fs/nilfs2/mdt.h

   1 /*
   2  * mdt.h - NILFS meta data file prototype and definitions
   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  */
  22
  23 #ifndef _NILFS_MDT_H
  24 #define _NILFS_MDT_H
  25
  26 #include <linux/buffer_head.h>
  27 #include <linux/blockgroup_lock.h>
  28 #include "nilfs.h"
  29 #include "page.h"
  30
  31 /**
  32  * struct nilfs_shadow_map - shadow mapping of meta data file
  33  * @bmap_store: shadow copy of bmap state
  34  * @frozen_data: shadowed dirty data pages
  35  * @frozen_btnodes: shadowed dirty b-tree nodes' pages
  36  * @frozen_buffers: list of frozen buffers
  37  */
  38 struct nilfs_shadow_map {
  39         struct nilfs_bmap_store bmap_store;
  40         struct address_space frozen_data;
  41         struct address_space frozen_btnodes;
  42         struct list_head frozen_buffers;
  43 };
  44
  45 /**
  46  * struct nilfs_mdt_info - on-memory private data of meta data files
  47  * @mi_sem: reader/writer semaphore for meta data operations
  48  * @mi_bgl: per-blockgroup locking
  49  * @mi_entry_size: size of an entry
  50  * @mi_first_entry_offset: offset to the first entry
  51  * @mi_entries_per_block: number of entries in a block
  52  * @mi_palloc_cache: persistent object allocator cache
  53  * @mi_shadow: shadow of bmap and page caches
  54  * @mi_blocks_per_group: number of blocks in a group
  55  * @mi_blocks_per_desc_block: number of blocks per descriptor block
  56  */
  57 struct nilfs_mdt_info {
  58         struct rw_semaphore     mi_sem;
  59         struct blockgroup_lock *mi_bgl;
  60         unsigned                mi_entry_size;
  61         unsigned                mi_first_entry_offset;
  62         unsigned long           mi_entries_per_block;
  63         struct nilfs_palloc_cache *mi_palloc_cache;
  64         struct nilfs_shadow_map *mi_shadow;
  65         unsigned long           mi_blocks_per_group;
  66         unsigned long           mi_blocks_per_desc_block;
  67 };
  68
  69 static inline struct nilfs_mdt_info *NILFS_MDT(const struct inode *inode)
  70 {
  71         return inode->i_private;
  72 }
  73
  74 /* Default GFP flags using highmem */
  75 #define NILFS_MDT_GFP      (__GFP_WAIT | __GFP_IO | __GFP_HIGHMEM)
  76
  77 int nilfs_mdt_get_block(struct inode *, unsigned long, int,
  78                         void (*init_block)(struct inode *,
  79                                            struct buffer_head *, void *),
  80                         struct buffer_head **);
  81 int nilfs_mdt_delete_block(struct inode *, unsigned long);
  82 int nilfs_mdt_forget_block(struct inode *, unsigned long);
  83 int nilfs_mdt_mark_block_dirty(struct inode *, unsigned long);
  84 int nilfs_mdt_fetch_dirty(struct inode *);
  85
  86 int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz);
  87 void nilfs_mdt_set_entry_size(struct inode *, unsigned, unsigned);
  88
  89 int nilfs_mdt_setup_shadow_map(struct inode *inode,
  90                                struct nilfs_shadow_map *shadow);
  91 int nilfs_mdt_save_to_shadow_map(struct inode *inode);
  92 void nilfs_mdt_restore_from_shadow_map(struct inode *inode);
  93 void nilfs_mdt_clear_shadow_map(struct inode *inode);
  94 int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh);
  95 struct buffer_head *nilfs_mdt_get_frozen_buffer(struct inode *inode,
  96                                                 struct buffer_head *bh);
  97
  98 static inline void nilfs_mdt_mark_dirty(struct inode *inode)
  99 {
 100         if (!test_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state))
 101                 set_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state);
 102 }
 103
 104 static inline void nilfs_mdt_clear_dirty(struct inode *inode)
 105 {
 106         clear_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state);
 107 }
 108
 109 static inline __u64 nilfs_mdt_cno(struct inode *inode)
 110 {
 111         return ((struct the_nilfs *)inode->i_sb->s_fs_info)->ns_cno;
 112 }
 113
 114 #define nilfs_mdt_bgl_lock(inode, bg) \
 115         (&NILFS_MDT(inode)->mi_bgl->locks[(bg) & (NR_BG_LOCKS-1)].lock)
 116
 117 #endif /* _NILFS_MDT_H */