2 * Copyright (c) 1982, 1986, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
10 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
11 * Copyright (c) 2013, 2014 The FreeBSD Foundation
13 * Portions of this software were developed by Konstantin Belousov
14 * under sponsorship from the FreeBSD Foundation.
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
19 * 1. Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution.
24 * 4. Neither the name of the University nor the names of its contributors
25 * may be used to endorse or promote products derived from this software
26 * without specific prior written permission.
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
46 #include <sys/param.h>
47 #include <sys/systm.h>
49 #include <sys/fcntl.h>
55 #include <sys/limits.h>
57 #include <sys/mount.h>
58 #include <sys/mutex.h>
59 #include <sys/namei.h>
60 #include <sys/vnode.h>
63 #include <sys/filio.h>
64 #include <sys/resourcevar.h>
65 #include <sys/rwlock.h>
67 #include <sys/sysctl.h>
68 #include <sys/ttycom.h>
70 #include <sys/syslog.h>
71 #include <sys/unistd.h>
74 #include <security/audit/audit.h>
75 #include <security/mac/mac_framework.h>
78 #include <vm/vm_extern.h>
80 #include <vm/vm_map.h>
81 #include <vm/vm_object.h>
82 #include <vm/vm_page.h>
84 static fo_rdwr_t vn_read;
85 static fo_rdwr_t vn_write;
86 static fo_rdwr_t vn_io_fault;
87 static fo_truncate_t vn_truncate;
88 static fo_ioctl_t vn_ioctl;
89 static fo_poll_t vn_poll;
90 static fo_kqfilter_t vn_kqfilter;
91 static fo_stat_t vn_statfile;
92 static fo_close_t vn_closefile;
94 struct fileops vnops = {
95 .fo_read = vn_io_fault,
96 .fo_write = vn_io_fault,
97 .fo_truncate = vn_truncate,
100 .fo_kqfilter = vn_kqfilter,
101 .fo_stat = vn_statfile,
102 .fo_close = vn_closefile,
103 .fo_chmod = vn_chmod,
104 .fo_chown = vn_chown,
105 .fo_sendfile = vn_sendfile,
107 .fo_fill_kinfo = vn_fill_kinfo,
108 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE
111 static const int io_hold_cnt = 16;
112 static int vn_io_fault_enable = 1;
113 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RW,
114 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance");
115 static u_long vn_io_faults_cnt;
116 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD,
117 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers");
120 * Returns true if vn_io_fault mode of handling the i/o request should
124 do_vn_io_fault(struct vnode *vp, struct uio *uio)
128 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG &&
129 (mp = vp->v_mount) != NULL &&
130 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable);
134 * Structure used to pass arguments to vn_io_fault1(), to do either
135 * file- or vnode-based I/O calls.
137 struct vn_io_fault_args {
145 struct fop_args_tag {
149 struct vop_args_tag {
155 static int vn_io_fault1(struct vnode *vp, struct uio *uio,
156 struct vn_io_fault_args *args, struct thread *td);
159 vn_open(ndp, flagp, cmode, fp)
160 struct nameidata *ndp;
164 struct thread *td = ndp->ni_cnd.cn_thread;
166 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp));
170 * Common code for vnode open operations via a name lookup.
171 * Lookup the vnode and invoke VOP_CREATE if needed.
172 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
174 * Note that this does NOT free nameidata for the successful case,
175 * due to the NDINIT being done elsewhere.
178 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags,
179 struct ucred *cred, struct file *fp)
183 struct thread *td = ndp->ni_cnd.cn_thread;
185 struct vattr *vap = &vat;
190 if (fmode & O_CREAT) {
191 ndp->ni_cnd.cn_nameiop = CREATE;
193 * Set NOCACHE to avoid flushing the cache when
194 * rolling in many files at once.
196 ndp->ni_cnd.cn_flags = ISOPEN | LOCKPARENT | LOCKLEAF | NOCACHE;
197 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
198 ndp->ni_cnd.cn_flags |= FOLLOW;
199 if (!(vn_open_flags & VN_OPEN_NOAUDIT))
200 ndp->ni_cnd.cn_flags |= AUDITVNODE1;
201 if (vn_open_flags & VN_OPEN_NOCAPCHECK)
202 ndp->ni_cnd.cn_flags |= NOCAPCHECK;
204 if ((error = namei(ndp)) != 0)
206 if (ndp->ni_vp == NULL) {
209 vap->va_mode = cmode;
211 vap->va_vaflags |= VA_EXCLUSIVE;
212 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) {
213 NDFREE(ndp, NDF_ONLY_PNBUF);
215 if ((error = vn_start_write(NULL, &mp,
216 V_XSLEEP | PCATCH)) != 0)
220 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0)
221 ndp->ni_cnd.cn_flags |= MAKEENTRY;
223 error = mac_vnode_check_create(cred, ndp->ni_dvp,
227 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
230 vn_finished_write(mp);
232 NDFREE(ndp, NDF_ONLY_PNBUF);
238 if (ndp->ni_dvp == ndp->ni_vp)
244 if (fmode & O_EXCL) {
251 ndp->ni_cnd.cn_nameiop = LOOKUP;
252 ndp->ni_cnd.cn_flags = ISOPEN |
253 ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF;
254 if (!(fmode & FWRITE))
255 ndp->ni_cnd.cn_flags |= LOCKSHARED;
256 if (!(vn_open_flags & VN_OPEN_NOAUDIT))
257 ndp->ni_cnd.cn_flags |= AUDITVNODE1;
258 if (vn_open_flags & VN_OPEN_NOCAPCHECK)
259 ndp->ni_cnd.cn_flags |= NOCAPCHECK;
260 if ((error = namei(ndp)) != 0)
264 error = vn_open_vnode(vp, fmode, cred, td, fp);
270 NDFREE(ndp, NDF_ONLY_PNBUF);
278 * Common code for vnode open operations once a vnode is located.
279 * Check permissions, and call the VOP_OPEN routine.
282 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred,
283 struct thread *td, struct file *fp)
288 int error, have_flock, lock_flags, type;
290 if (vp->v_type == VLNK)
292 if (vp->v_type == VSOCK)
294 if (vp->v_type != VDIR && fmode & O_DIRECTORY)
297 if (fmode & (FWRITE | O_TRUNC)) {
298 if (vp->v_type == VDIR)
306 if ((fmode & O_APPEND) && (fmode & FWRITE))
309 error = mac_vnode_check_open(cred, vp, accmode);
313 if ((fmode & O_CREAT) == 0) {
314 if (accmode & VWRITE) {
315 error = vn_writechk(vp);
320 error = VOP_ACCESS(vp, accmode, cred, td);
325 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
326 vn_lock(vp, LK_UPGRADE | LK_RETRY);
327 if ((error = VOP_OPEN(vp, fmode, cred, td, fp)) != 0)
330 if (fmode & (O_EXLOCK | O_SHLOCK)) {
331 KASSERT(fp != NULL, ("open with flock requires fp"));
332 lock_flags = VOP_ISLOCKED(vp);
334 lf.l_whence = SEEK_SET;
337 if (fmode & O_EXLOCK)
342 if ((fmode & FNONBLOCK) == 0)
344 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type);
345 have_flock = (error == 0);
346 vn_lock(vp, lock_flags | LK_RETRY);
347 if (error == 0 && vp->v_iflag & VI_DOOMED)
350 * Another thread might have used this vnode as an
351 * executable while the vnode lock was dropped.
352 * Ensure the vnode is still able to be opened for
353 * writing after the lock has been obtained.
355 if (error == 0 && accmode & VWRITE)
356 error = vn_writechk(vp);
360 lf.l_whence = SEEK_SET;
364 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf,
367 vn_start_write(vp, &mp, V_WAIT);
368 vn_lock(vp, lock_flags | LK_RETRY);
369 (void)VOP_CLOSE(vp, fmode, cred, td);
370 vn_finished_write(mp);
371 /* Prevent second close from fdrop()->vn_close(). */
373 fp->f_ops= &badfileops;
376 fp->f_flag |= FHASLOCK;
378 if (fmode & FWRITE) {
379 VOP_ADD_WRITECOUNT(vp, 1);
380 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
381 __func__, vp, vp->v_writecount);
383 ASSERT_VOP_LOCKED(vp, "vn_open_vnode");
388 * Check for write permissions on the specified vnode.
389 * Prototype text segments cannot be written.
393 register struct vnode *vp;
396 ASSERT_VOP_LOCKED(vp, "vn_writechk");
398 * If there's shared text associated with
399 * the vnode, try to free it up once. If
400 * we fail, we can't allow writing.
412 vn_close(vp, flags, file_cred, td)
413 register struct vnode *vp;
415 struct ucred *file_cred;
419 int error, lock_flags;
421 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 &&
422 MNT_EXTENDED_SHARED(vp->v_mount))
423 lock_flags = LK_SHARED;
425 lock_flags = LK_EXCLUSIVE;
427 vn_start_write(vp, &mp, V_WAIT);
428 vn_lock(vp, lock_flags | LK_RETRY);
429 if (flags & FWRITE) {
430 VNASSERT(vp->v_writecount > 0, vp,
431 ("vn_close: negative writecount"));
432 VOP_ADD_WRITECOUNT(vp, -1);
433 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
434 __func__, vp, vp->v_writecount);
436 error = VOP_CLOSE(vp, flags, file_cred, td);
438 vn_finished_write(mp);
443 * Heuristic to detect sequential operation.
446 sequential_heuristic(struct uio *uio, struct file *fp)
449 ASSERT_VOP_LOCKED(fp->f_vnode, __func__);
450 if (fp->f_flag & FRDAHEAD)
451 return (fp->f_seqcount << IO_SEQSHIFT);
454 * Offset 0 is handled specially. open() sets f_seqcount to 1 so
455 * that the first I/O is normally considered to be slightly
456 * sequential. Seeking to offset 0 doesn't change sequentiality
457 * unless previous seeks have reduced f_seqcount to 0, in which
458 * case offset 0 is not special.
460 if ((uio->uio_offset == 0 && fp->f_seqcount > 0) ||
461 uio->uio_offset == fp->f_nextoff) {
463 * f_seqcount is in units of fixed-size blocks so that it
464 * depends mainly on the amount of sequential I/O and not
465 * much on the number of sequential I/O's. The fixed size
466 * of 16384 is hard-coded here since it is (not quite) just
467 * a magic size that works well here. This size is more
468 * closely related to the best I/O size for real disks than
469 * to any block size used by software.
471 fp->f_seqcount += howmany(uio->uio_resid, 16384);
472 if (fp->f_seqcount > IO_SEQMAX)
473 fp->f_seqcount = IO_SEQMAX;
474 return (fp->f_seqcount << IO_SEQSHIFT);
477 /* Not sequential. Quickly draw-down sequentiality. */
478 if (fp->f_seqcount > 1)
486 * Package up an I/O request on a vnode into a uio and do it.
489 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset,
490 enum uio_seg segflg, int ioflg, struct ucred *active_cred,
491 struct ucred *file_cred, ssize_t *aresid, struct thread *td)
498 struct vn_io_fault_args args;
499 int error, lock_flags;
501 auio.uio_iov = &aiov;
503 aiov.iov_base = base;
505 auio.uio_resid = len;
506 auio.uio_offset = offset;
507 auio.uio_segflg = segflg;
512 if ((ioflg & IO_NODELOCKED) == 0) {
513 if ((ioflg & IO_RANGELOCKED) == 0) {
514 if (rw == UIO_READ) {
515 rl_cookie = vn_rangelock_rlock(vp, offset,
518 rl_cookie = vn_rangelock_wlock(vp, offset,
524 if (rw == UIO_WRITE) {
525 if (vp->v_type != VCHR &&
526 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH))
529 if (MNT_SHARED_WRITES(mp) ||
530 ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount)))
531 lock_flags = LK_SHARED;
533 lock_flags = LK_EXCLUSIVE;
535 lock_flags = LK_SHARED;
536 vn_lock(vp, lock_flags | LK_RETRY);
540 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
542 if ((ioflg & IO_NOMACCHECK) == 0) {
544 error = mac_vnode_check_read(active_cred, file_cred,
547 error = mac_vnode_check_write(active_cred, file_cred,
552 if (file_cred != NULL)
556 if (do_vn_io_fault(vp, &auio)) {
557 args.kind = VN_IO_FAULT_VOP;
560 args.args.vop_args.vp = vp;
561 error = vn_io_fault1(vp, &auio, &args, td);
562 } else if (rw == UIO_READ) {
563 error = VOP_READ(vp, &auio, ioflg, cred);
564 } else /* if (rw == UIO_WRITE) */ {
565 error = VOP_WRITE(vp, &auio, ioflg, cred);
569 *aresid = auio.uio_resid;
571 if (auio.uio_resid && error == 0)
573 if ((ioflg & IO_NODELOCKED) == 0) {
576 vn_finished_write(mp);
579 if (rl_cookie != NULL)
580 vn_rangelock_unlock(vp, rl_cookie);
585 * Package up an I/O request on a vnode into a uio and do it. The I/O
586 * request is split up into smaller chunks and we try to avoid saturating
587 * the buffer cache while potentially holding a vnode locked, so we
588 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield()
589 * to give other processes a chance to lock the vnode (either other processes
590 * core'ing the same binary, or unrelated processes scanning the directory).
593 vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred,
594 file_cred, aresid, td)
602 struct ucred *active_cred;
603 struct ucred *file_cred;
614 * Force `offset' to a multiple of MAXBSIZE except possibly
615 * for the first chunk, so that filesystems only need to
616 * write full blocks except possibly for the first and last
619 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE;
623 if (rw != UIO_READ && vp->v_type == VREG)
626 error = vn_rdwr(rw, vp, base, chunk, offset, segflg,
627 ioflg, active_cred, file_cred, &iaresid, td);
628 len -= chunk; /* aresid calc already includes length */
632 base = (char *)base + chunk;
633 kern_yield(PRI_USER);
636 *aresid = len + iaresid;
641 foffset_lock(struct file *fp, int flags)
646 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
648 #if OFF_MAX <= LONG_MAX
650 * Caller only wants the current f_offset value. Assume that
651 * the long and shorter integer types reads are atomic.
653 if ((flags & FOF_NOLOCK) != 0)
654 return (fp->f_offset);
658 * According to McKusick the vn lock was protecting f_offset here.
659 * It is now protected by the FOFFSET_LOCKED flag.
661 mtxp = mtx_pool_find(mtxpool_sleep, fp);
663 if ((flags & FOF_NOLOCK) == 0) {
664 while (fp->f_vnread_flags & FOFFSET_LOCKED) {
665 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING;
666 msleep(&fp->f_vnread_flags, mtxp, PUSER -1,
669 fp->f_vnread_flags |= FOFFSET_LOCKED;
677 foffset_unlock(struct file *fp, off_t val, int flags)
681 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
683 #if OFF_MAX <= LONG_MAX
684 if ((flags & FOF_NOLOCK) != 0) {
685 if ((flags & FOF_NOUPDATE) == 0)
687 if ((flags & FOF_NEXTOFF) != 0)
693 mtxp = mtx_pool_find(mtxpool_sleep, fp);
695 if ((flags & FOF_NOUPDATE) == 0)
697 if ((flags & FOF_NEXTOFF) != 0)
699 if ((flags & FOF_NOLOCK) == 0) {
700 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0,
701 ("Lost FOFFSET_LOCKED"));
702 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING)
703 wakeup(&fp->f_vnread_flags);
704 fp->f_vnread_flags = 0;
710 foffset_lock_uio(struct file *fp, struct uio *uio, int flags)
713 if ((flags & FOF_OFFSET) == 0)
714 uio->uio_offset = foffset_lock(fp, flags);
718 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags)
721 if ((flags & FOF_OFFSET) == 0)
722 foffset_unlock(fp, uio->uio_offset, flags);
726 get_advice(struct file *fp, struct uio *uio)
731 ret = POSIX_FADV_NORMAL;
732 if (fp->f_advice == NULL)
735 mtxp = mtx_pool_find(mtxpool_sleep, fp);
737 if (uio->uio_offset >= fp->f_advice->fa_start &&
738 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end)
739 ret = fp->f_advice->fa_advice;
745 * File table vnode read routine.
748 vn_read(fp, uio, active_cred, flags, td)
751 struct ucred *active_cred;
759 off_t offset, start, end;
761 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
763 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
766 if (fp->f_flag & FNONBLOCK)
768 if (fp->f_flag & O_DIRECT)
770 advice = get_advice(fp, uio);
771 vn_lock(vp, LK_SHARED | LK_RETRY);
774 case POSIX_FADV_NORMAL:
775 case POSIX_FADV_SEQUENTIAL:
776 case POSIX_FADV_NOREUSE:
777 ioflag |= sequential_heuristic(uio, fp);
779 case POSIX_FADV_RANDOM:
780 /* Disable read-ahead for random I/O. */
783 offset = uio->uio_offset;
786 error = mac_vnode_check_read(active_cred, fp->f_cred, vp);
789 error = VOP_READ(vp, uio, ioflag, fp->f_cred);
790 fp->f_nextoff = uio->uio_offset;
792 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
793 offset != uio->uio_offset) {
795 * Use POSIX_FADV_DONTNEED to flush clean pages and
796 * buffers for the backing file after a
797 * POSIX_FADV_NOREUSE read(2). To optimize the common
798 * case of using POSIX_FADV_NOREUSE with sequential
799 * access, track the previous implicit DONTNEED
800 * request and grow this request to include the
801 * current read(2) in addition to the previous
802 * DONTNEED. With purely sequential access this will
803 * cause the DONTNEED requests to continously grow to
804 * cover all of the previously read regions of the
805 * file. This allows filesystem blocks that are
806 * accessed by multiple calls to read(2) to be flushed
807 * once the last read(2) finishes.
810 end = uio->uio_offset - 1;
811 mtxp = mtx_pool_find(mtxpool_sleep, fp);
813 if (fp->f_advice != NULL &&
814 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) {
815 if (start != 0 && fp->f_advice->fa_prevend + 1 == start)
816 start = fp->f_advice->fa_prevstart;
817 else if (fp->f_advice->fa_prevstart != 0 &&
818 fp->f_advice->fa_prevstart == end + 1)
819 end = fp->f_advice->fa_prevend;
820 fp->f_advice->fa_prevstart = start;
821 fp->f_advice->fa_prevend = end;
824 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED);
830 * File table vnode write routine.
833 vn_write(fp, uio, active_cred, flags, td)
836 struct ucred *active_cred;
843 int error, ioflag, lock_flags;
845 off_t offset, start, end;
847 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
849 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
851 if (vp->v_type == VREG)
854 if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
856 if (fp->f_flag & FNONBLOCK)
858 if (fp->f_flag & O_DIRECT)
860 if ((fp->f_flag & O_FSYNC) ||
861 (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
864 if (vp->v_type != VCHR &&
865 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
868 advice = get_advice(fp, uio);
870 if (MNT_SHARED_WRITES(mp) ||
871 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount))) {
872 lock_flags = LK_SHARED;
874 lock_flags = LK_EXCLUSIVE;
877 vn_lock(vp, lock_flags | LK_RETRY);
879 case POSIX_FADV_NORMAL:
880 case POSIX_FADV_SEQUENTIAL:
881 case POSIX_FADV_NOREUSE:
882 ioflag |= sequential_heuristic(uio, fp);
884 case POSIX_FADV_RANDOM:
885 /* XXX: Is this correct? */
888 offset = uio->uio_offset;
891 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
894 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred);
895 fp->f_nextoff = uio->uio_offset;
897 if (vp->v_type != VCHR)
898 vn_finished_write(mp);
899 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
900 offset != uio->uio_offset) {
902 * Use POSIX_FADV_DONTNEED to flush clean pages and
903 * buffers for the backing file after a
904 * POSIX_FADV_NOREUSE write(2). To optimize the
905 * common case of using POSIX_FADV_NOREUSE with
906 * sequential access, track the previous implicit
907 * DONTNEED request and grow this request to include
908 * the current write(2) in addition to the previous
909 * DONTNEED. With purely sequential access this will
910 * cause the DONTNEED requests to continously grow to
911 * cover all of the previously written regions of the
914 * Note that the blocks just written are almost
915 * certainly still dirty, so this only works when
916 * VOP_ADVISE() calls from subsequent writes push out
917 * the data written by this write(2) once the backing
918 * buffers are clean. However, as compared to forcing
919 * IO_DIRECT, this gives much saner behavior. Write
920 * clustering is still allowed, and clean pages are
921 * merely moved to the cache page queue rather than
922 * outright thrown away. This means a subsequent
923 * read(2) can still avoid hitting the disk if the
924 * pages have not been reclaimed.
926 * This does make POSIX_FADV_NOREUSE largely useless
927 * with non-sequential access. However, sequential
928 * access is the more common use case and the flag is
932 end = uio->uio_offset - 1;
933 mtxp = mtx_pool_find(mtxpool_sleep, fp);
935 if (fp->f_advice != NULL &&
936 fp->f_advice->fa_advice == POSIX_FADV_NOREUSE) {
937 if (start != 0 && fp->f_advice->fa_prevend + 1 == start)
938 start = fp->f_advice->fa_prevstart;
939 else if (fp->f_advice->fa_prevstart != 0 &&
940 fp->f_advice->fa_prevstart == end + 1)
941 end = fp->f_advice->fa_prevend;
942 fp->f_advice->fa_prevstart = start;
943 fp->f_advice->fa_prevend = end;
946 error = VOP_ADVISE(vp, start, end, POSIX_FADV_DONTNEED);
954 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to
955 * prevent the following deadlock:
957 * Assume that the thread A reads from the vnode vp1 into userspace
958 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is
959 * currently not resident, then system ends up with the call chain
960 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] ->
961 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2)
962 * which establishes lock order vp1->vn_lock, then vp2->vn_lock.
963 * If, at the same time, thread B reads from vnode vp2 into buffer buf2
964 * backed by the pages of vnode vp1, and some page in buf2 is not
965 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock.
967 * To prevent the lock order reversal and deadlock, vn_io_fault() does
968 * not allow page faults to happen during VOP_READ() or VOP_WRITE().
969 * Instead, it first tries to do the whole range i/o with pagefaults
970 * disabled. If all pages in the i/o buffer are resident and mapped,
971 * VOP will succeed (ignoring the genuine filesystem errors).
972 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do
973 * i/o in chunks, with all pages in the chunk prefaulted and held
974 * using vm_fault_quick_hold_pages().
976 * Filesystems using this deadlock avoidance scheme should use the
977 * array of the held pages from uio, saved in the curthread->td_ma,
978 * instead of doing uiomove(). A helper function
979 * vn_io_fault_uiomove() converts uiomove request into
980 * uiomove_fromphys() over td_ma array.
982 * Since vnode locks do not cover the whole i/o anymore, rangelocks
983 * make the current i/o request atomic with respect to other i/os and
988 * Decode vn_io_fault_args and perform the corresponding i/o.
991 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio,
995 switch (args->kind) {
996 case VN_IO_FAULT_FOP:
997 return ((args->args.fop_args.doio)(args->args.fop_args.fp,
998 uio, args->cred, args->flags, td));
999 case VN_IO_FAULT_VOP:
1000 if (uio->uio_rw == UIO_READ) {
1001 return (VOP_READ(args->args.vop_args.vp, uio,
1002 args->flags, args->cred));
1003 } else if (uio->uio_rw == UIO_WRITE) {
1004 return (VOP_WRITE(args->args.vop_args.vp, uio,
1005 args->flags, args->cred));
1009 panic("vn_io_fault_doio: unknown kind of io %d %d", args->kind,
1014 * Common code for vn_io_fault(), agnostic to the kind of i/o request.
1015 * Uses vn_io_fault_doio() to make the call to an actual i/o function.
1016 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request
1017 * into args and call vn_io_fault1() to handle faults during the user
1018 * mode buffer accesses.
1021 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args,
1024 vm_page_t ma[io_hold_cnt + 2];
1025 struct uio *uio_clone, short_uio;
1026 struct iovec short_iovec[1];
1027 vm_page_t *prev_td_ma;
1029 vm_offset_t addr, end;
1032 int error, cnt, save, saveheld, prev_td_ma_cnt;
1034 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ;
1037 * The UFS follows IO_UNIT directive and replays back both
1038 * uio_offset and uio_resid if an error is encountered during the
1039 * operation. But, since the iovec may be already advanced,
1040 * uio is still in an inconsistent state.
1042 * Cache a copy of the original uio, which is advanced to the redo
1043 * point using UIO_NOCOPY below.
1045 uio_clone = cloneuio(uio);
1046 resid = uio->uio_resid;
1048 short_uio.uio_segflg = UIO_USERSPACE;
1049 short_uio.uio_rw = uio->uio_rw;
1050 short_uio.uio_td = uio->uio_td;
1052 save = vm_fault_disable_pagefaults();
1053 error = vn_io_fault_doio(args, uio, td);
1054 if (error != EFAULT)
1057 atomic_add_long(&vn_io_faults_cnt, 1);
1058 uio_clone->uio_segflg = UIO_NOCOPY;
1059 uiomove(NULL, resid - uio->uio_resid, uio_clone);
1060 uio_clone->uio_segflg = uio->uio_segflg;
1062 saveheld = curthread_pflags_set(TDP_UIOHELD);
1063 prev_td_ma = td->td_ma;
1064 prev_td_ma_cnt = td->td_ma_cnt;
1066 while (uio_clone->uio_resid != 0) {
1067 len = uio_clone->uio_iov->iov_len;
1069 KASSERT(uio_clone->uio_iovcnt >= 1,
1070 ("iovcnt underflow"));
1071 uio_clone->uio_iov++;
1072 uio_clone->uio_iovcnt--;
1075 if (len > io_hold_cnt * PAGE_SIZE)
1076 len = io_hold_cnt * PAGE_SIZE;
1077 addr = (uintptr_t)uio_clone->uio_iov->iov_base;
1078 end = round_page(addr + len);
1083 cnt = atop(end - trunc_page(addr));
1085 * A perfectly misaligned address and length could cause
1086 * both the start and the end of the chunk to use partial
1087 * page. +2 accounts for such a situation.
1089 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map,
1090 addr, len, prot, ma, io_hold_cnt + 2);
1095 short_uio.uio_iov = &short_iovec[0];
1096 short_iovec[0].iov_base = (void *)addr;
1097 short_uio.uio_iovcnt = 1;
1098 short_uio.uio_resid = short_iovec[0].iov_len = len;
1099 short_uio.uio_offset = uio_clone->uio_offset;
1101 td->td_ma_cnt = cnt;
1103 error = vn_io_fault_doio(args, &short_uio, td);
1104 vm_page_unhold_pages(ma, cnt);
1105 adv = len - short_uio.uio_resid;
1107 uio_clone->uio_iov->iov_base =
1108 (char *)uio_clone->uio_iov->iov_base + adv;
1109 uio_clone->uio_iov->iov_len -= adv;
1110 uio_clone->uio_resid -= adv;
1111 uio_clone->uio_offset += adv;
1113 uio->uio_resid -= adv;
1114 uio->uio_offset += adv;
1116 if (error != 0 || adv == 0)
1119 td->td_ma = prev_td_ma;
1120 td->td_ma_cnt = prev_td_ma_cnt;
1121 curthread_pflags_restore(saveheld);
1123 vm_fault_enable_pagefaults(save);
1124 free(uio_clone, M_IOV);
1129 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred,
1130 int flags, struct thread *td)
1135 struct vn_io_fault_args args;
1138 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write;
1140 foffset_lock_uio(fp, uio, flags);
1141 if (do_vn_io_fault(vp, uio)) {
1142 args.kind = VN_IO_FAULT_FOP;
1143 args.args.fop_args.fp = fp;
1144 args.args.fop_args.doio = doio;
1145 args.cred = active_cred;
1146 args.flags = flags | FOF_OFFSET;
1147 if (uio->uio_rw == UIO_READ) {
1148 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset,
1149 uio->uio_offset + uio->uio_resid);
1150 } else if ((fp->f_flag & O_APPEND) != 0 ||
1151 (flags & FOF_OFFSET) == 0) {
1152 /* For appenders, punt and lock the whole range. */
1153 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1155 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset,
1156 uio->uio_offset + uio->uio_resid);
1158 error = vn_io_fault1(vp, uio, &args, td);
1159 vn_rangelock_unlock(vp, rl_cookie);
1161 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td);
1163 foffset_unlock_uio(fp, uio, flags);
1168 * Helper function to perform the requested uiomove operation using
1169 * the held pages for io->uio_iov[0].iov_base buffer instead of
1170 * copyin/copyout. Access to the pages with uiomove_fromphys()
1171 * instead of iov_base prevents page faults that could occur due to
1172 * pmap_collect() invalidating the mapping created by
1173 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or
1174 * object cleanup revoking the write access from page mappings.
1176 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove()
1177 * instead of plain uiomove().
1180 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio)
1182 struct uio transp_uio;
1183 struct iovec transp_iov[1];
1189 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1190 uio->uio_segflg != UIO_USERSPACE)
1191 return (uiomove(data, xfersize, uio));
1193 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1194 transp_iov[0].iov_base = data;
1195 transp_uio.uio_iov = &transp_iov[0];
1196 transp_uio.uio_iovcnt = 1;
1197 if (xfersize > uio->uio_resid)
1198 xfersize = uio->uio_resid;
1199 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize;
1200 transp_uio.uio_offset = 0;
1201 transp_uio.uio_segflg = UIO_SYSSPACE;
1203 * Since transp_iov points to data, and td_ma page array
1204 * corresponds to original uio->uio_iov, we need to invert the
1205 * direction of the i/o operation as passed to
1206 * uiomove_fromphys().
1208 switch (uio->uio_rw) {
1210 transp_uio.uio_rw = UIO_READ;
1213 transp_uio.uio_rw = UIO_WRITE;
1216 transp_uio.uio_td = uio->uio_td;
1217 error = uiomove_fromphys(td->td_ma,
1218 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK,
1219 xfersize, &transp_uio);
1220 adv = xfersize - transp_uio.uio_resid;
1222 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) -
1223 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT);
1225 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1227 td->td_ma_cnt -= pgadv;
1228 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv;
1229 uio->uio_iov->iov_len -= adv;
1230 uio->uio_resid -= adv;
1231 uio->uio_offset += adv;
1236 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize,
1240 vm_offset_t iov_base;
1244 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1245 uio->uio_segflg != UIO_USERSPACE)
1246 return (uiomove_fromphys(ma, offset, xfersize, uio));
1248 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1249 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize;
1250 iov_base = (vm_offset_t)uio->uio_iov->iov_base;
1251 switch (uio->uio_rw) {
1253 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma,
1257 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK,
1261 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT);
1263 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1265 td->td_ma_cnt -= pgadv;
1266 uio->uio_iov->iov_base = (char *)(iov_base + cnt);
1267 uio->uio_iov->iov_len -= cnt;
1268 uio->uio_resid -= cnt;
1269 uio->uio_offset += cnt;
1275 * File table truncate routine.
1278 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred,
1290 * Lock the whole range for truncation. Otherwise split i/o
1291 * might happen partly before and partly after the truncation.
1293 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1294 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
1297 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1298 if (vp->v_type == VDIR) {
1303 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
1307 error = vn_writechk(vp);
1310 vattr.va_size = length;
1311 error = VOP_SETATTR(vp, &vattr, fp->f_cred);
1315 vn_finished_write(mp);
1317 vn_rangelock_unlock(vp, rl_cookie);
1322 * File table vnode stat routine.
1325 vn_statfile(fp, sb, active_cred, td)
1328 struct ucred *active_cred;
1331 struct vnode *vp = fp->f_vnode;
1334 vn_lock(vp, LK_SHARED | LK_RETRY);
1335 error = vn_stat(vp, sb, active_cred, fp->f_cred, td);
1342 * Stat a vnode; implementation for the stat syscall
1345 vn_stat(vp, sb, active_cred, file_cred, td)
1347 register struct stat *sb;
1348 struct ucred *active_cred;
1349 struct ucred *file_cred;
1353 register struct vattr *vap;
1358 error = mac_vnode_check_stat(active_cred, file_cred, vp);
1366 * Initialize defaults for new and unusual fields, so that file
1367 * systems which don't support these fields don't need to know
1370 vap->va_birthtime.tv_sec = -1;
1371 vap->va_birthtime.tv_nsec = 0;
1372 vap->va_fsid = VNOVAL;
1373 vap->va_rdev = NODEV;
1375 error = VOP_GETATTR(vp, vap, active_cred);
1380 * Zero the spare stat fields
1382 bzero(sb, sizeof *sb);
1385 * Copy from vattr table
1387 if (vap->va_fsid != VNOVAL)
1388 sb->st_dev = vap->va_fsid;
1390 sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0];
1391 sb->st_ino = vap->va_fileid;
1392 mode = vap->va_mode;
1393 switch (vap->va_type) {
1419 sb->st_nlink = vap->va_nlink;
1420 sb->st_uid = vap->va_uid;
1421 sb->st_gid = vap->va_gid;
1422 sb->st_rdev = vap->va_rdev;
1423 if (vap->va_size > OFF_MAX)
1425 sb->st_size = vap->va_size;
1426 sb->st_atim = vap->va_atime;
1427 sb->st_mtim = vap->va_mtime;
1428 sb->st_ctim = vap->va_ctime;
1429 sb->st_birthtim = vap->va_birthtime;
1432 * According to www.opengroup.org, the meaning of st_blksize is
1433 * "a filesystem-specific preferred I/O block size for this
1434 * object. In some filesystem types, this may vary from file
1436 * Use miminum/default of PAGE_SIZE (e.g. for VCHR).
1439 sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize);
1441 sb->st_flags = vap->va_flags;
1442 if (priv_check(td, PRIV_VFS_GENERATION))
1445 sb->st_gen = vap->va_gen;
1447 sb->st_blocks = vap->va_bytes / S_BLKSIZE;
1452 * File table vnode ioctl routine.
1455 vn_ioctl(fp, com, data, active_cred, td)
1459 struct ucred *active_cred;
1467 switch (vp->v_type) {
1472 vn_lock(vp, LK_SHARED | LK_RETRY);
1473 error = VOP_GETATTR(vp, &vattr, active_cred);
1476 *(int *)data = vattr.va_size - fp->f_offset;
1482 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1491 * File table vnode poll routine.
1494 vn_poll(fp, events, active_cred, td)
1497 struct ucred *active_cred;
1505 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1506 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp);
1511 error = VOP_POLL(vp, events, fp->f_cred, td);
1516 * Acquire the requested lock and then check for validity. LK_RETRY
1517 * permits vn_lock to return doomed vnodes.
1520 _vn_lock(struct vnode *vp, int flags, char *file, int line)
1524 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
1525 ("vn_lock called with no locktype."));
1527 #ifdef DEBUG_VFS_LOCKS
1528 KASSERT(vp->v_holdcnt != 0,
1529 ("vn_lock %p: zero hold count", vp));
1531 error = VOP_LOCK1(vp, flags, file, line);
1532 flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */
1533 KASSERT((flags & LK_RETRY) == 0 || error == 0,
1534 ("LK_RETRY set with incompatible flags (0x%x) or an error occured (%d)",
1537 * Callers specify LK_RETRY if they wish to get dead vnodes.
1538 * If RETRY is not set, we return ENOENT instead.
1540 if (error == 0 && vp->v_iflag & VI_DOOMED &&
1541 (flags & LK_RETRY) == 0) {
1546 } while (flags & LK_RETRY && error != 0);
1551 * File table vnode close routine.
1554 vn_closefile(fp, td)
1563 fp->f_ops = &badfileops;
1565 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK)
1568 error = vn_close(vp, fp->f_flag, fp->f_cred, td);
1570 if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) {
1571 lf.l_whence = SEEK_SET;
1574 lf.l_type = F_UNLCK;
1575 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK);
1582 vn_suspendable_mp(struct mount *mp)
1585 return ((mp->mnt_kern_flag & MNTK_SUSPENDABLE) != 0);
1589 vn_suspendable(struct vnode *vp, struct mount **mpp)
1597 return (vn_suspendable_mp(*mpp));
1601 * Preparing to start a filesystem write operation. If the operation is
1602 * permitted, then we bump the count of operations in progress and
1603 * proceed. If a suspend request is in progress, we wait until the
1604 * suspension is over, and then proceed.
1607 vn_start_write_locked(struct mount *mp, int flags)
1611 mtx_assert(MNT_MTX(mp), MA_OWNED);
1615 * Check on status of suspension.
1617 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 ||
1618 mp->mnt_susp_owner != curthread) {
1619 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ?
1620 (flags & PCATCH) : 0) | (PUSER - 1);
1621 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1622 if (flags & V_NOWAIT) {
1623 error = EWOULDBLOCK;
1626 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags,
1632 if (flags & V_XSLEEP)
1634 mp->mnt_writeopcount++;
1636 if (error != 0 || (flags & V_XSLEEP) != 0)
1643 vn_start_write(vp, mpp, flags)
1651 if (!vn_suspendable(vp, mpp))
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)
1671 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1673 * As long as a vnode is not provided we need to acquire a
1674 * refcount for the provided mountpoint too, in order to
1675 * emulate a vfs_ref().
1681 return (vn_start_write_locked(mp, flags));
1685 * Secondary suspension. Used by operations such as vop_inactive
1686 * routines that are needed by the higher level functions. These
1687 * are allowed to proceed until all the higher level functions have
1688 * completed (indicated by mnt_writeopcount dropping to zero). At that
1689 * time, these operations are halted until the suspension is over.
1692 vn_start_secondary_write(vp, mpp, flags)
1700 if (!vn_suspendable(vp, mpp))
1705 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1707 if (error != EOPNOTSUPP)
1713 * If we are not suspended or have not yet reached suspended
1714 * mode, then let the operation proceed.
1716 if ((mp = *mpp) == NULL)
1720 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1722 * As long as a vnode is not provided we need to acquire a
1723 * refcount for the provided mountpoint too, in order to
1724 * emulate a vfs_ref().
1729 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) {
1730 mp->mnt_secondary_writes++;
1731 mp->mnt_secondary_accwrites++;
1735 if (flags & V_NOWAIT) {
1738 return (EWOULDBLOCK);
1741 * Wait for the suspension to finish.
1743 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP |
1744 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0),
1753 * Filesystem write operation has completed. If we are suspending and this
1754 * operation is the last one, notify the suspender that the suspension is
1758 vn_finished_write(mp)
1761 if (mp == NULL || !vn_suspendable_mp(mp))
1765 mp->mnt_writeopcount--;
1766 if (mp->mnt_writeopcount < 0)
1767 panic("vn_finished_write: neg cnt");
1768 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
1769 mp->mnt_writeopcount <= 0)
1770 wakeup(&mp->mnt_writeopcount);
1776 * Filesystem secondary write operation has completed. If we are
1777 * suspending and this operation is the last one, notify the suspender
1778 * that the suspension is now in effect.
1781 vn_finished_secondary_write(mp)
1784 if (mp == NULL || !vn_suspendable_mp(mp))
1788 mp->mnt_secondary_writes--;
1789 if (mp->mnt_secondary_writes < 0)
1790 panic("vn_finished_secondary_write: neg cnt");
1791 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
1792 mp->mnt_secondary_writes <= 0)
1793 wakeup(&mp->mnt_secondary_writes);
1800 * Request a filesystem to suspend write operations.
1803 vfs_write_suspend(struct mount *mp, int flags)
1807 MPASS(vn_suspendable_mp(mp));
1810 if (mp->mnt_susp_owner == curthread) {
1814 while (mp->mnt_kern_flag & MNTK_SUSPEND)
1815 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0);
1818 * Unmount holds a write reference on the mount point. If we
1819 * own busy reference and drain for writers, we deadlock with
1820 * the reference draining in the unmount path. Callers of
1821 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if
1822 * vfs_busy() reference is owned and caller is not in the
1825 if ((flags & VS_SKIP_UNMOUNT) != 0 &&
1826 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) {
1831 mp->mnt_kern_flag |= MNTK_SUSPEND;
1832 mp->mnt_susp_owner = curthread;
1833 if (mp->mnt_writeopcount > 0)
1834 (void) msleep(&mp->mnt_writeopcount,
1835 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0);
1838 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0)
1839 vfs_write_resume(mp, 0);
1844 * Request a filesystem to resume write operations.
1847 vfs_write_resume(struct mount *mp, int flags)
1850 MPASS(vn_suspendable_mp(mp));
1853 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1854 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner"));
1855 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 |
1857 mp->mnt_susp_owner = NULL;
1858 wakeup(&mp->mnt_writeopcount);
1859 wakeup(&mp->mnt_flag);
1860 curthread->td_pflags &= ~TDP_IGNSUSP;
1861 if ((flags & VR_START_WRITE) != 0) {
1863 mp->mnt_writeopcount++;
1866 if ((flags & VR_NO_SUSPCLR) == 0)
1868 } else if ((flags & VR_START_WRITE) != 0) {
1870 vn_start_write_locked(mp, 0);
1877 * Helper loop around vfs_write_suspend() for filesystem unmount VFS
1881 vfs_write_suspend_umnt(struct mount *mp)
1885 MPASS(vn_suspendable_mp(mp));
1886 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0,
1887 ("vfs_write_suspend_umnt: recursed"));
1889 /* dounmount() already called vn_start_write(). */
1891 vn_finished_write(mp);
1892 error = vfs_write_suspend(mp, 0);
1894 vn_start_write(NULL, &mp, V_WAIT);
1898 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0)
1901 vn_start_write(NULL, &mp, V_WAIT);
1903 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2);
1904 wakeup(&mp->mnt_flag);
1906 curthread->td_pflags |= TDP_IGNSUSP;
1911 * Implement kqueues for files by translating it to vnode operation.
1914 vn_kqfilter(struct file *fp, struct knote *kn)
1917 return (VOP_KQFILTER(fp->f_vnode, kn));
1921 * Simplified in-kernel wrapper calls for extended attribute access.
1922 * Both calls pass in a NULL credential, authorizing as "kernel" access.
1923 * Set IO_NODELOCKED in ioflg if the vnode is already locked.
1926 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace,
1927 const char *attrname, int *buflen, char *buf, struct thread *td)
1933 iov.iov_len = *buflen;
1936 auio.uio_iov = &iov;
1937 auio.uio_iovcnt = 1;
1938 auio.uio_rw = UIO_READ;
1939 auio.uio_segflg = UIO_SYSSPACE;
1941 auio.uio_offset = 0;
1942 auio.uio_resid = *buflen;
1944 if ((ioflg & IO_NODELOCKED) == 0)
1945 vn_lock(vp, LK_SHARED | LK_RETRY);
1947 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
1949 /* authorize attribute retrieval as kernel */
1950 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL,
1953 if ((ioflg & IO_NODELOCKED) == 0)
1957 *buflen = *buflen - auio.uio_resid;
1964 * XXX failure mode if partially written?
1967 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace,
1968 const char *attrname, int buflen, char *buf, struct thread *td)
1975 iov.iov_len = buflen;
1978 auio.uio_iov = &iov;
1979 auio.uio_iovcnt = 1;
1980 auio.uio_rw = UIO_WRITE;
1981 auio.uio_segflg = UIO_SYSSPACE;
1983 auio.uio_offset = 0;
1984 auio.uio_resid = buflen;
1986 if ((ioflg & IO_NODELOCKED) == 0) {
1987 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
1989 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1992 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
1994 /* authorize attribute setting as kernel */
1995 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td);
1997 if ((ioflg & IO_NODELOCKED) == 0) {
1998 vn_finished_write(mp);
2006 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace,
2007 const char *attrname, struct thread *td)
2012 if ((ioflg & IO_NODELOCKED) == 0) {
2013 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2015 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2018 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2020 /* authorize attribute removal as kernel */
2021 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td);
2022 if (error == EOPNOTSUPP)
2023 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL,
2026 if ((ioflg & IO_NODELOCKED) == 0) {
2027 vn_finished_write(mp);
2035 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags,
2039 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp));
2043 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp)
2046 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino,
2051 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg,
2052 int lkflags, struct vnode **rvp)
2057 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get");
2059 ltype = VOP_ISLOCKED(vp);
2060 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED,
2061 ("vn_vget_ino: vp not locked"));
2062 error = vfs_busy(mp, MBF_NOWAIT);
2066 error = vfs_busy(mp, 0);
2067 vn_lock(vp, ltype | LK_RETRY);
2071 if (vp->v_iflag & VI_DOOMED) {
2077 error = alloc(mp, alloc_arg, lkflags, rvp);
2080 vn_lock(vp, ltype | LK_RETRY);
2081 if (vp->v_iflag & VI_DOOMED) {
2094 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio,
2095 const struct thread *td)
2098 if (vp->v_type != VREG || td == NULL)
2100 PROC_LOCK(td->td_proc);
2101 if ((uoff_t)uio->uio_offset + uio->uio_resid >
2102 lim_cur(td->td_proc, RLIMIT_FSIZE)) {
2103 kern_psignal(td->td_proc, SIGXFSZ);
2104 PROC_UNLOCK(td->td_proc);
2107 PROC_UNLOCK(td->td_proc);
2112 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
2119 vn_lock(vp, LK_SHARED | LK_RETRY);
2120 AUDIT_ARG_VNODE1(vp);
2123 return (setfmode(td, active_cred, vp, mode));
2127 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
2134 vn_lock(vp, LK_SHARED | LK_RETRY);
2135 AUDIT_ARG_VNODE1(vp);
2138 return (setfown(td, active_cred, vp, uid, gid));
2142 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end)
2146 if ((object = vp->v_object) == NULL)
2148 VM_OBJECT_WLOCK(object);
2149 vm_object_page_remove(object, start, end, 0);
2150 VM_OBJECT_WUNLOCK(object);
2154 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred)
2162 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
2163 ("Wrong command %lu", cmd));
2165 if (vn_lock(vp, LK_SHARED) != 0)
2167 if (vp->v_type != VREG) {
2171 error = VOP_GETATTR(vp, &va, cred);
2175 if (noff >= va.va_size) {
2179 bsize = vp->v_mount->mnt_stat.f_iosize;
2180 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize) {
2181 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL);
2182 if (error == EOPNOTSUPP) {
2186 if ((bnp == -1 && cmd == FIOSEEKHOLE) ||
2187 (bnp != -1 && cmd == FIOSEEKDATA)) {
2194 if (noff > va.va_size)
2196 /* noff == va.va_size. There is an implicit hole at the end of file. */
2197 if (cmd == FIOSEEKDATA)
2207 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td)
2212 off_t foffset, size;
2215 cred = td->td_ucred;
2217 foffset = foffset_lock(fp, 0);
2218 noneg = (vp->v_type != VCHR);
2224 (offset > 0 && foffset > OFF_MAX - offset))) {
2231 vn_lock(vp, LK_SHARED | LK_RETRY);
2232 error = VOP_GETATTR(vp, &vattr, cred);
2238 * If the file references a disk device, then fetch
2239 * the media size and use that to determine the ending
2242 if (vattr.va_size == 0 && vp->v_type == VCHR &&
2243 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0)
2244 vattr.va_size = size;
2246 (vattr.va_size > OFF_MAX ||
2247 (offset > 0 && vattr.va_size > OFF_MAX - offset))) {
2251 offset += vattr.va_size;
2256 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td);
2259 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td);
2264 if (error == 0 && noneg && offset < 0)
2268 VFS_KNOTE_UNLOCKED(vp, 0);
2269 td->td_uretoff.tdu_off = offset;
2271 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0);
2276 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred,
2282 * Grant permission if the caller is the owner of the file, or
2283 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on
2284 * on the file. If the time pointer is null, then write
2285 * permission on the file is also sufficient.
2287 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes:
2288 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES
2289 * will be allowed to set the times [..] to the current
2292 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td);
2293 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0)
2294 error = VOP_ACCESS(vp, VWRITE, cred, td);
2299 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
2304 if (fp->f_type == DTYPE_FIFO)
2305 kif->kf_type = KF_TYPE_FIFO;
2307 kif->kf_type = KF_TYPE_VNODE;
2310 FILEDESC_SUNLOCK(fdp);
2311 error = vn_fill_kinfo_vnode(vp, kif);
2313 FILEDESC_SLOCK(fdp);
2318 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif)
2321 char *fullpath, *freepath;
2324 kif->kf_vnode_type = vntype_to_kinfo(vp->v_type);
2327 error = vn_fullpath(curthread, vp, &fullpath, &freepath);
2329 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
2331 if (freepath != NULL)
2332 free(freepath, M_TEMP);
2335 * Retrieve vnode attributes.
2337 va.va_fsid = VNOVAL;
2339 vn_lock(vp, LK_SHARED | LK_RETRY);
2340 error = VOP_GETATTR(vp, &va, curthread->td_ucred);
2344 if (va.va_fsid != VNOVAL)
2345 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid;
2347 kif->kf_un.kf_file.kf_file_fsid =
2348 vp->v_mount->mnt_stat.f_fsid.val[0];
2349 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid;
2350 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode);
2351 kif->kf_un.kf_file.kf_file_size = va.va_size;
2352 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev;