542 lines
12 KiB
C
542 lines
12 KiB
C
/*
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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 8.2 (Berkeley) 1/21/94
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* $Id: vfs_vnops.c,v 1.35 1997/04/04 17:46:21 dfr Exp $
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*/
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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/fcntl.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/filio.h>
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#include <sys/ttycom.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/vm_object.h>
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#include <vm/vnode_pager.h>
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static int vn_closefile __P((struct file *fp, struct proc *p));
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static int vn_ioctl __P((struct file *fp, int com, caddr_t data,
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struct proc *p));
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static int vn_read __P((struct file *fp, struct uio *uio,
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struct ucred *cred));
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static int vn_select __P((struct file *fp, int which, struct proc *p));
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static int vn_write __P((struct file *fp, struct uio *uio,
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struct ucred *cred));
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struct fileops vnops =
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{ vn_read, vn_write, vn_ioctl, vn_select, 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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register struct nameidata *ndp;
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int fmode, cmode;
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{
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register struct vnode *vp;
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register struct proc *p = ndp->ni_cnd.cn_proc;
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register struct ucred *cred = p->p_ucred;
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struct vattr vat;
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struct vattr *vap = &vat;
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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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ndp->ni_cnd.cn_flags |= FOLLOW;
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error = namei(ndp);
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if (error)
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return (error);
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if (ndp->ni_vp == NULL) {
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VATTR_NULL(vap);
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vap->va_type = VREG;
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vap->va_mode = cmode;
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if (fmode & O_EXCL)
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vap->va_vaflags |= VA_EXCLUSIVE;
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VOP_LEASE(ndp->ni_dvp, p, cred, LEASE_WRITE);
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if (error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
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&ndp->ni_cnd, vap))
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return (error);
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ASSERT_VOP_UNLOCKED(ndp->ni_dvp, "create");
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ASSERT_VOP_LOCKED(ndp->ni_vp, "create");
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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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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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error = namei(ndp);
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if (error)
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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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error = VOP_ACCESS(vp, VREAD, cred, p);
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if (error)
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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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error = vn_writechk(vp);
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if (error)
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goto bad;
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error = VOP_ACCESS(vp, VWRITE, cred, p);
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if (error)
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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, p); /* XXX */
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VOP_LEASE(vp, p, cred, LEASE_WRITE);
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); /* XXX */
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VATTR_NULL(vap);
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vap->va_size = 0;
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error = VOP_SETATTR(vp, vap, cred, p);
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if (error)
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goto bad;
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}
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error = VOP_OPEN(vp, fmode, cred, p);
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if (error)
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goto bad;
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/*
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* Make sure that a VM object is created for VMIO support.
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*/
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if (vp->v_type == VREG) {
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if ((error = vfs_object_create(vp, p, cred, 1)) != 0)
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goto bad;
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}
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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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register 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)
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return (ETXTBSY);
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return (0);
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}
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/*
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* Vnode close call
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*/
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int
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vn_close(vp, flags, cred, p)
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register 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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error = VOP_CLOSE(vp, flags, cred, p);
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vrele(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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int *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, p);
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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, p);
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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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static int
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vn_read(fp, uio, cred)
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struct file *fp;
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struct uio *uio;
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struct ucred *cred;
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{
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struct vnode *vp = (struct vnode *)fp->f_data;
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struct proc *p = uio->uio_procp;
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int count, error;
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int flag, seq;
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VOP_LEASE(vp, p, cred, LEASE_READ);
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
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uio->uio_offset = fp->f_offset;
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count = uio->uio_resid;
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flag = 0;
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if (fp->f_flag & FNONBLOCK)
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flag |= IO_NDELAY;
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/*
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* Sequential read heuristic.
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* If we have been doing sequential input,
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* a rewind operation doesn't turn off
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* sequential input mode.
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*/
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if (((fp->f_offset == 0) && (fp->f_seqcount > 0)) ||
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(fp->f_offset == fp->f_nextread)) {
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int tmpseq = fp->f_seqcount;
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/*
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* XXX we assume that the filesystem block size is
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* the default. Not true, but still gives us a pretty
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* good indicator of how sequential the read operations
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* are.
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*/
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tmpseq += ((count + BKVASIZE - 1) / BKVASIZE);
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if (tmpseq >= CHAR_MAX)
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tmpseq = CHAR_MAX;
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fp->f_seqcount = tmpseq;
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flag |= (fp->f_seqcount << 16);
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} else {
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if (fp->f_seqcount > 1)
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fp->f_seqcount = 1;
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else
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fp->f_seqcount = 0;
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}
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error = VOP_READ(vp, uio, flag, cred);
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fp->f_offset += count - uio->uio_resid;
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fp->f_nextread = fp->f_offset;
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VOP_UNLOCK(vp, 0, p);
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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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static int
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vn_write(fp, uio, cred)
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struct file *fp;
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struct uio *uio;
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struct ucred *cred;
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{
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struct vnode *vp = (struct vnode *)fp->f_data;
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struct proc *p = uio->uio_procp;
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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 & O_FSYNC) ||
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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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VOP_LEASE(vp, p, cred, LEASE_WRITE);
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vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
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uio->uio_offset = fp->f_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 (ioflag & IO_APPEND)
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fp->f_offset = uio->uio_offset;
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else
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fp->f_offset += count - uio->uio_resid;
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VOP_UNLOCK(vp, 0, p);
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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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register struct stat *sb;
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struct proc *p;
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{
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struct vattr vattr;
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register struct vattr *vap;
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int error;
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u_short mode;
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vap = &vattr;
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error = VOP_GETATTR(vp, vap, 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 = vap->va_fsid;
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sb->st_ino = vap->va_fileid;
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mode = vap->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 = vap->va_nlink;
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sb->st_uid = vap->va_uid;
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sb->st_gid = vap->va_gid;
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sb->st_rdev = vap->va_rdev;
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sb->st_size = vap->va_size;
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sb->st_atimespec = vap->va_atime;
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sb->st_mtimespec = vap->va_mtime;
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sb->st_ctimespec = vap->va_ctime;
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sb->st_blksize = vap->va_blocksize;
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sb->st_flags = vap->va_flags;
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if (p->p_ucred->cr_uid != 0)
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sb->st_gen = 0;
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else
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sb->st_gen = vap->va_gen;
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#if (S_BLKSIZE == 512)
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/* Optimize this case */
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sb->st_blocks = vap->va_bytes >> 9;
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#else
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sb->st_blocks = vap->va_bytes / S_BLKSIZE;
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#endif
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return (0);
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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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static int
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vn_ioctl(fp, com, data, p)
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struct file *fp;
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int com;
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caddr_t data;
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struct proc *p;
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{
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register struct vnode *vp = ((struct vnode *)fp->f_data);
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struct vattr vattr;
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int error;
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switch (vp->v_type) {
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case VREG:
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case VDIR:
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if (com == FIONREAD) {
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error = VOP_GETATTR(vp, &vattr, p->p_ucred, p);
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if (error)
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return (error);
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*(int *)data = vattr.va_size - fp->f_offset;
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return (0);
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}
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if (com == FIONBIO || com == FIOASYNC) /* XXX */
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return (0); /* XXX */
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/* fall into ... */
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default:
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return (ENOTTY);
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case VFIFO:
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case VCHR:
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case VBLK:
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error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p);
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if (error == 0 && com == TIOCSCTTY) {
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/* Do nothing if reassigning same control tty */
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if (p->p_session->s_ttyvp == vp)
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return (0);
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/* Get rid of reference to old control tty */
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if (p->p_session->s_ttyvp)
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vrele(p->p_session->s_ttyvp);
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p->p_session->s_ttyvp = vp;
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VREF(vp);
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}
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return (error);
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}
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}
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/*
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* File table vnode select routine.
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*/
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static int
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vn_select(fp, which, p)
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struct file *fp;
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int which;
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struct proc *p;
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{
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return (VOP_SELECT(((struct vnode *)fp->f_data), which, fp->f_flag,
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fp->f_cred, p));
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}
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/*
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* File table vnode close routine.
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*/
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static int
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vn_closefile(fp, p)
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struct file *fp;
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struct proc *p;
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{
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return (vn_close(((struct vnode *)fp->f_data), fp->f_flag,
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fp->f_cred, p));
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}
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/*
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* Check that the vnode is still valid, and if so
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* acquire requested lock.
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*/
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int
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vn_lock(vp, flags, p)
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struct vnode *vp;
|
|
int flags;
|
|
struct proc *p;
|
|
{
|
|
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, p);
|
|
if (error == 0)
|
|
return (error);
|
|
}
|
|
flags &= ~LK_INTERLOCK;
|
|
} while (flags & LK_RETRY);
|
|
return (error);
|
|
}
|