linux/fs/btrfs/ordered-data.h
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   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_ORDERED_DATA__
  20#define __BTRFS_ORDERED_DATA__
  21
  22/* one of these per inode */
  23struct btrfs_ordered_inode_tree {
  24        spinlock_t lock;
  25        struct rb_root tree;
  26        struct rb_node *last;
  27};
  28
  29/*
  30 * these are used to collect checksums done just before bios submission.
  31 * They are attached via a list into the ordered extent, and
  32 * checksum items are inserted into the tree after all the blocks in
  33 * the ordered extent are on disk
  34 */
  35struct btrfs_sector_sum {
  36        /* bytenr on disk */
  37        u64 bytenr;
  38        u32 sum;
  39};
  40
  41struct btrfs_ordered_sum {
  42        /* bytenr is the start of this extent on disk */
  43        u64 bytenr;
  44
  45        /*
  46         * this is the length in bytes covered by the sums array below.
  47         */
  48        unsigned long len;
  49        struct list_head list;
  50        /* last field is a variable length array of btrfs_sector_sums */
  51        struct btrfs_sector_sum sums[];
  52};
  53
  54/*
  55 * bits for the flags field:
  56 *
  57 * BTRFS_ORDERED_IO_DONE is set when all of the blocks are written.
  58 * It is used to make sure metadata is inserted into the tree only once
  59 * per extent.
  60 *
  61 * BTRFS_ORDERED_COMPLETE is set when the extent is removed from the
  62 * rbtree, just before waking any waiters.  It is used to indicate the
  63 * IO is done and any metadata is inserted into the tree.
  64 */
  65#define BTRFS_ORDERED_IO_DONE 0 /* set when all the pages are written */
  66
  67#define BTRFS_ORDERED_COMPLETE 1 /* set when removed from the tree */
  68
  69#define BTRFS_ORDERED_NOCOW 2 /* set when we want to write in place */
  70
  71#define BTRFS_ORDERED_COMPRESSED 3 /* writing a zlib compressed extent */
  72
  73#define BTRFS_ORDERED_PREALLOC 4 /* set when writing to prealloced extent */
  74
  75#define BTRFS_ORDERED_DIRECT 5 /* set when we're doing DIO with this extent */
  76
  77#define BTRFS_ORDERED_IOERR 6 /* We had an io error when writing this out */
  78
  79#define BTRFS_ORDERED_UPDATED_ISIZE 7 /* indicates wether this ordered extent
  80                                       * has done its due diligence in updating
  81                                       * the isize. */
  82
  83struct btrfs_ordered_extent {
  84        /* logical offset in the file */
  85        u64 file_offset;
  86
  87        /* disk byte number */
  88        u64 start;
  89
  90        /* ram length of the extent in bytes */
  91        u64 len;
  92
  93        /* extent length on disk */
  94        u64 disk_len;
  95
  96        /* number of bytes that still need writing */
  97        u64 bytes_left;
  98
  99        /*
 100         * the end of the ordered extent which is behind it but
 101         * didn't update disk_i_size. Please see the comment of
 102         * btrfs_ordered_update_i_size();
 103         */
 104        u64 outstanding_isize;
 105
 106        /* flags (described above) */
 107        unsigned long flags;
 108
 109        /* compression algorithm */
 110        int compress_type;
 111
 112        /* reference count */
 113        atomic_t refs;
 114
 115        /* the inode we belong to */
 116        struct inode *inode;
 117
 118        /* list of checksums for insertion when the extent io is done */
 119        struct list_head list;
 120
 121        /* used to wait for the BTRFS_ORDERED_COMPLETE bit */
 122        wait_queue_head_t wait;
 123
 124        /* our friendly rbtree entry */
 125        struct rb_node rb_node;
 126
 127        /* a per root list of all the pending ordered extents */
 128        struct list_head root_extent_list;
 129
 130        struct btrfs_work work;
 131};
 132
 133
 134/*
 135 * calculates the total size you need to allocate for an ordered sum
 136 * structure spanning 'bytes' in the file
 137 */
 138static inline int btrfs_ordered_sum_size(struct btrfs_root *root,
 139                                         unsigned long bytes)
 140{
 141        unsigned long num_sectors = (bytes + root->sectorsize - 1) /
 142                root->sectorsize;
 143        num_sectors++;
 144        return sizeof(struct btrfs_ordered_sum) +
 145                num_sectors * sizeof(struct btrfs_sector_sum);
 146}
 147
 148static inline void
 149btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
 150{
 151        spin_lock_init(&t->lock);
 152        t->tree = RB_ROOT;
 153        t->last = NULL;
 154}
 155
 156void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
 157void btrfs_remove_ordered_extent(struct inode *inode,
 158                                struct btrfs_ordered_extent *entry);
 159int btrfs_dec_test_ordered_pending(struct inode *inode,
 160                                   struct btrfs_ordered_extent **cached,
 161                                   u64 file_offset, u64 io_size, int uptodate);
 162int btrfs_dec_test_first_ordered_pending(struct inode *inode,
 163                                   struct btrfs_ordered_extent **cached,
 164                                   u64 *file_offset, u64 io_size,
 165                                   int uptodate);
 166int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 167                             u64 start, u64 len, u64 disk_len, int type);
 168int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
 169                                 u64 start, u64 len, u64 disk_len, int type);
 170int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
 171                                      u64 start, u64 len, u64 disk_len,
 172                                      int type, int compress_type);
 173void btrfs_add_ordered_sum(struct inode *inode,
 174                           struct btrfs_ordered_extent *entry,
 175                           struct btrfs_ordered_sum *sum);
 176struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 177                                                         u64 file_offset);
 178void btrfs_start_ordered_extent(struct inode *inode,
 179                                struct btrfs_ordered_extent *entry, int wait);
 180void btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
 181struct btrfs_ordered_extent *
 182btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
 183struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
 184                                                        u64 file_offset,
 185                                                        u64 len);
 186int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
 187                                struct btrfs_ordered_extent *ordered);
 188int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, u32 *sum);
 189void btrfs_run_ordered_operations(struct btrfs_root *root, int wait);
 190void btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
 191                                 struct btrfs_root *root,
 192                                 struct inode *inode);
 193void btrfs_wait_ordered_extents(struct btrfs_root *root, int delay_iput);
 194int __init ordered_data_init(void);
 195void ordered_data_exit(void);
 196#endif
 197
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