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