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 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
11 * Copyright (c) 2013 The FreeBSD Foundation
12 *
13 * Portions of this software were developed by Konstantin Belousov
14 * under sponsorship from the FreeBSD Foundation.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 * 1. Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution.
24 * 4. Neither the name of the University nor the names of its contributors
25 * may be used to endorse or promote products derived from this software
26 * without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * SUCH DAMAGE.
39 *
40 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94
41 */
42
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD: stable/9/sys/kern/vfs_vnops.c 259500 2013-12-17 09:22:25Z kib $");
45
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/fcntl.h>
49 #include <sys/file.h>
50 #include <sys/kdb.h>
51 #include <sys/stat.h>
52 #include <sys/priv.h>
53 #include <sys/proc.h>
54 #include <sys/limits.h>
55 #include <sys/lock.h>
56 #include <sys/mount.h>
57 #include <sys/mutex.h>
58 #include <sys/namei.h>
59 #include <sys/vnode.h>
60 #include <sys/bio.h>
61 #include <sys/buf.h>
62 #include <sys/filio.h>
63 #include <sys/resourcevar.h>
64 #include <sys/sx.h>
65 #include <sys/sysctl.h>
66 #include <sys/ttycom.h>
67 #include <sys/conf.h>
68 #include <sys/syslog.h>
69 #include <sys/unistd.h>
70
71 #include <security/audit/audit.h>
72 #include <security/mac/mac_framework.h>
73
74 #include <vm/vm.h>
75 #include <vm/vm_extern.h>
76 #include <vm/pmap.h>
77 #include <vm/vm_map.h>
78 #include <vm/vm_object.h>
79 #include <vm/vm_page.h>
80
81 static fo_rdwr_t vn_read;
82 static fo_rdwr_t vn_write;
83 static fo_rdwr_t vn_io_fault;
84 static fo_truncate_t vn_truncate;
85 static fo_ioctl_t vn_ioctl;
86 static fo_poll_t vn_poll;
87 static fo_kqfilter_t vn_kqfilter;
88 static fo_stat_t vn_statfile;
89 static fo_close_t vn_closefile;
90
91 struct fileops vnops = {
92 .fo_read = vn_io_fault,
93 .fo_write = vn_io_fault,
94 .fo_truncate = vn_truncate,
95 .fo_ioctl = vn_ioctl,
96 .fo_poll = vn_poll,
97 .fo_kqfilter = vn_kqfilter,
98 .fo_stat = vn_statfile,
99 .fo_close = vn_closefile,
100 .fo_chmod = vn_chmod,
101 .fo_chown = vn_chown,
102 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE
103 };
104
105 int
vn_open(ndp,flagp,cmode,fp)106 vn_open(ndp, flagp, cmode, fp)
107 struct nameidata *ndp;
108 int *flagp, cmode;
109 struct file *fp;
110 {
111 struct thread *td = ndp->ni_cnd.cn_thread;
112
113 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp));
114 }
115
116 /*
117 * Common code for vnode open operations.
118 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
119 *
120 * Note that this does NOT free nameidata for the successful case,
121 * due to the NDINIT being done elsewhere.
122 */
123 int
vn_open_cred(struct nameidata * ndp,int * flagp,int cmode,u_int vn_open_flags,struct ucred * cred,struct file * fp)124 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags,
125 struct ucred *cred, struct file *fp)
126 {
127 struct vnode *vp;
128 struct mount *mp;
129 struct thread *td = ndp->ni_cnd.cn_thread;
130 struct vattr vat;
131 struct vattr *vap = &vat;
132 int fmode, error;
133 accmode_t accmode;
134 int vfslocked, mpsafe;
135
136 mpsafe = ndp->ni_cnd.cn_flags & MPSAFE;
137 restart:
138 vfslocked = 0;
139 fmode = *flagp;
140 if (fmode & O_CREAT) {
141 ndp->ni_cnd.cn_nameiop = CREATE;
142 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF |
143 MPSAFE;
144 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
145 ndp->ni_cnd.cn_flags |= FOLLOW;
146 if (!(vn_open_flags & VN_OPEN_NOAUDIT))
147 ndp->ni_cnd.cn_flags |= AUDITVNODE1;
148 bwillwrite();
149 if ((error = namei(ndp)) != 0)
150 return (error);
151 vfslocked = NDHASGIANT(ndp);
152 if (!mpsafe)
153 ndp->ni_cnd.cn_flags &= ~MPSAFE;
154 if (ndp->ni_vp == NULL) {
155 VATTR_NULL(vap);
156 vap->va_type = VREG;
157 vap->va_mode = cmode;
158 if (fmode & O_EXCL)
159 vap->va_vaflags |= VA_EXCLUSIVE;
160 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) {
161 NDFREE(ndp, NDF_ONLY_PNBUF);
162 vput(ndp->ni_dvp);
163 VFS_UNLOCK_GIANT(vfslocked);
164 if ((error = vn_start_write(NULL, &mp,
165 V_XSLEEP | PCATCH)) != 0)
166 return (error);
167 goto restart;
168 }
169 #ifdef MAC
170 error = mac_vnode_check_create(cred, ndp->ni_dvp,
171 &ndp->ni_cnd, vap);
172 if (error == 0)
173 #endif
174 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
175 &ndp->ni_cnd, vap);
176 vput(ndp->ni_dvp);
177 vn_finished_write(mp);
178 if (error) {
179 VFS_UNLOCK_GIANT(vfslocked);
180 NDFREE(ndp, NDF_ONLY_PNBUF);
181 return (error);
182 }
183 fmode &= ~O_TRUNC;
184 vp = ndp->ni_vp;
185 } else {
186 if (ndp->ni_dvp == ndp->ni_vp)
187 vrele(ndp->ni_dvp);
188 else
189 vput(ndp->ni_dvp);
190 ndp->ni_dvp = NULL;
191 vp = ndp->ni_vp;
192 if (fmode & O_EXCL) {
193 error = EEXIST;
194 goto bad;
195 }
196 fmode &= ~O_CREAT;
197 }
198 } else {
199 ndp->ni_cnd.cn_nameiop = LOOKUP;
200 ndp->ni_cnd.cn_flags = ISOPEN |
201 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) |
202 LOCKLEAF | MPSAFE;
203 if (!(fmode & FWRITE))
204 ndp->ni_cnd.cn_flags |= LOCKSHARED;
205 if (!(vn_open_flags & VN_OPEN_NOAUDIT))
206 ndp->ni_cnd.cn_flags |= AUDITVNODE1;
207 if ((error = namei(ndp)) != 0)
208 return (error);
209 if (!mpsafe)
210 ndp->ni_cnd.cn_flags &= ~MPSAFE;
211 vfslocked = NDHASGIANT(ndp);
212 vp = ndp->ni_vp;
213 }
214 if (vp->v_type == VLNK) {
215 error = EMLINK;
216 goto bad;
217 }
218 if (vp->v_type == VSOCK) {
219 error = EOPNOTSUPP;
220 goto bad;
221 }
222 if (vp->v_type != VDIR && fmode & O_DIRECTORY) {
223 error = ENOTDIR;
224 goto bad;
225 }
226 accmode = 0;
227 if (fmode & (FWRITE | O_TRUNC)) {
228 if (vp->v_type == VDIR) {
229 error = EISDIR;
230 goto bad;
231 }
232 accmode |= VWRITE;
233 }
234 if (fmode & FREAD)
235 accmode |= VREAD;
236 if (fmode & FEXEC)
237 accmode |= VEXEC;
238 if ((fmode & O_APPEND) && (fmode & FWRITE))
239 accmode |= VAPPEND;
240 #ifdef MAC
241 error = mac_vnode_check_open(cred, vp, accmode);
242 if (error)
243 goto bad;
244 #endif
245 if ((fmode & O_CREAT) == 0) {
246 if (accmode & VWRITE) {
247 error = vn_writechk(vp);
248 if (error)
249 goto bad;
250 }
251 if (accmode) {
252 error = VOP_ACCESS(vp, accmode, cred, td);
253 if (error)
254 goto bad;
255 }
256 }
257 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
258 vn_lock(vp, LK_UPGRADE | LK_RETRY);
259 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0)
260 goto bad;
261
262 if (fmode & FWRITE)
263 VOP_ADD_WRITECOUNT(vp, 1);
264 *flagp = fmode;
265 ASSERT_VOP_LOCKED(vp, "vn_open_cred");
266 if (!mpsafe)
267 VFS_UNLOCK_GIANT(vfslocked);
268 return (0);
269 bad:
270 NDFREE(ndp, NDF_ONLY_PNBUF);
271 vput(vp);
272 VFS_UNLOCK_GIANT(vfslocked);
273 *flagp = fmode;
274 ndp->ni_vp = NULL;
275 return (error);
276 }
277
278 /*
279 * Check for write permissions on the specified vnode.
280 * Prototype text segments cannot be written.
281 */
282 int
vn_writechk(vp)283 vn_writechk(vp)
284 register struct vnode *vp;
285 {
286
287 ASSERT_VOP_LOCKED(vp, "vn_writechk");
288 /*
289 * If there's shared text associated with
290 * the vnode, try to free it up once. If
291 * we fail, we can't allow writing.
292 */
293 if (VOP_IS_TEXT(vp))
294 return (ETXTBSY);
295
296 return (0);
297 }
298
299 /*
300 * Vnode close call
301 */
302 int
vn_close(vp,flags,file_cred,td)303 vn_close(vp, flags, file_cred, td)
304 register struct vnode *vp;
305 int flags;
306 struct ucred *file_cred;
307 struct thread *td;
308 {
309 struct mount *mp;
310 int error, lock_flags;
311
312 if (vp->v_type != VFIFO && !(flags & FWRITE) && vp->v_mount != NULL &&
313 vp->v_mount->mnt_kern_flag & MNTK_EXTENDED_SHARED)
314 lock_flags = LK_SHARED;
315 else
316 lock_flags = LK_EXCLUSIVE;
317
318 VFS_ASSERT_GIANT(vp->v_mount);
319
320 vn_start_write(vp, &mp, V_WAIT);
321 vn_lock(vp, lock_flags | LK_RETRY);
322 if (flags & FWRITE) {
323 VNASSERT(vp->v_writecount > 0, vp,
324 ("vn_close: negative writecount"));
325 VOP_ADD_WRITECOUNT(vp, -1);
326 }
327 error = VOP_CLOSE(vp, flags, file_cred, td);
328 vput(vp);
329 vn_finished_write(mp);
330 return (error);
331 }
332
333 /*
334 * Heuristic to detect sequential operation.
335 */
336 static int
sequential_heuristic(struct uio * uio,struct file * fp)337 sequential_heuristic(struct uio *uio, struct file *fp)
338 {
339
340 if (atomic_load_acq_int(&(fp->f_flag)) & FRDAHEAD)
341 return (fp->f_seqcount << IO_SEQSHIFT);
342
343 /*
344 * Offset 0 is handled specially. open() sets f_seqcount to 1 so
345 * that the first I/O is normally considered to be slightly
346 * sequential. Seeking to offset 0 doesn't change sequentiality
347 * unless previous seeks have reduced f_seqcount to 0, in which
348 * case offset 0 is not special.
349 */
350 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) ||
351 uio->uio_offset == fp->f_nextoff) {
352 /*
353 * f_seqcount is in units of fixed-size blocks so that it
354 * depends mainly on the amount of sequential I/O and not
355 * much on the number of sequential I/O's. The fixed size
356 * of 16384 is hard-coded here since it is (not quite) just
357 * a magic size that works well here. This size is more
358 * closely related to the best I/O size for real disks than
359 * to any block size used by software.
360 */
361 fp->f_seqcount += howmany(uio->uio_resid, 16384);
362 if (fp->f_seqcount > IO_SEQMAX)
363 fp->f_seqcount = IO_SEQMAX;
364 return (fp->f_seqcount << IO_SEQSHIFT);
365 }
366
367 /* Not sequential. Quickly draw-down sequentiality. */
368 if (fp->f_seqcount > 1)
369 fp->f_seqcount = 1;
370 else
371 fp->f_seqcount = 0;
372 return (0);
373 }
374
375 /*
376 * Package up an I/O request on a vnode into a uio and do it.
377 */
378 int
vn_rdwr(enum uio_rw rw,struct vnode * vp,void * base,int len,off_t offset,enum uio_seg segflg,int ioflg,struct ucred * active_cred,struct ucred * file_cred,ssize_t * aresid,struct thread * td)379 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset,
380 enum uio_seg segflg, int ioflg, struct ucred *active_cred,
381 struct ucred *file_cred, ssize_t *aresid, struct thread *td)
382 {
383 struct uio auio;
384 struct iovec aiov;
385 struct mount *mp;
386 struct ucred *cred;
387 void *rl_cookie;
388 int error, lock_flags;
389
390 VFS_ASSERT_GIANT(vp->v_mount);
391
392 auio.uio_iov = &aiov;
393 auio.uio_iovcnt = 1;
394 aiov.iov_base = base;
395 aiov.iov_len = len;
396 auio.uio_resid = len;
397 auio.uio_offset = offset;
398 auio.uio_segflg = segflg;
399 auio.uio_rw = rw;
400 auio.uio_td = td;
401 error = 0;
402
403 if ((ioflg & IO_NODELOCKED) == 0) {
404 if (rw == UIO_READ) {
405 rl_cookie = vn_rangelock_rlock(vp, offset,
406 offset + len);
407 } else {
408 rl_cookie = vn_rangelock_wlock(vp, offset,
409 offset + len);
410 }
411 mp = NULL;
412 if (rw == UIO_WRITE) {
413 if (vp->v_type != VCHR &&
414 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH))
415 != 0)
416 goto out;
417 if (MNT_SHARED_WRITES(mp) ||
418 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount)))
419 lock_flags = LK_SHARED;
420 else
421 lock_flags = LK_EXCLUSIVE;
422 } else
423 lock_flags = LK_SHARED;
424 vn_lock(vp, lock_flags | LK_RETRY);
425 } else
426 rl_cookie = NULL;
427
428 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
429 #ifdef MAC
430 if ((ioflg & IO_NOMACCHECK) == 0) {
431 if (rw == UIO_READ)
432 error = mac_vnode_check_read(active_cred, file_cred,
433 vp);
434 else
435 error = mac_vnode_check_write(active_cred, file_cred,
436 vp);
437 }
438 #endif
439 if (error == 0) {
440 if (file_cred != NULL)
441 cred = file_cred;
442 else
443 cred = active_cred;
444 if (rw == UIO_READ)
445 error = VOP_READ(vp, &auio, ioflg, cred);
446 else
447 error = VOP_WRITE(vp, &auio, ioflg, cred);
448 }
449 if (aresid)
450 *aresid = auio.uio_resid;
451 else
452 if (auio.uio_resid && error == 0)
453 error = EIO;
454 if ((ioflg & IO_NODELOCKED) == 0) {
455 VOP_UNLOCK(vp, 0);
456 if (mp != NULL)
457 vn_finished_write(mp);
458 }
459 out:
460 if (rl_cookie != NULL)
461 vn_rangelock_unlock(vp, rl_cookie);
462 return (error);
463 }
464
465 /*
466 * Package up an I/O request on a vnode into a uio and do it. The I/O
467 * request is split up into smaller chunks and we try to avoid saturating
468 * the buffer cache while potentially holding a vnode locked, so we
469 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield()
470 * to give other processes a chance to lock the vnode (either other processes
471 * core'ing the same binary, or unrelated processes scanning the directory).
472 */
473 int
vn_rdwr_inchunks(rw,vp,base,len,offset,segflg,ioflg,active_cred,file_cred,aresid,td)474 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred,
475 file_cred, aresid, td)
476 enum uio_rw rw;
477 struct vnode *vp;
478 void *base;
479 size_t len;
480 off_t offset;
481 enum uio_seg segflg;
482 int ioflg;
483 struct ucred *active_cred;
484 struct ucred *file_cred;
485 size_t *aresid;
486 struct thread *td;
487 {
488 int error = 0;
489 ssize_t iaresid;
490
491 VFS_ASSERT_GIANT(vp->v_mount);
492
493 do {
494 int chunk;
495
496 /*
497 * Force `offset' to a multiple of MAXBSIZE except possibly
498 * for the first chunk, so that filesystems only need to
499 * write full blocks except possibly for the first and last
500 * chunks.
501 */
502 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE;
503
504 if (chunk > len)
505 chunk = len;
506 if (rw != UIO_READ && vp->v_type == VREG)
507 bwillwrite();
508 iaresid = 0;
509 error = vn_rdwr(rw, vp, base, chunk, offset, segflg,
510 ioflg, active_cred, file_cred, &iaresid, td);
511 len -= chunk; /* aresid calc already includes length */
512 if (error)
513 break;
514 offset += chunk;
515 base = (char *)base + chunk;
516 kern_yield(PRI_USER);
517 } while (len);
518 if (aresid)
519 *aresid = len + iaresid;
520 return (error);
521 }
522
523 off_t
foffset_lock(struct file * fp,int flags)524 foffset_lock(struct file *fp, int flags)
525 {
526 struct mtx *mtxp;
527 off_t res;
528
529 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
530
531 #if OFF_MAX <= LONG_MAX
532 /*
533 * Caller only wants the current f_offset value. Assume that
534 * the long and shorter integer types reads are atomic.
535 */
536 if ((flags & FOF_NOLOCK) != 0)
537 return (fp->f_offset);
538 #endif
539
540 /*
541 * According to McKusick the vn lock was protecting f_offset here.
542 * It is now protected by the FOFFSET_LOCKED flag.
543 */
544 mtxp = mtx_pool_find(mtxpool_sleep, fp);
545 mtx_lock(mtxp);
546 if ((flags & FOF_NOLOCK) == 0) {
547 while (fp->f_vnread_flags & FOFFSET_LOCKED) {
548 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING;
549 msleep(&fp->f_vnread_flags, mtxp, PUSER -1,
550 "vofflock", 0);
551 }
552 fp->f_vnread_flags |= FOFFSET_LOCKED;
553 }
554 res = fp->f_offset;
555 mtx_unlock(mtxp);
556 return (res);
557 }
558
559 void
foffset_unlock(struct file * fp,off_t val,int flags)560 foffset_unlock(struct file *fp, off_t val, int flags)
561 {
562 struct mtx *mtxp;
563
564 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
565
566 #if OFF_MAX <= LONG_MAX
567 if ((flags & FOF_NOLOCK) != 0) {
568 if ((flags & FOF_NOUPDATE) == 0)
569 fp->f_offset = val;
570 if ((flags & FOF_NEXTOFF) != 0)
571 fp->f_nextoff = val;
572 return;
573 }
574 #endif
575
576 mtxp = mtx_pool_find(mtxpool_sleep, fp);
577 mtx_lock(mtxp);
578 if ((flags & FOF_NOUPDATE) == 0)
579 fp->f_offset = val;
580 if ((flags & FOF_NEXTOFF) != 0)
581 fp->f_nextoff = val;
582 if ((flags & FOF_NOLOCK) == 0) {
583 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0,
584 ("Lost FOFFSET_LOCKED"));
585 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING)
586 wakeup(&fp->f_vnread_flags);
587 fp->f_vnread_flags = 0;
588 }
589 mtx_unlock(mtxp);
590 }
591
592 void
foffset_lock_uio(struct file * fp,struct uio * uio,int flags)593 foffset_lock_uio(struct file *fp, struct uio *uio, int flags)
594 {
595
596 if ((flags & FOF_OFFSET) == 0)
597 uio->uio_offset = foffset_lock(fp, flags);
598 }
599
600 void
foffset_unlock_uio(struct file * fp,struct uio * uio,int flags)601 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags)
602 {
603
604 if ((flags & FOF_OFFSET) == 0)
605 foffset_unlock(fp, uio->uio_offset, flags);
606 }
607
608 static int
get_advice(struct file * fp,struct uio * uio)609 get_advice(struct file *fp, struct uio *uio)
610 {
611 struct mtx *mtxp;
612 int ret;
613
614 ret = POSIX_FADV_NORMAL;
615 if (fp->f_advice == NULL)
616 return (ret);
617
618 mtxp = mtx_pool_find(mtxpool_sleep, fp);
619 mtx_lock(mtxp);
620 if (uio->uio_offset >= fp->f_advice->fa_start &&
621 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end)
622 ret = fp->f_advice->fa_advice;
623 mtx_unlock(mtxp);
624 return (ret);
625 }
626
627 /*
628 * File table vnode read routine.
629 */
630 static int
vn_read(fp,uio,active_cred,flags,td)631 vn_read(fp, uio, active_cred, flags, td)
632 struct file *fp;
633 struct uio *uio;
634 struct ucred *active_cred;
635 int flags;
636 struct thread *td;
637 {
638 struct vnode *vp;
639 struct mtx *mtxp;
640 int error, ioflag;
641 int advice, vfslocked;
642 off_t offset, start, end;
643
644 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
645 uio->uio_td, td));
646 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
647 vp = fp->f_vnode;
648 ioflag = 0;
649 if (fp->f_flag & FNONBLOCK)
650 ioflag |= IO_NDELAY;
651 if (fp->f_flag & O_DIRECT)
652 ioflag |= IO_DIRECT;
653 advice = get_advice(fp, uio);
654 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
655 vn_lock(vp, LK_SHARED | LK_RETRY);
656
657 switch (advice) {
658 case POSIX_FADV_NORMAL:
659 case POSIX_FADV_SEQUENTIAL:
660 case POSIX_FADV_NOREUSE:
661 ioflag |= sequential_heuristic(uio, fp);
662 break;
663 case POSIX_FADV_RANDOM:
664 /* Disable read-ahead for random I/O. */
665 break;
666 }
667 offset = uio->uio_offset;
668
669 #ifdef MAC
670 error = mac_vnode_check_read(active_cred, fp->f_cred, vp);
671 if (error == 0)
672 #endif
673 error = VOP_READ(vp, uio, ioflag, fp->f_cred);
674 fp->f_nextoff = uio->uio_offset;
675 VOP_UNLOCK(vp, 0);
676 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
677 offset != uio->uio_offset) {
678 /*
679 * Use POSIX_FADV_DONTNEED to flush clean pages and
680 * buffers for the backing file after a
681 * POSIX_FADV_NOREUSE read(2). To optimize the common
682 * case of using POSIX_FADV_NOREUSE with sequential
683 * access, track the previous implicit DONTNEED
684 * request and grow this request to include the
685 * current read(2) in addition to the previous
686 * DONTNEED. With purely sequential access this will
687 * cause the DONTNEED requests to continously grow to
688 * cover all of the previously read regions of the
689 * file. This allows filesystem blocks that are
690 * accessed by multiple calls to read(2) to be flushed
691 * once the last read(2) finishes.
692 */
693 start = offset;
694 end = uio->uio_offset - 1;
695 mtxp = mtx_pool_find(mtxpool_sleep, fp);
696 mtx_lock(mtxp);
697 if (fp->f_advice != NULL &&
698 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) {
699 if (start != 0 && fp->f_advice->fa_prevend + 1 == start)
700 start = fp->f_advice->fa_prevstart;
701 else if (fp->f_advice->fa_prevstart != 0 &&
702 fp->f_advice->fa_prevstart == end + 1)
703 end = fp->f_advice->fa_prevend;
704 fp->f_advice->fa_prevstart = start;
705 fp->f_advice->fa_prevend = end;
706 }
707 mtx_unlock(mtxp);
708 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED);
709 }
710 VFS_UNLOCK_GIANT(vfslocked);
711 return (error);
712 }
713
714 /*
715 * File table vnode write routine.
716 */
717 static int
vn_write(fp,uio,active_cred,flags,td)718 vn_write(fp, uio, active_cred, flags, td)
719 struct file *fp;
720 struct uio *uio;
721 struct ucred *active_cred;
722 int flags;
723 struct thread *td;
724 {
725 struct vnode *vp;
726 struct mount *mp;
727 struct mtx *mtxp;
728 int error, ioflag, lock_flags;
729 int advice, vfslocked;
730 off_t offset, start, end;
731
732 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
733 uio->uio_td, td));
734 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
735 vp = fp->f_vnode;
736 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
737 if (vp->v_type == VREG)
738 bwillwrite();
739 ioflag = IO_UNIT;
740 if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
741 ioflag |= IO_APPEND;
742 if (fp->f_flag & FNONBLOCK)
743 ioflag |= IO_NDELAY;
744 if (fp->f_flag & O_DIRECT)
745 ioflag |= IO_DIRECT;
746 if ((fp->f_flag & O_FSYNC) ||
747 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
748 ioflag |= IO_SYNC;
749 mp = NULL;
750 if (vp->v_type != VCHR &&
751 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
752 goto unlock;
753
754 advice = get_advice(fp, uio);
755
756 if ((MNT_SHARED_WRITES(mp) ||
757 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) &&
758 (flags & FOF_OFFSET) != 0) {
759 lock_flags = LK_SHARED;
760 } else {
761 lock_flags = LK_EXCLUSIVE;
762 }
763
764 vn_lock(vp, lock_flags | LK_RETRY);
765 switch (advice) {
766 case POSIX_FADV_NORMAL:
767 case POSIX_FADV_SEQUENTIAL:
768 case POSIX_FADV_NOREUSE:
769 ioflag |= sequential_heuristic(uio, fp);
770 break;
771 case POSIX_FADV_RANDOM:
772 /* XXX: Is this correct? */
773 break;
774 }
775 offset = uio->uio_offset;
776
777 #ifdef MAC
778 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
779 if (error == 0)
780 #endif
781 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred);
782 fp->f_nextoff = uio->uio_offset;
783 VOP_UNLOCK(vp, 0);
784 if (vp->v_type != VCHR)
785 vn_finished_write(mp);
786 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
787 offset != uio->uio_offset) {
788 /*
789 * Use POSIX_FADV_DONTNEED to flush clean pages and
790 * buffers for the backing file after a
791 * POSIX_FADV_NOREUSE write(2). To optimize the
792 * common case of using POSIX_FADV_NOREUSE with
793 * sequential access, track the previous implicit
794 * DONTNEED request and grow this request to include
795 * the current write(2) in addition to the previous
796 * DONTNEED. With purely sequential access this will
797 * cause the DONTNEED requests to continously grow to
798 * cover all of the previously written regions of the
799 * file.
800 *
801 * Note that the blocks just written are almost
802 * certainly still dirty, so this only works when
803 * VOP_ADVISE() calls from subsequent writes push out
804 * the data written by this write(2) once the backing
805 * buffers are clean. However, as compared to forcing
806 * IO_DIRECT, this gives much saner behavior. Write
807 * clustering is still allowed, and clean pages are
808 * merely moved to the cache page queue rather than
809 * outright thrown away. This means a subsequent
810 * read(2) can still avoid hitting the disk if the
811 * pages have not been reclaimed.
812 *
813 * This does make POSIX_FADV_NOREUSE largely useless
814 * with non-sequential access. However, sequential
815 * access is the more common use case and the flag is
816 * merely advisory.
817 */
818 start = offset;
819 end = uio->uio_offset - 1;
820 mtxp = mtx_pool_find(mtxpool_sleep, fp);
821 mtx_lock(mtxp);
822 if (fp->f_advice != NULL &&
823 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) {
824 if (start != 0 && fp->f_advice->fa_prevend + 1 == start)
825 start = fp->f_advice->fa_prevstart;
826 else if (fp->f_advice->fa_prevstart != 0 &&
827 fp->f_advice->fa_prevstart == end + 1)
828 end = fp->f_advice->fa_prevend;
829 fp->f_advice->fa_prevstart = start;
830 fp->f_advice->fa_prevend = end;
831 }
832 mtx_unlock(mtxp);
833 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED);
834 }
835
836 unlock:
837 VFS_UNLOCK_GIANT(vfslocked);
838 return (error);
839 }
840
841 static const int io_hold_cnt = 16;
842 static int vn_io_fault_enable = 0;
843 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW,
844 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance");
845 static u_long vn_io_faults_cnt;
846 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD,
847 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers");
848
849 /*
850 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to
851 * prevent the following deadlock:
852 *
853 * Assume that the thread A reads from the vnode vp1 into userspace
854 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is
855 * currently not resident, then system ends up with the call chain
856 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] ->
857 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2)
858 * which establishes lock order vp1->vn_lock, then vp2->vn_lock.
859 * If, at the same time, thread B reads from vnode vp2 into buffer buf2
860 * backed by the pages of vnode vp1, and some page in buf2 is not
861 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock.
862 *
863 * To prevent the lock order reversal and deadlock, vn_io_fault() does
864 * not allow page faults to happen during VOP_READ() or VOP_WRITE().
865 * Instead, it first tries to do the whole range i/o with pagefaults
866 * disabled. If all pages in the i/o buffer are resident and mapped,
867 * VOP will succeed (ignoring the genuine filesystem errors).
868 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do
869 * i/o in chunks, with all pages in the chunk prefaulted and held
870 * using vm_fault_quick_hold_pages().
871 *
872 * Filesystems using this deadlock avoidance scheme should use the
873 * array of the held pages from uio, saved in the curthread->td_ma,
874 * instead of doing uiomove(). A helper function
875 * vn_io_fault_uiomove() converts uiomove request into
876 * uiomove_fromphys() over td_ma array.
877 *
878 * Since vnode locks do not cover the whole i/o anymore, rangelocks
879 * make the current i/o request atomic with respect to other i/os and
880 * truncations.
881 */
882 static int
vn_io_fault(struct file * fp,struct uio * uio,struct ucred * active_cred,int flags,struct thread * td)883 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred,
884 int flags, struct thread *td)
885 {
886 vm_page_t ma[io_hold_cnt + 2];
887 struct uio *uio_clone, short_uio;
888 struct iovec short_iovec[1];
889 fo_rdwr_t *doio;
890 struct vnode *vp;
891 void *rl_cookie;
892 struct mount *mp;
893 vm_page_t *prev_td_ma;
894 int error, cnt, save, saveheld, prev_td_ma_cnt;
895 vm_offset_t addr, end;
896 vm_prot_t prot;
897 size_t len, resid;
898 ssize_t adv;
899
900 if (uio->uio_rw == UIO_READ)
901 doio = vn_read;
902 else
903 doio = vn_write;
904 vp = fp->f_vnode;
905 foffset_lock_uio(fp, uio, flags);
906
907 if (uio->uio_segflg != UIO_USERSPACE || vp->v_type != VREG ||
908 ((mp = vp->v_mount) != NULL &&
909 (mp->mnt_kern_flag & MNTK_NO_IOPF) == 0) ||
910 !vn_io_fault_enable) {
911 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td);
912 goto out_last;
913 }
914
915 /*
916 * The UFS follows IO_UNIT directive and replays back both
917 * uio_offset and uio_resid if an error is encountered during the
918 * operation. But, since the iovec may be already advanced,
919 * uio is still in an inconsistent state.
920 *
921 * Cache a copy of the original uio, which is advanced to the redo
922 * point using UIO_NOCOPY below.
923 */
924 uio_clone = cloneuio(uio);
925 resid = uio->uio_resid;
926
927 short_uio.uio_segflg = UIO_USERSPACE;
928 short_uio.uio_rw = uio->uio_rw;
929 short_uio.uio_td = uio->uio_td;
930
931 if (uio->uio_rw == UIO_READ) {
932 prot = VM_PROT_WRITE;
933 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset,
934 uio->uio_offset + uio->uio_resid);
935 } else {
936 prot = VM_PROT_READ;
937 if ((fp->f_flag & O_APPEND) != 0 || (flags & FOF_OFFSET) == 0)
938 /* For appenders, punt and lock the whole range. */
939 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
940 else
941 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset,
942 uio->uio_offset + uio->uio_resid);
943 }
944
945 save = vm_fault_disable_pagefaults();
946 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td);
947 if (error != EFAULT)
948 goto out;
949
950 atomic_add_long(&vn_io_faults_cnt, 1);
951 uio_clone->uio_segflg = UIO_NOCOPY;
952 uiomove(NULL, resid - uio->uio_resid, uio_clone);
953 uio_clone->uio_segflg = uio->uio_segflg;
954
955 saveheld = curthread_pflags_set(TDP_UIOHELD);
956 prev_td_ma = td->td_ma;
957 prev_td_ma_cnt = td->td_ma_cnt;
958
959 while (uio_clone->uio_resid != 0) {
960 len = uio_clone->uio_iov->iov_len;
961 if (len == 0) {
962 KASSERT(uio_clone->uio_iovcnt >= 1,
963 ("iovcnt underflow"));
964 uio_clone->uio_iov++;
965 uio_clone->uio_iovcnt--;
966 continue;
967 }
968 if (len > io_hold_cnt * PAGE_SIZE)
969 len = io_hold_cnt * PAGE_SIZE;
970 addr = (uintptr_t)uio_clone->uio_iov->iov_base;
971 end = round_page(addr + len);
972 if (end < addr) {
973 error = EFAULT;
974 break;
975 }
976 cnt = atop(end - trunc_page(addr));
977 /*
978 * A perfectly misaligned address and length could cause
979 * both the start and the end of the chunk to use partial
980 * page. +2 accounts for such a situation.
981 */
982 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map,
983 addr, len, prot, ma, io_hold_cnt + 2);
984 if (cnt == -1) {
985 error = EFAULT;
986 break;
987 }
988 short_uio.uio_iov = &short_iovec[0];
989 short_iovec[0].iov_base = (void *)addr;
990 short_uio.uio_iovcnt = 1;
991 short_uio.uio_resid = short_iovec[0].iov_len = len;
992 short_uio.uio_offset = uio_clone->uio_offset;
993 td->td_ma = ma;
994 td->td_ma_cnt = cnt;
995
996 error = doio(fp, &short_uio, active_cred, flags | FOF_OFFSET,
997 td);
998 vm_page_unhold_pages(ma, cnt);
999 adv = len - short_uio.uio_resid;
1000
1001 uio_clone->uio_iov->iov_base =
1002 (char *)uio_clone->uio_iov->iov_base + adv;
1003 uio_clone->uio_iov->iov_len -= adv;
1004 uio_clone->uio_resid -= adv;
1005 uio_clone->uio_offset += adv;
1006
1007 uio->uio_resid -= adv;
1008 uio->uio_offset += adv;
1009
1010 if (error != 0 || adv == 0)
1011 break;
1012 }
1013 td->td_ma = prev_td_ma;
1014 td->td_ma_cnt = prev_td_ma_cnt;
1015 curthread_pflags_restore(saveheld);
1016 out:
1017 vm_fault_enable_pagefaults(save);
1018 vn_rangelock_unlock(vp, rl_cookie);
1019 free(uio_clone, M_IOV);
1020 out_last:
1021 foffset_unlock_uio(fp, uio, flags);
1022 return (error);
1023 }
1024
1025 /*
1026 * Helper function to perform the requested uiomove operation using
1027 * the held pages for io->uio_iov[0].iov_base buffer instead of
1028 * copyin/copyout. Access to the pages with uiomove_fromphys()
1029 * instead of iov_base prevents page faults that could occur due to
1030 * pmap_collect() invalidating the mapping created by
1031 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or
1032 * object cleanup revoking the write access from page mappings.
1033 *
1034 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove()
1035 * instead of plain uiomove().
1036 */
1037 int
vn_io_fault_uiomove(char * data,int xfersize,struct uio * uio)1038 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio)
1039 {
1040 struct uio transp_uio;
1041 struct iovec transp_iov[1];
1042 struct thread *td;
1043 size_t adv;
1044 int error, pgadv;
1045
1046 td = curthread;
1047 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1048 uio->uio_segflg != UIO_USERSPACE)
1049 return (uiomove(data, xfersize, uio));
1050
1051 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1052 transp_iov[0].iov_base = data;
1053 transp_uio.uio_iov = &transp_iov[0];
1054 transp_uio.uio_iovcnt = 1;
1055 if (xfersize > uio->uio_resid)
1056 xfersize = uio->uio_resid;
1057 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize;
1058 transp_uio.uio_offset = 0;
1059 transp_uio.uio_segflg = UIO_SYSSPACE;
1060 /*
1061 * Since transp_iov points to data, and td_ma page array
1062 * corresponds to original uio->uio_iov, we need to invert the
1063 * direction of the i/o operation as passed to
1064 * uiomove_fromphys().
1065 */
1066 switch (uio->uio_rw) {
1067 case UIO_WRITE:
1068 transp_uio.uio_rw = UIO_READ;
1069 break;
1070 case UIO_READ:
1071 transp_uio.uio_rw = UIO_WRITE;
1072 break;
1073 }
1074 transp_uio.uio_td = uio->uio_td;
1075 error = uiomove_fromphys(td->td_ma,
1076 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK,
1077 xfersize, &transp_uio);
1078 adv = xfersize - transp_uio.uio_resid;
1079 pgadv =
1080 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) -
1081 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT);
1082 td->td_ma += pgadv;
1083 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1084 pgadv));
1085 td->td_ma_cnt -= pgadv;
1086 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv;
1087 uio->uio_iov->iov_len -= adv;
1088 uio->uio_resid -= adv;
1089 uio->uio_offset += adv;
1090 return (error);
1091 }
1092
1093 int
vn_io_fault_pgmove(vm_page_t ma[],vm_offset_t offset,int xfersize,struct uio * uio)1094 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize,
1095 struct uio *uio)
1096 {
1097 struct thread *td;
1098 vm_offset_t iov_base;
1099 int cnt, pgadv;
1100
1101 td = curthread;
1102 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1103 uio->uio_segflg != UIO_USERSPACE)
1104 return (uiomove_fromphys(ma, offset, xfersize, uio));
1105
1106 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1107 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize;
1108 iov_base = (vm_offset_t)uio->uio_iov->iov_base;
1109 switch (uio->uio_rw) {
1110 case UIO_WRITE:
1111 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma,
1112 offset, cnt);
1113 break;
1114 case UIO_READ:
1115 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK,
1116 cnt);
1117 break;
1118 }
1119 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT);
1120 td->td_ma += pgadv;
1121 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1122 pgadv));
1123 td->td_ma_cnt -= pgadv;
1124 uio->uio_iov->iov_base = (char *)(iov_base + cnt);
1125 uio->uio_iov->iov_len -= cnt;
1126 uio->uio_resid -= cnt;
1127 uio->uio_offset += cnt;
1128 return (0);
1129 }
1130
1131
1132 /*
1133 * File table truncate routine.
1134 */
1135 static int
vn_truncate(struct file * fp,off_t length,struct ucred * active_cred,struct thread * td)1136 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred,
1137 struct thread *td)
1138 {
1139 struct vattr vattr;
1140 struct mount *mp;
1141 struct vnode *vp;
1142 void *rl_cookie;
1143 int vfslocked;
1144 int error;
1145
1146 vp = fp->f_vnode;
1147
1148 /*
1149 * Lock the whole range for truncation. Otherwise split i/o
1150 * might happen partly before and partly after the truncation.
1151 */
1152 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1153 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
1154 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
1155 if (error)
1156 goto out1;
1157 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1158 if (vp->v_type == VDIR) {
1159 error = EISDIR;
1160 goto out;
1161 }
1162 #ifdef MAC
1163 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
1164 if (error)
1165 goto out;
1166 #endif
1167 error = vn_writechk(vp);
1168 if (error == 0) {
1169 VATTR_NULL(&vattr);
1170 vattr.va_size = length;
1171 error = VOP_SETATTR(vp, &vattr, fp->f_cred);
1172 }
1173 out:
1174 VOP_UNLOCK(vp, 0);
1175 vn_finished_write(mp);
1176 out1:
1177 VFS_UNLOCK_GIANT(vfslocked);
1178 vn_rangelock_unlock(vp, rl_cookie);
1179 return (error);
1180 }
1181
1182 /*
1183 * File table vnode stat routine.
1184 */
1185 static int
vn_statfile(fp,sb,active_cred,td)1186 vn_statfile(fp, sb, active_cred, td)
1187 struct file *fp;
1188 struct stat *sb;
1189 struct ucred *active_cred;
1190 struct thread *td;
1191 {
1192 struct vnode *vp = fp->f_vnode;
1193 int vfslocked;
1194 int error;
1195
1196 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
1197 vn_lock(vp, LK_SHARED | LK_RETRY);
1198 error = vn_stat(vp, sb, active_cred, fp->f_cred, td);
1199 VOP_UNLOCK(vp, 0);
1200 VFS_UNLOCK_GIANT(vfslocked);
1201
1202 return (error);
1203 }
1204
1205 /*
1206 * Stat a vnode; implementation for the stat syscall
1207 */
1208 int
vn_stat(vp,sb,active_cred,file_cred,td)1209 vn_stat(vp, sb, active_cred, file_cred, td)
1210 struct vnode *vp;
1211 register struct stat *sb;
1212 struct ucred *active_cred;
1213 struct ucred *file_cred;
1214 struct thread *td;
1215 {
1216 struct vattr vattr;
1217 register struct vattr *vap;
1218 int error;
1219 u_short mode;
1220
1221 #ifdef MAC
1222 error = mac_vnode_check_stat(active_cred, file_cred, vp);
1223 if (error)
1224 return (error);
1225 #endif
1226
1227 vap = &vattr;
1228
1229 /*
1230 * Initialize defaults for new and unusual fields, so that file
1231 * systems which don't support these fields don't need to know
1232 * about them.
1233 */
1234 vap->va_birthtime.tv_sec = -1;
1235 vap->va_birthtime.tv_nsec = 0;
1236 vap->va_fsid = VNOVAL;
1237 vap->va_rdev = NODEV;
1238
1239 error = VOP_GETATTR(vp, vap, active_cred);
1240 if (error)
1241 return (error);
1242
1243 /*
1244 * Zero the spare stat fields
1245 */
1246 bzero(sb, sizeof *sb);
1247
1248 /*
1249 * Copy from vattr table
1250 */
1251 if (vap->va_fsid != VNOVAL)
1252 sb->st_dev = vap->va_fsid;
1253 else
1254 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0];
1255 sb->st_ino = vap->va_fileid;
1256 mode = vap->va_mode;
1257 switch (vap->va_type) {
1258 case VREG:
1259 mode |= S_IFREG;
1260 break;
1261 case VDIR:
1262 mode |= S_IFDIR;
1263 break;
1264 case VBLK:
1265 mode |= S_IFBLK;
1266 break;
1267 case VCHR:
1268 mode |= S_IFCHR;
1269 break;
1270 case VLNK:
1271 mode |= S_IFLNK;
1272 break;
1273 case VSOCK:
1274 mode |= S_IFSOCK;
1275 break;
1276 case VFIFO:
1277 mode |= S_IFIFO;
1278 break;
1279 default:
1280 return (EBADF);
1281 };
1282 sb->st_mode = mode;
1283 sb->st_nlink = vap->va_nlink;
1284 sb->st_uid = vap->va_uid;
1285 sb->st_gid = vap->va_gid;
1286 sb->st_rdev = vap->va_rdev;
1287 if (vap->va_size > OFF_MAX)
1288 return (EOVERFLOW);
1289 sb->st_size = vap->va_size;
1290 sb->st_atim = vap->va_atime;
1291 sb->st_mtim = vap->va_mtime;
1292 sb->st_ctim = vap->va_ctime;
1293 sb->st_birthtim = vap->va_birthtime;
1294
1295 /*
1296 * According to www.opengroup.org, the meaning of st_blksize is
1297 * "a filesystem-specific preferred I/O block size for this
1298 * object. In some filesystem types, this may vary from file
1299 * to file"
1300 * Use miminum/default of PAGE_SIZE (e.g. for VCHR).
1301 */
1302
1303 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize);
1304
1305 sb->st_flags = vap->va_flags;
1306 if (priv_check(td, PRIV_VFS_GENERATION))
1307 sb->st_gen = 0;
1308 else
1309 sb->st_gen = vap->va_gen;
1310
1311 sb->st_blocks = vap->va_bytes / S_BLKSIZE;
1312 return (0);
1313 }
1314
1315 /*
1316 * File table vnode ioctl routine.
1317 */
1318 static int
vn_ioctl(fp,com,data,active_cred,td)1319 vn_ioctl(fp, com, data, active_cred, td)
1320 struct file *fp;
1321 u_long com;
1322 void *data;
1323 struct ucred *active_cred;
1324 struct thread *td;
1325 {
1326 struct vnode *vp = fp->f_vnode;
1327 struct vattr vattr;
1328 int vfslocked;
1329 int error;
1330
1331 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
1332 error = ENOTTY;
1333 switch (vp->v_type) {
1334 case VREG:
1335 case VDIR:
1336 if (com == FIONREAD) {
1337 vn_lock(vp, LK_SHARED | LK_RETRY);
1338 error = VOP_GETATTR(vp, &vattr, active_cred);
1339 VOP_UNLOCK(vp, 0);
1340 if (!error)
1341 *(int *)data = vattr.va_size - fp->f_offset;
1342 } else if (com == FIONBIO || com == FIOASYNC) /* XXX */
1343 error = 0;
1344 else
1345 error = VOP_IOCTL(vp, com, data, fp->f_flag,
1346 active_cred, td);
1347 break;
1348
1349 default:
1350 break;
1351 }
1352 VFS_UNLOCK_GIANT(vfslocked);
1353 return (error);
1354 }
1355
1356 /*
1357 * File table vnode poll routine.
1358 */
1359 static int
vn_poll(fp,events,active_cred,td)1360 vn_poll(fp, events, active_cred, td)
1361 struct file *fp;
1362 int events;
1363 struct ucred *active_cred;
1364 struct thread *td;
1365 {
1366 struct vnode *vp;
1367 int vfslocked;
1368 int error;
1369
1370 vp = fp->f_vnode;
1371 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
1372 #ifdef MAC
1373 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1374 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp);
1375 VOP_UNLOCK(vp, 0);
1376 if (!error)
1377 #endif
1378
1379 error = VOP_POLL(vp, events, fp->f_cred, td);
1380 VFS_UNLOCK_GIANT(vfslocked);
1381 return (error);
1382 }
1383
1384 /*
1385 * Acquire the requested lock and then check for validity. LK_RETRY
1386 * permits vn_lock to return doomed vnodes.
1387 */
1388 int
_vn_lock(struct vnode * vp,int flags,char * file,int line)1389 _vn_lock(struct vnode *vp, int flags, char *file, int line)
1390 {
1391 int error;
1392
1393 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
1394 ("vn_lock called with no locktype."));
1395 do {
1396 #ifdef DEBUG_VFS_LOCKS
1397 KASSERT(vp->v_holdcnt != 0,
1398 ("vn_lock %p: zero hold count", vp));
1399 #endif
1400 error = VOP_LOCK1(vp, flags, file, line);
1401 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */
1402 KASSERT((flags & LK_RETRY) == 0 || error == 0,
1403 ("LK_RETRY set with incompatible flags (0x%x) or an error occured (%d)",
1404 flags, error));
1405 /*
1406 * Callers specify LK_RETRY if they wish to get dead vnodes.
1407 * If RETRY is not set, we return ENOENT instead.
1408 */
1409 if (error == 0 && vp->v_iflag & VI_DOOMED &&
1410 (flags & LK_RETRY) == 0) {
1411 VOP_UNLOCK(vp, 0);
1412 error = ENOENT;
1413 break;
1414 }
1415 } while (flags & LK_RETRY && error != 0);
1416 return (error);
1417 }
1418
1419 /*
1420 * File table vnode close routine.
1421 */
1422 static int
vn_closefile(fp,td)1423 vn_closefile(fp, td)
1424 struct file *fp;
1425 struct thread *td;
1426 {
1427 struct vnode *vp;
1428 struct flock lf;
1429 int vfslocked;
1430 int error;
1431
1432 vp = fp->f_vnode;
1433
1434 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
1435 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) {
1436 lf.l_whence = SEEK_SET;
1437 lf.l_start = 0;
1438 lf.l_len = 0;
1439 lf.l_type = F_UNLCK;
1440 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK);
1441 }
1442
1443 fp->f_ops = &badfileops;
1444
1445 error = vn_close(vp, fp->f_flag, fp->f_cred, td);
1446 VFS_UNLOCK_GIANT(vfslocked);
1447 return (error);
1448 }
1449
1450 /*
1451 * Preparing to start a filesystem write operation. If the operation is
1452 * permitted, then we bump the count of operations in progress and
1453 * proceed. If a suspend request is in progress, we wait until the
1454 * suspension is over, and then proceed.
1455 */
1456 static int
vn_start_write_locked(struct mount * mp,int flags)1457 vn_start_write_locked(struct mount *mp, int flags)
1458 {
1459 int error;
1460
1461 mtx_assert(MNT_MTX(mp), MA_OWNED);
1462 error = 0;
1463
1464 /*
1465 * Check on status of suspension.
1466 */
1467 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 ||
1468 mp->mnt_susp_owner != curthread) {
1469 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1470 if (flags & V_NOWAIT) {
1471 error = EWOULDBLOCK;
1472 goto unlock;
1473 }
1474 error = msleep(&mp->mnt_flag, MNT_MTX(mp),
1475 (PUSER - 1) | (flags & PCATCH), "suspfs", 0);
1476 if (error)
1477 goto unlock;
1478 }
1479 }
1480 if (flags & V_XSLEEP)
1481 goto unlock;
1482 mp->mnt_writeopcount++;
1483 unlock:
1484 if (error != 0 || (flags & V_XSLEEP) != 0)
1485 MNT_REL(mp);
1486 MNT_IUNLOCK(mp);
1487 return (error);
1488 }
1489
1490 int
vn_start_write(vp,mpp,flags)1491 vn_start_write(vp, mpp, flags)
1492 struct vnode *vp;
1493 struct mount **mpp;
1494 int flags;
1495 {
1496 struct mount *mp;
1497 int error;
1498
1499 error = 0;
1500 /*
1501 * If a vnode is provided, get and return the mount point that
1502 * to which it will write.
1503 */
1504 if (vp != NULL) {
1505 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1506 *mpp = NULL;
1507 if (error != EOPNOTSUPP)
1508 return (error);
1509 return (0);
1510 }
1511 }
1512 if ((mp = *mpp) == NULL)
1513 return (0);
1514
1515 /*
1516 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1517 * a vfs_ref().
1518 * As long as a vnode is not provided we need to acquire a
1519 * refcount for the provided mountpoint too, in order to
1520 * emulate a vfs_ref().
1521 */
1522 MNT_ILOCK(mp);
1523 if (vp == NULL)
1524 MNT_REF(mp);
1525
1526 return (vn_start_write_locked(mp, flags));
1527 }
1528
1529 /*
1530 * Secondary suspension. Used by operations such as vop_inactive
1531 * routines that are needed by the higher level functions. These
1532 * are allowed to proceed until all the higher level functions have
1533 * completed (indicated by mnt_writeopcount dropping to zero). At that
1534 * time, these operations are halted until the suspension is over.
1535 */
1536 int
vn_start_secondary_write(vp,mpp,flags)1537 vn_start_secondary_write(vp, mpp, flags)
1538 struct vnode *vp;
1539 struct mount **mpp;
1540 int flags;
1541 {
1542 struct mount *mp;
1543 int error;
1544
1545 retry:
1546 if (vp != NULL) {
1547 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1548 *mpp = NULL;
1549 if (error != EOPNOTSUPP)
1550 return (error);
1551 return (0);
1552 }
1553 }
1554 /*
1555 * If we are not suspended or have not yet reached suspended
1556 * mode, then let the operation proceed.
1557 */
1558 if ((mp = *mpp) == NULL)
1559 return (0);
1560
1561 /*
1562 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1563 * a vfs_ref().
1564 * As long as a vnode is not provided we need to acquire a
1565 * refcount for the provided mountpoint too, in order to
1566 * emulate a vfs_ref().
1567 */
1568 MNT_ILOCK(mp);
1569 if (vp == NULL)
1570 MNT_REF(mp);
1571 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) {
1572 mp->mnt_secondary_writes++;
1573 mp->mnt_secondary_accwrites++;
1574 MNT_IUNLOCK(mp);
1575 return (0);
1576 }
1577 if (flags & V_NOWAIT) {
1578 MNT_REL(mp);
1579 MNT_IUNLOCK(mp);
1580 return (EWOULDBLOCK);
1581 }
1582 /*
1583 * Wait for the suspension to finish.
1584 */
1585 error = msleep(&mp->mnt_flag, MNT_MTX(mp),
1586 (PUSER - 1) | (flags & PCATCH) | PDROP, "suspfs", 0);
1587 vfs_rel(mp);
1588 if (error == 0)
1589 goto retry;
1590 return (error);
1591 }
1592
1593 /*
1594 * Filesystem write operation has completed. If we are suspending and this
1595 * operation is the last one, notify the suspender that the suspension is
1596 * now in effect.
1597 */
1598 void
vn_finished_write(mp)1599 vn_finished_write(mp)
1600 struct mount *mp;
1601 {
1602 if (mp == NULL)
1603 return;
1604 MNT_ILOCK(mp);
1605 MNT_REL(mp);
1606 mp->mnt_writeopcount--;
1607 if (mp->mnt_writeopcount < 0)
1608 panic("vn_finished_write: neg cnt");
1609 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
1610 mp->mnt_writeopcount <= 0)
1611 wakeup(&mp->mnt_writeopcount);
1612 MNT_IUNLOCK(mp);
1613 }
1614
1615
1616 /*
1617 * Filesystem secondary write operation has completed. If we are
1618 * suspending and this operation is the last one, notify the suspender
1619 * that the suspension is now in effect.
1620 */
1621 void
vn_finished_secondary_write(mp)1622 vn_finished_secondary_write(mp)
1623 struct mount *mp;
1624 {
1625 if (mp == NULL)
1626 return;
1627 MNT_ILOCK(mp);
1628 MNT_REL(mp);
1629 mp->mnt_secondary_writes--;
1630 if (mp->mnt_secondary_writes < 0)
1631 panic("vn_finished_secondary_write: neg cnt");
1632 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
1633 mp->mnt_secondary_writes <= 0)
1634 wakeup(&mp->mnt_secondary_writes);
1635 MNT_IUNLOCK(mp);
1636 }
1637
1638
1639
1640 /*
1641 * Request a filesystem to suspend write operations.
1642 */
1643 int
vfs_write_suspend(mp)1644 vfs_write_suspend(mp)
1645 struct mount *mp;
1646 {
1647 int error;
1648
1649 MNT_ILOCK(mp);
1650 if (mp->mnt_susp_owner == curthread) {
1651 MNT_IUNLOCK(mp);
1652 return (EALREADY);
1653 }
1654 while (mp->mnt_kern_flag & MNTK_SUSPEND)
1655 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0);
1656 mp->mnt_kern_flag |= MNTK_SUSPEND;
1657 mp->mnt_susp_owner = curthread;
1658 if (mp->mnt_writeopcount > 0)
1659 (void) msleep(&mp->mnt_writeopcount,
1660 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0);
1661 else
1662 MNT_IUNLOCK(mp);
1663 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0)
1664 vfs_write_resume(mp);
1665 return (error);
1666 }
1667
1668 /*
1669 * Request a filesystem to resume write operations.
1670 */
1671 void
vfs_write_resume_flags(struct mount * mp,int flags)1672 vfs_write_resume_flags(struct mount *mp, int flags)
1673 {
1674
1675 MNT_ILOCK(mp);
1676 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1677 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner"));
1678 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 |
1679 MNTK_SUSPENDED);
1680 mp->mnt_susp_owner = NULL;
1681 wakeup(&mp->mnt_writeopcount);
1682 wakeup(&mp->mnt_flag);
1683 curthread->td_pflags &= ~TDP_IGNSUSP;
1684 if ((flags & VR_START_WRITE) != 0) {
1685 MNT_REF(mp);
1686 mp->mnt_writeopcount++;
1687 }
1688 MNT_IUNLOCK(mp);
1689 if ((flags & VR_NO_SUSPCLR) == 0)
1690 VFS_SUSP_CLEAN(mp);
1691 } else if ((flags & VR_START_WRITE) != 0) {
1692 MNT_REF(mp);
1693 vn_start_write_locked(mp, 0);
1694 } else {
1695 MNT_IUNLOCK(mp);
1696 }
1697 }
1698
1699 void
vfs_write_resume(struct mount * mp)1700 vfs_write_resume(struct mount *mp)
1701 {
1702
1703 vfs_write_resume_flags(mp, 0);
1704 }
1705
1706 /*
1707 * Implement kqueues for files by translating it to vnode operation.
1708 */
1709 static int
vn_kqfilter(struct file * fp,struct knote * kn)1710 vn_kqfilter(struct file *fp, struct knote *kn)
1711 {
1712 int vfslocked;
1713 int error;
1714
1715 vfslocked = VFS_LOCK_GIANT(fp->f_vnode->v_mount);
1716 error = VOP_KQFILTER(fp->f_vnode, kn);
1717 VFS_UNLOCK_GIANT(vfslocked);
1718
1719 return error;
1720 }
1721
1722 /*
1723 * Simplified in-kernel wrapper calls for extended attribute access.
1724 * Both calls pass in a NULL credential, authorizing as "kernel" access.
1725 * Set IO_NODELOCKED in ioflg if the vnode is already locked.
1726 */
1727 int
vn_extattr_get(struct vnode * vp,int ioflg,int attrnamespace,const char * attrname,int * buflen,char * buf,struct thread * td)1728 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace,
1729 const char *attrname, int *buflen, char *buf, struct thread *td)
1730 {
1731 struct uio auio;
1732 struct iovec iov;
1733 int error;
1734
1735 iov.iov_len = *buflen;
1736 iov.iov_base = buf;
1737
1738 auio.uio_iov = &iov;
1739 auio.uio_iovcnt = 1;
1740 auio.uio_rw = UIO_READ;
1741 auio.uio_segflg = UIO_SYSSPACE;
1742 auio.uio_td = td;
1743 auio.uio_offset = 0;
1744 auio.uio_resid = *buflen;
1745
1746 if ((ioflg & IO_NODELOCKED) == 0)
1747 vn_lock(vp, LK_SHARED | LK_RETRY);
1748
1749 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
1750
1751 /* authorize attribute retrieval as kernel */
1752 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL,
1753 td);
1754
1755 if ((ioflg & IO_NODELOCKED) == 0)
1756 VOP_UNLOCK(vp, 0);
1757
1758 if (error == 0) {
1759 *buflen = *buflen - auio.uio_resid;
1760 }
1761
1762 return (error);
1763 }
1764
1765 /*
1766 * XXX failure mode if partially written?
1767 */
1768 int
vn_extattr_set(struct vnode * vp,int ioflg,int attrnamespace,const char * attrname,int buflen,char * buf,struct thread * td)1769 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace,
1770 const char *attrname, int buflen, char *buf, struct thread *td)
1771 {
1772 struct uio auio;
1773 struct iovec iov;
1774 struct mount *mp;
1775 int error;
1776
1777 iov.iov_len = buflen;
1778 iov.iov_base = buf;
1779
1780 auio.uio_iov = &iov;
1781 auio.uio_iovcnt = 1;
1782 auio.uio_rw = UIO_WRITE;
1783 auio.uio_segflg = UIO_SYSSPACE;
1784 auio.uio_td = td;
1785 auio.uio_offset = 0;
1786 auio.uio_resid = buflen;
1787
1788 if ((ioflg & IO_NODELOCKED) == 0) {
1789 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
1790 return (error);
1791 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1792 }
1793
1794 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
1795
1796 /* authorize attribute setting as kernel */
1797 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td);
1798
1799 if ((ioflg & IO_NODELOCKED) == 0) {
1800 vn_finished_write(mp);
1801 VOP_UNLOCK(vp, 0);
1802 }
1803
1804 return (error);
1805 }
1806
1807 int
vn_extattr_rm(struct vnode * vp,int ioflg,int attrnamespace,const char * attrname,struct thread * td)1808 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace,
1809 const char *attrname, struct thread *td)
1810 {
1811 struct mount *mp;
1812 int error;
1813
1814 if ((ioflg & IO_NODELOCKED) == 0) {
1815 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
1816 return (error);
1817 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1818 }
1819
1820 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
1821
1822 /* authorize attribute removal as kernel */
1823 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td);
1824 if (error == EOPNOTSUPP)
1825 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL,
1826 NULL, td);
1827
1828 if ((ioflg & IO_NODELOCKED) == 0) {
1829 vn_finished_write(mp);
1830 VOP_UNLOCK(vp, 0);
1831 }
1832
1833 return (error);
1834 }
1835
1836 int
vn_vget_ino(struct vnode * vp,ino_t ino,int lkflags,struct vnode ** rvp)1837 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp)
1838 {
1839 struct mount *mp;
1840 int ltype, error;
1841
1842 mp = vp->v_mount;
1843 ltype = VOP_ISLOCKED(vp);
1844 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED,
1845 ("vn_vget_ino: vp not locked"));
1846 error = vfs_busy(mp, MBF_NOWAIT);
1847 if (error != 0) {
1848 vfs_ref(mp);
1849 VOP_UNLOCK(vp, 0);
1850 error = vfs_busy(mp, 0);
1851 vn_lock(vp, ltype | LK_RETRY);
1852 vfs_rel(mp);
1853 if (error != 0)
1854 return (ENOENT);
1855 if (vp->v_iflag & VI_DOOMED) {
1856 vfs_unbusy(mp);
1857 return (ENOENT);
1858 }
1859 }
1860 VOP_UNLOCK(vp, 0);
1861 error = VFS_VGET(mp, ino, lkflags, rvp);
1862 vfs_unbusy(mp);
1863 vn_lock(vp, ltype | LK_RETRY);
1864 if (vp->v_iflag & VI_DOOMED) {
1865 if (error == 0)
1866 vput(*rvp);
1867 error = ENOENT;
1868 }
1869 return (error);
1870 }
1871
1872 int
vn_rlimit_fsize(const struct vnode * vp,const struct uio * uio,const struct thread * td)1873 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio,
1874 const struct thread *td)
1875 {
1876
1877 if (vp->v_type != VREG || td == NULL)
1878 return (0);
1879 PROC_LOCK(td->td_proc);
1880 if ((uoff_t)uio->uio_offset + uio->uio_resid >
1881 lim_cur(td->td_proc, RLIMIT_FSIZE)) {
1882 kern_psignal(td->td_proc, SIGXFSZ);
1883 PROC_UNLOCK(td->td_proc);
1884 return (EFBIG);
1885 }
1886 PROC_UNLOCK(td->td_proc);
1887 return (0);
1888 }
1889
1890 int
vn_chmod(struct file * fp,mode_t mode,struct ucred * active_cred,struct thread * td)1891 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
1892 struct thread *td)
1893 {
1894 struct vnode *vp;
1895 int error, vfslocked;
1896
1897 vp = fp->f_vnode;
1898 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
1899 #ifdef AUDIT
1900 vn_lock(vp, LK_SHARED | LK_RETRY);
1901 AUDIT_ARG_VNODE1(vp);
1902 VOP_UNLOCK(vp, 0);
1903 #endif
1904 error = setfmode(td, active_cred, vp, mode);
1905 VFS_UNLOCK_GIANT(vfslocked);
1906 return (error);
1907 }
1908
1909 int
vn_chown(struct file * fp,uid_t uid,gid_t gid,struct ucred * active_cred,struct thread * td)1910 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
1911 struct thread *td)
1912 {
1913 struct vnode *vp;
1914 int error, vfslocked;
1915
1916 vp = fp->f_vnode;
1917 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
1918 #ifdef AUDIT
1919 vn_lock(vp, LK_SHARED | LK_RETRY);
1920 AUDIT_ARG_VNODE1(vp);
1921 VOP_UNLOCK(vp, 0);
1922 #endif
1923 error = setfown(td, active_cred, vp, uid, gid);
1924 VFS_UNLOCK_GIANT(vfslocked);
1925 return (error);
1926 }
1927
1928 void
vn_pages_remove(struct vnode * vp,vm_pindex_t start,vm_pindex_t end)1929 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end)
1930 {
1931 vm_object_t object;
1932
1933 if ((object = vp->v_object) == NULL)
1934 return;
1935 VM_OBJECT_LOCK(object);
1936 vm_object_page_remove(object, start, end, 0);
1937 VM_OBJECT_UNLOCK(object);
1938 }
1939
1940 int
vn_bmap_seekhole(struct vnode * vp,u_long cmd,off_t * off,struct ucred * cred)1941 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred)
1942 {
1943 struct vattr va;
1944 daddr_t bn, bnp;
1945 uint64_t bsize;
1946 off_t noff;
1947 int error;
1948
1949 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
1950 ("Wrong command %lu", cmd));
1951
1952 if (vn_lock(vp, LK_SHARED) != 0)
1953 return (EBADF);
1954 if (vp->v_type != VREG) {
1955 error = ENOTTY;
1956 goto unlock;
1957 }
1958 error = VOP_GETATTR(vp, &va, cred);
1959 if (error != 0)
1960 goto unlock;
1961 noff = *off;
1962 if (noff >= va.va_size) {
1963 error = ENXIO;
1964 goto unlock;
1965 }
1966 bsize = vp->v_mount->mnt_stat.f_iosize;
1967 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize) {
1968 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL);
1969 if (error == EOPNOTSUPP) {
1970 error = ENOTTY;
1971 goto unlock;
1972 }
1973 if ((bnp == -1 && cmd == FIOSEEKHOLE) ||
1974 (bnp != -1 && cmd == FIOSEEKDATA)) {
1975 noff = bn * bsize;
1976 if (noff < *off)
1977 noff = *off;
1978 goto unlock;
1979 }
1980 }
1981 if (noff > va.va_size)
1982 noff = va.va_size;
1983 /* noff == va.va_size. There is an implicit hole at the end of file. */
1984 if (cmd == FIOSEEKDATA)
1985 error = ENXIO;
1986 unlock:
1987 VOP_UNLOCK(vp, 0);
1988 if (error == 0)
1989 *off = noff;
1990 return (error);
1991 }
1992