sys/vfs/gnu/ext2fs/ext2_subr.c

   1 /*
   2  *  modified for Lites 1.1
   3  *
   4  *  Aug 1995, Godmar Back (gback@cs.utah.edu)
   5  *  University of Utah, Department of Computer Science
   6  */
   7 /*
   8  * Copyright (c) 1982, 1986, 1989, 1993
   9  *      The Regents of the University of California.  All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. All advertising materials mentioning features or use of this software
  20  *    must display the following acknowledgement:
  21  *      This product includes software developed by the University of
  22  *      California, Berkeley and its contributors.
  23  * 4. Neither the name of the University nor the names of its contributors
  24  *    may be used to endorse or promote products derived from this software
  25  *    without specific prior written permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  37  * SUCH DAMAGE.
  38  *
  39  *      @(#)ext2_subr.c 8.2 (Berkeley) 9/21/93
  40  * $FreeBSD: src/sys/gnu/ext2fs/ext2_subr.c,v 1.13.2.2 2000/08/03 18:48:27 peter Exp $
  41  * $DragonFly: src/sys/vfs/gnu/ext2fs/ext2_subr.c,v 1.12 2006/04/27 23:28:36 dillon Exp $
  42  */
  43
  44 #include <sys/param.h>
  45
  46 #include <sys/lock.h>
  47 #include <sys/systm.h>
  48 #include <sys/ucred.h>
  49 #include <sys/vnode.h>
  50 #include <sys/buf.h>
  51
  52 #include "quota.h"
  53 #include "inode.h"
  54 #include "ext2_extern.h"
  55 #include "ext2_fs_sb.h"
  56 #include "fs.h"
  57
  58 #include "opt_ddb.h"
  59
  60 /*
  61  * Return buffer with the contents of block "offset" from the beginning of
  62  * directory "ip".  If "res" is non-zero, fill it in with a pointer to the
  63  * remaining space in the directory.
  64  */
  65 int
  66 ext2_blkatoff(struct vnode *vp, off_t offset, char **res, struct buf **bpp)
  67 {
  68         struct inode *ip;
  69         struct ext2_sb_info *fs;
  70         struct buf *bp;
  71         daddr_t lbn;
  72         int bsize, error;
  73
  74         ip = VTOI(vp);
  75         fs = ip->i_e2fs;
  76         lbn = lblkno(fs, offset);
  77         bsize = blksize(fs, ip, lbn);
  78
  79         *bpp = NULL;
  80         if ((error = bread(vp, lblktodoff(fs, lbn), bsize, &bp)) != 0) {
  81                 brelse(bp);
  82                 return (error);
  83         }
  84         if (res)
  85                 *res = (char *)bp->b_data + blkoff(fs, offset);
  86         *bpp = bp;
  87         return (0);
  88 }
  89