2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1982, 1986, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
12 * Copyright (c) 2012 Konstantin Belousov <kib@FreeBSD.org>
13 * Copyright (c) 2013, 2014 The FreeBSD Foundation
15 * Portions of this software were developed by Konstantin Belousov
16 * under sponsorship from the FreeBSD Foundation.
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted provided that the following conditions
21 * 1. Redistributions of source code must retain the above copyright
22 * notice, this list of conditions and the following disclaimer.
23 * 2. Redistributions in binary form must reproduce the above copyright
24 * notice, this list of conditions and the following disclaimer in the
25 * documentation and/or other materials provided with the distribution.
26 * 3. Neither the name of the University nor the names of its contributors
27 * may be used to endorse or promote products derived from this software
28 * without specific prior written permission.
30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
42 * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
48 #include "opt_hwpmc_hooks.h"
50 #include <sys/param.h>
51 #include <sys/systm.h>
54 #include <sys/fcntl.h>
61 #include <sys/limits.h>
64 #include <sys/mount.h>
65 #include <sys/mutex.h>
66 #include <sys/namei.h>
67 #include <sys/vnode.h>
70 #include <sys/filio.h>
71 #include <sys/resourcevar.h>
72 #include <sys/rwlock.h>
75 #include <sys/sleepqueue.h>
76 #include <sys/sysctl.h>
77 #include <sys/ttycom.h>
79 #include <sys/syslog.h>
80 #include <sys/unistd.h>
82 #include <sys/ktrace.h>
84 #include <security/audit/audit.h>
85 #include <security/mac/mac_framework.h>
88 #include <vm/vm_extern.h>
90 #include <vm/vm_map.h>
91 #include <vm/vm_object.h>
92 #include <vm/vm_page.h>
93 #include <vm/vm_pager.h>
96 #include <sys/pmckern.h>
99 static fo_rdwr_t vn_read;
100 static fo_rdwr_t vn_write;
101 static fo_rdwr_t vn_io_fault;
102 static fo_truncate_t vn_truncate;
103 static fo_ioctl_t vn_ioctl;
104 static fo_poll_t vn_poll;
105 static fo_kqfilter_t vn_kqfilter;
106 static fo_close_t vn_closefile;
107 static fo_mmap_t vn_mmap;
108 static fo_fallocate_t vn_fallocate;
109 static fo_fspacectl_t vn_fspacectl;
111 struct fileops vnops = {
112 .fo_read = vn_io_fault,
113 .fo_write = vn_io_fault,
114 .fo_truncate = vn_truncate,
115 .fo_ioctl = vn_ioctl,
117 .fo_kqfilter = vn_kqfilter,
118 .fo_stat = vn_statfile,
119 .fo_close = vn_closefile,
120 .fo_chmod = vn_chmod,
121 .fo_chown = vn_chown,
122 .fo_sendfile = vn_sendfile,
124 .fo_fill_kinfo = vn_fill_kinfo,
126 .fo_fallocate = vn_fallocate,
127 .fo_fspacectl = vn_fspacectl,
128 .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE
131 const u_int io_hold_cnt = 16;
132 static int vn_io_fault_enable = 1;
133 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_enable, CTLFLAG_RWTUN,
134 &vn_io_fault_enable, 0, "Enable vn_io_fault lock avoidance");
135 static int vn_io_fault_prefault = 0;
136 SYSCTL_INT(_debug, OID_AUTO, vn_io_fault_prefault, CTLFLAG_RWTUN,
137 &vn_io_fault_prefault, 0, "Enable vn_io_fault prefaulting");
138 static int vn_io_pgcache_read_enable = 1;
139 SYSCTL_INT(_debug, OID_AUTO, vn_io_pgcache_read_enable, CTLFLAG_RWTUN,
140 &vn_io_pgcache_read_enable, 0,
141 "Enable copying from page cache for reads, avoiding fs");
142 static u_long vn_io_faults_cnt;
143 SYSCTL_ULONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD,
144 &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers");
146 static int vfs_allow_read_dir = 0;
147 SYSCTL_INT(_security_bsd, OID_AUTO, allow_read_dir, CTLFLAG_RW,
148 &vfs_allow_read_dir, 0,
149 "Enable read(2) of directory by root for filesystems that support it");
152 * Returns true if vn_io_fault mode of handling the i/o request should
156 do_vn_io_fault(struct vnode *vp, struct uio *uio)
160 return (uio->uio_segflg == UIO_USERSPACE && vp->v_type == VREG &&
161 (mp = vp->v_mount) != NULL &&
162 (mp->mnt_kern_flag & MNTK_NO_IOPF) != 0 && vn_io_fault_enable);
166 * Structure used to pass arguments to vn_io_fault1(), to do either
167 * file- or vnode-based I/O calls.
169 struct vn_io_fault_args {
177 struct fop_args_tag {
181 struct vop_args_tag {
187 static int vn_io_fault1(struct vnode *vp, struct uio *uio,
188 struct vn_io_fault_args *args, struct thread *td);
191 vn_open(struct nameidata *ndp, int *flagp, int cmode, struct file *fp)
193 struct thread *td = ndp->ni_cnd.cn_thread;
195 return (vn_open_cred(ndp, flagp, cmode, 0, td->td_ucred, fp));
199 open2nameif(int fmode, u_int vn_open_flags)
203 res = ISOPEN | LOCKLEAF;
204 if ((fmode & O_RESOLVE_BENEATH) != 0)
206 if ((fmode & O_EMPTY_PATH) != 0)
208 if ((fmode & FREAD) != 0)
210 if ((fmode & FWRITE) != 0)
212 if ((vn_open_flags & VN_OPEN_NOAUDIT) == 0)
214 if ((vn_open_flags & VN_OPEN_NOCAPCHECK) != 0)
220 * Common code for vnode open operations via a name lookup.
221 * Lookup the vnode and invoke VOP_CREATE if needed.
222 * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
224 * Note that this does NOT free nameidata for the successful case,
225 * due to the NDINIT being done elsewhere.
228 vn_open_cred(struct nameidata *ndp, int *flagp, int cmode, u_int vn_open_flags,
229 struct ucred *cred, struct file *fp)
233 struct thread *td = ndp->ni_cnd.cn_thread;
235 struct vattr *vap = &vat;
242 if ((fmode & (O_CREAT | O_EXCL | O_DIRECTORY)) == (O_CREAT |
243 O_EXCL | O_DIRECTORY) ||
244 (fmode & (O_CREAT | O_EMPTY_PATH)) == (O_CREAT | O_EMPTY_PATH))
246 else if ((fmode & (O_CREAT | O_DIRECTORY)) == O_CREAT) {
247 ndp->ni_cnd.cn_nameiop = CREATE;
248 ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags);
250 * Set NOCACHE to avoid flushing the cache when
251 * rolling in many files at once.
253 * Set NC_KEEPPOSENTRY to keep positive entries if they already
254 * exist despite NOCACHE.
256 ndp->ni_cnd.cn_flags |= LOCKPARENT | NOCACHE | NC_KEEPPOSENTRY;
257 if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
258 ndp->ni_cnd.cn_flags |= FOLLOW;
259 if ((vn_open_flags & VN_OPEN_INVFS) == 0)
261 if ((error = namei(ndp)) != 0)
263 if (ndp->ni_vp == NULL) {
266 vap->va_mode = cmode;
268 vap->va_vaflags |= VA_EXCLUSIVE;
269 if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) {
270 NDFREE(ndp, NDF_ONLY_PNBUF);
272 if ((error = vn_start_write(NULL, &mp,
273 V_XSLEEP | PCATCH)) != 0)
278 if ((vn_open_flags & VN_OPEN_NAMECACHE) != 0)
279 ndp->ni_cnd.cn_flags |= MAKEENTRY;
281 error = mac_vnode_check_create(cred, ndp->ni_dvp,
285 error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
288 if (error == 0 && (fmode & O_EXCL) != 0 &&
289 (fmode & (O_EXLOCK | O_SHLOCK)) != 0) {
291 vp->v_iflag |= VI_FOPENING;
295 VOP_VPUT_PAIR(ndp->ni_dvp, error == 0 ? &vp : NULL,
297 vn_finished_write(mp);
299 NDFREE(ndp, NDF_ONLY_PNBUF);
300 if (error == ERELOOKUP) {
308 if (ndp->ni_dvp == ndp->ni_vp)
314 if (fmode & O_EXCL) {
318 if (vp->v_type == VDIR) {
325 ndp->ni_cnd.cn_nameiop = LOOKUP;
326 ndp->ni_cnd.cn_flags = open2nameif(fmode, vn_open_flags);
327 ndp->ni_cnd.cn_flags |= (fmode & O_NOFOLLOW) != 0 ? NOFOLLOW :
329 if ((fmode & FWRITE) == 0)
330 ndp->ni_cnd.cn_flags |= LOCKSHARED;
331 if ((error = namei(ndp)) != 0)
335 error = vn_open_vnode(vp, fmode, cred, td, fp);
338 vp->v_iflag &= ~VI_FOPENING;
347 NDFREE(ndp, NDF_ONLY_PNBUF);
355 vn_open_vnode_advlock(struct vnode *vp, int fmode, struct file *fp)
358 int error, lock_flags, type;
360 ASSERT_VOP_LOCKED(vp, "vn_open_vnode_advlock");
361 if ((fmode & (O_EXLOCK | O_SHLOCK)) == 0)
363 KASSERT(fp != NULL, ("open with flock requires fp"));
364 if (fp->f_type != DTYPE_NONE && fp->f_type != DTYPE_VNODE)
367 lock_flags = VOP_ISLOCKED(vp);
370 lf.l_whence = SEEK_SET;
373 lf.l_type = (fmode & O_EXLOCK) != 0 ? F_WRLCK : F_RDLCK;
375 if ((fmode & FNONBLOCK) == 0)
377 if ((fmode & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
379 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type);
381 fp->f_flag |= FHASLOCK;
383 vn_lock(vp, lock_flags | LK_RETRY);
388 * Common code for vnode open operations once a vnode is located.
389 * Check permissions, and call the VOP_OPEN routine.
392 vn_open_vnode(struct vnode *vp, int fmode, struct ucred *cred,
393 struct thread *td, struct file *fp)
398 if (vp->v_type == VLNK) {
399 if ((fmode & O_PATH) == 0 || (fmode & FEXEC) != 0)
402 if (vp->v_type == VSOCK)
404 if (vp->v_type != VDIR && fmode & O_DIRECTORY)
408 if ((fmode & O_PATH) == 0) {
409 if ((fmode & (FWRITE | O_TRUNC)) != 0) {
410 if (vp->v_type == VDIR)
414 if ((fmode & FREAD) != 0)
416 if ((fmode & O_APPEND) && (fmode & FWRITE))
419 if ((fmode & O_CREAT) != 0)
423 if ((fmode & FEXEC) != 0)
426 if ((fmode & O_VERIFY) != 0)
428 error = mac_vnode_check_open(cred, vp, accmode);
432 accmode &= ~(VCREAT | VVERIFY);
434 if ((fmode & O_CREAT) == 0 && accmode != 0) {
435 error = VOP_ACCESS(vp, accmode, cred, td);
439 if ((fmode & O_PATH) != 0) {
440 if (vp->v_type == VFIFO)
443 error = VOP_ACCESS(vp, VREAD, cred, td);
445 fp->f_flag |= FKQALLOWED;
449 if (vp->v_type == VFIFO && VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
450 vn_lock(vp, LK_UPGRADE | LK_RETRY);
451 error = VOP_OPEN(vp, fmode, cred, td, fp);
455 error = vn_open_vnode_advlock(vp, fmode, fp);
456 if (error == 0 && (fmode & FWRITE) != 0) {
457 error = VOP_ADD_WRITECOUNT(vp, 1);
459 CTR3(KTR_VFS, "%s: vp %p v_writecount increased to %d",
460 __func__, vp, vp->v_writecount);
465 * Error from advlock or VOP_ADD_WRITECOUNT() still requires
466 * calling VOP_CLOSE() to pair with earlier VOP_OPEN().
471 * Arrange the call by having fdrop() to use
472 * vn_closefile(). This is to satisfy
473 * filesystems like devfs or tmpfs, which
474 * override fo_close().
476 fp->f_flag |= FOPENFAILED;
478 if (fp->f_ops == &badfileops) {
479 fp->f_type = DTYPE_VNODE;
485 * If there is no fp, due to kernel-mode open,
486 * we can call VOP_CLOSE() now.
488 if (vp->v_type != VFIFO && (fmode & FWRITE) != 0 &&
489 !MNT_EXTENDED_SHARED(vp->v_mount) &&
490 VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
491 vn_lock(vp, LK_UPGRADE | LK_RETRY);
492 (void)VOP_CLOSE(vp, fmode & (FREAD | FWRITE | FEXEC),
497 ASSERT_VOP_LOCKED(vp, "vn_open_vnode");
503 * Check for write permissions on the specified vnode.
504 * Prototype text segments cannot be written.
508 vn_writechk(struct vnode *vp)
511 ASSERT_VOP_LOCKED(vp, "vn_writechk");
513 * If there's shared text associated with
514 * the vnode, try to free it up once. If
515 * we fail, we can't allow writing.
527 vn_close1(struct vnode *vp, int flags, struct ucred *file_cred,
528 struct thread *td, bool keep_ref)
531 int error, lock_flags;
533 if (vp->v_type != VFIFO && (flags & FWRITE) == 0 &&
534 MNT_EXTENDED_SHARED(vp->v_mount))
535 lock_flags = LK_SHARED;
537 lock_flags = LK_EXCLUSIVE;
539 vn_start_write(vp, &mp, V_WAIT);
540 vn_lock(vp, lock_flags | LK_RETRY);
541 AUDIT_ARG_VNODE1(vp);
542 if ((flags & (FWRITE | FOPENFAILED)) == FWRITE) {
543 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
544 CTR3(KTR_VFS, "%s: vp %p v_writecount decreased to %d",
545 __func__, vp, vp->v_writecount);
547 error = VOP_CLOSE(vp, flags, file_cred, td);
552 vn_finished_write(mp);
557 vn_close(struct vnode *vp, int flags, struct ucred *file_cred,
561 return (vn_close1(vp, flags, file_cred, td, false));
565 * Heuristic to detect sequential operation.
568 sequential_heuristic(struct uio *uio, struct file *fp)
572 ASSERT_VOP_LOCKED(fp->f_vnode, __func__);
575 if (fp->f_flag & FRDAHEAD)
576 return (fp->f_seqcount[rw] << IO_SEQSHIFT);
579 * Offset 0 is handled specially. open() sets f_seqcount to 1 so
580 * that the first I/O is normally considered to be slightly
581 * sequential. Seeking to offset 0 doesn't change sequentiality
582 * unless previous seeks have reduced f_seqcount to 0, in which
583 * case offset 0 is not special.
585 if ((uio->uio_offset == 0 && fp->f_seqcount[rw] > 0) ||
586 uio->uio_offset == fp->f_nextoff[rw]) {
588 * f_seqcount is in units of fixed-size blocks so that it
589 * depends mainly on the amount of sequential I/O and not
590 * much on the number of sequential I/O's. The fixed size
591 * of 16384 is hard-coded here since it is (not quite) just
592 * a magic size that works well here. This size is more
593 * closely related to the best I/O size for real disks than
594 * to any block size used by software.
596 if (uio->uio_resid >= IO_SEQMAX * 16384)
597 fp->f_seqcount[rw] = IO_SEQMAX;
599 fp->f_seqcount[rw] += howmany(uio->uio_resid, 16384);
600 if (fp->f_seqcount[rw] > IO_SEQMAX)
601 fp->f_seqcount[rw] = IO_SEQMAX;
603 return (fp->f_seqcount[rw] << IO_SEQSHIFT);
606 /* Not sequential. Quickly draw-down sequentiality. */
607 if (fp->f_seqcount[rw] > 1)
608 fp->f_seqcount[rw] = 1;
610 fp->f_seqcount[rw] = 0;
615 * Package up an I/O request on a vnode into a uio and do it.
618 vn_rdwr(enum uio_rw rw, struct vnode *vp, void *base, int len, off_t offset,
619 enum uio_seg segflg, int ioflg, struct ucred *active_cred,
620 struct ucred *file_cred, ssize_t *aresid, struct thread *td)
627 struct vn_io_fault_args args;
628 int error, lock_flags;
630 if (offset < 0 && vp->v_type != VCHR)
632 auio.uio_iov = &aiov;
634 aiov.iov_base = base;
636 auio.uio_resid = len;
637 auio.uio_offset = offset;
638 auio.uio_segflg = segflg;
643 if ((ioflg & IO_NODELOCKED) == 0) {
644 if ((ioflg & IO_RANGELOCKED) == 0) {
645 if (rw == UIO_READ) {
646 rl_cookie = vn_rangelock_rlock(vp, offset,
648 } else if ((ioflg & IO_APPEND) != 0) {
649 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
651 rl_cookie = vn_rangelock_wlock(vp, offset,
657 if (rw == UIO_WRITE) {
658 if (vp->v_type != VCHR &&
659 (error = vn_start_write(vp, &mp, V_WAIT | PCATCH))
662 lock_flags = vn_lktype_write(mp, vp);
664 lock_flags = LK_SHARED;
665 vn_lock(vp, lock_flags | LK_RETRY);
669 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
671 if ((ioflg & IO_NOMACCHECK) == 0) {
673 error = mac_vnode_check_read(active_cred, file_cred,
676 error = mac_vnode_check_write(active_cred, file_cred,
681 if (file_cred != NULL)
685 if (do_vn_io_fault(vp, &auio)) {
686 args.kind = VN_IO_FAULT_VOP;
689 args.args.vop_args.vp = vp;
690 error = vn_io_fault1(vp, &auio, &args, td);
691 } else if (rw == UIO_READ) {
692 error = VOP_READ(vp, &auio, ioflg, cred);
693 } else /* if (rw == UIO_WRITE) */ {
694 error = VOP_WRITE(vp, &auio, ioflg, cred);
698 *aresid = auio.uio_resid;
700 if (auio.uio_resid && error == 0)
702 if ((ioflg & IO_NODELOCKED) == 0) {
705 vn_finished_write(mp);
708 if (rl_cookie != NULL)
709 vn_rangelock_unlock(vp, rl_cookie);
714 * Package up an I/O request on a vnode into a uio and do it. The I/O
715 * request is split up into smaller chunks and we try to avoid saturating
716 * the buffer cache while potentially holding a vnode locked, so we
717 * check bwillwrite() before calling vn_rdwr(). We also call kern_yield()
718 * to give other processes a chance to lock the vnode (either other processes
719 * core'ing the same binary, or unrelated processes scanning the directory).
722 vn_rdwr_inchunks(enum uio_rw rw, struct vnode *vp, void *base, size_t len,
723 off_t offset, enum uio_seg segflg, int ioflg, struct ucred *active_cred,
724 struct ucred *file_cred, size_t *aresid, struct thread *td)
733 * Force `offset' to a multiple of MAXBSIZE except possibly
734 * for the first chunk, so that filesystems only need to
735 * write full blocks except possibly for the first and last
738 chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE;
742 if (rw != UIO_READ && vp->v_type == VREG)
745 error = vn_rdwr(rw, vp, base, chunk, offset, segflg,
746 ioflg, active_cred, file_cred, &iaresid, td);
747 len -= chunk; /* aresid calc already includes length */
751 base = (char *)base + chunk;
752 kern_yield(PRI_USER);
755 *aresid = len + iaresid;
759 #if OFF_MAX <= LONG_MAX
761 foffset_lock(struct file *fp, int flags)
763 volatile short *flagsp;
767 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
769 if ((flags & FOF_NOLOCK) != 0)
770 return (atomic_load_long(&fp->f_offset));
773 * According to McKusick the vn lock was protecting f_offset here.
774 * It is now protected by the FOFFSET_LOCKED flag.
776 flagsp = &fp->f_vnread_flags;
777 if (atomic_cmpset_acq_16(flagsp, 0, FOFFSET_LOCKED))
778 return (atomic_load_long(&fp->f_offset));
780 sleepq_lock(&fp->f_vnread_flags);
781 state = atomic_load_16(flagsp);
783 if ((state & FOFFSET_LOCKED) == 0) {
784 if (!atomic_fcmpset_acq_16(flagsp, &state,
789 if ((state & FOFFSET_LOCK_WAITING) == 0) {
790 if (!atomic_fcmpset_acq_16(flagsp, &state,
791 state | FOFFSET_LOCK_WAITING))
795 sleepq_add(&fp->f_vnread_flags, NULL, "vofflock", 0, 0);
796 sleepq_wait(&fp->f_vnread_flags, PUSER -1);
798 sleepq_lock(&fp->f_vnread_flags);
799 state = atomic_load_16(flagsp);
801 res = atomic_load_long(&fp->f_offset);
802 sleepq_release(&fp->f_vnread_flags);
807 foffset_unlock(struct file *fp, off_t val, int flags)
809 volatile short *flagsp;
812 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
814 if ((flags & FOF_NOUPDATE) == 0)
815 atomic_store_long(&fp->f_offset, val);
816 if ((flags & FOF_NEXTOFF_R) != 0)
817 fp->f_nextoff[UIO_READ] = val;
818 if ((flags & FOF_NEXTOFF_W) != 0)
819 fp->f_nextoff[UIO_WRITE] = val;
821 if ((flags & FOF_NOLOCK) != 0)
824 flagsp = &fp->f_vnread_flags;
825 state = atomic_load_16(flagsp);
826 if ((state & FOFFSET_LOCK_WAITING) == 0 &&
827 atomic_cmpset_rel_16(flagsp, state, 0))
830 sleepq_lock(&fp->f_vnread_flags);
831 MPASS((fp->f_vnread_flags & FOFFSET_LOCKED) != 0);
832 MPASS((fp->f_vnread_flags & FOFFSET_LOCK_WAITING) != 0);
833 fp->f_vnread_flags = 0;
834 sleepq_broadcast(&fp->f_vnread_flags, SLEEPQ_SLEEP, 0, 0);
835 sleepq_release(&fp->f_vnread_flags);
839 foffset_lock(struct file *fp, int flags)
844 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
846 mtxp = mtx_pool_find(mtxpool_sleep, fp);
848 if ((flags & FOF_NOLOCK) == 0) {
849 while (fp->f_vnread_flags & FOFFSET_LOCKED) {
850 fp->f_vnread_flags |= FOFFSET_LOCK_WAITING;
851 msleep(&fp->f_vnread_flags, mtxp, PUSER -1,
854 fp->f_vnread_flags |= FOFFSET_LOCKED;
862 foffset_unlock(struct file *fp, off_t val, int flags)
866 KASSERT((flags & FOF_OFFSET) == 0, ("FOF_OFFSET passed"));
868 mtxp = mtx_pool_find(mtxpool_sleep, fp);
870 if ((flags & FOF_NOUPDATE) == 0)
872 if ((flags & FOF_NEXTOFF_R) != 0)
873 fp->f_nextoff[UIO_READ] = val;
874 if ((flags & FOF_NEXTOFF_W) != 0)
875 fp->f_nextoff[UIO_WRITE] = val;
876 if ((flags & FOF_NOLOCK) == 0) {
877 KASSERT((fp->f_vnread_flags & FOFFSET_LOCKED) != 0,
878 ("Lost FOFFSET_LOCKED"));
879 if (fp->f_vnread_flags & FOFFSET_LOCK_WAITING)
880 wakeup(&fp->f_vnread_flags);
881 fp->f_vnread_flags = 0;
888 foffset_lock_uio(struct file *fp, struct uio *uio, int flags)
891 if ((flags & FOF_OFFSET) == 0)
892 uio->uio_offset = foffset_lock(fp, flags);
896 foffset_unlock_uio(struct file *fp, struct uio *uio, int flags)
899 if ((flags & FOF_OFFSET) == 0)
900 foffset_unlock(fp, uio->uio_offset, flags);
904 get_advice(struct file *fp, struct uio *uio)
909 ret = POSIX_FADV_NORMAL;
910 if (fp->f_advice == NULL || fp->f_vnode->v_type != VREG)
913 mtxp = mtx_pool_find(mtxpool_sleep, fp);
915 if (fp->f_advice != NULL &&
916 uio->uio_offset >= fp->f_advice->fa_start &&
917 uio->uio_offset + uio->uio_resid <= fp->f_advice->fa_end)
918 ret = fp->f_advice->fa_advice;
924 vn_read_from_obj(struct vnode *vp, struct uio *uio)
927 vm_page_t ma[io_hold_cnt + 2];
932 MPASS(uio->uio_resid <= ptoa(io_hold_cnt + 2));
933 obj = atomic_load_ptr(&vp->v_object);
935 return (EJUSTRETURN);
938 * Depends on type stability of vm_objects.
940 vm_object_pip_add(obj, 1);
941 if ((obj->flags & OBJ_DEAD) != 0) {
943 * Note that object might be already reused from the
944 * vnode, and the OBJ_DEAD flag cleared. This is fine,
945 * we recheck for DOOMED vnode state after all pages
946 * are busied, and retract then.
948 * But we check for OBJ_DEAD to ensure that we do not
949 * busy pages while vm_object_terminate_pages()
950 * processes the queue.
956 resid = uio->uio_resid;
957 off = uio->uio_offset;
958 for (i = 0; resid > 0; i++) {
959 MPASS(i < io_hold_cnt + 2);
960 ma[i] = vm_page_grab_unlocked(obj, atop(off),
961 VM_ALLOC_NOCREAT | VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY |
967 * Skip invalid pages. Valid mask can be partial only
968 * at EOF, and we clip later.
970 if (vm_page_none_valid(ma[i])) {
971 vm_page_sunbusy(ma[i]);
984 * Check VIRF_DOOMED after we busied our pages. Since
985 * vgonel() terminates the vnode' vm_object, it cannot
986 * process past pages busied by us.
988 if (VN_IS_DOOMED(vp)) {
993 resid = PAGE_SIZE - (uio->uio_offset & PAGE_MASK) + ptoa(i - 1);
994 if (resid > uio->uio_resid)
995 resid = uio->uio_resid;
998 * Unlocked read of vnp_size is safe because truncation cannot
999 * pass busied page. But we load vnp_size into a local
1000 * variable so that possible concurrent extension does not
1001 * break calculation.
1003 #if defined(__powerpc__) && !defined(__powerpc64__)
1004 vsz = obj->un_pager.vnp.vnp_size;
1006 vsz = atomic_load_64(&obj->un_pager.vnp.vnp_size);
1008 if (uio->uio_offset >= vsz) {
1009 error = EJUSTRETURN;
1012 if (uio->uio_offset + resid > vsz)
1013 resid = vsz - uio->uio_offset;
1015 error = vn_io_fault_pgmove(ma, uio->uio_offset & PAGE_MASK, resid, uio);
1018 for (j = 0; j < i; j++) {
1020 vm_page_reference(ma[j]);
1021 vm_page_sunbusy(ma[j]);
1024 vm_object_pip_wakeup(obj);
1027 return (uio->uio_resid == 0 ? 0 : EJUSTRETURN);
1031 * File table vnode read routine.
1034 vn_read(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
1042 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
1044 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
1047 if (fp->f_flag & FNONBLOCK)
1048 ioflag |= IO_NDELAY;
1049 if (fp->f_flag & O_DIRECT)
1050 ioflag |= IO_DIRECT;
1053 * Try to read from page cache. VIRF_DOOMED check is racy but
1054 * allows us to avoid unneeded work outright.
1056 if (vn_io_pgcache_read_enable && !mac_vnode_check_read_enabled() &&
1057 (vn_irflag_read(vp) & (VIRF_DOOMED | VIRF_PGREAD)) == VIRF_PGREAD) {
1058 error = VOP_READ_PGCACHE(vp, uio, ioflag, fp->f_cred);
1060 fp->f_nextoff[UIO_READ] = uio->uio_offset;
1063 if (error != EJUSTRETURN)
1067 advice = get_advice(fp, uio);
1068 vn_lock(vp, LK_SHARED | LK_RETRY);
1071 case POSIX_FADV_NORMAL:
1072 case POSIX_FADV_SEQUENTIAL:
1073 case POSIX_FADV_NOREUSE:
1074 ioflag |= sequential_heuristic(uio, fp);
1076 case POSIX_FADV_RANDOM:
1077 /* Disable read-ahead for random I/O. */
1080 orig_offset = uio->uio_offset;
1083 error = mac_vnode_check_read(active_cred, fp->f_cred, vp);
1086 error = VOP_READ(vp, uio, ioflag, fp->f_cred);
1087 fp->f_nextoff[UIO_READ] = uio->uio_offset;
1089 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
1090 orig_offset != uio->uio_offset)
1092 * Use POSIX_FADV_DONTNEED to flush pages and buffers
1093 * for the backing file after a POSIX_FADV_NOREUSE
1096 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
1097 POSIX_FADV_DONTNEED);
1102 * File table vnode write routine.
1105 vn_write(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags,
1113 bool need_finished_write;
1115 KASSERT(uio->uio_td == td, ("uio_td %p is not td %p",
1117 KASSERT(flags & FOF_OFFSET, ("No FOF_OFFSET"));
1119 if (vp->v_type == VREG)
1122 if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
1123 ioflag |= IO_APPEND;
1124 if (fp->f_flag & FNONBLOCK)
1125 ioflag |= IO_NDELAY;
1126 if (fp->f_flag & O_DIRECT)
1127 ioflag |= IO_DIRECT;
1129 mp = atomic_load_ptr(&vp->v_mount);
1130 if ((fp->f_flag & O_FSYNC) ||
1131 (mp != NULL && (mp->mnt_flag & MNT_SYNCHRONOUS)))
1135 * For O_DSYNC we set both IO_SYNC and IO_DATASYNC, so that VOP_WRITE()
1136 * implementations that don't understand IO_DATASYNC fall back to full
1139 if (fp->f_flag & O_DSYNC)
1140 ioflag |= IO_SYNC | IO_DATASYNC;
1142 need_finished_write = false;
1143 if (vp->v_type != VCHR) {
1144 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
1147 need_finished_write = true;
1150 advice = get_advice(fp, uio);
1152 vn_lock(vp, vn_lktype_write(mp, vp) | LK_RETRY);
1154 case POSIX_FADV_NORMAL:
1155 case POSIX_FADV_SEQUENTIAL:
1156 case POSIX_FADV_NOREUSE:
1157 ioflag |= sequential_heuristic(uio, fp);
1159 case POSIX_FADV_RANDOM:
1160 /* XXX: Is this correct? */
1163 orig_offset = uio->uio_offset;
1166 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
1169 error = VOP_WRITE(vp, uio, ioflag, fp->f_cred);
1170 fp->f_nextoff[UIO_WRITE] = uio->uio_offset;
1172 if (need_finished_write)
1173 vn_finished_write(mp);
1174 if (error == 0 && advice == POSIX_FADV_NOREUSE &&
1175 orig_offset != uio->uio_offset)
1177 * Use POSIX_FADV_DONTNEED to flush pages and buffers
1178 * for the backing file after a POSIX_FADV_NOREUSE
1181 error = VOP_ADVISE(vp, orig_offset, uio->uio_offset - 1,
1182 POSIX_FADV_DONTNEED);
1188 * The vn_io_fault() is a wrapper around vn_read() and vn_write() to
1189 * prevent the following deadlock:
1191 * Assume that the thread A reads from the vnode vp1 into userspace
1192 * buffer buf1 backed by the pages of vnode vp2. If a page in buf1 is
1193 * currently not resident, then system ends up with the call chain
1194 * vn_read() -> VOP_READ(vp1) -> uiomove() -> [Page Fault] ->
1195 * vm_fault(buf1) -> vnode_pager_getpages(vp2) -> VOP_GETPAGES(vp2)
1196 * which establishes lock order vp1->vn_lock, then vp2->vn_lock.
1197 * If, at the same time, thread B reads from vnode vp2 into buffer buf2
1198 * backed by the pages of vnode vp1, and some page in buf2 is not
1199 * resident, we get a reversed order vp2->vn_lock, then vp1->vn_lock.
1201 * To prevent the lock order reversal and deadlock, vn_io_fault() does
1202 * not allow page faults to happen during VOP_READ() or VOP_WRITE().
1203 * Instead, it first tries to do the whole range i/o with pagefaults
1204 * disabled. If all pages in the i/o buffer are resident and mapped,
1205 * VOP will succeed (ignoring the genuine filesystem errors).
1206 * Otherwise, we get back EFAULT, and vn_io_fault() falls back to do
1207 * i/o in chunks, with all pages in the chunk prefaulted and held
1208 * using vm_fault_quick_hold_pages().
1210 * Filesystems using this deadlock avoidance scheme should use the
1211 * array of the held pages from uio, saved in the curthread->td_ma,
1212 * instead of doing uiomove(). A helper function
1213 * vn_io_fault_uiomove() converts uiomove request into
1214 * uiomove_fromphys() over td_ma array.
1216 * Since vnode locks do not cover the whole i/o anymore, rangelocks
1217 * make the current i/o request atomic with respect to other i/os and
1222 * Decode vn_io_fault_args and perform the corresponding i/o.
1225 vn_io_fault_doio(struct vn_io_fault_args *args, struct uio *uio,
1231 save = vm_fault_disable_pagefaults();
1232 switch (args->kind) {
1233 case VN_IO_FAULT_FOP:
1234 error = (args->args.fop_args.doio)(args->args.fop_args.fp,
1235 uio, args->cred, args->flags, td);
1237 case VN_IO_FAULT_VOP:
1238 if (uio->uio_rw == UIO_READ) {
1239 error = VOP_READ(args->args.vop_args.vp, uio,
1240 args->flags, args->cred);
1241 } else if (uio->uio_rw == UIO_WRITE) {
1242 error = VOP_WRITE(args->args.vop_args.vp, uio,
1243 args->flags, args->cred);
1247 panic("vn_io_fault_doio: unknown kind of io %d %d",
1248 args->kind, uio->uio_rw);
1250 vm_fault_enable_pagefaults(save);
1255 vn_io_fault_touch(char *base, const struct uio *uio)
1260 if (r == -1 || (uio->uio_rw == UIO_READ && subyte(base, r) == -1))
1266 vn_io_fault_prefault_user(const struct uio *uio)
1269 const struct iovec *iov;
1274 KASSERT(uio->uio_segflg == UIO_USERSPACE,
1275 ("vn_io_fault_prefault userspace"));
1279 resid = uio->uio_resid;
1280 base = iov->iov_base;
1283 error = vn_io_fault_touch(base, uio);
1286 if (len < PAGE_SIZE) {
1288 error = vn_io_fault_touch(base + len - 1, uio);
1293 if (++i >= uio->uio_iovcnt)
1295 iov = uio->uio_iov + i;
1296 base = iov->iov_base;
1308 * Common code for vn_io_fault(), agnostic to the kind of i/o request.
1309 * Uses vn_io_fault_doio() to make the call to an actual i/o function.
1310 * Used from vn_rdwr() and vn_io_fault(), which encode the i/o request
1311 * into args and call vn_io_fault1() to handle faults during the user
1312 * mode buffer accesses.
1315 vn_io_fault1(struct vnode *vp, struct uio *uio, struct vn_io_fault_args *args,
1318 vm_page_t ma[io_hold_cnt + 2];
1319 struct uio *uio_clone, short_uio;
1320 struct iovec short_iovec[1];
1321 vm_page_t *prev_td_ma;
1323 vm_offset_t addr, end;
1326 int error, cnt, saveheld, prev_td_ma_cnt;
1328 if (vn_io_fault_prefault) {
1329 error = vn_io_fault_prefault_user(uio);
1331 return (error); /* Or ignore ? */
1334 prot = uio->uio_rw == UIO_READ ? VM_PROT_WRITE : VM_PROT_READ;
1337 * The UFS follows IO_UNIT directive and replays back both
1338 * uio_offset and uio_resid if an error is encountered during the
1339 * operation. But, since the iovec may be already advanced,
1340 * uio is still in an inconsistent state.
1342 * Cache a copy of the original uio, which is advanced to the redo
1343 * point using UIO_NOCOPY below.
1345 uio_clone = cloneuio(uio);
1346 resid = uio->uio_resid;
1348 short_uio.uio_segflg = UIO_USERSPACE;
1349 short_uio.uio_rw = uio->uio_rw;
1350 short_uio.uio_td = uio->uio_td;
1352 error = vn_io_fault_doio(args, uio, td);
1353 if (error != EFAULT)
1356 atomic_add_long(&vn_io_faults_cnt, 1);
1357 uio_clone->uio_segflg = UIO_NOCOPY;
1358 uiomove(NULL, resid - uio->uio_resid, uio_clone);
1359 uio_clone->uio_segflg = uio->uio_segflg;
1361 saveheld = curthread_pflags_set(TDP_UIOHELD);
1362 prev_td_ma = td->td_ma;
1363 prev_td_ma_cnt = td->td_ma_cnt;
1365 while (uio_clone->uio_resid != 0) {
1366 len = uio_clone->uio_iov->iov_len;
1368 KASSERT(uio_clone->uio_iovcnt >= 1,
1369 ("iovcnt underflow"));
1370 uio_clone->uio_iov++;
1371 uio_clone->uio_iovcnt--;
1374 if (len > ptoa(io_hold_cnt))
1375 len = ptoa(io_hold_cnt);
1376 addr = (uintptr_t)uio_clone->uio_iov->iov_base;
1377 end = round_page(addr + len);
1382 cnt = atop(end - trunc_page(addr));
1384 * A perfectly misaligned address and length could cause
1385 * both the start and the end of the chunk to use partial
1386 * page. +2 accounts for such a situation.
1388 cnt = vm_fault_quick_hold_pages(&td->td_proc->p_vmspace->vm_map,
1389 addr, len, prot, ma, io_hold_cnt + 2);
1394 short_uio.uio_iov = &short_iovec[0];
1395 short_iovec[0].iov_base = (void *)addr;
1396 short_uio.uio_iovcnt = 1;
1397 short_uio.uio_resid = short_iovec[0].iov_len = len;
1398 short_uio.uio_offset = uio_clone->uio_offset;
1400 td->td_ma_cnt = cnt;
1402 error = vn_io_fault_doio(args, &short_uio, td);
1403 vm_page_unhold_pages(ma, cnt);
1404 adv = len - short_uio.uio_resid;
1406 uio_clone->uio_iov->iov_base =
1407 (char *)uio_clone->uio_iov->iov_base + adv;
1408 uio_clone->uio_iov->iov_len -= adv;
1409 uio_clone->uio_resid -= adv;
1410 uio_clone->uio_offset += adv;
1412 uio->uio_resid -= adv;
1413 uio->uio_offset += adv;
1415 if (error != 0 || adv == 0)
1418 td->td_ma = prev_td_ma;
1419 td->td_ma_cnt = prev_td_ma_cnt;
1420 curthread_pflags_restore(saveheld);
1422 free(uio_clone, M_IOV);
1427 vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred,
1428 int flags, struct thread *td)
1433 struct vn_io_fault_args args;
1436 doio = uio->uio_rw == UIO_READ ? vn_read : vn_write;
1440 * The ability to read(2) on a directory has historically been
1441 * allowed for all users, but this can and has been the source of
1442 * at least one security issue in the past. As such, it is now hidden
1443 * away behind a sysctl for those that actually need it to use it, and
1444 * restricted to root when it's turned on to make it relatively safe to
1445 * leave on for longer sessions of need.
1447 if (vp->v_type == VDIR) {
1448 KASSERT(uio->uio_rw == UIO_READ,
1449 ("illegal write attempted on a directory"));
1450 if (!vfs_allow_read_dir)
1452 if ((error = priv_check(td, PRIV_VFS_READ_DIR)) != 0)
1456 foffset_lock_uio(fp, uio, flags);
1457 if (do_vn_io_fault(vp, uio)) {
1458 args.kind = VN_IO_FAULT_FOP;
1459 args.args.fop_args.fp = fp;
1460 args.args.fop_args.doio = doio;
1461 args.cred = active_cred;
1462 args.flags = flags | FOF_OFFSET;
1463 if (uio->uio_rw == UIO_READ) {
1464 rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset,
1465 uio->uio_offset + uio->uio_resid);
1466 } else if ((fp->f_flag & O_APPEND) != 0 ||
1467 (flags & FOF_OFFSET) == 0) {
1468 /* For appenders, punt and lock the whole range. */
1469 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1471 rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset,
1472 uio->uio_offset + uio->uio_resid);
1474 error = vn_io_fault1(vp, uio, &args, td);
1475 vn_rangelock_unlock(vp, rl_cookie);
1477 error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td);
1479 foffset_unlock_uio(fp, uio, flags);
1484 * Helper function to perform the requested uiomove operation using
1485 * the held pages for io->uio_iov[0].iov_base buffer instead of
1486 * copyin/copyout. Access to the pages with uiomove_fromphys()
1487 * instead of iov_base prevents page faults that could occur due to
1488 * pmap_collect() invalidating the mapping created by
1489 * vm_fault_quick_hold_pages(), or pageout daemon, page laundry or
1490 * object cleanup revoking the write access from page mappings.
1492 * Filesystems specified MNTK_NO_IOPF shall use vn_io_fault_uiomove()
1493 * instead of plain uiomove().
1496 vn_io_fault_uiomove(char *data, int xfersize, struct uio *uio)
1498 struct uio transp_uio;
1499 struct iovec transp_iov[1];
1505 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1506 uio->uio_segflg != UIO_USERSPACE)
1507 return (uiomove(data, xfersize, uio));
1509 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1510 transp_iov[0].iov_base = data;
1511 transp_uio.uio_iov = &transp_iov[0];
1512 transp_uio.uio_iovcnt = 1;
1513 if (xfersize > uio->uio_resid)
1514 xfersize = uio->uio_resid;
1515 transp_uio.uio_resid = transp_iov[0].iov_len = xfersize;
1516 transp_uio.uio_offset = 0;
1517 transp_uio.uio_segflg = UIO_SYSSPACE;
1519 * Since transp_iov points to data, and td_ma page array
1520 * corresponds to original uio->uio_iov, we need to invert the
1521 * direction of the i/o operation as passed to
1522 * uiomove_fromphys().
1524 switch (uio->uio_rw) {
1526 transp_uio.uio_rw = UIO_READ;
1529 transp_uio.uio_rw = UIO_WRITE;
1532 transp_uio.uio_td = uio->uio_td;
1533 error = uiomove_fromphys(td->td_ma,
1534 ((vm_offset_t)uio->uio_iov->iov_base) & PAGE_MASK,
1535 xfersize, &transp_uio);
1536 adv = xfersize - transp_uio.uio_resid;
1538 (((vm_offset_t)uio->uio_iov->iov_base + adv) >> PAGE_SHIFT) -
1539 (((vm_offset_t)uio->uio_iov->iov_base) >> PAGE_SHIFT);
1541 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1543 td->td_ma_cnt -= pgadv;
1544 uio->uio_iov->iov_base = (char *)uio->uio_iov->iov_base + adv;
1545 uio->uio_iov->iov_len -= adv;
1546 uio->uio_resid -= adv;
1547 uio->uio_offset += adv;
1552 vn_io_fault_pgmove(vm_page_t ma[], vm_offset_t offset, int xfersize,
1556 vm_offset_t iov_base;
1560 if ((td->td_pflags & TDP_UIOHELD) == 0 ||
1561 uio->uio_segflg != UIO_USERSPACE)
1562 return (uiomove_fromphys(ma, offset, xfersize, uio));
1564 KASSERT(uio->uio_iovcnt == 1, ("uio_iovcnt %d", uio->uio_iovcnt));
1565 cnt = xfersize > uio->uio_resid ? uio->uio_resid : xfersize;
1566 iov_base = (vm_offset_t)uio->uio_iov->iov_base;
1567 switch (uio->uio_rw) {
1569 pmap_copy_pages(td->td_ma, iov_base & PAGE_MASK, ma,
1573 pmap_copy_pages(ma, offset, td->td_ma, iov_base & PAGE_MASK,
1577 pgadv = ((iov_base + cnt) >> PAGE_SHIFT) - (iov_base >> PAGE_SHIFT);
1579 KASSERT(td->td_ma_cnt >= pgadv, ("consumed pages %d %d", td->td_ma_cnt,
1581 td->td_ma_cnt -= pgadv;
1582 uio->uio_iov->iov_base = (char *)(iov_base + cnt);
1583 uio->uio_iov->iov_len -= cnt;
1584 uio->uio_resid -= cnt;
1585 uio->uio_offset += cnt;
1590 * File table truncate routine.
1593 vn_truncate(struct file *fp, off_t length, struct ucred *active_cred,
1605 * Lock the whole range for truncation. Otherwise split i/o
1606 * might happen partly before and partly after the truncation.
1608 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
1609 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
1612 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1613 AUDIT_ARG_VNODE1(vp);
1614 if (vp->v_type == VDIR) {
1619 error = mac_vnode_check_write(active_cred, fp->f_cred, vp);
1623 error = vn_truncate_locked(vp, length, (fp->f_flag & O_FSYNC) != 0,
1627 vn_finished_write(mp);
1629 vn_rangelock_unlock(vp, rl_cookie);
1630 if (error == ERELOOKUP)
1636 * Truncate a file that is already locked.
1639 vn_truncate_locked(struct vnode *vp, off_t length, bool sync,
1645 error = VOP_ADD_WRITECOUNT(vp, 1);
1648 vattr.va_size = length;
1650 vattr.va_vaflags |= VA_SYNC;
1651 error = VOP_SETATTR(vp, &vattr, cred);
1652 VOP_ADD_WRITECOUNT_CHECKED(vp, -1);
1658 * File table vnode stat routine.
1661 vn_statfile(struct file *fp, struct stat *sb, struct ucred *active_cred,
1664 struct vnode *vp = fp->f_vnode;
1667 vn_lock(vp, LK_SHARED | LK_RETRY);
1668 error = VOP_STAT(vp, sb, active_cred, fp->f_cred, td);
1675 * File table vnode ioctl routine.
1678 vn_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred,
1683 struct fiobmap2_arg *bmarg;
1687 switch (vp->v_type) {
1692 vn_lock(vp, LK_SHARED | LK_RETRY);
1693 error = VOP_GETATTR(vp, &vattr, active_cred);
1696 *(int *)data = vattr.va_size - fp->f_offset;
1699 bmarg = (struct fiobmap2_arg *)data;
1700 vn_lock(vp, LK_SHARED | LK_RETRY);
1702 error = mac_vnode_check_read(active_cred, fp->f_cred,
1706 error = VOP_BMAP(vp, bmarg->bn, NULL,
1707 &bmarg->bn, &bmarg->runp, &bmarg->runb);
1714 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1719 return (VOP_IOCTL(vp, com, data, fp->f_flag,
1727 * File table vnode poll routine.
1730 vn_poll(struct file *fp, int events, struct ucred *active_cred,
1737 #if defined(MAC) || defined(AUDIT)
1738 if (AUDITING_TD(td) || mac_vnode_check_poll_enabled()) {
1739 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1740 AUDIT_ARG_VNODE1(vp);
1741 error = mac_vnode_check_poll(active_cred, fp->f_cred, vp);
1747 error = VOP_POLL(vp, events, fp->f_cred, td);
1752 * Acquire the requested lock and then check for validity. LK_RETRY
1753 * permits vn_lock to return doomed vnodes.
1755 static int __noinline
1756 _vn_lock_fallback(struct vnode *vp, int flags, const char *file, int line,
1760 KASSERT((flags & LK_RETRY) == 0 || error == 0,
1761 ("vn_lock: error %d incompatible with flags %#x", error, flags));
1764 VNASSERT(VN_IS_DOOMED(vp), vp, ("vnode not doomed"));
1766 if ((flags & LK_RETRY) == 0) {
1777 * Nothing to do if we got the lock.
1783 * Interlock was dropped by the call in _vn_lock.
1785 flags &= ~LK_INTERLOCK;
1787 error = VOP_LOCK1(vp, flags, file, line);
1788 } while (error != 0);
1793 _vn_lock(struct vnode *vp, int flags, const char *file, int line)
1797 VNASSERT((flags & LK_TYPE_MASK) != 0, vp,
1798 ("vn_lock: no locktype (%d passed)", flags));
1799 VNPASS(vp->v_holdcnt > 0, vp);
1800 error = VOP_LOCK1(vp, flags, file, line);
1801 if (__predict_false(error != 0 || VN_IS_DOOMED(vp)))
1802 return (_vn_lock_fallback(vp, flags, file, line, error));
1807 * File table vnode close routine.
1810 vn_closefile(struct file *fp, struct thread *td)
1818 fp->f_ops = &badfileops;
1819 ref = (fp->f_flag & FHASLOCK) != 0 && fp->f_type == DTYPE_VNODE;
1821 error = vn_close1(vp, fp->f_flag, fp->f_cred, td, ref);
1823 if (__predict_false(ref)) {
1824 lf.l_whence = SEEK_SET;
1827 lf.l_type = F_UNLCK;
1828 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK);
1835 * Preparing to start a filesystem write operation. If the operation is
1836 * permitted, then we bump the count of operations in progress and
1837 * proceed. If a suspend request is in progress, we wait until the
1838 * suspension is over, and then proceed.
1841 vn_start_write_refed(struct mount *mp, int flags, bool mplocked)
1843 struct mount_pcpu *mpcpu;
1846 if (__predict_true(!mplocked) && (flags & V_XSLEEP) == 0 &&
1847 vfs_op_thread_enter(mp, mpcpu)) {
1848 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0);
1849 vfs_mp_count_add_pcpu(mpcpu, writeopcount, 1);
1850 vfs_op_thread_exit(mp, mpcpu);
1855 mtx_assert(MNT_MTX(mp), MA_OWNED);
1862 * Check on status of suspension.
1864 if ((curthread->td_pflags & TDP_IGNSUSP) == 0 ||
1865 mp->mnt_susp_owner != curthread) {
1866 mflags = ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ?
1867 (flags & PCATCH) : 0) | (PUSER - 1);
1868 while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
1869 if (flags & V_NOWAIT) {
1870 error = EWOULDBLOCK;
1873 error = msleep(&mp->mnt_flag, MNT_MTX(mp), mflags,
1879 if (flags & V_XSLEEP)
1881 mp->mnt_writeopcount++;
1883 if (error != 0 || (flags & V_XSLEEP) != 0)
1890 vn_start_write(struct vnode *vp, struct mount **mpp, int flags)
1895 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1896 ("V_MNTREF requires mp"));
1900 * If a vnode is provided, get and return the mount point that
1901 * to which it will write.
1904 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1906 if (error != EOPNOTSUPP)
1911 if ((mp = *mpp) == NULL)
1915 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1917 * As long as a vnode is not provided we need to acquire a
1918 * refcount for the provided mountpoint too, in order to
1919 * emulate a vfs_ref().
1921 if (vp == NULL && (flags & V_MNTREF) == 0)
1924 return (vn_start_write_refed(mp, flags, false));
1928 * Secondary suspension. Used by operations such as vop_inactive
1929 * routines that are needed by the higher level functions. These
1930 * are allowed to proceed until all the higher level functions have
1931 * completed (indicated by mnt_writeopcount dropping to zero). At that
1932 * time, these operations are halted until the suspension is over.
1935 vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags)
1940 KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL),
1941 ("V_MNTREF requires mp"));
1945 if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) {
1947 if (error != EOPNOTSUPP)
1953 * If we are not suspended or have not yet reached suspended
1954 * mode, then let the operation proceed.
1956 if ((mp = *mpp) == NULL)
1960 * VOP_GETWRITEMOUNT() returns with the mp refcount held through
1962 * As long as a vnode is not provided we need to acquire a
1963 * refcount for the provided mountpoint too, in order to
1964 * emulate a vfs_ref().
1967 if (vp == NULL && (flags & V_MNTREF) == 0)
1969 if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) {
1970 mp->mnt_secondary_writes++;
1971 mp->mnt_secondary_accwrites++;
1975 if (flags & V_NOWAIT) {
1978 return (EWOULDBLOCK);
1981 * Wait for the suspension to finish.
1983 error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | PDROP |
1984 ((mp->mnt_vfc->vfc_flags & VFCF_SBDRY) != 0 ? (flags & PCATCH) : 0),
1993 * Filesystem write operation has completed. If we are suspending and this
1994 * operation is the last one, notify the suspender that the suspension is
1998 vn_finished_write(struct mount *mp)
2000 struct mount_pcpu *mpcpu;
2006 if (vfs_op_thread_enter(mp, mpcpu)) {
2007 vfs_mp_count_sub_pcpu(mpcpu, writeopcount, 1);
2008 vfs_mp_count_sub_pcpu(mpcpu, ref, 1);
2009 vfs_op_thread_exit(mp, mpcpu);
2014 vfs_assert_mount_counters(mp);
2016 c = --mp->mnt_writeopcount;
2017 if (mp->mnt_vfs_ops == 0) {
2018 MPASS((mp->mnt_kern_flag & MNTK_SUSPEND) == 0);
2023 vfs_dump_mount_counters(mp);
2024 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && c == 0)
2025 wakeup(&mp->mnt_writeopcount);
2030 * Filesystem secondary write operation has completed. If we are
2031 * suspending and this operation is the last one, notify the suspender
2032 * that the suspension is now in effect.
2035 vn_finished_secondary_write(struct mount *mp)
2041 mp->mnt_secondary_writes--;
2042 if (mp->mnt_secondary_writes < 0)
2043 panic("vn_finished_secondary_write: neg cnt");
2044 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 &&
2045 mp->mnt_secondary_writes <= 0)
2046 wakeup(&mp->mnt_secondary_writes);
2051 * Request a filesystem to suspend write operations.
2054 vfs_write_suspend(struct mount *mp, int flags)
2061 vfs_assert_mount_counters(mp);
2062 if (mp->mnt_susp_owner == curthread) {
2063 vfs_op_exit_locked(mp);
2067 while (mp->mnt_kern_flag & MNTK_SUSPEND)
2068 msleep(&mp->mnt_flag, MNT_MTX(mp), PUSER - 1, "wsuspfs", 0);
2071 * Unmount holds a write reference on the mount point. If we
2072 * own busy reference and drain for writers, we deadlock with
2073 * the reference draining in the unmount path. Callers of
2074 * vfs_write_suspend() must specify VS_SKIP_UNMOUNT if
2075 * vfs_busy() reference is owned and caller is not in the
2078 if ((flags & VS_SKIP_UNMOUNT) != 0 &&
2079 (mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) {
2080 vfs_op_exit_locked(mp);
2085 mp->mnt_kern_flag |= MNTK_SUSPEND;
2086 mp->mnt_susp_owner = curthread;
2087 if (mp->mnt_writeopcount > 0)
2088 (void) msleep(&mp->mnt_writeopcount,
2089 MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0);
2092 if ((error = VFS_SYNC(mp, MNT_SUSPEND)) != 0) {
2093 vfs_write_resume(mp, 0);
2094 /* vfs_write_resume does vfs_op_exit() for us */
2100 * Request a filesystem to resume write operations.
2103 vfs_write_resume(struct mount *mp, int flags)
2107 if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) {
2108 KASSERT(mp->mnt_susp_owner == curthread, ("mnt_susp_owner"));
2109 mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPEND2 |
2111 mp->mnt_susp_owner = NULL;
2112 wakeup(&mp->mnt_writeopcount);
2113 wakeup(&mp->mnt_flag);
2114 curthread->td_pflags &= ~TDP_IGNSUSP;
2115 if ((flags & VR_START_WRITE) != 0) {
2117 mp->mnt_writeopcount++;
2120 if ((flags & VR_NO_SUSPCLR) == 0)
2123 } else if ((flags & VR_START_WRITE) != 0) {
2125 vn_start_write_refed(mp, 0, true);
2132 * Helper loop around vfs_write_suspend() for filesystem unmount VFS
2136 vfs_write_suspend_umnt(struct mount *mp)
2140 KASSERT((curthread->td_pflags & TDP_IGNSUSP) == 0,
2141 ("vfs_write_suspend_umnt: recursed"));
2143 /* dounmount() already called vn_start_write(). */
2145 vn_finished_write(mp);
2146 error = vfs_write_suspend(mp, 0);
2148 vn_start_write(NULL, &mp, V_WAIT);
2152 if ((mp->mnt_kern_flag & MNTK_SUSPENDED) != 0)
2155 vn_start_write(NULL, &mp, V_WAIT);
2157 mp->mnt_kern_flag &= ~(MNTK_SUSPENDED | MNTK_SUSPEND2);
2158 wakeup(&mp->mnt_flag);
2160 curthread->td_pflags |= TDP_IGNSUSP;
2165 * Implement kqueues for files by translating it to vnode operation.
2168 vn_kqfilter(struct file *fp, struct knote *kn)
2171 return (VOP_KQFILTER(fp->f_vnode, kn));
2175 vn_kqfilter_opath(struct file *fp, struct knote *kn)
2177 if ((fp->f_flag & FKQALLOWED) == 0)
2179 return (vn_kqfilter(fp, kn));
2183 * Simplified in-kernel wrapper calls for extended attribute access.
2184 * Both calls pass in a NULL credential, authorizing as "kernel" access.
2185 * Set IO_NODELOCKED in ioflg if the vnode is already locked.
2188 vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace,
2189 const char *attrname, int *buflen, char *buf, struct thread *td)
2195 iov.iov_len = *buflen;
2198 auio.uio_iov = &iov;
2199 auio.uio_iovcnt = 1;
2200 auio.uio_rw = UIO_READ;
2201 auio.uio_segflg = UIO_SYSSPACE;
2203 auio.uio_offset = 0;
2204 auio.uio_resid = *buflen;
2206 if ((ioflg & IO_NODELOCKED) == 0)
2207 vn_lock(vp, LK_SHARED | LK_RETRY);
2209 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2211 /* authorize attribute retrieval as kernel */
2212 error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL,
2215 if ((ioflg & IO_NODELOCKED) == 0)
2219 *buflen = *buflen - auio.uio_resid;
2226 * XXX failure mode if partially written?
2229 vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace,
2230 const char *attrname, int buflen, char *buf, struct thread *td)
2237 iov.iov_len = buflen;
2240 auio.uio_iov = &iov;
2241 auio.uio_iovcnt = 1;
2242 auio.uio_rw = UIO_WRITE;
2243 auio.uio_segflg = UIO_SYSSPACE;
2245 auio.uio_offset = 0;
2246 auio.uio_resid = buflen;
2248 if ((ioflg & IO_NODELOCKED) == 0) {
2249 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2251 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2254 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2256 /* authorize attribute setting as kernel */
2257 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td);
2259 if ((ioflg & IO_NODELOCKED) == 0) {
2260 vn_finished_write(mp);
2268 vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace,
2269 const char *attrname, struct thread *td)
2274 if ((ioflg & IO_NODELOCKED) == 0) {
2275 if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0)
2277 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2280 ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held");
2282 /* authorize attribute removal as kernel */
2283 error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td);
2284 if (error == EOPNOTSUPP)
2285 error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL,
2288 if ((ioflg & IO_NODELOCKED) == 0) {
2289 vn_finished_write(mp);
2297 vn_get_ino_alloc_vget(struct mount *mp, void *arg, int lkflags,
2301 return (VFS_VGET(mp, *(ino_t *)arg, lkflags, rvp));
2305 vn_vget_ino(struct vnode *vp, ino_t ino, int lkflags, struct vnode **rvp)
2308 return (vn_vget_ino_gen(vp, vn_get_ino_alloc_vget, &ino,
2313 vn_vget_ino_gen(struct vnode *vp, vn_get_ino_t alloc, void *alloc_arg,
2314 int lkflags, struct vnode **rvp)
2319 ASSERT_VOP_LOCKED(vp, "vn_vget_ino_get");
2321 ltype = VOP_ISLOCKED(vp);
2322 KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED,
2323 ("vn_vget_ino: vp not locked"));
2324 error = vfs_busy(mp, MBF_NOWAIT);
2328 error = vfs_busy(mp, 0);
2329 vn_lock(vp, ltype | LK_RETRY);
2333 if (VN_IS_DOOMED(vp)) {
2339 error = alloc(mp, alloc_arg, lkflags, rvp);
2341 if (error != 0 || *rvp != vp)
2342 vn_lock(vp, ltype | LK_RETRY);
2343 if (VN_IS_DOOMED(vp)) {
2356 vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio,
2366 * There are conditions where the limit is to be ignored.
2367 * However, since it is almost never reached, check it first.
2369 ktr_write = (td->td_pflags & TDP_INKTRACE) != 0;
2370 lim = lim_cur(td, RLIMIT_FSIZE);
2371 if (__predict_false(ktr_write))
2372 lim = td->td_ktr_io_lim;
2373 if (__predict_true((uoff_t)uio->uio_offset + uio->uio_resid <= lim))
2377 * The limit is reached.
2379 if (vp->v_type != VREG ||
2380 (td->td_pflags2 & TDP2_ACCT) != 0)
2383 if (!ktr_write || ktr_filesize_limit_signal) {
2384 PROC_LOCK(td->td_proc);
2385 kern_psignal(td->td_proc, SIGXFSZ);
2386 PROC_UNLOCK(td->td_proc);
2392 vn_chmod(struct file *fp, mode_t mode, struct ucred *active_cred,
2399 vn_lock(vp, LK_SHARED | LK_RETRY);
2400 AUDIT_ARG_VNODE1(vp);
2403 return (setfmode(td, active_cred, vp, mode));
2407 vn_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred,
2414 vn_lock(vp, LK_SHARED | LK_RETRY);
2415 AUDIT_ARG_VNODE1(vp);
2418 return (setfown(td, active_cred, vp, uid, gid));
2422 vn_pages_remove(struct vnode *vp, vm_pindex_t start, vm_pindex_t end)
2426 if ((object = vp->v_object) == NULL)
2428 VM_OBJECT_WLOCK(object);
2429 vm_object_page_remove(object, start, end, 0);
2430 VM_OBJECT_WUNLOCK(object);
2434 vn_bmap_seekhole_locked(struct vnode *vp, u_long cmd, off_t *off,
2443 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
2444 ("%s: Wrong command %lu", __func__, cmd));
2445 ASSERT_VOP_LOCKED(vp, "vn_bmap_seekhole_locked");
2447 if (vp->v_type != VREG) {
2451 error = VOP_GETATTR(vp, &va, cred);
2455 if (noff >= va.va_size) {
2459 bsize = vp->v_mount->mnt_stat.f_iosize;
2460 for (bn = noff / bsize; noff < va.va_size; bn++, noff += bsize -
2462 error = VOP_BMAP(vp, bn, NULL, &bnp, NULL, NULL);
2463 if (error == EOPNOTSUPP) {
2467 if ((bnp == -1 && cmd == FIOSEEKHOLE) ||
2468 (bnp != -1 && cmd == FIOSEEKDATA)) {
2475 if (noff > va.va_size)
2477 /* noff == va.va_size. There is an implicit hole at the end of file. */
2478 if (cmd == FIOSEEKDATA)
2487 vn_bmap_seekhole(struct vnode *vp, u_long cmd, off_t *off, struct ucred *cred)
2491 KASSERT(cmd == FIOSEEKHOLE || cmd == FIOSEEKDATA,
2492 ("%s: Wrong command %lu", __func__, cmd));
2494 if (vn_lock(vp, LK_SHARED) != 0)
2496 error = vn_bmap_seekhole_locked(vp, cmd, off, cred);
2502 vn_seek(struct file *fp, off_t offset, int whence, struct thread *td)
2507 off_t foffset, size;
2510 cred = td->td_ucred;
2512 foffset = foffset_lock(fp, 0);
2513 noneg = (vp->v_type != VCHR);
2519 (offset > 0 && foffset > OFF_MAX - offset))) {
2526 vn_lock(vp, LK_SHARED | LK_RETRY);
2527 error = VOP_GETATTR(vp, &vattr, cred);
2533 * If the file references a disk device, then fetch
2534 * the media size and use that to determine the ending
2537 if (vattr.va_size == 0 && vp->v_type == VCHR &&
2538 fo_ioctl(fp, DIOCGMEDIASIZE, &size, cred, td) == 0)
2539 vattr.va_size = size;
2541 (vattr.va_size > OFF_MAX ||
2542 (offset > 0 && vattr.va_size > OFF_MAX - offset))) {
2546 offset += vattr.va_size;
2551 error = fo_ioctl(fp, FIOSEEKDATA, &offset, cred, td);
2552 if (error == ENOTTY)
2556 error = fo_ioctl(fp, FIOSEEKHOLE, &offset, cred, td);
2557 if (error == ENOTTY)
2563 if (error == 0 && noneg && offset < 0)
2567 VFS_KNOTE_UNLOCKED(vp, 0);
2568 td->td_uretoff.tdu_off = offset;
2570 foffset_unlock(fp, offset, error != 0 ? FOF_NOUPDATE : 0);
2575 vn_utimes_perm(struct vnode *vp, struct vattr *vap, struct ucred *cred,
2581 * Grant permission if the caller is the owner of the file, or
2582 * the super-user, or has ACL_WRITE_ATTRIBUTES permission on
2583 * on the file. If the time pointer is null, then write
2584 * permission on the file is also sufficient.
2586 * From NFSv4.1, draft 21, 6.2.1.3.1, Discussion of Mask Attributes:
2587 * A user having ACL_WRITE_DATA or ACL_WRITE_ATTRIBUTES
2588 * will be allowed to set the times [..] to the current
2591 error = VOP_ACCESSX(vp, VWRITE_ATTRIBUTES, cred, td);
2592 if (error != 0 && (vap->va_vaflags & VA_UTIMES_NULL) != 0)
2593 error = VOP_ACCESS(vp, VWRITE, cred, td);
2598 vn_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp)
2603 if (fp->f_type == DTYPE_FIFO)
2604 kif->kf_type = KF_TYPE_FIFO;
2606 kif->kf_type = KF_TYPE_VNODE;
2609 FILEDESC_SUNLOCK(fdp);
2610 error = vn_fill_kinfo_vnode(vp, kif);
2612 FILEDESC_SLOCK(fdp);
2617 vn_fill_junk(struct kinfo_file *kif)
2622 * Simulate vn_fullpath returning changing values for a given
2623 * vp during e.g. coredump.
2625 len = (arc4random() % (sizeof(kif->kf_path) - 2)) + 1;
2626 olen = strlen(kif->kf_path);
2628 strcpy(&kif->kf_path[len - 1], "$");
2630 for (; olen < len; olen++)
2631 strcpy(&kif->kf_path[olen], "A");
2635 vn_fill_kinfo_vnode(struct vnode *vp, struct kinfo_file *kif)
2638 char *fullpath, *freepath;
2641 kif->kf_un.kf_file.kf_file_type = vntype_to_kinfo(vp->v_type);
2644 error = vn_fullpath(vp, &fullpath, &freepath);
2646 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
2648 if (freepath != NULL)
2649 free(freepath, M_TEMP);
2651 KFAIL_POINT_CODE(DEBUG_FP, fill_kinfo_vnode__random_path,
2656 * Retrieve vnode attributes.
2658 va.va_fsid = VNOVAL;
2660 vn_lock(vp, LK_SHARED | LK_RETRY);
2661 error = VOP_GETATTR(vp, &va, curthread->td_ucred);
2665 if (va.va_fsid != VNOVAL)
2666 kif->kf_un.kf_file.kf_file_fsid = va.va_fsid;
2668 kif->kf_un.kf_file.kf_file_fsid =
2669 vp->v_mount->mnt_stat.f_fsid.val[0];
2670 kif->kf_un.kf_file.kf_file_fsid_freebsd11 =
2671 kif->kf_un.kf_file.kf_file_fsid; /* truncate */
2672 kif->kf_un.kf_file.kf_file_fileid = va.va_fileid;
2673 kif->kf_un.kf_file.kf_file_mode = MAKEIMODE(va.va_type, va.va_mode);
2674 kif->kf_un.kf_file.kf_file_size = va.va_size;
2675 kif->kf_un.kf_file.kf_file_rdev = va.va_rdev;
2676 kif->kf_un.kf_file.kf_file_rdev_freebsd11 =
2677 kif->kf_un.kf_file.kf_file_rdev; /* truncate */
2682 vn_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
2683 vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
2687 struct pmckern_map_in pkm;
2693 boolean_t writecounted;
2696 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
2697 defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
2699 * POSIX shared-memory objects are defined to have
2700 * kernel persistence, and are not defined to support
2701 * read(2)/write(2) -- or even open(2). Thus, we can
2702 * use MAP_ASYNC to trade on-disk coherence for speed.
2703 * The shm_open(3) library routine turns on the FPOSIXSHM
2704 * flag to request this behavior.
2706 if ((fp->f_flag & FPOSIXSHM) != 0)
2707 flags |= MAP_NOSYNC;
2712 * Ensure that file and memory protections are
2713 * compatible. Note that we only worry about
2714 * writability if mapping is shared; in this case,
2715 * current and max prot are dictated by the open file.
2716 * XXX use the vnode instead? Problem is: what
2717 * credentials do we use for determination? What if
2718 * proc does a setuid?
2721 if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) {
2722 maxprot = VM_PROT_NONE;
2723 if ((prot & VM_PROT_EXECUTE) != 0)
2726 maxprot = VM_PROT_EXECUTE;
2727 if ((fp->f_flag & FREAD) != 0)
2728 maxprot |= VM_PROT_READ;
2729 else if ((prot & VM_PROT_READ) != 0)
2733 * If we are sharing potential changes via MAP_SHARED and we
2734 * are trying to get write permission although we opened it
2735 * without asking for it, bail out.
2737 if ((flags & MAP_SHARED) != 0) {
2738 if ((fp->f_flag & FWRITE) != 0)
2739 maxprot |= VM_PROT_WRITE;
2740 else if ((prot & VM_PROT_WRITE) != 0)
2743 maxprot |= VM_PROT_WRITE;
2744 cap_maxprot |= VM_PROT_WRITE;
2746 maxprot &= cap_maxprot;
2749 * For regular files and shared memory, POSIX requires that
2750 * the value of foff be a legitimate offset within the data
2751 * object. In particular, negative offsets are invalid.
2752 * Blocking negative offsets and overflows here avoids
2753 * possible wraparound or user-level access into reserved
2754 * ranges of the data object later. In contrast, POSIX does
2755 * not dictate how offsets are used by device drivers, so in
2756 * the case of a device mapping a negative offset is passed
2763 foff > OFF_MAX - size)
2766 writecounted = FALSE;
2767 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags, vp,
2768 &foff, &object, &writecounted);
2771 error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
2772 foff, writecounted, td);
2775 * If this mapping was accounted for in the vnode's
2776 * writecount, then undo that now.
2779 vm_pager_release_writecount(object, 0, size);
2780 vm_object_deallocate(object);
2783 /* Inform hwpmc(4) if an executable is being mapped. */
2784 if (PMC_HOOK_INSTALLED(PMC_FN_MMAP)) {
2785 if ((prot & VM_PROT_EXECUTE) != 0 && error == 0) {
2787 pkm.pm_address = (uintptr_t) *addr;
2788 PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_MMAP, (void *) &pkm);
2796 vn_fsid(struct vnode *vp, struct vattr *va)
2800 f = &vp->v_mount->mnt_stat.f_fsid;
2801 va->va_fsid = (uint32_t)f->val[1];
2802 va->va_fsid <<= sizeof(f->val[1]) * NBBY;
2803 va->va_fsid += (uint32_t)f->val[0];
2807 vn_fsync_buf(struct vnode *vp, int waitfor)
2809 struct buf *bp, *nbp;
2812 int error, maxretry;
2815 maxretry = 10000; /* large, arbitrarily chosen */
2817 if (vp->v_type == VCHR) {
2819 mp = vp->v_rdev->si_mountpt;
2826 * MARK/SCAN initialization to avoid infinite loops.
2828 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs) {
2829 bp->b_vflags &= ~BV_SCANNED;
2834 * Flush all dirty buffers associated with a vnode.
2837 TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
2838 if ((bp->b_vflags & BV_SCANNED) != 0)
2840 bp->b_vflags |= BV_SCANNED;
2841 if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) {
2842 if (waitfor != MNT_WAIT)
2845 LK_EXCLUSIVE | LK_INTERLOCK | LK_SLEEPFAIL,
2846 BO_LOCKPTR(bo)) != 0) {
2853 KASSERT(bp->b_bufobj == bo,
2854 ("bp %p wrong b_bufobj %p should be %p",
2855 bp, bp->b_bufobj, bo));
2856 if ((bp->b_flags & B_DELWRI) == 0)
2857 panic("fsync: not dirty");
2858 if ((vp->v_object != NULL) && (bp->b_flags & B_CLUSTEROK)) {
2864 if (maxretry < 1000)
2865 pause("dirty", hz < 1000 ? 1 : hz / 1000);
2871 * If synchronous the caller expects us to completely resolve all
2872 * dirty buffers in the system. Wait for in-progress I/O to
2873 * complete (which could include background bitmap writes), then
2874 * retry if dirty blocks still exist.
2876 if (waitfor == MNT_WAIT) {
2877 bufobj_wwait(bo, 0, 0);
2878 if (bo->bo_dirty.bv_cnt > 0) {
2880 * If we are unable to write any of these buffers
2881 * then we fail now rather than trying endlessly
2882 * to write them out.
2884 TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs)
2885 if ((error = bp->b_error) != 0)
2887 if ((mp != NULL && mp->mnt_secondary_writes > 0) ||
2888 (error == 0 && --maxretry >= 0))
2896 vn_printf(vp, "fsync: giving up on dirty (error = %d) ", error);
2902 * Copies a byte range from invp to outvp. Calls VOP_COPY_FILE_RANGE()
2903 * or vn_generic_copy_file_range() after rangelocking the byte ranges,
2904 * to do the actual copy.
2905 * vn_generic_copy_file_range() is factored out, so it can be called
2906 * from a VOP_COPY_FILE_RANGE() call as well, but handles vnodes from
2907 * different file systems.
2910 vn_copy_file_range(struct vnode *invp, off_t *inoffp, struct vnode *outvp,
2911 off_t *outoffp, size_t *lenp, unsigned int flags, struct ucred *incred,
2912 struct ucred *outcred, struct thread *fsize_td)
2919 *lenp = 0; /* For error returns. */
2922 /* Do some sanity checks on the arguments. */
2923 if (invp->v_type == VDIR || outvp->v_type == VDIR)
2925 else if (*inoffp < 0 || *outoffp < 0 ||
2926 invp->v_type != VREG || outvp->v_type != VREG)
2931 /* Ensure offset + len does not wrap around. */
2934 if (uval > INT64_MAX)
2935 len = INT64_MAX - *inoffp;
2938 if (uval > INT64_MAX)
2939 len = INT64_MAX - *outoffp;
2944 * If the two vnode are for the same file system, call
2945 * VOP_COPY_FILE_RANGE(), otherwise call vn_generic_copy_file_range()
2946 * which can handle copies across multiple file systems.
2949 if (invp->v_mount == outvp->v_mount)
2950 error = VOP_COPY_FILE_RANGE(invp, inoffp, outvp, outoffp,
2951 lenp, flags, incred, outcred, fsize_td);
2953 error = vn_generic_copy_file_range(invp, inoffp, outvp,
2954 outoffp, lenp, flags, incred, outcred, fsize_td);
2960 * Test len bytes of data starting at dat for all bytes == 0.
2961 * Return true if all bytes are zero, false otherwise.
2962 * Expects dat to be well aligned.
2965 mem_iszero(void *dat, int len)
2971 for (p = dat; len > 0; len -= sizeof(*p), p++) {
2972 if (len >= sizeof(*p)) {
2976 cp = (const char *)p;
2977 for (i = 0; i < len; i++, cp++)
2986 * Look for a hole in the output file and, if found, adjust *outoffp
2987 * and *xferp to skip past the hole.
2988 * *xferp is the entire hole length to be written and xfer2 is how many bytes
2989 * to be written as 0's upon return.
2992 vn_skip_hole(struct vnode *outvp, off_t xfer2, off_t *outoffp, off_t *xferp,
2993 off_t *dataoffp, off_t *holeoffp, struct ucred *cred)
2998 if (*holeoffp == 0 || *holeoffp <= *outoffp) {
2999 *dataoffp = *outoffp;
3000 error = VOP_IOCTL(outvp, FIOSEEKDATA, dataoffp, 0, cred,
3003 *holeoffp = *dataoffp;
3004 error = VOP_IOCTL(outvp, FIOSEEKHOLE, holeoffp, 0, cred,
3007 if (error != 0 || *holeoffp == *dataoffp) {
3009 * Since outvp is unlocked, it may be possible for
3010 * another thread to do a truncate(), lseek(), write()
3011 * creating a hole at startoff between the above
3012 * VOP_IOCTL() calls, if the other thread does not do
3014 * If that happens, *holeoffp == *dataoffp and finding
3015 * the hole has failed, so disable vn_skip_hole().
3017 *holeoffp = -1; /* Disable use of vn_skip_hole(). */
3020 KASSERT(*dataoffp >= *outoffp,
3021 ("vn_skip_hole: dataoff=%jd < outoff=%jd",
3022 (intmax_t)*dataoffp, (intmax_t)*outoffp));
3023 KASSERT(*holeoffp > *dataoffp,
3024 ("vn_skip_hole: holeoff=%jd <= dataoff=%jd",
3025 (intmax_t)*holeoffp, (intmax_t)*dataoffp));
3029 * If there is a hole before the data starts, advance *outoffp and
3030 * *xferp past the hole.
3032 if (*dataoffp > *outoffp) {
3033 delta = *dataoffp - *outoffp;
3034 if (delta >= *xferp) {
3035 /* Entire *xferp is a hole. */
3042 xfer2 = MIN(xfer2, *xferp);
3046 * If a hole starts before the end of this xfer2, reduce this xfer2 so
3047 * that the write ends at the start of the hole.
3048 * *holeoffp should always be greater than *outoffp, but for the
3049 * non-INVARIANTS case, check this to make sure xfer2 remains a sane
3052 if (*holeoffp > *outoffp && *holeoffp < *outoffp + xfer2)
3053 xfer2 = *holeoffp - *outoffp;
3058 * Write an xfer sized chunk to outvp in blksize blocks from dat.
3059 * dat is a maximum of blksize in length and can be written repeatedly in
3061 * If growfile == true, just grow the file via vn_truncate_locked() instead
3062 * of doing actual writes.
3063 * If checkhole == true, a hole is being punched, so skip over any hole
3064 * already in the output file.
3067 vn_write_outvp(struct vnode *outvp, char *dat, off_t outoff, off_t xfer,
3068 u_long blksize, bool growfile, bool checkhole, struct ucred *cred)
3071 off_t dataoff, holeoff, xfer2;
3075 * Loop around doing writes of blksize until write has been completed.
3076 * Lock/unlock on each loop iteration so that a bwillwrite() can be
3077 * done for each iteration, since the xfer argument can be very
3078 * large if there is a large hole to punch in the output file.
3083 xfer2 = MIN(xfer, blksize);
3086 * Punching a hole. Skip writing if there is
3087 * already a hole in the output file.
3089 xfer2 = vn_skip_hole(outvp, xfer2, &outoff, &xfer,
3090 &dataoff, &holeoff, cred);
3095 KASSERT(xfer2 > 0, ("vn_write_outvp: xfer2=%jd",
3100 error = vn_start_write(outvp, &mp, V_WAIT);
3104 error = vn_lock(outvp, LK_EXCLUSIVE);
3106 error = vn_truncate_locked(outvp, outoff + xfer,
3111 error = vn_lock(outvp, vn_lktype_write(mp, outvp));
3113 error = vn_rdwr(UIO_WRITE, outvp, dat, xfer2,
3114 outoff, UIO_SYSSPACE, IO_NODELOCKED,
3115 curthread->td_ucred, cred, NULL, curthread);
3122 vn_finished_write(mp);
3123 } while (!growfile && xfer > 0 && error == 0);
3128 * Copy a byte range of one file to another. This function can handle the
3129 * case where invp and outvp are on different file systems.
3130 * It can also be called by a VOP_COPY_FILE_RANGE() to do the work, if there
3131 * is no better file system specific way to do it.
3134 vn_generic_copy_file_range(struct vnode *invp, off_t *inoffp,
3135 struct vnode *outvp, off_t *outoffp, size_t *lenp, unsigned int flags,
3136 struct ucred *incred, struct ucred *outcred, struct thread *fsize_td)
3138 struct vattr va, inva;
3141 off_t startoff, endoff, xfer, xfer2;
3143 int error, interrupted;
3144 bool cantseek, readzeros, eof, lastblock, holetoeof;
3146 size_t copylen, len, rem, savlen;
3148 long holein, holeout;
3150 holein = holeout = 0;
3151 savlen = len = *lenp;
3156 error = vn_lock(invp, LK_SHARED);
3159 if (VOP_PATHCONF(invp, _PC_MIN_HOLE_SIZE, &holein) != 0)
3162 error = VOP_GETATTR(invp, &inva, incred);
3168 error = vn_start_write(outvp, &mp, V_WAIT);
3170 error = vn_lock(outvp, LK_EXCLUSIVE);
3173 * If fsize_td != NULL, do a vn_rlimit_fsize() call,
3174 * now that outvp is locked.
3176 if (fsize_td != NULL) {
3177 io.uio_offset = *outoffp;
3179 error = vn_rlimit_fsize(outvp, &io, fsize_td);
3183 if (VOP_PATHCONF(outvp, _PC_MIN_HOLE_SIZE, &holeout) != 0)
3186 * Holes that are past EOF do not need to be written as a block
3187 * of zero bytes. So, truncate the output file as far as
3188 * possible and then use va.va_size to decide if writing 0
3189 * bytes is necessary in the loop below.
3192 error = VOP_GETATTR(outvp, &va, outcred);
3193 if (error == 0 && va.va_size > *outoffp && va.va_size <=
3196 error = mac_vnode_check_write(curthread->td_ucred,
3200 error = vn_truncate_locked(outvp, *outoffp,
3203 va.va_size = *outoffp;
3208 vn_finished_write(mp);
3213 * Set the blksize to the larger of the hole sizes for invp and outvp.
3214 * If hole sizes aren't available, set the blksize to the larger
3215 * f_iosize of invp and outvp.
3216 * This code expects the hole sizes and f_iosizes to be powers of 2.
3217 * This value is clipped at 4Kbytes and 1Mbyte.
3219 blksize = MAX(holein, holeout);
3221 /* Clip len to end at an exact multiple of hole size. */
3223 rem = *inoffp % blksize;
3225 rem = blksize - rem;
3226 if (len > rem && len - rem > blksize)
3227 len = savlen = rounddown(len - rem, blksize) + rem;
3231 blksize = MAX(invp->v_mount->mnt_stat.f_iosize,
3232 outvp->v_mount->mnt_stat.f_iosize);
3235 else if (blksize > 1024 * 1024)
3236 blksize = 1024 * 1024;
3237 dat = malloc(blksize, M_TEMP, M_WAITOK);
3240 * If VOP_IOCTL(FIOSEEKHOLE) works for invp, use it and FIOSEEKDATA
3241 * to find holes. Otherwise, just scan the read block for all 0s
3242 * in the inner loop where the data copying is done.
3243 * Note that some file systems such as NFSv3, NFSv4.0 and NFSv4.1 may
3244 * support holes on the server, but do not support FIOSEEKHOLE.
3246 holetoeof = eof = false;
3247 while (len > 0 && error == 0 && !eof && interrupted == 0) {
3248 endoff = 0; /* To shut up compilers. */
3254 * Find the next data area. If there is just a hole to EOF,
3255 * FIOSEEKDATA should fail with ENXIO.
3256 * (I do not know if any file system will report a hole to
3257 * EOF via FIOSEEKHOLE, but I am pretty sure FIOSEEKDATA
3258 * will fail for those file systems.)
3260 * For input files that don't support FIOSEEKDATA/FIOSEEKHOLE,
3261 * the code just falls through to the inner copy loop.
3265 error = VOP_IOCTL(invp, FIOSEEKDATA, &startoff, 0,
3267 if (error == ENXIO) {
3268 startoff = endoff = inva.va_size;
3269 eof = holetoeof = true;
3273 if (error == 0 && !holetoeof) {
3275 error = VOP_IOCTL(invp, FIOSEEKHOLE, &endoff, 0,
3278 * Since invp is unlocked, it may be possible for
3279 * another thread to do a truncate(), lseek(), write()
3280 * creating a hole at startoff between the above
3281 * VOP_IOCTL() calls, if the other thread does not do
3283 * If that happens, startoff == endoff and finding
3284 * the hole has failed, so set an error.
3286 if (error == 0 && startoff == endoff)
3287 error = EINVAL; /* Any error. Reset to 0. */
3290 if (startoff > *inoffp) {
3291 /* Found hole before data block. */
3292 xfer = MIN(startoff - *inoffp, len);
3293 if (*outoffp < va.va_size) {
3294 /* Must write 0s to punch hole. */
3295 xfer2 = MIN(va.va_size - *outoffp,
3297 memset(dat, 0, MIN(xfer2, blksize));
3298 error = vn_write_outvp(outvp, dat,
3299 *outoffp, xfer2, blksize, false,
3300 holeout > 0, outcred);
3303 if (error == 0 && *outoffp + xfer >
3304 va.va_size && (xfer == len || holetoeof)) {
3305 /* Grow output file (hole at end). */
3306 error = vn_write_outvp(outvp, dat,
3307 *outoffp, xfer, blksize, true,
3315 interrupted = sig_intr();
3318 copylen = MIN(len, endoff - startoff);
3330 * Set first xfer to end at a block boundary, so that
3331 * holes are more likely detected in the loop below via
3332 * the for all bytes 0 method.
3334 xfer -= (*inoffp % blksize);
3336 /* Loop copying the data block. */
3337 while (copylen > 0 && error == 0 && !eof && interrupted == 0) {
3340 error = vn_lock(invp, LK_SHARED);
3343 error = vn_rdwr(UIO_READ, invp, dat, xfer,
3344 startoff, UIO_SYSSPACE, IO_NODELOCKED,
3345 curthread->td_ucred, incred, &aresid,
3349 if (error == 0 && aresid > 0) {
3350 /* Stop the copy at EOF on the input file. */
3357 * Skip the write for holes past the initial EOF
3358 * of the output file, unless this is the last
3359 * write of the output file at EOF.
3361 readzeros = cantseek ? mem_iszero(dat, xfer) :
3365 if (!cantseek || *outoffp < va.va_size ||
3366 lastblock || !readzeros)
3367 error = vn_write_outvp(outvp, dat,
3368 *outoffp, xfer, blksize,
3369 readzeros && lastblock &&
3370 *outoffp >= va.va_size, false,
3379 interrupted = sig_intr();
3386 *lenp = savlen - len;
3392 vn_fallocate(struct file *fp, off_t offset, off_t len, struct thread *td)
3396 off_t olen, ooffset;
3399 int audited_vnode1 = 0;
3403 if (vp->v_type != VREG)
3406 /* Allocating blocks may take a long time, so iterate. */
3413 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
3416 error = vn_lock(vp, LK_EXCLUSIVE);
3418 vn_finished_write(mp);
3422 if (!audited_vnode1) {
3423 AUDIT_ARG_VNODE1(vp);
3428 error = mac_vnode_check_write(td->td_ucred, fp->f_cred, vp);
3431 error = VOP_ALLOCATE(vp, &offset, &len);
3433 vn_finished_write(mp);
3435 if (olen + ooffset != offset + len) {
3436 panic("offset + len changed from %jx/%jx to %jx/%jx",
3437 ooffset, olen, offset, len);
3439 if (error != 0 || len == 0)
3441 KASSERT(olen > len, ("Iteration did not make progress?"));
3449 vn_deallocate_impl(struct vnode *vp, off_t *offset, off_t *length, int flags,
3450 int ioflag, struct ucred *active_cred, struct ucred *file_cred)
3457 bool audited_vnode1 = false;
3466 if ((ioflag & (IO_NODELOCKED | IO_RANGELOCKED)) == 0)
3467 rl_cookie = vn_rangelock_wlock(vp, off, off + len);
3468 while (len > 0 && error == 0) {
3470 * Try to deallocate the longest range in one pass.
3471 * In case a pass takes too long to be executed, it returns
3472 * partial result. The residue will be proceeded in the next
3476 if ((ioflag & IO_NODELOCKED) == 0) {
3478 if ((error = vn_start_write(vp, &mp,
3479 V_WAIT | PCATCH)) != 0)
3481 vn_lock(vp, vn_lktype_write(mp, vp) | LK_RETRY);
3484 if (!audited_vnode1) {
3485 AUDIT_ARG_VNODE1(vp);
3486 audited_vnode1 = true;
3491 if ((ioflag & IO_NOMACCHECK) == 0)
3492 error = mac_vnode_check_write(active_cred, file_cred,
3496 error = VOP_DEALLOCATE(vp, &off, &len, flags,
3499 if ((ioflag & IO_NODELOCKED) == 0) {
3502 vn_finished_write(mp);
3508 if (rl_cookie != NULL)
3509 vn_rangelock_unlock(vp, rl_cookie);
3516 vn_deallocate(struct vnode *vp, off_t *offset, off_t *length, int flags,
3517 int ioflag, struct ucred *active_cred, struct ucred *file_cred)
3519 if (*offset < 0 || *length <= 0 || *length > OFF_MAX - *offset ||
3522 if (vp->v_type != VREG)
3525 return (vn_deallocate_impl(vp, offset, length, flags, ioflag,
3526 active_cred, file_cred));
3530 vn_fspacectl(struct file *fp, int cmd, off_t *offset, off_t *length, int flags,
3531 struct ucred *active_cred, struct thread *td)
3538 if (cmd != SPACECTL_DEALLOC || *offset < 0 || *length <= 0 ||
3539 *length > OFF_MAX - *offset || flags != 0)
3541 if (vp->v_type != VREG)
3545 case SPACECTL_DEALLOC:
3546 error = vn_deallocate_impl(vp, offset, length, flags, 0,
3547 active_cred, fp->f_cred);
3550 panic("vn_fspacectl: unknown cmd %d", cmd);
3556 static u_long vn_lock_pair_pause_cnt;
3557 SYSCTL_ULONG(_debug, OID_AUTO, vn_lock_pair_pause, CTLFLAG_RD,
3558 &vn_lock_pair_pause_cnt, 0,
3559 "Count of vn_lock_pair deadlocks");
3561 u_int vn_lock_pair_pause_max;
3562 SYSCTL_UINT(_debug, OID_AUTO, vn_lock_pair_pause_max, CTLFLAG_RW,
3563 &vn_lock_pair_pause_max, 0,
3564 "Max ticks for vn_lock_pair deadlock avoidance sleep");
3567 vn_lock_pair_pause(const char *wmesg)
3569 atomic_add_long(&vn_lock_pair_pause_cnt, 1);
3570 pause(wmesg, prng32_bounded(vn_lock_pair_pause_max));
3574 * Lock pair of vnodes vp1, vp2, avoiding lock order reversal.
3575 * vp1_locked indicates whether vp1 is exclusively locked; if not, vp1
3576 * must be unlocked. Same for vp2 and vp2_locked. One of the vnodes
3579 * The function returns with both vnodes exclusively locked, and
3580 * guarantees that it does not create lock order reversal with other
3581 * threads during its execution. Both vnodes could be unlocked
3582 * temporary (and reclaimed).
3585 vn_lock_pair(struct vnode *vp1, bool vp1_locked, struct vnode *vp2,
3590 if (vp1 == NULL && vp2 == NULL)
3594 ASSERT_VOP_ELOCKED(vp1, "vp1");
3596 ASSERT_VOP_UNLOCKED(vp1, "vp1");
3602 ASSERT_VOP_ELOCKED(vp2, "vp2");
3604 ASSERT_VOP_UNLOCKED(vp2, "vp2");
3608 if (!vp1_locked && !vp2_locked) {
3609 vn_lock(vp1, LK_EXCLUSIVE | LK_RETRY);
3614 if (vp1_locked && vp2_locked)
3616 if (vp1_locked && vp2 != NULL) {
3618 error = VOP_LOCK1(vp2, LK_EXCLUSIVE | LK_NOWAIT,
3619 __FILE__, __LINE__);
3624 vn_lock_pair_pause("vlp1");
3626 vn_lock(vp2, LK_EXCLUSIVE | LK_RETRY);
3629 if (vp2_locked && vp1 != NULL) {
3631 error = VOP_LOCK1(vp1, LK_EXCLUSIVE | LK_NOWAIT,
3632 __FILE__, __LINE__);
3637 vn_lock_pair_pause("vlp2");
3639 vn_lock(vp1, LK_EXCLUSIVE | LK_RETRY);
3644 ASSERT_VOP_ELOCKED(vp1, "vp1 ret");
3646 ASSERT_VOP_ELOCKED(vp2, "vp2 ret");
3650 vn_lktype_write(struct mount *mp, struct vnode *vp)
3652 if (MNT_SHARED_WRITES(mp) ||
3653 (mp == NULL && MNT_SHARED_WRITES(vp->v_mount)))
3655 return (LK_EXCLUSIVE);