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  * Written by Ryusuke Konishi <ryusuke@osrg.net>
  17  */
  18
  19 #ifndef _NILFS_MDT_H
  20 #define _NILFS_MDT_H
  21
  22 #include <linux/buffer_head.h>
  23 #include <linux/blockgroup_lock.h>
  24 #include "nilfs.h"
  25 #include "page.h"
  26
  27 /**
  28  * struct nilfs_shadow_map - shadow mapping of meta data file
  29  * @bmap_store: shadow copy of bmap state
  30  * @frozen_data: shadowed dirty data pages
  31  * @frozen_btnodes: shadowed dirty b-tree nodes' pages
  32  * @frozen_buffers: list of frozen buffers
  33  */
  34 struct nilfs_shadow_map {
  35         struct nilfs_bmap_store bmap_store;
  36         struct address_space frozen_data;
  37         struct address_space frozen_btnodes;
  38         struct list_head frozen_buffers;
  39 };
  40
  41 /**
  42  * struct nilfs_mdt_info - on-memory private data of meta data files
  43  * @mi_sem: reader/writer semaphore for meta data operations
  44  * @mi_bgl: per-blockgroup locking
  45  * @mi_entry_size: size of an entry
  46  * @mi_first_entry_offset: offset to the first entry
  47  * @mi_entries_per_block: number of entries in a block
  48  * @mi_palloc_cache: persistent object allocator cache
  49  * @mi_shadow: shadow of bmap and page caches
  50  * @mi_blocks_per_group: number of blocks in a group
  51  * @mi_blocks_per_desc_block: number of blocks per descriptor block
  52  */
  53 struct nilfs_mdt_info {
  54         struct rw_semaphore     mi_sem;
  55         struct blockgroup_lock *mi_bgl;
  56         unsigned                mi_entry_size;
  57         unsigned                mi_first_entry_offset;
  58         unsigned long           mi_entries_per_block;
  59         struct nilfs_palloc_cache *mi_palloc_cache;
  60         struct nilfs_shadow_map *mi_shadow;
  61         unsigned long           mi_blocks_per_group;
  62         unsigned long           mi_blocks_per_desc_block;
  63 };
  64
  65 static inline struct nilfs_mdt_info *NILFS_MDT(const struct inode *inode)
  66 {
  67         return inode->i_private;
  68 }
  69
  70 /* Default GFP flags using highmem */
  71 #define NILFS_MDT_GFP      (__GFP_RECLAIM | __GFP_IO | __GFP_HIGHMEM)
  72
  73 int nilfs_mdt_get_block(struct inode *, unsigned long, int,
  74                         void (*init_block)(struct inode *,
  75                                            struct buffer_head *, void *),
  76                         struct buffer_head **);
  77 int nilfs_mdt_find_block(struct inode *inode, unsigned long start,
  78                          unsigned long end, unsigned long *blkoff,
  79                          struct buffer_head **out_bh);
  80 int nilfs_mdt_delete_block(struct inode *, unsigned long);
  81 int nilfs_mdt_forget_block(struct inode *, unsigned long);
  82 int nilfs_mdt_mark_block_dirty(struct inode *, unsigned long);
  83 int nilfs_mdt_fetch_dirty(struct inode *);
  84
  85 int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz);
  86 void nilfs_mdt_set_entry_size(struct inode *, unsigned, unsigned);
  87
  88 int nilfs_mdt_setup_shadow_map(struct inode *inode,
  89                                struct nilfs_shadow_map *shadow);
  90 int nilfs_mdt_save_to_shadow_map(struct inode *inode);
  91 void nilfs_mdt_restore_from_shadow_map(struct inode *inode);
  92 void nilfs_mdt_clear_shadow_map(struct inode *inode);
  93 int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh);
  94 struct buffer_head *nilfs_mdt_get_frozen_buffer(struct inode *inode,
  95                                                 struct buffer_head *bh);
  96
  97 static inline void nilfs_mdt_mark_dirty(struct inode *inode)
  98 {
  99         if (!test_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state))
 100                 set_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state);
 101 }
 102
 103 static inline void nilfs_mdt_clear_dirty(struct inode *inode)
 104 {
 105         clear_bit(NILFS_I_DIRTY, &NILFS_I(inode)->i_state);
 106 }
 107
 108 static inline __u64 nilfs_mdt_cno(struct inode *inode)
 109 {
 110         return ((struct the_nilfs *)inode->i_sb->s_fs_info)->ns_cno;
 111 }
 112
 113 static inline spinlock_t *
 114 nilfs_mdt_bgl_lock(struct inode *inode, unsigned int block_group)
 115 {
 116         return bgl_lock_ptr(NILFS_MDT(inode)->mi_bgl, block_group);
 117 }
 118
 119 #endif /* _NILFS_MDT_H */