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>
61 #include <sys/limits.h>
64 #include <sys/mount.h>
65 #include <sys/mutex.h>
66 #include <sys/namei.h>
67 #include <sys/vnode.h>
70 #include <sys/filio.h>
71 #include <sys/resourcevar.h>
72 #include <sys/rwlock.h>
75 #include <sys/sleepqueue.h>
76 #include <sys/sysctl.h>
77 #include <sys/ttycom.h>
79 #include <sys/syslog.h>
80 #include <sys/unistd.h>
82 #include <sys/ktrace.h>
84 #include <security/audit/audit.h>
85 #include <security/mac/mac_framework.h>
88 #include <vm/vm_extern.h>
90 #include <vm/vm_map.h>
91 #include <vm/vm_object.h>
92 #include <vm/vm_page.h>
93 #include <vm/vm_pager.h>
96 #include <sys/pmckern.h>
99 static fo_rdwr_t vn_read;
100 static fo_rdwr_t vn_write;
101 static fo_rdwr_t vn_io_fault;
102 static fo_truncate_t vn_truncate;
103 static fo_ioctl_t vn_ioctl;
104 static fo_poll_t vn_poll;
105 static fo_kqfilter_t vn_kqfilter;
106 static fo_close_t vn_closefile;
107 static fo_mmap_t vn_mmap;
108 static fo_fallocate_t vn_fallocate;
110 struct fileops vnops = {
111 .fo_read = vn_io_fault,
112 .fo_write = vn_io_fault,
113 .fo_truncate = vn_truncate,
114 .fo_ioctl = vn_ioctl,
116 .fo_kqfilter = vn_kqfilter,
117 .fo_stat = vn_statfile,
118 .fo_close = vn_closefile,
119 .fo_chmod = vn_chmod,
120 .fo_chown = vn_chown,
121 .fo_sendfile = vn_sendfile,
123 .fo_fill_kinfo = vn_fill_kinfo,
125 .fo_fallocate = vn_fallocate,
126 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE
129 const u_int io_hold_cnt = 16;
130 static int vn_io_fault_enable = 1;
131 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RWTUN,
132 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance");
133 static int vn_io_fault_prefault = 0;
134 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RWTUN,
135 &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting");
136 static int vn_io_pgcache_read_enable = 1;
137 SYSCTL_INT(_debug, OID_AUTO, vn_io_pgcache_read_enable, CTLFLAG_RWTUN,
138 &vn_io_pgcache_read_enable, 0,
139 "Enable copying from page cache for reads, avoiding fs");
140 static u_long vn_io_faults_cnt;
141 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD,
142 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers");
144 static int vfs_allow_read_dir = 0;
145 SYSCTL_INT(_security_bsd, OID_AUTO, allow_read_dir, CTLFLAG_RW,
146 &vfs_allow_read_dir, 0,
147 "Enable read(2) of directory by root for filesystems that support it");
150 * Returns true if vn_io_fault mode of handling the i/o request should
154 do_vn_io_fault(struct vnode *vp, struct uio *uio)
158 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG &&
159 (mp = vp->v_mount) != NULL &&
160 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable);
164 * Structure used to pass arguments to vn_io_fault1(), to do either
165 * file- or vnode-based I/O calls.
167 struct vn_io_fault_args {
175 struct fop_args_tag {
179 struct vop_args_tag {
185 static int vn_io_fault1(struct vnode *vp, struct uio *uio,
186 struct vn_io_fault_args *args, struct thread *td);
189 vn_open(struct nameidata *ndp, int *flagp, int cmode, struct file *fp)
191 struct thread *td = ndp->ni_cnd.cn_thread;
193 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp));
197 open2nameif(int fmode, u_int vn_open_flags)
201 res = ISOPEN | LOCKLEAF;
202 if ((fmode & O_RESOLVE_BENEATH) != 0)
204 if ((fmode & O_EMPTY_PATH) != 0)
206 if ((vn_open_flags & VN_OPEN_NOAUDIT) == 0)
208 if ((vn_open_flags & VN_OPEN_NOCAPCHECK) != 0)
210 if ((vn_open_flags & VN_OPEN_WANTIOCTLCAPS) != 0)
211 res |= WANTIOCTLCAPS;
216 * Common code for vnode open operations via a name lookup.
217 * Lookup the vnode and invoke VOP_CREATE if needed.
218 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
220 * Note that this does NOT free nameidata for the successful case,
221 * due to the NDINIT being done elsewhere.
224 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags,
225 struct ucred *cred, struct file *fp)
229 struct thread *td = ndp->ni_cnd.cn_thread;
231 struct vattr *vap = &vat;
238 if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT |
239 O_EXCL | O_DIRECTORY) ||
240 (fmode & (O_CREAT | O_EMPTY_PATH)) == (O_CREAT | O_EMPTY_PATH))
242 else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) {
243 ndp->ni_cnd.cn_nameiop = CREATE;
244 ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags);
246 * Set NOCACHE to avoid flushing the cache when
247 * rolling in many files at once.
249 * Set NC_KEEPPOSENTRY to keep positive entries if they already
250 * exist despite NOCACHE.
252 ndp->ni_cnd.cn_flags |= LOCKPARENT | NOCACHE | NC_KEEPPOSENTRY;
253 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
254 ndp->ni_cnd.cn_flags |= FOLLOW;
255 if ((vn_open_flags & VN_OPEN_INVFS) == 0)
257 if ((error = namei(ndp)) != 0)
259 if (ndp->ni_vp == NULL) {
262 vap->va_mode = cmode;
264 vap->va_vaflags |= VA_EXCLUSIVE;
265 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) {
266 NDFREE(ndp, NDF_ONLY_PNBUF);
268 if ((error = vn_start_write(NULL, &mp,
269 V_XSLEEP | PCATCH)) != 0)
274 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0)
275 ndp->ni_cnd.cn_flags |= MAKEENTRY;
277 error = mac_vnode_check_create(cred, ndp->ni_dvp,
281 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
284 if (error == 0 && (fmode & O_EXCL) != 0 &&
285 (fmode & (O_EXLOCK | O_SHLOCK)) != 0) {
287 vp->v_iflag |= VI_FOPENING;
291 VOP_VPUT_PAIR(ndp->ni_dvp, error == 0 ? &vp : NULL,
293 vn_finished_write(mp);
295 NDFREE(ndp, NDF_ONLY_PNBUF);
296 if (error == ERELOOKUP) {
304 if (ndp->ni_dvp == ndp->ni_vp)
310 if (fmode & O_EXCL) {
314 if (vp->v_type == VDIR) {
321 ndp->ni_cnd.cn_nameiop = LOOKUP;
322 ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags);
323 ndp->ni_cnd.cn_flags |= (fmode & O_NOFOLLOW) != 0 ? NOFOLLOW :
325 if ((fmode & FWRITE) == 0)
326 ndp->ni_cnd.cn_flags |= LOCKSHARED;
327 if ((error = namei(ndp)) != 0)
331 error = vn_open_vnode(vp, fmode, cred, td, fp);
334 vp->v_iflag &= ~VI_FOPENING;
343 NDFREE(ndp, NDF_ONLY_PNBUF);
351 vn_open_vnode_advlock(struct vnode *vp, int fmode, struct file *fp)
354 int error, lock_flags, type;
356 ASSERT_VOP_LOCKED(vp, "vn_open_vnode_advlock");
357 if ((fmode & (O_EXLOCK | O_SHLOCK)) == 0)
359 KASSERT(fp != NULL, ("open with flock requires fp"));
360 if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE)
363 lock_flags = VOP_ISLOCKED(vp);
366 lf.l_whence = SEEK_SET;
369 lf.l_type = (fmode & O_EXLOCK) != 0 ? F_WRLCK : F_RDLCK;
371 if ((fmode & FNONBLOCK) == 0)
373 if ((fmode & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
375 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type);
377 fp->f_flag |= FHASLOCK;
379 vn_lock(vp, lock_flags | LK_RETRY);
384 * Common code for vnode open operations once a vnode is located.
385 * Check permissions, and call the VOP_OPEN routine.
388 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred,
389 struct thread *td, struct file *fp)
394 if (vp->v_type == VLNK) {
395 if ((fmode & O_PATH) == 0 || (fmode & FEXEC) != 0)
398 if (vp->v_type != VDIR && fmode & O_DIRECTORY)
402 if ((fmode & O_PATH) == 0) {
403 if (vp->v_type == VSOCK)
405 if ((fmode & (FWRITE | O_TRUNC)) != 0) {
406 if (vp->v_type == VDIR)
410 if ((fmode & FREAD) != 0)
412 if ((fmode & O_APPEND) && (fmode & FWRITE))
415 if ((fmode & O_CREAT) != 0)
419 if ((fmode & FEXEC) != 0)
422 if ((fmode & O_VERIFY) != 0)
424 error = mac_vnode_check_open(cred, vp, accmode);
428 accmode &= ~(VCREAT | VVERIFY);
430 if ((fmode & O_CREAT) == 0 && accmode != 0) {
431 error = VOP_ACCESS(vp, accmode, cred, td);
435 if ((fmode & O_PATH) != 0) {
436 if (vp->v_type != VFIFO && vp->v_type != VSOCK &&
437 VOP_ACCESS(vp, VREAD, cred, td) == 0)
438 fp->f_flag |= FKQALLOWED;
442 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
443 vn_lock(vp, LK_UPGRADE | LK_RETRY);
444 error = VOP_OPEN(vp, fmode, cred, td, fp);
448 error = vn_open_vnode_advlock(vp, fmode, fp);
449 if (error == 0 && (fmode & FWRITE) != 0) {
450 error = VOP_ADD_WRITECOUNT(vp, 1);
452 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
453 __func__, vp, vp->v_writecount);
458 * Error from advlock or VOP_ADD_WRITECOUNT() still requires
459 * calling VOP_CLOSE() to pair with earlier VOP_OPEN().
464 * Arrange the call by having fdrop() to use
465 * vn_closefile(). This is to satisfy
466 * filesystems like devfs or tmpfs, which
467 * override fo_close().
469 fp->f_flag |= FOPENFAILED;
471 if (fp->f_ops == &badfileops) {
472 fp->f_type = DTYPE_VNODE;
478 * If there is no fp, due to kernel-mode open,
479 * we can call VOP_CLOSE() now.
481 if (vp->v_type != VFIFO && (fmode & FWRITE) != 0 &&
482 !MNT_EXTENDED_SHARED(vp->v_mount) &&
483 VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
484 vn_lock(vp, LK_UPGRADE | LK_RETRY);
485 (void)VOP_CLOSE(vp, fmode & (FREAD | FWRITE | FEXEC),
490 ASSERT_VOP_LOCKED(vp, "vn_open_vnode");
496 * Check for write permissions on the specified vnode.
497 * Prototype text segments cannot be written.
501 vn_writechk(struct vnode *vp)
504 ASSERT_VOP_LOCKED(vp, "vn_writechk");
506 * If there's shared text associated with
507 * the vnode, try to free it up once. If
508 * we fail, we can't allow writing.
520 vn_close1(struct vnode *vp, int flags, struct ucred *file_cred,
521 struct thread *td, bool keep_ref)
524 int error, lock_flags;
526 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 &&
527 MNT_EXTENDED_SHARED(vp->v_mount))
528 lock_flags = LK_SHARED;
530 lock_flags = LK_EXCLUSIVE;
532 vn_start_write(vp, &mp, V_WAIT);
533 vn_lock(vp, lock_flags | LK_RETRY);
534 AUDIT_ARG_VNODE1(vp);
535 if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) {
536 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
537 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
538 __func__, vp, vp->v_writecount);
540 error = VOP_CLOSE(vp, flags, file_cred, td);
545 vn_finished_write(mp);
550 vn_close(struct vnode *vp, int flags, struct ucred *file_cred,
554 return (vn_close1(vp, flags, file_cred, td, false));
558 * Heuristic to detect sequential operation.
561 sequential_heuristic(struct uio *uio, struct file *fp)
565 ASSERT_VOP_LOCKED(fp->f_vnode, __func__);
568 if (fp->f_flag & FRDAHEAD)
569 return (fp->f_seqcount[rw] << IO_SEQSHIFT);
572 * Offset 0 is handled specially. open() sets f_seqcount to 1 so
573 * that the first I/O is normally considered to be slightly
574 * sequential. Seeking to offset 0 doesn't change sequentiality
575 * unless previous seeks have reduced f_seqcount to 0, in which
576 * case offset 0 is not special.
578 if ((uio->uio_offset == 0 && fp->f_seqcount[rw] > 0) ||
579 uio->uio_offset == fp->f_nextoff[rw]) {
581 * f_seqcount is in units of fixed-size blocks so that it
582 * depends mainly on the amount of sequential I/O and not
583 * much on the number of sequential I/O's. The fixed size
584 * of 16384 is hard-coded here since it is (not quite) just
585 * a magic size that works well here. This size is more
586 * closely related to the best I/O size for real disks than
587 * to any block size used by software.
589 if (uio->uio_resid >= IO_SEQMAX * 16384)
590 fp->f_seqcount[rw] = IO_SEQMAX;
592 fp->f_seqcount[rw] += howmany(uio->uio_resid, 16384);
593 if (fp->f_seqcount[rw] > IO_SEQMAX)
594 fp->f_seqcount[rw] = IO_SEQMAX;
596 return (fp->f_seqcount[rw] << IO_SEQSHIFT);
599 /* Not sequential. Quickly draw-down sequentiality. */
600 if (fp->f_seqcount[rw] > 1)
601 fp->f_seqcount[rw] = 1;
603 fp->f_seqcount[rw] = 0;
608 * Package up an I/O request on a vnode into a uio and do it.
611 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset,
612 enum uio_seg segflg, int ioflg, struct ucred *active_cred,
613 struct ucred *file_cred, ssize_t *aresid, struct thread *td)
620 struct vn_io_fault_args args;
621 int error, lock_flags;
623 if (offset < 0 && vp->v_type != VCHR)
625 auio.uio_iov = &aiov;
627 aiov.iov_base = base;
629 auio.uio_resid = len;
630 auio.uio_offset = offset;
631 auio.uio_segflg = segflg;
636 if ((ioflg & IO_NODELOCKED) == 0) {
637 if ((ioflg & IO_RANGELOCKED) == 0) {
638 if (rw == UIO_READ) {
639 rl_cookie = vn_rangelock_rlock(vp, offset,
641 } else if ((ioflg & IO_APPEND) != 0) {
642 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
644 rl_cookie = vn_rangelock_wlock(vp, offset,
650 if (rw == UIO_WRITE) {
651 if (vp->v_type != VCHR &&
652 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH))
655 lock_flags = vn_lktype_write(mp, vp);
657 lock_flags = LK_SHARED;
658 vn_lock(vp, lock_flags | LK_RETRY);
662 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
664 if ((ioflg & IO_NOMACCHECK) == 0) {
666 error = mac_vnode_check_read(active_cred, file_cred,
669 error = mac_vnode_check_write(active_cred, file_cred,
674 if (file_cred != NULL)
678 if (do_vn_io_fault(vp, &auio)) {
679 args.kind = VN_IO_FAULT_VOP;
682 args.args.vop_args.vp = vp;
683 error = vn_io_fault1(vp, &auio, &args, td);
684 } else if (rw == UIO_READ) {
685 error = VOP_READ(vp, &auio, ioflg, cred);
686 } else /* if (rw == UIO_WRITE) */ {
687 error = VOP_WRITE(vp, &auio, ioflg, cred);
691 *aresid = auio.uio_resid;
693 if (auio.uio_resid && error == 0)
695 if ((ioflg & IO_NODELOCKED) == 0) {
698 vn_finished_write(mp);
701 if (rl_cookie != NULL)
702 vn_rangelock_unlock(vp, rl_cookie);
707 * Package up an I/O request on a vnode into a uio and do it. The I/O
708 * request is split up into smaller chunks and we try to avoid saturating
709 * the buffer cache while potentially holding a vnode locked, so we
710 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield()
711 * to give other processes a chance to lock the vnode (either other processes
712 * core'ing the same binary, or unrelated processes scanning the directory).
715 vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, void *base, size_t len,
716 off_t offset, enum uio_seg segflg, int ioflg, struct ucred *active_cred,
717 struct ucred *file_cred, size_t *aresid, struct thread *td)
726 * Force `offset' to a multiple of MAXBSIZE except possibly
727 * for the first chunk, so that filesystems only need to
728 * write full blocks except possibly for the first and last
731 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE;
735 if (rw != UIO_READ && vp->v_type == VREG)
738 error = vn_rdwr(rw, vp, base, chunk, offset, segflg,
739 ioflg, active_cred, file_cred, &iaresid, td);
740 len -= chunk; /* aresid calc already includes length */
744 base = (char *)base + chunk;
745 kern_yield(PRI_USER);
748 *aresid = len + iaresid;
752 #if OFF_MAX <= LONG_MAX
754 foffset_lock(struct file *fp, int flags)
756 volatile short *flagsp;
760 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
762 if ((flags & FOF_NOLOCK) != 0)
763 return (atomic_load_long(&fp->f_offset));
766 * According to McKusick the vn lock was protecting f_offset here.
767 * It is now protected by the FOFFSET_LOCKED flag.
769 flagsp = &fp->f_vnread_flags;
770 if (atomic_cmpset_acq_16(flagsp, 0, FOFFSET_LOCKED))
771 return (atomic_load_long(&fp->f_offset));
773 sleepq_lock(&fp->f_vnread_flags);
774 state = atomic_load_16(flagsp);
776 if ((state & FOFFSET_LOCKED) == 0) {
777 if (!atomic_fcmpset_acq_16(flagsp, &state,
782 if ((state & FOFFSET_LOCK_WAITING) == 0) {
783 if (!atomic_fcmpset_acq_16(flagsp, &state,
784 state | FOFFSET_LOCK_WAITING))
788 sleepq_add(&fp->f_vnread_flags, NULL, "vofflock", 0, 0);
789 sleepq_wait(&fp->f_vnread_flags, PUSER -1);
791 sleepq_lock(&fp->f_vnread_flags);
792 state = atomic_load_16(flagsp);
794 res = atomic_load_long(&fp->f_offset);
795 sleepq_release(&fp->f_vnread_flags);
800 foffset_unlock(struct file *fp, off_t val, int flags)
802 volatile short *flagsp;
805 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
807 if ((flags & FOF_NOUPDATE) == 0)
808 atomic_store_long(&fp->f_offset, val);
809 if ((flags & FOF_NEXTOFF_R) != 0)
810 fp->f_nextoff[UIO_READ] = val;
811 if ((flags & FOF_NEXTOFF_W) != 0)
812 fp->f_nextoff[UIO_WRITE] = val;
814 if ((flags & FOF_NOLOCK) != 0)
817 flagsp = &fp->f_vnread_flags;
818 state = atomic_load_16(flagsp);
819 if ((state & FOFFSET_LOCK_WAITING) == 0 &&
820 atomic_cmpset_rel_16(flagsp, state, 0))
823 sleepq_lock(&fp->f_vnread_flags);
824 MPASS((fp->f_vnread_flags & FOFFSET_LOCKED) != 0);
825 MPASS((fp->f_vnread_flags & FOFFSET_LOCK_WAITING) != 0);
826 fp->f_vnread_flags = 0;
827 sleepq_broadcast(&fp->f_vnread_flags, SLEEPQ_SLEEP, 0, 0);
828 sleepq_release(&fp->f_vnread_flags);
832 foffset_lock(struct file *fp, int flags)
837 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
839 mtxp = mtx_pool_find(mtxpool_sleep, fp);
841 if ((flags & FOF_NOLOCK) == 0) {
842 while (fp->f_vnread_flags & FOFFSET_LOCKED) {
843 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING;
844 msleep(&fp->f_vnread_flags, mtxp, PUSER -1,
847 fp->f_vnread_flags |= FOFFSET_LOCKED;
855 foffset_unlock(struct file *fp, off_t val, int flags)
859 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
861 mtxp = mtx_pool_find(mtxpool_sleep, fp);
863 if ((flags & FOF_NOUPDATE) == 0)
865 if ((flags & FOF_NEXTOFF_R) != 0)
866 fp->f_nextoff[UIO_READ] = val;
867 if ((flags & FOF_NEXTOFF_W) != 0)
868 fp->f_nextoff[UIO_WRITE] = val;
869 if ((flags & FOF_NOLOCK) == 0) {
870 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0,
871 ("Lost FOFFSET_LOCKED"));
872 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING)
873 wakeup(&fp->f_vnread_flags);
874 fp->f_vnread_flags = 0;
881 foffset_lock_uio(struct file *fp, struct uio *uio, int flags)
884 if ((flags & FOF_OFFSET) == 0)
885 uio->uio_offset = foffset_lock(fp, flags);
889 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags)
892 if ((flags & FOF_OFFSET) == 0)
893 foffset_unlock(fp, uio->uio_offset, flags);
897 get_advice(struct file *fp, struct uio *uio)
902 ret = POSIX_FADV_NORMAL;
903 if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG)
906 mtxp = mtx_pool_find(mtxpool_sleep, fp);
908 if (fp->f_advice != NULL &&
909 uio->uio_offset >= fp->f_advice->fa_start &&
910 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end)
911 ret = fp->f_advice->fa_advice;
917 get_write_ioflag(struct file *fp)
925 mp = atomic_load_ptr(&vp->v_mount);
927 if ((fp->f_flag & O_DIRECT) != 0)
930 if ((fp->f_flag & O_FSYNC) != 0 ||
931 (mp != NULL && (mp->mnt_flag & MNT_SYNCHRONOUS) != 0))
935 * For O_DSYNC we set both IO_SYNC and IO_DATASYNC, so that VOP_WRITE()
936 * or VOP_DEALLOCATE() implementations that don't understand IO_DATASYNC
937 * fall back to full O_SYNC behavior.
939 if ((fp->f_flag & O_DSYNC) != 0)
940 ioflag |= IO_SYNC | IO_DATASYNC;
946 vn_read_from_obj(struct vnode *vp, struct uio *uio)
949 vm_page_t ma[io_hold_cnt + 2];
954 MPASS(uio->uio_resid <= ptoa(io_hold_cnt + 2));
955 obj = atomic_load_ptr(&vp->v_object);
957 return (EJUSTRETURN);
960 * Depends on type stability of vm_objects.
962 vm_object_pip_add(obj, 1);
963 if ((obj->flags & OBJ_DEAD) != 0) {
965 * Note that object might be already reused from the
966 * vnode, and the OBJ_DEAD flag cleared. This is fine,
967 * we recheck for DOOMED vnode state after all pages
968 * are busied, and retract then.
970 * But we check for OBJ_DEAD to ensure that we do not
971 * busy pages while vm_object_terminate_pages()
972 * processes the queue.
978 resid = uio->uio_resid;
979 off = uio->uio_offset;
980 for (i = 0; resid > 0; i++) {
981 MPASS(i < io_hold_cnt + 2);
982 ma[i] = vm_page_grab_unlocked(obj, atop(off),
983 VM_ALLOC_NOCREAT | VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY |
989 * Skip invalid pages. Valid mask can be partial only
990 * at EOF, and we clip later.
992 if (vm_page_none_valid(ma[i])) {
993 vm_page_sunbusy(ma[i]);
1001 error = EJUSTRETURN;
1006 * Check VIRF_DOOMED after we busied our pages. Since
1007 * vgonel() terminates the vnode' vm_object, it cannot
1008 * process past pages busied by us.
1010 if (VN_IS_DOOMED(vp)) {
1011 error = EJUSTRETURN;
1015 resid = PAGE_SIZE - (uio->uio_offset & PAGE_MASK) + ptoa(i - 1);
1016 if (resid > uio->uio_resid)
1017 resid = uio->uio_resid;
1020 * Unlocked read of vnp_size is safe because truncation cannot
1021 * pass busied page. But we load vnp_size into a local
1022 * variable so that possible concurrent extension does not
1023 * break calculation.
1025 #if defined(__powerpc__) && !defined(__powerpc64__)
1026 vsz = obj->un_pager.vnp.vnp_size;
1028 vsz = atomic_load_64(&obj->un_pager.vnp.vnp_size);
1030 if (uio->uio_offset >= vsz) {
1031 error = EJUSTRETURN;
1034 if (uio->uio_offset + resid > vsz)
1035 resid = vsz - uio->uio_offset;
1037 error = vn_io_fault_pgmove(ma, uio->uio_offset & PAGE_MASK, resid, uio);
1040 for (j = 0; j < i; j++) {
1042 vm_page_reference(ma[j]);
1043 vm_page_sunbusy(ma[j]);
1046 vm_object_pip_wakeup(obj);
1049 return (uio->uio_resid == 0 ? 0 : EJUSTRETURN);
1053 * File table vnode read routine.
1056 vn_read(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
1064 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
1066 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
1069 if (fp->f_flag & FNONBLOCK)
1070 ioflag |= IO_NDELAY;
1071 if (fp->f_flag & O_DIRECT)
1072 ioflag |= IO_DIRECT;
1075 * Try to read from page cache. VIRF_DOOMED check is racy but
1076 * allows us to avoid unneeded work outright.
1078 if (vn_io_pgcache_read_enable && !mac_vnode_check_read_enabled() &&
1079 (vn_irflag_read(vp) & (VIRF_DOOMED | VIRF_PGREAD)) == VIRF_PGREAD) {
1080 error = VOP_READ_PGCACHE(vp, uio, ioflag, fp->f_cred);
1082 fp->f_nextoff[UIO_READ] = uio->uio_offset;
1085 if (error != EJUSTRETURN)
1089 advice = get_advice(fp, uio);
1090 vn_lock(vp, LK_SHARED | LK_RETRY);
1093 case POSIX_FADV_NORMAL:
1094 case POSIX_FADV_SEQUENTIAL:
1095 case POSIX_FADV_NOREUSE:
1096 ioflag |= sequential_heuristic(uio, fp);
1098 case POSIX_FADV_RANDOM:
1099 /* Disable read-ahead for random I/O. */
1102 orig_offset = uio->uio_offset;
1105 error = mac_vnode_check_read(active_cred, fp->f_cred, vp);
1108 error = VOP_READ(vp, uio, ioflag, fp->f_cred);
1109 fp->f_nextoff[UIO_READ] = uio->uio_offset;
1111 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
1112 orig_offset != uio->uio_offset)
1114 * Use POSIX_FADV_DONTNEED to flush pages and buffers
1115 * for the backing file after a POSIX_FADV_NOREUSE
1118 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
1119 POSIX_FADV_DONTNEED);
1124 * File table vnode write routine.
1127 vn_write(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
1135 bool need_finished_write;
1137 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
1139 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
1141 if (vp->v_type == VREG)
1144 if (vp->v_type == VREG && (fp->f_flag & O_APPEND) != 0)
1145 ioflag |= IO_APPEND;
1146 if ((fp->f_flag & FNONBLOCK) != 0)
1147 ioflag |= IO_NDELAY;
1148 ioflag |= get_write_ioflag(fp);
1151 need_finished_write = false;
1152 if (vp->v_type != VCHR) {
1153 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
1156 need_finished_write = true;
1159 advice = get_advice(fp, uio);
1161 vn_lock(vp, vn_lktype_write(mp, vp) | LK_RETRY);
1163 case POSIX_FADV_NORMAL:
1164 case POSIX_FADV_SEQUENTIAL:
1165 case POSIX_FADV_NOREUSE:
1166 ioflag |= sequential_heuristic(uio, fp);
1168 case POSIX_FADV_RANDOM:
1169 /* XXX: Is this correct? */
1172 orig_offset = uio->uio_offset;
1175 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
1178 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred);
1179 fp->f_nextoff[UIO_WRITE] = uio->uio_offset;
1181 if (need_finished_write)
1182 vn_finished_write(mp);
1183 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
1184 orig_offset != uio->uio_offset)
1186 * Use POSIX_FADV_DONTNEED to flush pages and buffers
1187 * for the backing file after a POSIX_FADV_NOREUSE
1190 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
1191 POSIX_FADV_DONTNEED);
1197 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to
1198 * prevent the following deadlock:
1200 * Assume that the thread A reads from the vnode vp1 into userspace
1201 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is
1202 * currently not resident, then system ends up with the call chain
1203 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] ->
1204 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2)
1205 * which establishes lock order vp1->vn_lock, then vp2->vn_lock.
1206 * If, at the same time, thread B reads from vnode vp2 into buffer buf2
1207 * backed by the pages of vnode vp1, and some page in buf2 is not
1208 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock.
1210 * To prevent the lock order reversal and deadlock, vn_io_fault() does
1211 * not allow page faults to happen during VOP_READ() or VOP_WRITE().
1212 * Instead, it first tries to do the whole range i/o with pagefaults
1213 * disabled. If all pages in the i/o buffer are resident and mapped,
1214 * VOP will succeed (ignoring the genuine filesystem errors).
1215 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do
1216 * i/o in chunks, with all pages in the chunk prefaulted and held
1217 * using vm_fault_quick_hold_pages().
1219 * Filesystems using this deadlock avoidance scheme should use the
1220 * array of the held pages from uio, saved in the curthread->td_ma,
1221 * instead of doing uiomove(). A helper function
1222 * vn_io_fault_uiomove() converts uiomove request into
1223 * uiomove_fromphys() over td_ma array.
1225 * Since vnode locks do not cover the whole i/o anymore, rangelocks
1226 * make the current i/o request atomic with respect to other i/os and
1231 * Decode vn_io_fault_args and perform the corresponding i/o.
1234 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio,
1240 save = vm_fault_disable_pagefaults();
1241 switch (args->kind) {
1242 case VN_IO_FAULT_FOP:
1243 error = (args->args.fop_args.doio)(args->args.fop_args.fp,
1244 uio, args->cred, args->flags, td);
1246 case VN_IO_FAULT_VOP:
1247 if (uio->uio_rw == UIO_READ) {
1248 error = VOP_READ(args->args.vop_args.vp, uio,
1249 args->flags, args->cred);
1250 } else if (uio->uio_rw == UIO_WRITE) {
1251 error = VOP_WRITE(args->args.vop_args.vp, uio,
1252 args->flags, args->cred);
1256 panic("vn_io_fault_doio: unknown kind of io %d %d",
1257 args->kind, uio->uio_rw);
1259 vm_fault_enable_pagefaults(save);
1264 vn_io_fault_touch(char *base, const struct uio *uio)
1269 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1))
1275 vn_io_fault_prefault_user(const struct uio *uio)
1278 const struct iovec *iov;
1283 KASSERT(uio->uio_segflg == UIO_USERSPACE,
1284 ("vn_io_fault_prefault userspace"));
1288 resid = uio->uio_resid;
1289 base = iov->iov_base;
1292 error = vn_io_fault_touch(base, uio);
1295 if (len < PAGE_SIZE) {
1297 error = vn_io_fault_touch(base + len - 1, uio);
1302 if (++i >= uio->uio_iovcnt)
1304 iov = uio->uio_iov + i;
1305 base = iov->iov_base;
1317 * Common code for vn_io_fault(), agnostic to the kind of i/o request.
1318 * Uses vn_io_fault_doio() to make the call to an actual i/o function.
1319 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request
1320 * into args and call vn_io_fault1() to handle faults during the user
1321 * mode buffer accesses.
1324 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args,
1327 vm_page_t ma[io_hold_cnt + 2];
1328 struct uio *uio_clone, short_uio;
1329 struct iovec short_iovec[1];
1330 vm_page_t *prev_td_ma;
1332 vm_offset_t addr, end;
1335 int error, cnt, saveheld, prev_td_ma_cnt;
1337 if (vn_io_fault_prefault) {
1338 error = vn_io_fault_prefault_user(uio);
1340 return (error); /* Or ignore ? */
1343 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ;
1346 * The UFS follows IO_UNIT directive and replays back both
1347 * uio_offset and uio_resid if an error is encountered during the
1348 * operation. But, since the iovec may be already advanced,
1349 * uio is still in an inconsistent state.
1351 * Cache a copy of the original uio, which is advanced to the redo
1352 * point using UIO_NOCOPY below.
1354 uio_clone = cloneuio(uio);
1355 resid = uio->uio_resid;
1357 short_uio.uio_segflg = UIO_USERSPACE;
1358 short_uio.uio_rw = uio->uio_rw;
1359 short_uio.uio_td = uio->uio_td;
1361 error = vn_io_fault_doio(args, uio, td);
1362 if (error != EFAULT)
1365 atomic_add_long(&vn_io_faults_cnt, 1);
1366 uio_clone->uio_segflg = UIO_NOCOPY;
1367 uiomove(NULL, resid - uio->uio_resid, uio_clone);
1368 uio_clone->uio_segflg = uio->uio_segflg;
1370 saveheld = curthread_pflags_set(TDP_UIOHELD);
1371 prev_td_ma = td->td_ma;
1372 prev_td_ma_cnt = td->td_ma_cnt;
1374 while (uio_clone->uio_resid != 0) {
1375 len = uio_clone->uio_iov->iov_len;
1377 KASSERT(uio_clone->uio_iovcnt >= 1,
1378 ("iovcnt underflow"));
1379 uio_clone->uio_iov++;
1380 uio_clone->uio_iovcnt--;
1383 if (len > ptoa(io_hold_cnt))
1384 len = ptoa(io_hold_cnt);
1385 addr = (uintptr_t)uio_clone->uio_iov->iov_base;
1386 end = round_page(addr + len);
1391 cnt = atop(end - trunc_page(addr));
1393 * A perfectly misaligned address and length could cause
1394 * both the start and the end of the chunk to use partial
1395 * page. +2 accounts for such a situation.
1397 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map,
1398 addr, len, prot, ma, io_hold_cnt + 2);
1403 short_uio.uio_iov = &short_iovec[0];
1404 short_iovec[0].iov_base = (void *)addr;
1405 short_uio.uio_iovcnt = 1;
1406 short_uio.uio_resid = short_iovec[0].iov_len = len;
1407 short_uio.uio_offset = uio_clone->uio_offset;
1409 td->td_ma_cnt = cnt;
1411 error = vn_io_fault_doio(args, &short_uio, td);
1412 vm_page_unhold_pages(ma, cnt);
1413 adv = len - short_uio.uio_resid;
1415 uio_clone->uio_iov->iov_base =
1416 (char *)uio_clone->uio_iov->iov_base + adv;
1417 uio_clone->uio_iov->iov_len -= adv;
1418 uio_clone->uio_resid -= adv;
1419 uio_clone->uio_offset += adv;
1421 uio->uio_resid -= adv;
1422 uio->uio_offset += adv;
1424 if (error != 0 || adv == 0)
1427 td->td_ma = prev_td_ma;
1428 td->td_ma_cnt = prev_td_ma_cnt;
1429 curthread_pflags_restore(saveheld);
1431 free(uio_clone, M_IOV);
1436 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred,
1437 int flags, struct thread *td)
1442 struct vn_io_fault_args args;
1445 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write;
1449 * The ability to read(2) on a directory has historically been
1450 * allowed for all users, but this can and has been the source of
1451 * at least one security issue in the past. As such, it is now hidden
1452 * away behind a sysctl for those that actually need it to use it, and
1453 * restricted to root when it's turned on to make it relatively safe to
1454 * leave on for longer sessions of need.
1456 if (vp->v_type == VDIR) {
1457 KASSERT(uio->uio_rw == UIO_READ,
1458 ("illegal write attempted on a directory"));
1459 if (!vfs_allow_read_dir)
1461 if ((error = priv_check(td, PRIV_VFS_READ_DIR)) != 0)
1465 foffset_lock_uio(fp, uio, flags);
1466 if (do_vn_io_fault(vp, uio)) {
1467 args.kind = VN_IO_FAULT_FOP;
1468 args.args.fop_args.fp = fp;
1469 args.args.fop_args.doio = doio;
1470 args.cred = active_cred;
1471 args.flags = flags | FOF_OFFSET;
1472 if (uio->uio_rw == UIO_READ) {
1473 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset,
1474 uio->uio_offset + uio->uio_resid);
1475 } else if ((fp->f_flag & O_APPEND) != 0 ||
1476 (flags & FOF_OFFSET) == 0) {
1477 /* For appenders, punt and lock the whole range. */
1478 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1480 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset,
1481 uio->uio_offset + uio->uio_resid);
1483 error = vn_io_fault1(vp, uio, &args, td);
1484 vn_rangelock_unlock(vp, rl_cookie);
1486 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td);
1488 foffset_unlock_uio(fp, uio, flags);
1493 * Helper function to perform the requested uiomove operation using
1494 * the held pages for io->uio_iov[0].iov_base buffer instead of
1495 * copyin/copyout. Access to the pages with uiomove_fromphys()
1496 * instead of iov_base prevents page faults that could occur due to
1497 * pmap_collect() invalidating the mapping created by
1498 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or
1499 * object cleanup revoking the write access from page mappings.
1501 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove()
1502 * instead of plain uiomove().
1505 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio)
1507 struct uio transp_uio;
1508 struct iovec transp_iov[1];
1514 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1515 uio->uio_segflg != UIO_USERSPACE)
1516 return (uiomove(data, xfersize, uio));
1518 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1519 transp_iov[0].iov_base = data;
1520 transp_uio.uio_iov = &transp_iov[0];
1521 transp_uio.uio_iovcnt = 1;
1522 if (xfersize > uio->uio_resid)
1523 xfersize = uio->uio_resid;
1524 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize;
1525 transp_uio.uio_offset = 0;
1526 transp_uio.uio_segflg = UIO_SYSSPACE;
1528 * Since transp_iov points to data, and td_ma page array
1529 * corresponds to original uio->uio_iov, we need to invert the
1530 * direction of the i/o operation as passed to
1531 * uiomove_fromphys().
1533 switch (uio->uio_rw) {
1535 transp_uio.uio_rw = UIO_READ;
1538 transp_uio.uio_rw = UIO_WRITE;
1541 transp_uio.uio_td = uio->uio_td;
1542 error = uiomove_fromphys(td->td_ma,
1543 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK,
1544 xfersize, &transp_uio);
1545 adv = xfersize - transp_uio.uio_resid;
1547 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) -
1548 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT);
1550 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1552 td->td_ma_cnt -= pgadv;
1553 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv;
1554 uio->uio_iov->iov_len -= adv;
1555 uio->uio_resid -= adv;
1556 uio->uio_offset += adv;
1561 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize,
1565 vm_offset_t iov_base;
1569 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1570 uio->uio_segflg != UIO_USERSPACE)
1571 return (uiomove_fromphys(ma, offset, xfersize, uio));
1573 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1574 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize;
1575 iov_base = (vm_offset_t)uio->uio_iov->iov_base;
1576 switch (uio->uio_rw) {
1578 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma,
1582 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK,
1586 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT);
1588 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1590 td->td_ma_cnt -= pgadv;
1591 uio->uio_iov->iov_base = (char *)(iov_base + cnt);
1592 uio->uio_iov->iov_len -= cnt;
1593 uio->uio_resid -= cnt;
1594 uio->uio_offset += cnt;
1599 * File table truncate routine.
1602 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred,
1614 * Lock the whole range for truncation. Otherwise split i/o
1615 * might happen partly before and partly after the truncation.
1617 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1618 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
1621 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1622 AUDIT_ARG_VNODE1(vp);
1623 if (vp->v_type == VDIR) {
1628 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
1632 error = vn_truncate_locked(vp, length, (fp->f_flag & O_FSYNC) != 0,
1636 vn_finished_write(mp);
1638 vn_rangelock_unlock(vp, rl_cookie);
1639 if (error == ERELOOKUP)
1645 * Truncate a file that is already locked.
1648 vn_truncate_locked(struct vnode *vp, off_t length, bool sync,
1654 error = VOP_ADD_WRITECOUNT(vp, 1);
1657 vattr.va_size = length;
1659 vattr.va_vaflags |= VA_SYNC;
1660 error = VOP_SETATTR(vp, &vattr, cred);
1661 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
1667 * File table vnode stat routine.
1670 vn_statfile(struct file *fp, struct stat *sb, struct ucred *active_cred,
1673 struct vnode *vp = fp->f_vnode;
1676 vn_lock(vp, LK_SHARED | LK_RETRY);
1677 error = VOP_STAT(vp, sb, active_cred, fp->f_cred, td);
1684 * File table vnode ioctl routine.
1687 vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
1692 struct fiobmap2_arg *bmarg;
1696 switch (vp->v_type) {
1701 vn_lock(vp, LK_SHARED | LK_RETRY);
1702 error = VOP_GETATTR(vp, &vattr, active_cred);
1705 *(int *)data = vattr.va_size - fp->f_offset;
1708 bmarg = (struct fiobmap2_arg *)data;
1709 vn_lock(vp, LK_SHARED | LK_RETRY);
1711 error = mac_vnode_check_read(active_cred, fp->f_cred,
1715 error = VOP_BMAP(vp, bmarg->bn, NULL,
1716 &bmarg->bn, &bmarg->runp, &bmarg->runb);
1723 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1728 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1736 * File table vnode poll routine.
1739 vn_poll(struct file *fp, int events, struct ucred *active_cred,
1746 #if defined(MAC) || defined(AUDIT)
1747 if (AUDITING_TD(td) || mac_vnode_check_poll_enabled()) {
1748 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1749 AUDIT_ARG_VNODE1(vp);
1750 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp);
1756 error = VOP_POLL(vp, events, fp->f_cred, td);
1761 * Acquire the requested lock and then check for validity. LK_RETRY
1762 * permits vn_lock to return doomed vnodes.
1764 static int __noinline
1765 _vn_lock_fallback(struct vnode *vp, int flags, const char *file, int line,
1769 KASSERT((flags & LK_RETRY) == 0 || error == 0,
1770 ("vn_lock: error %d incompatible with flags %#x", error, flags));
1773 VNASSERT(VN_IS_DOOMED(vp), vp, ("vnode not doomed"));
1775 if ((flags & LK_RETRY) == 0) {
1786 * Nothing to do if we got the lock.
1792 * Interlock was dropped by the call in _vn_lock.
1794 flags &= ~LK_INTERLOCK;
1796 error = VOP_LOCK1(vp, flags, file, line);
1797 } while (error != 0);
1802 _vn_lock(struct vnode *vp, int flags, const char *file, int line)
1806 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
1807 ("vn_lock: no locktype (%d passed)", flags));
1808 VNPASS(vp->v_holdcnt > 0, vp);
1809 error = VOP_LOCK1(vp, flags, file, line);
1810 if (__predict_false(error != 0 || VN_IS_DOOMED(vp)))
1811 return (_vn_lock_fallback(vp, flags, file, line, error));
1816 * File table vnode close routine.
1819 vn_closefile(struct file *fp, struct thread *td)
1827 fp->f_ops = &badfileops;
1828 ref = (fp->f_flag & FHASLOCK) != 0;
1830 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref);
1832 if (__predict_false(ref)) {
1833 lf.l_whence = SEEK_SET;
1836 lf.l_type = F_UNLCK;
1837 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK);
1844 * Preparing to start a filesystem write operation. If the operation is
1845 * permitted, then we bump the count of operations in progress and
1846 * proceed. If a suspend request is in progress, we wait until the
1847 * suspension is over, and then proceed.
1850 vn_start_write_refed(struct mount *mp, int flags, bool mplocked)
1852 struct mount_pcpu *mpcpu;
1855 if (__predict_true(!mplocked) && (flags & V_XSLEEP) == 0 &&
1856 vfs_op_thread_enter(mp, mpcpu)) {
1857 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0);
1858 vfs_mp_count_add_pcpu(mpcpu, writeopcount, 1);
1859 vfs_op_thread_exit(mp, mpcpu);
1864 mtx_assert(MNT_MTX(mp), MA_OWNED);
1871 * Check on status of suspension.
1873 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 ||
1874 mp->mnt_susp_owner != curthread) {
1875 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ?
1876 (flags & PCATCH) : 0) | (PUSER - 1);
1877 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1878 if (flags & V_NOWAIT) {
1879 error = EWOULDBLOCK;
1882 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags,
1888 if (flags & V_XSLEEP)
1890 mp->mnt_writeopcount++;
1892 if (error != 0 || (flags & V_XSLEEP) != 0)
1899 vn_start_write(struct vnode *vp, struct mount **mpp, int flags)
1904 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1905 ("V_MNTREF requires mp"));
1909 * If a vnode is provided, get and return the mount point that
1910 * to which it will write.
1913 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1915 if (error != EOPNOTSUPP)
1920 if ((mp = *mpp) == NULL)
1924 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1926 * As long as a vnode is not provided we need to acquire a
1927 * refcount for the provided mountpoint too, in order to
1928 * emulate a vfs_ref().
1930 if (vp == NULL && (flags & V_MNTREF) == 0)
1933 return (vn_start_write_refed(mp, flags, false));
1937 * Secondary suspension. Used by operations such as vop_inactive
1938 * routines that are needed by the higher level functions. These
1939 * are allowed to proceed until all the higher level functions have
1940 * completed (indicated by mnt_writeopcount dropping to zero). At that
1941 * time, these operations are halted until the suspension is over.
1944 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags)
1949 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1950 ("V_MNTREF requires mp"));
1954 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1956 if (error != EOPNOTSUPP)
1962 * If we are not suspended or have not yet reached suspended
1963 * mode, then let the operation proceed.
1965 if ((mp = *mpp) == NULL)
1969 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1971 * As long as a vnode is not provided we need to acquire a
1972 * refcount for the provided mountpoint too, in order to
1973 * emulate a vfs_ref().
1976 if (vp == NULL && (flags & V_MNTREF) == 0)
1978 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) {
1979 mp->mnt_secondary_writes++;
1980 mp->mnt_secondary_accwrites++;
1984 if (flags & V_NOWAIT) {
1987 return (EWOULDBLOCK);
1990 * Wait for the suspension to finish.
1992 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP |
1993 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0),
2002 * Filesystem write operation has completed. If we are suspending and this
2003 * operation is the last one, notify the suspender that the suspension is
2007 vn_finished_write(struct mount *mp)
2009 struct mount_pcpu *mpcpu;
2015 if (vfs_op_thread_enter(mp, mpcpu)) {
2016 vfs_mp_count_sub_pcpu(mpcpu, writeopcount, 1);
2017 vfs_mp_count_sub_pcpu(mpcpu, ref, 1);
2018 vfs_op_thread_exit(mp, mpcpu);
2023 vfs_assert_mount_counters(mp);
2025 c = --mp->mnt_writeopcount;
2026 if (mp->mnt_vfs_ops == 0) {
2027 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0);
2032 vfs_dump_mount_counters(mp);
2033 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && c == 0)
2034 wakeup(&mp->mnt_writeopcount);
2039 * Filesystem secondary write operation has completed. If we are
2040 * suspending and this operation is the last one, notify the suspender
2041 * that the suspension is now in effect.
2044 vn_finished_secondary_write(struct mount *mp)
2050 mp->mnt_secondary_writes--;
2051 if (mp->mnt_secondary_writes < 0)
2052 panic("vn_finished_secondary_write: neg cnt");
2053 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
2054 mp->mnt_secondary_writes <= 0)
2055 wakeup(&mp->mnt_secondary_writes);
2060 * Request a filesystem to suspend write operations.
2063 vfs_write_suspend(struct mount *mp, int flags)
2070 vfs_assert_mount_counters(mp);
2071 if (mp->mnt_susp_owner == curthread) {
2072 vfs_op_exit_locked(mp);
2076 while (mp->mnt_kern_flag & MNTK_SUSPEND)
2077 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0);
2080 * Unmount holds a write reference on the mount point. If we
2081 * own busy reference and drain for writers, we deadlock with
2082 * the reference draining in the unmount path. Callers of
2083 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if
2084 * vfs_busy() reference is owned and caller is not in the
2087 if ((flags & VS_SKIP_UNMOUNT) != 0 &&
2088 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) {
2089 vfs_op_exit_locked(mp);
2094 mp->mnt_kern_flag |= MNTK_SUSPEND;
2095 mp->mnt_susp_owner = curthread;
2096 if (mp->mnt_writeopcount > 0)
2097 (void) msleep(&mp->mnt_writeopcount,
2098 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0);
2101 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) {
2102 vfs_write_resume(mp, 0);
2103 /* vfs_write_resume does vfs_op_exit() for us */
2109 * Request a filesystem to resume write operations.
2112 vfs_write_resume(struct mount *mp, int flags)
2116 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
2117 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner"));
2118 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 |
2120 mp->mnt_susp_owner = NULL;
2121 wakeup(&mp->mnt_writeopcount);
2122 wakeup(&mp->mnt_flag);
2123 curthread->td_pflags &= ~TDP_IGNSUSP;
2124 if ((flags & VR_START_WRITE) != 0) {
2126 mp->mnt_writeopcount++;
2129 if ((flags & VR_NO_SUSPCLR) == 0)
2132 } else if ((flags & VR_START_WRITE) != 0) {
2134 vn_start_write_refed(mp, 0, true);
2141 * Helper loop around vfs_write_suspend() for filesystem unmount VFS
2145 vfs_write_suspend_umnt(struct mount *mp)
2149 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0,
2150 ("vfs_write_suspend_umnt: recursed"));
2152 /* dounmount() already called vn_start_write(). */
2154 vn_finished_write(mp);
2155 error = vfs_write_suspend(mp, 0);
2157 vn_start_write(NULL, &mp, V_WAIT);
2161 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0)
2164 vn_start_write(NULL, &mp, V_WAIT);
2166 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2);
2167 wakeup(&mp->mnt_flag);
2169 curthread->td_pflags |= TDP_IGNSUSP;
2174 * Implement kqueues for files by translating it to vnode operation.
2177 vn_kqfilter(struct file *fp, struct knote *kn)
2180 return (VOP_KQFILTER(fp->f_vnode, kn));
2184 vn_kqfilter_opath(struct file *fp, struct knote *kn)
2186 if ((fp->f_flag & FKQALLOWED) == 0)
2188 return (vn_kqfilter(fp, kn));
2192 * Simplified in-kernel wrapper calls for extended attribute access.
2193 * Both calls pass in a NULL credential, authorizing as "kernel" access.
2194 * Set IO_NODELOCKED in ioflg if the vnode is already locked.
2197 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace,
2198 const char *attrname, int *buflen, char *buf, struct thread *td)
2204 iov.iov_len = *buflen;
2207 auio.uio_iov = &iov;
2208 auio.uio_iovcnt = 1;
2209 auio.uio_rw = UIO_READ;
2210 auio.uio_segflg = UIO_SYSSPACE;
2212 auio.uio_offset = 0;
2213 auio.uio_resid = *buflen;
2215 if ((ioflg & IO_NODELOCKED) == 0)
2216 vn_lock(vp, LK_SHARED | LK_RETRY);
2218 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2220 /* authorize attribute retrieval as kernel */
2221 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL,
2224 if ((ioflg & IO_NODELOCKED) == 0)
2228 *buflen = *buflen - auio.uio_resid;
2235 * XXX failure mode if partially written?
2238 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace,
2239 const char *attrname, int buflen, char *buf, struct thread *td)
2246 iov.iov_len = buflen;
2249 auio.uio_iov = &iov;
2250 auio.uio_iovcnt = 1;
2251 auio.uio_rw = UIO_WRITE;
2252 auio.uio_segflg = UIO_SYSSPACE;
2254 auio.uio_offset = 0;
2255 auio.uio_resid = buflen;
2257 if ((ioflg & IO_NODELOCKED) == 0) {
2258 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2260 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2263 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2265 /* authorize attribute setting as kernel */
2266 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td);
2268 if ((ioflg & IO_NODELOCKED) == 0) {
2269 vn_finished_write(mp);
2277 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace,
2278 const char *attrname, struct thread *td)
2283 if ((ioflg & IO_NODELOCKED) == 0) {
2284 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2286 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2289 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2291 /* authorize attribute removal as kernel */
2292 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td);
2293 if (error == EOPNOTSUPP)
2294 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL,
2297 if ((ioflg & IO_NODELOCKED) == 0) {
2298 vn_finished_write(mp);
2306 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags,
2310 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp));
2314 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp)
2317 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino,
2322 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg,
2323 int lkflags, struct vnode **rvp)
2328 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get");
2330 ltype = VOP_ISLOCKED(vp);
2331 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED,
2332 ("vn_vget_ino: vp not locked"));
2333 error = vfs_busy(mp, MBF_NOWAIT);
2337 error = vfs_busy(mp, 0);
2338 vn_lock(vp, ltype | LK_RETRY);
2342 if (VN_IS_DOOMED(vp)) {
2348 error = alloc(mp, alloc_arg, lkflags, rvp);
2350 if (error != 0 || *rvp != vp)
2351 vn_lock(vp, ltype | LK_RETRY);
2352 if (VN_IS_DOOMED(vp)) {
2365 vn_send_sigxfsz(struct proc *p)
2368 kern_psignal(p, SIGXFSZ);
2373 vn_rlimit_trunc(u_quad_t size, struct thread *td)
2375 if (size <= lim_cur(td, RLIMIT_FSIZE))
2377 vn_send_sigxfsz(td->td_proc);
2382 vn_rlimit_fsizex1(const struct vnode *vp, struct uio *uio, off_t maxfsz,
2383 bool adj, struct thread *td)
2388 if (vp->v_type != VREG)
2392 * Handle file system maximum file size.
2394 if (maxfsz != 0 && uio->uio_offset + uio->uio_resid > maxfsz) {
2395 if (!adj || uio->uio_offset >= maxfsz)
2397 uio->uio_resid = maxfsz - uio->uio_offset;
2401 * This is kernel write (e.g. vnode_pager) or accounting
2402 * write, ignore limit.
2404 if (td == NULL || (td->td_pflags2 & TDP2_ACCT) != 0)
2408 * Calculate file size limit.
2410 ktr_write = (td->td_pflags & TDP_INKTRACE) != 0;
2411 lim = __predict_false(ktr_write) ? td->td_ktr_io_lim :
2412 lim_cur(td, RLIMIT_FSIZE);
2415 * Is the limit reached?
2417 if (__predict_true((uoff_t)uio->uio_offset + uio->uio_resid <= lim))
2421 * Prepared filesystems can handle writes truncated to the
2424 if (adj && (uoff_t)uio->uio_offset < lim) {
2425 uio->uio_resid = lim - (uoff_t)uio->uio_offset;
2429 if (!ktr_write || ktr_filesize_limit_signal)
2430 vn_send_sigxfsz(td->td_proc);
2435 * Helper for VOP_WRITE() implementations, the common code to
2436 * handle maximum supported file size on the filesystem, and
2437 * RLIMIT_FSIZE, except for special writes from accounting subsystem
2440 * For maximum file size (maxfsz argument):
2441 * - return EFBIG if uio_offset is beyond it
2442 * - otherwise, clamp uio_resid if write would extend file beyond maxfsz.
2445 * - return EFBIG and send SIGXFSZ if uio_offset is beyond the limit
2446 * - otherwise, clamp uio_resid if write would extend file beyond limit.
2448 * If clamping occured, the adjustment for uio_resid is stored in
2449 * *resid_adj, to be re-applied by vn_rlimit_fsizex_res() on return
2453 vn_rlimit_fsizex(const struct vnode *vp, struct uio *uio, off_t maxfsz,
2454 ssize_t *resid_adj, struct thread *td)
2460 resid_orig = uio->uio_resid;
2461 adj = resid_adj != NULL;
2462 error = vn_rlimit_fsizex1(vp, uio, maxfsz, adj, td);
2464 *resid_adj = resid_orig - uio->uio_resid;
2469 vn_rlimit_fsizex_res(struct uio *uio, ssize_t resid_adj)
2471 uio->uio_resid += resid_adj;
2475 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio,
2478 return (vn_rlimit_fsizex(vp, __DECONST(struct uio *, uio), 0, NULL,
2483 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
2490 vn_lock(vp, LK_SHARED | LK_RETRY);
2491 AUDIT_ARG_VNODE1(vp);
2494 return (setfmode(td, active_cred, vp, mode));
2498 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
2505 vn_lock(vp, LK_SHARED | LK_RETRY);
2506 AUDIT_ARG_VNODE1(vp);
2509 return (setfown(td, active_cred, vp, uid, gid));
2513 * Remove pages in the range ["start", "end") from the vnode's VM object. If
2514 * "end" is 0, then the range extends to the end of the object.
2517 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end)
2521 if ((object = vp->v_object) == NULL)
2523 VM_OBJECT_WLOCK(object);
2524 vm_object_page_remove(object, start, end, 0);
2525 VM_OBJECT_WUNLOCK(object);
2529 * Like vn_pages_remove(), but skips invalid pages, which by definition are not
2530 * mapped into any process' address space. Filesystems may use this in
2531 * preference to vn_pages_remove() to avoid blocking on pages busied in
2532 * preparation for a VOP_GETPAGES.
2535 vn_pages_remove_valid(struct vnode *vp, vm_pindex_t start, vm_pindex_t end)
2539 if ((object = vp->v_object) == NULL)
2541 VM_OBJECT_WLOCK(object);
2542 vm_object_page_remove(object, start, end, OBJPR_VALIDONLY);
2543 VM_OBJECT_WUNLOCK(object);
2547 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred)
2555 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
2556 ("Wrong command %lu", cmd));
2558 if (vn_lock(vp, LK_SHARED) != 0)
2560 if (vp->v_type != VREG) {
2564 error = VOP_GETATTR(vp, &va, cred);
2568 if (noff < 0 || noff >= va.va_size) {
2572 bsize = vp->v_mount->mnt_stat.f_iosize;
2573 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize -
2575 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL);
2576 if (error == EOPNOTSUPP) {
2580 if ((bnp == -1 && cmd == FIOSEEKHOLE) ||
2581 (bnp != -1 && cmd == FIOSEEKDATA)) {
2588 if (noff > va.va_size)
2590 /* noff == va.va_size. There is an implicit hole at the end of file. */
2591 if (cmd == FIOSEEKDATA)
2601 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td)
2606 off_t foffset, size;
2609 cred = td->td_ucred;
2611 foffset = foffset_lock(fp, 0);
2612 noneg = (vp->v_type != VCHR);
2618 (offset > 0 && foffset > OFF_MAX - offset))) {
2625 vn_lock(vp, LK_SHARED | LK_RETRY);
2626 error = VOP_GETATTR(vp, &vattr, cred);
2632 * If the file references a disk device, then fetch
2633 * the media size and use that to determine the ending
2636 if (vattr.va_size == 0 && vp->v_type == VCHR &&
2637 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0)
2638 vattr.va_size = size;
2640 (vattr.va_size > OFF_MAX ||
2641 (offset > 0 && vattr.va_size > OFF_MAX - offset))) {
2645 offset += vattr.va_size;
2650 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td);
2651 if (error == ENOTTY)
2655 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td);
2656 if (error == ENOTTY)
2662 if (error == 0 && noneg && offset < 0)
2666 VFS_KNOTE_UNLOCKED(vp, 0);
2667 td->td_uretoff.tdu_off = offset;
2669 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0);
2674 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred,
2680 * Grant permission if the caller is the owner of the file, or
2681 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on
2682 * on the file. If the time pointer is null, then write
2683 * permission on the file is also sufficient.
2685 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes:
2686 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES
2687 * will be allowed to set the times [..] to the current
2690 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td);
2691 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0)
2692 error = VOP_ACCESS(vp, VWRITE, cred, td);
2697 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
2702 if (fp->f_type == DTYPE_FIFO)
2703 kif->kf_type = KF_TYPE_FIFO;
2705 kif->kf_type = KF_TYPE_VNODE;
2708 FILEDESC_SUNLOCK(fdp);
2709 error = vn_fill_kinfo_vnode(vp, kif);
2711 FILEDESC_SLOCK(fdp);
2716 vn_fill_junk(struct kinfo_file *kif)
2721 * Simulate vn_fullpath returning changing values for a given
2722 * vp during e.g. coredump.
2724 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1;
2725 olen = strlen(kif->kf_path);
2727 strcpy(&kif->kf_path[len - 1], "$");
2729 for (; olen < len; olen++)
2730 strcpy(&kif->kf_path[olen], "A");
2734 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif)
2737 char *fullpath, *freepath;
2740 kif->kf_un.kf_file.kf_file_type = vntype_to_kinfo(vp->v_type);
2743 error = vn_fullpath(vp, &fullpath, &freepath);
2745 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
2747 if (freepath != NULL)
2748 free(freepath, M_TEMP);
2750 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path,
2755 * Retrieve vnode attributes.
2757 va.va_fsid = VNOVAL;
2759 vn_lock(vp, LK_SHARED | LK_RETRY);
2760 error = VOP_GETATTR(vp, &va, curthread->td_ucred);
2764 if (va.va_fsid != VNOVAL)
2765 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid;
2767 kif->kf_un.kf_file.kf_file_fsid =
2768 vp->v_mount->mnt_stat.f_fsid.val[0];
2769 kif->kf_un.kf_file.kf_file_fsid_freebsd11 =
2770 kif->kf_un.kf_file.kf_file_fsid; /* truncate */
2771 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid;
2772 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode);
2773 kif->kf_un.kf_file.kf_file_size = va.va_size;
2774 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev;
2775 kif->kf_un.kf_file.kf_file_rdev_freebsd11 =
2776 kif->kf_un.kf_file.kf_file_rdev; /* truncate */
2781 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
2782 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
2786 struct pmckern_map_in pkm;
2792 boolean_t writecounted;
2795 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
2796 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
2798 * POSIX shared-memory objects are defined to have
2799 * kernel persistence, and are not defined to support
2800 * read(2)/write(2) -- or even open(2). Thus, we can
2801 * use MAP_ASYNC to trade on-disk coherence for speed.
2802 * The shm_open(3) library routine turns on the FPOSIXSHM
2803 * flag to request this behavior.
2805 if ((fp->f_flag & FPOSIXSHM) != 0)
2806 flags |= MAP_NOSYNC;
2811 * Ensure that file and memory protections are
2812 * compatible. Note that we only worry about
2813 * writability if mapping is shared; in this case,
2814 * current and max prot are dictated by the open file.
2815 * XXX use the vnode instead? Problem is: what
2816 * credentials do we use for determination? What if
2817 * proc does a setuid?
2820 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) {
2821 maxprot = VM_PROT_NONE;
2822 if ((prot & VM_PROT_EXECUTE) != 0)
2825 maxprot = VM_PROT_EXECUTE;
2826 if ((fp->f_flag & FREAD) != 0)
2827 maxprot |= VM_PROT_READ;
2828 else if ((prot & VM_PROT_READ) != 0)
2832 * If we are sharing potential changes via MAP_SHARED and we
2833 * are trying to get write permission although we opened it
2834 * without asking for it, bail out.
2836 if ((flags & MAP_SHARED) != 0) {
2837 if ((fp->f_flag & FWRITE) != 0)
2838 maxprot |= VM_PROT_WRITE;
2839 else if ((prot & VM_PROT_WRITE) != 0)
2842 maxprot |= VM_PROT_WRITE;
2843 cap_maxprot |= VM_PROT_WRITE;
2845 maxprot &= cap_maxprot;
2848 * For regular files and shared memory, POSIX requires that
2849 * the value of foff be a legitimate offset within the data
2850 * object. In particular, negative offsets are invalid.
2851 * Blocking negative offsets and overflows here avoids
2852 * possible wraparound or user-level access into reserved
2853 * ranges of the data object later. In contrast, POSIX does
2854 * not dictate how offsets are used by device drivers, so in
2855 * the case of a device mapping a negative offset is passed
2862 foff > OFF_MAX - size)
2865 writecounted = FALSE;
2866 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp,
2867 &foff, &object, &writecounted);
2870 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
2871 foff, writecounted, td);
2874 * If this mapping was accounted for in the vnode's
2875 * writecount, then undo that now.
2878 vm_pager_release_writecount(object, 0, size);
2879 vm_object_deallocate(object);
2882 /* Inform hwpmc(4) if an executable is being mapped. */
2883 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) {
2884 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) {
2886 pkm.pm_address = (uintptr_t) *addr;
2887 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_MMAP, (void *) &pkm);
2895 vn_fsid(struct vnode *vp, struct vattr *va)
2899 f = &vp->v_mount->mnt_stat.f_fsid;
2900 va->va_fsid = (uint32_t)f->val[1];
2901 va->va_fsid <<= sizeof(f->val[1]) * NBBY;
2902 va->va_fsid += (uint32_t)f->val[0];
2906 vn_fsync_buf(struct vnode *vp, int waitfor)
2908 struct buf *bp, *nbp;
2911 int error, maxretry;
2914 maxretry = 10000; /* large, arbitrarily chosen */
2916 if (vp->v_type == VCHR) {
2918 mp = vp->v_rdev->si_mountpt;
2925 * MARK/SCAN initialization to avoid infinite loops.
2927 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) {
2928 bp->b_vflags &= ~BV_SCANNED;
2933 * Flush all dirty buffers associated with a vnode.
2936 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
2937 if ((bp->b_vflags & BV_SCANNED) != 0)
2939 bp->b_vflags |= BV_SCANNED;
2940 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) {
2941 if (waitfor != MNT_WAIT)
2944 LK_EXCLUSIVE | LK_INTERLOCK | LK_SLEEPFAIL,
2945 BO_LOCKPTR(bo)) != 0) {
2952 KASSERT(bp->b_bufobj == bo,
2953 ("bp %p wrong b_bufobj %p should be %p",
2954 bp, bp->b_bufobj, bo));
2955 if ((bp->b_flags & B_DELWRI) == 0)
2956 panic("fsync: not dirty");
2957 if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) {
2963 if (maxretry < 1000)
2964 pause("dirty", hz < 1000 ? 1 : hz / 1000);
2970 * If synchronous the caller expects us to completely resolve all
2971 * dirty buffers in the system. Wait for in-progress I/O to
2972 * complete (which could include background bitmap writes), then
2973 * retry if dirty blocks still exist.
2975 if (waitfor == MNT_WAIT) {
2976 bufobj_wwait(bo, 0, 0);
2977 if (bo->bo_dirty.bv_cnt > 0) {
2979 * If we are unable to write any of these buffers
2980 * then we fail now rather than trying endlessly
2981 * to write them out.
2983 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs)
2984 if ((error = bp->b_error) != 0)
2986 if ((mp != NULL && mp->mnt_secondary_writes > 0) ||
2987 (error == 0 && --maxretry >= 0))
2995 vn_printf(vp, "fsync: giving up on dirty (error = %d) ", error);
3001 * Copies a byte range from invp to outvp. Calls VOP_COPY_FILE_RANGE()
3002 * or vn_generic_copy_file_range() after rangelocking the byte ranges,
3003 * to do the actual copy.
3004 * vn_generic_copy_file_range() is factored out, so it can be called
3005 * from a VOP_COPY_FILE_RANGE() call as well, but handles vnodes from
3006 * different file systems.
3009 vn_copy_file_range(struct vnode *invp, off_t *inoffp, struct vnode *outvp,
3010 off_t *outoffp, size_t *lenp, unsigned int flags, struct ucred *incred,
3011 struct ucred *outcred, struct thread *fsize_td)
3018 *lenp = 0; /* For error returns. */
3021 /* Do some sanity checks on the arguments. */
3022 if (invp->v_type == VDIR || outvp->v_type == VDIR)
3024 else if (*inoffp < 0 || *outoffp < 0 ||
3025 invp->v_type != VREG || outvp->v_type != VREG)
3030 /* Ensure offset + len does not wrap around. */
3033 if (uval > INT64_MAX)
3034 len = INT64_MAX - *inoffp;
3037 if (uval > INT64_MAX)
3038 len = INT64_MAX - *outoffp;
3043 * If the two vnode are for the same file system, call
3044 * VOP_COPY_FILE_RANGE(), otherwise call vn_generic_copy_file_range()
3045 * which can handle copies across multiple file systems.
3048 if (invp->v_mount == outvp->v_mount)
3049 error = VOP_COPY_FILE_RANGE(invp, inoffp, outvp, outoffp,
3050 lenp, flags, incred, outcred, fsize_td);
3052 error = vn_generic_copy_file_range(invp, inoffp, outvp,
3053 outoffp, lenp, flags, incred, outcred, fsize_td);
3059 * Test len bytes of data starting at dat for all bytes == 0.
3060 * Return true if all bytes are zero, false otherwise.
3061 * Expects dat to be well aligned.
3064 mem_iszero(void *dat, int len)
3070 for (p = dat; len > 0; len -= sizeof(*p), p++) {
3071 if (len >= sizeof(*p)) {
3075 cp = (const char *)p;
3076 for (i = 0; i < len; i++, cp++)
3085 * Look for a hole in the output file and, if found, adjust *outoffp
3086 * and *xferp to skip past the hole.
3087 * *xferp is the entire hole length to be written and xfer2 is how many bytes
3088 * to be written as 0's upon return.
3091 vn_skip_hole(struct vnode *outvp, off_t xfer2, off_t *outoffp, off_t *xferp,
3092 off_t *dataoffp, off_t *holeoffp, struct ucred *cred)
3097 if (*holeoffp == 0 || *holeoffp <= *outoffp) {
3098 *dataoffp = *outoffp;
3099 error = VOP_IOCTL(outvp, FIOSEEKDATA, dataoffp, 0, cred,
3102 *holeoffp = *dataoffp;
3103 error = VOP_IOCTL(outvp, FIOSEEKHOLE, holeoffp, 0, cred,
3106 if (error != 0 || *holeoffp == *dataoffp) {
3108 * Since outvp is unlocked, it may be possible for
3109 * another thread to do a truncate(), lseek(), write()
3110 * creating a hole at startoff between the above
3111 * VOP_IOCTL() calls, if the other thread does not do
3113 * If that happens, *holeoffp == *dataoffp and finding
3114 * the hole has failed, so disable vn_skip_hole().
3116 *holeoffp = -1; /* Disable use of vn_skip_hole(). */
3119 KASSERT(*dataoffp >= *outoffp,
3120 ("vn_skip_hole: dataoff=%jd < outoff=%jd",
3121 (intmax_t)*dataoffp, (intmax_t)*outoffp));
3122 KASSERT(*holeoffp > *dataoffp,
3123 ("vn_skip_hole: holeoff=%jd <= dataoff=%jd",
3124 (intmax_t)*holeoffp, (intmax_t)*dataoffp));
3128 * If there is a hole before the data starts, advance *outoffp and
3129 * *xferp past the hole.
3131 if (*dataoffp > *outoffp) {
3132 delta = *dataoffp - *outoffp;
3133 if (delta >= *xferp) {
3134 /* Entire *xferp is a hole. */
3141 xfer2 = MIN(xfer2, *xferp);
3145 * If a hole starts before the end of this xfer2, reduce this xfer2 so
3146 * that the write ends at the start of the hole.
3147 * *holeoffp should always be greater than *outoffp, but for the
3148 * non-INVARIANTS case, check this to make sure xfer2 remains a sane
3151 if (*holeoffp > *outoffp && *holeoffp < *outoffp + xfer2)
3152 xfer2 = *holeoffp - *outoffp;
3157 * Write an xfer sized chunk to outvp in blksize blocks from dat.
3158 * dat is a maximum of blksize in length and can be written repeatedly in
3160 * If growfile == true, just grow the file via vn_truncate_locked() instead
3161 * of doing actual writes.
3162 * If checkhole == true, a hole is being punched, so skip over any hole
3163 * already in the output file.
3166 vn_write_outvp(struct vnode *outvp, char *dat, off_t outoff, off_t xfer,
3167 u_long blksize, bool growfile, bool checkhole, struct ucred *cred)
3170 off_t dataoff, holeoff, xfer2;
3174 * Loop around doing writes of blksize until write has been completed.
3175 * Lock/unlock on each loop iteration so that a bwillwrite() can be
3176 * done for each iteration, since the xfer argument can be very
3177 * large if there is a large hole to punch in the output file.
3182 xfer2 = MIN(xfer, blksize);
3185 * Punching a hole. Skip writing if there is
3186 * already a hole in the output file.
3188 xfer2 = vn_skip_hole(outvp, xfer2, &outoff, &xfer,
3189 &dataoff, &holeoff, cred);
3194 KASSERT(xfer2 > 0, ("vn_write_outvp: xfer2=%jd",
3199 error = vn_start_write(outvp, &mp, V_WAIT);
3203 error = vn_lock(outvp, LK_EXCLUSIVE);
3205 error = vn_truncate_locked(outvp, outoff + xfer,
3210 error = vn_lock(outvp, vn_lktype_write(mp, outvp));
3212 error = vn_rdwr(UIO_WRITE, outvp, dat, xfer2,
3213 outoff, UIO_SYSSPACE, IO_NODELOCKED,
3214 curthread->td_ucred, cred, NULL, curthread);
3221 vn_finished_write(mp);
3222 } while (!growfile && xfer > 0 && error == 0);
3227 * Copy a byte range of one file to another. This function can handle the
3228 * case where invp and outvp are on different file systems.
3229 * It can also be called by a VOP_COPY_FILE_RANGE() to do the work, if there
3230 * is no better file system specific way to do it.
3233 vn_generic_copy_file_range(struct vnode *invp, off_t *inoffp,
3234 struct vnode *outvp, off_t *outoffp, size_t *lenp, unsigned int flags,
3235 struct ucred *incred, struct ucred *outcred, struct thread *fsize_td)
3237 struct vattr va, inva;
3239 off_t startoff, endoff, xfer, xfer2;
3241 int error, interrupted;
3242 bool cantseek, readzeros, eof, lastblock, holetoeof;
3243 ssize_t aresid, r = 0;
3244 size_t copylen, len, savlen;
3246 long holein, holeout;
3247 struct timespec curts, endts;
3249 holein = holeout = 0;
3250 savlen = len = *lenp;
3255 error = vn_lock(invp, LK_SHARED);
3258 if (VOP_PATHCONF(invp, _PC_MIN_HOLE_SIZE, &holein) != 0)
3261 error = VOP_GETATTR(invp, &inva, incred);
3267 error = vn_start_write(outvp, &mp, V_WAIT);
3269 error = vn_lock(outvp, LK_EXCLUSIVE);
3272 * If fsize_td != NULL, do a vn_rlimit_fsizex() call,
3273 * now that outvp is locked.
3275 if (fsize_td != NULL) {
3278 io.uio_offset = *outoffp;
3280 error = vn_rlimit_fsizex(outvp, &io, 0, &r, fsize_td);
3281 len = savlen = io.uio_resid;
3283 * No need to call vn_rlimit_fsizex_res before return,
3284 * since the uio is local.
3287 if (VOP_PATHCONF(outvp, _PC_MIN_HOLE_SIZE, &holeout) != 0)
3290 * Holes that are past EOF do not need to be written as a block
3291 * of zero bytes. So, truncate the output file as far as
3292 * possible and then use va.va_size to decide if writing 0
3293 * bytes is necessary in the loop below.
3296 error = VOP_GETATTR(outvp, &va, outcred);
3297 if (error == 0 && va.va_size > *outoffp && va.va_size <=
3300 error = mac_vnode_check_write(curthread->td_ucred,
3304 error = vn_truncate_locked(outvp, *outoffp,
3307 va.va_size = *outoffp;
3312 vn_finished_write(mp);
3316 if (holein == 0 && holeout > 0) {
3318 * For this special case, the input data will be scanned
3319 * for blocks of all 0 bytes. For these blocks, the
3320 * write can be skipped for the output file to create
3321 * an unallocated region.
3322 * Therefore, use the appropriate size for the output file.
3325 if (blksize <= 512) {
3327 * Use f_iosize, since ZFS reports a _PC_MIN_HOLE_SIZE
3328 * of 512, although it actually only creates
3329 * unallocated regions for blocks >= f_iosize.
3331 blksize = outvp->v_mount->mnt_stat.f_iosize;
3335 * Use the larger of the two f_iosize values. If they are
3336 * not the same size, one will normally be an exact multiple of
3337 * the other, since they are both likely to be a power of 2.
3339 blksize = MAX(invp->v_mount->mnt_stat.f_iosize,
3340 outvp->v_mount->mnt_stat.f_iosize);
3343 /* Clip to sane limits. */
3346 else if (blksize > maxphys)
3348 dat = malloc(blksize, M_TEMP, M_WAITOK);
3351 * If VOP_IOCTL(FIOSEEKHOLE) works for invp, use it and FIOSEEKDATA
3352 * to find holes. Otherwise, just scan the read block for all 0s
3353 * in the inner loop where the data copying is done.
3354 * Note that some file systems such as NFSv3, NFSv4.0 and NFSv4.1 may
3355 * support holes on the server, but do not support FIOSEEKHOLE.
3356 * The kernel flag COPY_FILE_RANGE_TIMEO1SEC is used to indicate
3357 * that this function should return after 1second with a partial
3360 if ((flags & COPY_FILE_RANGE_TIMEO1SEC) != 0) {
3361 getnanouptime(&endts);
3364 timespecclear(&endts);
3365 holetoeof = eof = false;
3366 while (len > 0 && error == 0 && !eof && interrupted == 0) {
3367 endoff = 0; /* To shut up compilers. */
3373 * Find the next data area. If there is just a hole to EOF,
3374 * FIOSEEKDATA should fail with ENXIO.
3375 * (I do not know if any file system will report a hole to
3376 * EOF via FIOSEEKHOLE, but I am pretty sure FIOSEEKDATA
3377 * will fail for those file systems.)
3379 * For input files that don't support FIOSEEKDATA/FIOSEEKHOLE,
3380 * the code just falls through to the inner copy loop.
3384 error = VOP_IOCTL(invp, FIOSEEKDATA, &startoff, 0,
3386 if (error == ENXIO) {
3387 startoff = endoff = inva.va_size;
3388 eof = holetoeof = true;
3392 if (error == 0 && !holetoeof) {
3394 error = VOP_IOCTL(invp, FIOSEEKHOLE, &endoff, 0,
3397 * Since invp is unlocked, it may be possible for
3398 * another thread to do a truncate(), lseek(), write()
3399 * creating a hole at startoff between the above
3400 * VOP_IOCTL() calls, if the other thread does not do
3402 * If that happens, startoff == endoff and finding
3403 * the hole has failed, so set an error.
3405 if (error == 0 && startoff == endoff)
3406 error = EINVAL; /* Any error. Reset to 0. */
3409 if (startoff > *inoffp) {
3410 /* Found hole before data block. */
3411 xfer = MIN(startoff - *inoffp, len);
3412 if (*outoffp < va.va_size) {
3413 /* Must write 0s to punch hole. */
3414 xfer2 = MIN(va.va_size - *outoffp,
3416 memset(dat, 0, MIN(xfer2, blksize));
3417 error = vn_write_outvp(outvp, dat,
3418 *outoffp, xfer2, blksize, false,
3419 holeout > 0, outcred);
3422 if (error == 0 && *outoffp + xfer >
3423 va.va_size && (xfer == len || holetoeof)) {
3424 /* Grow output file (hole at end). */
3425 error = vn_write_outvp(outvp, dat,
3426 *outoffp, xfer, blksize, true,
3434 interrupted = sig_intr();
3435 if (timespecisset(&endts) &&
3437 getnanouptime(&curts);
3438 if (timespeccmp(&curts,
3446 copylen = MIN(len, endoff - startoff);
3458 * Set first xfer to end at a block boundary, so that
3459 * holes are more likely detected in the loop below via
3460 * the for all bytes 0 method.
3462 xfer -= (*inoffp % blksize);
3464 /* Loop copying the data block. */
3465 while (copylen > 0 && error == 0 && !eof && interrupted == 0) {
3468 error = vn_lock(invp, LK_SHARED);
3471 error = vn_rdwr(UIO_READ, invp, dat, xfer,
3472 startoff, UIO_SYSSPACE, IO_NODELOCKED,
3473 curthread->td_ucred, incred, &aresid,
3477 if (error == 0 && aresid > 0) {
3478 /* Stop the copy at EOF on the input file. */
3485 * Skip the write for holes past the initial EOF
3486 * of the output file, unless this is the last
3487 * write of the output file at EOF.
3489 readzeros = cantseek ? mem_iszero(dat, xfer) :
3493 if (!cantseek || *outoffp < va.va_size ||
3494 lastblock || !readzeros)
3495 error = vn_write_outvp(outvp, dat,
3496 *outoffp, xfer, blksize,
3497 readzeros && lastblock &&
3498 *outoffp >= va.va_size, false,
3507 interrupted = sig_intr();
3508 if (timespecisset(&endts) &&
3510 getnanouptime(&curts);
3511 if (timespeccmp(&curts,
3523 *lenp = savlen - len;
3529 vn_fallocate(struct file *fp, off_t offset, off_t len, struct thread *td)
3533 off_t olen, ooffset;
3536 int audited_vnode1 = 0;
3540 if (vp->v_type != VREG)
3543 /* Allocating blocks may take a long time, so iterate. */
3550 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
3553 error = vn_lock(vp, LK_EXCLUSIVE);
3555 vn_finished_write(mp);
3559 if (!audited_vnode1) {
3560 AUDIT_ARG_VNODE1(vp);
3565 error = mac_vnode_check_write(td->td_ucred, fp->f_cred, vp);
3568 error = VOP_ALLOCATE(vp, &offset, &len, 0,
3571 vn_finished_write(mp);
3573 if (olen + ooffset != offset + len) {
3574 panic("offset + len changed from %jx/%jx to %jx/%jx",
3575 ooffset, olen, offset, len);
3577 if (error != 0 || len == 0)
3579 KASSERT(olen > len, ("Iteration did not make progress?"));
3586 static u_long vn_lock_pair_pause_cnt;
3587 SYSCTL_ULONG(_debug, OID_AUTO, vn_lock_pair_pause, CTLFLAG_RD,
3588 &vn_lock_pair_pause_cnt, 0,
3589 "Count of vn_lock_pair deadlocks");
3591 u_int vn_lock_pair_pause_max;
3592 SYSCTL_UINT(_debug, OID_AUTO, vn_lock_pair_pause_max, CTLFLAG_RW,
3593 &vn_lock_pair_pause_max, 0,
3594 "Max ticks for vn_lock_pair deadlock avoidance sleep");
3597 vn_lock_pair_pause(const char *wmesg)
3599 atomic_add_long(&vn_lock_pair_pause_cnt, 1);
3600 pause(wmesg, prng32_bounded(vn_lock_pair_pause_max));
3604 * Lock pair of vnodes vp1, vp2, avoiding lock order reversal.
3605 * vp1_locked indicates whether vp1 is exclusively locked; if not, vp1
3606 * must be unlocked. Same for vp2 and vp2_locked. One of the vnodes
3609 * The function returns with both vnodes exclusively locked, and
3610 * guarantees that it does not create lock order reversal with other
3611 * threads during its execution. Both vnodes could be unlocked
3612 * temporary (and reclaimed).
3615 vn_lock_pair(struct vnode *vp1, bool vp1_locked, struct vnode *vp2,
3620 if (vp1 == NULL && vp2 == NULL)
3624 ASSERT_VOP_ELOCKED(vp1, "vp1");
3626 ASSERT_VOP_UNLOCKED(vp1, "vp1");
3632 ASSERT_VOP_ELOCKED(vp2, "vp2");
3634 ASSERT_VOP_UNLOCKED(vp2, "vp2");
3638 if (!vp1_locked && !vp2_locked) {
3639 vn_lock(vp1, LK_EXCLUSIVE | LK_RETRY);
3644 if (vp1_locked && vp2_locked)
3646 if (vp1_locked && vp2 != NULL) {
3648 error = VOP_LOCK1(vp2, LK_EXCLUSIVE | LK_NOWAIT,
3649 __FILE__, __LINE__);
3654 vn_lock_pair_pause("vlp1");
3656 vn_lock(vp2, LK_EXCLUSIVE | LK_RETRY);
3659 if (vp2_locked && vp1 != NULL) {
3661 error = VOP_LOCK1(vp1, LK_EXCLUSIVE | LK_NOWAIT,
3662 __FILE__, __LINE__);
3667 vn_lock_pair_pause("vlp2");
3669 vn_lock(vp1, LK_EXCLUSIVE | LK_RETRY);
3674 ASSERT_VOP_ELOCKED(vp1, "vp1 ret");
3676 ASSERT_VOP_ELOCKED(vp2, "vp2 ret");
3680 vn_lktype_write(struct mount *mp, struct vnode *vp)
3682 if (MNT_SHARED_WRITES(mp) ||
3683 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount)))
3685 return (LK_EXCLUSIVE);