2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1982, 1986, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
12 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
13 * Copyright (c) 2013, 2014 The FreeBSD Foundation
15 * Portions of this software were developed by Konstantin Belousov
16 * under sponsorship from the FreeBSD Foundation.
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted provided that the following conditions
21 * 1. Redistributions of source code must retain the above copyright
22 * notice, this list of conditions and the following disclaimer.
23 * 2. Redistributions in binary form must reproduce the above copyright
24 * notice, this list of conditions and the following disclaimer in the
25 * documentation and/or other materials provided with the distribution.
26 * 3. Neither the name of the University nor the names of its contributors
27 * may be used to endorse or promote products derived from this software
28 * without specific prior written permission.
30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
42 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
48 #include "opt_hwpmc_hooks.h"
50 #include <sys/param.h>
51 #include <sys/systm.h>
54 #include <sys/fcntl.h>
60 #include <sys/limits.h>
63 #include <sys/mount.h>
64 #include <sys/mutex.h>
65 #include <sys/namei.h>
66 #include <sys/vnode.h>
69 #include <sys/filio.h>
70 #include <sys/resourcevar.h>
71 #include <sys/rwlock.h>
73 #include <sys/sysctl.h>
74 #include <sys/ttycom.h>
76 #include <sys/syslog.h>
77 #include <sys/unistd.h>
80 #include <security/audit/audit.h>
81 #include <security/mac/mac_framework.h>
84 #include <vm/vm_extern.h>
86 #include <vm/vm_map.h>
87 #include <vm/vm_object.h>
88 #include <vm/vm_page.h>
89 #include <vm/vnode_pager.h>
92 #include <sys/pmckern.h>
95 static fo_rdwr_t vn_read;
96 static fo_rdwr_t vn_write;
97 static fo_rdwr_t vn_io_fault;
98 static fo_truncate_t vn_truncate;
99 static fo_ioctl_t vn_ioctl;
100 static fo_poll_t vn_poll;
101 static fo_kqfilter_t vn_kqfilter;
102 static fo_stat_t vn_statfile;
103 static fo_close_t vn_closefile;
104 static fo_mmap_t vn_mmap;
106 struct fileops vnops = {
107 .fo_read = vn_io_fault,
108 .fo_write = vn_io_fault,
109 .fo_truncate = vn_truncate,
110 .fo_ioctl = vn_ioctl,
112 .fo_kqfilter = vn_kqfilter,
113 .fo_stat = vn_statfile,
114 .fo_close = vn_closefile,
115 .fo_chmod = vn_chmod,
116 .fo_chown = vn_chown,
117 .fo_sendfile = vn_sendfile,
119 .fo_fill_kinfo = vn_fill_kinfo,
121 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE
124 static const int io_hold_cnt = 16;
125 static int vn_io_fault_enable = 1;
126 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW,
127 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance");
128 static int vn_io_fault_prefault = 0;
129 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RW,
130 &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting");
131 static u_long vn_io_faults_cnt;
132 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD,
133 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers");
136 * Returns true if vn_io_fault mode of handling the i/o request should
140 do_vn_io_fault(struct vnode *vp, struct uio *uio)
144 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG &&
145 (mp = vp->v_mount) != NULL &&
146 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable);
150 * Structure used to pass arguments to vn_io_fault1(), to do either
151 * file- or vnode-based I/O calls.
153 struct vn_io_fault_args {
161 struct fop_args_tag {
165 struct vop_args_tag {
171 static int vn_io_fault1(struct vnode *vp, struct uio *uio,
172 struct vn_io_fault_args *args, struct thread *td);
175 vn_open(struct nameidata *ndp, int *flagp, int cmode, struct file *fp)
177 struct thread *td = ndp->ni_cnd.cn_thread;
179 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp));
183 * Common code for vnode open operations via a name lookup.
184 * Lookup the vnode and invoke VOP_CREATE if needed.
185 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
187 * Note that this does NOT free nameidata for the successful case,
188 * due to the NDINIT being done elsewhere.
191 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags,
192 struct ucred *cred, struct file *fp)
196 struct thread *td = ndp->ni_cnd.cn_thread;
198 struct vattr *vap = &vat;
203 if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT |
204 O_EXCL | O_DIRECTORY))
206 else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) {
207 ndp->ni_cnd.cn_nameiop = CREATE;
209 * Set NOCACHE to avoid flushing the cache when
210 * rolling in many files at once.
212 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF | NOCACHE;
213 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
214 ndp->ni_cnd.cn_flags |= FOLLOW;
215 if ((fmode & O_BENEATH) != 0)
216 ndp->ni_cnd.cn_flags |= BENEATH;
217 if (!(vn_open_flags & VN_OPEN_NOAUDIT))
218 ndp->ni_cnd.cn_flags |= AUDITVNODE1;
219 if (vn_open_flags & VN_OPEN_NOCAPCHECK)
220 ndp->ni_cnd.cn_flags |= NOCAPCHECK;
222 if ((error = namei(ndp)) != 0)
224 if (ndp->ni_vp == NULL) {
227 vap->va_mode = cmode;
229 vap->va_vaflags |= VA_EXCLUSIVE;
230 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) {
231 NDFREE(ndp, NDF_ONLY_PNBUF);
233 if ((error = vn_start_write(NULL, &mp,
234 V_XSLEEP | PCATCH)) != 0)
238 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0)
239 ndp->ni_cnd.cn_flags |= MAKEENTRY;
241 error = mac_vnode_check_create(cred, ndp->ni_dvp,
245 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
248 vn_finished_write(mp);
250 NDFREE(ndp, NDF_ONLY_PNBUF);
256 if (ndp->ni_dvp == ndp->ni_vp)
262 if (fmode & O_EXCL) {
269 ndp->ni_cnd.cn_nameiop = LOOKUP;
270 ndp->ni_cnd.cn_flags = ISOPEN |
271 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF;
272 if (!(fmode & FWRITE))
273 ndp->ni_cnd.cn_flags |= LOCKSHARED;
274 if ((fmode & O_BENEATH) != 0)
275 ndp->ni_cnd.cn_flags |= BENEATH;
276 if (!(vn_open_flags & VN_OPEN_NOAUDIT))
277 ndp->ni_cnd.cn_flags |= AUDITVNODE1;
278 if (vn_open_flags & VN_OPEN_NOCAPCHECK)
279 ndp->ni_cnd.cn_flags |= NOCAPCHECK;
280 if ((error = namei(ndp)) != 0)
284 error = vn_open_vnode(vp, fmode, cred, td, fp);
290 NDFREE(ndp, NDF_ONLY_PNBUF);
298 vn_open_vnode_advlock(struct vnode *vp, int fmode, struct file *fp)
301 int error, lock_flags, type;
303 ASSERT_VOP_LOCKED(vp, "vn_open_vnode_advlock");
304 if ((fmode & (O_EXLOCK | O_SHLOCK)) == 0)
306 KASSERT(fp != NULL, ("open with flock requires fp"));
307 if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE)
310 lock_flags = VOP_ISLOCKED(vp);
313 lf.l_whence = SEEK_SET;
316 lf.l_type = (fmode & O_EXLOCK) != 0 ? F_WRLCK : F_RDLCK;
318 if ((fmode & FNONBLOCK) == 0)
320 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type);
322 fp->f_flag |= FHASLOCK;
324 vn_lock(vp, lock_flags | LK_RETRY);
325 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0)
331 * Common code for vnode open operations once a vnode is located.
332 * Check permissions, and call the VOP_OPEN routine.
335 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred,
336 struct thread *td, struct file *fp)
341 if (vp->v_type == VLNK)
343 if (vp->v_type == VSOCK)
345 if (vp->v_type != VDIR && fmode & O_DIRECTORY)
348 if (fmode & (FWRITE | O_TRUNC)) {
349 if (vp->v_type == VDIR)
357 if ((fmode & O_APPEND) && (fmode & FWRITE))
362 if (fmode & O_VERIFY)
364 error = mac_vnode_check_open(cred, vp, accmode);
368 accmode &= ~(VCREAT | VVERIFY);
370 if ((fmode & O_CREAT) == 0 && accmode != 0) {
371 error = VOP_ACCESS(vp, accmode, cred, td);
375 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
376 vn_lock(vp, LK_UPGRADE | LK_RETRY);
377 error = VOP_OPEN(vp, fmode, cred, td, fp);
381 error = vn_open_vnode_advlock(vp, fmode, fp);
382 if (error == 0 && (fmode & FWRITE) != 0) {
383 error = VOP_ADD_WRITECOUNT(vp, 1);
385 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
386 __func__, vp, vp->v_writecount);
391 * Error from advlock or VOP_ADD_WRITECOUNT() still requires
392 * calling VOP_CLOSE() to pair with earlier VOP_OPEN().
393 * Arrange for that by having fdrop() to use vn_closefile().
396 fp->f_flag |= FOPENFAILED;
398 if (fp->f_ops == &badfileops) {
399 fp->f_type = DTYPE_VNODE;
405 ASSERT_VOP_LOCKED(vp, "vn_open_vnode");
411 * Check for write permissions on the specified vnode.
412 * Prototype text segments cannot be written.
416 vn_writechk(struct vnode *vp)
419 ASSERT_VOP_LOCKED(vp, "vn_writechk");
421 * If there's shared text associated with
422 * the vnode, try to free it up once. If
423 * we fail, we can't allow writing.
435 vn_close1(struct vnode *vp, int flags, struct ucred *file_cred,
436 struct thread *td, bool keep_ref)
439 int error, lock_flags;
441 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 &&
442 MNT_EXTENDED_SHARED(vp->v_mount))
443 lock_flags = LK_SHARED;
445 lock_flags = LK_EXCLUSIVE;
447 vn_start_write(vp, &mp, V_WAIT);
448 vn_lock(vp, lock_flags | LK_RETRY);
449 AUDIT_ARG_VNODE1(vp);
450 if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) {
451 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
452 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
453 __func__, vp, vp->v_writecount);
455 error = VOP_CLOSE(vp, flags, file_cred, td);
460 vn_finished_write(mp);
465 vn_close(struct vnode *vp, int flags, struct ucred *file_cred,
469 return (vn_close1(vp, flags, file_cred, td, false));
473 * Heuristic to detect sequential operation.
476 sequential_heuristic(struct uio *uio, struct file *fp)
479 ASSERT_VOP_LOCKED(fp->f_vnode, __func__);
480 if (fp->f_flag & FRDAHEAD)
481 return (fp->f_seqcount << IO_SEQSHIFT);
484 * Offset 0 is handled specially. open() sets f_seqcount to 1 so
485 * that the first I/O is normally considered to be slightly
486 * sequential. Seeking to offset 0 doesn't change sequentiality
487 * unless previous seeks have reduced f_seqcount to 0, in which
488 * case offset 0 is not special.
490 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) ||
491 uio->uio_offset == fp->f_nextoff) {
493 * f_seqcount is in units of fixed-size blocks so that it
494 * depends mainly on the amount of sequential I/O and not
495 * much on the number of sequential I/O's. The fixed size
496 * of 16384 is hard-coded here since it is (not quite) just
497 * a magic size that works well here. This size is more
498 * closely related to the best I/O size for real disks than
499 * to any block size used by software.
501 fp->f_seqcount += howmany(uio->uio_resid, 16384);
502 if (fp->f_seqcount > IO_SEQMAX)
503 fp->f_seqcount = IO_SEQMAX;
504 return (fp->f_seqcount << IO_SEQSHIFT);
507 /* Not sequential. Quickly draw-down sequentiality. */
508 if (fp->f_seqcount > 1)
516 * Package up an I/O request on a vnode into a uio and do it.
519 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset,
520 enum uio_seg segflg, int ioflg, struct ucred *active_cred,
521 struct ucred *file_cred, ssize_t *aresid, struct thread *td)
528 struct vn_io_fault_args args;
529 int error, lock_flags;
531 if (offset < 0 && vp->v_type != VCHR)
533 auio.uio_iov = &aiov;
535 aiov.iov_base = base;
537 auio.uio_resid = len;
538 auio.uio_offset = offset;
539 auio.uio_segflg = segflg;
544 if ((ioflg & IO_NODELOCKED) == 0) {
545 if ((ioflg & IO_RANGELOCKED) == 0) {
546 if (rw == UIO_READ) {
547 rl_cookie = vn_rangelock_rlock(vp, offset,
550 rl_cookie = vn_rangelock_wlock(vp, offset,
556 if (rw == UIO_WRITE) {
557 if (vp->v_type != VCHR &&
558 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH))
561 if (MNT_SHARED_WRITES(mp) ||
562 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount)))
563 lock_flags = LK_SHARED;
565 lock_flags = LK_EXCLUSIVE;
567 lock_flags = LK_SHARED;
568 vn_lock(vp, lock_flags | LK_RETRY);
572 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
574 if ((ioflg & IO_NOMACCHECK) == 0) {
576 error = mac_vnode_check_read(active_cred, file_cred,
579 error = mac_vnode_check_write(active_cred, file_cred,
584 if (file_cred != NULL)
588 if (do_vn_io_fault(vp, &auio)) {
589 args.kind = VN_IO_FAULT_VOP;
592 args.args.vop_args.vp = vp;
593 error = vn_io_fault1(vp, &auio, &args, td);
594 } else if (rw == UIO_READ) {
595 error = VOP_READ(vp, &auio, ioflg, cred);
596 } else /* if (rw == UIO_WRITE) */ {
597 error = VOP_WRITE(vp, &auio, ioflg, cred);
601 *aresid = auio.uio_resid;
603 if (auio.uio_resid && error == 0)
605 if ((ioflg & IO_NODELOCKED) == 0) {
608 vn_finished_write(mp);
611 if (rl_cookie != NULL)
612 vn_rangelock_unlock(vp, rl_cookie);
617 * Package up an I/O request on a vnode into a uio and do it. The I/O
618 * request is split up into smaller chunks and we try to avoid saturating
619 * the buffer cache while potentially holding a vnode locked, so we
620 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield()
621 * to give other processes a chance to lock the vnode (either other processes
622 * core'ing the same binary, or unrelated processes scanning the directory).
625 vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, void *base, size_t len,
626 off_t offset, enum uio_seg segflg, int ioflg, struct ucred *active_cred,
627 struct ucred *file_cred, size_t *aresid, struct thread *td)
636 * Force `offset' to a multiple of MAXBSIZE except possibly
637 * for the first chunk, so that filesystems only need to
638 * write full blocks except possibly for the first and last
641 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE;
645 if (rw != UIO_READ && vp->v_type == VREG)
648 error = vn_rdwr(rw, vp, base, chunk, offset, segflg,
649 ioflg, active_cred, file_cred, &iaresid, td);
650 len -= chunk; /* aresid calc already includes length */
654 base = (char *)base + chunk;
655 kern_yield(PRI_USER);
658 *aresid = len + iaresid;
663 foffset_lock(struct file *fp, int flags)
668 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
670 #if OFF_MAX <= LONG_MAX
672 * Caller only wants the current f_offset value. Assume that
673 * the long and shorter integer types reads are atomic.
675 if ((flags & FOF_NOLOCK) != 0)
676 return (fp->f_offset);
680 * According to McKusick the vn lock was protecting f_offset here.
681 * It is now protected by the FOFFSET_LOCKED flag.
683 mtxp = mtx_pool_find(mtxpool_sleep, fp);
685 if ((flags & FOF_NOLOCK) == 0) {
686 while (fp->f_vnread_flags & FOFFSET_LOCKED) {
687 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING;
688 msleep(&fp->f_vnread_flags, mtxp, PUSER -1,
691 fp->f_vnread_flags |= FOFFSET_LOCKED;
699 foffset_unlock(struct file *fp, off_t val, int flags)
703 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
705 #if OFF_MAX <= LONG_MAX
706 if ((flags & FOF_NOLOCK) != 0) {
707 if ((flags & FOF_NOUPDATE) == 0)
709 if ((flags & FOF_NEXTOFF) != 0)
715 mtxp = mtx_pool_find(mtxpool_sleep, fp);
717 if ((flags & FOF_NOUPDATE) == 0)
719 if ((flags & FOF_NEXTOFF) != 0)
721 if ((flags & FOF_NOLOCK) == 0) {
722 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0,
723 ("Lost FOFFSET_LOCKED"));
724 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING)
725 wakeup(&fp->f_vnread_flags);
726 fp->f_vnread_flags = 0;
732 foffset_lock_uio(struct file *fp, struct uio *uio, int flags)
735 if ((flags & FOF_OFFSET) == 0)
736 uio->uio_offset = foffset_lock(fp, flags);
740 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags)
743 if ((flags & FOF_OFFSET) == 0)
744 foffset_unlock(fp, uio->uio_offset, flags);
748 get_advice(struct file *fp, struct uio *uio)
753 ret = POSIX_FADV_NORMAL;
754 if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG)
757 mtxp = mtx_pool_find(mtxpool_sleep, fp);
759 if (fp->f_advice != NULL &&
760 uio->uio_offset >= fp->f_advice->fa_start &&
761 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end)
762 ret = fp->f_advice->fa_advice;
768 * File table vnode read routine.
771 vn_read(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
779 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
781 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
784 if (fp->f_flag & FNONBLOCK)
786 if (fp->f_flag & O_DIRECT)
788 advice = get_advice(fp, uio);
789 vn_lock(vp, LK_SHARED | LK_RETRY);
792 case POSIX_FADV_NORMAL:
793 case POSIX_FADV_SEQUENTIAL:
794 case POSIX_FADV_NOREUSE:
795 ioflag |= sequential_heuristic(uio, fp);
797 case POSIX_FADV_RANDOM:
798 /* Disable read-ahead for random I/O. */
801 orig_offset = uio->uio_offset;
804 error = mac_vnode_check_read(active_cred, fp->f_cred, vp);
807 error = VOP_READ(vp, uio, ioflag, fp->f_cred);
808 fp->f_nextoff = uio->uio_offset;
810 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
811 orig_offset != uio->uio_offset)
813 * Use POSIX_FADV_DONTNEED to flush pages and buffers
814 * for the backing file after a POSIX_FADV_NOREUSE
817 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
818 POSIX_FADV_DONTNEED);
823 * File table vnode write routine.
826 vn_write(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
832 int error, ioflag, lock_flags;
835 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
837 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
839 if (vp->v_type == VREG)
842 if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
844 if (fp->f_flag & FNONBLOCK)
846 if (fp->f_flag & O_DIRECT)
848 if ((fp->f_flag & O_FSYNC) ||
849 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
852 if (vp->v_type != VCHR &&
853 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
856 advice = get_advice(fp, uio);
858 if (MNT_SHARED_WRITES(mp) ||
859 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) {
860 lock_flags = LK_SHARED;
862 lock_flags = LK_EXCLUSIVE;
865 vn_lock(vp, lock_flags | LK_RETRY);
867 case POSIX_FADV_NORMAL:
868 case POSIX_FADV_SEQUENTIAL:
869 case POSIX_FADV_NOREUSE:
870 ioflag |= sequential_heuristic(uio, fp);
872 case POSIX_FADV_RANDOM:
873 /* XXX: Is this correct? */
876 orig_offset = uio->uio_offset;
879 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
882 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred);
883 fp->f_nextoff = uio->uio_offset;
885 if (vp->v_type != VCHR)
886 vn_finished_write(mp);
887 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
888 orig_offset != uio->uio_offset)
890 * Use POSIX_FADV_DONTNEED to flush pages and buffers
891 * for the backing file after a POSIX_FADV_NOREUSE
894 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
895 POSIX_FADV_DONTNEED);
901 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to
902 * prevent the following deadlock:
904 * Assume that the thread A reads from the vnode vp1 into userspace
905 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is
906 * currently not resident, then system ends up with the call chain
907 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] ->
908 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2)
909 * which establishes lock order vp1->vn_lock, then vp2->vn_lock.
910 * If, at the same time, thread B reads from vnode vp2 into buffer buf2
911 * backed by the pages of vnode vp1, and some page in buf2 is not
912 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock.
914 * To prevent the lock order reversal and deadlock, vn_io_fault() does
915 * not allow page faults to happen during VOP_READ() or VOP_WRITE().
916 * Instead, it first tries to do the whole range i/o with pagefaults
917 * disabled. If all pages in the i/o buffer are resident and mapped,
918 * VOP will succeed (ignoring the genuine filesystem errors).
919 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do
920 * i/o in chunks, with all pages in the chunk prefaulted and held
921 * using vm_fault_quick_hold_pages().
923 * Filesystems using this deadlock avoidance scheme should use the
924 * array of the held pages from uio, saved in the curthread->td_ma,
925 * instead of doing uiomove(). A helper function
926 * vn_io_fault_uiomove() converts uiomove request into
927 * uiomove_fromphys() over td_ma array.
929 * Since vnode locks do not cover the whole i/o anymore, rangelocks
930 * make the current i/o request atomic with respect to other i/os and
935 * Decode vn_io_fault_args and perform the corresponding i/o.
938 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio,
944 save = vm_fault_disable_pagefaults();
945 switch (args->kind) {
946 case VN_IO_FAULT_FOP:
947 error = (args->args.fop_args.doio)(args->args.fop_args.fp,
948 uio, args->cred, args->flags, td);
950 case VN_IO_FAULT_VOP:
951 if (uio->uio_rw == UIO_READ) {
952 error = VOP_READ(args->args.vop_args.vp, uio,
953 args->flags, args->cred);
954 } else if (uio->uio_rw == UIO_WRITE) {
955 error = VOP_WRITE(args->args.vop_args.vp, uio,
956 args->flags, args->cred);
960 panic("vn_io_fault_doio: unknown kind of io %d %d",
961 args->kind, uio->uio_rw);
963 vm_fault_enable_pagefaults(save);
968 vn_io_fault_touch(char *base, const struct uio *uio)
973 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1))
979 vn_io_fault_prefault_user(const struct uio *uio)
982 const struct iovec *iov;
987 KASSERT(uio->uio_segflg == UIO_USERSPACE,
988 ("vn_io_fault_prefault userspace"));
992 resid = uio->uio_resid;
993 base = iov->iov_base;
996 error = vn_io_fault_touch(base, uio);
999 if (len < PAGE_SIZE) {
1001 error = vn_io_fault_touch(base + len - 1, uio);
1006 if (++i >= uio->uio_iovcnt)
1008 iov = uio->uio_iov + i;
1009 base = iov->iov_base;
1021 * Common code for vn_io_fault(), agnostic to the kind of i/o request.
1022 * Uses vn_io_fault_doio() to make the call to an actual i/o function.
1023 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request
1024 * into args and call vn_io_fault1() to handle faults during the user
1025 * mode buffer accesses.
1028 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args,
1031 vm_page_t ma[io_hold_cnt + 2];
1032 struct uio *uio_clone, short_uio;
1033 struct iovec short_iovec[1];
1034 vm_page_t *prev_td_ma;
1036 vm_offset_t addr, end;
1039 int error, cnt, saveheld, prev_td_ma_cnt;
1041 if (vn_io_fault_prefault) {
1042 error = vn_io_fault_prefault_user(uio);
1044 return (error); /* Or ignore ? */
1047 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ;
1050 * The UFS follows IO_UNIT directive and replays back both
1051 * uio_offset and uio_resid if an error is encountered during the
1052 * operation. But, since the iovec may be already advanced,
1053 * uio is still in an inconsistent state.
1055 * Cache a copy of the original uio, which is advanced to the redo
1056 * point using UIO_NOCOPY below.
1058 uio_clone = cloneuio(uio);
1059 resid = uio->uio_resid;
1061 short_uio.uio_segflg = UIO_USERSPACE;
1062 short_uio.uio_rw = uio->uio_rw;
1063 short_uio.uio_td = uio->uio_td;
1065 error = vn_io_fault_doio(args, uio, td);
1066 if (error != EFAULT)
1069 atomic_add_long(&vn_io_faults_cnt, 1);
1070 uio_clone->uio_segflg = UIO_NOCOPY;
1071 uiomove(NULL, resid - uio->uio_resid, uio_clone);
1072 uio_clone->uio_segflg = uio->uio_segflg;
1074 saveheld = curthread_pflags_set(TDP_UIOHELD);
1075 prev_td_ma = td->td_ma;
1076 prev_td_ma_cnt = td->td_ma_cnt;
1078 while (uio_clone->uio_resid != 0) {
1079 len = uio_clone->uio_iov->iov_len;
1081 KASSERT(uio_clone->uio_iovcnt >= 1,
1082 ("iovcnt underflow"));
1083 uio_clone->uio_iov++;
1084 uio_clone->uio_iovcnt--;
1087 if (len > io_hold_cnt * PAGE_SIZE)
1088 len = io_hold_cnt * PAGE_SIZE;
1089 addr = (uintptr_t)uio_clone->uio_iov->iov_base;
1090 end = round_page(addr + len);
1095 cnt = atop(end - trunc_page(addr));
1097 * A perfectly misaligned address and length could cause
1098 * both the start and the end of the chunk to use partial
1099 * page. +2 accounts for such a situation.
1101 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map,
1102 addr, len, prot, ma, io_hold_cnt + 2);
1107 short_uio.uio_iov = &short_iovec[0];
1108 short_iovec[0].iov_base = (void *)addr;
1109 short_uio.uio_iovcnt = 1;
1110 short_uio.uio_resid = short_iovec[0].iov_len = len;
1111 short_uio.uio_offset = uio_clone->uio_offset;
1113 td->td_ma_cnt = cnt;
1115 error = vn_io_fault_doio(args, &short_uio, td);
1116 vm_page_unhold_pages(ma, cnt);
1117 adv = len - short_uio.uio_resid;
1119 uio_clone->uio_iov->iov_base =
1120 (char *)uio_clone->uio_iov->iov_base + adv;
1121 uio_clone->uio_iov->iov_len -= adv;
1122 uio_clone->uio_resid -= adv;
1123 uio_clone->uio_offset += adv;
1125 uio->uio_resid -= adv;
1126 uio->uio_offset += adv;
1128 if (error != 0 || adv == 0)
1131 td->td_ma = prev_td_ma;
1132 td->td_ma_cnt = prev_td_ma_cnt;
1133 curthread_pflags_restore(saveheld);
1135 free(uio_clone, M_IOV);
1140 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred,
1141 int flags, struct thread *td)
1146 struct vn_io_fault_args args;
1149 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write;
1151 foffset_lock_uio(fp, uio, flags);
1152 if (do_vn_io_fault(vp, uio)) {
1153 args.kind = VN_IO_FAULT_FOP;
1154 args.args.fop_args.fp = fp;
1155 args.args.fop_args.doio = doio;
1156 args.cred = active_cred;
1157 args.flags = flags | FOF_OFFSET;
1158 if (uio->uio_rw == UIO_READ) {
1159 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset,
1160 uio->uio_offset + uio->uio_resid);
1161 } else if ((fp->f_flag & O_APPEND) != 0 ||
1162 (flags & FOF_OFFSET) == 0) {
1163 /* For appenders, punt and lock the whole range. */
1164 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1166 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset,
1167 uio->uio_offset + uio->uio_resid);
1169 error = vn_io_fault1(vp, uio, &args, td);
1170 vn_rangelock_unlock(vp, rl_cookie);
1172 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td);
1174 foffset_unlock_uio(fp, uio, flags);
1179 * Helper function to perform the requested uiomove operation using
1180 * the held pages for io->uio_iov[0].iov_base buffer instead of
1181 * copyin/copyout. Access to the pages with uiomove_fromphys()
1182 * instead of iov_base prevents page faults that could occur due to
1183 * pmap_collect() invalidating the mapping created by
1184 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or
1185 * object cleanup revoking the write access from page mappings.
1187 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove()
1188 * instead of plain uiomove().
1191 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio)
1193 struct uio transp_uio;
1194 struct iovec transp_iov[1];
1200 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1201 uio->uio_segflg != UIO_USERSPACE)
1202 return (uiomove(data, xfersize, uio));
1204 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1205 transp_iov[0].iov_base = data;
1206 transp_uio.uio_iov = &transp_iov[0];
1207 transp_uio.uio_iovcnt = 1;
1208 if (xfersize > uio->uio_resid)
1209 xfersize = uio->uio_resid;
1210 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize;
1211 transp_uio.uio_offset = 0;
1212 transp_uio.uio_segflg = UIO_SYSSPACE;
1214 * Since transp_iov points to data, and td_ma page array
1215 * corresponds to original uio->uio_iov, we need to invert the
1216 * direction of the i/o operation as passed to
1217 * uiomove_fromphys().
1219 switch (uio->uio_rw) {
1221 transp_uio.uio_rw = UIO_READ;
1224 transp_uio.uio_rw = UIO_WRITE;
1227 transp_uio.uio_td = uio->uio_td;
1228 error = uiomove_fromphys(td->td_ma,
1229 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK,
1230 xfersize, &transp_uio);
1231 adv = xfersize - transp_uio.uio_resid;
1233 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) -
1234 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT);
1236 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1238 td->td_ma_cnt -= pgadv;
1239 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv;
1240 uio->uio_iov->iov_len -= adv;
1241 uio->uio_resid -= adv;
1242 uio->uio_offset += adv;
1247 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize,
1251 vm_offset_t iov_base;
1255 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1256 uio->uio_segflg != UIO_USERSPACE)
1257 return (uiomove_fromphys(ma, offset, xfersize, uio));
1259 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1260 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize;
1261 iov_base = (vm_offset_t)uio->uio_iov->iov_base;
1262 switch (uio->uio_rw) {
1264 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma,
1268 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK,
1272 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT);
1274 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1276 td->td_ma_cnt -= pgadv;
1277 uio->uio_iov->iov_base = (char *)(iov_base + cnt);
1278 uio->uio_iov->iov_len -= cnt;
1279 uio->uio_resid -= cnt;
1280 uio->uio_offset += cnt;
1286 * File table truncate routine.
1289 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred,
1301 * Lock the whole range for truncation. Otherwise split i/o
1302 * might happen partly before and partly after the truncation.
1304 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1305 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
1308 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1309 AUDIT_ARG_VNODE1(vp);
1310 if (vp->v_type == VDIR) {
1315 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
1319 error = VOP_ADD_WRITECOUNT(vp, 1);
1322 vattr.va_size = length;
1323 if ((fp->f_flag & O_FSYNC) != 0)
1324 vattr.va_vaflags |= VA_SYNC;
1325 error = VOP_SETATTR(vp, &vattr, fp->f_cred);
1326 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
1330 vn_finished_write(mp);
1332 vn_rangelock_unlock(vp, rl_cookie);
1337 * File table vnode stat routine.
1340 vn_statfile(struct file *fp, struct stat *sb, struct ucred *active_cred,
1343 struct vnode *vp = fp->f_vnode;
1346 vn_lock(vp, LK_SHARED | LK_RETRY);
1347 error = vn_stat(vp, sb, active_cred, fp->f_cred, td);
1354 * Stat a vnode; implementation for the stat syscall
1357 vn_stat(struct vnode *vp, struct stat *sb, struct ucred *active_cred,
1358 struct ucred *file_cred, struct thread *td)
1365 AUDIT_ARG_VNODE1(vp);
1367 error = mac_vnode_check_stat(active_cred, file_cred, vp);
1375 * Initialize defaults for new and unusual fields, so that file
1376 * systems which don't support these fields don't need to know
1379 vap->va_birthtime.tv_sec = -1;
1380 vap->va_birthtime.tv_nsec = 0;
1381 vap->va_fsid = VNOVAL;
1382 vap->va_rdev = NODEV;
1384 error = VOP_GETATTR(vp, vap, active_cred);
1389 * Zero the spare stat fields
1391 bzero(sb, sizeof *sb);
1394 * Copy from vattr table
1396 if (vap->va_fsid != VNOVAL)
1397 sb->st_dev = vap->va_fsid;
1399 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0];
1400 sb->st_ino = vap->va_fileid;
1401 mode = vap->va_mode;
1402 switch (vap->va_type) {
1428 sb->st_nlink = vap->va_nlink;
1429 sb->st_uid = vap->va_uid;
1430 sb->st_gid = vap->va_gid;
1431 sb->st_rdev = vap->va_rdev;
1432 if (vap->va_size > OFF_MAX)
1434 sb->st_size = vap->va_size;
1435 sb->st_atim = vap->va_atime;
1436 sb->st_mtim = vap->va_mtime;
1437 sb->st_ctim = vap->va_ctime;
1438 sb->st_birthtim = vap->va_birthtime;
1441 * According to www.opengroup.org, the meaning of st_blksize is
1442 * "a filesystem-specific preferred I/O block size for this
1443 * object. In some filesystem types, this may vary from file
1445 * Use miminum/default of PAGE_SIZE (e.g. for VCHR).
1448 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize);
1450 sb->st_flags = vap->va_flags;
1451 if (priv_check(td, PRIV_VFS_GENERATION))
1454 sb->st_gen = vap->va_gen;
1456 sb->st_blocks = vap->va_bytes / S_BLKSIZE;
1461 * File table vnode ioctl routine.
1464 vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
1472 switch (vp->v_type) {
1477 vn_lock(vp, LK_SHARED | LK_RETRY);
1478 error = VOP_GETATTR(vp, &vattr, active_cred);
1481 *(int *)data = vattr.va_size - fp->f_offset;
1487 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1492 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1500 * File table vnode poll routine.
1503 vn_poll(struct file *fp, int events, struct ucred *active_cred,
1511 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1512 AUDIT_ARG_VNODE1(vp);
1513 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp);
1518 error = VOP_POLL(vp, events, fp->f_cred, td);
1523 * Acquire the requested lock and then check for validity. LK_RETRY
1524 * permits vn_lock to return doomed vnodes.
1527 _vn_lock(struct vnode *vp, int flags, char *file, int line)
1531 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
1532 ("vn_lock: no locktype"));
1533 VNASSERT(vp->v_holdcnt != 0, vp, ("vn_lock: zero hold count"));
1535 error = VOP_LOCK1(vp, flags, file, line);
1536 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */
1537 KASSERT((flags & LK_RETRY) == 0 || error == 0,
1538 ("vn_lock: error %d incompatible with flags %#x", error, flags));
1540 if ((flags & LK_RETRY) == 0) {
1541 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0) {
1545 } else if (error != 0)
1551 * File table vnode close routine.
1554 vn_closefile(struct file *fp, struct thread *td)
1562 fp->f_ops = &badfileops;
1563 ref= (fp->f_flag & FHASLOCK) != 0 && fp->f_type == DTYPE_VNODE;
1565 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref);
1567 if (__predict_false(ref)) {
1568 lf.l_whence = SEEK_SET;
1571 lf.l_type = F_UNLCK;
1572 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK);
1579 vn_suspendable(struct mount *mp)
1582 return (mp->mnt_op->vfs_susp_clean != NULL);
1586 * Preparing to start a filesystem write operation. If the operation is
1587 * permitted, then we bump the count of operations in progress and
1588 * proceed. If a suspend request is in progress, we wait until the
1589 * suspension is over, and then proceed.
1592 vn_start_write_locked(struct mount *mp, int flags)
1596 mtx_assert(MNT_MTX(mp), MA_OWNED);
1600 * Check on status of suspension.
1602 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 ||
1603 mp->mnt_susp_owner != curthread) {
1604 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ?
1605 (flags & PCATCH) : 0) | (PUSER - 1);
1606 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1607 if (flags & V_NOWAIT) {
1608 error = EWOULDBLOCK;
1611 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags,
1617 if (flags & V_XSLEEP)
1619 mp->mnt_writeopcount++;
1621 if (error != 0 || (flags & V_XSLEEP) != 0)
1628 vn_start_write(struct vnode *vp, struct mount **mpp, int flags)
1633 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1634 ("V_MNTREF requires mp"));
1638 * If a vnode is provided, get and return the mount point that
1639 * to which it will write.
1642 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1644 if (error != EOPNOTSUPP)
1649 if ((mp = *mpp) == NULL)
1652 if (!vn_suspendable(mp)) {
1653 if (vp != NULL || (flags & V_MNTREF) != 0)
1659 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1661 * As long as a vnode is not provided we need to acquire a
1662 * refcount for the provided mountpoint too, in order to
1663 * emulate a vfs_ref().
1666 if (vp == NULL && (flags & V_MNTREF) == 0)
1669 return (vn_start_write_locked(mp, flags));
1673 * Secondary suspension. Used by operations such as vop_inactive
1674 * routines that are needed by the higher level functions. These
1675 * are allowed to proceed until all the higher level functions have
1676 * completed (indicated by mnt_writeopcount dropping to zero). At that
1677 * time, these operations are halted until the suspension is over.
1680 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags)
1685 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1686 ("V_MNTREF requires mp"));
1690 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1692 if (error != EOPNOTSUPP)
1698 * If we are not suspended or have not yet reached suspended
1699 * mode, then let the operation proceed.
1701 if ((mp = *mpp) == NULL)
1704 if (!vn_suspendable(mp)) {
1705 if (vp != NULL || (flags & V_MNTREF) != 0)
1711 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1713 * As long as a vnode is not provided we need to acquire a
1714 * refcount for the provided mountpoint too, in order to
1715 * emulate a vfs_ref().
1718 if (vp == NULL && (flags & V_MNTREF) == 0)
1720 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) {
1721 mp->mnt_secondary_writes++;
1722 mp->mnt_secondary_accwrites++;
1726 if (flags & V_NOWAIT) {
1729 return (EWOULDBLOCK);
1732 * Wait for the suspension to finish.
1734 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP |
1735 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0),
1744 * Filesystem write operation has completed. If we are suspending and this
1745 * operation is the last one, notify the suspender that the suspension is
1749 vn_finished_write(struct mount *mp)
1751 if (mp == NULL || !vn_suspendable(mp))
1755 mp->mnt_writeopcount--;
1756 if (mp->mnt_writeopcount < 0)
1757 panic("vn_finished_write: neg cnt");
1758 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
1759 mp->mnt_writeopcount <= 0)
1760 wakeup(&mp->mnt_writeopcount);
1766 * Filesystem secondary write operation has completed. If we are
1767 * suspending and this operation is the last one, notify the suspender
1768 * that the suspension is now in effect.
1771 vn_finished_secondary_write(struct mount *mp)
1773 if (mp == NULL || !vn_suspendable(mp))
1777 mp->mnt_secondary_writes--;
1778 if (mp->mnt_secondary_writes < 0)
1779 panic("vn_finished_secondary_write: neg cnt");
1780 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
1781 mp->mnt_secondary_writes <= 0)
1782 wakeup(&mp->mnt_secondary_writes);
1789 * Request a filesystem to suspend write operations.
1792 vfs_write_suspend(struct mount *mp, int flags)
1796 MPASS(vn_suspendable(mp));
1799 if (mp->mnt_susp_owner == curthread) {
1803 while (mp->mnt_kern_flag & MNTK_SUSPEND)
1804 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0);
1807 * Unmount holds a write reference on the mount point. If we
1808 * own busy reference and drain for writers, we deadlock with
1809 * the reference draining in the unmount path. Callers of
1810 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if
1811 * vfs_busy() reference is owned and caller is not in the
1814 if ((flags & VS_SKIP_UNMOUNT) != 0 &&
1815 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) {
1820 mp->mnt_kern_flag |= MNTK_SUSPEND;
1821 mp->mnt_susp_owner = curthread;
1822 if (mp->mnt_writeopcount > 0)
1823 (void) msleep(&mp->mnt_writeopcount,
1824 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0);
1827 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0)
1828 vfs_write_resume(mp, 0);
1833 * Request a filesystem to resume write operations.
1836 vfs_write_resume(struct mount *mp, int flags)
1839 MPASS(vn_suspendable(mp));
1842 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1843 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner"));
1844 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 |
1846 mp->mnt_susp_owner = NULL;
1847 wakeup(&mp->mnt_writeopcount);
1848 wakeup(&mp->mnt_flag);
1849 curthread->td_pflags &= ~TDP_IGNSUSP;
1850 if ((flags & VR_START_WRITE) != 0) {
1852 mp->mnt_writeopcount++;
1855 if ((flags & VR_NO_SUSPCLR) == 0)
1857 } else if ((flags & VR_START_WRITE) != 0) {
1859 vn_start_write_locked(mp, 0);
1866 * Helper loop around vfs_write_suspend() for filesystem unmount VFS
1870 vfs_write_suspend_umnt(struct mount *mp)
1874 MPASS(vn_suspendable(mp));
1875 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0,
1876 ("vfs_write_suspend_umnt: recursed"));
1878 /* dounmount() already called vn_start_write(). */
1880 vn_finished_write(mp);
1881 error = vfs_write_suspend(mp, 0);
1883 vn_start_write(NULL, &mp, V_WAIT);
1887 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0)
1890 vn_start_write(NULL, &mp, V_WAIT);
1892 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2);
1893 wakeup(&mp->mnt_flag);
1895 curthread->td_pflags |= TDP_IGNSUSP;
1900 * Implement kqueues for files by translating it to vnode operation.
1903 vn_kqfilter(struct file *fp, struct knote *kn)
1906 return (VOP_KQFILTER(fp->f_vnode, kn));
1910 * Simplified in-kernel wrapper calls for extended attribute access.
1911 * Both calls pass in a NULL credential, authorizing as "kernel" access.
1912 * Set IO_NODELOCKED in ioflg if the vnode is already locked.
1915 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace,
1916 const char *attrname, int *buflen, char *buf, struct thread *td)
1922 iov.iov_len = *buflen;
1925 auio.uio_iov = &iov;
1926 auio.uio_iovcnt = 1;
1927 auio.uio_rw = UIO_READ;
1928 auio.uio_segflg = UIO_SYSSPACE;
1930 auio.uio_offset = 0;
1931 auio.uio_resid = *buflen;
1933 if ((ioflg & IO_NODELOCKED) == 0)
1934 vn_lock(vp, LK_SHARED | LK_RETRY);
1936 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
1938 /* authorize attribute retrieval as kernel */
1939 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL,
1942 if ((ioflg & IO_NODELOCKED) == 0)
1946 *buflen = *buflen - auio.uio_resid;
1953 * XXX failure mode if partially written?
1956 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace,
1957 const char *attrname, int buflen, char *buf, struct thread *td)
1964 iov.iov_len = buflen;
1967 auio.uio_iov = &iov;
1968 auio.uio_iovcnt = 1;
1969 auio.uio_rw = UIO_WRITE;
1970 auio.uio_segflg = UIO_SYSSPACE;
1972 auio.uio_offset = 0;
1973 auio.uio_resid = buflen;
1975 if ((ioflg & IO_NODELOCKED) == 0) {
1976 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
1978 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1981 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
1983 /* authorize attribute setting as kernel */
1984 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td);
1986 if ((ioflg & IO_NODELOCKED) == 0) {
1987 vn_finished_write(mp);
1995 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace,
1996 const char *attrname, struct thread *td)
2001 if ((ioflg & IO_NODELOCKED) == 0) {
2002 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2004 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2007 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2009 /* authorize attribute removal as kernel */
2010 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td);
2011 if (error == EOPNOTSUPP)
2012 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL,
2015 if ((ioflg & IO_NODELOCKED) == 0) {
2016 vn_finished_write(mp);
2024 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags,
2028 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp));
2032 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp)
2035 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino,
2040 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg,
2041 int lkflags, struct vnode **rvp)
2046 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get");
2048 ltype = VOP_ISLOCKED(vp);
2049 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED,
2050 ("vn_vget_ino: vp not locked"));
2051 error = vfs_busy(mp, MBF_NOWAIT);
2055 error = vfs_busy(mp, 0);
2056 vn_lock(vp, ltype | LK_RETRY);
2060 if (vp->v_iflag & VI_DOOMED) {
2066 error = alloc(mp, alloc_arg, lkflags, rvp);
2069 vn_lock(vp, ltype | LK_RETRY);
2070 if (vp->v_iflag & VI_DOOMED) {
2083 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio,
2087 if (vp->v_type != VREG || td == NULL)
2089 if ((uoff_t)uio->uio_offset + uio->uio_resid >
2090 lim_cur(td, RLIMIT_FSIZE)) {
2091 PROC_LOCK(td->td_proc);
2092 kern_psignal(td->td_proc, SIGXFSZ);
2093 PROC_UNLOCK(td->td_proc);
2100 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
2107 vn_lock(vp, LK_SHARED | LK_RETRY);
2108 AUDIT_ARG_VNODE1(vp);
2111 return (setfmode(td, active_cred, vp, mode));
2115 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
2122 vn_lock(vp, LK_SHARED | LK_RETRY);
2123 AUDIT_ARG_VNODE1(vp);
2126 return (setfown(td, active_cred, vp, uid, gid));
2130 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end)
2134 if ((object = vp->v_object) == NULL)
2136 VM_OBJECT_WLOCK(object);
2137 vm_object_page_remove(object, start, end, 0);
2138 VM_OBJECT_WUNLOCK(object);
2142 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred)
2150 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
2151 ("Wrong command %lu", cmd));
2153 if (vn_lock(vp, LK_SHARED) != 0)
2155 if (vp->v_type != VREG) {
2159 error = VOP_GETATTR(vp, &va, cred);
2163 if (noff >= va.va_size) {
2167 bsize = vp->v_mount->mnt_stat.f_iosize;
2168 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize -
2170 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL);
2171 if (error == EOPNOTSUPP) {
2175 if ((bnp == -1 && cmd == FIOSEEKHOLE) ||
2176 (bnp != -1 && cmd == FIOSEEKDATA)) {
2183 if (noff > va.va_size)
2185 /* noff == va.va_size. There is an implicit hole at the end of file. */
2186 if (cmd == FIOSEEKDATA)
2196 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td)
2201 off_t foffset, size;
2204 cred = td->td_ucred;
2206 foffset = foffset_lock(fp, 0);
2207 noneg = (vp->v_type != VCHR);
2213 (offset > 0 && foffset > OFF_MAX - offset))) {
2220 vn_lock(vp, LK_SHARED | LK_RETRY);
2221 error = VOP_GETATTR(vp, &vattr, cred);
2227 * If the file references a disk device, then fetch
2228 * the media size and use that to determine the ending
2231 if (vattr.va_size == 0 && vp->v_type == VCHR &&
2232 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0)
2233 vattr.va_size = size;
2235 (vattr.va_size > OFF_MAX ||
2236 (offset > 0 && vattr.va_size > OFF_MAX - offset))) {
2240 offset += vattr.va_size;
2245 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td);
2248 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td);
2253 if (error == 0 && noneg && offset < 0)
2257 VFS_KNOTE_UNLOCKED(vp, 0);
2258 td->td_uretoff.tdu_off = offset;
2260 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0);
2265 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred,
2271 * Grant permission if the caller is the owner of the file, or
2272 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on
2273 * on the file. If the time pointer is null, then write
2274 * permission on the file is also sufficient.
2276 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes:
2277 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES
2278 * will be allowed to set the times [..] to the current
2281 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td);
2282 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0)
2283 error = VOP_ACCESS(vp, VWRITE, cred, td);
2288 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
2293 if (fp->f_type == DTYPE_FIFO)
2294 kif->kf_type = KF_TYPE_FIFO;
2296 kif->kf_type = KF_TYPE_VNODE;
2299 FILEDESC_SUNLOCK(fdp);
2300 error = vn_fill_kinfo_vnode(vp, kif);
2302 FILEDESC_SLOCK(fdp);
2307 vn_fill_junk(struct kinfo_file *kif)
2312 * Simulate vn_fullpath returning changing values for a given
2313 * vp during e.g. coredump.
2315 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1;
2316 olen = strlen(kif->kf_path);
2318 strcpy(&kif->kf_path[len - 1], "$");
2320 for (; olen < len; olen++)
2321 strcpy(&kif->kf_path[olen], "A");
2325 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif)
2328 char *fullpath, *freepath;
2331 kif->kf_un.kf_file.kf_file_type = vntype_to_kinfo(vp->v_type);
2334 error = vn_fullpath(curthread, vp, &fullpath, &freepath);
2336 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
2338 if (freepath != NULL)
2339 free(freepath, M_TEMP);
2341 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path,
2346 * Retrieve vnode attributes.
2348 va.va_fsid = VNOVAL;
2350 vn_lock(vp, LK_SHARED | LK_RETRY);
2351 error = VOP_GETATTR(vp, &va, curthread->td_ucred);
2355 if (va.va_fsid != VNOVAL)
2356 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid;
2358 kif->kf_un.kf_file.kf_file_fsid =
2359 vp->v_mount->mnt_stat.f_fsid.val[0];
2360 kif->kf_un.kf_file.kf_file_fsid_freebsd11 =
2361 kif->kf_un.kf_file.kf_file_fsid; /* truncate */
2362 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid;
2363 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode);
2364 kif->kf_un.kf_file.kf_file_size = va.va_size;
2365 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev;
2366 kif->kf_un.kf_file.kf_file_rdev_freebsd11 =
2367 kif->kf_un.kf_file.kf_file_rdev; /* truncate */
2372 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
2373 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
2377 struct pmckern_map_in pkm;
2383 boolean_t writecounted;
2386 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
2387 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
2389 * POSIX shared-memory objects are defined to have
2390 * kernel persistence, and are not defined to support
2391 * read(2)/write(2) -- or even open(2). Thus, we can
2392 * use MAP_ASYNC to trade on-disk coherence for speed.
2393 * The shm_open(3) library routine turns on the FPOSIXSHM
2394 * flag to request this behavior.
2396 if ((fp->f_flag & FPOSIXSHM) != 0)
2397 flags |= MAP_NOSYNC;
2402 * Ensure that file and memory protections are
2403 * compatible. Note that we only worry about
2404 * writability if mapping is shared; in this case,
2405 * current and max prot are dictated by the open file.
2406 * XXX use the vnode instead? Problem is: what
2407 * credentials do we use for determination? What if
2408 * proc does a setuid?
2411 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) {
2412 maxprot = VM_PROT_NONE;
2413 if ((prot & VM_PROT_EXECUTE) != 0)
2416 maxprot = VM_PROT_EXECUTE;
2417 if ((fp->f_flag & FREAD) != 0)
2418 maxprot |= VM_PROT_READ;
2419 else if ((prot & VM_PROT_READ) != 0)
2423 * If we are sharing potential changes via MAP_SHARED and we
2424 * are trying to get write permission although we opened it
2425 * without asking for it, bail out.
2427 if ((flags & MAP_SHARED) != 0) {
2428 if ((fp->f_flag & FWRITE) != 0)
2429 maxprot |= VM_PROT_WRITE;
2430 else if ((prot & VM_PROT_WRITE) != 0)
2433 maxprot |= VM_PROT_WRITE;
2434 cap_maxprot |= VM_PROT_WRITE;
2436 maxprot &= cap_maxprot;
2439 * For regular files and shared memory, POSIX requires that
2440 * the value of foff be a legitimate offset within the data
2441 * object. In particular, negative offsets are invalid.
2442 * Blocking negative offsets and overflows here avoids
2443 * possible wraparound or user-level access into reserved
2444 * ranges of the data object later. In contrast, POSIX does
2445 * not dictate how offsets are used by device drivers, so in
2446 * the case of a device mapping a negative offset is passed
2453 foff < 0 || foff > OFF_MAX - size)
2456 writecounted = FALSE;
2457 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp,
2458 &foff, &object, &writecounted);
2461 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
2462 foff, writecounted, td);
2465 * If this mapping was accounted for in the vnode's
2466 * writecount, then undo that now.
2469 vnode_pager_release_writecount(object, 0, size);
2470 vm_object_deallocate(object);
2473 /* Inform hwpmc(4) if an executable is being mapped. */
2474 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) {
2475 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) {
2477 pkm.pm_address = (uintptr_t) *addr;
2478 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_MMAP, (void *) &pkm);
2486 vn_fsid(struct vnode *vp, struct vattr *va)
2490 f = &vp->v_mount->mnt_stat.f_fsid;
2491 va->va_fsid = (uint32_t)f->val[1];
2492 va->va_fsid <<= sizeof(f->val[1]) * NBBY;
2493 va->va_fsid += (uint32_t)f->val[0];
2497 vn_fsync_buf(struct vnode *vp, int waitfor)
2499 struct buf *bp, *nbp;
2502 int error, maxretry;
2505 maxretry = 10000; /* large, arbitrarily chosen */
2507 if (vp->v_type == VCHR) {
2509 mp = vp->v_rdev->si_mountpt;
2516 * MARK/SCAN initialization to avoid infinite loops.
2518 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) {
2519 bp->b_vflags &= ~BV_SCANNED;
2524 * Flush all dirty buffers associated with a vnode.
2527 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
2528 if ((bp->b_vflags & BV_SCANNED) != 0)
2530 bp->b_vflags |= BV_SCANNED;
2531 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) {
2532 if (waitfor != MNT_WAIT)
2535 LK_EXCLUSIVE | LK_INTERLOCK | LK_SLEEPFAIL,
2536 BO_LOCKPTR(bo)) != 0) {
2543 KASSERT(bp->b_bufobj == bo,
2544 ("bp %p wrong b_bufobj %p should be %p",
2545 bp, bp->b_bufobj, bo));
2546 if ((bp->b_flags & B_DELWRI) == 0)
2547 panic("fsync: not dirty");
2548 if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) {
2554 if (maxretry < 1000)
2555 pause("dirty", hz < 1000 ? 1 : hz / 1000);
2561 * If synchronous the caller expects us to completely resolve all
2562 * dirty buffers in the system. Wait for in-progress I/O to
2563 * complete (which could include background bitmap writes), then
2564 * retry if dirty blocks still exist.
2566 if (waitfor == MNT_WAIT) {
2567 bufobj_wwait(bo, 0, 0);
2568 if (bo->bo_dirty.bv_cnt > 0) {
2570 * If we are unable to write any of these buffers
2571 * then we fail now rather than trying endlessly
2572 * to write them out.
2574 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs)
2575 if ((error = bp->b_error) != 0)
2577 if ((mp != NULL && mp->mnt_secondary_writes > 0) ||
2578 (error == 0 && --maxretry >= 0))
2586 vn_printf(vp, "fsync: giving up on dirty (error = %d) ", error);