LXR linux/fs/ocfs2/buffer_head

   1/* -*- mode: c; c-basic-offset: 8; -*-
   2 * vim: noexpandtab sw=8 ts=8 sts=0:
   3 *
   4 * ocfs2_buffer_head.h
   5 *
   6 * Buffer cache handling functions defined
   7 *
   8 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
   9 *
  10 * This program is free software; you can redistribute it and/or
  11 * modify it under the terms of the GNU General Public
  12 * License as published by the Free Software Foundation; either
  13 * version 2 of the License, or (at your option) any later version.
  14 *
  15 * This program is distributed in the hope that it will be useful,
  16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18 * General Public License for more details.
  19 *
  20 * You should have received a copy of the GNU General Public
  21 * License along with this program; if not, write to the
  22 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 * Boston, MA 021110-1307, USA.
  24 */
  25
  26#ifndef OCFS2_BUFFER_HEAD_IO_H
  27#define OCFS2_BUFFER_HEAD_IO_H
  28
  29#include <linux/buffer_head.h>
  30
  31int ocfs2_write_block(struct ocfs2_super          *osb,
  32                      struct buffer_head  *bh,
  33                      struct ocfs2_caching_info   *ci);
  34int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,
  35                           unsigned int nr, struct buffer_head *bhs[]);
  36
  37/*
  38 * If not NULL, validate() will be called on a buffer that is freshly
  39 * read from disk.  It will not be called if the buffer was in cache.
  40 * Note that if validate() is being used for this buffer, it needs to
  41 * be set even for a READAHEAD call, as it marks the buffer for later
  42 * validation.
  43 */
  44int ocfs2_read_blocks(struct ocfs2_caching_info *ci, u64 block, int nr,
  45                      struct buffer_head *bhs[], int flags,
  46                      int (*validate)(struct super_block *sb,
  47                                      struct buffer_head *bh));
  48
  49int ocfs2_write_super_or_backup(struct ocfs2_super *osb,
  50                                struct buffer_head *bh);
  51
  52#define OCFS2_BH_IGNORE_CACHE      1
  53#define OCFS2_BH_READAHEAD         8
  54
  55static inline int ocfs2_read_block(struct ocfs2_caching_info *ci, u64 off,
  56                                   struct buffer_head **bh,
  57                                   int (*validate)(struct super_block *sb,
  58                                                   struct buffer_head *bh))
  59{
  60        int status = 0;
  61
  62        if (bh == NULL) {
  63                printk("ocfs2: bh == NULL\n");
  64                status = -EINVAL;
  65                goto bail;
  66        }
  67
  68        status = ocfs2_read_blocks(ci, off, 1, bh, 0, validate);
  69
  70bail:
  71        return status;
  72}
  73
  74#endif /* OCFS2_BUFFER_HEAD_IO_H */
  75