2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1982, 1986, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
12 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
13 * Copyright (c) 2013, 2014 The FreeBSD Foundation
15 * Portions of this software were developed by Konstantin Belousov
16 * under sponsorship from the FreeBSD Foundation.
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted provided that the following conditions
21 * 1. Redistributions of source code must retain the above copyright
22 * notice, this list of conditions and the following disclaimer.
23 * 2. Redistributions in binary form must reproduce the above copyright
24 * notice, this list of conditions and the following disclaimer in the
25 * documentation and/or other materials provided with the distribution.
26 * 3. Neither the name of the University nor the names of its contributors
27 * may be used to endorse or promote products derived from this software
28 * without specific prior written permission.
30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
42 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
48 #include "opt_hwpmc_hooks.h"
50 #include <sys/param.h>
51 #include <sys/systm.h>
54 #include <sys/fcntl.h>
60 #include <sys/limits.h>
63 #include <sys/mount.h>
64 #include <sys/mutex.h>
65 #include <sys/namei.h>
66 #include <sys/vnode.h>
69 #include <sys/filio.h>
70 #include <sys/resourcevar.h>
71 #include <sys/rwlock.h>
73 #include <sys/sysctl.h>
74 #include <sys/ttycom.h>
76 #include <sys/syslog.h>
77 #include <sys/unistd.h>
80 #include <security/audit/audit.h>
81 #include <security/mac/mac_framework.h>
84 #include <vm/vm_extern.h>
86 #include <vm/vm_map.h>
87 #include <vm/vm_object.h>
88 #include <vm/vm_page.h>
89 #include <vm/vm_pager.h>
92 #include <sys/pmckern.h>
95 static fo_rdwr_t vn_read;
96 static fo_rdwr_t vn_write;
97 static fo_rdwr_t vn_io_fault;
98 static fo_truncate_t vn_truncate;
99 static fo_ioctl_t vn_ioctl;
100 static fo_poll_t vn_poll;
101 static fo_kqfilter_t vn_kqfilter;
102 static fo_stat_t vn_statfile;
103 static fo_close_t vn_closefile;
104 static fo_mmap_t vn_mmap;
106 struct fileops vnops = {
107 .fo_read = vn_io_fault,
108 .fo_write = vn_io_fault,
109 .fo_truncate = vn_truncate,
110 .fo_ioctl = vn_ioctl,
112 .fo_kqfilter = vn_kqfilter,
113 .fo_stat = vn_statfile,
114 .fo_close = vn_closefile,
115 .fo_chmod = vn_chmod,
116 .fo_chown = vn_chown,
117 .fo_sendfile = vn_sendfile,
119 .fo_fill_kinfo = vn_fill_kinfo,
121 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE
124 static const int io_hold_cnt = 16;
125 static int vn_io_fault_enable = 1;
126 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW,
127 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance");
128 static int vn_io_fault_prefault = 0;
129 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RW,
130 &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting");
131 static u_long vn_io_faults_cnt;
132 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD,
133 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers");
136 * Returns true if vn_io_fault mode of handling the i/o request should
140 do_vn_io_fault(struct vnode *vp, struct uio *uio)
144 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG &&
145 (mp = vp->v_mount) != NULL &&
146 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable);
150 * Structure used to pass arguments to vn_io_fault1(), to do either
151 * file- or vnode-based I/O calls.
153 struct vn_io_fault_args {
161 struct fop_args_tag {
165 struct vop_args_tag {
171 static int vn_io_fault1(struct vnode *vp, struct uio *uio,
172 struct vn_io_fault_args *args, struct thread *td);
175 vn_open(struct nameidata *ndp, int *flagp, int cmode, struct file *fp)
177 struct thread *td = ndp->ni_cnd.cn_thread;
179 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp));
183 * Common code for vnode open operations via a name lookup.
184 * Lookup the vnode and invoke VOP_CREATE if needed.
185 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
187 * Note that this does NOT free nameidata for the successful case,
188 * due to the NDINIT being done elsewhere.
191 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags,
192 struct ucred *cred, struct file *fp)
196 struct thread *td = ndp->ni_cnd.cn_thread;
198 struct vattr *vap = &vat;
203 if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT |
204 O_EXCL | O_DIRECTORY))
206 else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) {
207 ndp->ni_cnd.cn_nameiop = CREATE;
209 * Set NOCACHE to avoid flushing the cache when
210 * rolling in many files at once.
212 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF | NOCACHE;
213 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
214 ndp->ni_cnd.cn_flags |= FOLLOW;
215 if (!(vn_open_flags & VN_OPEN_NOAUDIT))
216 ndp->ni_cnd.cn_flags |= AUDITVNODE1;
217 if (vn_open_flags & VN_OPEN_NOCAPCHECK)
218 ndp->ni_cnd.cn_flags |= NOCAPCHECK;
219 if ((vn_open_flags & VN_OPEN_INVFS) == 0)
221 if ((error = namei(ndp)) != 0)
223 if (ndp->ni_vp == NULL) {
226 vap->va_mode = cmode;
228 vap->va_vaflags |= VA_EXCLUSIVE;
229 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) {
230 NDFREE(ndp, NDF_ONLY_PNBUF);
232 if ((error = vn_start_write(NULL, &mp,
233 V_XSLEEP | PCATCH)) != 0)
237 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0)
238 ndp->ni_cnd.cn_flags |= MAKEENTRY;
240 error = mac_vnode_check_create(cred, ndp->ni_dvp,
244 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
247 vn_finished_write(mp);
249 NDFREE(ndp, NDF_ONLY_PNBUF);
255 if (ndp->ni_dvp == ndp->ni_vp)
261 if (fmode & O_EXCL) {
265 if (vp->v_type == VDIR) {
272 ndp->ni_cnd.cn_nameiop = LOOKUP;
273 ndp->ni_cnd.cn_flags = ISOPEN |
274 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF;
275 if (!(fmode & FWRITE))
276 ndp->ni_cnd.cn_flags |= LOCKSHARED;
277 if (!(vn_open_flags & VN_OPEN_NOAUDIT))
278 ndp->ni_cnd.cn_flags |= AUDITVNODE1;
279 if (vn_open_flags & VN_OPEN_NOCAPCHECK)
280 ndp->ni_cnd.cn_flags |= NOCAPCHECK;
281 if ((error = namei(ndp)) != 0)
285 error = vn_open_vnode(vp, fmode, cred, td, fp);
291 NDFREE(ndp, NDF_ONLY_PNBUF);
299 vn_open_vnode_advlock(struct vnode *vp, int fmode, struct file *fp)
302 int error, lock_flags, type;
304 ASSERT_VOP_LOCKED(vp, "vn_open_vnode_advlock");
305 if ((fmode & (O_EXLOCK | O_SHLOCK)) == 0)
307 KASSERT(fp != NULL, ("open with flock requires fp"));
308 if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE)
311 lock_flags = VOP_ISLOCKED(vp);
314 lf.l_whence = SEEK_SET;
317 lf.l_type = (fmode & O_EXLOCK) != 0 ? F_WRLCK : F_RDLCK;
319 if ((fmode & FNONBLOCK) == 0)
321 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type);
323 fp->f_flag |= FHASLOCK;
325 vn_lock(vp, lock_flags | LK_RETRY);
326 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0)
332 * Common code for vnode open operations once a vnode is located.
333 * Check permissions, and call the VOP_OPEN routine.
336 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred,
337 struct thread *td, struct file *fp)
342 if (vp->v_type == VLNK)
344 if (vp->v_type == VSOCK)
346 if (vp->v_type != VDIR && fmode & O_DIRECTORY)
349 if (fmode & (FWRITE | O_TRUNC)) {
350 if (vp->v_type == VDIR)
358 if ((fmode & O_APPEND) && (fmode & FWRITE))
363 if (fmode & O_VERIFY)
365 error = mac_vnode_check_open(cred, vp, accmode);
369 accmode &= ~(VCREAT | VVERIFY);
371 if ((fmode & O_CREAT) == 0 && accmode != 0) {
372 error = VOP_ACCESS(vp, accmode, cred, td);
376 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
377 vn_lock(vp, LK_UPGRADE | LK_RETRY);
378 error = VOP_OPEN(vp, fmode, cred, td, fp);
382 error = vn_open_vnode_advlock(vp, fmode, fp);
383 if (error == 0 && (fmode & FWRITE) != 0) {
384 error = VOP_ADD_WRITECOUNT(vp, 1);
386 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
387 __func__, vp, vp->v_writecount);
392 * Error from advlock or VOP_ADD_WRITECOUNT() still requires
393 * calling VOP_CLOSE() to pair with earlier VOP_OPEN().
394 * Arrange for that by having fdrop() to use vn_closefile().
397 fp->f_flag |= FOPENFAILED;
399 if (fp->f_ops == &badfileops) {
400 fp->f_type = DTYPE_VNODE;
406 ASSERT_VOP_LOCKED(vp, "vn_open_vnode");
412 * Check for write permissions on the specified vnode.
413 * Prototype text segments cannot be written.
417 vn_writechk(struct vnode *vp)
420 ASSERT_VOP_LOCKED(vp, "vn_writechk");
422 * If there's shared text associated with
423 * the vnode, try to free it up once. If
424 * we fail, we can't allow writing.
436 vn_close1(struct vnode *vp, int flags, struct ucred *file_cred,
437 struct thread *td, bool keep_ref)
440 int error, lock_flags;
442 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 &&
443 MNT_EXTENDED_SHARED(vp->v_mount))
444 lock_flags = LK_SHARED;
446 lock_flags = LK_EXCLUSIVE;
448 vn_start_write(vp, &mp, V_WAIT);
449 vn_lock(vp, lock_flags | LK_RETRY);
450 AUDIT_ARG_VNODE1(vp);
451 if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) {
452 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
453 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
454 __func__, vp, vp->v_writecount);
456 error = VOP_CLOSE(vp, flags, file_cred, td);
461 vn_finished_write(mp);
466 vn_close(struct vnode *vp, int flags, struct ucred *file_cred,
470 return (vn_close1(vp, flags, file_cred, td, false));
474 * Heuristic to detect sequential operation.
477 sequential_heuristic(struct uio *uio, struct file *fp)
480 ASSERT_VOP_LOCKED(fp->f_vnode, __func__);
481 if (fp->f_flag & FRDAHEAD)
482 return (fp->f_seqcount << IO_SEQSHIFT);
485 * Offset 0 is handled specially. open() sets f_seqcount to 1 so
486 * that the first I/O is normally considered to be slightly
487 * sequential. Seeking to offset 0 doesn't change sequentiality
488 * unless previous seeks have reduced f_seqcount to 0, in which
489 * case offset 0 is not special.
491 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) ||
492 uio->uio_offset == fp->f_nextoff) {
494 * f_seqcount is in units of fixed-size blocks so that it
495 * depends mainly on the amount of sequential I/O and not
496 * much on the number of sequential I/O's. The fixed size
497 * of 16384 is hard-coded here since it is (not quite) just
498 * a magic size that works well here. This size is more
499 * closely related to the best I/O size for real disks than
500 * to any block size used by software.
502 if (uio->uio_resid >= IO_SEQMAX * 16384)
503 fp->f_seqcount = IO_SEQMAX;
505 fp->f_seqcount += howmany(uio->uio_resid, 16384);
506 if (fp->f_seqcount > IO_SEQMAX)
507 fp->f_seqcount = IO_SEQMAX;
509 return (fp->f_seqcount << IO_SEQSHIFT);
512 /* Not sequential. Quickly draw-down sequentiality. */
513 if (fp->f_seqcount > 1)
521 * Package up an I/O request on a vnode into a uio and do it.
524 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset,
525 enum uio_seg segflg, int ioflg, struct ucred *active_cred,
526 struct ucred *file_cred, ssize_t *aresid, struct thread *td)
533 struct vn_io_fault_args args;
534 int error, lock_flags;
536 if (offset < 0 && vp->v_type != VCHR)
538 auio.uio_iov = &aiov;
540 aiov.iov_base = base;
542 auio.uio_resid = len;
543 auio.uio_offset = offset;
544 auio.uio_segflg = segflg;
549 if ((ioflg & IO_NODELOCKED) == 0) {
550 if ((ioflg & IO_RANGELOCKED) == 0) {
551 if (rw == UIO_READ) {
552 rl_cookie = vn_rangelock_rlock(vp, offset,
555 rl_cookie = vn_rangelock_wlock(vp, offset,
561 if (rw == UIO_WRITE) {
562 if (vp->v_type != VCHR &&
563 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH))
566 if (MNT_SHARED_WRITES(mp) ||
567 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount)))
568 lock_flags = LK_SHARED;
570 lock_flags = LK_EXCLUSIVE;
572 lock_flags = LK_SHARED;
573 vn_lock(vp, lock_flags | LK_RETRY);
577 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
579 if ((ioflg & IO_NOMACCHECK) == 0) {
581 error = mac_vnode_check_read(active_cred, file_cred,
584 error = mac_vnode_check_write(active_cred, file_cred,
589 if (file_cred != NULL)
593 if (do_vn_io_fault(vp, &auio)) {
594 args.kind = VN_IO_FAULT_VOP;
597 args.args.vop_args.vp = vp;
598 error = vn_io_fault1(vp, &auio, &args, td);
599 } else if (rw == UIO_READ) {
600 error = VOP_READ(vp, &auio, ioflg, cred);
601 } else /* if (rw == UIO_WRITE) */ {
602 error = VOP_WRITE(vp, &auio, ioflg, cred);
606 *aresid = auio.uio_resid;
608 if (auio.uio_resid && error == 0)
610 if ((ioflg & IO_NODELOCKED) == 0) {
613 vn_finished_write(mp);
616 if (rl_cookie != NULL)
617 vn_rangelock_unlock(vp, rl_cookie);
622 * Package up an I/O request on a vnode into a uio and do it. The I/O
623 * request is split up into smaller chunks and we try to avoid saturating
624 * the buffer cache while potentially holding a vnode locked, so we
625 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield()
626 * to give other processes a chance to lock the vnode (either other processes
627 * core'ing the same binary, or unrelated processes scanning the directory).
630 vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, void *base, size_t len,
631 off_t offset, enum uio_seg segflg, int ioflg, struct ucred *active_cred,
632 struct ucred *file_cred, size_t *aresid, struct thread *td)
641 * Force `offset' to a multiple of MAXBSIZE except possibly
642 * for the first chunk, so that filesystems only need to
643 * write full blocks except possibly for the first and last
646 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE;
650 if (rw != UIO_READ && vp->v_type == VREG)
653 error = vn_rdwr(rw, vp, base, chunk, offset, segflg,
654 ioflg, active_cred, file_cred, &iaresid, td);
655 len -= chunk; /* aresid calc already includes length */
659 base = (char *)base + chunk;
660 kern_yield(PRI_USER);
663 *aresid = len + iaresid;
668 foffset_lock(struct file *fp, int flags)
673 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
675 #if OFF_MAX <= LONG_MAX
677 * Caller only wants the current f_offset value. Assume that
678 * the long and shorter integer types reads are atomic.
680 if ((flags & FOF_NOLOCK) != 0)
681 return (fp->f_offset);
685 * According to McKusick the vn lock was protecting f_offset here.
686 * It is now protected by the FOFFSET_LOCKED flag.
688 mtxp = mtx_pool_find(mtxpool_sleep, fp);
690 if ((flags & FOF_NOLOCK) == 0) {
691 while (fp->f_vnread_flags & FOFFSET_LOCKED) {
692 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING;
693 msleep(&fp->f_vnread_flags, mtxp, PUSER -1,
696 fp->f_vnread_flags |= FOFFSET_LOCKED;
704 foffset_unlock(struct file *fp, off_t val, int flags)
708 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
710 #if OFF_MAX <= LONG_MAX
711 if ((flags & FOF_NOLOCK) != 0) {
712 if ((flags & FOF_NOUPDATE) == 0)
714 if ((flags & FOF_NEXTOFF) != 0)
720 mtxp = mtx_pool_find(mtxpool_sleep, fp);
722 if ((flags & FOF_NOUPDATE) == 0)
724 if ((flags & FOF_NEXTOFF) != 0)
726 if ((flags & FOF_NOLOCK) == 0) {
727 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0,
728 ("Lost FOFFSET_LOCKED"));
729 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING)
730 wakeup(&fp->f_vnread_flags);
731 fp->f_vnread_flags = 0;
737 foffset_lock_uio(struct file *fp, struct uio *uio, int flags)
740 if ((flags & FOF_OFFSET) == 0)
741 uio->uio_offset = foffset_lock(fp, flags);
745 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags)
748 if ((flags & FOF_OFFSET) == 0)
749 foffset_unlock(fp, uio->uio_offset, flags);
753 get_advice(struct file *fp, struct uio *uio)
758 ret = POSIX_FADV_NORMAL;
759 if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG)
762 mtxp = mtx_pool_find(mtxpool_sleep, fp);
764 if (fp->f_advice != NULL &&
765 uio->uio_offset >= fp->f_advice->fa_start &&
766 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end)
767 ret = fp->f_advice->fa_advice;
773 * File table vnode read routine.
776 vn_read(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
784 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
786 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
789 if (fp->f_flag & FNONBLOCK)
791 if (fp->f_flag & O_DIRECT)
793 advice = get_advice(fp, uio);
794 vn_lock(vp, LK_SHARED | LK_RETRY);
797 case POSIX_FADV_NORMAL:
798 case POSIX_FADV_SEQUENTIAL:
799 case POSIX_FADV_NOREUSE:
800 ioflag |= sequential_heuristic(uio, fp);
802 case POSIX_FADV_RANDOM:
803 /* Disable read-ahead for random I/O. */
806 orig_offset = uio->uio_offset;
809 error = mac_vnode_check_read(active_cred, fp->f_cred, vp);
812 error = VOP_READ(vp, uio, ioflag, fp->f_cred);
813 fp->f_nextoff = uio->uio_offset;
815 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
816 orig_offset != uio->uio_offset)
818 * Use POSIX_FADV_DONTNEED to flush pages and buffers
819 * for the backing file after a POSIX_FADV_NOREUSE
822 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
823 POSIX_FADV_DONTNEED);
828 * File table vnode write routine.
831 vn_write(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
837 int error, ioflag, lock_flags;
840 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
842 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
844 if (vp->v_type == VREG)
847 if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
849 if (fp->f_flag & FNONBLOCK)
851 if (fp->f_flag & O_DIRECT)
853 if ((fp->f_flag & O_FSYNC) ||
854 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
857 if (vp->v_type != VCHR &&
858 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
861 advice = get_advice(fp, uio);
863 if (MNT_SHARED_WRITES(mp) ||
864 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) {
865 lock_flags = LK_SHARED;
867 lock_flags = LK_EXCLUSIVE;
870 vn_lock(vp, lock_flags | LK_RETRY);
872 case POSIX_FADV_NORMAL:
873 case POSIX_FADV_SEQUENTIAL:
874 case POSIX_FADV_NOREUSE:
875 ioflag |= sequential_heuristic(uio, fp);
877 case POSIX_FADV_RANDOM:
878 /* XXX: Is this correct? */
881 orig_offset = uio->uio_offset;
884 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
887 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred);
888 fp->f_nextoff = uio->uio_offset;
890 if (vp->v_type != VCHR)
891 vn_finished_write(mp);
892 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
893 orig_offset != uio->uio_offset)
895 * Use POSIX_FADV_DONTNEED to flush pages and buffers
896 * for the backing file after a POSIX_FADV_NOREUSE
899 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
900 POSIX_FADV_DONTNEED);
906 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to
907 * prevent the following deadlock:
909 * Assume that the thread A reads from the vnode vp1 into userspace
910 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is
911 * currently not resident, then system ends up with the call chain
912 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] ->
913 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2)
914 * which establishes lock order vp1->vn_lock, then vp2->vn_lock.
915 * If, at the same time, thread B reads from vnode vp2 into buffer buf2
916 * backed by the pages of vnode vp1, and some page in buf2 is not
917 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock.
919 * To prevent the lock order reversal and deadlock, vn_io_fault() does
920 * not allow page faults to happen during VOP_READ() or VOP_WRITE().
921 * Instead, it first tries to do the whole range i/o with pagefaults
922 * disabled. If all pages in the i/o buffer are resident and mapped,
923 * VOP will succeed (ignoring the genuine filesystem errors).
924 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do
925 * i/o in chunks, with all pages in the chunk prefaulted and held
926 * using vm_fault_quick_hold_pages().
928 * Filesystems using this deadlock avoidance scheme should use the
929 * array of the held pages from uio, saved in the curthread->td_ma,
930 * instead of doing uiomove(). A helper function
931 * vn_io_fault_uiomove() converts uiomove request into
932 * uiomove_fromphys() over td_ma array.
934 * Since vnode locks do not cover the whole i/o anymore, rangelocks
935 * make the current i/o request atomic with respect to other i/os and
940 * Decode vn_io_fault_args and perform the corresponding i/o.
943 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio,
949 save = vm_fault_disable_pagefaults();
950 switch (args->kind) {
951 case VN_IO_FAULT_FOP:
952 error = (args->args.fop_args.doio)(args->args.fop_args.fp,
953 uio, args->cred, args->flags, td);
955 case VN_IO_FAULT_VOP:
956 if (uio->uio_rw == UIO_READ) {
957 error = VOP_READ(args->args.vop_args.vp, uio,
958 args->flags, args->cred);
959 } else if (uio->uio_rw == UIO_WRITE) {
960 error = VOP_WRITE(args->args.vop_args.vp, uio,
961 args->flags, args->cred);
965 panic("vn_io_fault_doio: unknown kind of io %d %d",
966 args->kind, uio->uio_rw);
968 vm_fault_enable_pagefaults(save);
973 vn_io_fault_touch(char *base, const struct uio *uio)
978 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1))
984 vn_io_fault_prefault_user(const struct uio *uio)
987 const struct iovec *iov;
992 KASSERT(uio->uio_segflg == UIO_USERSPACE,
993 ("vn_io_fault_prefault userspace"));
997 resid = uio->uio_resid;
998 base = iov->iov_base;
1001 error = vn_io_fault_touch(base, uio);
1004 if (len < PAGE_SIZE) {
1006 error = vn_io_fault_touch(base + len - 1, uio);
1011 if (++i >= uio->uio_iovcnt)
1013 iov = uio->uio_iov + i;
1014 base = iov->iov_base;
1026 * Common code for vn_io_fault(), agnostic to the kind of i/o request.
1027 * Uses vn_io_fault_doio() to make the call to an actual i/o function.
1028 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request
1029 * into args and call vn_io_fault1() to handle faults during the user
1030 * mode buffer accesses.
1033 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args,
1036 vm_page_t ma[io_hold_cnt + 2];
1037 struct uio *uio_clone, short_uio;
1038 struct iovec short_iovec[1];
1039 vm_page_t *prev_td_ma;
1041 vm_offset_t addr, end;
1044 int error, cnt, saveheld, prev_td_ma_cnt;
1046 if (vn_io_fault_prefault) {
1047 error = vn_io_fault_prefault_user(uio);
1049 return (error); /* Or ignore ? */
1052 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ;
1055 * The UFS follows IO_UNIT directive and replays back both
1056 * uio_offset and uio_resid if an error is encountered during the
1057 * operation. But, since the iovec may be already advanced,
1058 * uio is still in an inconsistent state.
1060 * Cache a copy of the original uio, which is advanced to the redo
1061 * point using UIO_NOCOPY below.
1063 uio_clone = cloneuio(uio);
1064 resid = uio->uio_resid;
1066 short_uio.uio_segflg = UIO_USERSPACE;
1067 short_uio.uio_rw = uio->uio_rw;
1068 short_uio.uio_td = uio->uio_td;
1070 error = vn_io_fault_doio(args, uio, td);
1071 if (error != EFAULT)
1074 atomic_add_long(&vn_io_faults_cnt, 1);
1075 uio_clone->uio_segflg = UIO_NOCOPY;
1076 uiomove(NULL, resid - uio->uio_resid, uio_clone);
1077 uio_clone->uio_segflg = uio->uio_segflg;
1079 saveheld = curthread_pflags_set(TDP_UIOHELD);
1080 prev_td_ma = td->td_ma;
1081 prev_td_ma_cnt = td->td_ma_cnt;
1083 while (uio_clone->uio_resid != 0) {
1084 len = uio_clone->uio_iov->iov_len;
1086 KASSERT(uio_clone->uio_iovcnt >= 1,
1087 ("iovcnt underflow"));
1088 uio_clone->uio_iov++;
1089 uio_clone->uio_iovcnt--;
1092 if (len > io_hold_cnt * PAGE_SIZE)
1093 len = io_hold_cnt * PAGE_SIZE;
1094 addr = (uintptr_t)uio_clone->uio_iov->iov_base;
1095 end = round_page(addr + len);
1100 cnt = atop(end - trunc_page(addr));
1102 * A perfectly misaligned address and length could cause
1103 * both the start and the end of the chunk to use partial
1104 * page. +2 accounts for such a situation.
1106 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map,
1107 addr, len, prot, ma, io_hold_cnt + 2);
1112 short_uio.uio_iov = &short_iovec[0];
1113 short_iovec[0].iov_base = (void *)addr;
1114 short_uio.uio_iovcnt = 1;
1115 short_uio.uio_resid = short_iovec[0].iov_len = len;
1116 short_uio.uio_offset = uio_clone->uio_offset;
1118 td->td_ma_cnt = cnt;
1120 error = vn_io_fault_doio(args, &short_uio, td);
1121 vm_page_unhold_pages(ma, cnt);
1122 adv = len - short_uio.uio_resid;
1124 uio_clone->uio_iov->iov_base =
1125 (char *)uio_clone->uio_iov->iov_base + adv;
1126 uio_clone->uio_iov->iov_len -= adv;
1127 uio_clone->uio_resid -= adv;
1128 uio_clone->uio_offset += adv;
1130 uio->uio_resid -= adv;
1131 uio->uio_offset += adv;
1133 if (error != 0 || adv == 0)
1136 td->td_ma = prev_td_ma;
1137 td->td_ma_cnt = prev_td_ma_cnt;
1138 curthread_pflags_restore(saveheld);
1140 free(uio_clone, M_IOV);
1145 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred,
1146 int flags, struct thread *td)
1151 struct vn_io_fault_args args;
1154 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write;
1156 foffset_lock_uio(fp, uio, flags);
1157 if (do_vn_io_fault(vp, uio)) {
1158 args.kind = VN_IO_FAULT_FOP;
1159 args.args.fop_args.fp = fp;
1160 args.args.fop_args.doio = doio;
1161 args.cred = active_cred;
1162 args.flags = flags | FOF_OFFSET;
1163 if (uio->uio_rw == UIO_READ) {
1164 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset,
1165 uio->uio_offset + uio->uio_resid);
1166 } else if ((fp->f_flag & O_APPEND) != 0 ||
1167 (flags & FOF_OFFSET) == 0) {
1168 /* For appenders, punt and lock the whole range. */
1169 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1171 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset,
1172 uio->uio_offset + uio->uio_resid);
1174 error = vn_io_fault1(vp, uio, &args, td);
1175 vn_rangelock_unlock(vp, rl_cookie);
1177 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td);
1179 foffset_unlock_uio(fp, uio, flags);
1184 * Helper function to perform the requested uiomove operation using
1185 * the held pages for io->uio_iov[0].iov_base buffer instead of
1186 * copyin/copyout. Access to the pages with uiomove_fromphys()
1187 * instead of iov_base prevents page faults that could occur due to
1188 * pmap_collect() invalidating the mapping created by
1189 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or
1190 * object cleanup revoking the write access from page mappings.
1192 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove()
1193 * instead of plain uiomove().
1196 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio)
1198 struct uio transp_uio;
1199 struct iovec transp_iov[1];
1205 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1206 uio->uio_segflg != UIO_USERSPACE)
1207 return (uiomove(data, xfersize, uio));
1209 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1210 transp_iov[0].iov_base = data;
1211 transp_uio.uio_iov = &transp_iov[0];
1212 transp_uio.uio_iovcnt = 1;
1213 if (xfersize > uio->uio_resid)
1214 xfersize = uio->uio_resid;
1215 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize;
1216 transp_uio.uio_offset = 0;
1217 transp_uio.uio_segflg = UIO_SYSSPACE;
1219 * Since transp_iov points to data, and td_ma page array
1220 * corresponds to original uio->uio_iov, we need to invert the
1221 * direction of the i/o operation as passed to
1222 * uiomove_fromphys().
1224 switch (uio->uio_rw) {
1226 transp_uio.uio_rw = UIO_READ;
1229 transp_uio.uio_rw = UIO_WRITE;
1232 transp_uio.uio_td = uio->uio_td;
1233 error = uiomove_fromphys(td->td_ma,
1234 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK,
1235 xfersize, &transp_uio);
1236 adv = xfersize - transp_uio.uio_resid;
1238 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) -
1239 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT);
1241 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1243 td->td_ma_cnt -= pgadv;
1244 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv;
1245 uio->uio_iov->iov_len -= adv;
1246 uio->uio_resid -= adv;
1247 uio->uio_offset += adv;
1252 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize,
1256 vm_offset_t iov_base;
1260 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1261 uio->uio_segflg != UIO_USERSPACE)
1262 return (uiomove_fromphys(ma, offset, xfersize, uio));
1264 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1265 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize;
1266 iov_base = (vm_offset_t)uio->uio_iov->iov_base;
1267 switch (uio->uio_rw) {
1269 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma,
1273 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK,
1277 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT);
1279 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1281 td->td_ma_cnt -= pgadv;
1282 uio->uio_iov->iov_base = (char *)(iov_base + cnt);
1283 uio->uio_iov->iov_len -= cnt;
1284 uio->uio_resid -= cnt;
1285 uio->uio_offset += cnt;
1291 * File table truncate routine.
1294 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred,
1306 * Lock the whole range for truncation. Otherwise split i/o
1307 * might happen partly before and partly after the truncation.
1309 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1310 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
1313 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1314 AUDIT_ARG_VNODE1(vp);
1315 if (vp->v_type == VDIR) {
1320 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
1324 error = VOP_ADD_WRITECOUNT(vp, 1);
1327 vattr.va_size = length;
1328 if ((fp->f_flag & O_FSYNC) != 0)
1329 vattr.va_vaflags |= VA_SYNC;
1330 error = VOP_SETATTR(vp, &vattr, fp->f_cred);
1331 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
1335 vn_finished_write(mp);
1337 vn_rangelock_unlock(vp, rl_cookie);
1342 * File table vnode stat routine.
1345 vn_statfile(struct file *fp, struct stat *sb, struct ucred *active_cred,
1348 struct vnode *vp = fp->f_vnode;
1351 vn_lock(vp, LK_SHARED | LK_RETRY);
1352 error = vn_stat(vp, sb, active_cred, fp->f_cred, td);
1359 * Stat a vnode; implementation for the stat syscall
1362 vn_stat(struct vnode *vp, struct stat *sb, struct ucred *active_cred,
1363 struct ucred *file_cred, struct thread *td)
1370 AUDIT_ARG_VNODE1(vp);
1372 error = mac_vnode_check_stat(active_cred, file_cred, vp);
1380 * Initialize defaults for new and unusual fields, so that file
1381 * systems which don't support these fields don't need to know
1384 vap->va_birthtime.tv_sec = -1;
1385 vap->va_birthtime.tv_nsec = 0;
1386 vap->va_fsid = VNOVAL;
1387 vap->va_rdev = NODEV;
1389 error = VOP_GETATTR(vp, vap, active_cred);
1394 * Zero the spare stat fields
1396 bzero(sb, sizeof *sb);
1399 * Copy from vattr table
1401 if (vap->va_fsid != VNOVAL)
1402 sb->st_dev = vap->va_fsid;
1404 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0];
1405 sb->st_ino = vap->va_fileid;
1406 mode = vap->va_mode;
1407 switch (vap->va_type) {
1433 sb->st_nlink = vap->va_nlink;
1434 sb->st_uid = vap->va_uid;
1435 sb->st_gid = vap->va_gid;
1436 sb->st_rdev = vap->va_rdev;
1437 if (vap->va_size > OFF_MAX)
1439 sb->st_size = vap->va_size;
1440 sb->st_atim = vap->va_atime;
1441 sb->st_mtim = vap->va_mtime;
1442 sb->st_ctim = vap->va_ctime;
1443 sb->st_birthtim = vap->va_birthtime;
1446 * According to www.opengroup.org, the meaning of st_blksize is
1447 * "a filesystem-specific preferred I/O block size for this
1448 * object. In some filesystem types, this may vary from file
1450 * Use miminum/default of PAGE_SIZE (e.g. for VCHR).
1453 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize);
1455 sb->st_flags = vap->va_flags;
1456 if (priv_check(td, PRIV_VFS_GENERATION))
1459 sb->st_gen = vap->va_gen;
1461 sb->st_blocks = vap->va_bytes / S_BLKSIZE;
1466 * File table vnode ioctl routine.
1469 vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
1474 struct fiobmap2_arg *bmarg;
1478 switch (vp->v_type) {
1483 vn_lock(vp, LK_SHARED | LK_RETRY);
1484 error = VOP_GETATTR(vp, &vattr, active_cred);
1487 *(int *)data = vattr.va_size - fp->f_offset;
1490 bmarg = (struct fiobmap2_arg *)data;
1491 vn_lock(vp, LK_SHARED | LK_RETRY);
1493 error = mac_vnode_check_read(active_cred, fp->f_cred,
1497 error = VOP_BMAP(vp, bmarg->bn, NULL,
1498 &bmarg->bn, &bmarg->runp, &bmarg->runb);
1505 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1510 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1518 * File table vnode poll routine.
1521 vn_poll(struct file *fp, int events, struct ucred *active_cred,
1529 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1530 AUDIT_ARG_VNODE1(vp);
1531 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp);
1536 error = VOP_POLL(vp, events, fp->f_cred, td);
1541 * Acquire the requested lock and then check for validity. LK_RETRY
1542 * permits vn_lock to return doomed vnodes.
1545 _vn_lock(struct vnode *vp, int flags, char *file, int line)
1549 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
1550 ("vn_lock: no locktype"));
1551 VNASSERT(vp->v_holdcnt != 0, vp, ("vn_lock: zero hold count"));
1553 error = VOP_LOCK1(vp, flags, file, line);
1554 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */
1555 KASSERT((flags & LK_RETRY) == 0 || error == 0,
1556 ("vn_lock: error %d incompatible with flags %#x", error, flags));
1558 if ((flags & LK_RETRY) == 0) {
1559 if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0) {
1563 } else if (error != 0)
1569 * File table vnode close routine.
1572 vn_closefile(struct file *fp, struct thread *td)
1580 fp->f_ops = &badfileops;
1581 ref= (fp->f_flag & FHASLOCK) != 0 && fp->f_type == DTYPE_VNODE;
1583 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref);
1585 if (__predict_false(ref)) {
1586 lf.l_whence = SEEK_SET;
1589 lf.l_type = F_UNLCK;
1590 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK);
1597 vn_suspendable(struct mount *mp)
1600 return (mp->mnt_op->vfs_susp_clean != NULL);
1604 * Preparing to start a filesystem write operation. If the operation is
1605 * permitted, then we bump the count of operations in progress and
1606 * proceed. If a suspend request is in progress, we wait until the
1607 * suspension is over, and then proceed.
1610 vn_start_write_locked(struct mount *mp, int flags)
1614 mtx_assert(MNT_MTX(mp), MA_OWNED);
1618 * Check on status of suspension.
1620 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 ||
1621 mp->mnt_susp_owner != curthread) {
1622 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ?
1623 (flags & PCATCH) : 0) | (PUSER - 1);
1624 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1625 if (flags & V_NOWAIT) {
1626 error = EWOULDBLOCK;
1629 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags,
1635 if (flags & V_XSLEEP)
1637 mp->mnt_writeopcount++;
1639 if (error != 0 || (flags & V_XSLEEP) != 0)
1646 vn_start_write(struct vnode *vp, struct mount **mpp, int flags)
1651 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1652 ("V_MNTREF requires mp"));
1656 * If a vnode is provided, get and return the mount point that
1657 * to which it will write.
1660 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1662 if (error != EOPNOTSUPP)
1667 if ((mp = *mpp) == NULL)
1670 if (!vn_suspendable(mp)) {
1671 if (vp != NULL || (flags & V_MNTREF) != 0)
1677 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1679 * As long as a vnode is not provided we need to acquire a
1680 * refcount for the provided mountpoint too, in order to
1681 * emulate a vfs_ref().
1684 if (vp == NULL && (flags & V_MNTREF) == 0)
1687 return (vn_start_write_locked(mp, flags));
1691 * Secondary suspension. Used by operations such as vop_inactive
1692 * routines that are needed by the higher level functions. These
1693 * are allowed to proceed until all the higher level functions have
1694 * completed (indicated by mnt_writeopcount dropping to zero). At that
1695 * time, these operations are halted until the suspension is over.
1698 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags)
1703 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1704 ("V_MNTREF requires mp"));
1708 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1710 if (error != EOPNOTSUPP)
1716 * If we are not suspended or have not yet reached suspended
1717 * mode, then let the operation proceed.
1719 if ((mp = *mpp) == NULL)
1722 if (!vn_suspendable(mp)) {
1723 if (vp != NULL || (flags & V_MNTREF) != 0)
1729 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1731 * As long as a vnode is not provided we need to acquire a
1732 * refcount for the provided mountpoint too, in order to
1733 * emulate a vfs_ref().
1736 if (vp == NULL && (flags & V_MNTREF) == 0)
1738 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) {
1739 mp->mnt_secondary_writes++;
1740 mp->mnt_secondary_accwrites++;
1744 if (flags & V_NOWAIT) {
1747 return (EWOULDBLOCK);
1750 * Wait for the suspension to finish.
1752 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP |
1753 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0),
1762 * Filesystem write operation has completed. If we are suspending and this
1763 * operation is the last one, notify the suspender that the suspension is
1767 vn_finished_write(struct mount *mp)
1769 if (mp == NULL || !vn_suspendable(mp))
1773 mp->mnt_writeopcount--;
1774 if (mp->mnt_writeopcount < 0)
1775 panic("vn_finished_write: neg cnt");
1776 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
1777 mp->mnt_writeopcount <= 0)
1778 wakeup(&mp->mnt_writeopcount);
1784 * Filesystem secondary write operation has completed. If we are
1785 * suspending and this operation is the last one, notify the suspender
1786 * that the suspension is now in effect.
1789 vn_finished_secondary_write(struct mount *mp)
1791 if (mp == NULL || !vn_suspendable(mp))
1795 mp->mnt_secondary_writes--;
1796 if (mp->mnt_secondary_writes < 0)
1797 panic("vn_finished_secondary_write: neg cnt");
1798 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
1799 mp->mnt_secondary_writes <= 0)
1800 wakeup(&mp->mnt_secondary_writes);
1807 * Request a filesystem to suspend write operations.
1810 vfs_write_suspend(struct mount *mp, int flags)
1814 MPASS(vn_suspendable(mp));
1817 if (mp->mnt_susp_owner == curthread) {
1821 while (mp->mnt_kern_flag & MNTK_SUSPEND)
1822 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0);
1825 * Unmount holds a write reference on the mount point. If we
1826 * own busy reference and drain for writers, we deadlock with
1827 * the reference draining in the unmount path. Callers of
1828 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if
1829 * vfs_busy() reference is owned and caller is not in the
1832 if ((flags & VS_SKIP_UNMOUNT) != 0 &&
1833 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) {
1838 mp->mnt_kern_flag |= MNTK_SUSPEND;
1839 mp->mnt_susp_owner = curthread;
1840 if (mp->mnt_writeopcount > 0)
1841 (void) msleep(&mp->mnt_writeopcount,
1842 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0);
1845 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0)
1846 vfs_write_resume(mp, 0);
1851 * Request a filesystem to resume write operations.
1854 vfs_write_resume(struct mount *mp, int flags)
1857 MPASS(vn_suspendable(mp));
1860 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1861 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner"));
1862 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 |
1864 mp->mnt_susp_owner = NULL;
1865 wakeup(&mp->mnt_writeopcount);
1866 wakeup(&mp->mnt_flag);
1867 curthread->td_pflags &= ~TDP_IGNSUSP;
1868 if ((flags & VR_START_WRITE) != 0) {
1870 mp->mnt_writeopcount++;
1873 if ((flags & VR_NO_SUSPCLR) == 0)
1875 } else if ((flags & VR_START_WRITE) != 0) {
1877 vn_start_write_locked(mp, 0);
1884 * Helper loop around vfs_write_suspend() for filesystem unmount VFS
1888 vfs_write_suspend_umnt(struct mount *mp)
1892 MPASS(vn_suspendable(mp));
1893 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0,
1894 ("vfs_write_suspend_umnt: recursed"));
1896 /* dounmount() already called vn_start_write(). */
1898 vn_finished_write(mp);
1899 error = vfs_write_suspend(mp, 0);
1901 vn_start_write(NULL, &mp, V_WAIT);
1905 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0)
1908 vn_start_write(NULL, &mp, V_WAIT);
1910 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2);
1911 wakeup(&mp->mnt_flag);
1913 curthread->td_pflags |= TDP_IGNSUSP;
1918 * Implement kqueues for files by translating it to vnode operation.
1921 vn_kqfilter(struct file *fp, struct knote *kn)
1924 return (VOP_KQFILTER(fp->f_vnode, kn));
1928 * Simplified in-kernel wrapper calls for extended attribute access.
1929 * Both calls pass in a NULL credential, authorizing as "kernel" access.
1930 * Set IO_NODELOCKED in ioflg if the vnode is already locked.
1933 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace,
1934 const char *attrname, int *buflen, char *buf, struct thread *td)
1940 iov.iov_len = *buflen;
1943 auio.uio_iov = &iov;
1944 auio.uio_iovcnt = 1;
1945 auio.uio_rw = UIO_READ;
1946 auio.uio_segflg = UIO_SYSSPACE;
1948 auio.uio_offset = 0;
1949 auio.uio_resid = *buflen;
1951 if ((ioflg & IO_NODELOCKED) == 0)
1952 vn_lock(vp, LK_SHARED | LK_RETRY);
1954 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
1956 /* authorize attribute retrieval as kernel */
1957 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL,
1960 if ((ioflg & IO_NODELOCKED) == 0)
1964 *buflen = *buflen - auio.uio_resid;
1971 * XXX failure mode if partially written?
1974 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace,
1975 const char *attrname, int buflen, char *buf, struct thread *td)
1982 iov.iov_len = buflen;
1985 auio.uio_iov = &iov;
1986 auio.uio_iovcnt = 1;
1987 auio.uio_rw = UIO_WRITE;
1988 auio.uio_segflg = UIO_SYSSPACE;
1990 auio.uio_offset = 0;
1991 auio.uio_resid = buflen;
1993 if ((ioflg & IO_NODELOCKED) == 0) {
1994 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
1996 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1999 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2001 /* authorize attribute setting as kernel */
2002 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td);
2004 if ((ioflg & IO_NODELOCKED) == 0) {
2005 vn_finished_write(mp);
2013 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace,
2014 const char *attrname, struct thread *td)
2019 if ((ioflg & IO_NODELOCKED) == 0) {
2020 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2022 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2025 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2027 /* authorize attribute removal as kernel */
2028 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td);
2029 if (error == EOPNOTSUPP)
2030 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL,
2033 if ((ioflg & IO_NODELOCKED) == 0) {
2034 vn_finished_write(mp);
2042 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags,
2046 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp));
2050 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp)
2053 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino,
2058 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg,
2059 int lkflags, struct vnode **rvp)
2064 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get");
2066 ltype = VOP_ISLOCKED(vp);
2067 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED,
2068 ("vn_vget_ino: vp not locked"));
2069 error = vfs_busy(mp, MBF_NOWAIT);
2073 error = vfs_busy(mp, 0);
2074 vn_lock(vp, ltype | LK_RETRY);
2078 if (vp->v_iflag & VI_DOOMED) {
2084 error = alloc(mp, alloc_arg, lkflags, rvp);
2086 if (error != 0 || *rvp != vp)
2087 vn_lock(vp, ltype | LK_RETRY);
2088 if (vp->v_iflag & VI_DOOMED) {
2101 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio,
2105 if (vp->v_type != VREG || td == NULL)
2107 if ((uoff_t)uio->uio_offset + uio->uio_resid >
2108 lim_cur(td, RLIMIT_FSIZE)) {
2109 PROC_LOCK(td->td_proc);
2110 kern_psignal(td->td_proc, SIGXFSZ);
2111 PROC_UNLOCK(td->td_proc);
2118 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
2125 vn_lock(vp, LK_SHARED | LK_RETRY);
2126 AUDIT_ARG_VNODE1(vp);
2129 return (setfmode(td, active_cred, vp, mode));
2133 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
2140 vn_lock(vp, LK_SHARED | LK_RETRY);
2141 AUDIT_ARG_VNODE1(vp);
2144 return (setfown(td, active_cred, vp, uid, gid));
2148 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end)
2152 if ((object = vp->v_object) == NULL)
2154 VM_OBJECT_WLOCK(object);
2155 vm_object_page_remove(object, start, end, 0);
2156 VM_OBJECT_WUNLOCK(object);
2160 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred)
2168 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
2169 ("Wrong command %lu", cmd));
2171 if (vn_lock(vp, LK_SHARED) != 0)
2173 if (vp->v_type != VREG) {
2177 error = VOP_GETATTR(vp, &va, cred);
2181 if (noff >= va.va_size) {
2185 bsize = vp->v_mount->mnt_stat.f_iosize;
2186 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize -
2188 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL);
2189 if (error == EOPNOTSUPP) {
2193 if ((bnp == -1 && cmd == FIOSEEKHOLE) ||
2194 (bnp != -1 && cmd == FIOSEEKDATA)) {
2201 if (noff > va.va_size)
2203 /* noff == va.va_size. There is an implicit hole at the end of file. */
2204 if (cmd == FIOSEEKDATA)
2214 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td)
2219 off_t foffset, size;
2222 cred = td->td_ucred;
2224 foffset = foffset_lock(fp, 0);
2225 noneg = (vp->v_type != VCHR);
2231 (offset > 0 && foffset > OFF_MAX - offset))) {
2238 vn_lock(vp, LK_SHARED | LK_RETRY);
2239 error = VOP_GETATTR(vp, &vattr, cred);
2245 * If the file references a disk device, then fetch
2246 * the media size and use that to determine the ending
2249 if (vattr.va_size == 0 && vp->v_type == VCHR &&
2250 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0)
2251 vattr.va_size = size;
2253 (vattr.va_size > OFF_MAX ||
2254 (offset > 0 && vattr.va_size > OFF_MAX - offset))) {
2258 offset += vattr.va_size;
2263 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td);
2266 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td);
2271 if (error == 0 && noneg && offset < 0)
2275 VFS_KNOTE_UNLOCKED(vp, 0);
2276 td->td_uretoff.tdu_off = offset;
2278 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0);
2283 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred,
2289 * Grant permission if the caller is the owner of the file, or
2290 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on
2291 * on the file. If the time pointer is null, then write
2292 * permission on the file is also sufficient.
2294 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes:
2295 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES
2296 * will be allowed to set the times [..] to the current
2299 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td);
2300 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0)
2301 error = VOP_ACCESS(vp, VWRITE, cred, td);
2306 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
2311 if (fp->f_type == DTYPE_FIFO)
2312 kif->kf_type = KF_TYPE_FIFO;
2314 kif->kf_type = KF_TYPE_VNODE;
2317 FILEDESC_SUNLOCK(fdp);
2318 error = vn_fill_kinfo_vnode(vp, kif);
2320 FILEDESC_SLOCK(fdp);
2325 vn_fill_junk(struct kinfo_file *kif)
2330 * Simulate vn_fullpath returning changing values for a given
2331 * vp during e.g. coredump.
2333 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1;
2334 olen = strlen(kif->kf_path);
2336 strcpy(&kif->kf_path[len - 1], "$");
2338 for (; olen < len; olen++)
2339 strcpy(&kif->kf_path[olen], "A");
2343 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif)
2346 char *fullpath, *freepath;
2349 kif->kf_un.kf_file.kf_file_type = vntype_to_kinfo(vp->v_type);
2352 error = vn_fullpath(curthread, vp, &fullpath, &freepath);
2354 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
2356 if (freepath != NULL)
2357 free(freepath, M_TEMP);
2359 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path,
2364 * Retrieve vnode attributes.
2366 va.va_fsid = VNOVAL;
2368 vn_lock(vp, LK_SHARED | LK_RETRY);
2369 error = VOP_GETATTR(vp, &va, curthread->td_ucred);
2373 if (va.va_fsid != VNOVAL)
2374 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid;
2376 kif->kf_un.kf_file.kf_file_fsid =
2377 vp->v_mount->mnt_stat.f_fsid.val[0];
2378 kif->kf_un.kf_file.kf_file_fsid_freebsd11 =
2379 kif->kf_un.kf_file.kf_file_fsid; /* truncate */
2380 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid;
2381 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode);
2382 kif->kf_un.kf_file.kf_file_size = va.va_size;
2383 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev;
2384 kif->kf_un.kf_file.kf_file_rdev_freebsd11 =
2385 kif->kf_un.kf_file.kf_file_rdev; /* truncate */
2390 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
2391 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
2395 struct pmckern_map_in pkm;
2401 boolean_t writecounted;
2404 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
2405 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
2407 * POSIX shared-memory objects are defined to have
2408 * kernel persistence, and are not defined to support
2409 * read(2)/write(2) -- or even open(2). Thus, we can
2410 * use MAP_ASYNC to trade on-disk coherence for speed.
2411 * The shm_open(3) library routine turns on the FPOSIXSHM
2412 * flag to request this behavior.
2414 if ((fp->f_flag & FPOSIXSHM) != 0)
2415 flags |= MAP_NOSYNC;
2420 * Ensure that file and memory protections are
2421 * compatible. Note that we only worry about
2422 * writability if mapping is shared; in this case,
2423 * current and max prot are dictated by the open file.
2424 * XXX use the vnode instead? Problem is: what
2425 * credentials do we use for determination? What if
2426 * proc does a setuid?
2429 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) {
2430 maxprot = VM_PROT_NONE;
2431 if ((prot & VM_PROT_EXECUTE) != 0)
2434 maxprot = VM_PROT_EXECUTE;
2435 if ((fp->f_flag & FREAD) != 0)
2436 maxprot |= VM_PROT_READ;
2437 else if ((prot & VM_PROT_READ) != 0)
2441 * If we are sharing potential changes via MAP_SHARED and we
2442 * are trying to get write permission although we opened it
2443 * without asking for it, bail out.
2445 if ((flags & MAP_SHARED) != 0) {
2446 if ((fp->f_flag & FWRITE) != 0)
2447 maxprot |= VM_PROT_WRITE;
2448 else if ((prot & VM_PROT_WRITE) != 0)
2451 maxprot |= VM_PROT_WRITE;
2452 cap_maxprot |= VM_PROT_WRITE;
2454 maxprot &= cap_maxprot;
2457 * For regular files and shared memory, POSIX requires that
2458 * the value of foff be a legitimate offset within the data
2459 * object. In particular, negative offsets are invalid.
2460 * Blocking negative offsets and overflows here avoids
2461 * possible wraparound or user-level access into reserved
2462 * ranges of the data object later. In contrast, POSIX does
2463 * not dictate how offsets are used by device drivers, so in
2464 * the case of a device mapping a negative offset is passed
2471 foff < 0 || foff > OFF_MAX - size)
2474 writecounted = FALSE;
2475 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp,
2476 &foff, &object, &writecounted);
2479 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
2480 foff, writecounted, td);
2483 * If this mapping was accounted for in the vnode's
2484 * writecount, then undo that now.
2487 vm_pager_release_writecount(object, 0, size);
2488 vm_object_deallocate(object);
2491 /* Inform hwpmc(4) if an executable is being mapped. */
2492 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) {
2493 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) {
2495 pkm.pm_address = (uintptr_t) *addr;
2496 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_MMAP, (void *) &pkm);
2504 vn_fsid(struct vnode *vp, struct vattr *va)
2508 f = &vp->v_mount->mnt_stat.f_fsid;
2509 va->va_fsid = (uint32_t)f->val[1];
2510 va->va_fsid <<= sizeof(f->val[1]) * NBBY;
2511 va->va_fsid += (uint32_t)f->val[0];
2515 vn_fsync_buf(struct vnode *vp, int waitfor)
2517 struct buf *bp, *nbp;
2520 int error, maxretry;
2523 maxretry = 10000; /* large, arbitrarily chosen */
2525 if (vp->v_type == VCHR) {
2527 mp = vp->v_rdev->si_mountpt;
2534 * MARK/SCAN initialization to avoid infinite loops.
2536 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) {
2537 bp->b_vflags &= ~BV_SCANNED;
2542 * Flush all dirty buffers associated with a vnode.
2545 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
2546 if ((bp->b_vflags & BV_SCANNED) != 0)
2548 bp->b_vflags |= BV_SCANNED;
2549 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) {
2550 if (waitfor != MNT_WAIT)
2553 LK_EXCLUSIVE | LK_INTERLOCK | LK_SLEEPFAIL,
2554 BO_LOCKPTR(bo)) != 0) {
2561 KASSERT(bp->b_bufobj == bo,
2562 ("bp %p wrong b_bufobj %p should be %p",
2563 bp, bp->b_bufobj, bo));
2564 if ((bp->b_flags & B_DELWRI) == 0)
2565 panic("fsync: not dirty");
2566 if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) {
2572 if (maxretry < 1000)
2573 pause("dirty", hz < 1000 ? 1 : hz / 1000);
2579 * If synchronous the caller expects us to completely resolve all
2580 * dirty buffers in the system. Wait for in-progress I/O to
2581 * complete (which could include background bitmap writes), then
2582 * retry if dirty blocks still exist.
2584 if (waitfor == MNT_WAIT) {
2585 bufobj_wwait(bo, 0, 0);
2586 if (bo->bo_dirty.bv_cnt > 0) {
2588 * If we are unable to write any of these buffers
2589 * then we fail now rather than trying endlessly
2590 * to write them out.
2592 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs)
2593 if ((error = bp->b_error) != 0)
2595 if ((mp != NULL && mp->mnt_secondary_writes > 0) ||
2596 (error == 0 && --maxretry >= 0))
2604 vn_printf(vp, "fsync: giving up on dirty (error = %d) ", error);