Initial import from FreeBSD RELENG_4:
[dragonfly.git] / sys / vfs / fdesc / fdesc_vnops.c
CommitLineData
984263bc
MD
1/*
2 * Copyright (c) 1992, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software donated to Berkeley by
6 * Jan-Simon Pendry.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
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 the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)fdesc_vnops.c 8.9 (Berkeley) 1/21/94
37 *
38 * $FreeBSD: src/sys/miscfs/fdesc/fdesc_vnops.c,v 1.47.2.1 2001/10/22 22:49:26 chris Exp $
39 */
40
41/*
42 * /dev/fd Filesystem
43 */
44
45#include <sys/param.h>
46#include <sys/systm.h>
47#include <sys/conf.h>
48#include <sys/dirent.h>
49#include <sys/filedesc.h>
50#include <sys/kernel.h> /* boottime */
51#include <sys/lock.h>
52#include <sys/malloc.h>
53#include <sys/file.h> /* Must come after sys/malloc.h */
54#include <sys/mount.h>
55#include <sys/namei.h>
56#include <sys/proc.h>
57#include <sys/socket.h>
58#include <sys/stat.h>
59#include <sys/vnode.h>
60
61#include <miscfs/fdesc/fdesc.h>
62
63#define FDL_WANT 0x01
64#define FDL_LOCKED 0x02
65static int fdcache_lock;
66
67static vop_t **fdesc_vnodeop_p;
68
69#define NFDCACHE 4
70#define FD_NHASH(ix) \
71 (&fdhashtbl[(ix) & fdhash])
72static LIST_HEAD(fdhashhead, fdescnode) *fdhashtbl;
73static u_long fdhash;
74
75static int fdesc_getattr __P((struct vop_getattr_args *ap));
76static int fdesc_inactive __P((struct vop_inactive_args *ap));
77static int fdesc_lookup __P((struct vop_lookup_args *ap));
78static int fdesc_open __P((struct vop_open_args *ap));
79static int fdesc_print __P((struct vop_print_args *ap));
80static int fdesc_readdir __P((struct vop_readdir_args *ap));
81static int fdesc_reclaim __P((struct vop_reclaim_args *ap));
82static int fdesc_poll __P((struct vop_poll_args *ap));
83static int fdesc_setattr __P((struct vop_setattr_args *ap));
84
85/*
86 * Initialise cache headers
87 */
88int
89fdesc_init(vfsp)
90 struct vfsconf *vfsp;
91{
92
93 fdhashtbl = hashinit(NFDCACHE, M_CACHE, &fdhash);
94 return (0);
95}
96
97int
98fdesc_allocvp(ftype, ix, mp, vpp, p)
99 fdntype ftype;
100 int ix;
101 struct mount *mp;
102 struct vnode **vpp;
103 struct proc *p;
104{
105 struct fdhashhead *fc;
106 struct fdescnode *fd;
107 int error = 0;
108
109 fc = FD_NHASH(ix);
110loop:
111 LIST_FOREACH(fd, fc, fd_hash) {
112 if (fd->fd_ix == ix && fd->fd_vnode->v_mount == mp) {
113 if (vget(fd->fd_vnode, 0, p))
114 goto loop;
115 *vpp = fd->fd_vnode;
116 return (error);
117 }
118 }
119
120 /*
121 * otherwise lock the array while we call getnewvnode
122 * since that can block.
123 */
124 if (fdcache_lock & FDL_LOCKED) {
125 fdcache_lock |= FDL_WANT;
126 (void) tsleep((caddr_t) &fdcache_lock, PINOD, "fdalvp", 0);
127 goto loop;
128 }
129 fdcache_lock |= FDL_LOCKED;
130
131 /*
132 * Do the MALLOC before the getnewvnode since doing so afterward
133 * might cause a bogus v_data pointer to get dereferenced
134 * elsewhere if MALLOC should block.
135 */
136 MALLOC(fd, struct fdescnode *, sizeof(struct fdescnode), M_TEMP, M_WAITOK);
137
138 error = getnewvnode(VT_FDESC, mp, fdesc_vnodeop_p, vpp);
139 if (error) {
140 FREE(fd, M_TEMP);
141 goto out;
142 }
143 (*vpp)->v_data = fd;
144 fd->fd_vnode = *vpp;
145 fd->fd_type = ftype;
146 fd->fd_fd = -1;
147 fd->fd_ix = ix;
148 LIST_INSERT_HEAD(fc, fd, fd_hash);
149
150out:
151 fdcache_lock &= ~FDL_LOCKED;
152
153 if (fdcache_lock & FDL_WANT) {
154 fdcache_lock &= ~FDL_WANT;
155 wakeup((caddr_t) &fdcache_lock);
156 }
157
158 return (error);
159}
160
161/*
162 * vp is the current namei directory
163 * ndp is the name to locate in that directory...
164 */
165static int
166fdesc_lookup(ap)
167 struct vop_lookup_args /* {
168 struct vnode * a_dvp;
169 struct vnode ** a_vpp;
170 struct componentname * a_cnp;
171 } */ *ap;
172{
173 struct vnode **vpp = ap->a_vpp;
174 struct vnode *dvp = ap->a_dvp;
175 struct componentname *cnp = ap->a_cnp;
176 char *pname = cnp->cn_nameptr;
177 struct proc *p = cnp->cn_proc;
178 int nlen = cnp->cn_namelen;
179 int nfiles = p->p_fd->fd_nfiles;
180 u_int fd;
181 int error;
182 struct vnode *fvp;
183
184 if (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME) {
185 error = EROFS;
186 goto bad;
187 }
188
189 VOP_UNLOCK(dvp, 0, p);
190 if (cnp->cn_namelen == 1 && *pname == '.') {
191 *vpp = dvp;
192 VREF(dvp);
193 vn_lock(dvp, LK_SHARED | LK_RETRY, p);
194 return (0);
195 }
196
197 if (VTOFDESC(dvp)->fd_type != Froot) {
198 error = ENOTDIR;
199 goto bad;
200 }
201
202 fd = 0;
203 /* the only time a leading 0 is acceptable is if it's "0" */
204 if (*pname == '0' && nlen != 1) {
205 error = ENOENT;
206 goto bad;
207 }
208 while (nlen--) {
209 if (*pname < '0' || *pname > '9') {
210 error = ENOENT;
211 goto bad;
212 }
213 fd = 10 * fd + *pname++ - '0';
214 }
215
216 if (fd >= nfiles || p->p_fd->fd_ofiles[fd] == NULL) {
217 error = EBADF;
218 goto bad;
219 }
220
221 error = fdesc_allocvp(Fdesc, FD_DESC+fd, dvp->v_mount, &fvp, p);
222 if (error)
223 goto bad;
224 VTOFDESC(fvp)->fd_fd = fd;
225 vn_lock(fvp, LK_SHARED | LK_RETRY, p);
226 *vpp = fvp;
227 return (0);
228
229bad:
230 vn_lock(dvp, LK_SHARED | LK_RETRY, p);
231 *vpp = NULL;
232 return (error);
233}
234
235static int
236fdesc_open(ap)
237 struct vop_open_args /* {
238 struct vnode *a_vp;
239 int a_mode;
240 struct ucred *a_cred;
241 struct proc *a_p;
242 } */ *ap;
243{
244 struct vnode *vp = ap->a_vp;
245
246 if (VTOFDESC(vp)->fd_type == Froot)
247 return (0);
248
249 /*
250 * XXX Kludge: set p->p_dupfd to contain the value of the the file
251 * descriptor being sought for duplication. The error return ensures
252 * that the vnode for this device will be released by vn_open. Open
253 * will detect this special error and take the actions in dupfdopen.
254 * Other callers of vn_open or VOP_OPEN will simply report the
255 * error.
256 */
257 ap->a_p->p_dupfd = VTOFDESC(vp)->fd_fd; /* XXX */
258 return (ENODEV);
259}
260
261static int
262fdesc_getattr(ap)
263 struct vop_getattr_args /* {
264 struct vnode *a_vp;
265 struct vattr *a_vap;
266 struct ucred *a_cred;
267 struct proc *a_p;
268 } */ *ap;
269{
270 struct vnode *vp = ap->a_vp;
271 struct vattr *vap = ap->a_vap;
272 struct filedesc *fdp = ap->a_p->p_fd;
273 struct file *fp;
274 struct stat stb;
275 u_int fd;
276 int error = 0;
277
278 switch (VTOFDESC(vp)->fd_type) {
279 case Froot:
280 VATTR_NULL(vap);
281
282 vap->va_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
283 vap->va_type = VDIR;
284 vap->va_nlink = 2;
285 vap->va_size = DEV_BSIZE;
286 vap->va_fileid = VTOFDESC(vp)->fd_ix;
287 vap->va_uid = 0;
288 vap->va_gid = 0;
289 vap->va_blocksize = DEV_BSIZE;
290 vap->va_atime.tv_sec = boottime.tv_sec;
291 vap->va_atime.tv_nsec = 0;
292 vap->va_mtime = vap->va_atime;
293 vap->va_ctime = vap->va_mtime;
294 vap->va_gen = 0;
295 vap->va_flags = 0;
296 vap->va_rdev = 0;
297 vap->va_bytes = 0;
298 break;
299
300 case Fdesc:
301 fd = VTOFDESC(vp)->fd_fd;
302
303 if (fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL)
304 return (EBADF);
305
306 bzero(&stb, sizeof(stb));
307 error = fo_stat(fp, &stb, ap->a_p);
308 if (error == 0) {
309 VATTR_NULL(vap);
310 vap->va_type = IFTOVT(stb.st_mode);
311 vap->va_mode = stb.st_mode;
312#define FDRX (VREAD|VEXEC)
313 if (vap->va_type == VDIR)
314 vap->va_mode &= ~((FDRX)|(FDRX>>3)|(FDRX>>6));
315#undef FDRX
316 vap->va_nlink = 1;
317 vap->va_flags = 0;
318 vap->va_bytes = stb.st_blocks * stb.st_blksize;
319 vap->va_fileid = VTOFDESC(vp)->fd_ix;
320 vap->va_size = stb.st_size;
321 vap->va_blocksize = stb.st_blksize;
322 vap->va_rdev = stb.st_rdev;
323
324 /*
325 * If no time data is provided, use the current time.
326 */
327 if (stb.st_atimespec.tv_sec == 0 &&
328 stb.st_atimespec.tv_nsec == 0)
329 nanotime(&stb.st_atimespec);
330
331 if (stb.st_ctimespec.tv_sec == 0 &&
332 stb.st_ctimespec.tv_nsec == 0)
333 nanotime(&stb.st_ctimespec);
334
335 if (stb.st_mtimespec.tv_sec == 0 &&
336 stb.st_mtimespec.tv_nsec == 0)
337 nanotime(&stb.st_mtimespec);
338
339 vap->va_atime = stb.st_atimespec;
340 vap->va_mtime = stb.st_mtimespec;
341 vap->va_ctime = stb.st_ctimespec;
342 vap->va_uid = stb.st_uid;
343 vap->va_gid = stb.st_gid;
344 }
345 break;
346
347 default:
348 panic("fdesc_getattr");
349 break;
350 }
351
352 if (error == 0)
353 vp->v_type = vap->va_type;
354 return (error);
355}
356
357static int
358fdesc_setattr(ap)
359 struct vop_setattr_args /* {
360 struct vnode *a_vp;
361 struct vattr *a_vap;
362 struct ucred *a_cred;
363 struct proc *a_p;
364 } */ *ap;
365{
366 struct vattr *vap = ap->a_vap;
367 struct file *fp;
368 unsigned fd;
369 int error;
370
371 /*
372 * Can't mess with the root vnode
373 */
374 if (VTOFDESC(ap->a_vp)->fd_type == Froot)
375 return (EACCES);
376
377 fd = VTOFDESC(ap->a_vp)->fd_fd;
378
379 /*
380 * Allow setattr where there is an underlying vnode.
381 */
382 error = getvnode(ap->a_p->p_fd, fd, &fp);
383 if (error) {
384 /*
385 * getvnode() returns EINVAL if the file descriptor is not
386 * backed by a vnode. Silently drop all changes except
387 * chflags(2) in this case.
388 */
389 if (error == EINVAL) {
390 if (vap->va_flags != VNOVAL)
391 error = EOPNOTSUPP;
392 else
393 error = 0;
394 }
395 return (error);
396 }
397 return (error);
398}
399
400#define UIO_MX 16
401
402static int
403fdesc_readdir(ap)
404 struct vop_readdir_args /* {
405 struct vnode *a_vp;
406 struct uio *a_uio;
407 struct ucred *a_cred;
408 int *a_eofflag;
409 u_long *a_cookies;
410 int a_ncookies;
411 } */ *ap;
412{
413 struct uio *uio = ap->a_uio;
414 struct filedesc *fdp;
415 struct dirent d;
416 struct dirent *dp = &d;
417 int error, i, off, fcnt;
418
419 /*
420 * We don't allow exporting fdesc mounts, and currently local
421 * requests do not need cookies.
422 */
423 if (ap->a_ncookies)
424 panic("fdesc_readdir: not hungry");
425
426 if (VTOFDESC(ap->a_vp)->fd_type != Froot)
427 panic("fdesc_readdir: not dir");
428
429 off = (int)uio->uio_offset;
430 if (off != uio->uio_offset || off < 0 || (u_int)off % UIO_MX != 0 ||
431 uio->uio_resid < UIO_MX)
432 return (EINVAL);
433 i = (u_int)off / UIO_MX;
434 fdp = uio->uio_procp->p_fd;
435 error = 0;
436
437 fcnt = i - 2; /* The first two nodes are `.' and `..' */
438
439 while (i < fdp->fd_nfiles + 2 && uio->uio_resid >= UIO_MX) {
440 switch (i) {
441 case 0: /* `.' */
442 case 1: /* `..' */
443 bzero((caddr_t)dp, UIO_MX);
444
445 dp->d_fileno = i + FD_ROOT;
446 dp->d_namlen = i + 1;
447 dp->d_reclen = UIO_MX;
448 bcopy("..", dp->d_name, dp->d_namlen);
449 dp->d_name[i + 1] = '\0';
450 dp->d_type = DT_DIR;
451 break;
452 default:
453 if (fdp->fd_ofiles[fcnt] == NULL)
454 goto done;
455
456 bzero((caddr_t) dp, UIO_MX);
457 dp->d_namlen = sprintf(dp->d_name, "%d", fcnt);
458 dp->d_reclen = UIO_MX;
459 dp->d_type = DT_UNKNOWN;
460 dp->d_fileno = i + FD_DESC;
461 break;
462 }
463 /*
464 * And ship to userland
465 */
466 error = uiomove((caddr_t) dp, UIO_MX, uio);
467 if (error)
468 break;
469 i++;
470 fcnt++;
471 }
472
473done:
474 uio->uio_offset = i * UIO_MX;
475 return (error);
476}
477
478static int
479fdesc_poll(ap)
480 struct vop_poll_args /* {
481 struct vnode *a_vp;
482 int a_events;
483 struct ucred *a_cred;
484 struct proc *a_p;
485 } */ *ap;
486{
487 return seltrue(0, ap->a_events, ap->a_p);
488}
489
490static int
491fdesc_inactive(ap)
492 struct vop_inactive_args /* {
493 struct vnode *a_vp;
494 struct proc *a_p;
495 } */ *ap;
496{
497 struct vnode *vp = ap->a_vp;
498
499 /*
500 * Clear out the v_type field to avoid
501 * nasty things happening in vgone().
502 */
503 VOP_UNLOCK(vp, 0, ap->a_p);
504 vp->v_type = VNON;
505 return (0);
506}
507
508static int
509fdesc_reclaim(ap)
510 struct vop_reclaim_args /* {
511 struct vnode *a_vp;
512 } */ *ap;
513{
514 struct vnode *vp = ap->a_vp;
515 struct fdescnode *fd = VTOFDESC(vp);
516
517 LIST_REMOVE(fd, fd_hash);
518 FREE(vp->v_data, M_TEMP);
519 vp->v_data = 0;
520
521 return (0);
522}
523
524/*
525 * Print out the contents of a /dev/fd vnode.
526 */
527/* ARGSUSED */
528static int
529fdesc_print(ap)
530 struct vop_print_args /* {
531 struct vnode *a_vp;
532 } */ *ap;
533{
534
535 printf("tag VT_NON, fdesc vnode\n");
536 return (0);
537}
538
539static struct vnodeopv_entry_desc fdesc_vnodeop_entries[] = {
540 { &vop_default_desc, (vop_t *) vop_defaultop },
541 { &vop_access_desc, (vop_t *) vop_null },
542 { &vop_getattr_desc, (vop_t *) fdesc_getattr },
543 { &vop_inactive_desc, (vop_t *) fdesc_inactive },
544 { &vop_lookup_desc, (vop_t *) fdesc_lookup },
545 { &vop_open_desc, (vop_t *) fdesc_open },
546 { &vop_pathconf_desc, (vop_t *) vop_stdpathconf },
547 { &vop_poll_desc, (vop_t *) fdesc_poll },
548 { &vop_print_desc, (vop_t *) fdesc_print },
549 { &vop_readdir_desc, (vop_t *) fdesc_readdir },
550 { &vop_reclaim_desc, (vop_t *) fdesc_reclaim },
551 { &vop_setattr_desc, (vop_t *) fdesc_setattr },
552 { NULL, NULL }
553};
554static struct vnodeopv_desc fdesc_vnodeop_opv_desc =
555 { &fdesc_vnodeop_p, fdesc_vnodeop_entries };
556
557VNODEOP_SET(fdesc_vnodeop_opv_desc);