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_stat_t vn_statfile;
106 static fo_close_t vn_closefile;
107 static fo_mmap_t vn_mmap;
108 static fo_fallocate_t vn_fallocate;
110 struct fileops vnops = {
111 .fo_read = vn_io_fault,
112 .fo_write = vn_io_fault,
113 .fo_truncate = vn_truncate,
114 .fo_ioctl = vn_ioctl,
116 .fo_kqfilter = vn_kqfilter,
117 .fo_stat = vn_statfile,
118 .fo_close = vn_closefile,
119 .fo_chmod = vn_chmod,
120 .fo_chown = vn_chown,
121 .fo_sendfile = vn_sendfile,
123 .fo_fill_kinfo = vn_fill_kinfo,
125 .fo_fallocate = vn_fallocate,
126 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE
129 const u_int io_hold_cnt = 16;
130 static int vn_io_fault_enable = 1;
131 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RWTUN,
132 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance");
133 static int vn_io_fault_prefault = 0;
134 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RWTUN,
135 &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting");
136 static int vn_io_pgcache_read_enable = 1;
137 SYSCTL_INT(_debug, OID_AUTO, vn_io_pgcache_read_enable, CTLFLAG_RWTUN,
138 &vn_io_pgcache_read_enable, 0,
139 "Enable copying from page cache for reads, avoiding fs");
140 static u_long vn_io_faults_cnt;
141 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD,
142 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers");
144 static int vfs_allow_read_dir = 0;
145 SYSCTL_INT(_security_bsd, OID_AUTO, allow_read_dir, CTLFLAG_RW,
146 &vfs_allow_read_dir, 0,
147 "Enable read(2) of directory by root for filesystems that support it");
150 * Returns true if vn_io_fault mode of handling the i/o request should
154 do_vn_io_fault(struct vnode *vp, struct uio *uio)
158 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG &&
159 (mp = vp->v_mount) != NULL &&
160 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable);
164 * Structure used to pass arguments to vn_io_fault1(), to do either
165 * file- or vnode-based I/O calls.
167 struct vn_io_fault_args {
175 struct fop_args_tag {
179 struct vop_args_tag {
185 static int vn_io_fault1(struct vnode *vp, struct uio *uio,
186 struct vn_io_fault_args *args, struct thread *td);
189 vn_open(struct nameidata *ndp, int *flagp, int cmode, struct file *fp)
191 struct thread *td = ndp->ni_cnd.cn_thread;
193 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp));
197 open2nameif(int fmode, u_int vn_open_flags)
201 res = ISOPEN | LOCKLEAF;
202 if ((fmode & O_BENEATH) != 0)
204 if ((fmode & O_RESOLVE_BENEATH) != 0)
206 if ((vn_open_flags & VN_OPEN_NOAUDIT) == 0)
208 if ((vn_open_flags & VN_OPEN_NOCAPCHECK) != 0)
214 * Common code for vnode open operations via a name lookup.
215 * Lookup the vnode and invoke VOP_CREATE if needed.
216 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
218 * Note that this does NOT free nameidata for the successful case,
219 * due to the NDINIT being done elsewhere.
222 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags,
223 struct ucred *cred, struct file *fp)
227 struct thread *td = ndp->ni_cnd.cn_thread;
229 struct vattr *vap = &vat;
234 if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT |
235 O_EXCL | O_DIRECTORY))
237 else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) {
238 ndp->ni_cnd.cn_nameiop = CREATE;
239 ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags);
241 * Set NOCACHE to avoid flushing the cache when
242 * rolling in many files at once.
244 ndp->ni_cnd.cn_flags |= LOCKPARENT | NOCACHE;
245 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
246 ndp->ni_cnd.cn_flags |= FOLLOW;
247 if ((vn_open_flags & VN_OPEN_INVFS) == 0)
249 if ((error = namei(ndp)) != 0)
251 if (ndp->ni_vp == NULL) {
254 vap->va_mode = cmode;
256 vap->va_vaflags |= VA_EXCLUSIVE;
257 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) {
258 NDFREE(ndp, NDF_ONLY_PNBUF);
260 if ((error = vn_start_write(NULL, &mp,
261 V_XSLEEP | PCATCH)) != 0)
266 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0)
267 ndp->ni_cnd.cn_flags |= MAKEENTRY;
269 error = mac_vnode_check_create(cred, ndp->ni_dvp,
273 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
276 vn_finished_write(mp);
278 NDFREE(ndp, NDF_ONLY_PNBUF);
279 if (error == ERELOOKUP) {
288 if (ndp->ni_dvp == ndp->ni_vp)
294 if (fmode & O_EXCL) {
298 if (vp->v_type == VDIR) {
305 ndp->ni_cnd.cn_nameiop = LOOKUP;
306 ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags);
307 ndp->ni_cnd.cn_flags |= (fmode & O_NOFOLLOW) != 0 ? NOFOLLOW :
309 if ((fmode & FWRITE) == 0)
310 ndp->ni_cnd.cn_flags |= LOCKSHARED;
311 if ((error = namei(ndp)) != 0)
315 error = vn_open_vnode(vp, fmode, cred, td, fp);
321 NDFREE(ndp, NDF_ONLY_PNBUF);
329 vn_open_vnode_advlock(struct vnode *vp, int fmode, struct file *fp)
332 int error, lock_flags, type;
334 ASSERT_VOP_LOCKED(vp, "vn_open_vnode_advlock");
335 if ((fmode & (O_EXLOCK | O_SHLOCK)) == 0)
337 KASSERT(fp != NULL, ("open with flock requires fp"));
338 if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE)
341 lock_flags = VOP_ISLOCKED(vp);
344 lf.l_whence = SEEK_SET;
347 lf.l_type = (fmode & O_EXLOCK) != 0 ? F_WRLCK : F_RDLCK;
349 if ((fmode & FNONBLOCK) == 0)
351 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type);
353 fp->f_flag |= FHASLOCK;
355 vn_lock(vp, lock_flags | LK_RETRY);
356 if (error == 0 && VN_IS_DOOMED(vp))
362 * Common code for vnode open operations once a vnode is located.
363 * Check permissions, and call the VOP_OPEN routine.
366 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred,
367 struct thread *td, struct file *fp)
372 if (vp->v_type == VLNK)
374 if (vp->v_type == VSOCK)
376 if (vp->v_type != VDIR && fmode & O_DIRECTORY)
379 if (fmode & (FWRITE | O_TRUNC)) {
380 if (vp->v_type == VDIR)
388 if ((fmode & O_APPEND) && (fmode & FWRITE))
393 if (fmode & O_VERIFY)
395 error = mac_vnode_check_open(cred, vp, accmode);
399 accmode &= ~(VCREAT | VVERIFY);
401 if ((fmode & O_CREAT) == 0 && accmode != 0) {
402 error = VOP_ACCESS(vp, accmode, cred, td);
406 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
407 vn_lock(vp, LK_UPGRADE | LK_RETRY);
408 error = VOP_OPEN(vp, fmode, cred, td, fp);
412 error = vn_open_vnode_advlock(vp, fmode, fp);
413 if (error == 0 && (fmode & FWRITE) != 0) {
414 error = VOP_ADD_WRITECOUNT(vp, 1);
416 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
417 __func__, vp, vp->v_writecount);
422 * Error from advlock or VOP_ADD_WRITECOUNT() still requires
423 * calling VOP_CLOSE() to pair with earlier VOP_OPEN().
424 * Arrange for that by having fdrop() to use vn_closefile().
427 fp->f_flag |= FOPENFAILED;
429 if (fp->f_ops == &badfileops) {
430 fp->f_type = DTYPE_VNODE;
436 ASSERT_VOP_LOCKED(vp, "vn_open_vnode");
442 * Check for write permissions on the specified vnode.
443 * Prototype text segments cannot be written.
447 vn_writechk(struct vnode *vp)
450 ASSERT_VOP_LOCKED(vp, "vn_writechk");
452 * If there's shared text associated with
453 * the vnode, try to free it up once. If
454 * we fail, we can't allow writing.
466 vn_close1(struct vnode *vp, int flags, struct ucred *file_cred,
467 struct thread *td, bool keep_ref)
470 int error, lock_flags;
472 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 &&
473 MNT_EXTENDED_SHARED(vp->v_mount))
474 lock_flags = LK_SHARED;
476 lock_flags = LK_EXCLUSIVE;
478 vn_start_write(vp, &mp, V_WAIT);
479 vn_lock(vp, lock_flags | LK_RETRY);
480 AUDIT_ARG_VNODE1(vp);
481 if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) {
482 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
483 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
484 __func__, vp, vp->v_writecount);
486 error = VOP_CLOSE(vp, flags, file_cred, td);
491 vn_finished_write(mp);
496 vn_close(struct vnode *vp, int flags, struct ucred *file_cred,
500 return (vn_close1(vp, flags, file_cred, td, false));
504 * Heuristic to detect sequential operation.
507 sequential_heuristic(struct uio *uio, struct file *fp)
511 ASSERT_VOP_LOCKED(fp->f_vnode, __func__);
514 if (fp->f_flag & FRDAHEAD)
515 return (fp->f_seqcount[rw] << IO_SEQSHIFT);
518 * Offset 0 is handled specially. open() sets f_seqcount to 1 so
519 * that the first I/O is normally considered to be slightly
520 * sequential. Seeking to offset 0 doesn't change sequentiality
521 * unless previous seeks have reduced f_seqcount to 0, in which
522 * case offset 0 is not special.
524 if ((uio->uio_offset == 0 && fp->f_seqcount[rw] > 0) ||
525 uio->uio_offset == fp->f_nextoff[rw]) {
527 * f_seqcount is in units of fixed-size blocks so that it
528 * depends mainly on the amount of sequential I/O and not
529 * much on the number of sequential I/O's. The fixed size
530 * of 16384 is hard-coded here since it is (not quite) just
531 * a magic size that works well here. This size is more
532 * closely related to the best I/O size for real disks than
533 * to any block size used by software.
535 if (uio->uio_resid >= IO_SEQMAX * 16384)
536 fp->f_seqcount[rw] = IO_SEQMAX;
538 fp->f_seqcount[rw] += howmany(uio->uio_resid, 16384);
539 if (fp->f_seqcount[rw] > IO_SEQMAX)
540 fp->f_seqcount[rw] = IO_SEQMAX;
542 return (fp->f_seqcount[rw] << IO_SEQSHIFT);
545 /* Not sequential. Quickly draw-down sequentiality. */
546 if (fp->f_seqcount[rw] > 1)
547 fp->f_seqcount[rw] = 1;
549 fp->f_seqcount[rw] = 0;
554 * Package up an I/O request on a vnode into a uio and do it.
557 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset,
558 enum uio_seg segflg, int ioflg, struct ucred *active_cred,
559 struct ucred *file_cred, ssize_t *aresid, struct thread *td)
566 struct vn_io_fault_args args;
567 int error, lock_flags;
569 if (offset < 0 && vp->v_type != VCHR)
571 auio.uio_iov = &aiov;
573 aiov.iov_base = base;
575 auio.uio_resid = len;
576 auio.uio_offset = offset;
577 auio.uio_segflg = segflg;
582 if ((ioflg & IO_NODELOCKED) == 0) {
583 if ((ioflg & IO_RANGELOCKED) == 0) {
584 if (rw == UIO_READ) {
585 rl_cookie = vn_rangelock_rlock(vp, offset,
588 rl_cookie = vn_rangelock_wlock(vp, offset,
594 if (rw == UIO_WRITE) {
595 if (vp->v_type != VCHR &&
596 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH))
599 if (MNT_SHARED_WRITES(mp) ||
600 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount)))
601 lock_flags = LK_SHARED;
603 lock_flags = LK_EXCLUSIVE;
605 lock_flags = LK_SHARED;
606 vn_lock(vp, lock_flags | LK_RETRY);
610 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
612 if ((ioflg & IO_NOMACCHECK) == 0) {
614 error = mac_vnode_check_read(active_cred, file_cred,
617 error = mac_vnode_check_write(active_cred, file_cred,
622 if (file_cred != NULL)
626 if (do_vn_io_fault(vp, &auio)) {
627 args.kind = VN_IO_FAULT_VOP;
630 args.args.vop_args.vp = vp;
631 error = vn_io_fault1(vp, &auio, &args, td);
632 } else if (rw == UIO_READ) {
633 error = VOP_READ(vp, &auio, ioflg, cred);
634 } else /* if (rw == UIO_WRITE) */ {
635 error = VOP_WRITE(vp, &auio, ioflg, cred);
639 *aresid = auio.uio_resid;
641 if (auio.uio_resid && error == 0)
643 if ((ioflg & IO_NODELOCKED) == 0) {
646 vn_finished_write(mp);
649 if (rl_cookie != NULL)
650 vn_rangelock_unlock(vp, rl_cookie);
655 * Package up an I/O request on a vnode into a uio and do it. The I/O
656 * request is split up into smaller chunks and we try to avoid saturating
657 * the buffer cache while potentially holding a vnode locked, so we
658 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield()
659 * to give other processes a chance to lock the vnode (either other processes
660 * core'ing the same binary, or unrelated processes scanning the directory).
663 vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, void *base, size_t len,
664 off_t offset, enum uio_seg segflg, int ioflg, struct ucred *active_cred,
665 struct ucred *file_cred, size_t *aresid, struct thread *td)
674 * Force `offset' to a multiple of MAXBSIZE except possibly
675 * for the first chunk, so that filesystems only need to
676 * write full blocks except possibly for the first and last
679 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE;
683 if (rw != UIO_READ && vp->v_type == VREG)
686 error = vn_rdwr(rw, vp, base, chunk, offset, segflg,
687 ioflg, active_cred, file_cred, &iaresid, td);
688 len -= chunk; /* aresid calc already includes length */
692 base = (char *)base + chunk;
693 kern_yield(PRI_USER);
696 *aresid = len + iaresid;
700 #if OFF_MAX <= LONG_MAX
702 foffset_lock(struct file *fp, int flags)
704 volatile short *flagsp;
708 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
710 if ((flags & FOF_NOLOCK) != 0)
711 return (atomic_load_long(&fp->f_offset));
714 * According to McKusick the vn lock was protecting f_offset here.
715 * It is now protected by the FOFFSET_LOCKED flag.
717 flagsp = &fp->f_vnread_flags;
718 if (atomic_cmpset_acq_16(flagsp, 0, FOFFSET_LOCKED))
719 return (atomic_load_long(&fp->f_offset));
721 sleepq_lock(&fp->f_vnread_flags);
722 state = atomic_load_16(flagsp);
724 if ((state & FOFFSET_LOCKED) == 0) {
725 if (!atomic_fcmpset_acq_16(flagsp, &state,
730 if ((state & FOFFSET_LOCK_WAITING) == 0) {
731 if (!atomic_fcmpset_acq_16(flagsp, &state,
732 state | FOFFSET_LOCK_WAITING))
736 sleepq_add(&fp->f_vnread_flags, NULL, "vofflock", 0, 0);
737 sleepq_wait(&fp->f_vnread_flags, PUSER -1);
739 sleepq_lock(&fp->f_vnread_flags);
740 state = atomic_load_16(flagsp);
742 res = atomic_load_long(&fp->f_offset);
743 sleepq_release(&fp->f_vnread_flags);
748 foffset_unlock(struct file *fp, off_t val, int flags)
750 volatile short *flagsp;
753 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
755 if ((flags & FOF_NOUPDATE) == 0)
756 atomic_store_long(&fp->f_offset, val);
757 if ((flags & FOF_NEXTOFF_R) != 0)
758 fp->f_nextoff[UIO_READ] = val;
759 if ((flags & FOF_NEXTOFF_W) != 0)
760 fp->f_nextoff[UIO_WRITE] = val;
762 if ((flags & FOF_NOLOCK) != 0)
765 flagsp = &fp->f_vnread_flags;
766 state = atomic_load_16(flagsp);
767 if ((state & FOFFSET_LOCK_WAITING) == 0 &&
768 atomic_cmpset_rel_16(flagsp, state, 0))
771 sleepq_lock(&fp->f_vnread_flags);
772 MPASS((fp->f_vnread_flags & FOFFSET_LOCKED) != 0);
773 MPASS((fp->f_vnread_flags & FOFFSET_LOCK_WAITING) != 0);
774 fp->f_vnread_flags = 0;
775 sleepq_broadcast(&fp->f_vnread_flags, SLEEPQ_SLEEP, 0, 0);
776 sleepq_release(&fp->f_vnread_flags);
780 foffset_lock(struct file *fp, int flags)
785 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
787 mtxp = mtx_pool_find(mtxpool_sleep, fp);
789 if ((flags & FOF_NOLOCK) == 0) {
790 while (fp->f_vnread_flags & FOFFSET_LOCKED) {
791 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING;
792 msleep(&fp->f_vnread_flags, mtxp, PUSER -1,
795 fp->f_vnread_flags |= FOFFSET_LOCKED;
803 foffset_unlock(struct file *fp, off_t val, int flags)
807 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
809 mtxp = mtx_pool_find(mtxpool_sleep, fp);
811 if ((flags & FOF_NOUPDATE) == 0)
813 if ((flags & FOF_NEXTOFF_R) != 0)
814 fp->f_nextoff[UIO_READ] = val;
815 if ((flags & FOF_NEXTOFF_W) != 0)
816 fp->f_nextoff[UIO_WRITE] = val;
817 if ((flags & FOF_NOLOCK) == 0) {
818 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0,
819 ("Lost FOFFSET_LOCKED"));
820 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING)
821 wakeup(&fp->f_vnread_flags);
822 fp->f_vnread_flags = 0;
829 foffset_lock_uio(struct file *fp, struct uio *uio, int flags)
832 if ((flags & FOF_OFFSET) == 0)
833 uio->uio_offset = foffset_lock(fp, flags);
837 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags)
840 if ((flags & FOF_OFFSET) == 0)
841 foffset_unlock(fp, uio->uio_offset, flags);
845 get_advice(struct file *fp, struct uio *uio)
850 ret = POSIX_FADV_NORMAL;
851 if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG)
854 mtxp = mtx_pool_find(mtxpool_sleep, fp);
856 if (fp->f_advice != NULL &&
857 uio->uio_offset >= fp->f_advice->fa_start &&
858 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end)
859 ret = fp->f_advice->fa_advice;
865 vn_read_from_obj(struct vnode *vp, struct uio *uio)
868 vm_page_t ma[io_hold_cnt + 2];
874 MPASS(uio->uio_resid <= ptoa(io_hold_cnt + 2));
876 MPASS(obj->type == OBJT_VNODE);
879 * Depends on type stability of vm_objects.
881 vm_object_pip_add(obj, 1);
882 if ((obj->flags & OBJ_DEAD) != 0) {
884 * Note that object might be already reused from the
885 * vnode, and the OBJ_DEAD flag cleared. This is fine,
886 * we recheck for DOOMED vnode state after all pages
887 * are busied, and retract then.
889 * But we check for OBJ_DEAD to ensure that we do not
890 * busy pages while vm_object_terminate_pages()
891 * processes the queue.
897 resid = uio->uio_resid;
898 off = uio->uio_offset;
899 for (i = 0; resid > 0; i++) {
900 MPASS(i < io_hold_cnt + 2);
901 ma[i] = vm_page_grab_unlocked(obj, atop(off),
902 VM_ALLOC_NOCREAT | VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY |
908 * Skip invalid pages. Valid mask can be partial only
909 * at EOF, and we clip later.
911 if (vm_page_none_valid(ma[i])) {
912 vm_page_sunbusy(ma[i]);
925 * Check VIRF_DOOMED after we busied our pages. Since
926 * vgonel() terminates the vnode' vm_object, it cannot
927 * process past pages busied by us.
929 if (VN_IS_DOOMED(vp)) {
934 resid = PAGE_SIZE - (uio->uio_offset & PAGE_MASK) + ptoa(i - 1);
935 if (resid > uio->uio_resid)
936 resid = uio->uio_resid;
939 * Unlocked read of vnp_size is safe because truncation cannot
940 * pass busied page. But we load vnp_size into a local
941 * variable so that possible concurrent extension does not
944 #if defined(__powerpc__) && !defined(__powerpc64__)
945 vsz = obj->un_pager.vnp.vnp_size;
947 vsz = atomic_load_64(&obj->un_pager.vnp.vnp_size);
949 if (uio->uio_offset + resid > vsz)
950 resid = vsz - uio->uio_offset;
952 error = vn_io_fault_pgmove(ma, uio->uio_offset & PAGE_MASK, resid, uio);
955 for (j = 0; j < i; j++) {
957 vm_page_reference(ma[j]);
958 vm_page_sunbusy(ma[j]);
961 vm_object_pip_wakeup(obj);
964 return (uio->uio_resid == 0 ? 0 : EJUSTRETURN);
968 * File table vnode read routine.
971 vn_read(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
979 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
981 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
984 if (fp->f_flag & FNONBLOCK)
986 if (fp->f_flag & O_DIRECT)
990 * Try to read from page cache. VIRF_DOOMED check is racy but
991 * allows us to avoid unneeded work outright.
993 if (vn_io_pgcache_read_enable && !mac_vnode_check_read_enabled() &&
994 (vp->v_irflag & (VIRF_DOOMED | VIRF_PGREAD)) == VIRF_PGREAD) {
995 error = VOP_READ_PGCACHE(vp, uio, ioflag, fp->f_cred);
997 fp->f_nextoff[UIO_READ] = uio->uio_offset;
1000 if (error != EJUSTRETURN)
1004 advice = get_advice(fp, uio);
1005 vn_lock(vp, LK_SHARED | LK_RETRY);
1008 case POSIX_FADV_NORMAL:
1009 case POSIX_FADV_SEQUENTIAL:
1010 case POSIX_FADV_NOREUSE:
1011 ioflag |= sequential_heuristic(uio, fp);
1013 case POSIX_FADV_RANDOM:
1014 /* Disable read-ahead for random I/O. */
1017 orig_offset = uio->uio_offset;
1020 error = mac_vnode_check_read(active_cred, fp->f_cred, vp);
1023 error = VOP_READ(vp, uio, ioflag, fp->f_cred);
1024 fp->f_nextoff[UIO_READ] = uio->uio_offset;
1026 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
1027 orig_offset != uio->uio_offset)
1029 * Use POSIX_FADV_DONTNEED to flush pages and buffers
1030 * for the backing file after a POSIX_FADV_NOREUSE
1033 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
1034 POSIX_FADV_DONTNEED);
1039 * File table vnode write routine.
1042 vn_write(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
1048 int error, ioflag, lock_flags;
1051 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
1053 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
1055 if (vp->v_type == VREG)
1058 if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
1059 ioflag |= IO_APPEND;
1060 if (fp->f_flag & FNONBLOCK)
1061 ioflag |= IO_NDELAY;
1062 if (fp->f_flag & O_DIRECT)
1063 ioflag |= IO_DIRECT;
1064 if ((fp->f_flag & O_FSYNC) ||
1065 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
1068 if (vp->v_type != VCHR &&
1069 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
1072 advice = get_advice(fp, uio);
1074 if (MNT_SHARED_WRITES(mp) ||
1075 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) {
1076 lock_flags = LK_SHARED;
1078 lock_flags = LK_EXCLUSIVE;
1081 vn_lock(vp, lock_flags | LK_RETRY);
1083 case POSIX_FADV_NORMAL:
1084 case POSIX_FADV_SEQUENTIAL:
1085 case POSIX_FADV_NOREUSE:
1086 ioflag |= sequential_heuristic(uio, fp);
1088 case POSIX_FADV_RANDOM:
1089 /* XXX: Is this correct? */
1092 orig_offset = uio->uio_offset;
1095 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
1098 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred);
1099 fp->f_nextoff[UIO_WRITE] = uio->uio_offset;
1101 if (vp->v_type != VCHR)
1102 vn_finished_write(mp);
1103 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
1104 orig_offset != uio->uio_offset)
1106 * Use POSIX_FADV_DONTNEED to flush pages and buffers
1107 * for the backing file after a POSIX_FADV_NOREUSE
1110 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
1111 POSIX_FADV_DONTNEED);
1117 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to
1118 * prevent the following deadlock:
1120 * Assume that the thread A reads from the vnode vp1 into userspace
1121 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is
1122 * currently not resident, then system ends up with the call chain
1123 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] ->
1124 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2)
1125 * which establishes lock order vp1->vn_lock, then vp2->vn_lock.
1126 * If, at the same time, thread B reads from vnode vp2 into buffer buf2
1127 * backed by the pages of vnode vp1, and some page in buf2 is not
1128 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock.
1130 * To prevent the lock order reversal and deadlock, vn_io_fault() does
1131 * not allow page faults to happen during VOP_READ() or VOP_WRITE().
1132 * Instead, it first tries to do the whole range i/o with pagefaults
1133 * disabled. If all pages in the i/o buffer are resident and mapped,
1134 * VOP will succeed (ignoring the genuine filesystem errors).
1135 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do
1136 * i/o in chunks, with all pages in the chunk prefaulted and held
1137 * using vm_fault_quick_hold_pages().
1139 * Filesystems using this deadlock avoidance scheme should use the
1140 * array of the held pages from uio, saved in the curthread->td_ma,
1141 * instead of doing uiomove(). A helper function
1142 * vn_io_fault_uiomove() converts uiomove request into
1143 * uiomove_fromphys() over td_ma array.
1145 * Since vnode locks do not cover the whole i/o anymore, rangelocks
1146 * make the current i/o request atomic with respect to other i/os and
1151 * Decode vn_io_fault_args and perform the corresponding i/o.
1154 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio,
1160 save = vm_fault_disable_pagefaults();
1161 switch (args->kind) {
1162 case VN_IO_FAULT_FOP:
1163 error = (args->args.fop_args.doio)(args->args.fop_args.fp,
1164 uio, args->cred, args->flags, td);
1166 case VN_IO_FAULT_VOP:
1167 if (uio->uio_rw == UIO_READ) {
1168 error = VOP_READ(args->args.vop_args.vp, uio,
1169 args->flags, args->cred);
1170 } else if (uio->uio_rw == UIO_WRITE) {
1171 error = VOP_WRITE(args->args.vop_args.vp, uio,
1172 args->flags, args->cred);
1176 panic("vn_io_fault_doio: unknown kind of io %d %d",
1177 args->kind, uio->uio_rw);
1179 vm_fault_enable_pagefaults(save);
1184 vn_io_fault_touch(char *base, const struct uio *uio)
1189 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1))
1195 vn_io_fault_prefault_user(const struct uio *uio)
1198 const struct iovec *iov;
1203 KASSERT(uio->uio_segflg == UIO_USERSPACE,
1204 ("vn_io_fault_prefault userspace"));
1208 resid = uio->uio_resid;
1209 base = iov->iov_base;
1212 error = vn_io_fault_touch(base, uio);
1215 if (len < PAGE_SIZE) {
1217 error = vn_io_fault_touch(base + len - 1, uio);
1222 if (++i >= uio->uio_iovcnt)
1224 iov = uio->uio_iov + i;
1225 base = iov->iov_base;
1237 * Common code for vn_io_fault(), agnostic to the kind of i/o request.
1238 * Uses vn_io_fault_doio() to make the call to an actual i/o function.
1239 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request
1240 * into args and call vn_io_fault1() to handle faults during the user
1241 * mode buffer accesses.
1244 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args,
1247 vm_page_t ma[io_hold_cnt + 2];
1248 struct uio *uio_clone, short_uio;
1249 struct iovec short_iovec[1];
1250 vm_page_t *prev_td_ma;
1252 vm_offset_t addr, end;
1255 int error, cnt, saveheld, prev_td_ma_cnt;
1257 if (vn_io_fault_prefault) {
1258 error = vn_io_fault_prefault_user(uio);
1260 return (error); /* Or ignore ? */
1263 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ;
1266 * The UFS follows IO_UNIT directive and replays back both
1267 * uio_offset and uio_resid if an error is encountered during the
1268 * operation. But, since the iovec may be already advanced,
1269 * uio is still in an inconsistent state.
1271 * Cache a copy of the original uio, which is advanced to the redo
1272 * point using UIO_NOCOPY below.
1274 uio_clone = cloneuio(uio);
1275 resid = uio->uio_resid;
1277 short_uio.uio_segflg = UIO_USERSPACE;
1278 short_uio.uio_rw = uio->uio_rw;
1279 short_uio.uio_td = uio->uio_td;
1281 error = vn_io_fault_doio(args, uio, td);
1282 if (error != EFAULT)
1285 atomic_add_long(&vn_io_faults_cnt, 1);
1286 uio_clone->uio_segflg = UIO_NOCOPY;
1287 uiomove(NULL, resid - uio->uio_resid, uio_clone);
1288 uio_clone->uio_segflg = uio->uio_segflg;
1290 saveheld = curthread_pflags_set(TDP_UIOHELD);
1291 prev_td_ma = td->td_ma;
1292 prev_td_ma_cnt = td->td_ma_cnt;
1294 while (uio_clone->uio_resid != 0) {
1295 len = uio_clone->uio_iov->iov_len;
1297 KASSERT(uio_clone->uio_iovcnt >= 1,
1298 ("iovcnt underflow"));
1299 uio_clone->uio_iov++;
1300 uio_clone->uio_iovcnt--;
1303 if (len > ptoa(io_hold_cnt))
1304 len = ptoa(io_hold_cnt);
1305 addr = (uintptr_t)uio_clone->uio_iov->iov_base;
1306 end = round_page(addr + len);
1311 cnt = atop(end - trunc_page(addr));
1313 * A perfectly misaligned address and length could cause
1314 * both the start and the end of the chunk to use partial
1315 * page. +2 accounts for such a situation.
1317 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map,
1318 addr, len, prot, ma, io_hold_cnt + 2);
1323 short_uio.uio_iov = &short_iovec[0];
1324 short_iovec[0].iov_base = (void *)addr;
1325 short_uio.uio_iovcnt = 1;
1326 short_uio.uio_resid = short_iovec[0].iov_len = len;
1327 short_uio.uio_offset = uio_clone->uio_offset;
1329 td->td_ma_cnt = cnt;
1331 error = vn_io_fault_doio(args, &short_uio, td);
1332 vm_page_unhold_pages(ma, cnt);
1333 adv = len - short_uio.uio_resid;
1335 uio_clone->uio_iov->iov_base =
1336 (char *)uio_clone->uio_iov->iov_base + adv;
1337 uio_clone->uio_iov->iov_len -= adv;
1338 uio_clone->uio_resid -= adv;
1339 uio_clone->uio_offset += adv;
1341 uio->uio_resid -= adv;
1342 uio->uio_offset += adv;
1344 if (error != 0 || adv == 0)
1347 td->td_ma = prev_td_ma;
1348 td->td_ma_cnt = prev_td_ma_cnt;
1349 curthread_pflags_restore(saveheld);
1351 free(uio_clone, M_IOV);
1356 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred,
1357 int flags, struct thread *td)
1362 struct vn_io_fault_args args;
1365 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write;
1369 * The ability to read(2) on a directory has historically been
1370 * allowed for all users, but this can and has been the source of
1371 * at least one security issue in the past. As such, it is now hidden
1372 * away behind a sysctl for those that actually need it to use it, and
1373 * restricted to root when it's turned on to make it relatively safe to
1374 * leave on for longer sessions of need.
1376 if (vp->v_type == VDIR) {
1377 KASSERT(uio->uio_rw == UIO_READ,
1378 ("illegal write attempted on a directory"));
1379 if (!vfs_allow_read_dir)
1381 if ((error = priv_check(td, PRIV_VFS_READ_DIR)) != 0)
1385 foffset_lock_uio(fp, uio, flags);
1386 if (do_vn_io_fault(vp, uio)) {
1387 args.kind = VN_IO_FAULT_FOP;
1388 args.args.fop_args.fp = fp;
1389 args.args.fop_args.doio = doio;
1390 args.cred = active_cred;
1391 args.flags = flags | FOF_OFFSET;
1392 if (uio->uio_rw == UIO_READ) {
1393 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset,
1394 uio->uio_offset + uio->uio_resid);
1395 } else if ((fp->f_flag & O_APPEND) != 0 ||
1396 (flags & FOF_OFFSET) == 0) {
1397 /* For appenders, punt and lock the whole range. */
1398 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1400 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset,
1401 uio->uio_offset + uio->uio_resid);
1403 error = vn_io_fault1(vp, uio, &args, td);
1404 vn_rangelock_unlock(vp, rl_cookie);
1406 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td);
1408 foffset_unlock_uio(fp, uio, flags);
1413 * Helper function to perform the requested uiomove operation using
1414 * the held pages for io->uio_iov[0].iov_base buffer instead of
1415 * copyin/copyout. Access to the pages with uiomove_fromphys()
1416 * instead of iov_base prevents page faults that could occur due to
1417 * pmap_collect() invalidating the mapping created by
1418 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or
1419 * object cleanup revoking the write access from page mappings.
1421 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove()
1422 * instead of plain uiomove().
1425 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio)
1427 struct uio transp_uio;
1428 struct iovec transp_iov[1];
1434 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1435 uio->uio_segflg != UIO_USERSPACE)
1436 return (uiomove(data, xfersize, uio));
1438 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1439 transp_iov[0].iov_base = data;
1440 transp_uio.uio_iov = &transp_iov[0];
1441 transp_uio.uio_iovcnt = 1;
1442 if (xfersize > uio->uio_resid)
1443 xfersize = uio->uio_resid;
1444 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize;
1445 transp_uio.uio_offset = 0;
1446 transp_uio.uio_segflg = UIO_SYSSPACE;
1448 * Since transp_iov points to data, and td_ma page array
1449 * corresponds to original uio->uio_iov, we need to invert the
1450 * direction of the i/o operation as passed to
1451 * uiomove_fromphys().
1453 switch (uio->uio_rw) {
1455 transp_uio.uio_rw = UIO_READ;
1458 transp_uio.uio_rw = UIO_WRITE;
1461 transp_uio.uio_td = uio->uio_td;
1462 error = uiomove_fromphys(td->td_ma,
1463 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK,
1464 xfersize, &transp_uio);
1465 adv = xfersize - transp_uio.uio_resid;
1467 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) -
1468 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT);
1470 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1472 td->td_ma_cnt -= pgadv;
1473 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv;
1474 uio->uio_iov->iov_len -= adv;
1475 uio->uio_resid -= adv;
1476 uio->uio_offset += adv;
1481 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize,
1485 vm_offset_t iov_base;
1489 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1490 uio->uio_segflg != UIO_USERSPACE)
1491 return (uiomove_fromphys(ma, offset, xfersize, uio));
1493 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1494 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize;
1495 iov_base = (vm_offset_t)uio->uio_iov->iov_base;
1496 switch (uio->uio_rw) {
1498 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma,
1502 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK,
1506 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT);
1508 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1510 td->td_ma_cnt -= pgadv;
1511 uio->uio_iov->iov_base = (char *)(iov_base + cnt);
1512 uio->uio_iov->iov_len -= cnt;
1513 uio->uio_resid -= cnt;
1514 uio->uio_offset += cnt;
1519 * File table truncate routine.
1522 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred,
1534 * Lock the whole range for truncation. Otherwise split i/o
1535 * might happen partly before and partly after the truncation.
1537 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1538 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
1541 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1542 AUDIT_ARG_VNODE1(vp);
1543 if (vp->v_type == VDIR) {
1548 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
1552 error = vn_truncate_locked(vp, length, (fp->f_flag & O_FSYNC) != 0,
1556 vn_finished_write(mp);
1558 vn_rangelock_unlock(vp, rl_cookie);
1559 if (error == ERELOOKUP)
1565 * Truncate a file that is already locked.
1568 vn_truncate_locked(struct vnode *vp, off_t length, bool sync,
1574 error = VOP_ADD_WRITECOUNT(vp, 1);
1577 vattr.va_size = length;
1579 vattr.va_vaflags |= VA_SYNC;
1580 error = VOP_SETATTR(vp, &vattr, cred);
1581 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
1587 * File table vnode stat routine.
1590 vn_statfile(struct file *fp, struct stat *sb, struct ucred *active_cred,
1593 struct vnode *vp = fp->f_vnode;
1596 vn_lock(vp, LK_SHARED | LK_RETRY);
1597 error = VOP_STAT(vp, sb, active_cred, fp->f_cred, td);
1604 * File table vnode ioctl routine.
1607 vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
1612 struct fiobmap2_arg *bmarg;
1616 switch (vp->v_type) {
1621 vn_lock(vp, LK_SHARED | LK_RETRY);
1622 error = VOP_GETATTR(vp, &vattr, active_cred);
1625 *(int *)data = vattr.va_size - fp->f_offset;
1628 bmarg = (struct fiobmap2_arg *)data;
1629 vn_lock(vp, LK_SHARED | LK_RETRY);
1631 error = mac_vnode_check_read(active_cred, fp->f_cred,
1635 error = VOP_BMAP(vp, bmarg->bn, NULL,
1636 &bmarg->bn, &bmarg->runp, &bmarg->runb);
1643 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1648 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1656 * File table vnode poll routine.
1659 vn_poll(struct file *fp, int events, struct ucred *active_cred,
1666 #if defined(MAC) || defined(AUDIT)
1667 if (AUDITING_TD(td) || mac_vnode_check_poll_enabled()) {
1668 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1669 AUDIT_ARG_VNODE1(vp);
1670 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp);
1676 error = VOP_POLL(vp, events, fp->f_cred, td);
1681 * Acquire the requested lock and then check for validity. LK_RETRY
1682 * permits vn_lock to return doomed vnodes.
1684 static int __noinline
1685 _vn_lock_fallback(struct vnode *vp, int flags, const char *file, int line,
1689 KASSERT((flags & LK_RETRY) == 0 || error == 0,
1690 ("vn_lock: error %d incompatible with flags %#x", error, flags));
1693 VNASSERT(VN_IS_DOOMED(vp), vp, ("vnode not doomed"));
1695 if ((flags & LK_RETRY) == 0) {
1706 * Nothing to do if we got the lock.
1712 * Interlock was dropped by the call in _vn_lock.
1714 flags &= ~LK_INTERLOCK;
1716 error = VOP_LOCK1(vp, flags, file, line);
1717 } while (error != 0);
1722 _vn_lock(struct vnode *vp, int flags, const char *file, int line)
1726 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
1727 ("vn_lock: no locktype (%d passed)", flags));
1728 VNPASS(vp->v_holdcnt > 0, vp);
1729 error = VOP_LOCK1(vp, flags, file, line);
1730 if (__predict_false(error != 0 || VN_IS_DOOMED(vp)))
1731 return (_vn_lock_fallback(vp, flags, file, line, error));
1736 * File table vnode close routine.
1739 vn_closefile(struct file *fp, struct thread *td)
1747 fp->f_ops = &badfileops;
1748 ref= (fp->f_flag & FHASLOCK) != 0 && fp->f_type == DTYPE_VNODE;
1750 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref);
1752 if (__predict_false(ref)) {
1753 lf.l_whence = SEEK_SET;
1756 lf.l_type = F_UNLCK;
1757 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK);
1764 * Preparing to start a filesystem write operation. If the operation is
1765 * permitted, then we bump the count of operations in progress and
1766 * proceed. If a suspend request is in progress, we wait until the
1767 * suspension is over, and then proceed.
1770 vn_start_write_refed(struct mount *mp, int flags, bool mplocked)
1772 struct mount_pcpu *mpcpu;
1775 if (__predict_true(!mplocked) && (flags & V_XSLEEP) == 0 &&
1776 vfs_op_thread_enter(mp, mpcpu)) {
1777 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0);
1778 vfs_mp_count_add_pcpu(mpcpu, writeopcount, 1);
1779 vfs_op_thread_exit(mp, mpcpu);
1784 mtx_assert(MNT_MTX(mp), MA_OWNED);
1791 * Check on status of suspension.
1793 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 ||
1794 mp->mnt_susp_owner != curthread) {
1795 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ?
1796 (flags & PCATCH) : 0) | (PUSER - 1);
1797 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1798 if (flags & V_NOWAIT) {
1799 error = EWOULDBLOCK;
1802 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags,
1808 if (flags & V_XSLEEP)
1810 mp->mnt_writeopcount++;
1812 if (error != 0 || (flags & V_XSLEEP) != 0)
1819 vn_start_write(struct vnode *vp, struct mount **mpp, int flags)
1824 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1825 ("V_MNTREF requires mp"));
1829 * If a vnode is provided, get and return the mount point that
1830 * to which it will write.
1833 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1835 if (error != EOPNOTSUPP)
1840 if ((mp = *mpp) == NULL)
1844 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1846 * As long as a vnode is not provided we need to acquire a
1847 * refcount for the provided mountpoint too, in order to
1848 * emulate a vfs_ref().
1850 if (vp == NULL && (flags & V_MNTREF) == 0)
1853 return (vn_start_write_refed(mp, flags, false));
1857 * Secondary suspension. Used by operations such as vop_inactive
1858 * routines that are needed by the higher level functions. These
1859 * are allowed to proceed until all the higher level functions have
1860 * completed (indicated by mnt_writeopcount dropping to zero). At that
1861 * time, these operations are halted until the suspension is over.
1864 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags)
1869 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1870 ("V_MNTREF requires mp"));
1874 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1876 if (error != EOPNOTSUPP)
1882 * If we are not suspended or have not yet reached suspended
1883 * mode, then let the operation proceed.
1885 if ((mp = *mpp) == NULL)
1889 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1891 * As long as a vnode is not provided we need to acquire a
1892 * refcount for the provided mountpoint too, in order to
1893 * emulate a vfs_ref().
1896 if (vp == NULL && (flags & V_MNTREF) == 0)
1898 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) {
1899 mp->mnt_secondary_writes++;
1900 mp->mnt_secondary_accwrites++;
1904 if (flags & V_NOWAIT) {
1907 return (EWOULDBLOCK);
1910 * Wait for the suspension to finish.
1912 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP |
1913 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0),
1922 * Filesystem write operation has completed. If we are suspending and this
1923 * operation is the last one, notify the suspender that the suspension is
1927 vn_finished_write(struct mount *mp)
1929 struct mount_pcpu *mpcpu;
1935 if (vfs_op_thread_enter(mp, mpcpu)) {
1936 vfs_mp_count_sub_pcpu(mpcpu, writeopcount, 1);
1937 vfs_mp_count_sub_pcpu(mpcpu, ref, 1);
1938 vfs_op_thread_exit(mp, mpcpu);
1943 vfs_assert_mount_counters(mp);
1945 c = --mp->mnt_writeopcount;
1946 if (mp->mnt_vfs_ops == 0) {
1947 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0);
1952 vfs_dump_mount_counters(mp);
1953 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && c == 0)
1954 wakeup(&mp->mnt_writeopcount);
1959 * Filesystem secondary write operation has completed. If we are
1960 * suspending and this operation is the last one, notify the suspender
1961 * that the suspension is now in effect.
1964 vn_finished_secondary_write(struct mount *mp)
1970 mp->mnt_secondary_writes--;
1971 if (mp->mnt_secondary_writes < 0)
1972 panic("vn_finished_secondary_write: neg cnt");
1973 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
1974 mp->mnt_secondary_writes <= 0)
1975 wakeup(&mp->mnt_secondary_writes);
1980 * Request a filesystem to suspend write operations.
1983 vfs_write_suspend(struct mount *mp, int flags)
1990 vfs_assert_mount_counters(mp);
1991 if (mp->mnt_susp_owner == curthread) {
1992 vfs_op_exit_locked(mp);
1996 while (mp->mnt_kern_flag & MNTK_SUSPEND)
1997 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0);
2000 * Unmount holds a write reference on the mount point. If we
2001 * own busy reference and drain for writers, we deadlock with
2002 * the reference draining in the unmount path. Callers of
2003 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if
2004 * vfs_busy() reference is owned and caller is not in the
2007 if ((flags & VS_SKIP_UNMOUNT) != 0 &&
2008 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) {
2009 vfs_op_exit_locked(mp);
2014 mp->mnt_kern_flag |= MNTK_SUSPEND;
2015 mp->mnt_susp_owner = curthread;
2016 if (mp->mnt_writeopcount > 0)
2017 (void) msleep(&mp->mnt_writeopcount,
2018 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0);
2021 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) {
2022 vfs_write_resume(mp, 0);
2023 /* vfs_write_resume does vfs_op_exit() for us */
2029 * Request a filesystem to resume write operations.
2032 vfs_write_resume(struct mount *mp, int flags)
2036 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
2037 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner"));
2038 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 |
2040 mp->mnt_susp_owner = NULL;
2041 wakeup(&mp->mnt_writeopcount);
2042 wakeup(&mp->mnt_flag);
2043 curthread->td_pflags &= ~TDP_IGNSUSP;
2044 if ((flags & VR_START_WRITE) != 0) {
2046 mp->mnt_writeopcount++;
2049 if ((flags & VR_NO_SUSPCLR) == 0)
2052 } else if ((flags & VR_START_WRITE) != 0) {
2054 vn_start_write_refed(mp, 0, true);
2061 * Helper loop around vfs_write_suspend() for filesystem unmount VFS
2065 vfs_write_suspend_umnt(struct mount *mp)
2069 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0,
2070 ("vfs_write_suspend_umnt: recursed"));
2072 /* dounmount() already called vn_start_write(). */
2074 vn_finished_write(mp);
2075 error = vfs_write_suspend(mp, 0);
2077 vn_start_write(NULL, &mp, V_WAIT);
2081 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0)
2084 vn_start_write(NULL, &mp, V_WAIT);
2086 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2);
2087 wakeup(&mp->mnt_flag);
2089 curthread->td_pflags |= TDP_IGNSUSP;
2094 * Implement kqueues for files by translating it to vnode operation.
2097 vn_kqfilter(struct file *fp, struct knote *kn)
2100 return (VOP_KQFILTER(fp->f_vnode, kn));
2104 * Simplified in-kernel wrapper calls for extended attribute access.
2105 * Both calls pass in a NULL credential, authorizing as "kernel" access.
2106 * Set IO_NODELOCKED in ioflg if the vnode is already locked.
2109 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace,
2110 const char *attrname, int *buflen, char *buf, struct thread *td)
2116 iov.iov_len = *buflen;
2119 auio.uio_iov = &iov;
2120 auio.uio_iovcnt = 1;
2121 auio.uio_rw = UIO_READ;
2122 auio.uio_segflg = UIO_SYSSPACE;
2124 auio.uio_offset = 0;
2125 auio.uio_resid = *buflen;
2127 if ((ioflg & IO_NODELOCKED) == 0)
2128 vn_lock(vp, LK_SHARED | LK_RETRY);
2130 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2132 /* authorize attribute retrieval as kernel */
2133 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL,
2136 if ((ioflg & IO_NODELOCKED) == 0)
2140 *buflen = *buflen - auio.uio_resid;
2147 * XXX failure mode if partially written?
2150 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace,
2151 const char *attrname, int buflen, char *buf, struct thread *td)
2158 iov.iov_len = buflen;
2161 auio.uio_iov = &iov;
2162 auio.uio_iovcnt = 1;
2163 auio.uio_rw = UIO_WRITE;
2164 auio.uio_segflg = UIO_SYSSPACE;
2166 auio.uio_offset = 0;
2167 auio.uio_resid = buflen;
2169 if ((ioflg & IO_NODELOCKED) == 0) {
2170 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2172 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2175 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2177 /* authorize attribute setting as kernel */
2178 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td);
2180 if ((ioflg & IO_NODELOCKED) == 0) {
2181 vn_finished_write(mp);
2189 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace,
2190 const char *attrname, struct thread *td)
2195 if ((ioflg & IO_NODELOCKED) == 0) {
2196 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2198 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2201 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2203 /* authorize attribute removal as kernel */
2204 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td);
2205 if (error == EOPNOTSUPP)
2206 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL,
2209 if ((ioflg & IO_NODELOCKED) == 0) {
2210 vn_finished_write(mp);
2218 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags,
2222 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp));
2226 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp)
2229 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino,
2234 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg,
2235 int lkflags, struct vnode **rvp)
2240 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get");
2242 ltype = VOP_ISLOCKED(vp);
2243 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED,
2244 ("vn_vget_ino: vp not locked"));
2245 error = vfs_busy(mp, MBF_NOWAIT);
2249 error = vfs_busy(mp, 0);
2250 vn_lock(vp, ltype | LK_RETRY);
2254 if (VN_IS_DOOMED(vp)) {
2260 error = alloc(mp, alloc_arg, lkflags, rvp);
2262 if (error != 0 || *rvp != vp)
2263 vn_lock(vp, ltype | LK_RETRY);
2264 if (VN_IS_DOOMED(vp)) {
2277 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio,
2281 if (vp->v_type != VREG || td == NULL)
2283 if ((uoff_t)uio->uio_offset + uio->uio_resid >
2284 lim_cur(td, RLIMIT_FSIZE)) {
2285 PROC_LOCK(td->td_proc);
2286 kern_psignal(td->td_proc, SIGXFSZ);
2287 PROC_UNLOCK(td->td_proc);
2294 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
2301 vn_lock(vp, LK_SHARED | LK_RETRY);
2302 AUDIT_ARG_VNODE1(vp);
2305 return (setfmode(td, active_cred, vp, mode));
2309 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
2316 vn_lock(vp, LK_SHARED | LK_RETRY);
2317 AUDIT_ARG_VNODE1(vp);
2320 return (setfown(td, active_cred, vp, uid, gid));
2324 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end)
2328 if ((object = vp->v_object) == NULL)
2330 VM_OBJECT_WLOCK(object);
2331 vm_object_page_remove(object, start, end, 0);
2332 VM_OBJECT_WUNLOCK(object);
2336 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred)
2344 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
2345 ("Wrong command %lu", cmd));
2347 if (vn_lock(vp, LK_SHARED) != 0)
2349 if (vp->v_type != VREG) {
2353 error = VOP_GETATTR(vp, &va, cred);
2357 if (noff >= va.va_size) {
2361 bsize = vp->v_mount->mnt_stat.f_iosize;
2362 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize -
2364 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL);
2365 if (error == EOPNOTSUPP) {
2369 if ((bnp == -1 && cmd == FIOSEEKHOLE) ||
2370 (bnp != -1 && cmd == FIOSEEKDATA)) {
2377 if (noff > va.va_size)
2379 /* noff == va.va_size. There is an implicit hole at the end of file. */
2380 if (cmd == FIOSEEKDATA)
2390 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td)
2395 off_t foffset, size;
2398 cred = td->td_ucred;
2400 foffset = foffset_lock(fp, 0);
2401 noneg = (vp->v_type != VCHR);
2407 (offset > 0 && foffset > OFF_MAX - offset))) {
2414 vn_lock(vp, LK_SHARED | LK_RETRY);
2415 error = VOP_GETATTR(vp, &vattr, cred);
2421 * If the file references a disk device, then fetch
2422 * the media size and use that to determine the ending
2425 if (vattr.va_size == 0 && vp->v_type == VCHR &&
2426 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0)
2427 vattr.va_size = size;
2429 (vattr.va_size > OFF_MAX ||
2430 (offset > 0 && vattr.va_size > OFF_MAX - offset))) {
2434 offset += vattr.va_size;
2439 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td);
2440 if (error == ENOTTY)
2444 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td);
2445 if (error == ENOTTY)
2451 if (error == 0 && noneg && offset < 0)
2455 VFS_KNOTE_UNLOCKED(vp, 0);
2456 td->td_uretoff.tdu_off = offset;
2458 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0);
2463 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred,
2469 * Grant permission if the caller is the owner of the file, or
2470 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on
2471 * on the file. If the time pointer is null, then write
2472 * permission on the file is also sufficient.
2474 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes:
2475 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES
2476 * will be allowed to set the times [..] to the current
2479 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td);
2480 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0)
2481 error = VOP_ACCESS(vp, VWRITE, cred, td);
2486 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
2491 if (fp->f_type == DTYPE_FIFO)
2492 kif->kf_type = KF_TYPE_FIFO;
2494 kif->kf_type = KF_TYPE_VNODE;
2497 FILEDESC_SUNLOCK(fdp);
2498 error = vn_fill_kinfo_vnode(vp, kif);
2500 FILEDESC_SLOCK(fdp);
2505 vn_fill_junk(struct kinfo_file *kif)
2510 * Simulate vn_fullpath returning changing values for a given
2511 * vp during e.g. coredump.
2513 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1;
2514 olen = strlen(kif->kf_path);
2516 strcpy(&kif->kf_path[len - 1], "$");
2518 for (; olen < len; olen++)
2519 strcpy(&kif->kf_path[olen], "A");
2523 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif)
2526 char *fullpath, *freepath;
2529 kif->kf_un.kf_file.kf_file_type = vntype_to_kinfo(vp->v_type);
2532 error = vn_fullpath(vp, &fullpath, &freepath);
2534 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
2536 if (freepath != NULL)
2537 free(freepath, M_TEMP);
2539 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path,
2544 * Retrieve vnode attributes.
2546 va.va_fsid = VNOVAL;
2548 vn_lock(vp, LK_SHARED | LK_RETRY);
2549 error = VOP_GETATTR(vp, &va, curthread->td_ucred);
2553 if (va.va_fsid != VNOVAL)
2554 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid;
2556 kif->kf_un.kf_file.kf_file_fsid =
2557 vp->v_mount->mnt_stat.f_fsid.val[0];
2558 kif->kf_un.kf_file.kf_file_fsid_freebsd11 =
2559 kif->kf_un.kf_file.kf_file_fsid; /* truncate */
2560 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid;
2561 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode);
2562 kif->kf_un.kf_file.kf_file_size = va.va_size;
2563 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev;
2564 kif->kf_un.kf_file.kf_file_rdev_freebsd11 =
2565 kif->kf_un.kf_file.kf_file_rdev; /* truncate */
2570 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
2571 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
2575 struct pmckern_map_in pkm;
2581 boolean_t writecounted;
2584 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
2585 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
2587 * POSIX shared-memory objects are defined to have
2588 * kernel persistence, and are not defined to support
2589 * read(2)/write(2) -- or even open(2). Thus, we can
2590 * use MAP_ASYNC to trade on-disk coherence for speed.
2591 * The shm_open(3) library routine turns on the FPOSIXSHM
2592 * flag to request this behavior.
2594 if ((fp->f_flag & FPOSIXSHM) != 0)
2595 flags |= MAP_NOSYNC;
2600 * Ensure that file and memory protections are
2601 * compatible. Note that we only worry about
2602 * writability if mapping is shared; in this case,
2603 * current and max prot are dictated by the open file.
2604 * XXX use the vnode instead? Problem is: what
2605 * credentials do we use for determination? What if
2606 * proc does a setuid?
2609 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) {
2610 maxprot = VM_PROT_NONE;
2611 if ((prot & VM_PROT_EXECUTE) != 0)
2614 maxprot = VM_PROT_EXECUTE;
2615 if ((fp->f_flag & FREAD) != 0)
2616 maxprot |= VM_PROT_READ;
2617 else if ((prot & VM_PROT_READ) != 0)
2621 * If we are sharing potential changes via MAP_SHARED and we
2622 * are trying to get write permission although we opened it
2623 * without asking for it, bail out.
2625 if ((flags & MAP_SHARED) != 0) {
2626 if ((fp->f_flag & FWRITE) != 0)
2627 maxprot |= VM_PROT_WRITE;
2628 else if ((prot & VM_PROT_WRITE) != 0)
2631 maxprot |= VM_PROT_WRITE;
2632 cap_maxprot |= VM_PROT_WRITE;
2634 maxprot &= cap_maxprot;
2637 * For regular files and shared memory, POSIX requires that
2638 * the value of foff be a legitimate offset within the data
2639 * object. In particular, negative offsets are invalid.
2640 * Blocking negative offsets and overflows here avoids
2641 * possible wraparound or user-level access into reserved
2642 * ranges of the data object later. In contrast, POSIX does
2643 * not dictate how offsets are used by device drivers, so in
2644 * the case of a device mapping a negative offset is passed
2651 foff > OFF_MAX - size)
2654 writecounted = FALSE;
2655 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp,
2656 &foff, &object, &writecounted);
2659 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
2660 foff, writecounted, td);
2663 * If this mapping was accounted for in the vnode's
2664 * writecount, then undo that now.
2667 vm_pager_release_writecount(object, 0, size);
2668 vm_object_deallocate(object);
2671 /* Inform hwpmc(4) if an executable is being mapped. */
2672 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) {
2673 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) {
2675 pkm.pm_address = (uintptr_t) *addr;
2676 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_MMAP, (void *) &pkm);
2684 vn_fsid(struct vnode *vp, struct vattr *va)
2688 f = &vp->v_mount->mnt_stat.f_fsid;
2689 va->va_fsid = (uint32_t)f->val[1];
2690 va->va_fsid <<= sizeof(f->val[1]) * NBBY;
2691 va->va_fsid += (uint32_t)f->val[0];
2695 vn_fsync_buf(struct vnode *vp, int waitfor)
2697 struct buf *bp, *nbp;
2700 int error, maxretry;
2703 maxretry = 10000; /* large, arbitrarily chosen */
2705 if (vp->v_type == VCHR) {
2707 mp = vp->v_rdev->si_mountpt;
2714 * MARK/SCAN initialization to avoid infinite loops.
2716 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) {
2717 bp->b_vflags &= ~BV_SCANNED;
2722 * Flush all dirty buffers associated with a vnode.
2725 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
2726 if ((bp->b_vflags & BV_SCANNED) != 0)
2728 bp->b_vflags |= BV_SCANNED;
2729 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) {
2730 if (waitfor != MNT_WAIT)
2733 LK_EXCLUSIVE | LK_INTERLOCK | LK_SLEEPFAIL,
2734 BO_LOCKPTR(bo)) != 0) {
2741 KASSERT(bp->b_bufobj == bo,
2742 ("bp %p wrong b_bufobj %p should be %p",
2743 bp, bp->b_bufobj, bo));
2744 if ((bp->b_flags & B_DELWRI) == 0)
2745 panic("fsync: not dirty");
2746 if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) {
2752 if (maxretry < 1000)
2753 pause("dirty", hz < 1000 ? 1 : hz / 1000);
2759 * If synchronous the caller expects us to completely resolve all
2760 * dirty buffers in the system. Wait for in-progress I/O to
2761 * complete (which could include background bitmap writes), then
2762 * retry if dirty blocks still exist.
2764 if (waitfor == MNT_WAIT) {
2765 bufobj_wwait(bo, 0, 0);
2766 if (bo->bo_dirty.bv_cnt > 0) {
2768 * If we are unable to write any of these buffers
2769 * then we fail now rather than trying endlessly
2770 * to write them out.
2772 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs)
2773 if ((error = bp->b_error) != 0)
2775 if ((mp != NULL && mp->mnt_secondary_writes > 0) ||
2776 (error == 0 && --maxretry >= 0))
2784 vn_printf(vp, "fsync: giving up on dirty (error = %d) ", error);
2790 * Copies a byte range from invp to outvp. Calls VOP_COPY_FILE_RANGE()
2791 * or vn_generic_copy_file_range() after rangelocking the byte ranges,
2792 * to do the actual copy.
2793 * vn_generic_copy_file_range() is factored out, so it can be called
2794 * from a VOP_COPY_FILE_RANGE() call as well, but handles vnodes from
2795 * different file systems.
2798 vn_copy_file_range(struct vnode *invp, off_t *inoffp, struct vnode *outvp,
2799 off_t *outoffp, size_t *lenp, unsigned int flags, struct ucred *incred,
2800 struct ucred *outcred, struct thread *fsize_td)
2807 *lenp = 0; /* For error returns. */
2810 /* Do some sanity checks on the arguments. */
2811 if (invp->v_type == VDIR || outvp->v_type == VDIR)
2813 else if (*inoffp < 0 || *outoffp < 0 ||
2814 invp->v_type != VREG || outvp->v_type != VREG)
2819 /* Ensure offset + len does not wrap around. */
2822 if (uval > INT64_MAX)
2823 len = INT64_MAX - *inoffp;
2826 if (uval > INT64_MAX)
2827 len = INT64_MAX - *outoffp;
2832 * If the two vnode are for the same file system, call
2833 * VOP_COPY_FILE_RANGE(), otherwise call vn_generic_copy_file_range()
2834 * which can handle copies across multiple file systems.
2837 if (invp->v_mount == outvp->v_mount)
2838 error = VOP_COPY_FILE_RANGE(invp, inoffp, outvp, outoffp,
2839 lenp, flags, incred, outcred, fsize_td);
2841 error = vn_generic_copy_file_range(invp, inoffp, outvp,
2842 outoffp, lenp, flags, incred, outcred, fsize_td);
2848 * Test len bytes of data starting at dat for all bytes == 0.
2849 * Return true if all bytes are zero, false otherwise.
2850 * Expects dat to be well aligned.
2853 mem_iszero(void *dat, int len)
2859 for (p = dat; len > 0; len -= sizeof(*p), p++) {
2860 if (len >= sizeof(*p)) {
2864 cp = (const char *)p;
2865 for (i = 0; i < len; i++, cp++)
2874 * Look for a hole in the output file and, if found, adjust *outoffp
2875 * and *xferp to skip past the hole.
2876 * *xferp is the entire hole length to be written and xfer2 is how many bytes
2877 * to be written as 0's upon return.
2880 vn_skip_hole(struct vnode *outvp, off_t xfer2, off_t *outoffp, off_t *xferp,
2881 off_t *dataoffp, off_t *holeoffp, struct ucred *cred)
2886 if (*holeoffp == 0 || *holeoffp <= *outoffp) {
2887 *dataoffp = *outoffp;
2888 error = VOP_IOCTL(outvp, FIOSEEKDATA, dataoffp, 0, cred,
2891 *holeoffp = *dataoffp;
2892 error = VOP_IOCTL(outvp, FIOSEEKHOLE, holeoffp, 0, cred,
2895 if (error != 0 || *holeoffp == *dataoffp) {
2897 * Since outvp is unlocked, it may be possible for
2898 * another thread to do a truncate(), lseek(), write()
2899 * creating a hole at startoff between the above
2900 * VOP_IOCTL() calls, if the other thread does not do
2902 * If that happens, *holeoffp == *dataoffp and finding
2903 * the hole has failed, so disable vn_skip_hole().
2905 *holeoffp = -1; /* Disable use of vn_skip_hole(). */
2908 KASSERT(*dataoffp >= *outoffp,
2909 ("vn_skip_hole: dataoff=%jd < outoff=%jd",
2910 (intmax_t)*dataoffp, (intmax_t)*outoffp));
2911 KASSERT(*holeoffp > *dataoffp,
2912 ("vn_skip_hole: holeoff=%jd <= dataoff=%jd",
2913 (intmax_t)*holeoffp, (intmax_t)*dataoffp));
2917 * If there is a hole before the data starts, advance *outoffp and
2918 * *xferp past the hole.
2920 if (*dataoffp > *outoffp) {
2921 delta = *dataoffp - *outoffp;
2922 if (delta >= *xferp) {
2923 /* Entire *xferp is a hole. */
2930 xfer2 = MIN(xfer2, *xferp);
2934 * If a hole starts before the end of this xfer2, reduce this xfer2 so
2935 * that the write ends at the start of the hole.
2936 * *holeoffp should always be greater than *outoffp, but for the
2937 * non-INVARIANTS case, check this to make sure xfer2 remains a sane
2940 if (*holeoffp > *outoffp && *holeoffp < *outoffp + xfer2)
2941 xfer2 = *holeoffp - *outoffp;
2946 * Write an xfer sized chunk to outvp in blksize blocks from dat.
2947 * dat is a maximum of blksize in length and can be written repeatedly in
2949 * If growfile == true, just grow the file via vn_truncate_locked() instead
2950 * of doing actual writes.
2951 * If checkhole == true, a hole is being punched, so skip over any hole
2952 * already in the output file.
2955 vn_write_outvp(struct vnode *outvp, char *dat, off_t outoff, off_t xfer,
2956 u_long blksize, bool growfile, bool checkhole, struct ucred *cred)
2959 off_t dataoff, holeoff, xfer2;
2963 * Loop around doing writes of blksize until write has been completed.
2964 * Lock/unlock on each loop iteration so that a bwillwrite() can be
2965 * done for each iteration, since the xfer argument can be very
2966 * large if there is a large hole to punch in the output file.
2971 xfer2 = MIN(xfer, blksize);
2974 * Punching a hole. Skip writing if there is
2975 * already a hole in the output file.
2977 xfer2 = vn_skip_hole(outvp, xfer2, &outoff, &xfer,
2978 &dataoff, &holeoff, cred);
2983 KASSERT(xfer2 > 0, ("vn_write_outvp: xfer2=%jd",
2988 error = vn_start_write(outvp, &mp, V_WAIT);
2992 error = vn_lock(outvp, LK_EXCLUSIVE);
2994 error = vn_truncate_locked(outvp, outoff + xfer,
2999 if (MNT_SHARED_WRITES(mp))
3002 lckf = LK_EXCLUSIVE;
3003 error = vn_lock(outvp, lckf);
3005 error = vn_rdwr(UIO_WRITE, outvp, dat, xfer2,
3006 outoff, UIO_SYSSPACE, IO_NODELOCKED,
3007 curthread->td_ucred, cred, NULL, curthread);
3014 vn_finished_write(mp);
3015 } while (!growfile && xfer > 0 && error == 0);
3020 * Copy a byte range of one file to another. This function can handle the
3021 * case where invp and outvp are on different file systems.
3022 * It can also be called by a VOP_COPY_FILE_RANGE() to do the work, if there
3023 * is no better file system specific way to do it.
3026 vn_generic_copy_file_range(struct vnode *invp, off_t *inoffp,
3027 struct vnode *outvp, off_t *outoffp, size_t *lenp, unsigned int flags,
3028 struct ucred *incred, struct ucred *outcred, struct thread *fsize_td)
3033 off_t startoff, endoff, xfer, xfer2;
3035 int error, interrupted;
3036 bool cantseek, readzeros, eof, lastblock;
3038 size_t copylen, len, rem, savlen;
3040 long holein, holeout;
3042 holein = holeout = 0;
3043 savlen = len = *lenp;
3048 error = vn_lock(invp, LK_SHARED);
3051 if (VOP_PATHCONF(invp, _PC_MIN_HOLE_SIZE, &holein) != 0)
3056 error = vn_start_write(outvp, &mp, V_WAIT);
3058 error = vn_lock(outvp, LK_EXCLUSIVE);
3061 * If fsize_td != NULL, do a vn_rlimit_fsize() call,
3062 * now that outvp is locked.
3064 if (fsize_td != NULL) {
3065 io.uio_offset = *outoffp;
3067 error = vn_rlimit_fsize(outvp, &io, fsize_td);
3071 if (VOP_PATHCONF(outvp, _PC_MIN_HOLE_SIZE, &holeout) != 0)
3074 * Holes that are past EOF do not need to be written as a block
3075 * of zero bytes. So, truncate the output file as far as
3076 * possible and then use va.va_size to decide if writing 0
3077 * bytes is necessary in the loop below.
3080 error = VOP_GETATTR(outvp, &va, outcred);
3081 if (error == 0 && va.va_size > *outoffp && va.va_size <=
3084 error = mac_vnode_check_write(curthread->td_ucred,
3088 error = vn_truncate_locked(outvp, *outoffp,
3091 va.va_size = *outoffp;
3096 vn_finished_write(mp);
3101 * Set the blksize to the larger of the hole sizes for invp and outvp.
3102 * If hole sizes aren't available, set the blksize to the larger
3103 * f_iosize of invp and outvp.
3104 * This code expects the hole sizes and f_iosizes to be powers of 2.
3105 * This value is clipped at 4Kbytes and 1Mbyte.
3107 blksize = MAX(holein, holeout);
3109 /* Clip len to end at an exact multiple of hole size. */
3111 rem = *inoffp % blksize;
3113 rem = blksize - rem;
3114 if (len - rem > blksize)
3115 len = savlen = rounddown(len - rem, blksize) + rem;
3119 blksize = MAX(invp->v_mount->mnt_stat.f_iosize,
3120 outvp->v_mount->mnt_stat.f_iosize);
3123 else if (blksize > 1024 * 1024)
3124 blksize = 1024 * 1024;
3125 dat = malloc(blksize, M_TEMP, M_WAITOK);
3128 * If VOP_IOCTL(FIOSEEKHOLE) works for invp, use it and FIOSEEKDATA
3129 * to find holes. Otherwise, just scan the read block for all 0s
3130 * in the inner loop where the data copying is done.
3131 * Note that some file systems such as NFSv3, NFSv4.0 and NFSv4.1 may
3132 * support holes on the server, but do not support FIOSEEKHOLE.
3135 while (len > 0 && error == 0 && !eof && interrupted == 0) {
3136 endoff = 0; /* To shut up compilers. */
3142 * Find the next data area. If there is just a hole to EOF,
3143 * FIOSEEKDATA should fail and then we drop down into the
3144 * inner loop and create the hole on the outvp file.
3145 * (I do not know if any file system will report a hole to
3146 * EOF via FIOSEEKHOLE, but I am pretty sure FIOSEEKDATA
3147 * will fail for those file systems.)
3149 * For input files that don't support FIOSEEKDATA/FIOSEEKHOLE,
3150 * the code just falls through to the inner copy loop.
3154 error = VOP_IOCTL(invp, FIOSEEKDATA, &startoff, 0,
3158 error = VOP_IOCTL(invp, FIOSEEKHOLE, &endoff, 0,
3161 * Since invp is unlocked, it may be possible for
3162 * another thread to do a truncate(), lseek(), write()
3163 * creating a hole at startoff between the above
3164 * VOP_IOCTL() calls, if the other thread does not do
3166 * If that happens, startoff == endoff and finding
3167 * the hole has failed, so set an error.
3169 if (error == 0 && startoff == endoff)
3170 error = EINVAL; /* Any error. Reset to 0. */
3173 if (startoff > *inoffp) {
3174 /* Found hole before data block. */
3175 xfer = MIN(startoff - *inoffp, len);
3176 if (*outoffp < va.va_size) {
3177 /* Must write 0s to punch hole. */
3178 xfer2 = MIN(va.va_size - *outoffp,
3180 memset(dat, 0, MIN(xfer2, blksize));
3181 error = vn_write_outvp(outvp, dat,
3182 *outoffp, xfer2, blksize, false,
3183 holeout > 0, outcred);
3186 if (error == 0 && *outoffp + xfer >
3187 va.va_size && xfer == len)
3188 /* Grow last block. */
3189 error = vn_write_outvp(outvp, dat,
3190 *outoffp, xfer, blksize, true,
3197 interrupted = sig_intr();
3200 copylen = MIN(len, endoff - startoff);
3212 * Set first xfer to end at a block boundary, so that
3213 * holes are more likely detected in the loop below via
3214 * the for all bytes 0 method.
3216 xfer -= (*inoffp % blksize);
3218 /* Loop copying the data block. */
3219 while (copylen > 0 && error == 0 && !eof && interrupted == 0) {
3222 error = vn_lock(invp, LK_SHARED);
3225 error = vn_rdwr(UIO_READ, invp, dat, xfer,
3226 startoff, UIO_SYSSPACE, IO_NODELOCKED,
3227 curthread->td_ucred, incred, &aresid,
3231 if (error == 0 && aresid > 0) {
3232 /* Stop the copy at EOF on the input file. */
3239 * Skip the write for holes past the initial EOF
3240 * of the output file, unless this is the last
3241 * write of the output file at EOF.
3243 readzeros = cantseek ? mem_iszero(dat, xfer) :
3247 if (!cantseek || *outoffp < va.va_size ||
3248 lastblock || !readzeros)
3249 error = vn_write_outvp(outvp, dat,
3250 *outoffp, xfer, blksize,
3251 readzeros && lastblock &&
3252 *outoffp >= va.va_size, false,
3261 interrupted = sig_intr();
3268 *lenp = savlen - len;
3274 vn_fallocate(struct file *fp, off_t offset, off_t len, struct thread *td)
3278 off_t olen, ooffset;
3281 int audited_vnode1 = 0;
3285 if (vp->v_type != VREG)
3288 /* Allocating blocks may take a long time, so iterate. */
3295 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
3298 error = vn_lock(vp, LK_EXCLUSIVE);
3300 vn_finished_write(mp);
3304 if (!audited_vnode1) {
3305 AUDIT_ARG_VNODE1(vp);
3310 error = mac_vnode_check_write(td->td_ucred, fp->f_cred, vp);
3313 error = VOP_ALLOCATE(vp, &offset, &len);
3315 vn_finished_write(mp);
3317 if (olen + ooffset != offset + len) {
3318 panic("offset + len changed from %jx/%jx to %jx/%jx",
3319 ooffset, olen, offset, len);
3321 if (error != 0 || len == 0)
3323 KASSERT(olen > len, ("Iteration did not make progress?"));
3330 static u_long vn_lock_pair_pause_cnt;
3331 SYSCTL_ULONG(_debug, OID_AUTO, vn_lock_pair_pause, CTLFLAG_RD,
3332 &vn_lock_pair_pause_cnt, 0,
3333 "Count of vn_lock_pair deadlocks");
3336 vn_lock_pair_pause(const char *wmesg)
3338 atomic_add_long(&vn_lock_pair_pause_cnt, 1);
3339 pause(wmesg, prng32_bounded(hz / 10));
3343 * Lock pair of vnodes vp1, vp2, avoiding lock order reversal.
3344 * vp1_locked indicates whether vp1 is exclusively locked; if not, vp1
3345 * must be unlocked. Same for vp2 and vp2_locked. One of the vnodes
3348 * The function returns with both vnodes exclusively locked, and
3349 * guarantees that it does not create lock order reversal with other
3350 * threads during its execution. Both vnodes could be unlocked
3351 * temporary (and reclaimed).
3354 vn_lock_pair(struct vnode *vp1, bool vp1_locked, struct vnode *vp2,
3359 if (vp1 == NULL && vp2 == NULL)
3363 ASSERT_VOP_ELOCKED(vp1, "vp1");
3365 ASSERT_VOP_UNLOCKED(vp1, "vp1");
3371 ASSERT_VOP_ELOCKED(vp2, "vp2");
3373 ASSERT_VOP_UNLOCKED(vp2, "vp2");
3377 if (!vp1_locked && !vp2_locked) {
3378 vn_lock(vp1, LK_EXCLUSIVE | LK_RETRY);
3383 if (vp1_locked && vp2_locked)
3385 if (vp1_locked && vp2 != NULL) {
3387 error = VOP_LOCK1(vp2, LK_EXCLUSIVE | LK_NOWAIT,
3388 __FILE__, __LINE__);
3393 vn_lock_pair_pause("vlp1");
3395 vn_lock(vp2, LK_EXCLUSIVE | LK_RETRY);
3398 if (vp2_locked && vp1 != NULL) {
3400 error = VOP_LOCK1(vp1, LK_EXCLUSIVE | LK_NOWAIT,
3401 __FILE__, __LINE__);
3406 vn_lock_pair_pause("vlp2");
3408 vn_lock(vp1, LK_EXCLUSIVE | LK_RETRY);
3413 ASSERT_VOP_ELOCKED(vp1, "vp1 ret");
3415 ASSERT_VOP_ELOCKED(vp2, "vp2 ret");