc *));
73 int fdesc_sync __P((struct mount *, int, struct ucred *, struct proc *));
74 int fdesc_vget __P((struct mount *, ino_t, struct vnode **));
75 int fdesc_fhtovp __P((struct mount *, struct fid *, struct vnode **));
76 int fdesc_checkexp __P((struct mount *, struct mbuf *, int *,
77 struct ucred **));
78 int fdesc_vptofh __P((struct vnode *, struct fid *));
79 int fdesc_sysctl __P((int *, u_int, void *, size_t *, void *, size_t,
80 struct proc *));
81
82 /*
83 * Mount the per-process file descriptors (/dev/fd)
84 */
85 int
86 fdesc_mount(mp, path, data, ndp, p)
87 struct mount *mp;
88 const char *path;
89 void *data;
90 struct nameidata *ndp;
91 struct proc *p;
92 {
93 int error = 0;
94 size_t size;
95 struct fdescmount *fmp;
96 struct vnode *rvp;
97
98 if (mp->mnt_flag & MNT_GETARGS)
99 return 0;
100 /*
101 * Update is a no-op
102 */
103 if (mp->mnt_flag & MNT_UPDATE)
104 return (EOPNOTSUPP);
105
106 error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp);
107 if (error)
108 return (error);
109
110 MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount),
111 M_UFSMNT, M_WAITOK); /* XXX */
112 rvp->v_type = VDIR;
113 rvp->v_flag |= VROOT;
114 fmp->f_root = rvp;
115 mp->mnt_flag |= MNT_LOCAL;
116 mp->mnt_data = fmp;
117 vfs_getnewfsid(mp);
118
119 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
120 memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size);
121 memset(mp->mnt_stat.f_mntfromname, 0, MNAMELEN);
122 memcpy(mp->mnt_stat.f_mntfromname, "fdesc", sizeof("fdesc"));
123 VOP_UNLOCK(rvp, 0);
124 return (0);
125 }
126
127 int
128 fdesc_start(mp, flags, p)
129 struct mount *mp;
130 int flags;
131 struct proc *p;
132 {
133 return (0);
134 }
135
136 int
137 fdesc_unmount(mp, mntflags, p)
138 struct mount *mp;
139 int mntflags;
140 struct proc *p;
141 {
142 int error;
143 int flags = 0;
144 struct vnode *rootvp = VFSTOFDESC(mp)->f_root;
145
146 if (mntflags & MNT_FORCE)
147 flags |= FORCECLOSE;
148
149 /*
150 * Clear out buffer cache. I don't think we
151 * ever get anything cached at this level at the
152 * moment, but who knows...
153 */
154 if (rootvp->v_usecount > 1)
155 return (EBUSY);
156 if ((error = vflush(mp, rootvp, flags)) != 0)
157 return (error);
158
159 /*
160 * Release reference on underlying root vnode
161 */
162 vrele(rootvp);
163 /*
164 * And blow it away for future re-use
165 */
166 vgone(rootvp);
167 /*
168 * Finally, throw away the fdescmount structure
169 */
170 free(mp->mnt_data, M_UFSMNT); /* XXX */
171 mp->mnt_data = 0;
172
173 return (0);
174 }
175
176 int
177 fdesc_root(mp, vpp)
178 struct mount *mp;
179 struct vnode **vpp;
180 {
181 struct vnode *vp;
182
183 /*
184 * Return locked reference to root.
185 */
186 vp = VFSTOFDESC(mp)->f_root;
187 VREF(vp);
188 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
189 *vpp = vp;
190 return (0);
191 }
192
193 int
194 fdesc_quotactl(mp, cmd, uid, arg, p)
195 struct mount *mp;
196 int cmd;
197 uid_t uid;
198 caddr_t arg;
199 struct proc *p;
200 {
201
202 return (EOPNOTSUPP);
203 }
204
205 int
206 fdesc_statfs(mp, sbp, p)
207 struct mount *mp;
208 struct statfs *sbp;
209 struct proc *p;
210 {
211 struct filedesc *fdp;
212 int lim;
213 int i;
214 int last;
215 int freefd;
216
217 /*
218 * Compute number of free file descriptors.
219 * [ Strange results will ensue if the open file
220 * limit is ever reduced below the current number
221 * of open files... ]
222 */
223 lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur;
224 fdp = p->p_fd;
225 last = min(fdp->fd_nfiles, lim);
226 freefd = 0;
227 for (i = fdp->fd_freefile; i < last; i++)
228 if (fdp->fd_ofiles[i] == NULL)
229 freefd++;
230
231 /*
232 * Adjust for the fact that the fdesc array may not
233 * have been fully allocated yet.
234 */
235 if (fdp->fd_nfiles < lim)
236 freefd += (lim - fdp->fd_nfiles);
237
238 sbp->f_bsize = DEV_BSIZE;
239 sbp->f_iosize = DEV_BSIZE;
240 sbp->f_blocks = 2; /* 1K to keep df happy */
241 sbp->f_bfree = 0;
242 sbp->f_bavail = 0;
243 sbp->f_files = lim + 1; /* Allow for "." */
244 sbp->f_ffree = freefd; /* See comments above */
245 #ifdef COMPAT_09
246 sbp->f_type = 6;
247 #else
248 sbp->f_type = 0;
249 #endif
250 if (sbp != &mp->mnt_stat) {
251 memcpy(&sbp->f_fsid, &mp->mnt_stat.f_fsid, sizeof(sbp->f_fsid));
252 memcpy(sbp->f_mntonname, mp->mnt_stat.f_mntonname, MNAMELEN);
253 memcpy(sbp->f_mntfromname, mp->mnt_stat.f_mntfromname, MNAMELEN);
254 }
255 strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, MFSNAMELEN);
256 return (0);
257 }
258
259 /*ARGSUSED*/
260 int
261 fdesc_sync(mp, waitfor, uc, p)
262 struct mount *mp;
263 int waitfor;
264 struct ucred *uc;
265 struct proc *p;
266 {
267
268 return (0);
269 }
270
271 /*
272 * Fdesc flat namespace lookup.
273 * Currently unsupported.
274 */
275 int
276 fdesc_vget(mp, ino, vpp)
277 struct mount *mp;
278 ino_t ino;
279 struct vnode **vpp;
280 {
281
282 return (EOPNOTSUPP);
283 }
284
285
286 /*ARGSUSED*/
287 int
288 fdesc_fhtovp(mp, fhp, vpp)
289 struct mount *mp;
290 struct fid *fhp;
291 struct vnode **vpp;
292 {
293
294 return (EOPNOTSUPP);
295 }
296
297 /*ARGSUSED*/
298 int
299 fdesc_checkexp(mp, nam, exflagsp, credanonp)
300 struct mount *mp;
301 struct mbuf *nam;
302 int *exflagsp;
303 struct ucred **credanonp;
304 {
305
306 return (EOPNOTSUPP);
307 }
308
309 /*ARGSUSED*/
310 int
311 fdesc_vptofh(vp, fhp)
312 struct vnode *vp;
313 struct fid *fhp;
314 {
315 return (EOPNOTSUPP);
316 }
317
318 int
319 fdesc_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
320 int *name;
321 u_int namelen;
322 void *oldp;
323 size_t *oldlenp;
324 void *newp;
325 size_t newlen;
326 struct proc *p;
327 {
328 return (EOPNOTSUPP);
329 }
330
331 extern const struct vnodeopv_desc fdesc_vnodeop_opv_desc;
332
333 const struct vnodeopv_desc * const fdesc_vnodeopv_descs[] = {
334 &fdesc_vnodeop_opv_desc,
335 NULL,
336 };
337
338 struct vfsops fdesc_vfsops = {
339 MOUNT_FDESC,
340 fdesc_mount,
341 fdesc_start,
342 fdesc_unmount,
343 fdesc_root,
344 fdesc_quotactl,
345 fdesc_statfs,
346 fdesc_sync,
347 fdesc_vget,
348 fdesc_fhtovp,
349 fdesc_vptofh,
350 fdesc_init,
351 NULL,
352 fdesc_done,
353 fdesc_sysctl,
354 NULL, /* vfs_mountroot */
355 fdesc_checkexp,
356 fdesc_vnodeopv_descs,
357 };
358