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 struct nilfs_shadow_map {
  32         struct nilfs_bmap_store bmap_store;
  33         struct address_space frozen_data;
  34         struct address_space frozen_btnodes;
  35         struct list_head frozen_buffers;
  36 };
  37
  38 /**
  39  * struct nilfs_mdt_info - on-memory private data of meta data files
  40  * @mi_nilfs: back pointer to the_nilfs struct
  41  * @mi_sem: reader/writer semaphore for meta data operations
  42  * @mi_bgl: per-blockgroup locking
  43  * @mi_entry_size: size of an entry
  44  * @mi_first_entry_offset: offset to the first entry
  45  * @mi_entries_per_block: number of entries in a block
  46  * @mi_palloc_cache: persistent object allocator cache
  47  * @mi_shadow: shadow of bmap and page caches
  48  * @mi_blocks_per_group: number of blocks in a group
  49  * @mi_blocks_per_desc_block: number of blocks per descriptor block
  50  */
  51 struct nilfs_mdt_info {
  52         struct the_nilfs       *mi_nilfs;
  53         struct rw_semaphore     mi_sem;
  54         struct blockgroup_lock *mi_bgl;
  55         unsigned                mi_entry_size;
  56         unsigned                mi_first_entry_offset;
  57         unsigned long           mi_entries_per_block;
  58         struct nilfs_palloc_cache *mi_palloc_cache;
  59         struct nilfs_shadow_map *mi_shadow;
  60         unsigned long           mi_blocks_per_group;
  61         unsigned long           mi_blocks_per_desc_block;
  62 };
  63
  64 static inline struct nilfs_mdt_info *NILFS_MDT(const struct inode *inode)
  65 {
  66         return inode->i_private;
  67 }
  68
  69 static inline struct the_nilfs *NILFS_I_NILFS(struct inode *inode)
  70 {
  71         struct super_block *sb = inode->i_sb;
  72
  73         return sb ? NILFS_SB(sb)->s_nilfs : NILFS_MDT(inode)->mi_nilfs;
  74 }
  75
  76 /* Default GFP flags using highmem */
  77 #define NILFS_MDT_GFP      (__GFP_WAIT | __GFP_IO | __GFP_HIGHMEM)
  78
  79 int nilfs_mdt_get_block(struct inode *, unsigned long, int,
  80                         void (*init_block)(struct inode *,
  81                                            struct buffer_head *, void *),
  82                         struct buffer_head **);
  83 int nilfs_mdt_delete_block(struct inode *, unsigned long);
  84 int nilfs_mdt_forget_block(struct inode *, unsigned long);
  85 int nilfs_mdt_mark_block_dirty(struct inode *, unsigned long);
  86 int nilfs_mdt_fetch_dirty(struct inode *);
  87
  88 int nilfs_mdt_init(struct inode *inode, struct the_nilfs *nilfs,
  89                    gfp_t gfp_mask, size_t objsz);
  90 struct inode *nilfs_mdt_new(struct the_nilfs *, struct super_block *, ino_t,
  91                             size_t);
  92 struct inode *nilfs_mdt_new_common(struct the_nilfs *, struct super_block *,
  93                                    ino_t);
  94 void nilfs_mdt_destroy(struct inode *);
  95 void nilfs_mdt_set_entry_size(struct inode *, unsigned, unsigned);
  96
  97 int nilfs_mdt_setup_shadow_map(struct inode *inode,
  98                                struct nilfs_shadow_map *shadow);
  99 int nilfs_mdt_save_to_shadow_map(struct inode *inode);
 100 void nilfs_mdt_restore_from_shadow_map(struct inode *inode);
 101 void nilfs_mdt_clear_shadow_map(struct inode *inode);
 102 int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh);
 103 struct buffer_head *nilfs_mdt_get_frozen_buffer(struct inode *inode,
 104                                                 struct buffer_head *bh);
 105
 106 #define nilfs_mdt_mark_buffer_dirty(bh) nilfs_mark_buffer_dirty(bh)
 107
 108 static inline void nilfs_mdt_mark_dirty(struct inode *inode)
 109 {
 110         if (!test_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state))
 111                 set_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state);
 112 }
 113
 114 static inline void nilfs_mdt_clear_dirty(struct inode *inode)
 115 {
 116         clear_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state);
 117 }
 118
 119 static inline __u64 nilfs_mdt_cno(struct inode *inode)
 120 {
 121         return NILFS_MDT(inode)->mi_nilfs->ns_cno;
 122 }
 123
 124 #define nilfs_mdt_bgl_lock(inode, bg) \
 125         (&NILFS_MDT(inode)->mi_bgl->locks[(bg) & (NR_BG_LOCKS-1)].lock)
 126
 127 #endif /* _NILFS_MDT_H */