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>
74 #include <sys/sleepqueue.h>
75 #include <sys/sysctl.h>
76 #include <sys/ttycom.h>
78 #include <sys/syslog.h>
79 #include <sys/unistd.h>
82 #include <security/audit/audit.h>
83 #include <security/mac/mac_framework.h>
86 #include <vm/vm_extern.h>
88 #include <vm/vm_map.h>
89 #include <vm/vm_object.h>
90 #include <vm/vm_page.h>
91 #include <vm/vm_pager.h>
94 #include <sys/pmckern.h>
97 static fo_rdwr_t vn_read;
98 static fo_rdwr_t vn_write;
99 static fo_rdwr_t vn_io_fault;
100 static fo_truncate_t vn_truncate;
101 static fo_ioctl_t vn_ioctl;
102 static fo_poll_t vn_poll;
103 static fo_kqfilter_t vn_kqfilter;
104 static fo_stat_t vn_statfile;
105 static fo_close_t vn_closefile;
106 static fo_mmap_t vn_mmap;
107 static fo_fallocate_t vn_fallocate;
109 struct fileops vnops = {
110 .fo_read = vn_io_fault,
111 .fo_write = vn_io_fault,
112 .fo_truncate = vn_truncate,
113 .fo_ioctl = vn_ioctl,
115 .fo_kqfilter = vn_kqfilter,
116 .fo_stat = vn_statfile,
117 .fo_close = vn_closefile,
118 .fo_chmod = vn_chmod,
119 .fo_chown = vn_chown,
120 .fo_sendfile = vn_sendfile,
122 .fo_fill_kinfo = vn_fill_kinfo,
124 .fo_fallocate = vn_fallocate,
125 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE
128 static const int io_hold_cnt = 16;
129 static int vn_io_fault_enable = 1;
130 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW,
131 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance");
132 static int vn_io_fault_prefault = 0;
133 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RW,
134 &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting");
135 static u_long vn_io_faults_cnt;
136 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD,
137 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers");
140 * Returns true if vn_io_fault mode of handling the i/o request should
144 do_vn_io_fault(struct vnode *vp, struct uio *uio)
148 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG &&
149 (mp = vp->v_mount) != NULL &&
150 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable);
154 * Structure used to pass arguments to vn_io_fault1(), to do either
155 * file- or vnode-based I/O calls.
157 struct vn_io_fault_args {
165 struct fop_args_tag {
169 struct vop_args_tag {
175 static int vn_io_fault1(struct vnode *vp, struct uio *uio,
176 struct vn_io_fault_args *args, struct thread *td);
179 vn_open(struct nameidata *ndp, int *flagp, int cmode, struct file *fp)
181 struct thread *td = ndp->ni_cnd.cn_thread;
183 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp));
187 * Common code for vnode open operations via a name lookup.
188 * Lookup the vnode and invoke VOP_CREATE if needed.
189 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
191 * Note that this does NOT free nameidata for the successful case,
192 * due to the NDINIT being done elsewhere.
195 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags,
196 struct ucred *cred, struct file *fp)
200 struct thread *td = ndp->ni_cnd.cn_thread;
202 struct vattr *vap = &vat;
207 if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT |
208 O_EXCL | O_DIRECTORY))
210 else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) {
211 ndp->ni_cnd.cn_nameiop = CREATE;
213 * Set NOCACHE to avoid flushing the cache when
214 * rolling in many files at once.
216 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF | NOCACHE;
217 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
218 ndp->ni_cnd.cn_flags |= FOLLOW;
219 if ((fmode & O_BENEATH) != 0)
220 ndp->ni_cnd.cn_flags |= BENEATH;
221 if (!(vn_open_flags & VN_OPEN_NOAUDIT))
222 ndp->ni_cnd.cn_flags |= AUDITVNODE1;
223 if (vn_open_flags & VN_OPEN_NOCAPCHECK)
224 ndp->ni_cnd.cn_flags |= NOCAPCHECK;
225 if ((vn_open_flags & VN_OPEN_INVFS) == 0)
227 if ((error = namei(ndp)) != 0)
229 if (ndp->ni_vp == NULL) {
232 vap->va_mode = cmode;
234 vap->va_vaflags |= VA_EXCLUSIVE;
235 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) {
236 NDFREE(ndp, NDF_ONLY_PNBUF);
238 if ((error = vn_start_write(NULL, &mp,
239 V_XSLEEP | PCATCH)) != 0)
243 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0)
244 ndp->ni_cnd.cn_flags |= MAKEENTRY;
246 error = mac_vnode_check_create(cred, ndp->ni_dvp,
250 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
253 vn_finished_write(mp);
255 NDFREE(ndp, NDF_ONLY_PNBUF);
261 if (ndp->ni_dvp == ndp->ni_vp)
267 if (fmode & O_EXCL) {
271 if (vp->v_type == VDIR) {
278 ndp->ni_cnd.cn_nameiop = LOOKUP;
279 ndp->ni_cnd.cn_flags = ISOPEN |
280 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF;
281 if (!(fmode & FWRITE))
282 ndp->ni_cnd.cn_flags |= LOCKSHARED;
283 if ((fmode & O_BENEATH) != 0)
284 ndp->ni_cnd.cn_flags |= BENEATH;
285 if (!(vn_open_flags & VN_OPEN_NOAUDIT))
286 ndp->ni_cnd.cn_flags |= AUDITVNODE1;
287 if (vn_open_flags & VN_OPEN_NOCAPCHECK)
288 ndp->ni_cnd.cn_flags |= NOCAPCHECK;
289 if ((error = namei(ndp)) != 0)
293 error = vn_open_vnode(vp, fmode, cred, td, fp);
299 NDFREE(ndp, NDF_ONLY_PNBUF);
307 vn_open_vnode_advlock(struct vnode *vp, int fmode, struct file *fp)
310 int error, lock_flags, type;
312 ASSERT_VOP_LOCKED(vp, "vn_open_vnode_advlock");
313 if ((fmode & (O_EXLOCK | O_SHLOCK)) == 0)
315 KASSERT(fp != NULL, ("open with flock requires fp"));
316 if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE)
319 lock_flags = VOP_ISLOCKED(vp);
322 lf.l_whence = SEEK_SET;
325 lf.l_type = (fmode & O_EXLOCK) != 0 ? F_WRLCK : F_RDLCK;
327 if ((fmode & FNONBLOCK) == 0)
329 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type);
331 fp->f_flag |= FHASLOCK;
333 vn_lock(vp, lock_flags | LK_RETRY);
334 if (error == 0 && VN_IS_DOOMED(vp))
340 * Common code for vnode open operations once a vnode is located.
341 * Check permissions, and call the VOP_OPEN routine.
344 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred,
345 struct thread *td, struct file *fp)
350 if (vp->v_type == VLNK)
352 if (vp->v_type == VSOCK)
354 if (vp->v_type != VDIR && fmode & O_DIRECTORY)
357 if (fmode & (FWRITE | O_TRUNC)) {
358 if (vp->v_type == VDIR)
366 if ((fmode & O_APPEND) && (fmode & FWRITE))
371 if (fmode & O_VERIFY)
373 error = mac_vnode_check_open(cred, vp, accmode);
377 accmode &= ~(VCREAT | VVERIFY);
379 if ((fmode & O_CREAT) == 0 && accmode != 0) {
380 error = VOP_ACCESS(vp, accmode, cred, td);
384 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
385 vn_lock(vp, LK_UPGRADE | LK_RETRY);
386 error = VOP_OPEN(vp, fmode, cred, td, fp);
390 error = vn_open_vnode_advlock(vp, fmode, fp);
391 if (error == 0 && (fmode & FWRITE) != 0) {
392 error = VOP_ADD_WRITECOUNT(vp, 1);
394 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
395 __func__, vp, vp->v_writecount);
400 * Error from advlock or VOP_ADD_WRITECOUNT() still requires
401 * calling VOP_CLOSE() to pair with earlier VOP_OPEN().
402 * Arrange for that by having fdrop() to use vn_closefile().
405 fp->f_flag |= FOPENFAILED;
407 if (fp->f_ops == &badfileops) {
408 fp->f_type = DTYPE_VNODE;
414 ASSERT_VOP_LOCKED(vp, "vn_open_vnode");
420 * Check for write permissions on the specified vnode.
421 * Prototype text segments cannot be written.
425 vn_writechk(struct vnode *vp)
428 ASSERT_VOP_LOCKED(vp, "vn_writechk");
430 * If there's shared text associated with
431 * the vnode, try to free it up once. If
432 * we fail, we can't allow writing.
444 vn_close1(struct vnode *vp, int flags, struct ucred *file_cred,
445 struct thread *td, bool keep_ref)
448 int error, lock_flags;
450 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 &&
451 MNT_EXTENDED_SHARED(vp->v_mount))
452 lock_flags = LK_SHARED;
454 lock_flags = LK_EXCLUSIVE;
456 vn_start_write(vp, &mp, V_WAIT);
457 vn_lock(vp, lock_flags | LK_RETRY);
458 AUDIT_ARG_VNODE1(vp);
459 if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) {
460 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
461 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
462 __func__, vp, vp->v_writecount);
464 error = VOP_CLOSE(vp, flags, file_cred, td);
469 vn_finished_write(mp);
474 vn_close(struct vnode *vp, int flags, struct ucred *file_cred,
478 return (vn_close1(vp, flags, file_cred, td, false));
482 * Heuristic to detect sequential operation.
485 sequential_heuristic(struct uio *uio, struct file *fp)
488 ASSERT_VOP_LOCKED(fp->f_vnode, __func__);
489 if (fp->f_flag & FRDAHEAD)
490 return (fp->f_seqcount << IO_SEQSHIFT);
493 * Offset 0 is handled specially. open() sets f_seqcount to 1 so
494 * that the first I/O is normally considered to be slightly
495 * sequential. Seeking to offset 0 doesn't change sequentiality
496 * unless previous seeks have reduced f_seqcount to 0, in which
497 * case offset 0 is not special.
499 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) ||
500 uio->uio_offset == fp->f_nextoff) {
502 * f_seqcount is in units of fixed-size blocks so that it
503 * depends mainly on the amount of sequential I/O and not
504 * much on the number of sequential I/O's. The fixed size
505 * of 16384 is hard-coded here since it is (not quite) just
506 * a magic size that works well here. This size is more
507 * closely related to the best I/O size for real disks than
508 * to any block size used by software.
510 if (uio->uio_resid >= IO_SEQMAX * 16384)
511 fp->f_seqcount = IO_SEQMAX;
513 fp->f_seqcount += howmany(uio->uio_resid, 16384);
514 if (fp->f_seqcount > IO_SEQMAX)
515 fp->f_seqcount = IO_SEQMAX;
517 return (fp->f_seqcount << IO_SEQSHIFT);
520 /* Not sequential. Quickly draw-down sequentiality. */
521 if (fp->f_seqcount > 1)
529 * Package up an I/O request on a vnode into a uio and do it.
532 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset,
533 enum uio_seg segflg, int ioflg, struct ucred *active_cred,
534 struct ucred *file_cred, ssize_t *aresid, struct thread *td)
541 struct vn_io_fault_args args;
542 int error, lock_flags;
544 if (offset < 0 && vp->v_type != VCHR)
546 auio.uio_iov = &aiov;
548 aiov.iov_base = base;
550 auio.uio_resid = len;
551 auio.uio_offset = offset;
552 auio.uio_segflg = segflg;
557 if ((ioflg & IO_NODELOCKED) == 0) {
558 if ((ioflg & IO_RANGELOCKED) == 0) {
559 if (rw == UIO_READ) {
560 rl_cookie = vn_rangelock_rlock(vp, offset,
563 rl_cookie = vn_rangelock_wlock(vp, offset,
569 if (rw == UIO_WRITE) {
570 if (vp->v_type != VCHR &&
571 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH))
574 if (MNT_SHARED_WRITES(mp) ||
575 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount)))
576 lock_flags = LK_SHARED;
578 lock_flags = LK_EXCLUSIVE;
580 lock_flags = LK_SHARED;
581 vn_lock(vp, lock_flags | LK_RETRY);
585 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
587 if ((ioflg & IO_NOMACCHECK) == 0) {
589 error = mac_vnode_check_read(active_cred, file_cred,
592 error = mac_vnode_check_write(active_cred, file_cred,
597 if (file_cred != NULL)
601 if (do_vn_io_fault(vp, &auio)) {
602 args.kind = VN_IO_FAULT_VOP;
605 args.args.vop_args.vp = vp;
606 error = vn_io_fault1(vp, &auio, &args, td);
607 } else if (rw == UIO_READ) {
608 error = VOP_READ(vp, &auio, ioflg, cred);
609 } else /* if (rw == UIO_WRITE) */ {
610 error = VOP_WRITE(vp, &auio, ioflg, cred);
614 *aresid = auio.uio_resid;
616 if (auio.uio_resid && error == 0)
618 if ((ioflg & IO_NODELOCKED) == 0) {
621 vn_finished_write(mp);
624 if (rl_cookie != NULL)
625 vn_rangelock_unlock(vp, rl_cookie);
630 * Package up an I/O request on a vnode into a uio and do it. The I/O
631 * request is split up into smaller chunks and we try to avoid saturating
632 * the buffer cache while potentially holding a vnode locked, so we
633 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield()
634 * to give other processes a chance to lock the vnode (either other processes
635 * core'ing the same binary, or unrelated processes scanning the directory).
638 vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, void *base, size_t len,
639 off_t offset, enum uio_seg segflg, int ioflg, struct ucred *active_cred,
640 struct ucred *file_cred, size_t *aresid, struct thread *td)
649 * Force `offset' to a multiple of MAXBSIZE except possibly
650 * for the first chunk, so that filesystems only need to
651 * write full blocks except possibly for the first and last
654 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE;
658 if (rw != UIO_READ && vp->v_type == VREG)
661 error = vn_rdwr(rw, vp, base, chunk, offset, segflg,
662 ioflg, active_cred, file_cred, &iaresid, td);
663 len -= chunk; /* aresid calc already includes length */
667 base = (char *)base + chunk;
668 kern_yield(PRI_USER);
671 *aresid = len + iaresid;
675 #if OFF_MAX <= LONG_MAX
677 foffset_lock(struct file *fp, int flags)
679 volatile short *flagsp;
683 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
685 if ((flags & FOF_NOLOCK) != 0)
686 return (atomic_load_long(&fp->f_offset));
689 * According to McKusick the vn lock was protecting f_offset here.
690 * It is now protected by the FOFFSET_LOCKED flag.
692 flagsp = &fp->f_vnread_flags;
693 if (atomic_cmpset_acq_16(flagsp, 0, FOFFSET_LOCKED))
694 return (atomic_load_long(&fp->f_offset));
696 sleepq_lock(&fp->f_vnread_flags);
697 state = atomic_load_16(flagsp);
699 if ((state & FOFFSET_LOCKED) == 0) {
700 if (!atomic_fcmpset_acq_16(flagsp, &state,
705 if ((state & FOFFSET_LOCK_WAITING) == 0) {
706 if (!atomic_fcmpset_acq_16(flagsp, &state,
707 state | FOFFSET_LOCK_WAITING))
711 sleepq_add(&fp->f_vnread_flags, NULL, "vofflock", 0, 0);
712 sleepq_wait(&fp->f_vnread_flags, PUSER -1);
714 sleepq_lock(&fp->f_vnread_flags);
715 state = atomic_load_16(flagsp);
717 res = atomic_load_long(&fp->f_offset);
718 sleepq_release(&fp->f_vnread_flags);
723 foffset_unlock(struct file *fp, off_t val, int flags)
725 volatile short *flagsp;
728 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
730 if ((flags & FOF_NOUPDATE) == 0)
731 atomic_store_long(&fp->f_offset, val);
732 if ((flags & FOF_NEXTOFF) != 0)
735 if ((flags & FOF_NOLOCK) != 0)
738 flagsp = &fp->f_vnread_flags;
739 state = atomic_load_16(flagsp);
740 if ((state & FOFFSET_LOCK_WAITING) == 0 &&
741 atomic_cmpset_rel_16(flagsp, state, 0))
744 sleepq_lock(&fp->f_vnread_flags);
745 MPASS((fp->f_vnread_flags & FOFFSET_LOCKED) != 0);
746 MPASS((fp->f_vnread_flags & FOFFSET_LOCK_WAITING) != 0);
747 fp->f_vnread_flags = 0;
748 sleepq_broadcast(&fp->f_vnread_flags, SLEEPQ_SLEEP, 0, 0);
749 sleepq_release(&fp->f_vnread_flags);
753 foffset_lock(struct file *fp, int flags)
758 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
760 mtxp = mtx_pool_find(mtxpool_sleep, fp);
762 if ((flags & FOF_NOLOCK) == 0) {
763 while (fp->f_vnread_flags & FOFFSET_LOCKED) {
764 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING;
765 msleep(&fp->f_vnread_flags, mtxp, PUSER -1,
768 fp->f_vnread_flags |= FOFFSET_LOCKED;
776 foffset_unlock(struct file *fp, off_t val, int flags)
780 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
782 mtxp = mtx_pool_find(mtxpool_sleep, fp);
784 if ((flags & FOF_NOUPDATE) == 0)
786 if ((flags & FOF_NEXTOFF) != 0)
788 if ((flags & FOF_NOLOCK) == 0) {
789 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0,
790 ("Lost FOFFSET_LOCKED"));
791 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING)
792 wakeup(&fp->f_vnread_flags);
793 fp->f_vnread_flags = 0;
800 foffset_lock_uio(struct file *fp, struct uio *uio, int flags)
803 if ((flags & FOF_OFFSET) == 0)
804 uio->uio_offset = foffset_lock(fp, flags);
808 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags)
811 if ((flags & FOF_OFFSET) == 0)
812 foffset_unlock(fp, uio->uio_offset, flags);
816 get_advice(struct file *fp, struct uio *uio)
821 ret = POSIX_FADV_NORMAL;
822 if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG)
825 mtxp = mtx_pool_find(mtxpool_sleep, fp);
827 if (fp->f_advice != NULL &&
828 uio->uio_offset >= fp->f_advice->fa_start &&
829 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end)
830 ret = fp->f_advice->fa_advice;
836 * File table vnode read routine.
839 vn_read(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
847 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
849 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
852 if (fp->f_flag & FNONBLOCK)
854 if (fp->f_flag & O_DIRECT)
856 advice = get_advice(fp, uio);
857 vn_lock(vp, LK_SHARED | LK_RETRY);
860 case POSIX_FADV_NORMAL:
861 case POSIX_FADV_SEQUENTIAL:
862 case POSIX_FADV_NOREUSE:
863 ioflag |= sequential_heuristic(uio, fp);
865 case POSIX_FADV_RANDOM:
866 /* Disable read-ahead for random I/O. */
869 orig_offset = uio->uio_offset;
872 error = mac_vnode_check_read(active_cred, fp->f_cred, vp);
875 error = VOP_READ(vp, uio, ioflag, fp->f_cred);
876 fp->f_nextoff = uio->uio_offset;
878 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
879 orig_offset != uio->uio_offset)
881 * Use POSIX_FADV_DONTNEED to flush pages and buffers
882 * for the backing file after a POSIX_FADV_NOREUSE
885 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
886 POSIX_FADV_DONTNEED);
891 * File table vnode write routine.
894 vn_write(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
900 int error, ioflag, lock_flags;
903 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
905 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
907 if (vp->v_type == VREG)
910 if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
912 if (fp->f_flag & FNONBLOCK)
914 if (fp->f_flag & O_DIRECT)
916 if ((fp->f_flag & O_FSYNC) ||
917 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
920 if (vp->v_type != VCHR &&
921 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
924 advice = get_advice(fp, uio);
926 if (MNT_SHARED_WRITES(mp) ||
927 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) {
928 lock_flags = LK_SHARED;
930 lock_flags = LK_EXCLUSIVE;
933 vn_lock(vp, lock_flags | LK_RETRY);
935 case POSIX_FADV_NORMAL:
936 case POSIX_FADV_SEQUENTIAL:
937 case POSIX_FADV_NOREUSE:
938 ioflag |= sequential_heuristic(uio, fp);
940 case POSIX_FADV_RANDOM:
941 /* XXX: Is this correct? */
944 orig_offset = uio->uio_offset;
947 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
950 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred);
951 fp->f_nextoff = uio->uio_offset;
953 if (vp->v_type != VCHR)
954 vn_finished_write(mp);
955 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
956 orig_offset != uio->uio_offset)
958 * Use POSIX_FADV_DONTNEED to flush pages and buffers
959 * for the backing file after a POSIX_FADV_NOREUSE
962 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
963 POSIX_FADV_DONTNEED);
969 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to
970 * prevent the following deadlock:
972 * Assume that the thread A reads from the vnode vp1 into userspace
973 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is
974 * currently not resident, then system ends up with the call chain
975 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] ->
976 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2)
977 * which establishes lock order vp1->vn_lock, then vp2->vn_lock.
978 * If, at the same time, thread B reads from vnode vp2 into buffer buf2
979 * backed by the pages of vnode vp1, and some page in buf2 is not
980 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock.
982 * To prevent the lock order reversal and deadlock, vn_io_fault() does
983 * not allow page faults to happen during VOP_READ() or VOP_WRITE().
984 * Instead, it first tries to do the whole range i/o with pagefaults
985 * disabled. If all pages in the i/o buffer are resident and mapped,
986 * VOP will succeed (ignoring the genuine filesystem errors).
987 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do
988 * i/o in chunks, with all pages in the chunk prefaulted and held
989 * using vm_fault_quick_hold_pages().
991 * Filesystems using this deadlock avoidance scheme should use the
992 * array of the held pages from uio, saved in the curthread->td_ma,
993 * instead of doing uiomove(). A helper function
994 * vn_io_fault_uiomove() converts uiomove request into
995 * uiomove_fromphys() over td_ma array.
997 * Since vnode locks do not cover the whole i/o anymore, rangelocks
998 * make the current i/o request atomic with respect to other i/os and
1003 * Decode vn_io_fault_args and perform the corresponding i/o.
1006 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio,
1012 save = vm_fault_disable_pagefaults();
1013 switch (args->kind) {
1014 case VN_IO_FAULT_FOP:
1015 error = (args->args.fop_args.doio)(args->args.fop_args.fp,
1016 uio, args->cred, args->flags, td);
1018 case VN_IO_FAULT_VOP:
1019 if (uio->uio_rw == UIO_READ) {
1020 error = VOP_READ(args->args.vop_args.vp, uio,
1021 args->flags, args->cred);
1022 } else if (uio->uio_rw == UIO_WRITE) {
1023 error = VOP_WRITE(args->args.vop_args.vp, uio,
1024 args->flags, args->cred);
1028 panic("vn_io_fault_doio: unknown kind of io %d %d",
1029 args->kind, uio->uio_rw);
1031 vm_fault_enable_pagefaults(save);
1036 vn_io_fault_touch(char *base, const struct uio *uio)
1041 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1))
1047 vn_io_fault_prefault_user(const struct uio *uio)
1050 const struct iovec *iov;
1055 KASSERT(uio->uio_segflg == UIO_USERSPACE,
1056 ("vn_io_fault_prefault userspace"));
1060 resid = uio->uio_resid;
1061 base = iov->iov_base;
1064 error = vn_io_fault_touch(base, uio);
1067 if (len < PAGE_SIZE) {
1069 error = vn_io_fault_touch(base + len - 1, uio);
1074 if (++i >= uio->uio_iovcnt)
1076 iov = uio->uio_iov + i;
1077 base = iov->iov_base;
1089 * Common code for vn_io_fault(), agnostic to the kind of i/o request.
1090 * Uses vn_io_fault_doio() to make the call to an actual i/o function.
1091 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request
1092 * into args and call vn_io_fault1() to handle faults during the user
1093 * mode buffer accesses.
1096 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args,
1099 vm_page_t ma[io_hold_cnt + 2];
1100 struct uio *uio_clone, short_uio;
1101 struct iovec short_iovec[1];
1102 vm_page_t *prev_td_ma;
1104 vm_offset_t addr, end;
1107 int error, cnt, saveheld, prev_td_ma_cnt;
1109 if (vn_io_fault_prefault) {
1110 error = vn_io_fault_prefault_user(uio);
1112 return (error); /* Or ignore ? */
1115 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ;
1118 * The UFS follows IO_UNIT directive and replays back both
1119 * uio_offset and uio_resid if an error is encountered during the
1120 * operation. But, since the iovec may be already advanced,
1121 * uio is still in an inconsistent state.
1123 * Cache a copy of the original uio, which is advanced to the redo
1124 * point using UIO_NOCOPY below.
1126 uio_clone = cloneuio(uio);
1127 resid = uio->uio_resid;
1129 short_uio.uio_segflg = UIO_USERSPACE;
1130 short_uio.uio_rw = uio->uio_rw;
1131 short_uio.uio_td = uio->uio_td;
1133 error = vn_io_fault_doio(args, uio, td);
1134 if (error != EFAULT)
1137 atomic_add_long(&vn_io_faults_cnt, 1);
1138 uio_clone->uio_segflg = UIO_NOCOPY;
1139 uiomove(NULL, resid - uio->uio_resid, uio_clone);
1140 uio_clone->uio_segflg = uio->uio_segflg;
1142 saveheld = curthread_pflags_set(TDP_UIOHELD);
1143 prev_td_ma = td->td_ma;
1144 prev_td_ma_cnt = td->td_ma_cnt;
1146 while (uio_clone->uio_resid != 0) {
1147 len = uio_clone->uio_iov->iov_len;
1149 KASSERT(uio_clone->uio_iovcnt >= 1,
1150 ("iovcnt underflow"));
1151 uio_clone->uio_iov++;
1152 uio_clone->uio_iovcnt--;
1155 if (len > io_hold_cnt * PAGE_SIZE)
1156 len = io_hold_cnt * PAGE_SIZE;
1157 addr = (uintptr_t)uio_clone->uio_iov->iov_base;
1158 end = round_page(addr + len);
1163 cnt = atop(end - trunc_page(addr));
1165 * A perfectly misaligned address and length could cause
1166 * both the start and the end of the chunk to use partial
1167 * page. +2 accounts for such a situation.
1169 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map,
1170 addr, len, prot, ma, io_hold_cnt + 2);
1175 short_uio.uio_iov = &short_iovec[0];
1176 short_iovec[0].iov_base = (void *)addr;
1177 short_uio.uio_iovcnt = 1;
1178 short_uio.uio_resid = short_iovec[0].iov_len = len;
1179 short_uio.uio_offset = uio_clone->uio_offset;
1181 td->td_ma_cnt = cnt;
1183 error = vn_io_fault_doio(args, &short_uio, td);
1184 vm_page_unhold_pages(ma, cnt);
1185 adv = len - short_uio.uio_resid;
1187 uio_clone->uio_iov->iov_base =
1188 (char *)uio_clone->uio_iov->iov_base + adv;
1189 uio_clone->uio_iov->iov_len -= adv;
1190 uio_clone->uio_resid -= adv;
1191 uio_clone->uio_offset += adv;
1193 uio->uio_resid -= adv;
1194 uio->uio_offset += adv;
1196 if (error != 0 || adv == 0)
1199 td->td_ma = prev_td_ma;
1200 td->td_ma_cnt = prev_td_ma_cnt;
1201 curthread_pflags_restore(saveheld);
1203 free(uio_clone, M_IOV);
1208 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred,
1209 int flags, struct thread *td)
1214 struct vn_io_fault_args args;
1217 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write;
1219 foffset_lock_uio(fp, uio, flags);
1220 if (do_vn_io_fault(vp, uio)) {
1221 args.kind = VN_IO_FAULT_FOP;
1222 args.args.fop_args.fp = fp;
1223 args.args.fop_args.doio = doio;
1224 args.cred = active_cred;
1225 args.flags = flags | FOF_OFFSET;
1226 if (uio->uio_rw == UIO_READ) {
1227 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset,
1228 uio->uio_offset + uio->uio_resid);
1229 } else if ((fp->f_flag & O_APPEND) != 0 ||
1230 (flags & FOF_OFFSET) == 0) {
1231 /* For appenders, punt and lock the whole range. */
1232 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1234 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset,
1235 uio->uio_offset + uio->uio_resid);
1237 error = vn_io_fault1(vp, uio, &args, td);
1238 vn_rangelock_unlock(vp, rl_cookie);
1240 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td);
1242 foffset_unlock_uio(fp, uio, flags);
1247 * Helper function to perform the requested uiomove operation using
1248 * the held pages for io->uio_iov[0].iov_base buffer instead of
1249 * copyin/copyout. Access to the pages with uiomove_fromphys()
1250 * instead of iov_base prevents page faults that could occur due to
1251 * pmap_collect() invalidating the mapping created by
1252 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or
1253 * object cleanup revoking the write access from page mappings.
1255 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove()
1256 * instead of plain uiomove().
1259 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio)
1261 struct uio transp_uio;
1262 struct iovec transp_iov[1];
1268 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1269 uio->uio_segflg != UIO_USERSPACE)
1270 return (uiomove(data, xfersize, uio));
1272 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1273 transp_iov[0].iov_base = data;
1274 transp_uio.uio_iov = &transp_iov[0];
1275 transp_uio.uio_iovcnt = 1;
1276 if (xfersize > uio->uio_resid)
1277 xfersize = uio->uio_resid;
1278 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize;
1279 transp_uio.uio_offset = 0;
1280 transp_uio.uio_segflg = UIO_SYSSPACE;
1282 * Since transp_iov points to data, and td_ma page array
1283 * corresponds to original uio->uio_iov, we need to invert the
1284 * direction of the i/o operation as passed to
1285 * uiomove_fromphys().
1287 switch (uio->uio_rw) {
1289 transp_uio.uio_rw = UIO_READ;
1292 transp_uio.uio_rw = UIO_WRITE;
1295 transp_uio.uio_td = uio->uio_td;
1296 error = uiomove_fromphys(td->td_ma,
1297 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK,
1298 xfersize, &transp_uio);
1299 adv = xfersize - transp_uio.uio_resid;
1301 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) -
1302 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT);
1304 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1306 td->td_ma_cnt -= pgadv;
1307 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv;
1308 uio->uio_iov->iov_len -= adv;
1309 uio->uio_resid -= adv;
1310 uio->uio_offset += adv;
1315 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize,
1319 vm_offset_t iov_base;
1323 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1324 uio->uio_segflg != UIO_USERSPACE)
1325 return (uiomove_fromphys(ma, offset, xfersize, uio));
1327 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1328 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize;
1329 iov_base = (vm_offset_t)uio->uio_iov->iov_base;
1330 switch (uio->uio_rw) {
1332 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma,
1336 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK,
1340 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT);
1342 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1344 td->td_ma_cnt -= pgadv;
1345 uio->uio_iov->iov_base = (char *)(iov_base + cnt);
1346 uio->uio_iov->iov_len -= cnt;
1347 uio->uio_resid -= cnt;
1348 uio->uio_offset += cnt;
1353 * File table truncate routine.
1356 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred,
1367 * Lock the whole range for truncation. Otherwise split i/o
1368 * might happen partly before and partly after the truncation.
1370 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1371 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
1374 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1375 AUDIT_ARG_VNODE1(vp);
1376 if (vp->v_type == VDIR) {
1381 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
1385 error = vn_truncate_locked(vp, length, (fp->f_flag & O_FSYNC) != 0,
1389 vn_finished_write(mp);
1391 vn_rangelock_unlock(vp, rl_cookie);
1396 * Truncate a file that is already locked.
1399 vn_truncate_locked(struct vnode *vp, off_t length, bool sync,
1405 error = VOP_ADD_WRITECOUNT(vp, 1);
1408 vattr.va_size = length;
1410 vattr.va_vaflags |= VA_SYNC;
1411 error = VOP_SETATTR(vp, &vattr, cred);
1412 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
1418 * File table vnode stat routine.
1421 vn_statfile(struct file *fp, struct stat *sb, struct ucred *active_cred,
1424 struct vnode *vp = fp->f_vnode;
1427 vn_lock(vp, LK_SHARED | LK_RETRY);
1428 error = vn_stat(vp, sb, active_cred, fp->f_cred, td);
1435 * Stat a vnode; implementation for the stat syscall
1438 vn_stat(struct vnode *vp, struct stat *sb, struct ucred *active_cred,
1439 struct ucred *file_cred, struct thread *td)
1446 AUDIT_ARG_VNODE1(vp);
1448 error = mac_vnode_check_stat(active_cred, file_cred, vp);
1456 * Initialize defaults for new and unusual fields, so that file
1457 * systems which don't support these fields don't need to know
1460 vap->va_birthtime.tv_sec = -1;
1461 vap->va_birthtime.tv_nsec = 0;
1462 vap->va_fsid = VNOVAL;
1463 vap->va_rdev = NODEV;
1465 error = VOP_GETATTR(vp, vap, active_cred);
1470 * Zero the spare stat fields
1472 bzero(sb, sizeof *sb);
1475 * Copy from vattr table
1477 if (vap->va_fsid != VNOVAL)
1478 sb->st_dev = vap->va_fsid;
1480 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0];
1481 sb->st_ino = vap->va_fileid;
1482 mode = vap->va_mode;
1483 switch (vap->va_type) {
1509 sb->st_nlink = vap->va_nlink;
1510 sb->st_uid = vap->va_uid;
1511 sb->st_gid = vap->va_gid;
1512 sb->st_rdev = vap->va_rdev;
1513 if (vap->va_size > OFF_MAX)
1515 sb->st_size = vap->va_size;
1516 sb->st_atim.tv_sec = vap->va_atime.tv_sec;
1517 sb->st_atim.tv_nsec = vap->va_atime.tv_nsec;
1518 sb->st_mtim.tv_sec = vap->va_mtime.tv_sec;
1519 sb->st_mtim.tv_nsec = vap->va_mtime.tv_nsec;
1520 sb->st_ctim.tv_sec = vap->va_ctime.tv_sec;
1521 sb->st_ctim.tv_nsec = vap->va_ctime.tv_nsec;
1522 sb->st_birthtim.tv_sec = vap->va_birthtime.tv_sec;
1523 sb->st_birthtim.tv_nsec = vap->va_birthtime.tv_nsec;
1526 * According to www.opengroup.org, the meaning of st_blksize is
1527 * "a filesystem-specific preferred I/O block size for this
1528 * object. In some filesystem types, this may vary from file
1530 * Use miminum/default of PAGE_SIZE (e.g. for VCHR).
1533 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize);
1535 sb->st_flags = vap->va_flags;
1536 if (priv_check_cred_vfs_generation(td->td_ucred))
1539 sb->st_gen = vap->va_gen;
1541 sb->st_blocks = vap->va_bytes / S_BLKSIZE;
1546 * File table vnode ioctl routine.
1549 vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
1554 struct fiobmap2_arg *bmarg;
1558 switch (vp->v_type) {
1563 vn_lock(vp, LK_SHARED | LK_RETRY);
1564 error = VOP_GETATTR(vp, &vattr, active_cred);
1567 *(int *)data = vattr.va_size - fp->f_offset;
1570 bmarg = (struct fiobmap2_arg *)data;
1571 vn_lock(vp, LK_SHARED | LK_RETRY);
1573 error = mac_vnode_check_read(active_cred, fp->f_cred,
1577 error = VOP_BMAP(vp, bmarg->bn, NULL,
1578 &bmarg->bn, &bmarg->runp, &bmarg->runb);
1585 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1590 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1598 * File table vnode poll routine.
1601 vn_poll(struct file *fp, int events, struct ucred *active_cred,
1609 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1610 AUDIT_ARG_VNODE1(vp);
1611 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp);
1616 error = VOP_POLL(vp, events, fp->f_cred, td);
1621 * Acquire the requested lock and then check for validity. LK_RETRY
1622 * permits vn_lock to return doomed vnodes.
1624 static int __noinline
1625 _vn_lock_fallback(struct vnode *vp, int flags, const char *file, int line,
1629 KASSERT((flags & LK_RETRY) == 0 || error == 0,
1630 ("vn_lock: error %d incompatible with flags %#x", error, flags));
1633 VNASSERT(VN_IS_DOOMED(vp), vp, ("vnode not doomed"));
1635 if ((flags & LK_RETRY) == 0) {
1646 * Nothing to do if we got the lock.
1652 * Interlock was dropped by the call in _vn_lock.
1654 flags &= ~LK_INTERLOCK;
1656 error = VOP_LOCK1(vp, flags, file, line);
1657 } while (error != 0);
1662 _vn_lock(struct vnode *vp, int flags, const char *file, int line)
1666 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
1667 ("vn_lock: no locktype (%d passed)", flags));
1668 VNPASS(vp->v_holdcnt > 0, vp);
1669 error = VOP_LOCK1(vp, flags, file, line);
1670 if (__predict_false(error != 0 || VN_IS_DOOMED(vp)))
1671 return (_vn_lock_fallback(vp, flags, file, line, error));
1676 * File table vnode close routine.
1679 vn_closefile(struct file *fp, struct thread *td)
1687 fp->f_ops = &badfileops;
1688 ref= (fp->f_flag & FHASLOCK) != 0 && fp->f_type == DTYPE_VNODE;
1690 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref);
1692 if (__predict_false(ref)) {
1693 lf.l_whence = SEEK_SET;
1696 lf.l_type = F_UNLCK;
1697 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK);
1704 * Preparing to start a filesystem write operation. If the operation is
1705 * permitted, then we bump the count of operations in progress and
1706 * proceed. If a suspend request is in progress, we wait until the
1707 * suspension is over, and then proceed.
1710 vn_start_write_refed(struct mount *mp, int flags, bool mplocked)
1714 if (__predict_true(!mplocked) && (flags & V_XSLEEP) == 0 &&
1715 vfs_op_thread_enter(mp)) {
1716 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0);
1717 vfs_mp_count_add_pcpu(mp, writeopcount, 1);
1718 vfs_op_thread_exit(mp);
1723 mtx_assert(MNT_MTX(mp), MA_OWNED);
1730 * Check on status of suspension.
1732 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 ||
1733 mp->mnt_susp_owner != curthread) {
1734 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ?
1735 (flags & PCATCH) : 0) | (PUSER - 1);
1736 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1737 if (flags & V_NOWAIT) {
1738 error = EWOULDBLOCK;
1741 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags,
1747 if (flags & V_XSLEEP)
1749 mp->mnt_writeopcount++;
1751 if (error != 0 || (flags & V_XSLEEP) != 0)
1758 vn_start_write(struct vnode *vp, struct mount **mpp, int flags)
1763 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1764 ("V_MNTREF requires mp"));
1768 * If a vnode is provided, get and return the mount point that
1769 * to which it will write.
1772 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1774 if (error != EOPNOTSUPP)
1779 if ((mp = *mpp) == NULL)
1783 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1785 * As long as a vnode is not provided we need to acquire a
1786 * refcount for the provided mountpoint too, in order to
1787 * emulate a vfs_ref().
1789 if (vp == NULL && (flags & V_MNTREF) == 0)
1792 return (vn_start_write_refed(mp, flags, false));
1796 * Secondary suspension. Used by operations such as vop_inactive
1797 * routines that are needed by the higher level functions. These
1798 * are allowed to proceed until all the higher level functions have
1799 * completed (indicated by mnt_writeopcount dropping to zero). At that
1800 * time, these operations are halted until the suspension is over.
1803 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags)
1808 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1809 ("V_MNTREF requires mp"));
1813 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1815 if (error != EOPNOTSUPP)
1821 * If we are not suspended or have not yet reached suspended
1822 * mode, then let the operation proceed.
1824 if ((mp = *mpp) == NULL)
1828 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1830 * As long as a vnode is not provided we need to acquire a
1831 * refcount for the provided mountpoint too, in order to
1832 * emulate a vfs_ref().
1835 if (vp == NULL && (flags & V_MNTREF) == 0)
1837 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) {
1838 mp->mnt_secondary_writes++;
1839 mp->mnt_secondary_accwrites++;
1843 if (flags & V_NOWAIT) {
1846 return (EWOULDBLOCK);
1849 * Wait for the suspension to finish.
1851 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP |
1852 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0),
1861 * Filesystem write operation has completed. If we are suspending and this
1862 * operation is the last one, notify the suspender that the suspension is
1866 vn_finished_write(struct mount *mp)
1873 if (vfs_op_thread_enter(mp)) {
1874 vfs_mp_count_sub_pcpu(mp, writeopcount, 1);
1875 vfs_mp_count_sub_pcpu(mp, ref, 1);
1876 vfs_op_thread_exit(mp);
1881 vfs_assert_mount_counters(mp);
1883 c = --mp->mnt_writeopcount;
1884 if (mp->mnt_vfs_ops == 0) {
1885 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0);
1890 vfs_dump_mount_counters(mp);
1891 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && c == 0)
1892 wakeup(&mp->mnt_writeopcount);
1897 * Filesystem secondary write operation has completed. If we are
1898 * suspending and this operation is the last one, notify the suspender
1899 * that the suspension is now in effect.
1902 vn_finished_secondary_write(struct mount *mp)
1908 mp->mnt_secondary_writes--;
1909 if (mp->mnt_secondary_writes < 0)
1910 panic("vn_finished_secondary_write: neg cnt");
1911 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
1912 mp->mnt_secondary_writes <= 0)
1913 wakeup(&mp->mnt_secondary_writes);
1918 * Request a filesystem to suspend write operations.
1921 vfs_write_suspend(struct mount *mp, int flags)
1928 vfs_assert_mount_counters(mp);
1929 if (mp->mnt_susp_owner == curthread) {
1930 vfs_op_exit_locked(mp);
1934 while (mp->mnt_kern_flag & MNTK_SUSPEND)
1935 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0);
1938 * Unmount holds a write reference on the mount point. If we
1939 * own busy reference and drain for writers, we deadlock with
1940 * the reference draining in the unmount path. Callers of
1941 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if
1942 * vfs_busy() reference is owned and caller is not in the
1945 if ((flags & VS_SKIP_UNMOUNT) != 0 &&
1946 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) {
1947 vfs_op_exit_locked(mp);
1952 mp->mnt_kern_flag |= MNTK_SUSPEND;
1953 mp->mnt_susp_owner = curthread;
1954 if (mp->mnt_writeopcount > 0)
1955 (void) msleep(&mp->mnt_writeopcount,
1956 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0);
1959 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) {
1960 vfs_write_resume(mp, 0);
1961 /* vfs_write_resume does vfs_op_exit() for us */
1967 * Request a filesystem to resume write operations.
1970 vfs_write_resume(struct mount *mp, int flags)
1974 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1975 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner"));
1976 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 |
1978 mp->mnt_susp_owner = NULL;
1979 wakeup(&mp->mnt_writeopcount);
1980 wakeup(&mp->mnt_flag);
1981 curthread->td_pflags &= ~TDP_IGNSUSP;
1982 if ((flags & VR_START_WRITE) != 0) {
1984 mp->mnt_writeopcount++;
1987 if ((flags & VR_NO_SUSPCLR) == 0)
1990 } else if ((flags & VR_START_WRITE) != 0) {
1992 vn_start_write_refed(mp, 0, true);
1999 * Helper loop around vfs_write_suspend() for filesystem unmount VFS
2003 vfs_write_suspend_umnt(struct mount *mp)
2007 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0,
2008 ("vfs_write_suspend_umnt: recursed"));
2010 /* dounmount() already called vn_start_write(). */
2012 vn_finished_write(mp);
2013 error = vfs_write_suspend(mp, 0);
2015 vn_start_write(NULL, &mp, V_WAIT);
2019 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0)
2022 vn_start_write(NULL, &mp, V_WAIT);
2024 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2);
2025 wakeup(&mp->mnt_flag);
2027 curthread->td_pflags |= TDP_IGNSUSP;
2032 * Implement kqueues for files by translating it to vnode operation.
2035 vn_kqfilter(struct file *fp, struct knote *kn)
2038 return (VOP_KQFILTER(fp->f_vnode, kn));
2042 * Simplified in-kernel wrapper calls for extended attribute access.
2043 * Both calls pass in a NULL credential, authorizing as "kernel" access.
2044 * Set IO_NODELOCKED in ioflg if the vnode is already locked.
2047 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace,
2048 const char *attrname, int *buflen, char *buf, struct thread *td)
2054 iov.iov_len = *buflen;
2057 auio.uio_iov = &iov;
2058 auio.uio_iovcnt = 1;
2059 auio.uio_rw = UIO_READ;
2060 auio.uio_segflg = UIO_SYSSPACE;
2062 auio.uio_offset = 0;
2063 auio.uio_resid = *buflen;
2065 if ((ioflg & IO_NODELOCKED) == 0)
2066 vn_lock(vp, LK_SHARED | LK_RETRY);
2068 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2070 /* authorize attribute retrieval as kernel */
2071 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL,
2074 if ((ioflg & IO_NODELOCKED) == 0)
2078 *buflen = *buflen - auio.uio_resid;
2085 * XXX failure mode if partially written?
2088 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace,
2089 const char *attrname, int buflen, char *buf, struct thread *td)
2096 iov.iov_len = buflen;
2099 auio.uio_iov = &iov;
2100 auio.uio_iovcnt = 1;
2101 auio.uio_rw = UIO_WRITE;
2102 auio.uio_segflg = UIO_SYSSPACE;
2104 auio.uio_offset = 0;
2105 auio.uio_resid = buflen;
2107 if ((ioflg & IO_NODELOCKED) == 0) {
2108 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2110 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2113 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2115 /* authorize attribute setting as kernel */
2116 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td);
2118 if ((ioflg & IO_NODELOCKED) == 0) {
2119 vn_finished_write(mp);
2127 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace,
2128 const char *attrname, struct thread *td)
2133 if ((ioflg & IO_NODELOCKED) == 0) {
2134 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2136 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2139 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2141 /* authorize attribute removal as kernel */
2142 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td);
2143 if (error == EOPNOTSUPP)
2144 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL,
2147 if ((ioflg & IO_NODELOCKED) == 0) {
2148 vn_finished_write(mp);
2156 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags,
2160 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp));
2164 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp)
2167 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino,
2172 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg,
2173 int lkflags, struct vnode **rvp)
2178 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get");
2180 ltype = VOP_ISLOCKED(vp);
2181 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED,
2182 ("vn_vget_ino: vp not locked"));
2183 error = vfs_busy(mp, MBF_NOWAIT);
2187 error = vfs_busy(mp, 0);
2188 vn_lock(vp, ltype | LK_RETRY);
2192 if (VN_IS_DOOMED(vp)) {
2198 error = alloc(mp, alloc_arg, lkflags, rvp);
2200 if (error != 0 || *rvp != vp)
2201 vn_lock(vp, ltype | LK_RETRY);
2202 if (VN_IS_DOOMED(vp)) {
2215 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio,
2219 if (vp->v_type != VREG || td == NULL)
2221 if ((uoff_t)uio->uio_offset + uio->uio_resid >
2222 lim_cur(td, RLIMIT_FSIZE)) {
2223 PROC_LOCK(td->td_proc);
2224 kern_psignal(td->td_proc, SIGXFSZ);
2225 PROC_UNLOCK(td->td_proc);
2232 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
2239 vn_lock(vp, LK_SHARED | LK_RETRY);
2240 AUDIT_ARG_VNODE1(vp);
2243 return (setfmode(td, active_cred, vp, mode));
2247 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
2254 vn_lock(vp, LK_SHARED | LK_RETRY);
2255 AUDIT_ARG_VNODE1(vp);
2258 return (setfown(td, active_cred, vp, uid, gid));
2262 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end)
2266 if ((object = vp->v_object) == NULL)
2268 VM_OBJECT_WLOCK(object);
2269 vm_object_page_remove(object, start, end, 0);
2270 VM_OBJECT_WUNLOCK(object);
2274 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred)
2282 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
2283 ("Wrong command %lu", cmd));
2285 if (vn_lock(vp, LK_SHARED) != 0)
2287 if (vp->v_type != VREG) {
2291 error = VOP_GETATTR(vp, &va, cred);
2295 if (noff >= va.va_size) {
2299 bsize = vp->v_mount->mnt_stat.f_iosize;
2300 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize -
2302 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL);
2303 if (error == EOPNOTSUPP) {
2307 if ((bnp == -1 && cmd == FIOSEEKHOLE) ||
2308 (bnp != -1 && cmd == FIOSEEKDATA)) {
2315 if (noff > va.va_size)
2317 /* noff == va.va_size. There is an implicit hole at the end of file. */
2318 if (cmd == FIOSEEKDATA)
2328 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td)
2333 off_t foffset, size;
2336 cred = td->td_ucred;
2338 foffset = foffset_lock(fp, 0);
2339 noneg = (vp->v_type != VCHR);
2345 (offset > 0 && foffset > OFF_MAX - offset))) {
2352 vn_lock(vp, LK_SHARED | LK_RETRY);
2353 error = VOP_GETATTR(vp, &vattr, cred);
2359 * If the file references a disk device, then fetch
2360 * the media size and use that to determine the ending
2363 if (vattr.va_size == 0 && vp->v_type == VCHR &&
2364 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0)
2365 vattr.va_size = size;
2367 (vattr.va_size > OFF_MAX ||
2368 (offset > 0 && vattr.va_size > OFF_MAX - offset))) {
2372 offset += vattr.va_size;
2377 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td);
2378 if (error == ENOTTY)
2382 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td);
2383 if (error == ENOTTY)
2389 if (error == 0 && noneg && offset < 0)
2393 VFS_KNOTE_UNLOCKED(vp, 0);
2394 td->td_uretoff.tdu_off = offset;
2396 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0);
2401 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred,
2407 * Grant permission if the caller is the owner of the file, or
2408 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on
2409 * on the file. If the time pointer is null, then write
2410 * permission on the file is also sufficient.
2412 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes:
2413 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES
2414 * will be allowed to set the times [..] to the current
2417 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td);
2418 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0)
2419 error = VOP_ACCESS(vp, VWRITE, cred, td);
2424 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
2429 if (fp->f_type == DTYPE_FIFO)
2430 kif->kf_type = KF_TYPE_FIFO;
2432 kif->kf_type = KF_TYPE_VNODE;
2435 FILEDESC_SUNLOCK(fdp);
2436 error = vn_fill_kinfo_vnode(vp, kif);
2438 FILEDESC_SLOCK(fdp);
2443 vn_fill_junk(struct kinfo_file *kif)
2448 * Simulate vn_fullpath returning changing values for a given
2449 * vp during e.g. coredump.
2451 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1;
2452 olen = strlen(kif->kf_path);
2454 strcpy(&kif->kf_path[len - 1], "$");
2456 for (; olen < len; olen++)
2457 strcpy(&kif->kf_path[olen], "A");
2461 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif)
2464 char *fullpath, *freepath;
2467 kif->kf_un.kf_file.kf_file_type = vntype_to_kinfo(vp->v_type);
2470 error = vn_fullpath(curthread, vp, &fullpath, &freepath);
2472 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
2474 if (freepath != NULL)
2475 free(freepath, M_TEMP);
2477 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path,
2482 * Retrieve vnode attributes.
2484 va.va_fsid = VNOVAL;
2486 vn_lock(vp, LK_SHARED | LK_RETRY);
2487 error = VOP_GETATTR(vp, &va, curthread->td_ucred);
2491 if (va.va_fsid != VNOVAL)
2492 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid;
2494 kif->kf_un.kf_file.kf_file_fsid =
2495 vp->v_mount->mnt_stat.f_fsid.val[0];
2496 kif->kf_un.kf_file.kf_file_fsid_freebsd11 =
2497 kif->kf_un.kf_file.kf_file_fsid; /* truncate */
2498 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid;
2499 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode);
2500 kif->kf_un.kf_file.kf_file_size = va.va_size;
2501 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev;
2502 kif->kf_un.kf_file.kf_file_rdev_freebsd11 =
2503 kif->kf_un.kf_file.kf_file_rdev; /* truncate */
2508 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
2509 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
2513 struct pmckern_map_in pkm;
2519 boolean_t writecounted;
2522 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
2523 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
2525 * POSIX shared-memory objects are defined to have
2526 * kernel persistence, and are not defined to support
2527 * read(2)/write(2) -- or even open(2). Thus, we can
2528 * use MAP_ASYNC to trade on-disk coherence for speed.
2529 * The shm_open(3) library routine turns on the FPOSIXSHM
2530 * flag to request this behavior.
2532 if ((fp->f_flag & FPOSIXSHM) != 0)
2533 flags |= MAP_NOSYNC;
2538 * Ensure that file and memory protections are
2539 * compatible. Note that we only worry about
2540 * writability if mapping is shared; in this case,
2541 * current and max prot are dictated by the open file.
2542 * XXX use the vnode instead? Problem is: what
2543 * credentials do we use for determination? What if
2544 * proc does a setuid?
2547 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) {
2548 maxprot = VM_PROT_NONE;
2549 if ((prot & VM_PROT_EXECUTE) != 0)
2552 maxprot = VM_PROT_EXECUTE;
2553 if ((fp->f_flag & FREAD) != 0)
2554 maxprot |= VM_PROT_READ;
2555 else if ((prot & VM_PROT_READ) != 0)
2559 * If we are sharing potential changes via MAP_SHARED and we
2560 * are trying to get write permission although we opened it
2561 * without asking for it, bail out.
2563 if ((flags & MAP_SHARED) != 0) {
2564 if ((fp->f_flag & FWRITE) != 0)
2565 maxprot |= VM_PROT_WRITE;
2566 else if ((prot & VM_PROT_WRITE) != 0)
2569 maxprot |= VM_PROT_WRITE;
2570 cap_maxprot |= VM_PROT_WRITE;
2572 maxprot &= cap_maxprot;
2575 * For regular files and shared memory, POSIX requires that
2576 * the value of foff be a legitimate offset within the data
2577 * object. In particular, negative offsets are invalid.
2578 * Blocking negative offsets and overflows here avoids
2579 * possible wraparound or user-level access into reserved
2580 * ranges of the data object later. In contrast, POSIX does
2581 * not dictate how offsets are used by device drivers, so in
2582 * the case of a device mapping a negative offset is passed
2589 foff < 0 || foff > OFF_MAX - size)
2592 writecounted = FALSE;
2593 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp,
2594 &foff, &object, &writecounted);
2597 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
2598 foff, writecounted, td);
2601 * If this mapping was accounted for in the vnode's
2602 * writecount, then undo that now.
2605 vm_pager_release_writecount(object, 0, size);
2606 vm_object_deallocate(object);
2609 /* Inform hwpmc(4) if an executable is being mapped. */
2610 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) {
2611 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) {
2613 pkm.pm_address = (uintptr_t) *addr;
2614 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_MMAP, (void *) &pkm);
2622 vn_fsid(struct vnode *vp, struct vattr *va)
2626 f = &vp->v_mount->mnt_stat.f_fsid;
2627 va->va_fsid = (uint32_t)f->val[1];
2628 va->va_fsid <<= sizeof(f->val[1]) * NBBY;
2629 va->va_fsid += (uint32_t)f->val[0];
2633 vn_fsync_buf(struct vnode *vp, int waitfor)
2635 struct buf *bp, *nbp;
2638 int error, maxretry;
2641 maxretry = 10000; /* large, arbitrarily chosen */
2643 if (vp->v_type == VCHR) {
2645 mp = vp->v_rdev->si_mountpt;
2652 * MARK/SCAN initialization to avoid infinite loops.
2654 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) {
2655 bp->b_vflags &= ~BV_SCANNED;
2660 * Flush all dirty buffers associated with a vnode.
2663 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
2664 if ((bp->b_vflags & BV_SCANNED) != 0)
2666 bp->b_vflags |= BV_SCANNED;
2667 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) {
2668 if (waitfor != MNT_WAIT)
2671 LK_EXCLUSIVE | LK_INTERLOCK | LK_SLEEPFAIL,
2672 BO_LOCKPTR(bo)) != 0) {
2679 KASSERT(bp->b_bufobj == bo,
2680 ("bp %p wrong b_bufobj %p should be %p",
2681 bp, bp->b_bufobj, bo));
2682 if ((bp->b_flags & B_DELWRI) == 0)
2683 panic("fsync: not dirty");
2684 if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) {
2690 if (maxretry < 1000)
2691 pause("dirty", hz < 1000 ? 1 : hz / 1000);
2697 * If synchronous the caller expects us to completely resolve all
2698 * dirty buffers in the system. Wait for in-progress I/O to
2699 * complete (which could include background bitmap writes), then
2700 * retry if dirty blocks still exist.
2702 if (waitfor == MNT_WAIT) {
2703 bufobj_wwait(bo, 0, 0);
2704 if (bo->bo_dirty.bv_cnt > 0) {
2706 * If we are unable to write any of these buffers
2707 * then we fail now rather than trying endlessly
2708 * to write them out.
2710 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs)
2711 if ((error = bp->b_error) != 0)
2713 if ((mp != NULL && mp->mnt_secondary_writes > 0) ||
2714 (error == 0 && --maxretry >= 0))
2722 vn_printf(vp, "fsync: giving up on dirty (error = %d) ", error);
2728 * Copies a byte range from invp to outvp. Calls VOP_COPY_FILE_RANGE()
2729 * or vn_generic_copy_file_range() after rangelocking the byte ranges,
2730 * to do the actual copy.
2731 * vn_generic_copy_file_range() is factored out, so it can be called
2732 * from a VOP_COPY_FILE_RANGE() call as well, but handles vnodes from
2733 * different file systems.
2736 vn_copy_file_range(struct vnode *invp, off_t *inoffp, struct vnode *outvp,
2737 off_t *outoffp, size_t *lenp, unsigned int flags, struct ucred *incred,
2738 struct ucred *outcred, struct thread *fsize_td)
2742 uint64_t uvalin, uvalout;
2745 *lenp = 0; /* For error returns. */
2748 /* Do some sanity checks on the arguments. */
2753 if (invp->v_type == VDIR || outvp->v_type == VDIR)
2755 else if (*inoffp < 0 || uvalin > INT64_MAX || uvalin <
2756 (uint64_t)*inoffp || *outoffp < 0 || uvalout > INT64_MAX ||
2757 uvalout < (uint64_t)*outoffp || invp->v_type != VREG ||
2758 outvp->v_type != VREG)
2764 * If the two vnode are for the same file system, call
2765 * VOP_COPY_FILE_RANGE(), otherwise call vn_generic_copy_file_range()
2766 * which can handle copies across multiple file systems.
2769 if (invp->v_mount == outvp->v_mount)
2770 error = VOP_COPY_FILE_RANGE(invp, inoffp, outvp, outoffp,
2771 lenp, flags, incred, outcred, fsize_td);
2773 error = vn_generic_copy_file_range(invp, inoffp, outvp,
2774 outoffp, lenp, flags, incred, outcred, fsize_td);
2780 * Test len bytes of data starting at dat for all bytes == 0.
2781 * Return true if all bytes are zero, false otherwise.
2782 * Expects dat to be well aligned.
2785 mem_iszero(void *dat, int len)
2791 for (p = dat; len > 0; len -= sizeof(*p), p++) {
2792 if (len >= sizeof(*p)) {
2796 cp = (const char *)p;
2797 for (i = 0; i < len; i++, cp++)
2806 * Look for a hole in the output file and, if found, adjust *outoffp
2807 * and *xferp to skip past the hole.
2808 * *xferp is the entire hole length to be written and xfer2 is how many bytes
2809 * to be written as 0's upon return.
2812 vn_skip_hole(struct vnode *outvp, off_t xfer2, off_t *outoffp, off_t *xferp,
2813 off_t *dataoffp, off_t *holeoffp, struct ucred *cred)
2818 if (*holeoffp == 0 || *holeoffp <= *outoffp) {
2819 *dataoffp = *outoffp;
2820 error = VOP_IOCTL(outvp, FIOSEEKDATA, dataoffp, 0, cred,
2823 *holeoffp = *dataoffp;
2824 error = VOP_IOCTL(outvp, FIOSEEKHOLE, holeoffp, 0, cred,
2827 if (error != 0 || *holeoffp == *dataoffp) {
2829 * Since outvp is unlocked, it may be possible for
2830 * another thread to do a truncate(), lseek(), write()
2831 * creating a hole at startoff between the above
2832 * VOP_IOCTL() calls, if the other thread does not do
2834 * If that happens, *holeoffp == *dataoffp and finding
2835 * the hole has failed, so disable vn_skip_hole().
2837 *holeoffp = -1; /* Disable use of vn_skip_hole(). */
2840 KASSERT(*dataoffp >= *outoffp,
2841 ("vn_skip_hole: dataoff=%jd < outoff=%jd",
2842 (intmax_t)*dataoffp, (intmax_t)*outoffp));
2843 KASSERT(*holeoffp > *dataoffp,
2844 ("vn_skip_hole: holeoff=%jd <= dataoff=%jd",
2845 (intmax_t)*holeoffp, (intmax_t)*dataoffp));
2849 * If there is a hole before the data starts, advance *outoffp and
2850 * *xferp past the hole.
2852 if (*dataoffp > *outoffp) {
2853 delta = *dataoffp - *outoffp;
2854 if (delta >= *xferp) {
2855 /* Entire *xferp is a hole. */
2862 xfer2 = MIN(xfer2, *xferp);
2866 * If a hole starts before the end of this xfer2, reduce this xfer2 so
2867 * that the write ends at the start of the hole.
2868 * *holeoffp should always be greater than *outoffp, but for the
2869 * non-INVARIANTS case, check this to make sure xfer2 remains a sane
2872 if (*holeoffp > *outoffp && *holeoffp < *outoffp + xfer2)
2873 xfer2 = *holeoffp - *outoffp;
2878 * Write an xfer sized chunk to outvp in blksize blocks from dat.
2879 * dat is a maximum of blksize in length and can be written repeatedly in
2881 * If growfile == true, just grow the file via vn_truncate_locked() instead
2882 * of doing actual writes.
2883 * If checkhole == true, a hole is being punched, so skip over any hole
2884 * already in the output file.
2887 vn_write_outvp(struct vnode *outvp, char *dat, off_t outoff, off_t xfer,
2888 u_long blksize, bool growfile, bool checkhole, struct ucred *cred)
2891 off_t dataoff, holeoff, xfer2;
2895 * Loop around doing writes of blksize until write has been completed.
2896 * Lock/unlock on each loop iteration so that a bwillwrite() can be
2897 * done for each iteration, since the xfer argument can be very
2898 * large if there is a large hole to punch in the output file.
2903 xfer2 = MIN(xfer, blksize);
2906 * Punching a hole. Skip writing if there is
2907 * already a hole in the output file.
2909 xfer2 = vn_skip_hole(outvp, xfer2, &outoff, &xfer,
2910 &dataoff, &holeoff, cred);
2915 KASSERT(xfer2 > 0, ("vn_write_outvp: xfer2=%jd",
2920 error = vn_start_write(outvp, &mp, V_WAIT);
2922 if (MNT_SHARED_WRITES(mp))
2925 lckf = LK_EXCLUSIVE;
2926 error = vn_lock(outvp, lckf);
2930 error = vn_truncate_locked(outvp, outoff + xfer,
2933 error = vn_rdwr(UIO_WRITE, outvp, dat, xfer2,
2934 outoff, UIO_SYSSPACE, IO_NODELOCKED,
2935 curthread->td_ucred, cred, NULL, curthread);
2942 vn_finished_write(mp);
2943 } while (!growfile && xfer > 0 && error == 0);
2948 * Copy a byte range of one file to another. This function can handle the
2949 * case where invp and outvp are on different file systems.
2950 * It can also be called by a VOP_COPY_FILE_RANGE() to do the work, if there
2951 * is no better file system specific way to do it.
2954 vn_generic_copy_file_range(struct vnode *invp, off_t *inoffp,
2955 struct vnode *outvp, off_t *outoffp, size_t *lenp, unsigned int flags,
2956 struct ucred *incred, struct ucred *outcred, struct thread *fsize_td)
2961 off_t startoff, endoff, xfer, xfer2;
2964 bool cantseek, readzeros, eof, lastblock;
2966 size_t copylen, len, savlen;
2968 long holein, holeout;
2970 holein = holeout = 0;
2971 savlen = len = *lenp;
2975 error = vn_lock(invp, LK_SHARED);
2978 if (VOP_PATHCONF(invp, _PC_MIN_HOLE_SIZE, &holein) != 0)
2983 error = vn_start_write(outvp, &mp, V_WAIT);
2985 error = vn_lock(outvp, LK_EXCLUSIVE);
2988 * If fsize_td != NULL, do a vn_rlimit_fsize() call,
2989 * now that outvp is locked.
2991 if (fsize_td != NULL) {
2992 io.uio_offset = *outoffp;
2994 error = vn_rlimit_fsize(outvp, &io, fsize_td);
2998 if (VOP_PATHCONF(outvp, _PC_MIN_HOLE_SIZE, &holeout) != 0)
3001 * Holes that are past EOF do not need to be written as a block
3002 * of zero bytes. So, truncate the output file as far as
3003 * possible and then use va.va_size to decide if writing 0
3004 * bytes is necessary in the loop below.
3007 error = VOP_GETATTR(outvp, &va, outcred);
3008 if (error == 0 && va.va_size > *outoffp && va.va_size <=
3011 error = mac_vnode_check_write(curthread->td_ucred,
3015 error = vn_truncate_locked(outvp, *outoffp,
3018 va.va_size = *outoffp;
3023 vn_finished_write(mp);
3028 * Set the blksize to the larger of the hole sizes for invp and outvp.
3029 * If hole sizes aren't available, set the blksize to the larger
3030 * f_iosize of invp and outvp.
3031 * This code expects the hole sizes and f_iosizes to be powers of 2.
3032 * This value is clipped at 4Kbytes and 1Mbyte.
3034 blksize = MAX(holein, holeout);
3036 blksize = MAX(invp->v_mount->mnt_stat.f_iosize,
3037 outvp->v_mount->mnt_stat.f_iosize);
3040 else if (blksize > 1024 * 1024)
3041 blksize = 1024 * 1024;
3042 dat = malloc(blksize, M_TEMP, M_WAITOK);
3045 * If VOP_IOCTL(FIOSEEKHOLE) works for invp, use it and FIOSEEKDATA
3046 * to find holes. Otherwise, just scan the read block for all 0s
3047 * in the inner loop where the data copying is done.
3048 * Note that some file systems such as NFSv3, NFSv4.0 and NFSv4.1 may
3049 * support holes on the server, but do not support FIOSEEKHOLE.
3052 while (len > 0 && error == 0 && !eof) {
3053 endoff = 0; /* To shut up compilers. */
3059 * Find the next data area. If there is just a hole to EOF,
3060 * FIOSEEKDATA should fail and then we drop down into the
3061 * inner loop and create the hole on the outvp file.
3062 * (I do not know if any file system will report a hole to
3063 * EOF via FIOSEEKHOLE, but I am pretty sure FIOSEEKDATA
3064 * will fail for those file systems.)
3066 * For input files that don't support FIOSEEKDATA/FIOSEEKHOLE,
3067 * the code just falls through to the inner copy loop.
3071 error = VOP_IOCTL(invp, FIOSEEKDATA, &startoff, 0,
3075 error = VOP_IOCTL(invp, FIOSEEKHOLE, &endoff, 0,
3078 * Since invp is unlocked, it may be possible for
3079 * another thread to do a truncate(), lseek(), write()
3080 * creating a hole at startoff between the above
3081 * VOP_IOCTL() calls, if the other thread does not do
3083 * If that happens, startoff == endoff and finding
3084 * the hole has failed, so set an error.
3086 if (error == 0 && startoff == endoff)
3087 error = EINVAL; /* Any error. Reset to 0. */
3090 if (startoff > *inoffp) {
3091 /* Found hole before data block. */
3092 xfer = MIN(startoff - *inoffp, len);
3093 if (*outoffp < va.va_size) {
3094 /* Must write 0s to punch hole. */
3095 xfer2 = MIN(va.va_size - *outoffp,
3097 memset(dat, 0, MIN(xfer2, blksize));
3098 error = vn_write_outvp(outvp, dat,
3099 *outoffp, xfer2, blksize, false,
3100 holeout > 0, outcred);
3103 if (error == 0 && *outoffp + xfer >
3104 va.va_size && xfer == len)
3105 /* Grow last block. */
3106 error = vn_write_outvp(outvp, dat,
3107 *outoffp, xfer, blksize, true,
3115 copylen = MIN(len, endoff - startoff);
3127 * Set first xfer to end at a block boundary, so that
3128 * holes are more likely detected in the loop below via
3129 * the for all bytes 0 method.
3131 xfer -= (*inoffp % blksize);
3133 /* Loop copying the data block. */
3134 while (copylen > 0 && error == 0 && !eof) {
3137 error = vn_lock(invp, LK_SHARED);
3140 error = vn_rdwr(UIO_READ, invp, dat, xfer,
3141 startoff, UIO_SYSSPACE, IO_NODELOCKED,
3142 curthread->td_ucred, incred, &aresid,
3146 if (error == 0 && aresid > 0) {
3147 /* Stop the copy at EOF on the input file. */
3154 * Skip the write for holes past the initial EOF
3155 * of the output file, unless this is the last
3156 * write of the output file at EOF.
3158 readzeros = cantseek ? mem_iszero(dat, xfer) :
3162 if (!cantseek || *outoffp < va.va_size ||
3163 lastblock || !readzeros)
3164 error = vn_write_outvp(outvp, dat,
3165 *outoffp, xfer, blksize,
3166 readzeros && lastblock &&
3167 *outoffp >= va.va_size, false,
3181 *lenp = savlen - len;
3187 vn_fallocate(struct file *fp, off_t offset, off_t len, struct thread *td)
3191 off_t olen, ooffset;
3194 int audited_vnode1 = 0;
3198 if (vp->v_type != VREG)
3201 /* Allocating blocks may take a long time, so iterate. */
3208 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
3211 error = vn_lock(vp, LK_EXCLUSIVE);
3213 vn_finished_write(mp);
3217 if (!audited_vnode1) {
3218 AUDIT_ARG_VNODE1(vp);
3223 error = mac_vnode_check_write(td->td_ucred, fp->f_cred, vp);
3226 error = VOP_ALLOCATE(vp, &offset, &len);
3228 vn_finished_write(mp);
3230 if (olen + ooffset != offset + len) {
3231 panic("offset + len changed from %jx/%jx to %jx/%jx",
3232 ooffset, olen, offset, len);
3234 if (error != 0 || len == 0)
3236 KASSERT(olen > len, ("Iteration did not make progress?"));