release/src-rt-6.x.4708/linux/linux-2.6.36/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
  15 struct inode;
  16 struct gfs2_inode;
  17 struct 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
  29 static 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
  47 int gfs2_unstuff_dinode(struct gfs2_inode *ip, struct page *page);
  48 int gfs2_block_map(struct inode *inode, sector_t lblock, struct buffer_head *bh, int create);
  49 int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsigned *extlen);
  50
  51 int gfs2_truncatei(struct gfs2_inode *ip, u64 size);
  52 int gfs2_truncatei_resume(struct gfs2_inode *ip);
  53 int gfs2_file_dealloc(struct gfs2_inode *ip);
  54 int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset,
  55                               unsigned int len);
  56
  57 #endif /* __BMAP_DOT_H__ */