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 <linux/hash.h>
  23 #include "extent_map.h"
  24 #include "extent_io.h"
  25 #include "ordered-data.h"
  26 #include "delayed-inode.h"
  27
  28 /*
  29  * ordered_data_close is set by truncate when a file that used
  30  * to have good data has been truncated to zero.  When it is set
  31  * the btrfs file release call will add this inode to the
  32  * ordered operations list so that we make sure to flush out any
  33  * new data the application may have written before commit.
  34  */
  35 #define BTRFS_INODE_ORDERED_DATA_CLOSE          0
  36 #define BTRFS_INODE_ORPHAN_META_RESERVED        1
  37 #define BTRFS_INODE_DUMMY                       2
  38 #define BTRFS_INODE_IN_DEFRAG                   3
  39 #define BTRFS_INODE_DELALLOC_META_RESERVED      4
  40 #define BTRFS_INODE_HAS_ORPHAN_ITEM             5
  41 #define BTRFS_INODE_HAS_ASYNC_EXTENT            6
  42 #define BTRFS_INODE_NEEDS_FULL_SYNC             7
  43 #define BTRFS_INODE_COPY_EVERYTHING             8
  44 #define BTRFS_INODE_IN_DELALLOC_LIST            9
  45 #define BTRFS_INODE_READDIO_NEED_LOCK           10
  46
  47 /* in memory btrfs inode */
  48 struct btrfs_inode {
  49         /* which subvolume this inode belongs to */
  50         struct btrfs_root *root;
  51
  52         /* key used to find this inode on disk.  This is used by the code
  53          * to read in roots of subvolumes
  54          */
  55         struct btrfs_key location;
  56
  57         /* Lock for counters */
  58         spinlock_t lock;
  59
  60         /* the extent_tree has caches of all the extent mappings to disk */
  61         struct extent_map_tree extent_tree;
  62
  63         /* the io_tree does range state (DIRTY, LOCKED etc) */
  64         struct extent_io_tree io_tree;
  65
  66         /* special utility tree used to record which mirrors have already been
  67          * tried when checksums fail for a given block
  68          */
  69         struct extent_io_tree io_failure_tree;
  70
  71         /* held while logging the inode in tree-log.c */
  72         struct mutex log_mutex;
  73
  74         /* held while doing delalloc reservations */
  75         struct mutex delalloc_mutex;
  76
  77         /* used to order data wrt metadata */
  78         struct btrfs_ordered_inode_tree ordered_tree;
  79
  80         /* list of all the delalloc inodes in the FS.  There are times we need
  81          * to write all the delalloc pages to disk, and this list is used
  82          * to walk them all.
  83          */
  84         struct list_head delalloc_inodes;
  85
  86         /*
  87          * list for tracking inodes that must be sent to disk before a
  88          * rename or truncate commit
  89          */
  90         struct list_head ordered_operations;
  91
  92         /* node for the red-black tree that links inodes in subvolume root */
  93         struct rb_node rb_node;
  94
  95         unsigned long runtime_flags;
  96
  97         /* Keep track of who's O_SYNC/fsyncing currently */
  98         atomic_t sync_writers;
  99
 100         /* full 64 bit generation number, struct vfs_inode doesn't have a big
 101          * enough field for this.
 102          */
 103         u64 generation;
 104
 105         /*
 106          * transid of the trans_handle that last modified this inode
 107          */
 108         u64 last_trans;
 109
 110         /*
 111          * log transid when this inode was last modified
 112          */
 113         u64 last_sub_trans;
 114
 115         /*
 116          * transid that last logged this inode
 117          */
 118         u64 logged_trans;
 119
 120         /* total number of bytes pending delalloc, used by stat to calc the
 121          * real block usage of the file
 122          */
 123         u64 delalloc_bytes;
 124
 125         /*
 126          * the size of the file stored in the metadata on disk.  data=ordered
 127          * means the in-memory i_size might be larger than the size on disk
 128          * because not all the blocks are written yet.
 129          */
 130         u64 disk_i_size;
 131
 132         /*
 133          * if this is a directory then index_cnt is the counter for the index
 134          * number for new files that are created
 135          */
 136         u64 index_cnt;
 137
 138         /* the fsync log has some corner cases that mean we have to check
 139          * directories to see if any unlinks have been done before
 140          * the directory was logged.  See tree-log.c for all the
 141          * details
 142          */
 143         u64 last_unlink_trans;
 144
 145         /*
 146          * Number of bytes outstanding that are going to need csums.  This is
 147          * used in ENOSPC accounting.
 148          */
 149         u64 csum_bytes;
 150
 151         /* flags field from the on disk inode */
 152         u32 flags;
 153
 154         /* a local copy of root's last_log_commit */
 155         unsigned long last_log_commit;
 156
 157         /*
 158          * Counters to keep track of the number of extent item's we may use due
 159          * to delalloc and such.  outstanding_extents is the number of extent
 160          * items we think we'll end up using, and reserved_extents is the number
 161          * of extent items we've reserved metadata for.
 162          */
 163         unsigned outstanding_extents;
 164         unsigned reserved_extents;
 165
 166         /*
 167          * always compress this one file
 168          */
 169         unsigned force_compress;
 170
 171         struct btrfs_delayed_node *delayed_node;
 172
 173         struct inode vfs_inode;
 174 };
 175
 176 extern unsigned char btrfs_filetype_table[];
 177
 178 static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
 179 {
 180         return container_of(inode, struct btrfs_inode, vfs_inode);
 181 }
 182
 183 static inline unsigned long btrfs_inode_hash(u64 objectid,
 184                                              const struct btrfs_root *root)
 185 {
 186         u64 h = objectid ^ (root->objectid * GOLDEN_RATIO_PRIME);
 187
 188 #if BITS_PER_LONG == 32
 189         h = (h >> 32) ^ (h & 0xffffffff);
 190 #endif
 191
 192         return (unsigned long)h;
 193 }
 194
 195 static inline void btrfs_insert_inode_hash(struct inode *inode)
 196 {
 197         unsigned long h = btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root);
 198
 199         __insert_inode_hash(inode, h);
 200 }
 201
 202 static inline u64 btrfs_ino(struct inode *inode)
 203 {
 204         u64 ino = BTRFS_I(inode)->location.objectid;
 205
 206         /*
 207          * !ino: btree_inode
 208          * type == BTRFS_ROOT_ITEM_KEY: subvol dir
 209          */
 210         if (!ino || BTRFS_I(inode)->location.type == BTRFS_ROOT_ITEM_KEY)
 211                 ino = inode->i_ino;
 212         return ino;
 213 }
 214
 215 static inline void btrfs_i_size_write(struct inode *inode, u64 size)
 216 {
 217         i_size_write(inode, size);
 218         BTRFS_I(inode)->disk_i_size = size;
 219 }
 220
 221 static inline bool btrfs_is_free_space_inode(struct inode *inode)
 222 {
 223         struct btrfs_root *root = BTRFS_I(inode)->root;
 224
 225         if (root == root->fs_info->tree_root &&
 226             btrfs_ino(inode) != BTRFS_BTREE_INODE_OBJECTID)
 227                 return true;
 228         if (BTRFS_I(inode)->location.objectid == BTRFS_FREE_INO_OBJECTID)
 229                 return true;
 230         return false;
 231 }
 232
 233 static inline int btrfs_inode_in_log(struct inode *inode, u64 generation)
 234 {
 235         if (BTRFS_I(inode)->logged_trans == generation &&
 236             BTRFS_I(inode)->last_sub_trans <=
 237             BTRFS_I(inode)->last_log_commit &&
 238             BTRFS_I(inode)->last_sub_trans <=
 239             BTRFS_I(inode)->root->last_log_commit)
 240                 return 1;
 241         return 0;
 242 }
 243
 244 struct btrfs_dio_private {
 245         struct inode *inode;
 246         u64 logical_offset;
 247         u64 disk_bytenr;
 248         u64 bytes;
 249         void *private;
 250
 251         /* number of bios pending for this dio */
 252         atomic_t pending_bios;
 253
 254         /* IO errors */
 255         int errors;
 256
 257         /* orig_bio is our btrfs_io_bio */
 258         struct bio *orig_bio;
 259
 260         /* dio_bio came from fs/direct-io.c */
 261         struct bio *dio_bio;
 262         u8 csum[0];
 263 };
 264
 265 /*
 266  * Disable DIO read nolock optimization, so new dio readers will be forced
 267  * to grab i_mutex. It is used to avoid the endless truncate due to
 268  * nonlocked dio read.
 269  */
 270 static inline void btrfs_inode_block_unlocked_dio(struct inode *inode)
 271 {
 272         set_bit(BTRFS_INODE_READDIO_NEED_LOCK, &BTRFS_I(inode)->runtime_flags);
 273         smp_mb();
 274 }
 275
 276 static inline void btrfs_inode_resume_unlocked_dio(struct inode *inode)
 277 {
 278         smp_mb__before_clear_bit();
 279         clear_bit(BTRFS_INODE_READDIO_NEED_LOCK,
 280                   &BTRFS_I(inode)->runtime_flags);
 281 }
 282
 283 #endif