LXR linux/fs/gfs2/bmap.h

   1/*
   2 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
   4 *
   5 * This copyrighted material is made available to anyone wishing to use,
   6 * modify, copy, or redistribute it subject to the terms and conditions
   7 * of the GNU General Public License version 2.
   8 */
   9
  10#ifndef __BMAP_DOT_H__
  11#define __BMAP_DOT_H__
  12
  13#include "inode.h"
  14
  15struct inode;
  16struct gfs2_inode;
  17struct page;
  18
  19
  20/**
  21 * gfs2_write_calc_reserv - calculate number of blocks needed to write to a file
  22 * @ip: the file
  23 * @len: the number of bytes to be written to the file
  24 * @data_blocks: returns the number of data blocks required
  25 * @ind_blocks: returns the number of indirect blocks required
  26 *
  27 */
  28
  29static inline void gfs2_write_calc_reserv(const struct gfs2_inode *ip,
  30                                          unsigned int len,
  31                                          unsigned int *data_blocks,
  32                                          unsigned int *ind_blocks)
  33{
  34        const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
  35        unsigned int tmp;
  36
  37        BUG_ON(gfs2_is_dir(ip));
  38        *data_blocks = (len >> sdp->sd_sb.sb_bsize_shift) + 3;
  39        *ind_blocks = 3 * (sdp->sd_max_height - 1);
  40
  41        for (tmp = *data_blocks; tmp > sdp->sd_diptrs;) {
  42                tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs);
  43                *ind_blocks += tmp;
  44        }
  45}
  46
  47extern int gfs2_unstuff_dinode(struct gfs2_inode *ip, struct page *page);
  48extern int gfs2_block_map(struct inode *inode, sector_t lblock,
  49                          struct buffer_head *bh, int create);
  50extern int gfs2_extent_map(struct inode *inode, u64 lblock, int *new,
  51                           u64 *dblock, unsigned *extlen);
  52extern int gfs2_setattr_size(struct inode *inode, u64 size);
  53extern void gfs2_trim_blocks(struct inode *inode);
  54extern int gfs2_truncatei_resume(struct gfs2_inode *ip);
  55extern int gfs2_file_dealloc(struct gfs2_inode *ip);
  56extern int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset,
  57                                     unsigned int len);
  58
  59#endif /* __BMAP_DOT_H__ */
  60