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 * 4. 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 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39
40 #include "opt_mac.h"
41
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/fcntl.h>
45 #include <sys/file.h>
46 #include <sys/kdb.h>
47 #include <sys/stat.h>
48 #include <sys/priv.h>
49 #include <sys/proc.h>
50 #include <sys/limits.h>
51 #include <sys/lock.h>
52 #include <sys/mount.h>
53 #include <sys/mutex.h>
54 #include <sys/namei.h>
55 #include <sys/vnode.h>
56 #include <sys/bio.h>
57 #include <sys/buf.h>
58 #include <sys/filio.h>
59 #include <sys/sx.h>
60 #include <sys/ttycom.h>
61 #include <sys/conf.h>
62 #include <sys/syslog.h>
63 #include <sys/unistd.h>
64
65 #include <security/mac/mac_framework.h>
66
67 static fo_rdwr_t vn_read;
68 static fo_rdwr_t vn_write;
69 static fo_ioctl_t vn_ioctl;
70 static fo_poll_t vn_poll;
71 static fo_kqfilter_t vn_kqfilter;
72 static fo_stat_t vn_statfile;
73 static fo_close_t vn_closefile;
74
75 struct fileops vnops = {
76 .fo_read = vn_read,
77 .fo_write = vn_write,
78 .fo_ioctl = vn_ioctl,
79 .fo_poll = vn_poll,
80 .fo_kqfilter = vn_kqfilter,
81 .fo_stat = vn_statfile,
82 .fo_close = vn_closefile,
83 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE
84 };
85
86 int
87 vn_open(ndp, flagp, cmode, fp)
88 struct nameidata *ndp;
89 int *flagp, cmode;
90 struct file *fp;
91 {
92 struct thread *td = ndp->ni_cnd.cn_thread;
93
94 return (vn_open_cred(ndp, flagp, cmode, td->td_ucred, fp));
95 }
96
97 /*
98 * Common code for vnode open operations.
99 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
100 *
101 * Note that this does NOT free nameidata for the successful case,
102 * due to the NDINIT being done elsewhere.
103 */
104 int
105 vn_open_cred(ndp, flagp, cmode, cred, fp)
106 struct nameidata *ndp;
107 int *flagp, cmode;
108 struct ucred *cred;
109 struct file *fp;
110 {
111 struct vnode *vp;
112 struct mount *mp;
113 struct thread *td = ndp->ni_cnd.cn_thread;
114 struct vattr vat;
115 struct vattr *vap = &vat;
116 int mode, fmode, error;
117 int vfslocked, mpsafe;
118
119 mpsafe = ndp->ni_cnd.cn_flags & MPSAFE;
120 restart:
121 vfslocked = 0;
122 fmode = *flagp;
123 if (fmode & O_CREAT) {
124 ndp->ni_cnd.cn_nameiop = CREATE;
125 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF |
126 MPSAFE | AUDITVNODE1;
127 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
128 ndp->ni_cnd.cn_flags |= FOLLOW;
129 bwillwrite();
130 if ((error = namei(ndp)) != 0)
131 return (error);
132 vfslocked = NDHASGIANT(ndp);
133 if (!mpsafe)
134 ndp->ni_cnd.cn_flags &= ~MPSAFE;
135 if (ndp->ni_vp == NULL) {
136 VATTR_NULL(vap);
137 vap->va_type = VREG;
138 vap->va_mode = cmode;
139 if (fmode & O_EXCL)
140 vap->va_vaflags |= VA_EXCLUSIVE;
141 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) {
142 NDFREE(ndp, NDF_ONLY_PNBUF);
143 vput(ndp->ni_dvp);
144 VFS_UNLOCK_GIANT(vfslocked);
145 if ((error = vn_start_write(NULL, &mp,
146 V_XSLEEP | PCATCH)) != 0)
147 return (error);
148 goto restart;
149 }
150 #ifdef MAC
151 error = mac_check_vnode_create(cred, ndp->ni_dvp,
152 &ndp->ni_cnd, vap);
153 if (error == 0) {
154 #endif
155 VOP_LEASE(ndp->ni_dvp, td, cred, LEASE_WRITE);
156 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
157 &ndp->ni_cnd, vap);
158 #ifdef MAC
159 }
160 #endif
161 vput(ndp->ni_dvp);
162 vn_finished_write(mp);
163 if (error) {
164 VFS_UNLOCK_GIANT(vfslocked);
165 NDFREE(ndp, NDF_ONLY_PNBUF);
166 return (error);
167 }
168 fmode &= ~O_TRUNC;
169 vp = ndp->ni_vp;
170 } else {
171 if (ndp->ni_dvp == ndp->ni_vp)
172 vrele(ndp->ni_dvp);
173 else
174 vput(ndp->ni_dvp);
175 ndp->ni_dvp = NULL;
176 vp = ndp->ni_vp;
177 if (fmode & O_EXCL) {
178 error = EEXIST;
179 goto bad;
180 }
181 fmode &= ~O_CREAT;
182 }
183 } else {
184 ndp->ni_cnd.cn_nameiop = LOOKUP;
185 ndp->ni_cnd.cn_flags = ISOPEN |
186 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) |
187 LOCKLEAF | MPSAFE | AUDITVNODE1;
188 if ((error = namei(ndp)) != 0)
189 return (error);
190 if (!mpsafe)
191 ndp->ni_cnd.cn_flags &= ~MPSAFE;
192 vfslocked = NDHASGIANT(ndp);
193 vp = ndp->ni_vp;
194 }
195 if (vp->v_type == VLNK) {
196 error = EMLINK;
197 goto bad;
198 }
199 if (vp->v_type == VSOCK) {
200 error = EOPNOTSUPP;
201 goto bad;
202 }
203 mode = 0;
204 if (fmode & (FWRITE | O_TRUNC)) {
205 if (vp->v_type == VDIR) {
206 error = EISDIR;
207 goto bad;
208 }
209 mode |= VWRITE;
210 }
211 if (fmode & FREAD)
212 mode |= VREAD;
213 if (fmode & O_APPEND)
214 mode |= VAPPEND;
215 #ifdef MAC
216 error = mac_check_vnode_open(cred, vp, mode);
217 if (error)
218 goto bad;
219 #endif
220 if ((fmode & O_CREAT) == 0) {
221 if (mode & VWRITE) {
222 error = vn_writechk(vp);
223 if (error)
224 goto bad;
225 }
226 if (mode) {
227 error = VOP_ACCESS(vp, mode, cred, td);
228 if (error)
229 goto bad;
230 }
231 }
232 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0)
233 goto bad;
234
235 if (fmode & FWRITE)
236 vp->v_writecount++;
237 *flagp = fmode;
238 ASSERT_VOP_ELOCKED(vp, "vn_open_cred");
239 if (!mpsafe)
240 VFS_UNLOCK_GIANT(vfslocked);
241 return (0);
242 bad:
243 NDFREE(ndp, NDF_ONLY_PNBUF);
244 vput(vp);
245 VFS_UNLOCK_GIANT(vfslocked);
246 *flagp = fmode;
247 ndp->ni_vp = NULL;
248 return (error);
249 }
250
251 /*
252 * Check for write permissions on the specified vnode.
253 * Prototype text segments cannot be written.
254 */
255 int
256 vn_writechk(vp)
257 register struct vnode *vp;
258 {
259
260 ASSERT_VOP_LOCKED(vp, "vn_writechk");
261 /*
262 * If there's shared text associated with
263 * the vnode, try to free it up once. If
264 * we fail, we can't allow writing.
265 */
266 if (vp->v_vflag & VV_TEXT)
267 return (ETXTBSY);
268
269 return (0);
270 }
271
272 /*
273 * Vnode close call
274 */
275 int
276 vn_close(vp, flags, file_cred, td)
277 register struct vnode *vp;
278 int flags;
279 struct ucred *file_cred;
280 struct thread *td;
281 {
282 struct mount *mp;
283 int error;
284
285 VFS_ASSERT_GIANT(vp->v_mount);
286
287 vn_start_write(vp, &mp, V_WAIT);
288 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
289 if (flags & FWRITE) {
290 VNASSERT(vp->v_writecount > 0, vp,
291 ("vn_close: negative writecount"));
292 vp->v_writecount--;
293 }
294 error = VOP_CLOSE(vp, flags, file_cred, td);
295 vput(vp);
296 vn_finished_write(mp);
297 return (error);
298 }
299
300 /*
301 * Sequential heuristic - detect sequential operation
302 */
303 static __inline
304 int
305 sequential_heuristic(struct uio *uio, struct file *fp)
306 {
307
308 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) ||
309 uio->uio_offset == fp->f_nextoff) {
310 /*
311 * XXX we assume that the filesystem block size is
312 * the default. Not true, but still gives us a pretty
313 * good indicator of how sequential the read operations
314 * are.
315 */
316 fp->f_seqcount += (uio->uio_resid + BKVASIZE - 1) / BKVASIZE;
317 if (fp->f_seqcount > IO_SEQMAX)
318 fp->f_seqcount = IO_SEQMAX;
319 return(fp->f_seqcount << IO_SEQSHIFT);
320 }
321
322 /*
323 * Not sequential, quick draw-down of seqcount
324 */
325 if (fp->f_seqcount > 1)
326 fp->f_seqcount = 1;
327 else
328 fp->f_seqcount = 0;
329 return(0);
330 }
331
332 /*
333 * Package up an I/O request on a vnode into a uio and do it.
334 */
335 int
336 vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, active_cred, file_cred,
337 aresid, td)
338 enum uio_rw rw;
339 struct vnode *vp;
340 void *base;
341 int len;
342 off_t offset;
343 enum uio_seg segflg;
344 int ioflg;
345 struct ucred *active_cred;
346 struct ucred *file_cred;
347 int *aresid;
348 struct thread *td;
349 {
350 struct uio auio;
351 struct iovec aiov;
352 struct mount *mp;
353 struct ucred *cred;
354 int error;
355
356 VFS_ASSERT_GIANT(vp->v_mount);
357
358 if ((ioflg & IO_NODELOCKED) == 0) {
359 mp = NULL;
360 if (rw == UIO_WRITE) {
361 if (vp->v_type != VCHR &&
362 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH))
363 != 0)
364 return (error);
365 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
366 } else {
367 /*
368 * XXX This should be LK_SHARED but I don't trust VFS
369 * enough to leave it like that until it has been
370 * reviewed further.
371 */
372 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
373 }
374
375 }
376 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
377 auio.uio_iov = &aiov;
378 auio.uio_iovcnt = 1;
379 aiov.iov_base = base;
380 aiov.iov_len = len;
381 auio.uio_resid = len;
382 auio.uio_offset = offset;
383 auio.uio_segflg = segflg;
384 auio.uio_rw = rw;
385 auio.uio_td = td;
386 error = 0;
387 #ifdef MAC
388 if ((ioflg & IO_NOMACCHECK) == 0) {
389 if (rw == UIO_READ)
390 error = mac_check_vnode_read(active_cred, file_cred,
391 vp);
392 else
393 error = mac_check_vnode_write(active_cred, file_cred,
394 vp);
395 }
396 #endif
397 if (error == 0) {
398 if (file_cred)
399 cred = file_cred;
400 else
401 cred = active_cred;
402 if (rw == UIO_READ)
403 error = VOP_READ(vp, &auio, ioflg, cred);
404 else
405 error = VOP_WRITE(vp, &auio, ioflg, cred);
406 }
407 if (aresid)
408 *aresid = auio.uio_resid;
409 else
410 if (auio.uio_resid && error == 0)
411 error = EIO;
412 if ((ioflg & IO_NODELOCKED) == 0) {
413 if (rw == UIO_WRITE && vp->v_type != VCHR)
414 vn_finished_write(mp);
415 VOP_UNLOCK(vp, 0, td);
416 }
417 return (error);
418 }
419
420 /*
421 * Package up an I/O request on a vnode into a uio and do it. The I/O
422 * request is split up into smaller chunks and we try to avoid saturating
423 * the buffer cache while potentially holding a vnode locked, so we
424 * check bwillwrite() before calling vn_rdwr(). We also call uio_yield()
425 * to give other processes a chance to lock the vnode (either other processes
426 * core'ing the same binary, or unrelated processes scanning the directory).
427 */
428 int
429 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred,
430 file_cred, aresid, td)
431 enum uio_rw rw;
432 struct vnode *vp;
433 void *base;
434 size_t len;
435 off_t offset;
436 enum uio_seg segflg;
437 int ioflg;
438 struct ucred *active_cred;
439 struct ucred *file_cred;
440 size_t *aresid;
441 struct thread *td;
442 {
443 int error = 0;
444 int iaresid;
445
446 VFS_ASSERT_GIANT(vp->v_mount);
447
448 do {
449 int chunk;
450
451 /*
452 * Force `offset' to a multiple of MAXBSIZE except possibly
453 * for the first chunk, so that filesystems only need to
454 * write full blocks except possibly for the first and last
455 * chunks.
456 */
457 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE;
458
459 if (chunk > len)
460 chunk = len;
461 if (rw != UIO_READ && vp->v_type == VREG)
462 bwillwrite();
463 iaresid = 0;
464 error = vn_rdwr(rw, vp, base, chunk, offset, segflg,
465 ioflg, active_cred, file_cred, &iaresid, td);
466 len -= chunk; /* aresid calc already includes length */
467 if (error)
468 break;
469 offset += chunk;
470 base = (char *)base + chunk;
471 uio_yield();
472 } while (len);
473 if (aresid)
474 *aresid = len + iaresid;
475 return (error);
476 }
477
478 /*
479 * File table vnode read routine.
480 */
481 static int
482 vn_read(fp, uio, active_cred, flags, td)
483 struct file *fp;
484 struct uio *uio;
485 struct ucred *active_cred;
486 struct thread *td;
487 int flags;
488 {
489 struct vnode *vp;
490 int error, ioflag;
491 int vfslocked;
492
493 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
494 uio->uio_td, td));
495 vp = fp->f_vnode;
496 ioflag = 0;
497 if (fp->f_flag & FNONBLOCK)
498 ioflag |= IO_NDELAY;
499 if (fp->f_flag & O_DIRECT)
500 ioflag |= IO_DIRECT;
501 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
502 VOP_LEASE(vp, td, fp->f_cred, LEASE_READ);
503 /*
504 * According to McKusick the vn lock was protecting f_offset here.
505 * It is now protected by the FOFFSET_LOCKED flag.
506 */
507 if ((flags & FOF_OFFSET) == 0) {
508 FILE_LOCK(fp);
509 while(fp->f_vnread_flags & FOFFSET_LOCKED) {
510 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING;
511 msleep(&fp->f_vnread_flags,fp->f_mtxp,PUSER -1,"vnread offlock",0);
512 }
513 fp->f_vnread_flags |= FOFFSET_LOCKED;
514 FILE_UNLOCK(fp);
515 vn_lock(vp, LK_SHARED | LK_RETRY, td);
516 uio->uio_offset = fp->f_offset;
517 } else
518 vn_lock(vp, LK_SHARED | LK_RETRY, td);
519
520 ioflag |= sequential_heuristic(uio, fp);
521
522 #ifdef MAC
523 error = mac_check_vnode_read(active_cred, fp->f_cred, vp);
524 if (error == 0)
525 #endif
526 error = VOP_READ(vp, uio, ioflag, fp->f_cred);
527 if ((flags & FOF_OFFSET) == 0) {
528 fp->f_offset = uio->uio_offset;
529 FILE_LOCK(fp);
530 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING)
531 wakeup(&fp->f_vnread_flags);
532 fp->f_vnread_flags = 0;
533 FILE_UNLOCK(fp);
534 }
535 fp->f_nextoff = uio->uio_offset;
536 VOP_UNLOCK(vp, 0, td);
537 VFS_UNLOCK_GIANT(vfslocked);
538 return (error);
539 }
540
541 /*
542 * File table vnode write routine.
543 */
544 static int
545 vn_write(fp, uio, active_cred, flags, td)
546 struct file *fp;
547 struct uio *uio;
548 struct ucred *active_cred;
549 struct thread *td;
550 int flags;
551 {
552 struct vnode *vp;
553 struct mount *mp;
554 int error, ioflag;
555 int vfslocked;
556
557 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
558 uio->uio_td, td));
559 vp = fp->f_vnode;
560 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
561 if (vp->v_type == VREG)
562 bwillwrite();
563 ioflag = IO_UNIT;
564 if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
565 ioflag |= IO_APPEND;
566 if (fp->f_flag & FNONBLOCK)
567 ioflag |= IO_NDELAY;
568 if (fp->f_flag & O_DIRECT)
569 ioflag |= IO_DIRECT;
570 if ((fp->f_flag & O_FSYNC) ||
571 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
572 ioflag |= IO_SYNC;
573 mp = NULL;
574 if (vp->v_type != VCHR &&
575 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
576 goto unlock;
577 VOP_LEASE(vp, td, fp->f_cred, LEASE_WRITE);
578 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
579 if ((flags & FOF_OFFSET) == 0)
580 uio->uio_offset = fp->f_offset;
581 ioflag |= sequential_heuristic(uio, fp);
582 #ifdef MAC
583 error = mac_check_vnode_write(active_cred, fp->f_cred, vp);
584 if (error == 0)
585 #endif
586 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred);
587 if ((flags & FOF_OFFSET) == 0)
588 fp->f_offset = uio->uio_offset;
589 fp->f_nextoff = uio->uio_offset;
590 VOP_UNLOCK(vp, 0, td);
591 if (vp->v_type != VCHR)
592 vn_finished_write(mp);
593 unlock:
594 VFS_UNLOCK_GIANT(vfslocked);
595 return (error);
596 }
597
598 /*
599 * File table vnode stat routine.
600 */
601 static int
602 vn_statfile(fp, sb, active_cred, td)
603 struct file *fp;
604 struct stat *sb;
605 struct ucred *active_cred;
606 struct thread *td;
607 {
608 struct vnode *vp = fp->f_vnode;
609 int vfslocked;
610 int error;
611
612 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
613 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
614 error = vn_stat(vp, sb, active_cred, fp->f_cred, td);
615 VOP_UNLOCK(vp, 0, td);
616 VFS_UNLOCK_GIANT(vfslocked);
617
618 return (error);
619 }
620
621 /*
622 * Stat a vnode; implementation for the stat syscall
623 */
624 int
625 vn_stat(vp, sb, active_cred, file_cred, td)
626 struct vnode *vp;
627 register struct stat *sb;
628 struct ucred *active_cred;
629 struct ucred *file_cred;
630 struct thread *td;
631 {
632 struct vattr vattr;
633 register struct vattr *vap;
634 int error;
635 u_short mode;
636
637 #ifdef MAC
638 error = mac_check_vnode_stat(active_cred, file_cred, vp);
639 if (error)
640 return (error);
641 #endif
642
643 vap = &vattr;
644 error = VOP_GETATTR(vp, vap, active_cred, td);
645 if (error)
646 return (error);
647
648 /*
649 * Zero the spare stat fields
650 */
651 bzero(sb, sizeof *sb);
652
653 /*
654 * Copy from vattr table
655 */
656 if (vap->va_fsid != VNOVAL)
657 sb->st_dev = vap->va_fsid;
658 else
659 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0];
660 sb->st_ino = vap->va_fileid;
661 mode = vap->va_mode;
662 switch (vap->va_type) {
663 case VREG:
664 mode |= S_IFREG;
665 break;
666 case VDIR:
667 mode |= S_IFDIR;
668 break;
669 case VBLK:
670 mode |= S_IFBLK;
671 break;
672 case VCHR:
673 mode |= S_IFCHR;
674 break;
675 case VLNK:
676 mode |= S_IFLNK;
677 /* This is a cosmetic change, symlinks do not have a mode. */
678 if (vp->v_mount->mnt_flag & MNT_NOSYMFOLLOW)
679 sb->st_mode &= ~ACCESSPERMS; /* 0000 */
680 else
681 sb->st_mode |= ACCESSPERMS; /* 0777 */
682 break;
683 case VSOCK:
684 mode |= S_IFSOCK;
685 break;
686 case VFIFO:
687 mode |= S_IFIFO;
688 break;
689 default:
690 return (EBADF);
691 };
692 sb->st_mode = mode;
693 sb->st_nlink = vap->va_nlink;
694 sb->st_uid = vap->va_uid;
695 sb->st_gid = vap->va_gid;
696 sb->st_rdev = vap->va_rdev;
697 if (vap->va_size > OFF_MAX)
698 return (EOVERFLOW);
699 sb->st_size = vap->va_size;
700 sb->st_atimespec = vap->va_atime;
701 sb->st_mtimespec = vap->va_mtime;
702 sb->st_ctimespec = vap->va_ctime;
703 sb->st_birthtimespec = vap->va_birthtime;
704
705 /*
706 * According to www.opengroup.org, the meaning of st_blksize is
707 * "a filesystem-specific preferred I/O block size for this
708 * object. In some filesystem types, this may vary from file
709 * to file"
710 * Default to PAGE_SIZE after much discussion.
711 * XXX: min(PAGE_SIZE, vp->v_bufobj.bo_bsize) may be more correct.
712 */
713
714 sb->st_blksize = PAGE_SIZE;
715
716 sb->st_flags = vap->va_flags;
717 if (priv_check(td, PRIV_VFS_GENERATION))
718 sb->st_gen = 0;
719 else
720 sb->st_gen = vap->va_gen;
721
722 sb->st_blocks = vap->va_bytes / S_BLKSIZE;
723 return (0);
724 }
725
726 /*
727 * File table vnode ioctl routine.
728 */
729 static int
730 vn_ioctl(fp, com, data, active_cred, td)
731 struct file *fp;
732 u_long com;
733 void *data;
734 struct ucred *active_cred;
735 struct thread *td;
736 {
737 struct vnode *vp = fp->f_vnode;
738 struct vattr vattr;
739 int vfslocked;
740 int error;
741
742 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
743 error = ENOTTY;
744 switch (vp->v_type) {
745 case VREG:
746 case VDIR:
747 if (com == FIONREAD) {
748 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
749 error = VOP_GETATTR(vp, &vattr, active_cred, td);
750 VOP_UNLOCK(vp, 0, td);
751 if (!error)
752 *(int *)data = vattr.va_size - fp->f_offset;
753 }
754 if (com == FIONBIO || com == FIOASYNC) /* XXX */
755 error = 0;
756 else
757 error = VOP_IOCTL(vp, com, data, fp->f_flag,
758 active_cred, td);
759 break;
760
761 default:
762 break;
763 }
764 VFS_UNLOCK_GIANT(vfslocked);
765 return (error);
766 }
767
768 /*
769 * File table vnode poll routine.
770 */
771 static int
772 vn_poll(fp, events, active_cred, td)
773 struct file *fp;
774 int events;
775 struct ucred *active_cred;
776 struct thread *td;
777 {
778 struct vnode *vp;
779 int vfslocked;
780 int error;
781
782 vp = fp->f_vnode;
783 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
784 #ifdef MAC
785 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
786 error = mac_check_vnode_poll(active_cred, fp->f_cred, vp);
787 VOP_UNLOCK(vp, 0, td);
788 if (!error)
789 #endif
790
791 error = VOP_POLL(vp, events, fp->f_cred, td);
792 VFS_UNLOCK_GIANT(vfslocked);
793 return (error);
794 }
795
796 /*
797 * Check that the vnode is still valid, and if so
798 * acquire requested lock.
799 */
800 int
801 _vn_lock(struct vnode *vp, int flags, struct thread *td, char *file, int line)
802 {
803 int error;
804
805 do {
806 if ((flags & LK_INTERLOCK) == 0)
807 VI_LOCK(vp);
808 if ((flags & LK_NOWAIT || (flags & LK_TYPE_MASK) == 0) &&
809 vp->v_iflag & VI_DOOMED) {
810 VI_UNLOCK(vp);
811 return (ENOENT);
812 }
813 /*
814 * Just polling to check validity.
815 */
816 if ((flags & LK_TYPE_MASK) == 0) {
817 VI_UNLOCK(vp);
818 return (0);
819 }
820 /*
821 * lockmgr drops interlock before it will return for
822 * any reason. So force the code above to relock it.
823 */
824 error = VOP_LOCK1(vp, flags | LK_INTERLOCK, td, file, line);
825 flags &= ~LK_INTERLOCK;
826 KASSERT((flags & LK_RETRY) == 0 || error == 0,
827 ("LK_RETRY set with incompatible flags %d\n", flags));
828 /*
829 * Callers specify LK_RETRY if they wish to get dead vnodes.
830 * If RETRY is not set, we return ENOENT instead.
831 */
832 if (error == 0 && vp->v_iflag & VI_DOOMED &&
833 (flags & LK_RETRY) == 0) {
834 VOP_UNLOCK(vp, 0, td);
835 error = ENOENT;
836 break;
837 }
838 } while (flags & LK_RETRY && error != 0);
839 return (error);
840 }
841
842 /*
843 * File table vnode close routine.
844 */
845 static int
846 vn_closefile(fp, td)
847 struct file *fp;
848 struct thread *td;
849 {
850 struct vnode *vp;
851 struct flock lf;
852 int vfslocked;
853 int error;
854
855 vp = fp->f_vnode;
856
857 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
858 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) {
859 lf.l_whence = SEEK_SET;
860 lf.l_start = 0;
861 lf.l_len = 0;
862 lf.l_type = F_UNLCK;
863 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK);
864 }
865
866 fp->f_ops = &badfileops;
867
868 error = vn_close(vp, fp->f_flag, fp->f_cred, td);
869 VFS_UNLOCK_GIANT(vfslocked);
870 return (error);
871 }
872
873 /*
874 * Preparing to start a filesystem write operation. If the operation is
875 * permitted, then we bump the count of operations in progress and
876 * proceed. If a suspend request is in progress, we wait until the
877 * suspension is over, and then proceed.
878 */
879 int
880 vn_start_write(vp, mpp, flags)
881 struct vnode *vp;
882 struct mount **mpp;
883 int flags;
884 {
885 struct mount *mp;
886 int error;
887
888 error = 0;
889 /*
890 * If a vnode is provided, get and return the mount point that
891 * to which it will write.
892 */
893 if (vp != NULL) {
894 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
895 *mpp = NULL;
896 if (error != EOPNOTSUPP)
897 return (error);
898 return (0);
899 }
900 }
901 if ((mp = *mpp) == NULL)
902 return (0);
903 MNT_ILOCK(mp);
904 if (vp == NULL)
905 MNT_REF(mp);
906 /*
907 * Check on status of suspension.
908 */
909 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
910 if (flags & V_NOWAIT) {
911 error = EWOULDBLOCK;
912 goto unlock;
913 }
914 error = msleep(&mp->mnt_flag, MNT_MTX(mp),
915 (PUSER - 1) | (flags & PCATCH), "suspfs", 0);
916 if (error)
917 goto unlock;
918 }
919 if (flags & V_XSLEEP)
920 goto unlock;
921 mp->mnt_writeopcount++;
922 unlock:
923 MNT_REL(mp);
924 MNT_IUNLOCK(mp);
925 return (error);
926 }
927
928 /*
929 * Secondary suspension. Used by operations such as vop_inactive
930 * routines that are needed by the higher level functions. These
931 * are allowed to proceed until all the higher level functions have
932 * completed (indicated by mnt_writeopcount dropping to zero). At that
933 * time, these operations are halted until the suspension is over.
934 */
935 int
936 vn_write_suspend_wait(vp, mp, flags)
937 struct vnode *vp;
938 struct mount *mp;
939 int flags;
940 {
941 int error;
942
943 if (vp != NULL) {
944 if ((error = VOP_GETWRITEMOUNT(vp, &mp)) != 0) {
945 if (error != EOPNOTSUPP)
946 return (error);
947 return (0);
948 }
949 }
950 /*
951 * If we are not suspended or have not yet reached suspended
952 * mode, then let the operation proceed.
953 */
954 if (mp == NULL)
955 return (0);
956 MNT_ILOCK(mp);
957 if (vp == NULL)
958 MNT_REF(mp);
959 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) == 0) {
960 MNT_REL(mp);
961 MNT_IUNLOCK(mp);
962 return (0);
963 }
964 if (flags & V_NOWAIT) {
965 MNT_REL(mp);
966 MNT_IUNLOCK(mp);
967 return (EWOULDBLOCK);
968 }
969 /*
970 * Wait for the suspension to finish.
971 */
972 error = msleep(&mp->mnt_flag, MNT_MTX(mp),
973 (PUSER - 1) | (flags & PCATCH) | PDROP, "suspfs", 0);
974 vfs_rel(mp);
975 return (error);
976 }
977
978 /*
979 * Secondary suspension. Used by operations such as vop_inactive
980 * routines that are needed by the higher level functions. These
981 * are allowed to proceed until all the higher level functions have
982 * completed (indicated by mnt_writeopcount dropping to zero). At that
983 * time, these operations are halted until the suspension is over.
984 */
985 int
986 vn_start_secondary_write(vp, mpp, flags)
987 struct vnode *vp;
988 struct mount **mpp;
989 int flags;
990 {
991 struct mount *mp;
992 int error;
993
994 retry:
995 if (vp != NULL) {
996 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
997 *mpp = NULL;
998 if (error != EOPNOTSUPP)
999 return (error);
1000 return (0);
1001 }
1002 }
1003 /*
1004 * If we are not suspended or have not yet reached suspended
1005 * mode, then let the operation proceed.
1006 */
1007 if ((mp = *mpp) == NULL)
1008 return (0);
1009 MNT_ILOCK(mp);
1010 if (vp == NULL)
1011 MNT_REF(mp);
1012 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) {
1013 mp->mnt_secondary_writes++;
1014 mp->mnt_secondary_accwrites++;
1015 MNT_REL(mp);
1016 MNT_IUNLOCK(mp);
1017 return (0);
1018 }
1019 if (flags & V_NOWAIT) {
1020 MNT_REL(mp);
1021 MNT_IUNLOCK(mp);
1022 return (EWOULDBLOCK);
1023 }
1024 /*
1025 * Wait for the suspension to finish.
1026 */
1027 error = msleep(&mp->mnt_flag, MNT_MTX(mp),
1028 (PUSER - 1) | (flags & PCATCH) | PDROP, "suspfs", 0);
1029 vfs_rel(mp);
1030 if (error == 0)
1031 goto retry;
1032 return (error);
1033 }
1034
1035 /*
1036 * Filesystem write operation has completed. If we are suspending and this
1037 * operation is the last one, notify the suspender that the suspension is
1038 * now in effect.
1039 */
1040 void
1041 vn_finished_write(mp)
1042 struct mount *mp;
1043 {
1044 if (mp == NULL)
1045 return;
1046 MNT_ILOCK(mp);
1047 mp->mnt_writeopcount--;
1048 if (mp->mnt_writeopcount < 0)
1049 panic("vn_finished_write: neg cnt");
1050 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
1051 mp->mnt_writeopcount <= 0)
1052 wakeup(&mp->mnt_writeopcount);
1053 MNT_IUNLOCK(mp);
1054 }
1055
1056
1057 /*
1058 * Filesystem secondary write operation has completed. If we are
1059 * suspending and this operation is the last one, notify the suspender
1060 * that the suspension is now in effect.
1061 */
1062 void
1063 vn_finished_secondary_write(mp)
1064 struct mount *mp;
1065 {
1066 if (mp == NULL)
1067 return;
1068 MNT_ILOCK(mp);
1069 mp->mnt_secondary_writes--;
1070 if (mp->mnt_secondary_writes < 0)
1071 panic("vn_finished_secondary_write: neg cnt");
1072 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
1073 mp->mnt_secondary_writes <= 0)
1074 wakeup(&mp->mnt_secondary_writes);
1075 MNT_IUNLOCK(mp);
1076 }
1077
1078
1079
1080 /*
1081 * Request a filesystem to suspend write operations.
1082 */
1083 int
1084 vfs_write_suspend(mp)
1085 struct mount *mp;
1086 {
1087 struct thread *td = curthread;
1088 int error;
1089
1090 MNT_ILOCK(mp);
1091 if (mp->mnt_kern_flag & MNTK_SUSPEND) {
1092 MNT_IUNLOCK(mp);
1093 return (0);
1094 }
1095 mp->mnt_kern_flag |= MNTK_SUSPEND;
1096 if (mp->mnt_writeopcount > 0)
1097 (void) msleep(&mp->mnt_writeopcount,
1098 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0);
1099 else
1100 MNT_IUNLOCK(mp);
1101 if ((error = VFS_SYNC(mp, MNT_SUSPEND, td)) != 0)
1102 vfs_write_resume(mp);
1103 return (error);
1104 }
1105
1106 /*
1107 * Request a filesystem to resume write operations.
1108 */
1109 void
1110 vfs_write_resume(mp)
1111 struct mount *mp;
1112 {
1113
1114 MNT_ILOCK(mp);
1115 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1116 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 |
1117 MNTK_SUSPENDED);
1118 wakeup(&mp->mnt_writeopcount);
1119 wakeup(&mp->mnt_flag);
1120 }
1121 MNT_IUNLOCK(mp);
1122 }
1123
1124 /*
1125 * Implement kqueues for files by translating it to vnode operation.
1126 */
1127 static int
1128 vn_kqfilter(struct file *fp, struct knote *kn)
1129 {
1130 int vfslocked;
1131 int error;
1132
1133 vfslocked = VFS_LOCK_GIANT(fp->f_vnode->v_mount);
1134 error = VOP_KQFILTER(fp->f_vnode, kn);
1135 VFS_UNLOCK_GIANT(vfslocked);
1136
1137 return error;
1138 }
1139
1140 /*
1141 * Simplified in-kernel wrapper calls for extended attribute access.
1142 * Both calls pass in a NULL credential, authorizing as "kernel" access.
1143 * Set IO_NODELOCKED in ioflg if the vnode is already locked.
1144 */
1145 int
1146 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace,
1147 const char *attrname, int *buflen, char *buf, struct thread *td)
1148 {
1149 struct uio auio;
1150 struct iovec iov;
1151 int error;
1152
1153 iov.iov_len = *buflen;
1154 iov.iov_base = buf;
1155
1156 auio.uio_iov = &iov;
1157 auio.uio_iovcnt = 1;
1158 auio.uio_rw = UIO_READ;
1159 auio.uio_segflg = UIO_SYSSPACE;
1160 auio.uio_td = td;
1161 auio.uio_offset = 0;
1162 auio.uio_resid = *buflen;
1163
1164 if ((ioflg & IO_NODELOCKED) == 0)
1165 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
1166
1167 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
1168
1169 /* authorize attribute retrieval as kernel */
1170 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL,
1171 td);
1172
1173 if ((ioflg & IO_NODELOCKED) == 0)
1174 VOP_UNLOCK(vp, 0, td);
1175
1176 if (error == 0) {
1177 *buflen = *buflen - auio.uio_resid;
1178 }
1179
1180 return (error);
1181 }
1182
1183 /*
1184 * XXX failure mode if partially written?
1185 */
1186 int
1187 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace,
1188 const char *attrname, int buflen, char *buf, struct thread *td)
1189 {
1190 struct uio auio;
1191 struct iovec iov;
1192 struct mount *mp;
1193 int error;
1194
1195 iov.iov_len = buflen;
1196 iov.iov_base = buf;
1197
1198 auio.uio_iov = &iov;
1199 auio.uio_iovcnt = 1;
1200 auio.uio_rw = UIO_WRITE;
1201 auio.uio_segflg = UIO_SYSSPACE;
1202 auio.uio_td = td;
1203 auio.uio_offset = 0;
1204 auio.uio_resid = buflen;
1205
1206 if ((ioflg & IO_NODELOCKED) == 0) {
1207 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
1208 return (error);
1209 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
1210 }
1211
1212 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
1213
1214 /* authorize attribute setting as kernel */
1215 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td);
1216
1217 if ((ioflg & IO_NODELOCKED) == 0) {
1218 vn_finished_write(mp);
1219 VOP_UNLOCK(vp, 0, td);
1220 }
1221
1222 return (error);
1223 }
1224
1225 int
1226 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace,
1227 const char *attrname, struct thread *td)
1228 {
1229 struct mount *mp;
1230 int error;
1231
1232 if ((ioflg & IO_NODELOCKED) == 0) {
1233 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
1234 return (error);
1235 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
1236 }
1237
1238 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
1239
1240 /* authorize attribute removal as kernel */
1241 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td);
1242 if (error == EOPNOTSUPP)
1243 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL,
1244 NULL, td);
1245
1246 if ((ioflg & IO_NODELOCKED) == 0) {
1247 vn_finished_write(mp);
1248 VOP_UNLOCK(vp, 0, td);
1249 }
1250
1251 return (error);
1252 }
Cache object: 12a62027555a213e0996098cddaf4df9
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