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>
83 #include <security/audit/audit.h>
84 #include <security/mac/mac_framework.h>
87 #include <vm/vm_extern.h>
89 #include <vm/vm_map.h>
90 #include <vm/vm_object.h>
91 #include <vm/vm_page.h>
92 #include <vm/vm_pager.h>
95 #include <sys/pmckern.h>
98 static fo_rdwr_t vn_read;
99 static fo_rdwr_t vn_write;
100 static fo_rdwr_t vn_io_fault;
101 static fo_truncate_t vn_truncate;
102 static fo_ioctl_t vn_ioctl;
103 static fo_poll_t vn_poll;
104 static fo_kqfilter_t vn_kqfilter;
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 const u_int io_hold_cnt = 16;
129 static int vn_io_fault_enable = 1;
130 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RWTUN,
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_RWTUN,
134 &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting");
135 static int vn_io_pgcache_read_enable = 1;
136 SYSCTL_INT(_debug, OID_AUTO, vn_io_pgcache_read_enable, CTLFLAG_RWTUN,
137 &vn_io_pgcache_read_enable, 0,
138 "Enable copying from page cache for reads, avoiding fs");
139 static u_long vn_io_faults_cnt;
140 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD,
141 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers");
143 static int vfs_allow_read_dir = 0;
144 SYSCTL_INT(_security_bsd, OID_AUTO, allow_read_dir, CTLFLAG_RW,
145 &vfs_allow_read_dir, 0,
146 "Enable read(2) of directory by root for filesystems that support it");
149 * Returns true if vn_io_fault mode of handling the i/o request should
153 do_vn_io_fault(struct vnode *vp, struct uio *uio)
157 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG &&
158 (mp = vp->v_mount) != NULL &&
159 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable);
163 * Structure used to pass arguments to vn_io_fault1(), to do either
164 * file- or vnode-based I/O calls.
166 struct vn_io_fault_args {
174 struct fop_args_tag {
178 struct vop_args_tag {
184 static int vn_io_fault1(struct vnode *vp, struct uio *uio,
185 struct vn_io_fault_args *args, struct thread *td);
188 vn_open(struct nameidata *ndp, int *flagp, int cmode, struct file *fp)
190 struct thread *td = ndp->ni_cnd.cn_thread;
192 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp));
196 open2nameif(int fmode, u_int vn_open_flags)
200 res = ISOPEN | LOCKLEAF;
201 if ((fmode & O_RESOLVE_BENEATH) != 0)
203 if ((vn_open_flags & VN_OPEN_NOAUDIT) == 0)
205 if ((vn_open_flags & VN_OPEN_NOCAPCHECK) != 0)
211 * Common code for vnode open operations via a name lookup.
212 * Lookup the vnode and invoke VOP_CREATE if needed.
213 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
215 * Note that this does NOT free nameidata for the successful case,
216 * due to the NDINIT being done elsewhere.
219 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags,
220 struct ucred *cred, struct file *fp)
224 struct thread *td = ndp->ni_cnd.cn_thread;
226 struct vattr *vap = &vat;
233 if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT |
234 O_EXCL | O_DIRECTORY))
236 else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) {
237 ndp->ni_cnd.cn_nameiop = CREATE;
238 ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags);
240 * Set NOCACHE to avoid flushing the cache when
241 * rolling in many files at once.
243 * Set NC_KEEPPOSENTRY to keep positive entries if they already
244 * exist despite NOCACHE.
246 ndp->ni_cnd.cn_flags |= LOCKPARENT | NOCACHE | NC_KEEPPOSENTRY;
247 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
248 ndp->ni_cnd.cn_flags |= FOLLOW;
249 if ((vn_open_flags & VN_OPEN_INVFS) == 0)
251 if ((error = namei(ndp)) != 0)
253 if (ndp->ni_vp == NULL) {
256 vap->va_mode = cmode;
258 vap->va_vaflags |= VA_EXCLUSIVE;
259 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) {
260 NDFREE(ndp, NDF_ONLY_PNBUF);
262 if ((error = vn_start_write(NULL, &mp,
263 V_XSLEEP | PCATCH)) != 0)
268 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0)
269 ndp->ni_cnd.cn_flags |= MAKEENTRY;
271 error = mac_vnode_check_create(cred, ndp->ni_dvp,
275 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
278 if (error == 0 && (fmode & O_EXCL) != 0 &&
279 (fmode & (O_EXLOCK | O_SHLOCK)) != 0) {
281 vp->v_iflag |= VI_FOPENING;
285 VOP_VPUT_PAIR(ndp->ni_dvp, error == 0 ? &vp : NULL,
287 vn_finished_write(mp);
289 NDFREE(ndp, NDF_ONLY_PNBUF);
290 if (error == ERELOOKUP) {
298 if (ndp->ni_dvp == ndp->ni_vp)
304 if (fmode & O_EXCL) {
308 if (vp->v_type == VDIR) {
315 ndp->ni_cnd.cn_nameiop = LOOKUP;
316 ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags);
317 ndp->ni_cnd.cn_flags |= (fmode & O_NOFOLLOW) != 0 ? NOFOLLOW :
319 if ((fmode & FWRITE) == 0)
320 ndp->ni_cnd.cn_flags |= LOCKSHARED;
321 if ((error = namei(ndp)) != 0)
325 error = vn_open_vnode(vp, fmode, cred, td, fp);
328 vp->v_iflag &= ~VI_FOPENING;
337 NDFREE(ndp, NDF_ONLY_PNBUF);
345 vn_open_vnode_advlock(struct vnode *vp, int fmode, struct file *fp)
348 int error, lock_flags, type;
350 ASSERT_VOP_LOCKED(vp, "vn_open_vnode_advlock");
351 if ((fmode & (O_EXLOCK | O_SHLOCK)) == 0)
353 KASSERT(fp != NULL, ("open with flock requires fp"));
354 if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE)
357 lock_flags = VOP_ISLOCKED(vp);
360 lf.l_whence = SEEK_SET;
363 lf.l_type = (fmode & O_EXLOCK) != 0 ? F_WRLCK : F_RDLCK;
365 if ((fmode & FNONBLOCK) == 0)
367 if ((fmode & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
369 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type);
371 fp->f_flag |= FHASLOCK;
373 vn_lock(vp, lock_flags | LK_RETRY);
378 * Common code for vnode open operations once a vnode is located.
379 * Check permissions, and call the VOP_OPEN routine.
382 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred,
383 struct thread *td, struct file *fp)
388 if (vp->v_type == VLNK) {
389 if ((fmode & O_PATH) == 0 || (fmode & FEXEC) != 0)
392 if (vp->v_type == VSOCK)
394 if (vp->v_type != VDIR && fmode & O_DIRECTORY)
398 if ((fmode & O_PATH) == 0) {
399 if ((fmode & (FWRITE | O_TRUNC)) != 0) {
400 if (vp->v_type == VDIR)
404 if ((fmode & FREAD) != 0)
406 if ((fmode & O_APPEND) && (fmode & FWRITE))
409 if ((fmode & O_CREAT) != 0)
413 if ((fmode & FEXEC) != 0)
416 if ((fmode & O_VERIFY) != 0)
418 error = mac_vnode_check_open(cred, vp, accmode);
422 accmode &= ~(VCREAT | VVERIFY);
424 if ((fmode & O_CREAT) == 0 && accmode != 0) {
425 error = VOP_ACCESS(vp, accmode, cred, td);
429 if ((fmode & O_PATH) != 0) {
430 error = VOP_ACCESS(vp, VREAD, cred, td);
432 fp->f_flag |= FKQALLOWED;
436 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
437 vn_lock(vp, LK_UPGRADE | LK_RETRY);
438 error = VOP_OPEN(vp, fmode, cred, td, fp);
442 error = vn_open_vnode_advlock(vp, fmode, fp);
443 if (error == 0 && (fmode & FWRITE) != 0) {
444 error = VOP_ADD_WRITECOUNT(vp, 1);
446 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
447 __func__, vp, vp->v_writecount);
452 * Error from advlock or VOP_ADD_WRITECOUNT() still requires
453 * calling VOP_CLOSE() to pair with earlier VOP_OPEN().
454 * Arrange for that by having fdrop() to use vn_closefile().
457 fp->f_flag |= FOPENFAILED;
459 if (fp->f_ops == &badfileops) {
460 fp->f_type = DTYPE_VNODE;
466 ASSERT_VOP_LOCKED(vp, "vn_open_vnode");
472 * Check for write permissions on the specified vnode.
473 * Prototype text segments cannot be written.
477 vn_writechk(struct vnode *vp)
480 ASSERT_VOP_LOCKED(vp, "vn_writechk");
482 * If there's shared text associated with
483 * the vnode, try to free it up once. If
484 * we fail, we can't allow writing.
496 vn_close1(struct vnode *vp, int flags, struct ucred *file_cred,
497 struct thread *td, bool keep_ref)
500 int error, lock_flags;
502 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 &&
503 MNT_EXTENDED_SHARED(vp->v_mount))
504 lock_flags = LK_SHARED;
506 lock_flags = LK_EXCLUSIVE;
508 vn_start_write(vp, &mp, V_WAIT);
509 vn_lock(vp, lock_flags | LK_RETRY);
510 AUDIT_ARG_VNODE1(vp);
511 if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) {
512 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
513 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
514 __func__, vp, vp->v_writecount);
516 error = VOP_CLOSE(vp, flags, file_cred, td);
521 vn_finished_write(mp);
526 vn_close(struct vnode *vp, int flags, struct ucred *file_cred,
530 return (vn_close1(vp, flags, file_cred, td, false));
534 * Heuristic to detect sequential operation.
537 sequential_heuristic(struct uio *uio, struct file *fp)
541 ASSERT_VOP_LOCKED(fp->f_vnode, __func__);
544 if (fp->f_flag & FRDAHEAD)
545 return (fp->f_seqcount[rw] << IO_SEQSHIFT);
548 * Offset 0 is handled specially. open() sets f_seqcount to 1 so
549 * that the first I/O is normally considered to be slightly
550 * sequential. Seeking to offset 0 doesn't change sequentiality
551 * unless previous seeks have reduced f_seqcount to 0, in which
552 * case offset 0 is not special.
554 if ((uio->uio_offset == 0 && fp->f_seqcount[rw] > 0) ||
555 uio->uio_offset == fp->f_nextoff[rw]) {
557 * f_seqcount is in units of fixed-size blocks so that it
558 * depends mainly on the amount of sequential I/O and not
559 * much on the number of sequential I/O's. The fixed size
560 * of 16384 is hard-coded here since it is (not quite) just
561 * a magic size that works well here. This size is more
562 * closely related to the best I/O size for real disks than
563 * to any block size used by software.
565 if (uio->uio_resid >= IO_SEQMAX * 16384)
566 fp->f_seqcount[rw] = IO_SEQMAX;
568 fp->f_seqcount[rw] += howmany(uio->uio_resid, 16384);
569 if (fp->f_seqcount[rw] > IO_SEQMAX)
570 fp->f_seqcount[rw] = IO_SEQMAX;
572 return (fp->f_seqcount[rw] << IO_SEQSHIFT);
575 /* Not sequential. Quickly draw-down sequentiality. */
576 if (fp->f_seqcount[rw] > 1)
577 fp->f_seqcount[rw] = 1;
579 fp->f_seqcount[rw] = 0;
584 * Package up an I/O request on a vnode into a uio and do it.
587 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset,
588 enum uio_seg segflg, int ioflg, struct ucred *active_cred,
589 struct ucred *file_cred, ssize_t *aresid, struct thread *td)
596 struct vn_io_fault_args args;
597 int error, lock_flags;
599 if (offset < 0 && vp->v_type != VCHR)
601 auio.uio_iov = &aiov;
603 aiov.iov_base = base;
605 auio.uio_resid = len;
606 auio.uio_offset = offset;
607 auio.uio_segflg = segflg;
612 if ((ioflg & IO_NODELOCKED) == 0) {
613 if ((ioflg & IO_RANGELOCKED) == 0) {
614 if (rw == UIO_READ) {
615 rl_cookie = vn_rangelock_rlock(vp, offset,
617 } else if ((ioflg & IO_APPEND) != 0) {
618 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
620 rl_cookie = vn_rangelock_wlock(vp, offset,
626 if (rw == UIO_WRITE) {
627 if (vp->v_type != VCHR &&
628 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH))
631 if (MNT_SHARED_WRITES(mp) ||
632 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount)))
633 lock_flags = LK_SHARED;
635 lock_flags = LK_EXCLUSIVE;
637 lock_flags = LK_SHARED;
638 vn_lock(vp, lock_flags | LK_RETRY);
642 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
644 if ((ioflg & IO_NOMACCHECK) == 0) {
646 error = mac_vnode_check_read(active_cred, file_cred,
649 error = mac_vnode_check_write(active_cred, file_cred,
654 if (file_cred != NULL)
658 if (do_vn_io_fault(vp, &auio)) {
659 args.kind = VN_IO_FAULT_VOP;
662 args.args.vop_args.vp = vp;
663 error = vn_io_fault1(vp, &auio, &args, td);
664 } else if (rw == UIO_READ) {
665 error = VOP_READ(vp, &auio, ioflg, cred);
666 } else /* if (rw == UIO_WRITE) */ {
667 error = VOP_WRITE(vp, &auio, ioflg, cred);
671 *aresid = auio.uio_resid;
673 if (auio.uio_resid && error == 0)
675 if ((ioflg & IO_NODELOCKED) == 0) {
678 vn_finished_write(mp);
681 if (rl_cookie != NULL)
682 vn_rangelock_unlock(vp, rl_cookie);
687 * Package up an I/O request on a vnode into a uio and do it. The I/O
688 * request is split up into smaller chunks and we try to avoid saturating
689 * the buffer cache while potentially holding a vnode locked, so we
690 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield()
691 * to give other processes a chance to lock the vnode (either other processes
692 * core'ing the same binary, or unrelated processes scanning the directory).
695 vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, void *base, size_t len,
696 off_t offset, enum uio_seg segflg, int ioflg, struct ucred *active_cred,
697 struct ucred *file_cred, size_t *aresid, struct thread *td)
706 * Force `offset' to a multiple of MAXBSIZE except possibly
707 * for the first chunk, so that filesystems only need to
708 * write full blocks except possibly for the first and last
711 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE;
715 if (rw != UIO_READ && vp->v_type == VREG)
718 error = vn_rdwr(rw, vp, base, chunk, offset, segflg,
719 ioflg, active_cred, file_cred, &iaresid, td);
720 len -= chunk; /* aresid calc already includes length */
724 base = (char *)base + chunk;
725 kern_yield(PRI_USER);
728 *aresid = len + iaresid;
732 #if OFF_MAX <= LONG_MAX
734 foffset_lock(struct file *fp, int flags)
736 volatile short *flagsp;
740 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
742 if ((flags & FOF_NOLOCK) != 0)
743 return (atomic_load_long(&fp->f_offset));
746 * According to McKusick the vn lock was protecting f_offset here.
747 * It is now protected by the FOFFSET_LOCKED flag.
749 flagsp = &fp->f_vnread_flags;
750 if (atomic_cmpset_acq_16(flagsp, 0, FOFFSET_LOCKED))
751 return (atomic_load_long(&fp->f_offset));
753 sleepq_lock(&fp->f_vnread_flags);
754 state = atomic_load_16(flagsp);
756 if ((state & FOFFSET_LOCKED) == 0) {
757 if (!atomic_fcmpset_acq_16(flagsp, &state,
762 if ((state & FOFFSET_LOCK_WAITING) == 0) {
763 if (!atomic_fcmpset_acq_16(flagsp, &state,
764 state | FOFFSET_LOCK_WAITING))
768 sleepq_add(&fp->f_vnread_flags, NULL, "vofflock", 0, 0);
769 sleepq_wait(&fp->f_vnread_flags, PUSER -1);
771 sleepq_lock(&fp->f_vnread_flags);
772 state = atomic_load_16(flagsp);
774 res = atomic_load_long(&fp->f_offset);
775 sleepq_release(&fp->f_vnread_flags);
780 foffset_unlock(struct file *fp, off_t val, int flags)
782 volatile short *flagsp;
785 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
787 if ((flags & FOF_NOUPDATE) == 0)
788 atomic_store_long(&fp->f_offset, val);
789 if ((flags & FOF_NEXTOFF_R) != 0)
790 fp->f_nextoff[UIO_READ] = val;
791 if ((flags & FOF_NEXTOFF_W) != 0)
792 fp->f_nextoff[UIO_WRITE] = val;
794 if ((flags & FOF_NOLOCK) != 0)
797 flagsp = &fp->f_vnread_flags;
798 state = atomic_load_16(flagsp);
799 if ((state & FOFFSET_LOCK_WAITING) == 0 &&
800 atomic_cmpset_rel_16(flagsp, state, 0))
803 sleepq_lock(&fp->f_vnread_flags);
804 MPASS((fp->f_vnread_flags & FOFFSET_LOCKED) != 0);
805 MPASS((fp->f_vnread_flags & FOFFSET_LOCK_WAITING) != 0);
806 fp->f_vnread_flags = 0;
807 sleepq_broadcast(&fp->f_vnread_flags, SLEEPQ_SLEEP, 0, 0);
808 sleepq_release(&fp->f_vnread_flags);
812 foffset_lock(struct file *fp, int flags)
817 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
819 mtxp = mtx_pool_find(mtxpool_sleep, fp);
821 if ((flags & FOF_NOLOCK) == 0) {
822 while (fp->f_vnread_flags & FOFFSET_LOCKED) {
823 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING;
824 msleep(&fp->f_vnread_flags, mtxp, PUSER -1,
827 fp->f_vnread_flags |= FOFFSET_LOCKED;
835 foffset_unlock(struct file *fp, off_t val, int flags)
839 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
841 mtxp = mtx_pool_find(mtxpool_sleep, fp);
843 if ((flags & FOF_NOUPDATE) == 0)
845 if ((flags & FOF_NEXTOFF_R) != 0)
846 fp->f_nextoff[UIO_READ] = val;
847 if ((flags & FOF_NEXTOFF_W) != 0)
848 fp->f_nextoff[UIO_WRITE] = val;
849 if ((flags & FOF_NOLOCK) == 0) {
850 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0,
851 ("Lost FOFFSET_LOCKED"));
852 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING)
853 wakeup(&fp->f_vnread_flags);
854 fp->f_vnread_flags = 0;
861 foffset_lock_uio(struct file *fp, struct uio *uio, int flags)
864 if ((flags & FOF_OFFSET) == 0)
865 uio->uio_offset = foffset_lock(fp, flags);
869 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags)
872 if ((flags & FOF_OFFSET) == 0)
873 foffset_unlock(fp, uio->uio_offset, flags);
877 get_advice(struct file *fp, struct uio *uio)
882 ret = POSIX_FADV_NORMAL;
883 if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG)
886 mtxp = mtx_pool_find(mtxpool_sleep, fp);
888 if (fp->f_advice != NULL &&
889 uio->uio_offset >= fp->f_advice->fa_start &&
890 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end)
891 ret = fp->f_advice->fa_advice;
897 vn_read_from_obj(struct vnode *vp, struct uio *uio)
900 vm_page_t ma[io_hold_cnt + 2];
905 MPASS(uio->uio_resid <= ptoa(io_hold_cnt + 2));
906 obj = atomic_load_ptr(&vp->v_object);
908 return (EJUSTRETURN);
911 * Depends on type stability of vm_objects.
913 vm_object_pip_add(obj, 1);
914 if ((obj->flags & OBJ_DEAD) != 0) {
916 * Note that object might be already reused from the
917 * vnode, and the OBJ_DEAD flag cleared. This is fine,
918 * we recheck for DOOMED vnode state after all pages
919 * are busied, and retract then.
921 * But we check for OBJ_DEAD to ensure that we do not
922 * busy pages while vm_object_terminate_pages()
923 * processes the queue.
929 resid = uio->uio_resid;
930 off = uio->uio_offset;
931 for (i = 0; resid > 0; i++) {
932 MPASS(i < io_hold_cnt + 2);
933 ma[i] = vm_page_grab_unlocked(obj, atop(off),
934 VM_ALLOC_NOCREAT | VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY |
940 * Skip invalid pages. Valid mask can be partial only
941 * at EOF, and we clip later.
943 if (vm_page_none_valid(ma[i])) {
944 vm_page_sunbusy(ma[i]);
957 * Check VIRF_DOOMED after we busied our pages. Since
958 * vgonel() terminates the vnode' vm_object, it cannot
959 * process past pages busied by us.
961 if (VN_IS_DOOMED(vp)) {
966 resid = PAGE_SIZE - (uio->uio_offset & PAGE_MASK) + ptoa(i - 1);
967 if (resid > uio->uio_resid)
968 resid = uio->uio_resid;
971 * Unlocked read of vnp_size is safe because truncation cannot
972 * pass busied page. But we load vnp_size into a local
973 * variable so that possible concurrent extension does not
976 #if defined(__powerpc__) && !defined(__powerpc64__)
977 vsz = obj->un_pager.vnp.vnp_size;
979 vsz = atomic_load_64(&obj->un_pager.vnp.vnp_size);
981 if (uio->uio_offset >= vsz) {
985 if (uio->uio_offset + resid > vsz)
986 resid = vsz - uio->uio_offset;
988 error = vn_io_fault_pgmove(ma, uio->uio_offset & PAGE_MASK, resid, uio);
991 for (j = 0; j < i; j++) {
993 vm_page_reference(ma[j]);
994 vm_page_sunbusy(ma[j]);
997 vm_object_pip_wakeup(obj);
1000 return (uio->uio_resid == 0 ? 0 : EJUSTRETURN);
1004 * File table vnode read routine.
1007 vn_read(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
1015 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
1017 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
1020 if (fp->f_flag & FNONBLOCK)
1021 ioflag |= IO_NDELAY;
1022 if (fp->f_flag & O_DIRECT)
1023 ioflag |= IO_DIRECT;
1026 * Try to read from page cache. VIRF_DOOMED check is racy but
1027 * allows us to avoid unneeded work outright.
1029 if (vn_io_pgcache_read_enable && !mac_vnode_check_read_enabled() &&
1030 (vn_irflag_read(vp) & (VIRF_DOOMED | VIRF_PGREAD)) == VIRF_PGREAD) {
1031 error = VOP_READ_PGCACHE(vp, uio, ioflag, fp->f_cred);
1033 fp->f_nextoff[UIO_READ] = uio->uio_offset;
1036 if (error != EJUSTRETURN)
1040 advice = get_advice(fp, uio);
1041 vn_lock(vp, LK_SHARED | LK_RETRY);
1044 case POSIX_FADV_NORMAL:
1045 case POSIX_FADV_SEQUENTIAL:
1046 case POSIX_FADV_NOREUSE:
1047 ioflag |= sequential_heuristic(uio, fp);
1049 case POSIX_FADV_RANDOM:
1050 /* Disable read-ahead for random I/O. */
1053 orig_offset = uio->uio_offset;
1056 error = mac_vnode_check_read(active_cred, fp->f_cred, vp);
1059 error = VOP_READ(vp, uio, ioflag, fp->f_cred);
1060 fp->f_nextoff[UIO_READ] = uio->uio_offset;
1062 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
1063 orig_offset != uio->uio_offset)
1065 * Use POSIX_FADV_DONTNEED to flush pages and buffers
1066 * for the backing file after a POSIX_FADV_NOREUSE
1069 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
1070 POSIX_FADV_DONTNEED);
1075 * File table vnode write routine.
1078 vn_write(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
1084 int error, ioflag, lock_flags;
1087 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
1089 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
1091 if (vp->v_type == VREG)
1094 if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
1095 ioflag |= IO_APPEND;
1096 if (fp->f_flag & FNONBLOCK)
1097 ioflag |= IO_NDELAY;
1098 if (fp->f_flag & O_DIRECT)
1099 ioflag |= IO_DIRECT;
1100 if ((fp->f_flag & O_FSYNC) ||
1101 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
1104 * For O_DSYNC we set both IO_SYNC and IO_DATASYNC, so that VOP_WRITE()
1105 * implementations that don't understand IO_DATASYNC fall back to full
1108 if (fp->f_flag & O_DSYNC)
1109 ioflag |= IO_SYNC | IO_DATASYNC;
1111 if (vp->v_type != VCHR &&
1112 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
1115 advice = get_advice(fp, uio);
1117 if (MNT_SHARED_WRITES(mp) ||
1118 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) {
1119 lock_flags = LK_SHARED;
1121 lock_flags = LK_EXCLUSIVE;
1124 vn_lock(vp, lock_flags | LK_RETRY);
1126 case POSIX_FADV_NORMAL:
1127 case POSIX_FADV_SEQUENTIAL:
1128 case POSIX_FADV_NOREUSE:
1129 ioflag |= sequential_heuristic(uio, fp);
1131 case POSIX_FADV_RANDOM:
1132 /* XXX: Is this correct? */
1135 orig_offset = uio->uio_offset;
1138 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
1141 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred);
1142 fp->f_nextoff[UIO_WRITE] = uio->uio_offset;
1144 if (vp->v_type != VCHR)
1145 vn_finished_write(mp);
1146 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
1147 orig_offset != uio->uio_offset)
1149 * Use POSIX_FADV_DONTNEED to flush pages and buffers
1150 * for the backing file after a POSIX_FADV_NOREUSE
1153 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
1154 POSIX_FADV_DONTNEED);
1160 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to
1161 * prevent the following deadlock:
1163 * Assume that the thread A reads from the vnode vp1 into userspace
1164 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is
1165 * currently not resident, then system ends up with the call chain
1166 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] ->
1167 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2)
1168 * which establishes lock order vp1->vn_lock, then vp2->vn_lock.
1169 * If, at the same time, thread B reads from vnode vp2 into buffer buf2
1170 * backed by the pages of vnode vp1, and some page in buf2 is not
1171 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock.
1173 * To prevent the lock order reversal and deadlock, vn_io_fault() does
1174 * not allow page faults to happen during VOP_READ() or VOP_WRITE().
1175 * Instead, it first tries to do the whole range i/o with pagefaults
1176 * disabled. If all pages in the i/o buffer are resident and mapped,
1177 * VOP will succeed (ignoring the genuine filesystem errors).
1178 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do
1179 * i/o in chunks, with all pages in the chunk prefaulted and held
1180 * using vm_fault_quick_hold_pages().
1182 * Filesystems using this deadlock avoidance scheme should use the
1183 * array of the held pages from uio, saved in the curthread->td_ma,
1184 * instead of doing uiomove(). A helper function
1185 * vn_io_fault_uiomove() converts uiomove request into
1186 * uiomove_fromphys() over td_ma array.
1188 * Since vnode locks do not cover the whole i/o anymore, rangelocks
1189 * make the current i/o request atomic with respect to other i/os and
1194 * Decode vn_io_fault_args and perform the corresponding i/o.
1197 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio,
1203 save = vm_fault_disable_pagefaults();
1204 switch (args->kind) {
1205 case VN_IO_FAULT_FOP:
1206 error = (args->args.fop_args.doio)(args->args.fop_args.fp,
1207 uio, args->cred, args->flags, td);
1209 case VN_IO_FAULT_VOP:
1210 if (uio->uio_rw == UIO_READ) {
1211 error = VOP_READ(args->args.vop_args.vp, uio,
1212 args->flags, args->cred);
1213 } else if (uio->uio_rw == UIO_WRITE) {
1214 error = VOP_WRITE(args->args.vop_args.vp, uio,
1215 args->flags, args->cred);
1219 panic("vn_io_fault_doio: unknown kind of io %d %d",
1220 args->kind, uio->uio_rw);
1222 vm_fault_enable_pagefaults(save);
1227 vn_io_fault_touch(char *base, const struct uio *uio)
1232 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1))
1238 vn_io_fault_prefault_user(const struct uio *uio)
1241 const struct iovec *iov;
1246 KASSERT(uio->uio_segflg == UIO_USERSPACE,
1247 ("vn_io_fault_prefault userspace"));
1251 resid = uio->uio_resid;
1252 base = iov->iov_base;
1255 error = vn_io_fault_touch(base, uio);
1258 if (len < PAGE_SIZE) {
1260 error = vn_io_fault_touch(base + len - 1, uio);
1265 if (++i >= uio->uio_iovcnt)
1267 iov = uio->uio_iov + i;
1268 base = iov->iov_base;
1280 * Common code for vn_io_fault(), agnostic to the kind of i/o request.
1281 * Uses vn_io_fault_doio() to make the call to an actual i/o function.
1282 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request
1283 * into args and call vn_io_fault1() to handle faults during the user
1284 * mode buffer accesses.
1287 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args,
1290 vm_page_t ma[io_hold_cnt + 2];
1291 struct uio *uio_clone, short_uio;
1292 struct iovec short_iovec[1];
1293 vm_page_t *prev_td_ma;
1295 vm_offset_t addr, end;
1298 int error, cnt, saveheld, prev_td_ma_cnt;
1300 if (vn_io_fault_prefault) {
1301 error = vn_io_fault_prefault_user(uio);
1303 return (error); /* Or ignore ? */
1306 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ;
1309 * The UFS follows IO_UNIT directive and replays back both
1310 * uio_offset and uio_resid if an error is encountered during the
1311 * operation. But, since the iovec may be already advanced,
1312 * uio is still in an inconsistent state.
1314 * Cache a copy of the original uio, which is advanced to the redo
1315 * point using UIO_NOCOPY below.
1317 uio_clone = cloneuio(uio);
1318 resid = uio->uio_resid;
1320 short_uio.uio_segflg = UIO_USERSPACE;
1321 short_uio.uio_rw = uio->uio_rw;
1322 short_uio.uio_td = uio->uio_td;
1324 error = vn_io_fault_doio(args, uio, td);
1325 if (error != EFAULT)
1328 atomic_add_long(&vn_io_faults_cnt, 1);
1329 uio_clone->uio_segflg = UIO_NOCOPY;
1330 uiomove(NULL, resid - uio->uio_resid, uio_clone);
1331 uio_clone->uio_segflg = uio->uio_segflg;
1333 saveheld = curthread_pflags_set(TDP_UIOHELD);
1334 prev_td_ma = td->td_ma;
1335 prev_td_ma_cnt = td->td_ma_cnt;
1337 while (uio_clone->uio_resid != 0) {
1338 len = uio_clone->uio_iov->iov_len;
1340 KASSERT(uio_clone->uio_iovcnt >= 1,
1341 ("iovcnt underflow"));
1342 uio_clone->uio_iov++;
1343 uio_clone->uio_iovcnt--;
1346 if (len > ptoa(io_hold_cnt))
1347 len = ptoa(io_hold_cnt);
1348 addr = (uintptr_t)uio_clone->uio_iov->iov_base;
1349 end = round_page(addr + len);
1354 cnt = atop(end - trunc_page(addr));
1356 * A perfectly misaligned address and length could cause
1357 * both the start and the end of the chunk to use partial
1358 * page. +2 accounts for such a situation.
1360 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map,
1361 addr, len, prot, ma, io_hold_cnt + 2);
1366 short_uio.uio_iov = &short_iovec[0];
1367 short_iovec[0].iov_base = (void *)addr;
1368 short_uio.uio_iovcnt = 1;
1369 short_uio.uio_resid = short_iovec[0].iov_len = len;
1370 short_uio.uio_offset = uio_clone->uio_offset;
1372 td->td_ma_cnt = cnt;
1374 error = vn_io_fault_doio(args, &short_uio, td);
1375 vm_page_unhold_pages(ma, cnt);
1376 adv = len - short_uio.uio_resid;
1378 uio_clone->uio_iov->iov_base =
1379 (char *)uio_clone->uio_iov->iov_base + adv;
1380 uio_clone->uio_iov->iov_len -= adv;
1381 uio_clone->uio_resid -= adv;
1382 uio_clone->uio_offset += adv;
1384 uio->uio_resid -= adv;
1385 uio->uio_offset += adv;
1387 if (error != 0 || adv == 0)
1390 td->td_ma = prev_td_ma;
1391 td->td_ma_cnt = prev_td_ma_cnt;
1392 curthread_pflags_restore(saveheld);
1394 free(uio_clone, M_IOV);
1399 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred,
1400 int flags, struct thread *td)
1405 struct vn_io_fault_args args;
1408 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write;
1412 * The ability to read(2) on a directory has historically been
1413 * allowed for all users, but this can and has been the source of
1414 * at least one security issue in the past. As such, it is now hidden
1415 * away behind a sysctl for those that actually need it to use it, and
1416 * restricted to root when it's turned on to make it relatively safe to
1417 * leave on for longer sessions of need.
1419 if (vp->v_type == VDIR) {
1420 KASSERT(uio->uio_rw == UIO_READ,
1421 ("illegal write attempted on a directory"));
1422 if (!vfs_allow_read_dir)
1424 if ((error = priv_check(td, PRIV_VFS_READ_DIR)) != 0)
1428 foffset_lock_uio(fp, uio, flags);
1429 if (do_vn_io_fault(vp, uio)) {
1430 args.kind = VN_IO_FAULT_FOP;
1431 args.args.fop_args.fp = fp;
1432 args.args.fop_args.doio = doio;
1433 args.cred = active_cred;
1434 args.flags = flags | FOF_OFFSET;
1435 if (uio->uio_rw == UIO_READ) {
1436 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset,
1437 uio->uio_offset + uio->uio_resid);
1438 } else if ((fp->f_flag & O_APPEND) != 0 ||
1439 (flags & FOF_OFFSET) == 0) {
1440 /* For appenders, punt and lock the whole range. */
1441 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1443 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset,
1444 uio->uio_offset + uio->uio_resid);
1446 error = vn_io_fault1(vp, uio, &args, td);
1447 vn_rangelock_unlock(vp, rl_cookie);
1449 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td);
1451 foffset_unlock_uio(fp, uio, flags);
1456 * Helper function to perform the requested uiomove operation using
1457 * the held pages for io->uio_iov[0].iov_base buffer instead of
1458 * copyin/copyout. Access to the pages with uiomove_fromphys()
1459 * instead of iov_base prevents page faults that could occur due to
1460 * pmap_collect() invalidating the mapping created by
1461 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or
1462 * object cleanup revoking the write access from page mappings.
1464 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove()
1465 * instead of plain uiomove().
1468 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio)
1470 struct uio transp_uio;
1471 struct iovec transp_iov[1];
1477 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1478 uio->uio_segflg != UIO_USERSPACE)
1479 return (uiomove(data, xfersize, uio));
1481 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1482 transp_iov[0].iov_base = data;
1483 transp_uio.uio_iov = &transp_iov[0];
1484 transp_uio.uio_iovcnt = 1;
1485 if (xfersize > uio->uio_resid)
1486 xfersize = uio->uio_resid;
1487 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize;
1488 transp_uio.uio_offset = 0;
1489 transp_uio.uio_segflg = UIO_SYSSPACE;
1491 * Since transp_iov points to data, and td_ma page array
1492 * corresponds to original uio->uio_iov, we need to invert the
1493 * direction of the i/o operation as passed to
1494 * uiomove_fromphys().
1496 switch (uio->uio_rw) {
1498 transp_uio.uio_rw = UIO_READ;
1501 transp_uio.uio_rw = UIO_WRITE;
1504 transp_uio.uio_td = uio->uio_td;
1505 error = uiomove_fromphys(td->td_ma,
1506 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK,
1507 xfersize, &transp_uio);
1508 adv = xfersize - transp_uio.uio_resid;
1510 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) -
1511 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT);
1513 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1515 td->td_ma_cnt -= pgadv;
1516 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv;
1517 uio->uio_iov->iov_len -= adv;
1518 uio->uio_resid -= adv;
1519 uio->uio_offset += adv;
1524 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize,
1528 vm_offset_t iov_base;
1532 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1533 uio->uio_segflg != UIO_USERSPACE)
1534 return (uiomove_fromphys(ma, offset, xfersize, uio));
1536 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1537 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize;
1538 iov_base = (vm_offset_t)uio->uio_iov->iov_base;
1539 switch (uio->uio_rw) {
1541 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma,
1545 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK,
1549 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT);
1551 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1553 td->td_ma_cnt -= pgadv;
1554 uio->uio_iov->iov_base = (char *)(iov_base + cnt);
1555 uio->uio_iov->iov_len -= cnt;
1556 uio->uio_resid -= cnt;
1557 uio->uio_offset += cnt;
1562 * File table truncate routine.
1565 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred,
1577 * Lock the whole range for truncation. Otherwise split i/o
1578 * might happen partly before and partly after the truncation.
1580 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1581 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
1584 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1585 AUDIT_ARG_VNODE1(vp);
1586 if (vp->v_type == VDIR) {
1591 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
1595 error = vn_truncate_locked(vp, length, (fp->f_flag & O_FSYNC) != 0,
1599 vn_finished_write(mp);
1601 vn_rangelock_unlock(vp, rl_cookie);
1602 if (error == ERELOOKUP)
1608 * Truncate a file that is already locked.
1611 vn_truncate_locked(struct vnode *vp, off_t length, bool sync,
1617 error = VOP_ADD_WRITECOUNT(vp, 1);
1620 vattr.va_size = length;
1622 vattr.va_vaflags |= VA_SYNC;
1623 error = VOP_SETATTR(vp, &vattr, cred);
1624 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
1630 * File table vnode stat routine.
1633 vn_statfile(struct file *fp, struct stat *sb, struct ucred *active_cred,
1636 struct vnode *vp = fp->f_vnode;
1639 vn_lock(vp, LK_SHARED | LK_RETRY);
1640 error = VOP_STAT(vp, sb, active_cred, fp->f_cred, td);
1647 * File table vnode ioctl routine.
1650 vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
1655 struct fiobmap2_arg *bmarg;
1659 switch (vp->v_type) {
1664 vn_lock(vp, LK_SHARED | LK_RETRY);
1665 error = VOP_GETATTR(vp, &vattr, active_cred);
1668 *(int *)data = vattr.va_size - fp->f_offset;
1671 bmarg = (struct fiobmap2_arg *)data;
1672 vn_lock(vp, LK_SHARED | LK_RETRY);
1674 error = mac_vnode_check_read(active_cred, fp->f_cred,
1678 error = VOP_BMAP(vp, bmarg->bn, NULL,
1679 &bmarg->bn, &bmarg->runp, &bmarg->runb);
1686 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1691 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1699 * File table vnode poll routine.
1702 vn_poll(struct file *fp, int events, struct ucred *active_cred,
1709 #if defined(MAC) || defined(AUDIT)
1710 if (AUDITING_TD(td) || mac_vnode_check_poll_enabled()) {
1711 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1712 AUDIT_ARG_VNODE1(vp);
1713 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp);
1719 error = VOP_POLL(vp, events, fp->f_cred, td);
1724 * Acquire the requested lock and then check for validity. LK_RETRY
1725 * permits vn_lock to return doomed vnodes.
1727 static int __noinline
1728 _vn_lock_fallback(struct vnode *vp, int flags, const char *file, int line,
1732 KASSERT((flags & LK_RETRY) == 0 || error == 0,
1733 ("vn_lock: error %d incompatible with flags %#x", error, flags));
1736 VNASSERT(VN_IS_DOOMED(vp), vp, ("vnode not doomed"));
1738 if ((flags & LK_RETRY) == 0) {
1749 * Nothing to do if we got the lock.
1755 * Interlock was dropped by the call in _vn_lock.
1757 flags &= ~LK_INTERLOCK;
1759 error = VOP_LOCK1(vp, flags, file, line);
1760 } while (error != 0);
1765 _vn_lock(struct vnode *vp, int flags, const char *file, int line)
1769 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
1770 ("vn_lock: no locktype (%d passed)", flags));
1771 VNPASS(vp->v_holdcnt > 0, vp);
1772 error = VOP_LOCK1(vp, flags, file, line);
1773 if (__predict_false(error != 0 || VN_IS_DOOMED(vp)))
1774 return (_vn_lock_fallback(vp, flags, file, line, error));
1779 * File table vnode close routine.
1782 vn_closefile(struct file *fp, struct thread *td)
1790 fp->f_ops = &badfileops;
1791 ref = (fp->f_flag & FHASLOCK) != 0 && fp->f_type == DTYPE_VNODE;
1793 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref);
1795 if (__predict_false(ref)) {
1796 lf.l_whence = SEEK_SET;
1799 lf.l_type = F_UNLCK;
1800 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK);
1807 * Preparing to start a filesystem write operation. If the operation is
1808 * permitted, then we bump the count of operations in progress and
1809 * proceed. If a suspend request is in progress, we wait until the
1810 * suspension is over, and then proceed.
1813 vn_start_write_refed(struct mount *mp, int flags, bool mplocked)
1815 struct mount_pcpu *mpcpu;
1818 if (__predict_true(!mplocked) && (flags & V_XSLEEP) == 0 &&
1819 vfs_op_thread_enter(mp, mpcpu)) {
1820 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0);
1821 vfs_mp_count_add_pcpu(mpcpu, writeopcount, 1);
1822 vfs_op_thread_exit(mp, mpcpu);
1827 mtx_assert(MNT_MTX(mp), MA_OWNED);
1834 * Check on status of suspension.
1836 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 ||
1837 mp->mnt_susp_owner != curthread) {
1838 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ?
1839 (flags & PCATCH) : 0) | (PUSER - 1);
1840 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1841 if (flags & V_NOWAIT) {
1842 error = EWOULDBLOCK;
1845 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags,
1851 if (flags & V_XSLEEP)
1853 mp->mnt_writeopcount++;
1855 if (error != 0 || (flags & V_XSLEEP) != 0)
1862 vn_start_write(struct vnode *vp, struct mount **mpp, int flags)
1867 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1868 ("V_MNTREF requires mp"));
1872 * If a vnode is provided, get and return the mount point that
1873 * to which it will write.
1876 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1878 if (error != EOPNOTSUPP)
1883 if ((mp = *mpp) == NULL)
1887 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1889 * As long as a vnode is not provided we need to acquire a
1890 * refcount for the provided mountpoint too, in order to
1891 * emulate a vfs_ref().
1893 if (vp == NULL && (flags & V_MNTREF) == 0)
1896 return (vn_start_write_refed(mp, flags, false));
1900 * Secondary suspension. Used by operations such as vop_inactive
1901 * routines that are needed by the higher level functions. These
1902 * are allowed to proceed until all the higher level functions have
1903 * completed (indicated by mnt_writeopcount dropping to zero). At that
1904 * time, these operations are halted until the suspension is over.
1907 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags)
1912 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1913 ("V_MNTREF requires mp"));
1917 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1919 if (error != EOPNOTSUPP)
1925 * If we are not suspended or have not yet reached suspended
1926 * mode, then let the operation proceed.
1928 if ((mp = *mpp) == NULL)
1932 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1934 * As long as a vnode is not provided we need to acquire a
1935 * refcount for the provided mountpoint too, in order to
1936 * emulate a vfs_ref().
1939 if (vp == NULL && (flags & V_MNTREF) == 0)
1941 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) {
1942 mp->mnt_secondary_writes++;
1943 mp->mnt_secondary_accwrites++;
1947 if (flags & V_NOWAIT) {
1950 return (EWOULDBLOCK);
1953 * Wait for the suspension to finish.
1955 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP |
1956 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0),
1965 * Filesystem write operation has completed. If we are suspending and this
1966 * operation is the last one, notify the suspender that the suspension is
1970 vn_finished_write(struct mount *mp)
1972 struct mount_pcpu *mpcpu;
1978 if (vfs_op_thread_enter(mp, mpcpu)) {
1979 vfs_mp_count_sub_pcpu(mpcpu, writeopcount, 1);
1980 vfs_mp_count_sub_pcpu(mpcpu, ref, 1);
1981 vfs_op_thread_exit(mp, mpcpu);
1986 vfs_assert_mount_counters(mp);
1988 c = --mp->mnt_writeopcount;
1989 if (mp->mnt_vfs_ops == 0) {
1990 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0);
1995 vfs_dump_mount_counters(mp);
1996 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && c == 0)
1997 wakeup(&mp->mnt_writeopcount);
2002 * Filesystem secondary write operation has completed. If we are
2003 * suspending and this operation is the last one, notify the suspender
2004 * that the suspension is now in effect.
2007 vn_finished_secondary_write(struct mount *mp)
2013 mp->mnt_secondary_writes--;
2014 if (mp->mnt_secondary_writes < 0)
2015 panic("vn_finished_secondary_write: neg cnt");
2016 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
2017 mp->mnt_secondary_writes <= 0)
2018 wakeup(&mp->mnt_secondary_writes);
2023 * Request a filesystem to suspend write operations.
2026 vfs_write_suspend(struct mount *mp, int flags)
2033 vfs_assert_mount_counters(mp);
2034 if (mp->mnt_susp_owner == curthread) {
2035 vfs_op_exit_locked(mp);
2039 while (mp->mnt_kern_flag & MNTK_SUSPEND)
2040 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0);
2043 * Unmount holds a write reference on the mount point. If we
2044 * own busy reference and drain for writers, we deadlock with
2045 * the reference draining in the unmount path. Callers of
2046 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if
2047 * vfs_busy() reference is owned and caller is not in the
2050 if ((flags & VS_SKIP_UNMOUNT) != 0 &&
2051 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) {
2052 vfs_op_exit_locked(mp);
2057 mp->mnt_kern_flag |= MNTK_SUSPEND;
2058 mp->mnt_susp_owner = curthread;
2059 if (mp->mnt_writeopcount > 0)
2060 (void) msleep(&mp->mnt_writeopcount,
2061 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0);
2064 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) {
2065 vfs_write_resume(mp, 0);
2066 /* vfs_write_resume does vfs_op_exit() for us */
2072 * Request a filesystem to resume write operations.
2075 vfs_write_resume(struct mount *mp, int flags)
2079 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
2080 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner"));
2081 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 |
2083 mp->mnt_susp_owner = NULL;
2084 wakeup(&mp->mnt_writeopcount);
2085 wakeup(&mp->mnt_flag);
2086 curthread->td_pflags &= ~TDP_IGNSUSP;
2087 if ((flags & VR_START_WRITE) != 0) {
2089 mp->mnt_writeopcount++;
2092 if ((flags & VR_NO_SUSPCLR) == 0)
2095 } else if ((flags & VR_START_WRITE) != 0) {
2097 vn_start_write_refed(mp, 0, true);
2104 * Helper loop around vfs_write_suspend() for filesystem unmount VFS
2108 vfs_write_suspend_umnt(struct mount *mp)
2112 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0,
2113 ("vfs_write_suspend_umnt: recursed"));
2115 /* dounmount() already called vn_start_write(). */
2117 vn_finished_write(mp);
2118 error = vfs_write_suspend(mp, 0);
2120 vn_start_write(NULL, &mp, V_WAIT);
2124 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0)
2127 vn_start_write(NULL, &mp, V_WAIT);
2129 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2);
2130 wakeup(&mp->mnt_flag);
2132 curthread->td_pflags |= TDP_IGNSUSP;
2137 * Implement kqueues for files by translating it to vnode operation.
2140 vn_kqfilter(struct file *fp, struct knote *kn)
2143 return (VOP_KQFILTER(fp->f_vnode, kn));
2147 vn_kqfilter_opath(struct file *fp, struct knote *kn)
2149 if ((fp->f_flag & FKQALLOWED) == 0)
2151 return (vn_kqfilter(fp, kn));
2155 * Simplified in-kernel wrapper calls for extended attribute access.
2156 * Both calls pass in a NULL credential, authorizing as "kernel" access.
2157 * Set IO_NODELOCKED in ioflg if the vnode is already locked.
2160 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace,
2161 const char *attrname, int *buflen, char *buf, struct thread *td)
2167 iov.iov_len = *buflen;
2170 auio.uio_iov = &iov;
2171 auio.uio_iovcnt = 1;
2172 auio.uio_rw = UIO_READ;
2173 auio.uio_segflg = UIO_SYSSPACE;
2175 auio.uio_offset = 0;
2176 auio.uio_resid = *buflen;
2178 if ((ioflg & IO_NODELOCKED) == 0)
2179 vn_lock(vp, LK_SHARED | LK_RETRY);
2181 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2183 /* authorize attribute retrieval as kernel */
2184 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL,
2187 if ((ioflg & IO_NODELOCKED) == 0)
2191 *buflen = *buflen - auio.uio_resid;
2198 * XXX failure mode if partially written?
2201 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace,
2202 const char *attrname, int buflen, char *buf, struct thread *td)
2209 iov.iov_len = buflen;
2212 auio.uio_iov = &iov;
2213 auio.uio_iovcnt = 1;
2214 auio.uio_rw = UIO_WRITE;
2215 auio.uio_segflg = UIO_SYSSPACE;
2217 auio.uio_offset = 0;
2218 auio.uio_resid = buflen;
2220 if ((ioflg & IO_NODELOCKED) == 0) {
2221 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2223 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2226 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2228 /* authorize attribute setting as kernel */
2229 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td);
2231 if ((ioflg & IO_NODELOCKED) == 0) {
2232 vn_finished_write(mp);
2240 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace,
2241 const char *attrname, struct thread *td)
2246 if ((ioflg & IO_NODELOCKED) == 0) {
2247 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2249 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2252 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2254 /* authorize attribute removal as kernel */
2255 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td);
2256 if (error == EOPNOTSUPP)
2257 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL,
2260 if ((ioflg & IO_NODELOCKED) == 0) {
2261 vn_finished_write(mp);
2269 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags,
2273 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp));
2277 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp)
2280 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino,
2285 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg,
2286 int lkflags, struct vnode **rvp)
2291 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get");
2293 ltype = VOP_ISLOCKED(vp);
2294 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED,
2295 ("vn_vget_ino: vp not locked"));
2296 error = vfs_busy(mp, MBF_NOWAIT);
2300 error = vfs_busy(mp, 0);
2301 vn_lock(vp, ltype | LK_RETRY);
2305 if (VN_IS_DOOMED(vp)) {
2311 error = alloc(mp, alloc_arg, lkflags, rvp);
2313 if (error != 0 || *rvp != vp)
2314 vn_lock(vp, ltype | LK_RETRY);
2315 if (VN_IS_DOOMED(vp)) {
2328 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio,
2332 if (vp->v_type != VREG || td == NULL)
2334 if ((uoff_t)uio->uio_offset + uio->uio_resid >
2335 lim_cur(td, RLIMIT_FSIZE)) {
2336 PROC_LOCK(td->td_proc);
2337 kern_psignal(td->td_proc, SIGXFSZ);
2338 PROC_UNLOCK(td->td_proc);
2345 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
2352 vn_lock(vp, LK_SHARED | LK_RETRY);
2353 AUDIT_ARG_VNODE1(vp);
2356 return (setfmode(td, active_cred, vp, mode));
2360 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
2367 vn_lock(vp, LK_SHARED | LK_RETRY);
2368 AUDIT_ARG_VNODE1(vp);
2371 return (setfown(td, active_cred, vp, uid, gid));
2375 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end)
2379 if ((object = vp->v_object) == NULL)
2381 VM_OBJECT_WLOCK(object);
2382 vm_object_page_remove(object, start, end, 0);
2383 VM_OBJECT_WUNLOCK(object);
2387 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred)
2395 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
2396 ("Wrong command %lu", cmd));
2398 if (vn_lock(vp, LK_SHARED) != 0)
2400 if (vp->v_type != VREG) {
2404 error = VOP_GETATTR(vp, &va, cred);
2408 if (noff >= va.va_size) {
2412 bsize = vp->v_mount->mnt_stat.f_iosize;
2413 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize -
2415 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL);
2416 if (error == EOPNOTSUPP) {
2420 if ((bnp == -1 && cmd == FIOSEEKHOLE) ||
2421 (bnp != -1 && cmd == FIOSEEKDATA)) {
2428 if (noff > va.va_size)
2430 /* noff == va.va_size. There is an implicit hole at the end of file. */
2431 if (cmd == FIOSEEKDATA)
2441 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td)
2446 off_t foffset, size;
2449 cred = td->td_ucred;
2451 foffset = foffset_lock(fp, 0);
2452 noneg = (vp->v_type != VCHR);
2458 (offset > 0 && foffset > OFF_MAX - offset))) {
2465 vn_lock(vp, LK_SHARED | LK_RETRY);
2466 error = VOP_GETATTR(vp, &vattr, cred);
2472 * If the file references a disk device, then fetch
2473 * the media size and use that to determine the ending
2476 if (vattr.va_size == 0 && vp->v_type == VCHR &&
2477 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0)
2478 vattr.va_size = size;
2480 (vattr.va_size > OFF_MAX ||
2481 (offset > 0 && vattr.va_size > OFF_MAX - offset))) {
2485 offset += vattr.va_size;
2490 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td);
2491 if (error == ENOTTY)
2495 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td);
2496 if (error == ENOTTY)
2502 if (error == 0 && noneg && offset < 0)
2506 VFS_KNOTE_UNLOCKED(vp, 0);
2507 td->td_uretoff.tdu_off = offset;
2509 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0);
2514 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred,
2520 * Grant permission if the caller is the owner of the file, or
2521 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on
2522 * on the file. If the time pointer is null, then write
2523 * permission on the file is also sufficient.
2525 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes:
2526 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES
2527 * will be allowed to set the times [..] to the current
2530 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td);
2531 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0)
2532 error = VOP_ACCESS(vp, VWRITE, cred, td);
2537 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
2542 if (fp->f_type == DTYPE_FIFO)
2543 kif->kf_type = KF_TYPE_FIFO;
2545 kif->kf_type = KF_TYPE_VNODE;
2548 FILEDESC_SUNLOCK(fdp);
2549 error = vn_fill_kinfo_vnode(vp, kif);
2551 FILEDESC_SLOCK(fdp);
2556 vn_fill_junk(struct kinfo_file *kif)
2561 * Simulate vn_fullpath returning changing values for a given
2562 * vp during e.g. coredump.
2564 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1;
2565 olen = strlen(kif->kf_path);
2567 strcpy(&kif->kf_path[len - 1], "$");
2569 for (; olen < len; olen++)
2570 strcpy(&kif->kf_path[olen], "A");
2574 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif)
2577 char *fullpath, *freepath;
2580 kif->kf_un.kf_file.kf_file_type = vntype_to_kinfo(vp->v_type);
2583 error = vn_fullpath(vp, &fullpath, &freepath);
2585 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
2587 if (freepath != NULL)
2588 free(freepath, M_TEMP);
2590 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path,
2595 * Retrieve vnode attributes.
2597 va.va_fsid = VNOVAL;
2599 vn_lock(vp, LK_SHARED | LK_RETRY);
2600 error = VOP_GETATTR(vp, &va, curthread->td_ucred);
2604 if (va.va_fsid != VNOVAL)
2605 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid;
2607 kif->kf_un.kf_file.kf_file_fsid =
2608 vp->v_mount->mnt_stat.f_fsid.val[0];
2609 kif->kf_un.kf_file.kf_file_fsid_freebsd11 =
2610 kif->kf_un.kf_file.kf_file_fsid; /* truncate */
2611 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid;
2612 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode);
2613 kif->kf_un.kf_file.kf_file_size = va.va_size;
2614 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev;
2615 kif->kf_un.kf_file.kf_file_rdev_freebsd11 =
2616 kif->kf_un.kf_file.kf_file_rdev; /* truncate */
2621 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
2622 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
2626 struct pmckern_map_in pkm;
2632 boolean_t writecounted;
2635 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
2636 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
2638 * POSIX shared-memory objects are defined to have
2639 * kernel persistence, and are not defined to support
2640 * read(2)/write(2) -- or even open(2). Thus, we can
2641 * use MAP_ASYNC to trade on-disk coherence for speed.
2642 * The shm_open(3) library routine turns on the FPOSIXSHM
2643 * flag to request this behavior.
2645 if ((fp->f_flag & FPOSIXSHM) != 0)
2646 flags |= MAP_NOSYNC;
2651 * Ensure that file and memory protections are
2652 * compatible. Note that we only worry about
2653 * writability if mapping is shared; in this case,
2654 * current and max prot are dictated by the open file.
2655 * XXX use the vnode instead? Problem is: what
2656 * credentials do we use for determination? What if
2657 * proc does a setuid?
2660 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) {
2661 maxprot = VM_PROT_NONE;
2662 if ((prot & VM_PROT_EXECUTE) != 0)
2665 maxprot = VM_PROT_EXECUTE;
2666 if ((fp->f_flag & FREAD) != 0)
2667 maxprot |= VM_PROT_READ;
2668 else if ((prot & VM_PROT_READ) != 0)
2672 * If we are sharing potential changes via MAP_SHARED and we
2673 * are trying to get write permission although we opened it
2674 * without asking for it, bail out.
2676 if ((flags & MAP_SHARED) != 0) {
2677 if ((fp->f_flag & FWRITE) != 0)
2678 maxprot |= VM_PROT_WRITE;
2679 else if ((prot & VM_PROT_WRITE) != 0)
2682 maxprot |= VM_PROT_WRITE;
2683 cap_maxprot |= VM_PROT_WRITE;
2685 maxprot &= cap_maxprot;
2688 * For regular files and shared memory, POSIX requires that
2689 * the value of foff be a legitimate offset within the data
2690 * object. In particular, negative offsets are invalid.
2691 * Blocking negative offsets and overflows here avoids
2692 * possible wraparound or user-level access into reserved
2693 * ranges of the data object later. In contrast, POSIX does
2694 * not dictate how offsets are used by device drivers, so in
2695 * the case of a device mapping a negative offset is passed
2702 foff > OFF_MAX - size)
2705 writecounted = FALSE;
2706 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp,
2707 &foff, &object, &writecounted);
2710 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
2711 foff, writecounted, td);
2714 * If this mapping was accounted for in the vnode's
2715 * writecount, then undo that now.
2718 vm_pager_release_writecount(object, 0, size);
2719 vm_object_deallocate(object);
2722 /* Inform hwpmc(4) if an executable is being mapped. */
2723 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) {
2724 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) {
2726 pkm.pm_address = (uintptr_t) *addr;
2727 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_MMAP, (void *) &pkm);
2735 vn_fsid(struct vnode *vp, struct vattr *va)
2739 f = &vp->v_mount->mnt_stat.f_fsid;
2740 va->va_fsid = (uint32_t)f->val[1];
2741 va->va_fsid <<= sizeof(f->val[1]) * NBBY;
2742 va->va_fsid += (uint32_t)f->val[0];
2746 vn_fsync_buf(struct vnode *vp, int waitfor)
2748 struct buf *bp, *nbp;
2751 int error, maxretry;
2754 maxretry = 10000; /* large, arbitrarily chosen */
2756 if (vp->v_type == VCHR) {
2758 mp = vp->v_rdev->si_mountpt;
2765 * MARK/SCAN initialization to avoid infinite loops.
2767 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) {
2768 bp->b_vflags &= ~BV_SCANNED;
2773 * Flush all dirty buffers associated with a vnode.
2776 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
2777 if ((bp->b_vflags & BV_SCANNED) != 0)
2779 bp->b_vflags |= BV_SCANNED;
2780 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) {
2781 if (waitfor != MNT_WAIT)
2784 LK_EXCLUSIVE | LK_INTERLOCK | LK_SLEEPFAIL,
2785 BO_LOCKPTR(bo)) != 0) {
2792 KASSERT(bp->b_bufobj == bo,
2793 ("bp %p wrong b_bufobj %p should be %p",
2794 bp, bp->b_bufobj, bo));
2795 if ((bp->b_flags & B_DELWRI) == 0)
2796 panic("fsync: not dirty");
2797 if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) {
2803 if (maxretry < 1000)
2804 pause("dirty", hz < 1000 ? 1 : hz / 1000);
2810 * If synchronous the caller expects us to completely resolve all
2811 * dirty buffers in the system. Wait for in-progress I/O to
2812 * complete (which could include background bitmap writes), then
2813 * retry if dirty blocks still exist.
2815 if (waitfor == MNT_WAIT) {
2816 bufobj_wwait(bo, 0, 0);
2817 if (bo->bo_dirty.bv_cnt > 0) {
2819 * If we are unable to write any of these buffers
2820 * then we fail now rather than trying endlessly
2821 * to write them out.
2823 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs)
2824 if ((error = bp->b_error) != 0)
2826 if ((mp != NULL && mp->mnt_secondary_writes > 0) ||
2827 (error == 0 && --maxretry >= 0))
2835 vn_printf(vp, "fsync: giving up on dirty (error = %d) ", error);
2841 * Copies a byte range from invp to outvp. Calls VOP_COPY_FILE_RANGE()
2842 * or vn_generic_copy_file_range() after rangelocking the byte ranges,
2843 * to do the actual copy.
2844 * vn_generic_copy_file_range() is factored out, so it can be called
2845 * from a VOP_COPY_FILE_RANGE() call as well, but handles vnodes from
2846 * different file systems.
2849 vn_copy_file_range(struct vnode *invp, off_t *inoffp, struct vnode *outvp,
2850 off_t *outoffp, size_t *lenp, unsigned int flags, struct ucred *incred,
2851 struct ucred *outcred, struct thread *fsize_td)
2858 *lenp = 0; /* For error returns. */
2861 /* Do some sanity checks on the arguments. */
2862 if (invp->v_type == VDIR || outvp->v_type == VDIR)
2864 else if (*inoffp < 0 || *outoffp < 0 ||
2865 invp->v_type != VREG || outvp->v_type != VREG)
2870 /* Ensure offset + len does not wrap around. */
2873 if (uval > INT64_MAX)
2874 len = INT64_MAX - *inoffp;
2877 if (uval > INT64_MAX)
2878 len = INT64_MAX - *outoffp;
2883 * If the two vnode are for the same file system, call
2884 * VOP_COPY_FILE_RANGE(), otherwise call vn_generic_copy_file_range()
2885 * which can handle copies across multiple file systems.
2888 if (invp->v_mount == outvp->v_mount)
2889 error = VOP_COPY_FILE_RANGE(invp, inoffp, outvp, outoffp,
2890 lenp, flags, incred, outcred, fsize_td);
2892 error = vn_generic_copy_file_range(invp, inoffp, outvp,
2893 outoffp, lenp, flags, incred, outcred, fsize_td);
2899 * Test len bytes of data starting at dat for all bytes == 0.
2900 * Return true if all bytes are zero, false otherwise.
2901 * Expects dat to be well aligned.
2904 mem_iszero(void *dat, int len)
2910 for (p = dat; len > 0; len -= sizeof(*p), p++) {
2911 if (len >= sizeof(*p)) {
2915 cp = (const char *)p;
2916 for (i = 0; i < len; i++, cp++)
2925 * Look for a hole in the output file and, if found, adjust *outoffp
2926 * and *xferp to skip past the hole.
2927 * *xferp is the entire hole length to be written and xfer2 is how many bytes
2928 * to be written as 0's upon return.
2931 vn_skip_hole(struct vnode *outvp, off_t xfer2, off_t *outoffp, off_t *xferp,
2932 off_t *dataoffp, off_t *holeoffp, struct ucred *cred)
2937 if (*holeoffp == 0 || *holeoffp <= *outoffp) {
2938 *dataoffp = *outoffp;
2939 error = VOP_IOCTL(outvp, FIOSEEKDATA, dataoffp, 0, cred,
2942 *holeoffp = *dataoffp;
2943 error = VOP_IOCTL(outvp, FIOSEEKHOLE, holeoffp, 0, cred,
2946 if (error != 0 || *holeoffp == *dataoffp) {
2948 * Since outvp is unlocked, it may be possible for
2949 * another thread to do a truncate(), lseek(), write()
2950 * creating a hole at startoff between the above
2951 * VOP_IOCTL() calls, if the other thread does not do
2953 * If that happens, *holeoffp == *dataoffp and finding
2954 * the hole has failed, so disable vn_skip_hole().
2956 *holeoffp = -1; /* Disable use of vn_skip_hole(). */
2959 KASSERT(*dataoffp >= *outoffp,
2960 ("vn_skip_hole: dataoff=%jd < outoff=%jd",
2961 (intmax_t)*dataoffp, (intmax_t)*outoffp));
2962 KASSERT(*holeoffp > *dataoffp,
2963 ("vn_skip_hole: holeoff=%jd <= dataoff=%jd",
2964 (intmax_t)*holeoffp, (intmax_t)*dataoffp));
2968 * If there is a hole before the data starts, advance *outoffp and
2969 * *xferp past the hole.
2971 if (*dataoffp > *outoffp) {
2972 delta = *dataoffp - *outoffp;
2973 if (delta >= *xferp) {
2974 /* Entire *xferp is a hole. */
2981 xfer2 = MIN(xfer2, *xferp);
2985 * If a hole starts before the end of this xfer2, reduce this xfer2 so
2986 * that the write ends at the start of the hole.
2987 * *holeoffp should always be greater than *outoffp, but for the
2988 * non-INVARIANTS case, check this to make sure xfer2 remains a sane
2991 if (*holeoffp > *outoffp && *holeoffp < *outoffp + xfer2)
2992 xfer2 = *holeoffp - *outoffp;
2997 * Write an xfer sized chunk to outvp in blksize blocks from dat.
2998 * dat is a maximum of blksize in length and can be written repeatedly in
3000 * If growfile == true, just grow the file via vn_truncate_locked() instead
3001 * of doing actual writes.
3002 * If checkhole == true, a hole is being punched, so skip over any hole
3003 * already in the output file.
3006 vn_write_outvp(struct vnode *outvp, char *dat, off_t outoff, off_t xfer,
3007 u_long blksize, bool growfile, bool checkhole, struct ucred *cred)
3010 off_t dataoff, holeoff, xfer2;
3014 * Loop around doing writes of blksize until write has been completed.
3015 * Lock/unlock on each loop iteration so that a bwillwrite() can be
3016 * done for each iteration, since the xfer argument can be very
3017 * large if there is a large hole to punch in the output file.
3022 xfer2 = MIN(xfer, blksize);
3025 * Punching a hole. Skip writing if there is
3026 * already a hole in the output file.
3028 xfer2 = vn_skip_hole(outvp, xfer2, &outoff, &xfer,
3029 &dataoff, &holeoff, cred);
3034 KASSERT(xfer2 > 0, ("vn_write_outvp: xfer2=%jd",
3039 error = vn_start_write(outvp, &mp, V_WAIT);
3043 error = vn_lock(outvp, LK_EXCLUSIVE);
3045 error = vn_truncate_locked(outvp, outoff + xfer,
3050 if (MNT_SHARED_WRITES(mp))
3053 lckf = LK_EXCLUSIVE;
3054 error = vn_lock(outvp, lckf);
3056 error = vn_rdwr(UIO_WRITE, outvp, dat, xfer2,
3057 outoff, UIO_SYSSPACE, IO_NODELOCKED,
3058 curthread->td_ucred, cred, NULL, curthread);
3065 vn_finished_write(mp);
3066 } while (!growfile && xfer > 0 && error == 0);
3071 * Copy a byte range of one file to another. This function can handle the
3072 * case where invp and outvp are on different file systems.
3073 * It can also be called by a VOP_COPY_FILE_RANGE() to do the work, if there
3074 * is no better file system specific way to do it.
3077 vn_generic_copy_file_range(struct vnode *invp, off_t *inoffp,
3078 struct vnode *outvp, off_t *outoffp, size_t *lenp, unsigned int flags,
3079 struct ucred *incred, struct ucred *outcred, struct thread *fsize_td)
3084 off_t startoff, endoff, xfer, xfer2;
3086 int error, interrupted;
3087 bool cantseek, readzeros, eof, lastblock;
3089 size_t copylen, len, rem, savlen;
3091 long holein, holeout;
3093 holein = holeout = 0;
3094 savlen = len = *lenp;
3099 error = vn_lock(invp, LK_SHARED);
3102 if (VOP_PATHCONF(invp, _PC_MIN_HOLE_SIZE, &holein) != 0)
3107 error = vn_start_write(outvp, &mp, V_WAIT);
3109 error = vn_lock(outvp, LK_EXCLUSIVE);
3112 * If fsize_td != NULL, do a vn_rlimit_fsize() call,
3113 * now that outvp is locked.
3115 if (fsize_td != NULL) {
3116 io.uio_offset = *outoffp;
3118 error = vn_rlimit_fsize(outvp, &io, fsize_td);
3122 if (VOP_PATHCONF(outvp, _PC_MIN_HOLE_SIZE, &holeout) != 0)
3125 * Holes that are past EOF do not need to be written as a block
3126 * of zero bytes. So, truncate the output file as far as
3127 * possible and then use va.va_size to decide if writing 0
3128 * bytes is necessary in the loop below.
3131 error = VOP_GETATTR(outvp, &va, outcred);
3132 if (error == 0 && va.va_size > *outoffp && va.va_size <=
3135 error = mac_vnode_check_write(curthread->td_ucred,
3139 error = vn_truncate_locked(outvp, *outoffp,
3142 va.va_size = *outoffp;
3147 vn_finished_write(mp);
3152 * Set the blksize to the larger of the hole sizes for invp and outvp.
3153 * If hole sizes aren't available, set the blksize to the larger
3154 * f_iosize of invp and outvp.
3155 * This code expects the hole sizes and f_iosizes to be powers of 2.
3156 * This value is clipped at 4Kbytes and 1Mbyte.
3158 blksize = MAX(holein, holeout);
3160 /* Clip len to end at an exact multiple of hole size. */
3162 rem = *inoffp % blksize;
3164 rem = blksize - rem;
3165 if (len > rem && len - rem > blksize)
3166 len = savlen = rounddown(len - rem, blksize) + rem;
3170 blksize = MAX(invp->v_mount->mnt_stat.f_iosize,
3171 outvp->v_mount->mnt_stat.f_iosize);
3174 else if (blksize > 1024 * 1024)
3175 blksize = 1024 * 1024;
3176 dat = malloc(blksize, M_TEMP, M_WAITOK);
3179 * If VOP_IOCTL(FIOSEEKHOLE) works for invp, use it and FIOSEEKDATA
3180 * to find holes. Otherwise, just scan the read block for all 0s
3181 * in the inner loop where the data copying is done.
3182 * Note that some file systems such as NFSv3, NFSv4.0 and NFSv4.1 may
3183 * support holes on the server, but do not support FIOSEEKHOLE.
3186 while (len > 0 && error == 0 && !eof && interrupted == 0) {
3187 endoff = 0; /* To shut up compilers. */
3193 * Find the next data area. If there is just a hole to EOF,
3194 * FIOSEEKDATA should fail and then we drop down into the
3195 * inner loop and create the hole on the outvp file.
3196 * (I do not know if any file system will report a hole to
3197 * EOF via FIOSEEKHOLE, but I am pretty sure FIOSEEKDATA
3198 * will fail for those file systems.)
3200 * For input files that don't support FIOSEEKDATA/FIOSEEKHOLE,
3201 * the code just falls through to the inner copy loop.
3205 error = VOP_IOCTL(invp, FIOSEEKDATA, &startoff, 0,
3209 error = VOP_IOCTL(invp, FIOSEEKHOLE, &endoff, 0,
3212 * Since invp is unlocked, it may be possible for
3213 * another thread to do a truncate(), lseek(), write()
3214 * creating a hole at startoff between the above
3215 * VOP_IOCTL() calls, if the other thread does not do
3217 * If that happens, startoff == endoff and finding
3218 * the hole has failed, so set an error.
3220 if (error == 0 && startoff == endoff)
3221 error = EINVAL; /* Any error. Reset to 0. */
3224 if (startoff > *inoffp) {
3225 /* Found hole before data block. */
3226 xfer = MIN(startoff - *inoffp, len);
3227 if (*outoffp < va.va_size) {
3228 /* Must write 0s to punch hole. */
3229 xfer2 = MIN(va.va_size - *outoffp,
3231 memset(dat, 0, MIN(xfer2, blksize));
3232 error = vn_write_outvp(outvp, dat,
3233 *outoffp, xfer2, blksize, false,
3234 holeout > 0, outcred);
3237 if (error == 0 && *outoffp + xfer >
3238 va.va_size && xfer == len)
3239 /* Grow last block. */
3240 error = vn_write_outvp(outvp, dat,
3241 *outoffp, xfer, blksize, true,
3248 interrupted = sig_intr();
3251 copylen = MIN(len, endoff - startoff);
3263 * Set first xfer to end at a block boundary, so that
3264 * holes are more likely detected in the loop below via
3265 * the for all bytes 0 method.
3267 xfer -= (*inoffp % blksize);
3269 /* Loop copying the data block. */
3270 while (copylen > 0 && error == 0 && !eof && interrupted == 0) {
3273 error = vn_lock(invp, LK_SHARED);
3276 error = vn_rdwr(UIO_READ, invp, dat, xfer,
3277 startoff, UIO_SYSSPACE, IO_NODELOCKED,
3278 curthread->td_ucred, incred, &aresid,
3282 if (error == 0 && aresid > 0) {
3283 /* Stop the copy at EOF on the input file. */
3290 * Skip the write for holes past the initial EOF
3291 * of the output file, unless this is the last
3292 * write of the output file at EOF.
3294 readzeros = cantseek ? mem_iszero(dat, xfer) :
3298 if (!cantseek || *outoffp < va.va_size ||
3299 lastblock || !readzeros)
3300 error = vn_write_outvp(outvp, dat,
3301 *outoffp, xfer, blksize,
3302 readzeros && lastblock &&
3303 *outoffp >= va.va_size, false,
3312 interrupted = sig_intr();
3319 *lenp = savlen - len;
3325 vn_fallocate(struct file *fp, off_t offset, off_t len, struct thread *td)
3329 off_t olen, ooffset;
3332 int audited_vnode1 = 0;
3336 if (vp->v_type != VREG)
3339 /* Allocating blocks may take a long time, so iterate. */
3346 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
3349 error = vn_lock(vp, LK_EXCLUSIVE);
3351 vn_finished_write(mp);
3355 if (!audited_vnode1) {
3356 AUDIT_ARG_VNODE1(vp);
3361 error = mac_vnode_check_write(td->td_ucred, fp->f_cred, vp);
3364 error = VOP_ALLOCATE(vp, &offset, &len);
3366 vn_finished_write(mp);
3368 if (olen + ooffset != offset + len) {
3369 panic("offset + len changed from %jx/%jx to %jx/%jx",
3370 ooffset, olen, offset, len);
3372 if (error != 0 || len == 0)
3374 KASSERT(olen > len, ("Iteration did not make progress?"));
3381 static u_long vn_lock_pair_pause_cnt;
3382 SYSCTL_ULONG(_debug, OID_AUTO, vn_lock_pair_pause, CTLFLAG_RD,
3383 &vn_lock_pair_pause_cnt, 0,
3384 "Count of vn_lock_pair deadlocks");
3386 u_int vn_lock_pair_pause_max;
3387 SYSCTL_UINT(_debug, OID_AUTO, vn_lock_pair_pause_max, CTLFLAG_RW,
3388 &vn_lock_pair_pause_max, 0,
3389 "Max ticks for vn_lock_pair deadlock avoidance sleep");
3392 vn_lock_pair_pause(const char *wmesg)
3394 atomic_add_long(&vn_lock_pair_pause_cnt, 1);
3395 pause(wmesg, prng32_bounded(vn_lock_pair_pause_max));
3399 * Lock pair of vnodes vp1, vp2, avoiding lock order reversal.
3400 * vp1_locked indicates whether vp1 is exclusively locked; if not, vp1
3401 * must be unlocked. Same for vp2 and vp2_locked. One of the vnodes
3404 * The function returns with both vnodes exclusively locked, and
3405 * guarantees that it does not create lock order reversal with other
3406 * threads during its execution. Both vnodes could be unlocked
3407 * temporary (and reclaimed).
3410 vn_lock_pair(struct vnode *vp1, bool vp1_locked, struct vnode *vp2,
3415 if (vp1 == NULL && vp2 == NULL)
3419 ASSERT_VOP_ELOCKED(vp1, "vp1");
3421 ASSERT_VOP_UNLOCKED(vp1, "vp1");
3427 ASSERT_VOP_ELOCKED(vp2, "vp2");
3429 ASSERT_VOP_UNLOCKED(vp2, "vp2");
3433 if (!vp1_locked && !vp2_locked) {
3434 vn_lock(vp1, LK_EXCLUSIVE | LK_RETRY);
3439 if (vp1_locked && vp2_locked)
3441 if (vp1_locked && vp2 != NULL) {
3443 error = VOP_LOCK1(vp2, LK_EXCLUSIVE | LK_NOWAIT,
3444 __FILE__, __LINE__);
3449 vn_lock_pair_pause("vlp1");
3451 vn_lock(vp2, LK_EXCLUSIVE | LK_RETRY);
3454 if (vp2_locked && vp1 != NULL) {
3456 error = VOP_LOCK1(vp1, LK_EXCLUSIVE | LK_NOWAIT,
3457 __FILE__, __LINE__);
3462 vn_lock_pair_pause("vlp2");
3464 vn_lock(vp1, LK_EXCLUSIVE | LK_RETRY);
3469 ASSERT_VOP_ELOCKED(vp1, "vp1 ret");
3471 ASSERT_VOP_ELOCKED(vp2, "vp2 ret");