LXR linux/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 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19 *
  20 * Written by Ryusuke Konishi <ryusuke@osrg.net>,
  21 *            Seiji Kihara <kihara@osrg.net>.
  22 */
  23
  24#ifndef _NILFS_PAGE_H
  25#define _NILFS_PAGE_H
  26
  27#include <linux/buffer_head.h>
  28#include "nilfs.h"
  29
  30/*
  31 * Extended buffer state bits
  32 */
  33enum {
  34        BH_NILFS_Allocated = BH_PrivateStart,
  35        BH_NILFS_Node,
  36        BH_NILFS_Volatile,
  37        BH_NILFS_Checked,
  38        BH_NILFS_Redirected,
  39};
  40
  41BUFFER_FNS(NILFS_Node, nilfs_node)              /* nilfs node buffers */
  42BUFFER_FNS(NILFS_Volatile, nilfs_volatile)
  43BUFFER_FNS(NILFS_Checked, nilfs_checked)        /* buffer is verified */
  44BUFFER_FNS(NILFS_Redirected, nilfs_redirected)  /* redirected to a copy */
  45
  46
  47int __nilfs_clear_page_dirty(struct page *);
  48
  49struct buffer_head *nilfs_grab_buffer(struct inode *, struct address_space *,
  50                                      unsigned long, unsigned long);
  51void nilfs_forget_buffer(struct buffer_head *);
  52void nilfs_copy_buffer(struct buffer_head *, struct buffer_head *);
  53int nilfs_page_buffers_clean(struct page *);
  54void nilfs_page_bug(struct page *);
  55
  56int nilfs_copy_dirty_pages(struct address_space *, struct address_space *);
  57void nilfs_copy_back_pages(struct address_space *, struct address_space *);
  58void nilfs_clear_dirty_page(struct page *, bool);
  59void nilfs_clear_dirty_pages(struct address_space *, bool);
  60void nilfs_mapping_init(struct address_space *mapping, struct inode *inode,
  61                        struct backing_dev_info *bdi);
  62unsigned nilfs_page_count_clean_buffers(struct page *, unsigned, unsigned);
  63unsigned long nilfs_find_uncommitted_extent(struct inode *inode,
  64                                            sector_t start_blk,
  65                                            sector_t *blkoff);
  66
  67#define NILFS_PAGE_BUG(page, m, a...) \
  68        do { nilfs_page_bug(page); BUG(); } while (0)
  69
  70static inline struct buffer_head *
  71nilfs_page_get_nth_block(struct page *page, unsigned int count)
  72{
  73        struct buffer_head *bh = page_buffers(page);
  74
  75        while (count-- > 0)
  76                bh = bh->b_this_page;
  77        get_bh(bh);
  78        return bh;
  79}
  80
  81#endif /* _NILFS_PAGE_H */
  82