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 #define BTRFS_INODE_HAS_PROPS                   11
  47 /*
  48  * The following 3 bits are meant only for the btree inode.
  49  * When any of them is set, it means an error happened while writing an
  50  * extent buffer belonging to:
  51  * 1) a non-log btree
  52  * 2) a log btree and first log sub-transaction
  53  * 3) a log btree and second log sub-transaction
  54  */
  55 #define BTRFS_INODE_BTREE_ERR                   12
  56 #define BTRFS_INODE_BTREE_LOG1_ERR              13
  57 #define BTRFS_INODE_BTREE_LOG2_ERR              14
  58
  59 /* in memory btrfs inode */
  60 struct btrfs_inode {
  61         /* which subvolume this inode belongs to */
  62         struct btrfs_root *root;
  63
  64         /* key used to find this inode on disk.  This is used by the code
  65          * to read in roots of subvolumes
  66          */
  67         struct btrfs_key location;
  68
  69         /*
  70          * Lock for counters and all fields used to determine if the inode is in
  71          * the log or not (last_trans, last_sub_trans, last_log_commit,
  72          * logged_trans).
  73          */
  74         spinlock_t lock;
  75
  76         /* the extent_tree has caches of all the extent mappings to disk */
  77         struct extent_map_tree extent_tree;
  78
  79         /* the io_tree does range state (DIRTY, LOCKED etc) */
  80         struct extent_io_tree io_tree;
  81
  82         /* special utility tree used to record which mirrors have already been
  83          * tried when checksums fail for a given block
  84          */
  85         struct extent_io_tree io_failure_tree;
  86
  87         /* held while logging the inode in tree-log.c */
  88         struct mutex log_mutex;
  89
  90         /* held while doing delalloc reservations */
  91         struct mutex delalloc_mutex;
  92
  93         /* used to order data wrt metadata */
  94         struct btrfs_ordered_inode_tree ordered_tree;
  95
  96         /* list of all the delalloc inodes in the FS.  There are times we need
  97          * to write all the delalloc pages to disk, and this list is used
  98          * to walk them all.
  99          */
 100         struct list_head delalloc_inodes;
 101
 102         /* node for the red-black tree that links inodes in subvolume root */
 103         struct rb_node rb_node;
 104
 105         unsigned long runtime_flags;
 106
 107         /* Keep track of who's O_SYNC/fsyncing currently */
 108         atomic_t sync_writers;
 109
 110         /* full 64 bit generation number, struct vfs_inode doesn't have a big
 111          * enough field for this.
 112          */
 113         u64 generation;
 114
 115         /*
 116          * transid of the trans_handle that last modified this inode
 117          */
 118         u64 last_trans;
 119
 120         /*
 121          * transid that last logged this inode
 122          */
 123         u64 logged_trans;
 124
 125         /*
 126          * log transid when this inode was last modified
 127          */
 128         int last_sub_trans;
 129
 130         /* a local copy of root's last_log_commit */
 131         int last_log_commit;
 132
 133         /* total number of bytes pending delalloc, used by stat to calc the
 134          * real block usage of the file
 135          */
 136         u64 delalloc_bytes;
 137
 138         /*
 139          * total number of bytes pending defrag, used by stat to check whether
 140          * it needs COW.
 141          */
 142         u64 defrag_bytes;
 143
 144         /*
 145          * the size of the file stored in the metadata on disk.  data=ordered
 146          * means the in-memory i_size might be larger than the size on disk
 147          * because not all the blocks are written yet.
 148          */
 149         u64 disk_i_size;
 150
 151         /*
 152          * if this is a directory then index_cnt is the counter for the index
 153          * number for new files that are created
 154          */
 155         u64 index_cnt;
 156
 157         /* Cache the directory index number to speed the dir/file remove */
 158         u64 dir_index;
 159
 160         /* the fsync log has some corner cases that mean we have to check
 161          * directories to see if any unlinks have been done before
 162          * the directory was logged.  See tree-log.c for all the
 163          * details
 164          */
 165         u64 last_unlink_trans;
 166
 167         /*
 168          * Number of bytes outstanding that are going to need csums.  This is
 169          * used in ENOSPC accounting.
 170          */
 171         u64 csum_bytes;
 172
 173         /* flags field from the on disk inode */
 174         u32 flags;
 175
 176         /*
 177          * Counters to keep track of the number of extent item's we may use due
 178          * to delalloc and such.  outstanding_extents is the number of extent
 179          * items we think we'll end up using, and reserved_extents is the number
 180          * of extent items we've reserved metadata for.
 181          */
 182         unsigned outstanding_extents;
 183         unsigned reserved_extents;
 184
 185         /*
 186          * always compress this one file
 187          */
 188         unsigned force_compress;
 189
 190         struct btrfs_delayed_node *delayed_node;
 191
 192         /* File creation time. */
 193         struct timespec i_otime;
 194
 195         struct inode vfs_inode;
 196 };
 197
 198 extern unsigned char btrfs_filetype_table[];
 199
 200 static inline struct btrfs_inode *BTRFS_I(struct inode *inode)
 201 {
 202         return container_of(inode, struct btrfs_inode, vfs_inode);
 203 }
 204
 205 static inline unsigned long btrfs_inode_hash(u64 objectid,
 206                                              const struct btrfs_root *root)
 207 {
 208         u64 h = objectid ^ (root->objectid * GOLDEN_RATIO_PRIME);
 209
 210 #if BITS_PER_LONG == 32
 211         h = (h >> 32) ^ (h & 0xffffffff);
 212 #endif
 213
 214         return (unsigned long)h;
 215 }
 216
 217 static inline void btrfs_insert_inode_hash(struct inode *inode)
 218 {
 219         unsigned long h = btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root);
 220
 221         __insert_inode_hash(inode, h);
 222 }
 223
 224 static inline u64 btrfs_ino(struct inode *inode)
 225 {
 226         u64 ino = BTRFS_I(inode)->location.objectid;
 227
 228         /*
 229          * !ino: btree_inode
 230          * type == BTRFS_ROOT_ITEM_KEY: subvol dir
 231          */
 232         if (!ino || BTRFS_I(inode)->location.type == BTRFS_ROOT_ITEM_KEY)
 233                 ino = inode->i_ino;
 234         return ino;
 235 }
 236
 237 static inline void btrfs_i_size_write(struct inode *inode, u64 size)
 238 {
 239         i_size_write(inode, size);
 240         BTRFS_I(inode)->disk_i_size = size;
 241 }
 242
 243 static inline bool btrfs_is_free_space_inode(struct inode *inode)
 244 {
 245         struct btrfs_root *root = BTRFS_I(inode)->root;
 246
 247         if (root == root->fs_info->tree_root &&
 248             btrfs_ino(inode) != BTRFS_BTREE_INODE_OBJECTID)
 249                 return true;
 250         if (BTRFS_I(inode)->location.objectid == BTRFS_FREE_INO_OBJECTID)
 251                 return true;
 252         return false;
 253 }
 254
 255 static inline int btrfs_inode_in_log(struct inode *inode, u64 generation)
 256 {
 257         int ret = 0;
 258
 259         spin_lock(&BTRFS_I(inode)->lock);
 260         if (BTRFS_I(inode)->logged_trans == generation &&
 261             BTRFS_I(inode)->last_sub_trans <=
 262             BTRFS_I(inode)->last_log_commit &&
 263             BTRFS_I(inode)->last_sub_trans <=
 264             BTRFS_I(inode)->root->last_log_commit) {
 265                 /*
 266                  * After a ranged fsync we might have left some extent maps
 267                  * (that fall outside the fsync's range). So return false
 268                  * here if the list isn't empty, to make sure btrfs_log_inode()
 269                  * will be called and process those extent maps.
 270                  */
 271                 smp_mb();
 272                 if (list_empty(&BTRFS_I(inode)->extent_tree.modified_extents))
 273                         ret = 1;
 274         }
 275         spin_unlock(&BTRFS_I(inode)->lock);
 276         return ret;
 277 }
 278
 279 #define BTRFS_DIO_ORIG_BIO_SUBMITTED    0x1
 280
 281 struct btrfs_dio_private {
 282         struct inode *inode;
 283         unsigned long flags;
 284         u64 logical_offset;
 285         u64 disk_bytenr;
 286         u64 bytes;
 287         void *private;
 288
 289         /* number of bios pending for this dio */
 290         atomic_t pending_bios;
 291
 292         /* IO errors */
 293         int errors;
 294
 295         /* orig_bio is our btrfs_io_bio */
 296         struct bio *orig_bio;
 297
 298         /* dio_bio came from fs/direct-io.c */
 299         struct bio *dio_bio;
 300
 301         /*
 302          * The original bio may be splited to several sub-bios, this is
 303          * done during endio of sub-bios
 304          */
 305         int (*subio_endio)(struct inode *, struct btrfs_io_bio *, int);
 306 };
 307
 308 /*
 309  * Disable DIO read nolock optimization, so new dio readers will be forced
 310  * to grab i_mutex. It is used to avoid the endless truncate due to
 311  * nonlocked dio read.
 312  */
 313 static inline void btrfs_inode_block_unlocked_dio(struct inode *inode)
 314 {
 315         set_bit(BTRFS_INODE_READDIO_NEED_LOCK, &BTRFS_I(inode)->runtime_flags);
 316         smp_mb();
 317 }
 318
 319 static inline void btrfs_inode_resume_unlocked_dio(struct inode *inode)
 320 {
 321         smp_mb__before_atomic();
 322         clear_bit(BTRFS_INODE_READDIO_NEED_LOCK,
 323                   &BTRFS_I(inode)->runtime_flags);
 324 }
 325
 326 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end);
 327
 328 #endif