636 lines
14 KiB
C
636 lines
14 KiB
C
/* $NetBSD: vfs_vnops.c,v 1.42 2000/04/11 04:37:51 chs Exp $ */
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/*
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* Copyright (c) 1982, 1986, 1989, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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* All or some portions of this file are derived from material licensed
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* to the University of California by American Telephone and Telegraph
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* Co. or Unix System Laboratories, Inc. and are reproduced herein with
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* the permission of UNIX System Laboratories, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)vfs_vnops.c 8.14 (Berkeley) 6/15/95
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*/
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#include "fs_union.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/file.h>
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#include <sys/stat.h>
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#include <sys/buf.h>
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#include <sys/proc.h>
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#include <sys/mount.h>
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#include <sys/namei.h>
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#include <sys/vnode.h>
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#include <sys/ioctl.h>
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#include <sys/tty.h>
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#include <sys/poll.h>
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#include <vm/vm.h>
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#include <uvm/uvm_extern.h>
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#ifdef UNION
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#include <miscfs/union/union.h>
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#endif
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struct fileops vnops =
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{ vn_read, vn_write, vn_ioctl, vn_fcntl, vn_poll, vn_closefile };
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/*
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* Common code for vnode open operations.
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* Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
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*/
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int
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vn_open(ndp, fmode, cmode)
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struct nameidata *ndp;
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int fmode, cmode;
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{
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struct vnode *vp;
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struct proc *p = ndp->ni_cnd.cn_proc;
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struct ucred *cred = p->p_ucred;
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struct vattr va;
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int error;
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if (fmode & O_CREAT) {
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ndp->ni_cnd.cn_nameiop = CREATE;
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ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF;
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if ((fmode & O_EXCL) == 0 &&
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((fmode & FNOSYMLINK) == 0))
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ndp->ni_cnd.cn_flags |= FOLLOW;
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if ((error = namei(ndp)) != 0)
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return (error);
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if (ndp->ni_vp == NULL) {
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VATTR_NULL(&va);
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va.va_type = VREG;
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va.va_mode = cmode;
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if (fmode & O_EXCL)
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va.va_vaflags |= VA_EXCLUSIVE;
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VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE);
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error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
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&ndp->ni_cnd, &va);
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if (error)
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return (error);
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fmode &= ~O_TRUNC;
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vp = ndp->ni_vp;
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} else {
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VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd);
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if (ndp->ni_dvp == ndp->ni_vp)
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vrele(ndp->ni_dvp);
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else
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vput(ndp->ni_dvp);
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ndp->ni_dvp = NULL;
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vp = ndp->ni_vp;
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if (fmode & O_EXCL) {
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error = EEXIST;
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goto bad;
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}
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if (ndp->ni_vp->v_type == VLNK) {
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error = EFTYPE;
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goto bad;
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}
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fmode &= ~O_CREAT;
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}
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} else {
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ndp->ni_cnd.cn_nameiop = LOOKUP;
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ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF;
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if ((error = namei(ndp)) != 0)
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return (error);
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vp = ndp->ni_vp;
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}
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if (vp->v_type == VSOCK) {
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error = EOPNOTSUPP;
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goto bad;
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}
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if ((fmode & O_CREAT) == 0) {
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if (fmode & FREAD) {
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if ((error = VOP_ACCESS(vp, VREAD, cred, p)) != 0)
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goto bad;
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}
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if (fmode & (FWRITE | O_TRUNC)) {
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if (vp->v_type == VDIR) {
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error = EISDIR;
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goto bad;
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}
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if ((error = vn_writechk(vp)) != 0 ||
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(error = VOP_ACCESS(vp, VWRITE, cred, p)) != 0)
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goto bad;
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}
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}
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if (fmode & O_TRUNC) {
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VOP_UNLOCK(vp, 0); /* XXX */
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VOP_LEASE(vp, p, cred, LEASE_WRITE);
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); /* XXX */
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VATTR_NULL(&va);
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va.va_size = 0;
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if ((error = VOP_SETATTR(vp, &va, cred, p)) != 0)
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goto bad;
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}
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if ((error = VOP_OPEN(vp, fmode, cred, p)) != 0)
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goto bad;
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if (fmode & FWRITE)
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vp->v_writecount++;
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return (0);
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bad:
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vput(vp);
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return (error);
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}
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/*
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* Check for write permissions on the specified vnode.
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* Prototype text segments cannot be written.
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*/
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int
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vn_writechk(vp)
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struct vnode *vp;
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{
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/*
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* If there's shared text associated with
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* the vnode, try to free it up once. If
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* we fail, we can't allow writing.
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*/
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if ((vp->v_flag & VTEXT) && !uvm_vnp_uncache(vp))
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return (ETXTBSY);
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return (0);
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}
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/*
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* Mark a vnode as being the text image of a running process.
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*/
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void
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vn_marktext(vp)
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struct vnode *vp;
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{
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vp->v_flag |= VTEXT;
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}
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/*
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* Vnode close call
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*
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* Note: takes an unlocked vnode, while VOP_CLOSE takes a locked node.
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*/
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int
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vn_close(vp, flags, cred, p)
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struct vnode *vp;
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int flags;
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struct ucred *cred;
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struct proc *p;
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{
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int error;
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if (flags & FWRITE)
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vp->v_writecount--;
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
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error = VOP_CLOSE(vp, flags, cred, p);
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vput(vp);
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return (error);
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}
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/*
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* Package up an I/O request on a vnode into a uio and do it.
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*/
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int
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vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, cred, aresid, p)
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enum uio_rw rw;
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struct vnode *vp;
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caddr_t base;
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int len;
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off_t offset;
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enum uio_seg segflg;
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int ioflg;
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struct ucred *cred;
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size_t *aresid;
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struct proc *p;
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{
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struct uio auio;
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struct iovec aiov;
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int error;
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if ((ioflg & IO_NODELOCKED) == 0)
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
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auio.uio_iov = &aiov;
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auio.uio_iovcnt = 1;
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aiov.iov_base = base;
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aiov.iov_len = len;
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auio.uio_resid = len;
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auio.uio_offset = offset;
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auio.uio_segflg = segflg;
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auio.uio_rw = rw;
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auio.uio_procp = p;
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if (rw == UIO_READ) {
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error = VOP_READ(vp, &auio, ioflg, cred);
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} else {
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error = VOP_WRITE(vp, &auio, ioflg, cred);
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}
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if (aresid)
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*aresid = auio.uio_resid;
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else
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if (auio.uio_resid && error == 0)
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error = EIO;
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if ((ioflg & IO_NODELOCKED) == 0)
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VOP_UNLOCK(vp, 0);
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return (error);
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}
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int
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vn_readdir(fp, buf, segflg, count, done, p, cookies, ncookies)
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struct file *fp;
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char *buf;
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int segflg, *done, *ncookies;
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u_int count;
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struct proc *p;
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off_t **cookies;
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{
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struct vnode *vp = (struct vnode *)fp->f_data;
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struct iovec aiov;
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struct uio auio;
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int error, eofflag;
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unionread:
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if (vp->v_type != VDIR)
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return (EINVAL);
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aiov.iov_base = buf;
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aiov.iov_len = count;
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auio.uio_iov = &aiov;
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auio.uio_iovcnt = 1;
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auio.uio_rw = UIO_READ;
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auio.uio_segflg = segflg;
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auio.uio_procp = p;
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auio.uio_resid = count;
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
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auio.uio_offset = fp->f_offset;
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error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies,
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ncookies);
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fp->f_offset = auio.uio_offset;
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VOP_UNLOCK(vp, 0);
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if (error)
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return (error);
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#ifdef UNION
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{
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extern struct vnode *union_dircache __P((struct vnode *));
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if (count == auio.uio_resid && (vp->v_op == union_vnodeop_p)) {
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struct vnode *lvp;
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lvp = union_dircache(vp);
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if (lvp != NULLVP) {
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struct vattr va;
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/*
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* If the directory is opaque,
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* then don't show lower entries
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*/
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error = VOP_GETATTR(vp, &va, fp->f_cred, p);
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if (va.va_flags & OPAQUE) {
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vput(lvp);
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lvp = NULL;
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}
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}
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if (lvp != NULLVP) {
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error = VOP_OPEN(lvp, FREAD, fp->f_cred, p);
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if (error) {
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vput(lvp);
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return (error);
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}
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VOP_UNLOCK(lvp, 0);
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fp->f_data = (caddr_t) lvp;
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fp->f_offset = 0;
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error = vn_close(vp, FREAD, fp->f_cred, p);
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if (error)
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return (error);
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vp = lvp;
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goto unionread;
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}
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}
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}
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#endif /* UNION */
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if (count == auio.uio_resid && (vp->v_flag & VROOT) &&
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(vp->v_mount->mnt_flag & MNT_UNION)) {
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struct vnode *tvp = vp;
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vp = vp->v_mount->mnt_vnodecovered;
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VREF(vp);
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fp->f_data = (caddr_t) vp;
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fp->f_offset = 0;
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vrele(tvp);
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goto unionread;
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}
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*done = count - auio.uio_resid;
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return error;
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}
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/*
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* File table vnode read routine.
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*/
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int
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vn_read(fp, offset, uio, cred, flags)
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struct file *fp;
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off_t *offset;
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struct uio *uio;
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struct ucred *cred;
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int flags;
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{
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struct vnode *vp = (struct vnode *)fp->f_data;
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int count, error, ioflag = 0;
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VOP_LEASE(vp, uio->uio_procp, cred, LEASE_READ);
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if (fp->f_flag & FNONBLOCK)
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ioflag |= IO_NDELAY;
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if ((fp->f_flag & (FFSYNC | FRSYNC)) == (FFSYNC | FRSYNC))
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ioflag |= IO_SYNC;
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if (fp->f_flag & FALTIO)
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ioflag |= IO_ALTSEMANTICS;
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
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uio->uio_offset = *offset;
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count = uio->uio_resid;
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error = VOP_READ(vp, uio, ioflag, cred);
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if (flags & FOF_UPDATE_OFFSET)
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*offset += count - uio->uio_resid;
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VOP_UNLOCK(vp, 0);
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return (error);
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}
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/*
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* File table vnode write routine.
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*/
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int
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vn_write(fp, offset, uio, cred, flags)
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struct file *fp;
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off_t *offset;
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struct uio *uio;
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struct ucred *cred;
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int flags;
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{
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struct vnode *vp = (struct vnode *)fp->f_data;
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int count, error, ioflag = IO_UNIT;
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if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
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ioflag |= IO_APPEND;
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if (fp->f_flag & FNONBLOCK)
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ioflag |= IO_NDELAY;
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if (fp->f_flag & FFSYNC ||
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(vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
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ioflag |= IO_SYNC;
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else if (fp->f_flag & FDSYNC)
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ioflag |= IO_DSYNC;
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if (fp->f_flag & FALTIO)
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ioflag |= IO_ALTSEMANTICS;
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VOP_LEASE(vp, uio->uio_procp, cred, LEASE_WRITE);
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
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uio->uio_offset = *offset;
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count = uio->uio_resid;
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error = VOP_WRITE(vp, uio, ioflag, cred);
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if (flags & FOF_UPDATE_OFFSET) {
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if (ioflag & IO_APPEND)
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*offset = uio->uio_offset;
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else
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*offset += count - uio->uio_resid;
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}
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VOP_UNLOCK(vp, 0);
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return (error);
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}
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/*
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* File table vnode stat routine.
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*/
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int
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vn_stat(vp, sb, p)
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struct vnode *vp;
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struct stat *sb;
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struct proc *p;
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{
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struct vattr va;
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int error;
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mode_t mode;
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error = VOP_GETATTR(vp, &va, p->p_ucred, p);
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if (error)
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return (error);
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/*
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* Copy from vattr table
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*/
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sb->st_dev = va.va_fsid;
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sb->st_ino = va.va_fileid;
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mode = va.va_mode;
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switch (vp->v_type) {
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case VREG:
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mode |= S_IFREG;
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break;
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case VDIR:
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mode |= S_IFDIR;
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break;
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case VBLK:
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mode |= S_IFBLK;
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break;
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case VCHR:
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mode |= S_IFCHR;
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break;
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case VLNK:
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mode |= S_IFLNK;
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break;
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case VSOCK:
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mode |= S_IFSOCK;
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break;
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case VFIFO:
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mode |= S_IFIFO;
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break;
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default:
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return (EBADF);
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};
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sb->st_mode = mode;
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sb->st_nlink = va.va_nlink;
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sb->st_uid = va.va_uid;
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sb->st_gid = va.va_gid;
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sb->st_rdev = va.va_rdev;
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sb->st_size = va.va_size;
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sb->st_atimespec = va.va_atime;
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sb->st_mtimespec = va.va_mtime;
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sb->st_ctimespec = va.va_ctime;
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sb->st_blksize = va.va_blocksize;
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sb->st_flags = va.va_flags;
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sb->st_gen = 0;
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sb->st_blocks = va.va_bytes / S_BLKSIZE;
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return (0);
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}
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/*
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* File table vnode fcntl routine.
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*/
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int
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vn_fcntl(fp, com, data, p)
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struct file *fp;
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u_int com;
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caddr_t data;
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struct proc *p;
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{
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struct vnode *vp = ((struct vnode *)fp->f_data);
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int error;
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
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error = VOP_FCNTL(vp, com, data, fp->f_flag, p->p_ucred, p);
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VOP_UNLOCK(vp, 0);
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return (error);
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}
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/*
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* File table vnode ioctl routine.
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*/
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int
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|
vn_ioctl(fp, com, data, p)
|
|
struct file *fp;
|
|
u_long com;
|
|
caddr_t data;
|
|
struct proc *p;
|
|
{
|
|
struct vnode *vp = ((struct vnode *)fp->f_data);
|
|
struct vattr vattr;
|
|
int error;
|
|
|
|
switch (vp->v_type) {
|
|
|
|
case VREG:
|
|
case VDIR:
|
|
if (com == FIONREAD) {
|
|
error = VOP_GETATTR(vp, &vattr, p->p_ucred, p);
|
|
if (error)
|
|
return (error);
|
|
*(int *)data = vattr.va_size - fp->f_offset;
|
|
return (0);
|
|
}
|
|
if (com == FIONBIO || com == FIOASYNC) /* XXX */
|
|
return (0); /* XXX */
|
|
/* fall into ... */
|
|
|
|
default:
|
|
return (ENOTTY);
|
|
|
|
case VFIFO:
|
|
case VCHR:
|
|
case VBLK:
|
|
error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p);
|
|
if (error == 0 && com == TIOCSCTTY) {
|
|
if (p->p_session->s_ttyvp)
|
|
vrele(p->p_session->s_ttyvp);
|
|
p->p_session->s_ttyvp = vp;
|
|
VREF(vp);
|
|
}
|
|
return (error);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* File table vnode poll routine.
|
|
*/
|
|
int
|
|
vn_poll(fp, events, p)
|
|
struct file *fp;
|
|
int events;
|
|
struct proc *p;
|
|
{
|
|
|
|
return (VOP_POLL(((struct vnode *)fp->f_data), events, p));
|
|
}
|
|
|
|
/*
|
|
* Check that the vnode is still valid, and if so
|
|
* acquire requested lock.
|
|
*/
|
|
int
|
|
vn_lock(vp, flags)
|
|
struct vnode *vp;
|
|
int flags;
|
|
{
|
|
int error;
|
|
|
|
do {
|
|
if ((flags & LK_INTERLOCK) == 0)
|
|
simple_lock(&vp->v_interlock);
|
|
if (vp->v_flag & VXLOCK) {
|
|
vp->v_flag |= VXWANT;
|
|
simple_unlock(&vp->v_interlock);
|
|
tsleep((caddr_t)vp, PINOD, "vn_lock", 0);
|
|
error = ENOENT;
|
|
} else {
|
|
error = VOP_LOCK(vp, flags | LK_INTERLOCK);
|
|
if (error == 0 || error == EDEADLK)
|
|
return (error);
|
|
}
|
|
flags &= ~LK_INTERLOCK;
|
|
} while (flags & LK_RETRY);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* File table vnode close routine.
|
|
*/
|
|
int
|
|
vn_closefile(fp, p)
|
|
struct file *fp;
|
|
struct proc *p;
|
|
{
|
|
|
|
return (vn_close(((struct vnode *)fp->f_data), fp->f_flag,
|
|
fp->f_cred, p));
|
|
}
|
|
|
|
/*
|
|
* Enable LK_CANRECURSE on lock. Return prior status.
|
|
*/
|
|
u_int
|
|
vn_setrecurse(vp)
|
|
struct vnode *vp;
|
|
{
|
|
struct lock *lkp = &vp->v_lock;
|
|
u_int retval = lkp->lk_flags & LK_CANRECURSE;
|
|
|
|
lkp->lk_flags |= LK_CANRECURSE;
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* Called when done with locksetrecurse.
|
|
*/
|
|
void
|
|
vn_restorerecurse(vp, flags)
|
|
struct vnode *vp;
|
|
u_int flags;
|
|
{
|
|
struct lock *lkp = &vp->v_lock;
|
|
|
|
lkp->lk_flags &= ~LK_CANRECURSE;
|
|
lkp->lk_flags |= flags;
|
|
}
|