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15a1057c46
lock, and add some macros and function parameters to make sure that the information get to the point where it can be put in the lock structure. While I'm here, add DEBUG_VFS_LOCKS to LINT.
563 lines
13 KiB
C
563 lines
13 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 1.61 1999/01/05 18:49:56 eivind 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/fcntl.h>
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#include <sys/file.h>
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#include <sys/stat.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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static int vn_closefile __P((struct file *fp, struct proc *p));
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static int vn_ioctl __P((struct file *fp, u_long 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_poll __P((struct file *fp, int events, struct ucred *cred,
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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_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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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 mode, 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 && (fmode & O_NOFOLLOW) == 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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error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
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&ndp->ni_cnd, vap);
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vput(ndp->ni_dvp);
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if (error)
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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 =
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((fmode & O_NOFOLLOW) ? NOFOLLOW : 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 == VLNK) {
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error = EMLINK;
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goto bad;
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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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mode = 0;
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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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mode |= VWRITE;
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}
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if (fmode & FREAD)
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mode |= VREAD;
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if (mode) {
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error = VOP_ACCESS(vp, mode, 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)) != 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;
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VOP_LEASE(vp, p, cred, LEASE_READ);
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vn_lock(vp, LK_SHARED | LK_NOPAUSE | LK_RETRY, p);
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if (uio->uio_offset == -1)
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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 >= 127)
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tmpseq = 127;
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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 (uio->uio_offset == -1 && 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 (vap->va_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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/* This is a cosmetic change, symlinks do not have a mode. */
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if (vp->v_mount->mnt_flag & MNT_NOSYMFOLLOW)
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sb->st_mode &= ~ACCESSPERMS; /* 0000 */
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else
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sb->st_mode |= ACCESSPERMS; /* 0777 */
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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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u_long 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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#if 0
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return (ENOTTY);
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#endif
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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 poll routine.
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*/
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static int
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vn_poll(fp, events, cred, p)
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struct file *fp;
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int events;
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struct ucred *cred;
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struct proc *p;
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{
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|
|
return (VOP_POLL(((struct vnode *)fp->f_data), events, cred, p));
|
|
}
|
|
|
|
/*
|
|
* Check that the vnode is still valid, and if so
|
|
* acquire requested lock.
|
|
*/
|
|
int
|
|
#ifndef DEBUG_LOCKS
|
|
vn_lock(vp, flags, p)
|
|
#else
|
|
debug_vn_lock(vp, flags, p, filename, line)
|
|
#endif
|
|
struct vnode *vp;
|
|
int flags;
|
|
struct proc *p;
|
|
#ifdef DEBUG_LOCKS
|
|
const char *filename;
|
|
int line;
|
|
#endif
|
|
{
|
|
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 {
|
|
#ifdef DEBUG_LOCKS
|
|
vp->filename = filename;
|
|
vp->line = line;
|
|
#endif
|
|
error = VOP_LOCK(vp,
|
|
flags | LK_NOPAUSE | LK_INTERLOCK, p);
|
|
if (error == 0)
|
|
return (error);
|
|
}
|
|
flags &= ~LK_INTERLOCK;
|
|
} while (flags & LK_RETRY);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* File table vnode close routine.
|
|
*/
|
|
static 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));
|
|
}
|