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.
10 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
11 * Copyright (c) 2013, 2014 The FreeBSD Foundation
13 * Portions of this software were developed by Konstantin Belousov
14 * under sponsorship from the FreeBSD Foundation.
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
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.
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
40 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
46 #include <sys/param.h>
47 #include <sys/systm.h>
50 #include <sys/fcntl.h>
56 #include <sys/limits.h>
59 #include <sys/mount.h>
60 #include <sys/mutex.h>
61 #include <sys/namei.h>
62 #include <sys/vnode.h>
65 #include <sys/filio.h>
66 #include <sys/resourcevar.h>
67 #include <sys/rwlock.h>
69 #include <sys/sysctl.h>
70 #include <sys/ttycom.h>
72 #include <sys/syslog.h>
73 #include <sys/unistd.h>
76 #include <security/audit/audit.h>
77 #include <security/mac/mac_framework.h>
80 #include <vm/vm_extern.h>
82 #include <vm/vm_map.h>
83 #include <vm/vm_object.h>
84 #include <vm/vm_page.h>
85 #include <vm/vnode_pager.h>
87 static fo_rdwr_t vn_read;
88 static fo_rdwr_t vn_write;
89 static fo_rdwr_t vn_io_fault;
90 static fo_truncate_t vn_truncate;
91 static fo_ioctl_t vn_ioctl;
92 static fo_poll_t vn_poll;
93 static fo_kqfilter_t vn_kqfilter;
94 static fo_stat_t vn_statfile;
95 static fo_close_t vn_closefile;
96 static fo_mmap_t vn_mmap;
98 struct fileops vnops = {
99 .fo_read = vn_io_fault,
100 .fo_write = vn_io_fault,
101 .fo_truncate = vn_truncate,
102 .fo_ioctl = vn_ioctl,
104 .fo_kqfilter = vn_kqfilter,
105 .fo_stat = vn_statfile,
106 .fo_close = vn_closefile,
107 .fo_chmod = vn_chmod,
108 .fo_chown = vn_chown,
109 .fo_sendfile = vn_sendfile,
111 .fo_fill_kinfo = vn_fill_kinfo,
113 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE
116 static const int io_hold_cnt = 16;
117 static int vn_io_fault_enable = 1;
118 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW,
119 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance");
120 static int vn_io_fault_prefault = 0;
121 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RW,
122 &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting");
123 static u_long vn_io_faults_cnt;
124 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD,
125 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers");
128 * Returns true if vn_io_fault mode of handling the i/o request should
132 do_vn_io_fault(struct vnode *vp, struct uio *uio)
136 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG &&
137 (mp = vp->v_mount) != NULL &&
138 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable);
142 * Structure used to pass arguments to vn_io_fault1(), to do either
143 * file- or vnode-based I/O calls.
145 struct vn_io_fault_args {
153 struct fop_args_tag {
157 struct vop_args_tag {
163 static int vn_io_fault1(struct vnode *vp, struct uio *uio,
164 struct vn_io_fault_args *args, struct thread *td);
167 vn_open(ndp, flagp, cmode, fp)
168 struct nameidata *ndp;
172 struct thread *td = ndp->ni_cnd.cn_thread;
174 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp));
178 * Common code for vnode open operations via a name lookup.
179 * Lookup the vnode and invoke VOP_CREATE if needed.
180 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
182 * Note that this does NOT free nameidata for the successful case,
183 * due to the NDINIT being done elsewhere.
186 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags,
187 struct ucred *cred, struct file *fp)
191 struct thread *td = ndp->ni_cnd.cn_thread;
193 struct vattr *vap = &vat;
198 if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT |
199 O_EXCL | O_DIRECTORY))
201 else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) {
202 ndp->ni_cnd.cn_nameiop = CREATE;
204 * Set NOCACHE to avoid flushing the cache when
205 * rolling in many files at once.
207 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF | NOCACHE;
208 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
209 ndp->ni_cnd.cn_flags |= FOLLOW;
210 if (!(vn_open_flags & VN_OPEN_NOAUDIT))
211 ndp->ni_cnd.cn_flags |= AUDITVNODE1;
212 if (vn_open_flags & VN_OPEN_NOCAPCHECK)
213 ndp->ni_cnd.cn_flags |= NOCAPCHECK;
215 if ((error = namei(ndp)) != 0)
217 if (ndp->ni_vp == NULL) {
220 vap->va_mode = cmode;
222 vap->va_vaflags |= VA_EXCLUSIVE;
223 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) {
224 NDFREE(ndp, NDF_ONLY_PNBUF);
226 if ((error = vn_start_write(NULL, &mp,
227 V_XSLEEP | PCATCH)) != 0)
231 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0)
232 ndp->ni_cnd.cn_flags |= MAKEENTRY;
234 error = mac_vnode_check_create(cred, ndp->ni_dvp,
238 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
241 vn_finished_write(mp);
243 NDFREE(ndp, NDF_ONLY_PNBUF);
249 if (ndp->ni_dvp == ndp->ni_vp)
255 if (fmode & O_EXCL) {
262 ndp->ni_cnd.cn_nameiop = LOOKUP;
263 ndp->ni_cnd.cn_flags = ISOPEN |
264 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF;
265 if (!(fmode & FWRITE))
266 ndp->ni_cnd.cn_flags |= LOCKSHARED;
267 if (!(vn_open_flags & VN_OPEN_NOAUDIT))
268 ndp->ni_cnd.cn_flags |= AUDITVNODE1;
269 if (vn_open_flags & VN_OPEN_NOCAPCHECK)
270 ndp->ni_cnd.cn_flags |= NOCAPCHECK;
271 if ((error = namei(ndp)) != 0)
275 error = vn_open_vnode(vp, fmode, cred, td, fp);
281 NDFREE(ndp, NDF_ONLY_PNBUF);
289 * Common code for vnode open operations once a vnode is located.
290 * Check permissions, and call the VOP_OPEN routine.
293 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred,
294 struct thread *td, struct file *fp)
299 int error, have_flock, lock_flags, type;
301 if (vp->v_type == VLNK)
303 if (vp->v_type == VSOCK)
305 if (vp->v_type != VDIR && fmode & O_DIRECTORY)
308 if (fmode & (FWRITE | O_TRUNC)) {
309 if (vp->v_type == VDIR)
317 if ((fmode & O_APPEND) && (fmode & FWRITE))
322 if (fmode & O_VERIFY)
324 error = mac_vnode_check_open(cred, vp, accmode);
328 accmode &= ~(VCREAT | VVERIFY);
330 if ((fmode & O_CREAT) == 0) {
331 if (accmode & VWRITE) {
332 error = vn_writechk(vp);
337 error = VOP_ACCESS(vp, accmode, cred, td);
342 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
343 vn_lock(vp, LK_UPGRADE | LK_RETRY);
344 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0)
347 if (fmode & (O_EXLOCK | O_SHLOCK)) {
348 KASSERT(fp != NULL, ("open with flock requires fp"));
349 lock_flags = VOP_ISLOCKED(vp);
351 lf.l_whence = SEEK_SET;
354 if (fmode & O_EXLOCK)
359 if ((fmode & FNONBLOCK) == 0)
361 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type);
362 have_flock = (error == 0);
363 vn_lock(vp, lock_flags | LK_RETRY);
364 if (error == 0 && vp->v_iflag & VI_DOOMED)
367 * Another thread might have used this vnode as an
368 * executable while the vnode lock was dropped.
369 * Ensure the vnode is still able to be opened for
370 * writing after the lock has been obtained.
372 if (error == 0 && accmode & VWRITE)
373 error = vn_writechk(vp);
377 lf.l_whence = SEEK_SET;
381 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf,
384 vn_start_write(vp, &mp, V_WAIT);
385 vn_lock(vp, lock_flags | LK_RETRY);
386 (void)VOP_CLOSE(vp, fmode, cred, td);
387 vn_finished_write(mp);
388 /* Prevent second close from fdrop()->vn_close(). */
390 fp->f_ops= &badfileops;
393 fp->f_flag |= FHASLOCK;
395 if (fmode & FWRITE) {
396 VOP_ADD_WRITECOUNT(vp, 1);
397 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
398 __func__, vp, vp->v_writecount);
400 ASSERT_VOP_LOCKED(vp, "vn_open_vnode");
405 * Check for write permissions on the specified vnode.
406 * Prototype text segments cannot be written.
410 register struct vnode *vp;
413 ASSERT_VOP_LOCKED(vp, "vn_writechk");
415 * If there's shared text associated with
416 * the vnode, try to free it up once. If
417 * we fail, we can't allow writing.
429 vn_close(vp, flags, file_cred, td)
430 register struct vnode *vp;
432 struct ucred *file_cred;
436 int error, lock_flags;
438 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 &&
439 MNT_EXTENDED_SHARED(vp->v_mount))
440 lock_flags = LK_SHARED;
442 lock_flags = LK_EXCLUSIVE;
444 vn_start_write(vp, &mp, V_WAIT);
445 vn_lock(vp, lock_flags | LK_RETRY);
446 if (flags & FWRITE) {
447 VNASSERT(vp->v_writecount > 0, vp,
448 ("vn_close: negative writecount"));
449 VOP_ADD_WRITECOUNT(vp, -1);
450 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
451 __func__, vp, vp->v_writecount);
453 error = VOP_CLOSE(vp, flags, file_cred, td);
455 vn_finished_write(mp);
460 * Heuristic to detect sequential operation.
463 sequential_heuristic(struct uio *uio, struct file *fp)
466 ASSERT_VOP_LOCKED(fp->f_vnode, __func__);
467 if (fp->f_flag & FRDAHEAD)
468 return (fp->f_seqcount << IO_SEQSHIFT);
471 * Offset 0 is handled specially. open() sets f_seqcount to 1 so
472 * that the first I/O is normally considered to be slightly
473 * sequential. Seeking to offset 0 doesn't change sequentiality
474 * unless previous seeks have reduced f_seqcount to 0, in which
475 * case offset 0 is not special.
477 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) ||
478 uio->uio_offset == fp->f_nextoff) {
480 * f_seqcount is in units of fixed-size blocks so that it
481 * depends mainly on the amount of sequential I/O and not
482 * much on the number of sequential I/O's. The fixed size
483 * of 16384 is hard-coded here since it is (not quite) just
484 * a magic size that works well here. This size is more
485 * closely related to the best I/O size for real disks than
486 * to any block size used by software.
488 fp->f_seqcount += howmany(uio->uio_resid, 16384);
489 if (fp->f_seqcount > IO_SEQMAX)
490 fp->f_seqcount = IO_SEQMAX;
491 return (fp->f_seqcount << IO_SEQSHIFT);
494 /* Not sequential. Quickly draw-down sequentiality. */
495 if (fp->f_seqcount > 1)
503 * Package up an I/O request on a vnode into a uio and do it.
506 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset,
507 enum uio_seg segflg, int ioflg, struct ucred *active_cred,
508 struct ucred *file_cred, ssize_t *aresid, struct thread *td)
515 struct vn_io_fault_args args;
516 int error, lock_flags;
518 auio.uio_iov = &aiov;
520 aiov.iov_base = base;
522 auio.uio_resid = len;
523 auio.uio_offset = offset;
524 auio.uio_segflg = segflg;
529 if ((ioflg & IO_NODELOCKED) == 0) {
530 if ((ioflg & IO_RANGELOCKED) == 0) {
531 if (rw == UIO_READ) {
532 rl_cookie = vn_rangelock_rlock(vp, offset,
535 rl_cookie = vn_rangelock_wlock(vp, offset,
541 if (rw == UIO_WRITE) {
542 if (vp->v_type != VCHR &&
543 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH))
546 if (MNT_SHARED_WRITES(mp) ||
547 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount)))
548 lock_flags = LK_SHARED;
550 lock_flags = LK_EXCLUSIVE;
552 lock_flags = LK_SHARED;
553 vn_lock(vp, lock_flags | LK_RETRY);
557 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
559 if ((ioflg & IO_NOMACCHECK) == 0) {
561 error = mac_vnode_check_read(active_cred, file_cred,
564 error = mac_vnode_check_write(active_cred, file_cred,
569 if (file_cred != NULL)
573 if (do_vn_io_fault(vp, &auio)) {
574 args.kind = VN_IO_FAULT_VOP;
577 args.args.vop_args.vp = vp;
578 error = vn_io_fault1(vp, &auio, &args, td);
579 } else if (rw == UIO_READ) {
580 error = VOP_READ(vp, &auio, ioflg, cred);
581 } else /* if (rw == UIO_WRITE) */ {
582 error = VOP_WRITE(vp, &auio, ioflg, cred);
586 *aresid = auio.uio_resid;
588 if (auio.uio_resid && error == 0)
590 if ((ioflg & IO_NODELOCKED) == 0) {
593 vn_finished_write(mp);
596 if (rl_cookie != NULL)
597 vn_rangelock_unlock(vp, rl_cookie);
602 * Package up an I/O request on a vnode into a uio and do it. The I/O
603 * request is split up into smaller chunks and we try to avoid saturating
604 * the buffer cache while potentially holding a vnode locked, so we
605 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield()
606 * to give other processes a chance to lock the vnode (either other processes
607 * core'ing the same binary, or unrelated processes scanning the directory).
610 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred,
611 file_cred, aresid, td)
619 struct ucred *active_cred;
620 struct ucred *file_cred;
631 * Force `offset' to a multiple of MAXBSIZE except possibly
632 * for the first chunk, so that filesystems only need to
633 * write full blocks except possibly for the first and last
636 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE;
640 if (rw != UIO_READ && vp->v_type == VREG)
643 error = vn_rdwr(rw, vp, base, chunk, offset, segflg,
644 ioflg, active_cred, file_cred, &iaresid, td);
645 len -= chunk; /* aresid calc already includes length */
649 base = (char *)base + chunk;
650 kern_yield(PRI_USER);
653 *aresid = len + iaresid;
658 foffset_lock(struct file *fp, int flags)
663 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
665 #if OFF_MAX <= LONG_MAX
667 * Caller only wants the current f_offset value. Assume that
668 * the long and shorter integer types reads are atomic.
670 if ((flags & FOF_NOLOCK) != 0)
671 return (fp->f_offset);
675 * According to McKusick the vn lock was protecting f_offset here.
676 * It is now protected by the FOFFSET_LOCKED flag.
678 mtxp = mtx_pool_find(mtxpool_sleep, fp);
680 if ((flags & FOF_NOLOCK) == 0) {
681 while (fp->f_vnread_flags & FOFFSET_LOCKED) {
682 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING;
683 msleep(&fp->f_vnread_flags, mtxp, PUSER -1,
686 fp->f_vnread_flags |= FOFFSET_LOCKED;
694 foffset_unlock(struct file *fp, off_t val, int flags)
698 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
700 #if OFF_MAX <= LONG_MAX
701 if ((flags & FOF_NOLOCK) != 0) {
702 if ((flags & FOF_NOUPDATE) == 0)
704 if ((flags & FOF_NEXTOFF) != 0)
710 mtxp = mtx_pool_find(mtxpool_sleep, fp);
712 if ((flags & FOF_NOUPDATE) == 0)
714 if ((flags & FOF_NEXTOFF) != 0)
716 if ((flags & FOF_NOLOCK) == 0) {
717 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0,
718 ("Lost FOFFSET_LOCKED"));
719 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING)
720 wakeup(&fp->f_vnread_flags);
721 fp->f_vnread_flags = 0;
727 foffset_lock_uio(struct file *fp, struct uio *uio, int flags)
730 if ((flags & FOF_OFFSET) == 0)
731 uio->uio_offset = foffset_lock(fp, flags);
735 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags)
738 if ((flags & FOF_OFFSET) == 0)
739 foffset_unlock(fp, uio->uio_offset, flags);
743 get_advice(struct file *fp, struct uio *uio)
748 ret = POSIX_FADV_NORMAL;
749 if (fp->f_advice == NULL)
752 mtxp = mtx_pool_find(mtxpool_sleep, fp);
754 if (uio->uio_offset >= fp->f_advice->fa_start &&
755 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end)
756 ret = fp->f_advice->fa_advice;
762 * File table vnode read routine.
765 vn_read(fp, uio, active_cred, flags, td)
768 struct ucred *active_cred;
776 off_t offset, start, end;
778 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
780 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
783 if (fp->f_flag & FNONBLOCK)
785 if (fp->f_flag & O_DIRECT)
787 advice = get_advice(fp, uio);
788 vn_lock(vp, LK_SHARED | LK_RETRY);
791 case POSIX_FADV_NORMAL:
792 case POSIX_FADV_SEQUENTIAL:
793 case POSIX_FADV_NOREUSE:
794 ioflag |= sequential_heuristic(uio, fp);
796 case POSIX_FADV_RANDOM:
797 /* Disable read-ahead for random I/O. */
800 offset = uio->uio_offset;
803 error = mac_vnode_check_read(active_cred, fp->f_cred, vp);
806 error = VOP_READ(vp, uio, ioflag, fp->f_cred);
807 fp->f_nextoff = uio->uio_offset;
809 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
810 offset != uio->uio_offset) {
812 * Use POSIX_FADV_DONTNEED to flush clean pages and
813 * buffers for the backing file after a
814 * POSIX_FADV_NOREUSE read(2). To optimize the common
815 * case of using POSIX_FADV_NOREUSE with sequential
816 * access, track the previous implicit DONTNEED
817 * request and grow this request to include the
818 * current read(2) in addition to the previous
819 * DONTNEED. With purely sequential access this will
820 * cause the DONTNEED requests to continously grow to
821 * cover all of the previously read regions of the
822 * file. This allows filesystem blocks that are
823 * accessed by multiple calls to read(2) to be flushed
824 * once the last read(2) finishes.
827 end = uio->uio_offset - 1;
828 mtxp = mtx_pool_find(mtxpool_sleep, fp);
830 if (fp->f_advice != NULL &&
831 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) {
832 if (start != 0 && fp->f_advice->fa_prevend + 1 == start)
833 start = fp->f_advice->fa_prevstart;
834 else if (fp->f_advice->fa_prevstart != 0 &&
835 fp->f_advice->fa_prevstart == end + 1)
836 end = fp->f_advice->fa_prevend;
837 fp->f_advice->fa_prevstart = start;
838 fp->f_advice->fa_prevend = end;
841 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED);
847 * File table vnode write routine.
850 vn_write(fp, uio, active_cred, flags, td)
853 struct ucred *active_cred;
860 int error, ioflag, lock_flags;
862 off_t offset, start, end;
864 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
866 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
868 if (vp->v_type == VREG)
871 if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
873 if (fp->f_flag & FNONBLOCK)
875 if (fp->f_flag & O_DIRECT)
877 if ((fp->f_flag & O_FSYNC) ||
878 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
881 if (vp->v_type != VCHR &&
882 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
885 advice = get_advice(fp, uio);
887 if (MNT_SHARED_WRITES(mp) ||
888 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) {
889 lock_flags = LK_SHARED;
891 lock_flags = LK_EXCLUSIVE;
894 vn_lock(vp, lock_flags | LK_RETRY);
896 case POSIX_FADV_NORMAL:
897 case POSIX_FADV_SEQUENTIAL:
898 case POSIX_FADV_NOREUSE:
899 ioflag |= sequential_heuristic(uio, fp);
901 case POSIX_FADV_RANDOM:
902 /* XXX: Is this correct? */
905 offset = uio->uio_offset;
908 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
911 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred);
912 fp->f_nextoff = uio->uio_offset;
914 if (vp->v_type != VCHR)
915 vn_finished_write(mp);
916 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
917 offset != uio->uio_offset) {
919 * Use POSIX_FADV_DONTNEED to flush clean pages and
920 * buffers for the backing file after a
921 * POSIX_FADV_NOREUSE write(2). To optimize the
922 * common case of using POSIX_FADV_NOREUSE with
923 * sequential access, track the previous implicit
924 * DONTNEED request and grow this request to include
925 * the current write(2) in addition to the previous
926 * DONTNEED. With purely sequential access this will
927 * cause the DONTNEED requests to continously grow to
928 * cover all of the previously written regions of the
931 * Note that the blocks just written are almost
932 * certainly still dirty, so this only works when
933 * VOP_ADVISE() calls from subsequent writes push out
934 * the data written by this write(2) once the backing
935 * buffers are clean. However, as compared to forcing
936 * IO_DIRECT, this gives much saner behavior. Write
937 * clustering is still allowed, and clean pages are
938 * merely moved to the cache page queue rather than
939 * outright thrown away. This means a subsequent
940 * read(2) can still avoid hitting the disk if the
941 * pages have not been reclaimed.
943 * This does make POSIX_FADV_NOREUSE largely useless
944 * with non-sequential access. However, sequential
945 * access is the more common use case and the flag is
949 end = uio->uio_offset - 1;
950 mtxp = mtx_pool_find(mtxpool_sleep, fp);
952 if (fp->f_advice != NULL &&
953 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) {
954 if (start != 0 && fp->f_advice->fa_prevend + 1 == start)
955 start = fp->f_advice->fa_prevstart;
956 else if (fp->f_advice->fa_prevstart != 0 &&
957 fp->f_advice->fa_prevstart == end + 1)
958 end = fp->f_advice->fa_prevend;
959 fp->f_advice->fa_prevstart = start;
960 fp->f_advice->fa_prevend = end;
963 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED);
971 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to
972 * prevent the following deadlock:
974 * Assume that the thread A reads from the vnode vp1 into userspace
975 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is
976 * currently not resident, then system ends up with the call chain
977 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] ->
978 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2)
979 * which establishes lock order vp1->vn_lock, then vp2->vn_lock.
980 * If, at the same time, thread B reads from vnode vp2 into buffer buf2
981 * backed by the pages of vnode vp1, and some page in buf2 is not
982 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock.
984 * To prevent the lock order reversal and deadlock, vn_io_fault() does
985 * not allow page faults to happen during VOP_READ() or VOP_WRITE().
986 * Instead, it first tries to do the whole range i/o with pagefaults
987 * disabled. If all pages in the i/o buffer are resident and mapped,
988 * VOP will succeed (ignoring the genuine filesystem errors).
989 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do
990 * i/o in chunks, with all pages in the chunk prefaulted and held
991 * using vm_fault_quick_hold_pages().
993 * Filesystems using this deadlock avoidance scheme should use the
994 * array of the held pages from uio, saved in the curthread->td_ma,
995 * instead of doing uiomove(). A helper function
996 * vn_io_fault_uiomove() converts uiomove request into
997 * uiomove_fromphys() over td_ma array.
999 * Since vnode locks do not cover the whole i/o anymore, rangelocks
1000 * make the current i/o request atomic with respect to other i/os and
1005 * Decode vn_io_fault_args and perform the corresponding i/o.
1008 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio,
1012 switch (args->kind) {
1013 case VN_IO_FAULT_FOP:
1014 return ((args->args.fop_args.doio)(args->args.fop_args.fp,
1015 uio, args->cred, args->flags, td));
1016 case VN_IO_FAULT_VOP:
1017 if (uio->uio_rw == UIO_READ) {
1018 return (VOP_READ(args->args.vop_args.vp, uio,
1019 args->flags, args->cred));
1020 } else if (uio->uio_rw == UIO_WRITE) {
1021 return (VOP_WRITE(args->args.vop_args.vp, uio,
1022 args->flags, args->cred));
1026 panic("vn_io_fault_doio: unknown kind of io %d %d", args->kind,
1031 vn_io_fault_touch(char *base, const struct uio *uio)
1036 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1))
1042 vn_io_fault_prefault_user(const struct uio *uio)
1045 const struct iovec *iov;
1050 KASSERT(uio->uio_segflg == UIO_USERSPACE,
1051 ("vn_io_fault_prefault userspace"));
1055 resid = uio->uio_resid;
1056 base = iov->iov_base;
1059 error = vn_io_fault_touch(base, uio);
1062 if (len < PAGE_SIZE) {
1064 error = vn_io_fault_touch(base + len - 1, uio);
1069 if (++i >= uio->uio_iovcnt)
1071 iov = uio->uio_iov + i;
1072 base = iov->iov_base;
1084 * Common code for vn_io_fault(), agnostic to the kind of i/o request.
1085 * Uses vn_io_fault_doio() to make the call to an actual i/o function.
1086 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request
1087 * into args and call vn_io_fault1() to handle faults during the user
1088 * mode buffer accesses.
1091 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args,
1094 vm_page_t ma[io_hold_cnt + 2];
1095 struct uio *uio_clone, short_uio;
1096 struct iovec short_iovec[1];
1097 vm_page_t *prev_td_ma;
1099 vm_offset_t addr, end;
1102 int error, cnt, save, saveheld, prev_td_ma_cnt;
1104 if (vn_io_fault_prefault) {
1105 error = vn_io_fault_prefault_user(uio);
1107 return (error); /* Or ignore ? */
1110 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ;
1113 * The UFS follows IO_UNIT directive and replays back both
1114 * uio_offset and uio_resid if an error is encountered during the
1115 * operation. But, since the iovec may be already advanced,
1116 * uio is still in an inconsistent state.
1118 * Cache a copy of the original uio, which is advanced to the redo
1119 * point using UIO_NOCOPY below.
1121 uio_clone = cloneuio(uio);
1122 resid = uio->uio_resid;
1124 short_uio.uio_segflg = UIO_USERSPACE;
1125 short_uio.uio_rw = uio->uio_rw;
1126 short_uio.uio_td = uio->uio_td;
1128 save = vm_fault_disable_pagefaults();
1129 error = vn_io_fault_doio(args, uio, td);
1130 if (error != EFAULT)
1133 atomic_add_long(&vn_io_faults_cnt, 1);
1134 uio_clone->uio_segflg = UIO_NOCOPY;
1135 uiomove(NULL, resid - uio->uio_resid, uio_clone);
1136 uio_clone->uio_segflg = uio->uio_segflg;
1138 saveheld = curthread_pflags_set(TDP_UIOHELD);
1139 prev_td_ma = td->td_ma;
1140 prev_td_ma_cnt = td->td_ma_cnt;
1142 while (uio_clone->uio_resid != 0) {
1143 len = uio_clone->uio_iov->iov_len;
1145 KASSERT(uio_clone->uio_iovcnt >= 1,
1146 ("iovcnt underflow"));
1147 uio_clone->uio_iov++;
1148 uio_clone->uio_iovcnt--;
1151 if (len > io_hold_cnt * PAGE_SIZE)
1152 len = io_hold_cnt * PAGE_SIZE;
1153 addr = (uintptr_t)uio_clone->uio_iov->iov_base;
1154 end = round_page(addr + len);
1159 cnt = atop(end - trunc_page(addr));
1161 * A perfectly misaligned address and length could cause
1162 * both the start and the end of the chunk to use partial
1163 * page. +2 accounts for such a situation.
1165 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map,
1166 addr, len, prot, ma, io_hold_cnt + 2);
1171 short_uio.uio_iov = &short_iovec[0];
1172 short_iovec[0].iov_base = (void *)addr;
1173 short_uio.uio_iovcnt = 1;
1174 short_uio.uio_resid = short_iovec[0].iov_len = len;
1175 short_uio.uio_offset = uio_clone->uio_offset;
1177 td->td_ma_cnt = cnt;
1179 error = vn_io_fault_doio(args, &short_uio, td);
1180 vm_page_unhold_pages(ma, cnt);
1181 adv = len - short_uio.uio_resid;
1183 uio_clone->uio_iov->iov_base =
1184 (char *)uio_clone->uio_iov->iov_base + adv;
1185 uio_clone->uio_iov->iov_len -= adv;
1186 uio_clone->uio_resid -= adv;
1187 uio_clone->uio_offset += adv;
1189 uio->uio_resid -= adv;
1190 uio->uio_offset += adv;
1192 if (error != 0 || adv == 0)
1195 td->td_ma = prev_td_ma;
1196 td->td_ma_cnt = prev_td_ma_cnt;
1197 curthread_pflags_restore(saveheld);
1199 vm_fault_enable_pagefaults(save);
1200 free(uio_clone, M_IOV);
1205 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred,
1206 int flags, struct thread *td)
1211 struct vn_io_fault_args args;
1214 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write;
1216 foffset_lock_uio(fp, uio, flags);
1217 if (do_vn_io_fault(vp, uio)) {
1218 args.kind = VN_IO_FAULT_FOP;
1219 args.args.fop_args.fp = fp;
1220 args.args.fop_args.doio = doio;
1221 args.cred = active_cred;
1222 args.flags = flags | FOF_OFFSET;
1223 if (uio->uio_rw == UIO_READ) {
1224 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset,
1225 uio->uio_offset + uio->uio_resid);
1226 } else if ((fp->f_flag & O_APPEND) != 0 ||
1227 (flags & FOF_OFFSET) == 0) {
1228 /* For appenders, punt and lock the whole range. */
1229 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1231 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset,
1232 uio->uio_offset + uio->uio_resid);
1234 error = vn_io_fault1(vp, uio, &args, td);
1235 vn_rangelock_unlock(vp, rl_cookie);
1237 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td);
1239 foffset_unlock_uio(fp, uio, flags);
1244 * Helper function to perform the requested uiomove operation using
1245 * the held pages for io->uio_iov[0].iov_base buffer instead of
1246 * copyin/copyout. Access to the pages with uiomove_fromphys()
1247 * instead of iov_base prevents page faults that could occur due to
1248 * pmap_collect() invalidating the mapping created by
1249 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or
1250 * object cleanup revoking the write access from page mappings.
1252 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove()
1253 * instead of plain uiomove().
1256 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio)
1258 struct uio transp_uio;
1259 struct iovec transp_iov[1];
1265 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1266 uio->uio_segflg != UIO_USERSPACE)
1267 return (uiomove(data, xfersize, uio));
1269 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1270 transp_iov[0].iov_base = data;
1271 transp_uio.uio_iov = &transp_iov[0];
1272 transp_uio.uio_iovcnt = 1;
1273 if (xfersize > uio->uio_resid)
1274 xfersize = uio->uio_resid;
1275 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize;
1276 transp_uio.uio_offset = 0;
1277 transp_uio.uio_segflg = UIO_SYSSPACE;
1279 * Since transp_iov points to data, and td_ma page array
1280 * corresponds to original uio->uio_iov, we need to invert the
1281 * direction of the i/o operation as passed to
1282 * uiomove_fromphys().
1284 switch (uio->uio_rw) {
1286 transp_uio.uio_rw = UIO_READ;
1289 transp_uio.uio_rw = UIO_WRITE;
1292 transp_uio.uio_td = uio->uio_td;
1293 error = uiomove_fromphys(td->td_ma,
1294 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK,
1295 xfersize, &transp_uio);
1296 adv = xfersize - transp_uio.uio_resid;
1298 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) -
1299 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT);
1301 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1303 td->td_ma_cnt -= pgadv;
1304 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv;
1305 uio->uio_iov->iov_len -= adv;
1306 uio->uio_resid -= adv;
1307 uio->uio_offset += adv;
1312 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize,
1316 vm_offset_t iov_base;
1320 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1321 uio->uio_segflg != UIO_USERSPACE)
1322 return (uiomove_fromphys(ma, offset, xfersize, uio));
1324 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1325 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize;
1326 iov_base = (vm_offset_t)uio->uio_iov->iov_base;
1327 switch (uio->uio_rw) {
1329 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma,
1333 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK,
1337 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT);
1339 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1341 td->td_ma_cnt -= pgadv;
1342 uio->uio_iov->iov_base = (char *)(iov_base + cnt);
1343 uio->uio_iov->iov_len -= cnt;
1344 uio->uio_resid -= cnt;
1345 uio->uio_offset += cnt;
1351 * File table truncate routine.
1354 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred,
1366 * Lock the whole range for truncation. Otherwise split i/o
1367 * might happen partly before and partly after the truncation.
1369 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1370 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
1373 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1374 if (vp->v_type == VDIR) {
1379 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
1383 error = vn_writechk(vp);
1386 vattr.va_size = length;
1387 error = VOP_SETATTR(vp, &vattr, fp->f_cred);
1391 vn_finished_write(mp);
1393 vn_rangelock_unlock(vp, rl_cookie);
1398 * File table vnode stat routine.
1401 vn_statfile(fp, sb, active_cred, td)
1404 struct ucred *active_cred;
1407 struct vnode *vp = fp->f_vnode;
1410 vn_lock(vp, LK_SHARED | LK_RETRY);
1411 error = vn_stat(vp, sb, active_cred, fp->f_cred, td);
1418 * Stat a vnode; implementation for the stat syscall
1421 vn_stat(vp, sb, active_cred, file_cred, td)
1423 register struct stat *sb;
1424 struct ucred *active_cred;
1425 struct ucred *file_cred;
1429 register struct vattr *vap;
1434 error = mac_vnode_check_stat(active_cred, file_cred, vp);
1442 * Initialize defaults for new and unusual fields, so that file
1443 * systems which don't support these fields don't need to know
1446 vap->va_birthtime.tv_sec = -1;
1447 vap->va_birthtime.tv_nsec = 0;
1448 vap->va_fsid = VNOVAL;
1449 vap->va_rdev = NODEV;
1451 error = VOP_GETATTR(vp, vap, active_cred);
1456 * Zero the spare stat fields
1458 bzero(sb, sizeof *sb);
1461 * Copy from vattr table
1463 if (vap->va_fsid != VNOVAL)
1464 sb->st_dev = vap->va_fsid;
1466 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0];
1467 sb->st_ino = vap->va_fileid;
1468 mode = vap->va_mode;
1469 switch (vap->va_type) {
1495 sb->st_nlink = vap->va_nlink;
1496 sb->st_uid = vap->va_uid;
1497 sb->st_gid = vap->va_gid;
1498 sb->st_rdev = vap->va_rdev;
1499 if (vap->va_size > OFF_MAX)
1501 sb->st_size = vap->va_size;
1502 sb->st_atim = vap->va_atime;
1503 sb->st_mtim = vap->va_mtime;
1504 sb->st_ctim = vap->va_ctime;
1505 sb->st_birthtim = vap->va_birthtime;
1508 * According to www.opengroup.org, the meaning of st_blksize is
1509 * "a filesystem-specific preferred I/O block size for this
1510 * object. In some filesystem types, this may vary from file
1512 * Use miminum/default of PAGE_SIZE (e.g. for VCHR).
1515 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize);
1517 sb->st_flags = vap->va_flags;
1518 if (priv_check(td, PRIV_VFS_GENERATION))
1521 sb->st_gen = vap->va_gen;
1523 sb->st_blocks = vap->va_bytes / S_BLKSIZE;
1528 * File table vnode ioctl routine.
1531 vn_ioctl(fp, com, data, active_cred, td)
1535 struct ucred *active_cred;
1543 switch (vp->v_type) {
1548 vn_lock(vp, LK_SHARED | LK_RETRY);
1549 error = VOP_GETATTR(vp, &vattr, active_cred);
1552 *(int *)data = vattr.va_size - fp->f_offset;
1558 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1567 * File table vnode poll routine.
1570 vn_poll(fp, events, active_cred, td)
1573 struct ucred *active_cred;
1581 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1582 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp);
1587 error = VOP_POLL(vp, events, fp->f_cred, td);
1592 * Acquire the requested lock and then check for validity. LK_RETRY
1593 * permits vn_lock to return doomed vnodes.
1596 _vn_lock(struct vnode *vp, int flags, char *file, int line)
1600 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
1601 ("vn_lock called with no locktype."));
1603 #ifdef DEBUG_VFS_LOCKS
1604 KASSERT(vp->v_holdcnt != 0,
1605 ("vn_lock %p: zero hold count", vp));
1607 error = VOP_LOCK1(vp, flags, file, line);
1608 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */
1609 KASSERT((flags & LK_RETRY) == 0 || error == 0,
1610 ("LK_RETRY set with incompatible flags (0x%x) or an error occured (%d)",
1613 * Callers specify LK_RETRY if they wish to get dead vnodes.
1614 * If RETRY is not set, we return ENOENT instead.
1616 if (error == 0 && vp->v_iflag & VI_DOOMED &&
1617 (flags & LK_RETRY) == 0) {
1622 } while (flags & LK_RETRY && error != 0);
1627 * File table vnode close routine.
1630 vn_closefile(fp, td)
1639 fp->f_ops = &badfileops;
1641 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK)
1644 error = vn_close(vp, fp->f_flag, fp->f_cred, td);
1646 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) {
1647 lf.l_whence = SEEK_SET;
1650 lf.l_type = F_UNLCK;
1651 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK);
1658 vn_suspendable(struct mount *mp)
1661 return (mp->mnt_op->vfs_susp_clean != NULL);
1665 * Preparing to start a filesystem write operation. If the operation is
1666 * permitted, then we bump the count of operations in progress and
1667 * proceed. If a suspend request is in progress, we wait until the
1668 * suspension is over, and then proceed.
1671 vn_start_write_locked(struct mount *mp, int flags)
1675 mtx_assert(MNT_MTX(mp), MA_OWNED);
1679 * Check on status of suspension.
1681 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 ||
1682 mp->mnt_susp_owner != curthread) {
1683 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ?
1684 (flags & PCATCH) : 0) | (PUSER - 1);
1685 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1686 if (flags & V_NOWAIT) {
1687 error = EWOULDBLOCK;
1690 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags,
1696 if (flags & V_XSLEEP)
1698 mp->mnt_writeopcount++;
1700 if (error != 0 || (flags & V_XSLEEP) != 0)
1707 vn_start_write(struct vnode *vp, struct mount **mpp, int flags)
1712 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1713 ("V_MNTREF requires mp"));
1717 * If a vnode is provided, get and return the mount point that
1718 * to which it will write.
1721 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1723 if (error != EOPNOTSUPP)
1728 if ((mp = *mpp) == NULL)
1731 if (!vn_suspendable(mp)) {
1732 if (vp != NULL || (flags & V_MNTREF) != 0)
1738 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1740 * As long as a vnode is not provided we need to acquire a
1741 * refcount for the provided mountpoint too, in order to
1742 * emulate a vfs_ref().
1745 if (vp == NULL && (flags & V_MNTREF) == 0)
1748 return (vn_start_write_locked(mp, flags));
1752 * Secondary suspension. Used by operations such as vop_inactive
1753 * routines that are needed by the higher level functions. These
1754 * are allowed to proceed until all the higher level functions have
1755 * completed (indicated by mnt_writeopcount dropping to zero). At that
1756 * time, these operations are halted until the suspension is over.
1759 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags)
1764 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1765 ("V_MNTREF requires mp"));
1769 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1771 if (error != EOPNOTSUPP)
1777 * If we are not suspended or have not yet reached suspended
1778 * mode, then let the operation proceed.
1780 if ((mp = *mpp) == NULL)
1783 if (!vn_suspendable(mp)) {
1784 if (vp != NULL || (flags & V_MNTREF) != 0)
1790 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1792 * As long as a vnode is not provided we need to acquire a
1793 * refcount for the provided mountpoint too, in order to
1794 * emulate a vfs_ref().
1797 if (vp == NULL && (flags & V_MNTREF) == 0)
1799 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) {
1800 mp->mnt_secondary_writes++;
1801 mp->mnt_secondary_accwrites++;
1805 if (flags & V_NOWAIT) {
1808 return (EWOULDBLOCK);
1811 * Wait for the suspension to finish.
1813 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP |
1814 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0),
1823 * Filesystem write operation has completed. If we are suspending and this
1824 * operation is the last one, notify the suspender that the suspension is
1828 vn_finished_write(mp)
1831 if (mp == NULL || !vn_suspendable(mp))
1835 mp->mnt_writeopcount--;
1836 if (mp->mnt_writeopcount < 0)
1837 panic("vn_finished_write: neg cnt");
1838 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
1839 mp->mnt_writeopcount <= 0)
1840 wakeup(&mp->mnt_writeopcount);
1846 * Filesystem secondary write operation has completed. If we are
1847 * suspending and this operation is the last one, notify the suspender
1848 * that the suspension is now in effect.
1851 vn_finished_secondary_write(mp)
1854 if (mp == NULL || !vn_suspendable(mp))
1858 mp->mnt_secondary_writes--;
1859 if (mp->mnt_secondary_writes < 0)
1860 panic("vn_finished_secondary_write: neg cnt");
1861 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
1862 mp->mnt_secondary_writes <= 0)
1863 wakeup(&mp->mnt_secondary_writes);
1870 * Request a filesystem to suspend write operations.
1873 vfs_write_suspend(struct mount *mp, int flags)
1877 MPASS(vn_suspendable(mp));
1880 if (mp->mnt_susp_owner == curthread) {
1884 while (mp->mnt_kern_flag & MNTK_SUSPEND)
1885 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0);
1888 * Unmount holds a write reference on the mount point. If we
1889 * own busy reference and drain for writers, we deadlock with
1890 * the reference draining in the unmount path. Callers of
1891 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if
1892 * vfs_busy() reference is owned and caller is not in the
1895 if ((flags & VS_SKIP_UNMOUNT) != 0 &&
1896 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) {
1901 mp->mnt_kern_flag |= MNTK_SUSPEND;
1902 mp->mnt_susp_owner = curthread;
1903 if (mp->mnt_writeopcount > 0)
1904 (void) msleep(&mp->mnt_writeopcount,
1905 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0);
1908 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0)
1909 vfs_write_resume(mp, 0);
1914 * Request a filesystem to resume write operations.
1917 vfs_write_resume(struct mount *mp, int flags)
1920 MPASS(vn_suspendable(mp));
1923 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1924 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner"));
1925 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 |
1927 mp->mnt_susp_owner = NULL;
1928 wakeup(&mp->mnt_writeopcount);
1929 wakeup(&mp->mnt_flag);
1930 curthread->td_pflags &= ~TDP_IGNSUSP;
1931 if ((flags & VR_START_WRITE) != 0) {
1933 mp->mnt_writeopcount++;
1936 if ((flags & VR_NO_SUSPCLR) == 0)
1938 } else if ((flags & VR_START_WRITE) != 0) {
1940 vn_start_write_locked(mp, 0);
1947 * Helper loop around vfs_write_suspend() for filesystem unmount VFS
1951 vfs_write_suspend_umnt(struct mount *mp)
1955 MPASS(vn_suspendable(mp));
1956 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0,
1957 ("vfs_write_suspend_umnt: recursed"));
1959 /* dounmount() already called vn_start_write(). */
1961 vn_finished_write(mp);
1962 error = vfs_write_suspend(mp, 0);
1964 vn_start_write(NULL, &mp, V_WAIT);
1968 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0)
1971 vn_start_write(NULL, &mp, V_WAIT);
1973 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2);
1974 wakeup(&mp->mnt_flag);
1976 curthread->td_pflags |= TDP_IGNSUSP;
1981 * Implement kqueues for files by translating it to vnode operation.
1984 vn_kqfilter(struct file *fp, struct knote *kn)
1987 return (VOP_KQFILTER(fp->f_vnode, kn));
1991 * Simplified in-kernel wrapper calls for extended attribute access.
1992 * Both calls pass in a NULL credential, authorizing as "kernel" access.
1993 * Set IO_NODELOCKED in ioflg if the vnode is already locked.
1996 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace,
1997 const char *attrname, int *buflen, char *buf, struct thread *td)
2003 iov.iov_len = *buflen;
2006 auio.uio_iov = &iov;
2007 auio.uio_iovcnt = 1;
2008 auio.uio_rw = UIO_READ;
2009 auio.uio_segflg = UIO_SYSSPACE;
2011 auio.uio_offset = 0;
2012 auio.uio_resid = *buflen;
2014 if ((ioflg & IO_NODELOCKED) == 0)
2015 vn_lock(vp, LK_SHARED | LK_RETRY);
2017 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2019 /* authorize attribute retrieval as kernel */
2020 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL,
2023 if ((ioflg & IO_NODELOCKED) == 0)
2027 *buflen = *buflen - auio.uio_resid;
2034 * XXX failure mode if partially written?
2037 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace,
2038 const char *attrname, int buflen, char *buf, struct thread *td)
2045 iov.iov_len = buflen;
2048 auio.uio_iov = &iov;
2049 auio.uio_iovcnt = 1;
2050 auio.uio_rw = UIO_WRITE;
2051 auio.uio_segflg = UIO_SYSSPACE;
2053 auio.uio_offset = 0;
2054 auio.uio_resid = buflen;
2056 if ((ioflg & IO_NODELOCKED) == 0) {
2057 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2059 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2062 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2064 /* authorize attribute setting as kernel */
2065 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td);
2067 if ((ioflg & IO_NODELOCKED) == 0) {
2068 vn_finished_write(mp);
2076 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace,
2077 const char *attrname, struct thread *td)
2082 if ((ioflg & IO_NODELOCKED) == 0) {
2083 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2085 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2088 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2090 /* authorize attribute removal as kernel */
2091 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td);
2092 if (error == EOPNOTSUPP)
2093 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL,
2096 if ((ioflg & IO_NODELOCKED) == 0) {
2097 vn_finished_write(mp);
2105 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags,
2109 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp));
2113 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp)
2116 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino,
2121 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg,
2122 int lkflags, struct vnode **rvp)
2127 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get");
2129 ltype = VOP_ISLOCKED(vp);
2130 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED,
2131 ("vn_vget_ino: vp not locked"));
2132 error = vfs_busy(mp, MBF_NOWAIT);
2136 error = vfs_busy(mp, 0);
2137 vn_lock(vp, ltype | LK_RETRY);
2141 if (vp->v_iflag & VI_DOOMED) {
2147 error = alloc(mp, alloc_arg, lkflags, rvp);
2150 vn_lock(vp, ltype | LK_RETRY);
2151 if (vp->v_iflag & VI_DOOMED) {
2164 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio,
2168 if (vp->v_type != VREG || td == NULL)
2170 if ((uoff_t)uio->uio_offset + uio->uio_resid >
2171 lim_cur(td, RLIMIT_FSIZE)) {
2172 PROC_LOCK(td->td_proc);
2173 kern_psignal(td->td_proc, SIGXFSZ);
2174 PROC_UNLOCK(td->td_proc);
2181 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
2188 vn_lock(vp, LK_SHARED | LK_RETRY);
2189 AUDIT_ARG_VNODE1(vp);
2192 return (setfmode(td, active_cred, vp, mode));
2196 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
2203 vn_lock(vp, LK_SHARED | LK_RETRY);
2204 AUDIT_ARG_VNODE1(vp);
2207 return (setfown(td, active_cred, vp, uid, gid));
2211 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end)
2215 if ((object = vp->v_object) == NULL)
2217 VM_OBJECT_WLOCK(object);
2218 vm_object_page_remove(object, start, end, 0);
2219 VM_OBJECT_WUNLOCK(object);
2223 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred)
2231 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
2232 ("Wrong command %lu", cmd));
2234 if (vn_lock(vp, LK_SHARED) != 0)
2236 if (vp->v_type != VREG) {
2240 error = VOP_GETATTR(vp, &va, cred);
2244 if (noff >= va.va_size) {
2248 bsize = vp->v_mount->mnt_stat.f_iosize;
2249 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize) {
2250 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL);
2251 if (error == EOPNOTSUPP) {
2255 if ((bnp == -1 && cmd == FIOSEEKHOLE) ||
2256 (bnp != -1 && cmd == FIOSEEKDATA)) {
2263 if (noff > va.va_size)
2265 /* noff == va.va_size. There is an implicit hole at the end of file. */
2266 if (cmd == FIOSEEKDATA)
2276 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td)
2281 off_t foffset, size;
2284 cred = td->td_ucred;
2286 foffset = foffset_lock(fp, 0);
2287 noneg = (vp->v_type != VCHR);
2293 (offset > 0 && foffset > OFF_MAX - offset))) {
2300 vn_lock(vp, LK_SHARED | LK_RETRY);
2301 error = VOP_GETATTR(vp, &vattr, cred);
2307 * If the file references a disk device, then fetch
2308 * the media size and use that to determine the ending
2311 if (vattr.va_size == 0 && vp->v_type == VCHR &&
2312 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0)
2313 vattr.va_size = size;
2315 (vattr.va_size > OFF_MAX ||
2316 (offset > 0 && vattr.va_size > OFF_MAX - offset))) {
2320 offset += vattr.va_size;
2325 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td);
2328 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td);
2333 if (error == 0 && noneg && offset < 0)
2337 VFS_KNOTE_UNLOCKED(vp, 0);
2338 td->td_uretoff.tdu_off = offset;
2340 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0);
2345 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred,
2351 * Grant permission if the caller is the owner of the file, or
2352 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on
2353 * on the file. If the time pointer is null, then write
2354 * permission on the file is also sufficient.
2356 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes:
2357 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES
2358 * will be allowed to set the times [..] to the current
2361 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td);
2362 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0)
2363 error = VOP_ACCESS(vp, VWRITE, cred, td);
2368 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
2373 if (fp->f_type == DTYPE_FIFO)
2374 kif->kf_type = KF_TYPE_FIFO;
2376 kif->kf_type = KF_TYPE_VNODE;
2379 FILEDESC_SUNLOCK(fdp);
2380 error = vn_fill_kinfo_vnode(vp, kif);
2382 FILEDESC_SLOCK(fdp);
2387 vn_fill_junk(struct kinfo_file *kif)
2392 * Simulate vn_fullpath returning changing values for a given
2393 * vp during e.g. coredump.
2395 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1;
2396 olen = strlen(kif->kf_path);
2398 strcpy(&kif->kf_path[len - 1], "$");
2400 for (; olen < len; olen++)
2401 strcpy(&kif->kf_path[olen], "A");
2405 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif)
2408 char *fullpath, *freepath;
2411 kif->kf_vnode_type = vntype_to_kinfo(vp->v_type);
2414 error = vn_fullpath(curthread, vp, &fullpath, &freepath);
2416 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
2418 if (freepath != NULL)
2419 free(freepath, M_TEMP);
2421 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path,
2426 * Retrieve vnode attributes.
2428 va.va_fsid = VNOVAL;
2430 vn_lock(vp, LK_SHARED | LK_RETRY);
2431 error = VOP_GETATTR(vp, &va, curthread->td_ucred);
2435 if (va.va_fsid != VNOVAL)
2436 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid;
2438 kif->kf_un.kf_file.kf_file_fsid =
2439 vp->v_mount->mnt_stat.f_fsid.val[0];
2440 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid;
2441 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode);
2442 kif->kf_un.kf_file.kf_file_size = va.va_size;
2443 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev;
2448 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
2449 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
2453 struct pmckern_map_in pkm;
2459 boolean_t writecounted;
2462 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
2463 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
2465 * POSIX shared-memory objects are defined to have
2466 * kernel persistence, and are not defined to support
2467 * read(2)/write(2) -- or even open(2). Thus, we can
2468 * use MAP_ASYNC to trade on-disk coherence for speed.
2469 * The shm_open(3) library routine turns on the FPOSIXSHM
2470 * flag to request this behavior.
2472 if ((fp->f_flag & FPOSIXSHM) != 0)
2473 flags |= MAP_NOSYNC;
2478 * Ensure that file and memory protections are
2479 * compatible. Note that we only worry about
2480 * writability if mapping is shared; in this case,
2481 * current and max prot are dictated by the open file.
2482 * XXX use the vnode instead? Problem is: what
2483 * credentials do we use for determination? What if
2484 * proc does a setuid?
2487 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0)
2488 maxprot = VM_PROT_NONE;
2490 maxprot = VM_PROT_EXECUTE;
2491 if ((fp->f_flag & FREAD) != 0)
2492 maxprot |= VM_PROT_READ;
2493 else if ((prot & VM_PROT_READ) != 0)
2497 * If we are sharing potential changes via MAP_SHARED and we
2498 * are trying to get write permission although we opened it
2499 * without asking for it, bail out.
2501 if ((flags & MAP_SHARED) != 0) {
2502 if ((fp->f_flag & FWRITE) != 0)
2503 maxprot |= VM_PROT_WRITE;
2504 else if ((prot & VM_PROT_WRITE) != 0)
2507 maxprot |= VM_PROT_WRITE;
2508 cap_maxprot |= VM_PROT_WRITE;
2510 maxprot &= cap_maxprot;
2512 writecounted = FALSE;
2513 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp,
2514 &foff, &object, &writecounted);
2517 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
2518 foff, writecounted, td);
2521 * If this mapping was accounted for in the vnode's
2522 * writecount, then undo that now.
2525 vnode_pager_release_writecount(object, 0, size);
2526 vm_object_deallocate(object);
2529 /* Inform hwpmc(4) if an executable is being mapped. */
2530 if (error == 0 && (prot & VM_PROT_EXECUTE) != 0) {
2532 pkm.pm_address = (uintptr_t) addr;
2533 PMC_CALL_HOOK(td, PMC_FN_MMAP, (void *) &pkm);