270 lines
6.8 KiB
C
270 lines
6.8 KiB
C
/*
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* Copyright (c) 1989, 1993
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* The Regents of the University of California. All rights reserved.
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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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* @(#)dead_vnops.c 8.1 (Berkeley) 6/10/93
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* $FreeBSD$
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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/lock.h>
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#include <sys/mutex.h>
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#include <sys/poll.h>
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#include <sys/vnode.h>
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static int chkvnlock(struct vnode *);
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/*
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* Prototypes for dead operations on vnodes.
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*/
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static int dead_bmap(struct vop_bmap_args *);
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static int dead_ioctl(struct vop_ioctl_args *);
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static int dead_lock(struct vop_lock_args *);
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static int dead_lookup(struct vop_lookup_args *);
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static int dead_open(struct vop_open_args *);
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static int dead_poll(struct vop_poll_args *);
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static int dead_read(struct vop_read_args *);
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static int dead_write(struct vop_write_args *);
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vop_t **dead_vnodeop_p;
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static struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
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{ &vop_default_desc, (vop_t *) vop_defaultop },
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{ &vop_access_desc, (vop_t *) vop_ebadf },
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{ &vop_advlock_desc, (vop_t *) vop_ebadf },
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{ &vop_bmap_desc, (vop_t *) dead_bmap },
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{ &vop_create_desc, (vop_t *) vop_panic },
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{ &vop_getattr_desc, (vop_t *) vop_ebadf },
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{ &vop_inactive_desc, (vop_t *) vop_null },
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{ &vop_ioctl_desc, (vop_t *) dead_ioctl },
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{ &vop_link_desc, (vop_t *) vop_panic },
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{ &vop_lock_desc, (vop_t *) dead_lock },
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{ &vop_lookup_desc, (vop_t *) dead_lookup },
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{ &vop_mkdir_desc, (vop_t *) vop_panic },
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{ &vop_mknod_desc, (vop_t *) vop_panic },
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{ &vop_open_desc, (vop_t *) dead_open },
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{ &vop_pathconf_desc, (vop_t *) vop_ebadf }, /* per pathconf(2) */
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{ &vop_poll_desc, (vop_t *) dead_poll },
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{ &vop_print_desc, (vop_t *) vop_null },
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{ &vop_read_desc, (vop_t *) dead_read },
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{ &vop_readdir_desc, (vop_t *) vop_ebadf },
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{ &vop_readlink_desc, (vop_t *) vop_ebadf },
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{ &vop_reclaim_desc, (vop_t *) vop_null },
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{ &vop_remove_desc, (vop_t *) vop_panic },
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{ &vop_rename_desc, (vop_t *) vop_panic },
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{ &vop_rmdir_desc, (vop_t *) vop_panic },
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{ &vop_setattr_desc, (vop_t *) vop_ebadf },
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{ &vop_symlink_desc, (vop_t *) vop_panic },
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{ &vop_write_desc, (vop_t *) dead_write },
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{ NULL, NULL }
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};
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static struct vnodeopv_desc dead_vnodeop_opv_desc =
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{ &dead_vnodeop_p, dead_vnodeop_entries };
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VNODEOP_SET(dead_vnodeop_opv_desc);
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/*
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* Trivial lookup routine that always fails.
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*/
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/* ARGSUSED */
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static int
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dead_lookup(ap)
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struct vop_lookup_args /* {
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struct vnode * a_dvp;
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struct vnode ** a_vpp;
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struct componentname * a_cnp;
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} */ *ap;
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{
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*ap->a_vpp = NULL;
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return (ENOTDIR);
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}
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/*
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* Open always fails as if device did not exist.
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*/
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/* ARGSUSED */
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static int
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dead_open(ap)
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struct vop_open_args /* {
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struct vnode *a_vp;
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int a_mode;
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struct ucred *a_cred;
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struct proc *a_p;
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} */ *ap;
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{
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return (ENXIO);
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}
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/*
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* Vnode op for read
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*/
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/* ARGSUSED */
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static int
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dead_read(ap)
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struct vop_read_args /* {
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struct vnode *a_vp;
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struct uio *a_uio;
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int a_ioflag;
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struct ucred *a_cred;
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} */ *ap;
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{
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if (chkvnlock(ap->a_vp))
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panic("dead_read: lock");
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/*
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* Return EOF for tty devices, EIO for others
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*/
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if ((ap->a_vp->v_vflag & VV_ISTTY) == 0)
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return (EIO);
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return (0);
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}
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/*
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* Vnode op for write
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*/
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/* ARGSUSED */
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static int
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dead_write(ap)
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struct vop_write_args /* {
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struct vnode *a_vp;
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struct uio *a_uio;
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int a_ioflag;
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struct ucred *a_cred;
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} */ *ap;
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{
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if (chkvnlock(ap->a_vp))
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panic("dead_write: lock");
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return (EIO);
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}
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/*
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* Device ioctl operation.
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*/
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/* ARGSUSED */
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static int
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dead_ioctl(ap)
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struct vop_ioctl_args /* {
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struct vnode *a_vp;
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int a_command;
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caddr_t a_data;
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int a_fflag;
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struct ucred *a_cred;
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struct proc *a_p;
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} */ *ap;
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{
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if (!chkvnlock(ap->a_vp))
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return (ENOTTY);
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return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap));
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}
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/*
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* Wait until the vnode has finished changing state.
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*/
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static int
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dead_lock(ap)
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struct vop_lock_args /* {
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struct vnode *a_vp;
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int a_flags;
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struct proc *a_p;
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} */ *ap;
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{
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struct vnode *vp = ap->a_vp;
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/*
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* Since we are not using the lock manager, we must clear
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* the interlock here.
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*/
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if (ap->a_flags & LK_INTERLOCK) {
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mtx_unlock(&vp->v_interlock);
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ap->a_flags &= ~LK_INTERLOCK;
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}
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if (!chkvnlock(vp))
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return (0);
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return (VCALL(vp, VOFFSET(vop_lock), ap));
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}
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/*
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* Wait until the vnode has finished changing state.
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*/
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static int
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dead_bmap(ap)
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struct vop_bmap_args /* {
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struct vnode *a_vp;
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daddr_t a_bn;
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struct vnode **a_vpp;
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daddr_t *a_bnp;
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int *a_runp;
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int *a_runb;
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} */ *ap;
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{
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if (!chkvnlock(ap->a_vp))
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return (EIO);
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return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp, ap->a_runb));
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}
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/*
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* We have to wait during times when the vnode is
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* in a state of change.
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*/
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int
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chkvnlock(vp)
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register struct vnode *vp;
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{
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int locked = 0;
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VI_LOCK(vp);
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while (vp->v_iflag & VI_XLOCK) {
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vp->v_iflag |= VI_XWANT;
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(void) msleep((caddr_t)vp, VI_MTX(vp), PINOD, "ckvnlk", 0);
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locked = 1;
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}
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VI_UNLOCK(vp);
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return (locked);
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}
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/*
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* Trivial poll routine that always returns POLLHUP.
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* This is necessary so that a process which is polling a file
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* gets notified when that file is revoke()d.
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*/
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static int
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dead_poll(ap)
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struct vop_poll_args *ap;
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{
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return (POLLHUP);
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}
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