375 lines
9.7 KiB
C
375 lines
9.7 KiB
C
/* $NetBSD: ext2fs_readwrite.c,v 1.24 2002/03/25 02:23:55 chs Exp $ */
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/*-
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* Copyright (c) 1997 Manuel Bouyer.
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* Copyright (c) 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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* @(#)ufs_readwrite.c 8.8 (Berkeley) 8/4/94
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* Modified for ext2fs by Manuel Bouyer.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: ext2fs_readwrite.c,v 1.24 2002/03/25 02:23:55 chs Exp $");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/resourcevar.h>
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#include <sys/kernel.h>
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#include <sys/file.h>
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#include <sys/stat.h>
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#include <sys/buf.h>
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#include <sys/proc.h>
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#include <sys/conf.h>
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#include <sys/mount.h>
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#include <sys/vnode.h>
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#include <sys/malloc.h>
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#include <sys/signalvar.h>
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#include <ufs/ufs/inode.h>
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#include <ufs/ext2fs/ext2fs.h>
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#include <ufs/ext2fs/ext2fs_extern.h>
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#define doclusterread 0 /* XXX underway */
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#define doclusterwrite 0
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/*
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* Vnode op for reading.
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*/
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/* ARGSUSED */
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int
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ext2fs_read(v)
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void *v;
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{
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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 = v;
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struct vnode *vp;
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struct inode *ip;
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struct uio *uio;
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struct m_ext2fs *fs;
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struct buf *bp;
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void *win;
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vsize_t bytelen;
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ufs_daddr_t lbn, nextlbn;
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off_t bytesinfile;
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long size, xfersize, blkoffset;
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int error;
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vp = ap->a_vp;
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ip = VTOI(vp);
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uio = ap->a_uio;
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#ifdef DIAGNOSTIC
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if (uio->uio_rw != UIO_READ)
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panic("%s: mode", "ext2fs_read");
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if (vp->v_type == VLNK) {
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if ((int)ip->i_e2fs_size < vp->v_mount->mnt_maxsymlinklen ||
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(vp->v_mount->mnt_maxsymlinklen == 0 &&
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ip->i_e2fs_nblock == 0))
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panic("%s: short symlink", "ext2fs_read");
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} else if (vp->v_type != VREG && vp->v_type != VDIR)
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panic("%s: type %d", "ext2fs_read", vp->v_type);
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#endif
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fs = ip->i_e2fs;
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if ((u_int64_t)uio->uio_offset >
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((u_int64_t)0x80000000 * fs->e2fs_bsize - 1))
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return (EFBIG);
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if (uio->uio_resid == 0)
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return (0);
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if (uio->uio_offset >= ip->i_e2fs_size)
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return (0);
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if (vp->v_type == VREG) {
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error = 0;
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while (uio->uio_resid > 0) {
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bytelen = MIN(ip->i_e2fs_size - uio->uio_offset,
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uio->uio_resid);
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if (bytelen == 0) {
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break;
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}
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win = ubc_alloc(&vp->v_uobj, uio->uio_offset,
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&bytelen, UBC_READ);
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error = uiomove(win, bytelen, uio);
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ubc_release(win, 0);
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if (error) {
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break;
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}
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}
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goto out;
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}
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for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
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if ((bytesinfile = ip->i_e2fs_size - uio->uio_offset) <= 0)
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break;
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lbn = lblkno(fs, uio->uio_offset);
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nextlbn = lbn + 1;
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size = fs->e2fs_bsize;
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blkoffset = blkoff(fs, uio->uio_offset);
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xfersize = fs->e2fs_bsize - blkoffset;
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if (uio->uio_resid < xfersize)
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xfersize = uio->uio_resid;
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if (bytesinfile < xfersize)
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xfersize = bytesinfile;
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if (lblktosize(fs, nextlbn) >= ip->i_e2fs_size)
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error = bread(vp, lbn, size, NOCRED, &bp);
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else {
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int nextsize = fs->e2fs_bsize;
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error = breadn(vp, lbn,
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size, &nextlbn, &nextsize, 1, NOCRED, &bp);
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}
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if (error)
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break;
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/*
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* We should only get non-zero b_resid when an I/O error
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* has occurred, which should cause us to break above.
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* However, if the short read did not cause an error,
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* then we want to ensure that we do not uiomove bad
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* or uninitialized data.
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*/
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size -= bp->b_resid;
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if (size < xfersize) {
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if (size == 0)
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break;
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xfersize = size;
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}
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error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio);
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if (error)
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break;
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brelse(bp);
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}
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if (bp != NULL)
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brelse(bp);
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out:
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if (!(vp->v_mount->mnt_flag & MNT_NOATIME)) {
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ip->i_flag |= IN_ACCESS;
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if ((ap->a_ioflag & IO_SYNC) == IO_SYNC)
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error = VOP_UPDATE(vp, NULL, NULL, UPDATE_WAIT);
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}
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return (error);
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}
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/*
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* Vnode op for writing.
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*/
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int
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ext2fs_write(v)
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void *v;
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{
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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 = v;
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struct vnode *vp;
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struct uio *uio;
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struct inode *ip;
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struct m_ext2fs *fs;
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struct buf *bp;
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struct proc *p;
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ufs_daddr_t lbn;
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off_t osize;
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int blkoffset, error, flags, ioflag, resid, xfersize;
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vsize_t bytelen;
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void *win;
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off_t oldoff;
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boolean_t async;
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ioflag = ap->a_ioflag;
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uio = ap->a_uio;
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vp = ap->a_vp;
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ip = VTOI(vp);
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error = 0;
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#ifdef DIAGNOSTIC
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if (uio->uio_rw != UIO_WRITE)
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panic("%s: mode", "ext2fs_write");
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#endif
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switch (vp->v_type) {
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case VREG:
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if (ioflag & IO_APPEND)
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uio->uio_offset = ip->i_e2fs_size;
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if ((ip->i_e2fs_flags & EXT2_APPEND) &&
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uio->uio_offset != ip->i_e2fs_size)
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return (EPERM);
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/* FALLTHROUGH */
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case VLNK:
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break;
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case VDIR:
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if ((ioflag & IO_SYNC) == 0)
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panic("%s: nonsync dir write", "ext2fs_write");
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break;
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default:
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panic("%s: type", "ext2fs_write");
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}
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fs = ip->i_e2fs;
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if (uio->uio_offset < 0 ||
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(u_int64_t)uio->uio_offset + uio->uio_resid >
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((u_int64_t)0x80000000 * fs->e2fs_bsize - 1))
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return (EFBIG);
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/*
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* Maybe this should be above the vnode op call, but so long as
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* file servers have no limits, I don't think it matters.
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*/
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p = uio->uio_procp;
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if (vp->v_type == VREG && p &&
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uio->uio_offset + uio->uio_resid >
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p->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
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psignal(p, SIGXFSZ);
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return (EFBIG);
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}
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if (uio->uio_resid == 0)
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return (0);
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async = vp->v_mount->mnt_flag & MNT_ASYNC;
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resid = uio->uio_resid;
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osize = ip->i_e2fs_size;
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if (vp->v_type == VREG) {
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while (uio->uio_resid > 0) {
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oldoff = uio->uio_offset;
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blkoffset = blkoff(fs, uio->uio_offset);
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bytelen = MIN(fs->e2fs_bsize - blkoffset,
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uio->uio_resid);
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error = ext2fs_balloc_range(vp, uio->uio_offset,
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bytelen, ap->a_cred, 0);
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if (error) {
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break;
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}
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win = ubc_alloc(&vp->v_uobj, uio->uio_offset,
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&bytelen, UBC_WRITE);
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error = uiomove(win, bytelen, uio);
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ubc_release(win, 0);
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if (error) {
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break;
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}
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/*
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* update UVM's notion of the size now that we've
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* copied the data into the vnode's pages.
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*/
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if (vp->v_size < uio->uio_offset) {
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uvm_vnp_setsize(vp, uio->uio_offset);
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}
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/*
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* flush what we just wrote if necessary.
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* XXXUBC simplistic async flushing.
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*/
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if (!async && oldoff >> 16 != uio->uio_offset >> 16) {
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simple_lock(&vp->v_interlock);
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error = VOP_PUTPAGES(vp, (oldoff >> 16) << 16,
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(uio->uio_offset >> 16) << 16, PGO_CLEANIT);
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}
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}
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if (error == 0 && ioflag & IO_SYNC) {
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simple_lock(&vp->v_interlock);
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error = VOP_PUTPAGES(vp, trunc_page(oldoff),
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round_page(blkroundup(fs, uio->uio_offset)),
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PGO_CLEANIT | PGO_SYNCIO);
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}
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goto out;
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}
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flags = ioflag & IO_SYNC ? B_SYNC : 0;
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for (error = 0; uio->uio_resid > 0;) {
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lbn = lblkno(fs, uio->uio_offset);
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blkoffset = blkoff(fs, uio->uio_offset);
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xfersize = MIN(fs->e2fs_bsize - blkoffset, uio->uio_resid);
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if (xfersize < fs->e2fs_bsize)
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flags |= B_CLRBUF;
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else
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flags &= ~B_CLRBUF;
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error = ext2fs_balloc(ip,
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lbn, blkoffset + xfersize, ap->a_cred, &bp, flags);
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if (error)
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break;
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if (ip->i_e2fs_size < uio->uio_offset + xfersize) {
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ip->i_e2fs_size = uio->uio_offset + xfersize;
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}
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error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio);
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/*
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* update UVM's notion of the size now that we've
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* copied the data into the vnode's pages.
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*/
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if (vp->v_size < uio->uio_offset) {
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uvm_vnp_setsize(vp, uio->uio_offset);
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}
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if (ioflag & IO_SYNC)
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(void)bwrite(bp);
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else if (xfersize + blkoffset == fs->e2fs_bsize)
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bawrite(bp);
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else
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bdwrite(bp);
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if (error || xfersize == 0)
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break;
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}
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/*
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* If we successfully wrote any data, and we are not the superuser
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* we clear the setuid and setgid bits as a precaution against
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* tampering.
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*/
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out:
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ip->i_flag |= IN_CHANGE | IN_UPDATE;
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if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0)
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ip->i_e2fs_mode &= ~(ISUID | ISGID);
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if (error) {
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(void) VOP_TRUNCATE(vp, osize, ioflag & IO_SYNC, ap->a_cred,
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uio->uio_procp);
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uio->uio_offset -= resid - uio->uio_resid;
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uio->uio_resid = resid;
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} else if (resid > uio->uio_resid && (ioflag & IO_SYNC) == IO_SYNC)
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error = VOP_UPDATE(vp, NULL, NULL, UPDATE_WAIT);
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KASSERT(vp->v_size == ip->i_e2fs_size);
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return (error);
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}
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