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        /* total number of bytes that may be used for this inode for
 107         * delalloc
 108         */
 109        u64 reserved_bytes;
 110
 111        /*
 112         * the size of the file stored in the metadata on disk.  data=ordered
 113         * means the in-memory i_size might be larger than the size on disk
 114         * because not all the blocks are written yet.
 115         */
 116        u64 disk_i_size;
 117
 118        /* flags field from the on disk inode */
 119        u32 flags;
 120
 121        /*
 122         * if this is a directory then index_cnt is the counter for the index
 123         * number for new files that are created
 124         */
 125        u64 index_cnt;
 126
 127        /* the fsync log has some corner cases that mean we have to check
 128         * directories to see if any unlinks have been done before
 129         * the directory was logged.  See tree-log.c for all the
 130         * details
 131         */
 132        u64 last_unlink_trans;
 133
 134        /*
 135         * Counters to keep track of the number of extent item's we may use due
 136         * to delalloc and such.  outstanding_extents is the number of extent
 137         * items we think we'll end up using, and reserved_extents is the number
 138         * of extent items we've reserved metadata for.
 139         */
 140        unsigned outstanding_extents;
 141        unsigned reserved_extents;
 142
 143        /*
 144         * ordered_data_close is set by truncate when a file that used
 145         * to have good data has been truncated to zero.  When it is set
 146         * the btrfs file release call will add this inode to the
 147         * ordered operations list so that we make sure to flush out any
 148         * new data the application may have written before commit.
 149         *
 150         * yes, its silly to have a single bitflag, but we might grow more
 151         * of these.
 152         */
 153        unsigned ordered_data_close:1;
 154        unsigned orphan_meta_reserved:1;
 155        unsigned dummy_inode:1;
 156        unsigned in_defrag:1;
 157
 158        /*
 159         * always compress this one file
 160         */
 161        unsigned force_compress:4;
 162
 163        struct btrfs_delayed_node *delayed_node;
 164
 165        struct inode vfs_inode;
 166};
 167
 168extern unsigned char btrfs_filetype_table[];
 169
 170static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
 171{
 172        return container_of(inode, struct btrfs_inode, vfs_inode);
 173}
 174
 175static inline u64 btrfs_ino(struct inode *inode)
 176{
 177        u64 ino = BTRFS_I(inode)->location.objectid;
 178
 179        /*
 180         * !ino: btree_inode
 181         * type == BTRFS_ROOT_ITEM_KEY: subvol dir
 182         */
 183        if (!ino || BTRFS_I(inode)->location.type == BTRFS_ROOT_ITEM_KEY)
 184                ino = inode->i_ino;
 185        return ino;
 186}
 187
 188static inline void btrfs_i_size_write(struct inode *inode, u64 size)
 189{
 190        i_size_write(inode, size);
 191        BTRFS_I(inode)->disk_i_size = size;
 192}
 193
 194static inline bool btrfs_is_free_space_inode(struct btrfs_root *root,
 195                                       struct inode *inode)
 196{
 197        if (root == root->fs_info->tree_root ||
 198            BTRFS_I(inode)->location.objectid == BTRFS_FREE_INO_OBJECTID)
 199                return true;
 200        return false;
 201}
 202
 203#endif
 204