538 lines
13 KiB
C
538 lines
13 KiB
C
/* $NetBSD: vn.c,v 1.15 1994/12/14 19:09:15 mycroft Exp $ */
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/*
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* Copyright (c) 1988 University of Utah.
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* Copyright (c) 1990, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* the Systems Programming Group of the University of Utah Computer
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* Science Department.
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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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* from: Utah $Hdr: vn.c 1.13 94/04/02$
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*
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* @(#)vn.c 8.6 (Berkeley) 4/1/94
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*/
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/*
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* Vnode disk driver.
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*
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* Block/character interface to a vnode. Allows one to treat a file
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* as a disk (e.g. build a filesystem in it, mount it, etc.).
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*
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* NOTE 1: This uses the VOP_BMAP/VOP_STRATEGY interface to the vnode
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* instead of a simple VOP_RDWR. We do this to avoid distorting the
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* local buffer cache.
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*
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* NOTE 2: There is a security issue involved with this driver.
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* Once mounted all access to the contents of the "mapped" file via
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* the special file is controlled by the permissions on the special
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* file, the protection of the mapped file is ignored (effectively,
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* by using root credentials in all transactions).
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*
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* NOTE 3: Doesn't interact with leases, should it?
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*/
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#include "vn.h"
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#if NVN > 0
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/namei.h>
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#include <sys/proc.h>
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#include <sys/errno.h>
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#include <sys/dkstat.h>
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#include <sys/buf.h>
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#include <sys/malloc.h>
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#include <sys/ioctl.h>
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#include <sys/mount.h>
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#include <sys/vnode.h>
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#include <sys/file.h>
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#include <sys/uio.h>
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#include <miscfs/specfs/specdev.h>
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#include <dev/vnioctl.h>
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#ifdef DEBUG
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int dovncluster = 1;
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int vndebug = 0x00;
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#define VDB_FOLLOW 0x01
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#define VDB_INIT 0x02
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#define VDB_IO 0x04
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#endif
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#define b_cylin b_resid
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#define vnunit(x) ((minor(x) >> 3) & 0x7) /* for consistency */
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#define getvnbuf() \
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((struct buf *)malloc(sizeof(struct buf), M_DEVBUF, M_WAITOK))
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#define putvnbuf(bp) \
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free((caddr_t)(bp), M_DEVBUF)
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struct vn_softc {
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int sc_flags; /* flags */
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size_t sc_size; /* size of vn */
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struct vnode *sc_vp; /* vnode */
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struct ucred *sc_cred; /* credentials */
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int sc_maxactive; /* max # of active requests */
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struct buf sc_tab; /* transfer queue */
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};
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/* sc_flags */
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#define VNF_ALIVE 0x01
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#define VNF_INITED 0x02
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#if 0 /* if you need static allocation */
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struct vn_softc vn_softc[NVN];
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int numvnd = NVN;
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#else
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struct vn_softc *vn_softc;
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int numvnd;
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#endif
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void
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vnattach(num)
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int num;
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{
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char *mem;
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register u_long size;
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if (num <= 0)
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return;
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size = num * sizeof(struct vn_softc);
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mem = malloc(size, M_DEVBUF, M_NOWAIT);
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if (mem == NULL) {
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printf("WARNING: no memory for vnode disks\n");
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return;
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}
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bzero(mem, size);
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vn_softc = (struct vn_softc *)mem;
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numvnd = num;
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}
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int
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vnopen(dev, flags, mode, p)
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dev_t dev;
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int flags, mode;
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struct proc *p;
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{
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int unit = vnunit(dev);
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#ifdef DEBUG
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if (vndebug & VDB_FOLLOW)
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printf("vnopen(%x, %x, %x, %x)\n", dev, flags, mode, p);
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#endif
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if (unit >= numvnd)
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return(ENXIO);
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return(0);
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}
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int
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vnclose(dev, flags, mode, p)
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dev_t dev;
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int flags, mode;
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struct proc *p;
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{
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#ifdef DEBUG
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if (vndebug & VDB_FOLLOW)
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printf("vnclose(%x, %x, %x, %x)\n", dev, flags, mode, p);
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#endif
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return 0;
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}
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/*
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* Break the request into bsize pieces and submit using VOP_BMAP/VOP_STRATEGY.
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* Note that this driver can only be used for swapping over NFS on the hp
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* since nfs_strategy on the vax cannot handle u-areas and page tables.
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*/
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void
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vnstrategy(bp)
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register struct buf *bp;
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{
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int unit = vnunit(bp->b_dev);
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register struct vn_softc *vn = &vn_softc[unit];
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register struct buf *nbp;
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register int bn, bsize, resid;
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register caddr_t addr;
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int sz, flags, error;
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extern void vniodone();
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#ifdef DEBUG
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if (vndebug & VDB_FOLLOW)
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printf("vnstrategy(%x): unit %d\n", bp, unit);
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#endif
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if ((vn->sc_flags & VNF_INITED) == 0) {
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bp->b_error = ENXIO;
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bp->b_flags |= B_ERROR;
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biodone(bp);
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return;
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}
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bn = bp->b_blkno;
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sz = howmany(bp->b_bcount, DEV_BSIZE);
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bp->b_resid = bp->b_bcount;
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if (bn < 0 || bn + sz > vn->sc_size) {
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if (bn != vn->sc_size) {
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bp->b_error = EINVAL;
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bp->b_flags |= B_ERROR;
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}
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biodone(bp);
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return;
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}
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bn = dbtob(bn);
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bsize = vn->sc_vp->v_mount->mnt_stat.f_iosize;
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addr = bp->b_data;
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flags = bp->b_flags | B_CALL;
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for (resid = bp->b_resid; resid; resid -= sz) {
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struct vnode *vp;
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daddr_t nbn;
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int off, s, nra;
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nra = 0;
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error = VOP_BMAP(vn->sc_vp, bn / bsize, &vp, &nbn, &nra);
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if (error == 0 && (long)nbn == -1)
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error = EIO;
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#ifdef DEBUG
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if (!dovncluster)
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nra = 0;
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#endif
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if (off = bn % bsize)
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sz = bsize - off;
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else
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sz = (1 + nra) * bsize;
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if (resid < sz)
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sz = resid;
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#ifdef DEBUG
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if (vndebug & VDB_IO)
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printf("vnstrategy: vp %x/%x bn %x/%x sz %x\n",
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vn->sc_vp, vp, bn, nbn, sz);
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#endif
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nbp = getvnbuf();
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nbp->b_flags = flags;
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nbp->b_bcount = sz;
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nbp->b_bufsize = bp->b_bufsize;
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nbp->b_error = 0;
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if (vp->v_type == VBLK || vp->v_type == VCHR)
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nbp->b_dev = vp->v_rdev;
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else
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nbp->b_dev = NODEV;
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nbp->b_data = addr;
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nbp->b_blkno = nbn + btodb(off);
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nbp->b_proc = bp->b_proc;
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nbp->b_iodone = vniodone;
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nbp->b_vp = vp;
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nbp->b_pfcent = (int) bp; /* XXX */
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nbp->b_rcred = vn->sc_cred; /* XXX crdup? */
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nbp->b_wcred = vn->sc_cred; /* XXX crdup? */
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nbp->b_dirtyoff = bp->b_dirtyoff;
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nbp->b_dirtyend = bp->b_dirtyend;
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nbp->b_validoff = bp->b_validoff;
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nbp->b_validend = bp->b_validend;
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/*
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* If there was an error or a hole in the file...punt.
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* Note that we deal with this after the nbp allocation.
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* This ensures that we properly clean up any operations
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* that we have already fired off.
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*
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* XXX we could deal with holes here but it would be
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* a hassle (in the write case).
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*/
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if (error) {
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nbp->b_error = error;
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nbp->b_flags |= B_ERROR;
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bp->b_resid -= (resid - sz);
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biodone(nbp);
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return;
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}
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/*
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* Just sort by block number
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*/
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nbp->b_cylin = nbp->b_blkno;
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s = splbio();
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disksort(&vn->sc_tab, nbp);
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if (vn->sc_tab.b_active < vn->sc_maxactive) {
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vn->sc_tab.b_active++;
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vnstart(vn);
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}
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splx(s);
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bn += sz;
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addr += sz;
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}
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}
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/*
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* Feed requests sequentially.
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* We do it this way to keep from flooding NFS servers if we are connected
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* to an NFS file. This places the burden on the client rather than the
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* server.
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*/
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vnstart(vn)
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register struct vn_softc *vn;
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{
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register struct buf *bp;
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/*
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* Dequeue now since lower level strategy routine might
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* queue using same links
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*/
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bp = vn->sc_tab.b_actf;
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vn->sc_tab.b_actf = bp->b_actf;
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#ifdef DEBUG
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if (vndebug & VDB_IO)
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printf("vnstart(%d): bp %x vp %x blkno %x addr %x cnt %x\n",
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vn-vn_softc, bp, bp->b_vp, bp->b_blkno, bp->b_data,
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bp->b_bcount);
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#endif
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if ((bp->b_flags & B_READ) == 0)
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bp->b_vp->v_numoutput++;
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VOP_STRATEGY(bp);
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}
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void
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vniodone(bp)
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register struct buf *bp;
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{
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register struct buf *pbp = (struct buf *)bp->b_pfcent; /* XXX */
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register struct vn_softc *vn = &vn_softc[vnunit(pbp->b_dev)];
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int s;
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s = splbio();
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#ifdef DEBUG
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if (vndebug & VDB_IO)
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printf("vniodone(%d): bp %x vp %x blkno %x addr %x cnt %x\n",
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vn-vn_softc, bp, bp->b_vp, bp->b_blkno, bp->b_data,
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bp->b_bcount);
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#endif
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if (bp->b_error) {
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#ifdef DEBUG
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if (vndebug & VDB_IO)
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printf("vniodone: bp %x error %d\n", bp, bp->b_error);
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#endif
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pbp->b_flags |= B_ERROR;
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pbp->b_error = biowait(bp);
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}
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pbp->b_resid -= bp->b_bcount;
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putvnbuf(bp);
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if (pbp->b_resid == 0) {
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#ifdef DEBUG
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if (vndebug & VDB_IO)
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printf("vniodone: pbp %x iodone\n", pbp);
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#endif
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biodone(pbp);
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}
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if (vn->sc_tab.b_actf)
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vnstart(vn);
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else
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vn->sc_tab.b_active--;
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splx(s);
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}
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/* ARGSUSED */
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vnioctl(dev, cmd, data, flag, p)
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dev_t dev;
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u_long cmd;
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caddr_t data;
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int flag;
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struct proc *p;
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{
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int unit = vnunit(dev);
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register struct vn_softc *vn;
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struct vn_ioctl *vio;
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struct vattr vattr;
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struct nameidata nd;
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int error;
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#ifdef DEBUG
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if (vndebug & VDB_FOLLOW)
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printf("vnioctl(%x, %lx, %x, %x, %x): unit %d\n",
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dev, cmd, data, flag, p, unit);
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#endif
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error = suser(p->p_ucred, &p->p_acflag);
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if (error)
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return (error);
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if (unit >= numvnd)
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return (ENXIO);
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vn = &vn_softc[unit];
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vio = (struct vn_ioctl *)data;
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switch (cmd) {
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case VNIOCSET:
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if (vn->sc_flags & VNF_INITED)
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return(EBUSY);
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/*
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* Always open for read and write.
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* This is probably bogus, but it lets vn_open()
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* weed out directories, sockets, etc. so we don't
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* have to worry about them.
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*/
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NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, vio->vn_file, p);
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if (error = vn_open(&nd, FREAD|FWRITE, 0))
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return(error);
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if (error = VOP_GETATTR(nd.ni_vp, &vattr, p->p_ucred, p)) {
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VOP_UNLOCK(nd.ni_vp);
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(void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p);
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return(error);
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}
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VOP_UNLOCK(nd.ni_vp);
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vn->sc_vp = nd.ni_vp;
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vn->sc_size = btodb(vattr.va_size); /* note truncation */
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if (error = vnsetcred(vn, p->p_ucred)) {
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(void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p);
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return(error);
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}
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vnthrottle(vn, vn->sc_vp);
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vio->vn_size = dbtob(vn->sc_size);
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vn->sc_flags |= VNF_INITED;
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#ifdef DEBUG
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if (vndebug & VDB_INIT)
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printf("vnioctl: SET vp %x size %x\n",
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vn->sc_vp, vn->sc_size);
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#endif
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break;
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case VNIOCCLR:
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if ((vn->sc_flags & VNF_INITED) == 0)
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return(ENXIO);
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vnclear(vn);
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#ifdef DEBUG
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if (vndebug & VDB_INIT)
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printf("vnioctl: CLRed\n");
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#endif
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break;
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default:
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return(ENOTTY);
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}
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return(0);
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}
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/*
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* Duplicate the current processes' credentials. Since we are called only
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* as the result of a SET ioctl and only root can do that, any future access
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* to this "disk" is essentially as root. Note that credentials may change
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* if some other uid can write directly to the mapped file (NFS).
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*/
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vnsetcred(vn, cred)
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register struct vn_softc *vn;
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struct ucred *cred;
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{
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struct uio auio;
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struct iovec aiov;
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char *tmpbuf;
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int error;
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vn->sc_cred = crdup(cred);
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tmpbuf = malloc(DEV_BSIZE, M_TEMP, M_WAITOK);
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/* XXX: Horrible kludge to establish credentials for NFS */
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aiov.iov_base = tmpbuf;
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aiov.iov_len = min(DEV_BSIZE, dbtob(vn->sc_size));
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auio.uio_iov = &aiov;
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auio.uio_iovcnt = 1;
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auio.uio_offset = 0;
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auio.uio_rw = UIO_READ;
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auio.uio_segflg = UIO_SYSSPACE;
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auio.uio_resid = aiov.iov_len;
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error = VOP_READ(vn->sc_vp, &auio, 0, vn->sc_cred);
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free(tmpbuf, M_TEMP);
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return (error);
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}
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/*
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* Set maxactive based on FS type
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*/
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vnthrottle(vn, vp)
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register struct vn_softc *vn;
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struct vnode *vp;
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{
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#ifdef NFSCLIENT
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extern int (**nfsv2_vnodeop_p)();
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if (vp->v_op == nfsv2_vnodeop_p)
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vn->sc_maxactive = 2;
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else
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#endif
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vn->sc_maxactive = 8;
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if (vn->sc_maxactive < 1)
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vn->sc_maxactive = 1;
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}
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vnshutdown()
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{
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register struct vn_softc *vn;
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for (vn = &vn_softc[0]; vn < &vn_softc[numvnd]; vn++)
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if (vn->sc_flags & VNF_INITED)
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vnclear(vn);
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}
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vnclear(vn)
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register struct vn_softc *vn;
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{
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register struct vnode *vp = vn->sc_vp;
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struct proc *p = curproc; /* XXX */
|
|
|
|
#ifdef DEBUG
|
|
if (vndebug & VDB_FOLLOW)
|
|
printf("vnclear(%x): vp %x\n", vp);
|
|
#endif
|
|
vn->sc_flags &= ~VNF_INITED;
|
|
if (vp == (struct vnode *)0)
|
|
panic("vnioctl: null vp");
|
|
(void) vn_close(vp, FREAD|FWRITE, vn->sc_cred, p);
|
|
crfree(vn->sc_cred);
|
|
vn->sc_vp = (struct vnode *)0;
|
|
vn->sc_cred = (struct ucred *)0;
|
|
vn->sc_size = 0;
|
|
}
|
|
|
|
vnsize(dev)
|
|
dev_t dev;
|
|
{
|
|
int unit = vnunit(dev);
|
|
register struct vn_softc *vn = &vn_softc[unit];
|
|
|
|
if (unit >= numvnd || (vn->sc_flags & VNF_INITED) == 0)
|
|
return(-1);
|
|
return(vn->sc_size);
|
|
}
|
|
|
|
vndump(dev)
|
|
{
|
|
return(ENXIO);
|
|
}
|
|
#endif
|