fs/btrfs/btrfs_inode.h

   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 /*
  28  * ordered_data_close is set by truncate when a file that used
  29  * to have good data has been truncated to zero.  When it is set
  30  * the btrfs file release call will add this inode to the
  31  * ordered operations list so that we make sure to flush out any
  32  * new data the application may have written before commit.
  33  */
  34 #define BTRFS_INODE_ORDERED_DATA_CLOSE          0
  35 #define BTRFS_INODE_ORPHAN_META_RESERVED        1
  36 #define BTRFS_INODE_DUMMY                       2
  37 #define BTRFS_INODE_IN_DEFRAG                   3
  38 #define BTRFS_INODE_DELALLOC_META_RESERVED      4
  39 #define BTRFS_INODE_HAS_ORPHAN_ITEM             5
  40 #define BTRFS_INODE_HAS_ASYNC_EXTENT            6
  41 #define BTRFS_INODE_NEEDS_FULL_SYNC             7
  42 #define BTRFS_INODE_COPY_EVERYTHING             8
  43 #define BTRFS_INODE_IN_DELALLOC_LIST            9
  44 #define BTRFS_INODE_READDIO_NEED_LOCK           10
  45
  46 /* in memory btrfs inode */
  47 struct btrfs_inode {
  48         /* which subvolume this inode belongs to */
  49         struct btrfs_root *root;
  50
  51         /* key used to find this inode on disk.  This is used by the code
  52          * to read in roots of subvolumes
  53          */
  54         struct btrfs_key location;
  55
  56         /* Lock for counters */
  57         spinlock_t lock;
  58
  59         /* the extent_tree has caches of all the extent mappings to disk */
  60         struct extent_map_tree extent_tree;
  61
  62         /* the io_tree does range state (DIRTY, LOCKED etc) */
  63         struct extent_io_tree io_tree;
  64
  65         /* special utility tree used to record which mirrors have already been
  66          * tried when checksums fail for a given block
  67          */
  68         struct extent_io_tree io_failure_tree;
  69
  70         /* held while logging the inode in tree-log.c */
  71         struct mutex log_mutex;
  72
  73         /* held while doing delalloc reservations */
  74         struct mutex delalloc_mutex;
  75
  76         /* used to order data wrt metadata */
  77         struct btrfs_ordered_inode_tree ordered_tree;
  78
  79         /* list of all the delalloc inodes in the FS.  There are times we need
  80          * to write all the delalloc pages to disk, and this list is used
  81          * to walk them all.
  82          */
  83         struct list_head delalloc_inodes;
  84
  85         /*
  86          * list for tracking inodes that must be sent to disk before a
  87          * rename or truncate commit
  88          */
  89         struct list_head ordered_operations;
  90
  91         /* node for the red-black tree that links inodes in subvolume root */
  92         struct rb_node rb_node;
  93
  94         unsigned long runtime_flags;
  95
  96         /* Keep track of who's O_SYNC/fsyncing currently */
  97         atomic_t sync_writers;
  98
  99         /* full 64 bit generation number, struct vfs_inode doesn't have a big
 100          * enough field for this.
 101          */
 102         u64 generation;
 103
 104         /*
 105          * transid of the trans_handle that last modified this inode
 106          */
 107         u64 last_trans;
 108
 109         /*
 110          * log transid when this inode was last modified
 111          */
 112         u64 last_sub_trans;
 113
 114         /*
 115          * transid that last logged this inode
 116          */
 117         u64 logged_trans;
 118
 119         /* total number of bytes pending delalloc, used by stat to calc the
 120          * real block usage of the file
 121          */
 122         u64 delalloc_bytes;
 123
 124         /*
 125          * the size of the file stored in the metadata on disk.  data=ordered
 126          * means the in-memory i_size might be larger than the size on disk
 127          * because not all the blocks are written yet.
 128          */
 129         u64 disk_i_size;
 130
 131         /*
 132          * if this is a directory then index_cnt is the counter for the index
 133          * number for new files that are created
 134          */
 135         u64 index_cnt;
 136
 137         /* the fsync log has some corner cases that mean we have to check
 138          * directories to see if any unlinks have been done before
 139          * the directory was logged.  See tree-log.c for all the
 140          * details
 141          */
 142         u64 last_unlink_trans;
 143
 144         /*
 145          * Number of bytes outstanding that are going to need csums.  This is
 146          * used in ENOSPC accounting.
 147          */
 148         u64 csum_bytes;
 149
 150         /* flags field from the on disk inode */
 151         u32 flags;
 152
 153         /* a local copy of root's last_log_commit */
 154         unsigned long last_log_commit;
 155
 156         /*
 157          * Counters to keep track of the number of extent item's we may use due
 158          * to delalloc and such.  outstanding_extents is the number of extent
 159          * items we think we'll end up using, and reserved_extents is the number
 160          * of extent items we've reserved metadata for.
 161          */
 162         unsigned outstanding_extents;
 163         unsigned reserved_extents;
 164
 165         /*
 166          * always compress this one file
 167          */
 168         unsigned force_compress;
 169
 170         struct btrfs_delayed_node *delayed_node;
 171
 172         struct inode vfs_inode;
 173 };
 174
 175 extern unsigned char btrfs_filetype_table[];
 176
 177 static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
 178 {
 179         return container_of(inode, struct btrfs_inode, vfs_inode);
 180 }
 181
 182 static inline u64 btrfs_ino(struct inode *inode)
 183 {
 184         u64 ino = BTRFS_I(inode)->location.objectid;
 185
 186         /*
 187          * !ino: btree_inode
 188          * type == BTRFS_ROOT_ITEM_KEY: subvol dir
 189          */
 190         if (!ino || BTRFS_I(inode)->location.type == BTRFS_ROOT_ITEM_KEY)
 191                 ino = inode->i_ino;
 192         return ino;
 193 }
 194
 195 static inline void btrfs_i_size_write(struct inode *inode, u64 size)
 196 {
 197         i_size_write(inode, size);
 198         BTRFS_I(inode)->disk_i_size = size;
 199 }
 200
 201 static inline bool btrfs_is_free_space_inode(struct inode *inode)
 202 {
 203         struct btrfs_root *root = BTRFS_I(inode)->root;
 204
 205         if (root == root->fs_info->tree_root &&
 206             btrfs_ino(inode) != BTRFS_BTREE_INODE_OBJECTID)
 207                 return true;
 208         if (BTRFS_I(inode)->location.objectid == BTRFS_FREE_INO_OBJECTID)
 209                 return true;
 210         return false;
 211 }
 212
 213 static inline int btrfs_inode_in_log(struct inode *inode, u64 generation)
 214 {
 215         if (BTRFS_I(inode)->logged_trans == generation &&
 216             BTRFS_I(inode)->last_sub_trans <= BTRFS_I(inode)->last_log_commit)
 217                 return 1;
 218         return 0;
 219 }
 220
 221 /*
 222  * Disable DIO read nolock optimization, so new dio readers will be forced
 223  * to grab i_mutex. It is used to avoid the endless truncate due to
 224  * nonlocked dio read.
 225  */
 226 static inline void btrfs_inode_block_unlocked_dio(struct inode *inode)
 227 {
 228         set_bit(BTRFS_INODE_READDIO_NEED_LOCK, &BTRFS_I(inode)->runtime_flags);
 229         smp_mb();
 230 }
 231
 232 static inline void btrfs_inode_resume_unlocked_dio(struct inode *inode)
 233 {
 234         smp_mb__before_clear_bit();
 235         clear_bit(BTRFS_INODE_READDIO_NEED_LOCK,
 236                   &BTRFS_I(inode)->runtime_flags);
 237 }
 238
 239 #endif