freebsd-dev/sys/gnu/ext2fs/ext2_subr.c

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/*
* modified for Lites 1.1
*
* Aug 1995, Godmar Back (gback@cs.utah.edu)
* University of Utah, Department of Computer Science
*/
/*
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)ffs_subr.c 8.2 (Berkeley) 9/21/93
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/lock.h>
#include <sys/ucred.h>
#include <sys/vnode.h>
#include <gnu/ext2fs/inode.h>
#include <gnu/ext2fs/ext2_extern.h>
#include <gnu/ext2fs/ext2_fs_sb.h>
#include <gnu/ext2fs/fs.h>
#include "opt_ddb.h"
#ifdef DDB
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void ext2_checkoverlap(struct buf *, struct inode *);
#endif
/*
* Return buffer with the contents of block "offset" from the beginning of
* directory "ip". If "res" is non-zero, fill it in with a pointer to the
* remaining space in the directory.
*/
int
ext2_blkatoff(vp, offset, res, bpp)
struct vnode *vp;
off_t offset;
char **res;
struct buf **bpp;
{
struct inode *ip;
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struct ext2_sb_info *fs;
struct buf *bp;
int32_t lbn;
int bsize, error;
ip = VTOI(vp);
fs = ip->i_e2fs;
lbn = lblkno(fs, offset);
bsize = blksize(fs, ip, lbn);
*bpp = NULL;
if ((error = bread(vp, lbn, bsize, NOCRED, &bp)) != 0) {
brelse(bp);
return (error);
}
if (res)
*res = (char *)bp->b_data + blkoff(fs, offset);
*bpp = bp;
return (0);
}
#ifdef DDB
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void
ext2_checkoverlap(bp, ip)
struct buf *bp;
struct inode *ip;
{
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struct buf *ebp, *ep;
int32_t start, last;
struct vnode *vp;
ebp = &buf[nbuf];
start = bp->b_blkno;
last = start + btodb(bp->b_bcount) - 1;
for (ep = buf; ep < ebp; ep++) {
if (ep == bp || (ep->b_flags & B_INVAL) ||
ep->b_vp == NULLVP)
continue;
vp = ip->i_devvp;
/* look for overlap */
if (ep->b_bcount == 0 || ep->b_blkno > last ||
ep->b_blkno + btodb(ep->b_bcount) <= start)
continue;
vprint("Disk overlap", vp);
(void)printf("\tstart %d, end %d overlap start %lld, end %ld\n",
start, last, (long long)ep->b_blkno,
(long)(ep->b_blkno + btodb(ep->b_bcount) - 1));
panic("Disk buffer overlap");
}
}
#endif /* DDB */