fs/nilfs2/page.h

   1 /*
   2  * page.h - buffer/page management specific to NILFS
   3  *
   4  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * Written by Ryusuke Konishi <ryusuke@osrg.net>,
  17  *            Seiji Kihara <kihara@osrg.net>.
  18  */
  19
  20 #ifndef _NILFS_PAGE_H
  21 #define _NILFS_PAGE_H
  22
  23 #include <linux/buffer_head.h>
  24 #include "nilfs.h"
  25
  26 /*
  27  * Extended buffer state bits
  28  */
  29 enum {
  30         BH_NILFS_Allocated = BH_PrivateStart,
  31         BH_NILFS_Node,
  32         BH_NILFS_Volatile,
  33         BH_NILFS_Checked,
  34         BH_NILFS_Redirected,
  35 };
  36
  37 BUFFER_FNS(NILFS_Node, nilfs_node)              /* nilfs node buffers */
  38 BUFFER_FNS(NILFS_Volatile, nilfs_volatile)
  39 BUFFER_FNS(NILFS_Checked, nilfs_checked)        /* buffer is verified */
  40 BUFFER_FNS(NILFS_Redirected, nilfs_redirected)  /* redirected to a copy */
  41
  42
  43 int __nilfs_clear_page_dirty(struct page *);
  44
  45 struct buffer_head *nilfs_grab_buffer(struct inode *, struct address_space *,
  46                                       unsigned long, unsigned long);
  47 void nilfs_forget_buffer(struct buffer_head *);
  48 void nilfs_copy_buffer(struct buffer_head *, struct buffer_head *);
  49 int nilfs_page_buffers_clean(struct page *);
  50 void nilfs_page_bug(struct page *);
  51
  52 int nilfs_copy_dirty_pages(struct address_space *, struct address_space *);
  53 void nilfs_copy_back_pages(struct address_space *, struct address_space *);
  54 void nilfs_clear_dirty_page(struct page *, bool);
  55 void nilfs_clear_dirty_pages(struct address_space *, bool);
  56 void nilfs_mapping_init(struct address_space *mapping, struct inode *inode);
  57 unsigned nilfs_page_count_clean_buffers(struct page *, unsigned, unsigned);
  58 unsigned long nilfs_find_uncommitted_extent(struct inode *inode,
  59                                             sector_t start_blk,
  60                                             sector_t *blkoff);
  61
  62 #define NILFS_PAGE_BUG(page, m, a...) \
  63         do { nilfs_page_bug(page); BUG(); } while (0)
  64
  65 static inline struct buffer_head *
  66 nilfs_page_get_nth_block(struct page *page, unsigned int count)
  67 {
  68         struct buffer_head *bh = page_buffers(page);
  69
  70         while (count-- > 0)
  71                 bh = bh->b_this_page;
  72         get_bh(bh);
  73         return bh;
  74 }
  75
  76 #endif /* _NILFS_PAGE_H */