FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_vnops.c
1 /*
2 * Copyright (c) 1982, 1986, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
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 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94
39 * $FreeBSD: src/sys/kern/vfs_vnops.c,v 1.26.2.4 1999/09/05 08:15:47 peter Exp $
40 */
41
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
45 #include <sys/file.h>
46 #include <sys/stat.h>
47 #include <sys/buf.h>
48 #include <sys/proc.h>
49 #include <sys/mount.h>
50 #include <sys/namei.h>
51 #include <sys/vnode.h>
52 #include <sys/ioctl.h>
53
54 #include <vm/vm.h>
55 #include <vm/vm_param.h>
56 #include <vm/vm_object.h>
57 #include <vm/vnode_pager.h>
58
59 static int vn_closefile __P((struct file *fp, struct proc *p));
60 static int vn_ioctl __P((struct file *fp, int com, caddr_t data,
61 struct proc *p));
62 static int vn_read __P((struct file *fp, struct uio *uio,
63 struct ucred *cred));
64 static int vn_select __P((struct file *fp, int which, struct proc *p));
65 static int vn_write __P((struct file *fp, struct uio *uio,
66 struct ucred *cred));
67
68 struct fileops vnops =
69 { vn_read, vn_write, vn_ioctl, vn_select, vn_closefile };
70
71 /*
72 * Common code for vnode open operations.
73 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
74 */
75 int
76 vn_open(ndp, fmode, cmode)
77 register struct nameidata *ndp;
78 int fmode, cmode;
79 {
80 register struct vnode *vp;
81 register struct proc *p = ndp->ni_cnd.cn_proc;
82 register struct ucred *cred = p->p_ucred;
83 struct vattr vat;
84 struct vattr *vap = &vat;
85 int error;
86
87 if (fmode & O_CREAT) {
88 ndp->ni_cnd.cn_nameiop = CREATE;
89 ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF;
90 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
91 ndp->ni_cnd.cn_flags |= FOLLOW;
92 error = namei(ndp);
93 if (error)
94 return (error);
95 if (ndp->ni_vp == NULL) {
96 VATTR_NULL(vap);
97 vap->va_type = VREG;
98 vap->va_mode = cmode;
99 LEASE_CHECK(ndp->ni_dvp, p, cred, LEASE_WRITE);
100 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
101 &ndp->ni_cnd, vap);
102 if (error)
103 return (error);
104 fmode &= ~O_TRUNC;
105 vp = ndp->ni_vp;
106 } else {
107 VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd);
108 if (ndp->ni_dvp == ndp->ni_vp)
109 vrele(ndp->ni_dvp);
110 else
111 vput(ndp->ni_dvp);
112 ndp->ni_dvp = NULL;
113 vp = ndp->ni_vp;
114 if (fmode & O_EXCL) {
115 error = EEXIST;
116 goto bad;
117 }
118 fmode &= ~O_CREAT;
119 }
120 } else {
121 ndp->ni_cnd.cn_nameiop = LOOKUP;
122 ndp->ni_cnd.cn_flags =
123 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF;
124 error = namei(ndp);
125 if (error)
126 return (error);
127 vp = ndp->ni_vp;
128 }
129 if (vp->v_type == VSOCK) {
130 error = EOPNOTSUPP;
131 goto bad;
132 }
133 if ((fmode & O_CREAT) == 0) {
134 if (fmode & FREAD) {
135 error = VOP_ACCESS(vp, VREAD, cred, p);
136 if (error)
137 goto bad;
138 }
139 if (fmode & (FWRITE | O_TRUNC)) {
140 if (vp->v_type == VDIR) {
141 error = EISDIR;
142 goto bad;
143 }
144 error = vn_writechk(vp);
145 if (error)
146 goto bad;
147 error = VOP_ACCESS(vp, VWRITE, cred, p);
148 if (error)
149 goto bad;
150 }
151 }
152 if (fmode & O_TRUNC) {
153 VOP_UNLOCK(vp); /* XXX */
154 LEASE_CHECK(vp, p, cred, LEASE_WRITE);
155 VOP_LOCK(vp); /* XXX */
156 VATTR_NULL(vap);
157 vap->va_size = 0;
158 error = VOP_SETATTR(vp, vap, cred, p);
159 if (error)
160 goto bad;
161 }
162 error = VOP_OPEN(vp, fmode, cred, p);
163 if (error)
164 goto bad;
165 /*
166 * Make sure that a VM object is created for VMIO support.
167 */
168 if (vp->v_type == VREG) {
169 if ((error = vfs_object_create(vp, p, cred, 1)) != 0)
170 goto bad;
171 }
172
173 if (fmode & FWRITE)
174 vp->v_writecount++;
175 return (0);
176 bad:
177 vput(vp);
178 return (error);
179 }
180
181 /*
182 * Check for write permissions on the specified vnode.
183 * The read-only status of the file system is checked.
184 * Also, prototype text segments cannot be written.
185 */
186 int
187 vn_writechk(vp)
188 register struct vnode *vp;
189 {
190
191 /*
192 * If there's shared text associated with
193 * the vnode, try to free it up once. If
194 * we fail, we can't allow writing.
195 */
196 if (vp->v_flag & VTEXT)
197 return (ETXTBSY);
198 return (0);
199 }
200
201 /*
202 * Vnode close call
203 */
204 int
205 vn_close(vp, flags, cred, p)
206 register struct vnode *vp;
207 int flags;
208 struct ucred *cred;
209 struct proc *p;
210 {
211 int error;
212
213 if (flags & FWRITE)
214 vp->v_writecount--;
215 error = VOP_CLOSE(vp, flags, cred, p);
216 vrele(vp);
217 return (error);
218 }
219
220 /*
221 * Package up an I/O request on a vnode into a uio and do it.
222 */
223 int
224 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p)
225 enum uio_rw rw;
226 struct vnode *vp;
227 caddr_t base;
228 int len;
229 off_t offset;
230 enum uio_seg segflg;
231 int ioflg;
232 struct ucred *cred;
233 int *aresid;
234 struct proc *p;
235 {
236 struct uio auio;
237 struct iovec aiov;
238 int error;
239
240 if ((ioflg & IO_NODELOCKED) == 0)
241 VOP_LOCK(vp);
242 auio.uio_iov = &aiov;
243 auio.uio_iovcnt = 1;
244 aiov.iov_base = base;
245 aiov.iov_len = len;
246 auio.uio_resid = len;
247 auio.uio_offset = offset;
248 auio.uio_segflg = segflg;
249 auio.uio_rw = rw;
250 auio.uio_procp = p;
251 if (rw == UIO_READ) {
252 error = VOP_READ(vp, &auio, ioflg, cred);
253 } else {
254 error = VOP_WRITE(vp, &auio, ioflg, cred);
255 }
256 if (aresid)
257 *aresid = auio.uio_resid;
258 else
259 if (auio.uio_resid && error == 0)
260 error = EIO;
261 if ((ioflg & IO_NODELOCKED) == 0)
262 VOP_UNLOCK(vp);
263 return (error);
264 }
265
266 /*
267 * File table vnode read routine.
268 */
269 static int
270 vn_read(fp, uio, cred)
271 struct file *fp;
272 struct uio *uio;
273 struct ucred *cred;
274 {
275 register struct vnode *vp = (struct vnode *)fp->f_data;
276 int count, error;
277
278 LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_READ);
279 VOP_LOCK(vp);
280 uio->uio_offset = fp->f_offset;
281 count = uio->uio_resid;
282 error = VOP_READ(vp, uio, (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0,
283 cred);
284 fp->f_offset += count - uio->uio_resid;
285 VOP_UNLOCK(vp);
286 return (error);
287 }
288
289 /*
290 * File table vnode write routine.
291 */
292 static int
293 vn_write(fp, uio, cred)
294 struct file *fp;
295 struct uio *uio;
296 struct ucred *cred;
297 {
298 register struct vnode *vp = (struct vnode *)fp->f_data;
299 int count, error, ioflag = 0;
300
301 if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
302 ioflag |= IO_APPEND;
303 if (fp->f_flag & FNONBLOCK)
304 ioflag |= IO_NDELAY;
305 LEASE_CHECK(vp, uio->uio_procp, cred, LEASE_WRITE);
306 VOP_LOCK(vp);
307 uio->uio_offset = fp->f_offset;
308 count = uio->uio_resid;
309 error = VOP_WRITE(vp, uio, ioflag, cred);
310 if (ioflag & IO_APPEND)
311 fp->f_offset = uio->uio_offset;
312 else
313 fp->f_offset += count - uio->uio_resid;
314 VOP_UNLOCK(vp);
315 return (error);
316 }
317
318 /*
319 * File table vnode stat routine.
320 */
321 int
322 vn_stat(vp, sb, p)
323 struct vnode *vp;
324 register struct stat *sb;
325 struct proc *p;
326 {
327 struct vattr vattr;
328 register struct vattr *vap;
329 int error;
330 u_short mode;
331
332 vap = &vattr;
333 error = VOP_GETATTR(vp, vap, p->p_ucred, p);
334 if (error)
335 return (error);
336 /*
337 * Copy from vattr table
338 */
339 sb->st_dev = vap->va_fsid;
340 sb->st_ino = vap->va_fileid;
341 mode = vap->va_mode;
342 switch (vp->v_type) {
343 case VREG:
344 mode |= S_IFREG;
345 break;
346 case VDIR:
347 mode |= S_IFDIR;
348 break;
349 case VBLK:
350 mode |= S_IFBLK;
351 break;
352 case VCHR:
353 mode |= S_IFCHR;
354 break;
355 case VLNK:
356 mode |= S_IFLNK;
357 break;
358 case VSOCK:
359 mode |= S_IFSOCK;
360 break;
361 case VFIFO:
362 mode |= S_IFIFO;
363 break;
364 default:
365 return (EBADF);
366 };
367 sb->st_mode = mode;
368 sb->st_nlink = vap->va_nlink;
369 sb->st_uid = vap->va_uid;
370 sb->st_gid = vap->va_gid;
371 sb->st_rdev = vap->va_rdev;
372 sb->st_size = vap->va_size;
373 sb->st_atimespec = vap->va_atime;
374 sb->st_mtimespec= vap->va_mtime;
375 sb->st_ctimespec = vap->va_ctime;
376 sb->st_blksize = vap->va_blocksize;
377 sb->st_flags = vap->va_flags;
378 if (p->p_ucred->cr_uid !=0 )
379 sb->st_gen = 0;
380 else
381 sb->st_gen = vap->va_gen;
382
383 #if (S_BLKSIZE == 512)
384 /* Optimize this case */
385 sb->st_blocks = vap->va_bytes >> 9;
386 #else
387 sb->st_blocks = vap->va_bytes / S_BLKSIZE;
388 #endif
389 return (0);
390 }
391
392 /*
393 * File table vnode ioctl routine.
394 */
395 static int
396 vn_ioctl(fp, com, data, p)
397 struct file *fp;
398 int com;
399 caddr_t data;
400 struct proc *p;
401 {
402 register struct vnode *vp = ((struct vnode *)fp->f_data);
403 struct vattr vattr;
404 int error;
405
406 switch (vp->v_type) {
407
408 case VREG:
409 case VDIR:
410 if (com == FIONREAD) {
411 error = VOP_GETATTR(vp, &vattr, p->p_ucred, p);
412 if (error)
413 return (error);
414 *(int *)data = vattr.va_size - fp->f_offset;
415 return (0);
416 }
417 if (com == FIONBIO || com == FIOASYNC) /* XXX */
418 return (0); /* XXX */
419 /* fall into ... */
420
421 default:
422 return (ENOTTY);
423
424 case VFIFO:
425 case VCHR:
426 case VBLK:
427 error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p);
428 if (error == 0 && com == TIOCSCTTY) {
429
430 /* Do nothing if reassigning same control tty */
431 if (p->p_session->s_ttyvp == vp)
432 return (0);
433
434 /* Get rid of reference to old control tty */
435 if (p->p_session->s_ttyvp)
436 vrele(p->p_session->s_ttyvp);
437
438 p->p_session->s_ttyvp = vp;
439 VREF(vp);
440 }
441 return (error);
442 }
443 }
444
445 /*
446 * File table vnode select routine.
447 */
448 static int
449 vn_select(fp, which, p)
450 struct file *fp;
451 int which;
452 struct proc *p;
453 {
454
455 return (VOP_SELECT(((struct vnode *)fp->f_data), which, fp->f_flag,
456 fp->f_cred, p));
457 }
458
459 /*
460 * File table vnode close routine.
461 */
462 static int
463 vn_closefile(fp, p)
464 struct file *fp;
465 struct proc *p;
466 {
467
468 return (vn_close(((struct vnode *)fp->f_data), fp->f_flag,
469 fp->f_cred, p));
470 }
Cache object: 5034628c3495cec935394cae9af5d0b6
|