LXR linux/fs/btrfs/btrfs

   1/*
   2 * Copyright (C) 2007 Oracle.  All rights reserved.
   3 *
   4 * This program is free software; you can redistribute it and/or
   5 * modify it under the terms of the GNU General Public
   6 * License v2 as published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope that it will be useful,
   9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11 * General Public License for more details.
  12 *
  13 * You should have received a copy of the GNU General Public
  14 * License along with this program; if not, write to the
  15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16 * Boston, MA 021110-1307, USA.
  17 */
  18
  19#ifndef __BTRFS_I__
  20#define __BTRFS_I__
  21
  22#include "extent_map.h"
  23#include "extent_io.h"
  24#include "ordered-data.h"
  25
  26/* in memory btrfs inode */
  27struct btrfs_inode {
  28        /* which subvolume this inode belongs to */
  29        struct btrfs_root *root;
  30
  31        /* key used to find this inode on disk.  This is used by the code
  32         * to read in roots of subvolumes
  33         */
  34        struct btrfs_key location;
  35
  36        /* the extent_tree has caches of all the extent mappings to disk */
  37        struct extent_map_tree extent_tree;
  38
  39        /* the io_tree does range state (DIRTY, LOCKED etc) */
  40        struct extent_io_tree io_tree;
  41
  42        /* special utility tree used to record which mirrors have already been
  43         * tried when checksums fail for a given block
  44         */
  45        struct extent_io_tree io_failure_tree;
  46
  47        /* held while inesrting or deleting extents from files */
  48        struct mutex extent_mutex;
  49
  50        /* held while logging the inode in tree-log.c */
  51        struct mutex log_mutex;
  52
  53        /* used to order data wrt metadata */
  54        struct btrfs_ordered_inode_tree ordered_tree;
  55
  56        /* for keeping track of orphaned inodes */
  57        struct list_head i_orphan;
  58
  59        /* list of all the delalloc inodes in the FS.  There are times we need
  60         * to write all the delalloc pages to disk, and this list is used
  61         * to walk them all.
  62         */
  63        struct list_head delalloc_inodes;
  64
  65        /*
  66         * list for tracking inodes that must be sent to disk before a
  67         * rename or truncate commit
  68         */
  69        struct list_head ordered_operations;
  70
  71        /* node for the red-black tree that links inodes in subvolume root */
  72        struct rb_node rb_node;
  73
  74        /* the space_info for where this inode's data allocations are done */
  75        struct btrfs_space_info *space_info;
  76
  77        /* full 64 bit generation number, struct vfs_inode doesn't have a big
  78         * enough field for this.
  79         */
  80        u64 generation;
  81
  82        /* sequence number for NFS changes */
  83        u64 sequence;
  84
  85        /*
  86         * transid of the trans_handle that last modified this inode
  87         */
  88        u64 last_trans;
  89
  90        /*
  91         * log transid when this inode was last modified
  92         */
  93        u64 last_sub_trans;
  94
  95        /*
  96         * transid that last logged this inode
  97         */
  98        u64 logged_trans;
  99
 100        /* total number of bytes pending delalloc, used by stat to calc the
 101         * real block usage of the file
 102         */
 103        u64 delalloc_bytes;
 104
 105        /* total number of bytes that may be used for this inode for
 106         * delalloc
 107         */
 108        u64 reserved_bytes;
 109
 110        /*
 111         * the size of the file stored in the metadata on disk.  data=ordered
 112         * means the in-memory i_size might be larger than the size on disk
 113         * because not all the blocks are written yet.
 114         */
 115        u64 disk_i_size;
 116
 117        /* flags field from the on disk inode */
 118        u32 flags;
 119
 120        /*
 121         * if this is a directory then index_cnt is the counter for the index
 122         * number for new files that are created
 123         */
 124        u64 index_cnt;
 125
 126        /* the start of block group preferred for allocations. */
 127        u64 block_group;
 128
 129        /* the fsync log has some corner cases that mean we have to check
 130         * directories to see if any unlinks have been done before
 131         * the directory was logged.  See tree-log.c for all the
 132         * details
 133         */
 134        u64 last_unlink_trans;
 135
 136        /*
 137         * Counters to keep track of the number of extent item's we may use due
 138         * to delalloc and such.  outstanding_extents is the number of extent
 139         * items we think we'll end up using, and reserved_extents is the number
 140         * of extent items we've reserved metadata for.
 141         */
 142        spinlock_t accounting_lock;
 143        int reserved_extents;
 144        int outstanding_extents;
 145
 146        /*
 147         * ordered_data_close is set by truncate when a file that used
 148         * to have good data has been truncated to zero.  When it is set
 149         * the btrfs file release call will add this inode to the
 150         * ordered operations list so that we make sure to flush out any
 151         * new data the application may have written before commit.
 152         *
 153         * yes, its silly to have a single bitflag, but we might grow more
 154         * of these.
 155         */
 156        unsigned ordered_data_close:1;
 157        unsigned dummy_inode:1;
 158
 159        struct inode vfs_inode;
 160};
 161
 162static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
 163{
 164        return container_of(inode, struct btrfs_inode, vfs_inode);
 165}
 166
 167static inline void btrfs_i_size_write(struct inode *inode, u64 size)
 168{
 169        inode->i_size = size;
 170        BTRFS_I(inode)->disk_i_size = size;
 171}
 172
 173#endif
 174