fdesc_vfsops.c revision 1.14 1 /* $NetBSD: fdesc_vfsops.c,v 1.14 1994/09/15 03:42:37 mycroft Exp $ */
2
3 /*
4 * Copyright (c) 1992, 1993
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 * from: Id: fdesc_vfsops.c,v 1.9 1993/04/06 15:28:33 jsp Exp
39 * @(#)fdesc_vfsops.c 8.4 (Berkeley) 1/21/94
40 */
41
42 /*
43 * /dev/fd Filesystem
44 */
45
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/time.h>
49 #include <sys/types.h>
50 #include <sys/proc.h>
51 #include <sys/resourcevar.h>
52 #include <sys/filedesc.h>
53 #include <sys/vnode.h>
54 #include <sys/mount.h>
55 #include <sys/namei.h>
56 #include <sys/malloc.h>
57 #include <miscfs/fdesc/fdesc.h>
58
59 /*
60 * Mount the per-process file descriptors (/dev/fd)
61 */
62 int
63 fdesc_mount(mp, path, data, ndp, p)
64 struct mount *mp;
65 char *path;
66 caddr_t data;
67 struct nameidata *ndp;
68 struct proc *p;
69 {
70 int error = 0;
71 u_int size;
72 struct fdescmount *fmp;
73 struct vnode *rvp;
74
75 /*
76 * Update is a no-op
77 */
78 if (mp->mnt_flag & MNT_UPDATE)
79 return (EOPNOTSUPP);
80
81 error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp);
82 if (error)
83 return (error);
84
85 MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount),
86 M_UFSMNT, M_WAITOK); /* XXX */
87 rvp->v_type = VDIR;
88 rvp->v_flag |= VROOT;
89 fmp->f_root = rvp;
90 mp->mnt_flag |= MNT_LOCAL;
91 mp->mnt_data = (qaddr_t)fmp;
92 getnewfsid(mp, makefstype(MOUNT_FDESC));
93
94 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
95 bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
96 bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
97 bcopy("fdesc", mp->mnt_stat.f_mntfromname, sizeof("fdesc"));
98 (void)fdesc_statfs(mp, &mp->mnt_stat, p);
99 return (0);
100 }
101
102 int
103 fdesc_start(mp, flags, p)
104 struct mount *mp;
105 int flags;
106 struct proc *p;
107 {
108 return (0);
109 }
110
111 int
112 fdesc_unmount(mp, mntflags, p)
113 struct mount *mp;
114 int mntflags;
115 struct proc *p;
116 {
117 int error;
118 int flags = 0;
119 extern int doforce;
120 struct vnode *rootvp = VFSTOFDESC(mp)->f_root;
121
122 if (mntflags & MNT_FORCE) {
123 /* fdesc can never be rootfs so don't check for it */
124 if (!doforce)
125 return (EINVAL);
126 flags |= FORCECLOSE;
127 }
128
129 /*
130 * Clear out buffer cache. I don't think we
131 * ever get anything cached at this level at the
132 * moment, but who knows...
133 */
134 if (rootvp->v_usecount > 1)
135 return (EBUSY);
136 if (error = vflush(mp, rootvp, flags))
137 return (error);
138
139 /*
140 * Release reference on underlying root vnode
141 */
142 vrele(rootvp);
143 /*
144 * And blow it away for future re-use
145 */
146 vgone(rootvp);
147 /*
148 * Finally, throw away the fdescmount structure
149 */
150 free(mp->mnt_data, M_UFSMNT); /* XXX */
151 mp->mnt_data = 0;
152
153 return (0);
154 }
155
156 int
157 fdesc_root(mp, vpp)
158 struct mount *mp;
159 struct vnode **vpp;
160 {
161 struct vnode *vp;
162
163 /*
164 * Return locked reference to root.
165 */
166 vp = VFSTOFDESC(mp)->f_root;
167 VREF(vp);
168 VOP_LOCK(vp);
169 *vpp = vp;
170 return (0);
171 }
172
173 int
174 fdesc_quotactl(mp, cmd, uid, arg, p)
175 struct mount *mp;
176 int cmd;
177 uid_t uid;
178 caddr_t arg;
179 struct proc *p;
180 {
181
182 return (EOPNOTSUPP);
183 }
184
185 int
186 fdesc_statfs(mp, sbp, p)
187 struct mount *mp;
188 struct statfs *sbp;
189 struct proc *p;
190 {
191 struct filedesc *fdp;
192 int lim;
193 int i;
194 int last;
195 int freefd;
196
197 /*
198 * Compute number of free file descriptors.
199 * [ Strange results will ensue if the open file
200 * limit is ever reduced below the current number
201 * of open files... ]
202 */
203 lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur;
204 fdp = p->p_fd;
205 last = min(fdp->fd_nfiles, lim);
206 freefd = 0;
207 for (i = fdp->fd_freefile; i < last; i++)
208 if (fdp->fd_ofiles[i] == NULL)
209 freefd++;
210
211 /*
212 * Adjust for the fact that the fdesc array may not
213 * have been fully allocated yet.
214 */
215 if (fdp->fd_nfiles < lim)
216 freefd += (lim - fdp->fd_nfiles);
217
218 #ifdef COMPAT_09
219 sbp->f_type = 6;
220 #else
221 sbp->f_type = 0;
222 #endif
223 sbp->f_bsize = DEV_BSIZE;
224 sbp->f_iosize = DEV_BSIZE;
225 sbp->f_blocks = 2; /* 1K to keep df happy */
226 sbp->f_bfree = 0;
227 sbp->f_bavail = 0;
228 sbp->f_files = lim + 1; /* Allow for "." */
229 sbp->f_ffree = freefd; /* See comments above */
230 if (sbp != &mp->mnt_stat) {
231 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
232 bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
233 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
234 }
235 strncpy(&sbp->f_fstypename[0], mp->mnt_op->vfs_name, MFSNAMELEN);
236 sbp->f_fstypename[MFSNAMELEN] = '\0';
237 return (0);
238 }
239
240 int
241 fdesc_sync(mp, waitfor)
242 struct mount *mp;
243 int waitfor;
244 {
245
246 return (0);
247 }
248
249 /*
250 * Fdesc flat namespace lookup.
251 * Currently unsupported.
252 */
253 int
254 fdesc_vget(mp, ino, vpp)
255 struct mount *mp;
256 ino_t ino;
257 struct vnode **vpp;
258 {
259
260 return (EOPNOTSUPP);
261 }
262
263 int
264 fdesc_fhtovp(mp, fhp, setgen, vpp)
265 struct mount *mp;
266 struct fid *fhp;
267 int setgen;
268 struct vnode **vpp;
269 {
270 return (EOPNOTSUPP);
271 }
272
273 int
274 fdesc_vptofh(vp, fhp)
275 struct vnode *vp;
276 struct fid *fhp;
277 {
278
279 return (EOPNOTSUPP);
280 }
281
282 struct vfsops fdesc_vfsops = {
283 MOUNT_FDESC,
284 fdesc_mount,
285 fdesc_start,
286 fdesc_unmount,
287 fdesc_root,
288 fdesc_quotactl,
289 fdesc_statfs,
290 fdesc_sync,
291 fdesc_vget,
292 fdesc_fhtovp,
293 fdesc_vptofh,
294 fdesc_init,
295 };
296