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  */
  33 enum {
  34         BH_NILFS_Allocated = BH_PrivateStart,
  35         BH_NILFS_Node,
  36         BH_NILFS_Volatile,
  37         BH_NILFS_Checked,
  38         BH_NILFS_Redirected,
  39 };
  40
  41 BUFFER_FNS(NILFS_Node, nilfs_node)              /* nilfs node buffers */
  42 BUFFER_FNS(NILFS_Volatile, nilfs_volatile)
  43 BUFFER_FNS(NILFS_Checked, nilfs_checked)        /* buffer is verified */
  44 BUFFER_FNS(NILFS_Redirected, nilfs_redirected)  /* redirected to a copy */
  45
  46
  47 int __nilfs_clear_page_dirty(struct page *);
  48
  49 struct buffer_head *nilfs_grab_buffer(struct inode *, struct address_space *,
  50                                       unsigned long, unsigned long);
  51 void nilfs_forget_buffer(struct buffer_head *);
  52 void nilfs_copy_buffer(struct buffer_head *, struct buffer_head *);
  53 int nilfs_page_buffers_clean(struct page *);
  54 void nilfs_page_bug(struct page *);
  55
  56 int nilfs_copy_dirty_pages(struct address_space *, struct address_space *);
  57 void nilfs_copy_back_pages(struct address_space *, struct address_space *);
  58 void nilfs_clear_dirty_pages(struct address_space *);
  59 void nilfs_mapping_init(struct address_space *mapping, struct inode *inode,
  60                         struct backing_dev_info *bdi);
  61 unsigned nilfs_page_count_clean_buffers(struct page *, unsigned, unsigned);
  62 unsigned long nilfs_find_uncommitted_extent(struct inode *inode,
  63                                             sector_t start_blk,
  64                                             sector_t *blkoff);
  65
  66 #define NILFS_PAGE_BUG(page, m, a...) \
  67         do { nilfs_page_bug(page); BUG(); } while (0)
  68
  69 static inline struct buffer_head *
  70 nilfs_page_get_nth_block(struct page *page, unsigned int count)
  71 {
  72         struct buffer_head *bh = page_buffers(page);
  73
  74         while (count-- > 0)
  75                 bh = bh->b_this_page;
  76         get_bh(bh);
  77         return bh;
  78 }
  79
  80 #endif /* _NILFS_PAGE_H */