fs/ocfs2/buffer_head_io.h

   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
  31 int ocfs2_write_block(struct ocfs2_super          *osb,
  32                       struct buffer_head  *bh,
  33                       struct ocfs2_caching_info   *ci);
  34 int 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  */
  44 int 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
  49 int 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
  55 static 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
  70 bail:
  71         return status;
  72 }
  73
  74 #endif /* OCFS2_BUFFER_HEAD_IO_H */