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#include "delayed-inode.h"
  26
  27/* in memory btrfs inode */
  28struct btrfs_inode {
  29        /* which subvolume this inode belongs to */
  30        struct btrfs_root *root;
  31
  32        /* key used to find this inode on disk.  This is used by the code
  33         * to read in roots of subvolumes
  34         */
  35        struct btrfs_key location;
  36
  37        /* Lock for counters */
  38        spinlock_t lock;
  39
  40        /* the extent_tree has caches of all the extent mappings to disk */
  41        struct extent_map_tree extent_tree;
  42
  43        /* the io_tree does range state (DIRTY, LOCKED etc) */
  44        struct extent_io_tree io_tree;
  45
  46        /* special utility tree used to record which mirrors have already been
  47         * tried when checksums fail for a given block
  48         */
  49        struct extent_io_tree io_failure_tree;
  50
  51        /* held while logging the inode in tree-log.c */
  52        struct mutex log_mutex;
  53
  54        /* used to order data wrt metadata */
  55        struct btrfs_ordered_inode_tree ordered_tree;
  56
  57        /* for keeping track of orphaned inodes */
  58        struct list_head i_orphan;
  59
  60        /* list of all the delalloc inodes in the FS.  There are times we need
  61         * to write all the delalloc pages to disk, and this list is used
  62         * to walk them all.
  63         */
  64        struct list_head delalloc_inodes;
  65
  66        /*
  67         * list for tracking inodes that must be sent to disk before a
  68         * rename or truncate commit
  69         */
  70        struct list_head ordered_operations;
  71
  72        /* node for the red-black tree that links inodes in subvolume root */
  73        struct rb_node rb_node;
  74
  75        /* the space_info for where this inode's data allocations are done */
  76        struct btrfs_space_info *space_info;
  77
  78        /* full 64 bit generation number, struct vfs_inode doesn't have a big
  79         * enough field for this.
  80         */
  81        u64 generation;
  82
  83        /* sequence number for NFS changes */
  84        u64 sequence;
  85
  86        /*
  87         * transid of the trans_handle that last modified this inode
  88         */
  89        u64 last_trans;
  90
  91        /*
  92         * log transid when this inode was last modified
  93         */
  94        u64 last_sub_trans;
  95
  96        /*
  97         * transid that last logged this inode
  98         */
  99        u64 logged_trans;
 100
 101        /* total number of bytes pending delalloc, used by stat to calc the
 102         * real block usage of the file
 103         */
 104        u64 delalloc_bytes;
 105
 106        /*
 107         * the size of the file stored in the metadata on disk.  data=ordered
 108         * means the in-memory i_size might be larger than the size on disk
 109         * because not all the blocks are written yet.
 110         */
 111        u64 disk_i_size;
 112
 113        /*
 114         * if this is a directory then index_cnt is the counter for the index
 115         * number for new files that are created
 116         */
 117        u64 index_cnt;
 118
 119        /* the fsync log has some corner cases that mean we have to check
 120         * directories to see if any unlinks have been done before
 121         * the directory was logged.  See tree-log.c for all the
 122         * details
 123         */
 124        u64 last_unlink_trans;
 125
 126        /*
 127         * Number of bytes outstanding that are going to need csums.  This is
 128         * used in ENOSPC accounting.
 129         */
 130        u64 csum_bytes;
 131
 132        /* flags field from the on disk inode */
 133        u32 flags;
 134
 135        /*
 136         * Counters to keep track of the number of extent item's we may use due
 137         * to delalloc and such.  outstanding_extents is the number of extent
 138         * items we think we'll end up using, and reserved_extents is the number
 139         * of extent items we've reserved metadata for.
 140         */
 141        unsigned outstanding_extents;
 142        unsigned reserved_extents;
 143
 144        /*
 145         * ordered_data_close is set by truncate when a file that used
 146         * to have good data has been truncated to zero.  When it is set
 147         * the btrfs file release call will add this inode to the
 148         * ordered operations list so that we make sure to flush out any
 149         * new data the application may have written before commit.
 150         */
 151        unsigned ordered_data_close:1;
 152        unsigned orphan_meta_reserved:1;
 153        unsigned dummy_inode:1;
 154        unsigned in_defrag:1;
 155        unsigned delalloc_meta_reserved:1;
 156
 157        /*
 158         * always compress this one file
 159         */
 160        unsigned force_compress:4;
 161
 162        struct btrfs_delayed_node *delayed_node;
 163
 164        struct inode vfs_inode;
 165};
 166
 167extern unsigned char btrfs_filetype_table[];
 168
 169static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
 170{
 171        return container_of(inode, struct btrfs_inode, vfs_inode);
 172}
 173
 174static inline u64 btrfs_ino(struct inode *inode)
 175{
 176        u64 ino = BTRFS_I(inode)->location.objectid;
 177
 178        /*
 179         * !ino: btree_inode
 180         * type == BTRFS_ROOT_ITEM_KEY: subvol dir
 181         */
 182        if (!ino || BTRFS_I(inode)->location.type == BTRFS_ROOT_ITEM_KEY)
 183                ino = inode->i_ino;
 184        return ino;
 185}
 186
 187static inline void btrfs_i_size_write(struct inode *inode, u64 size)
 188{
 189        i_size_write(inode, size);
 190        BTRFS_I(inode)->disk_i_size = size;
 191}
 192
 193static inline bool btrfs_is_free_space_inode(struct btrfs_root *root,
 194                                       struct inode *inode)
 195{
 196        if (root == root->fs_info->tree_root ||
 197            BTRFS_I(inode)->location.objectid == BTRFS_FREE_INO_OBJECTID)
 198                return true;
 199        return false;
 200}
 201
 202#endif
 203