LXR linux/fs/btrfs/ordered-data.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_ORDERED_DATA__
  20#define __BTRFS_ORDERED_DATA__
  21
  22/* one of these per inode */
  23struct btrfs_ordered_inode_tree {
  24        struct mutex mutex;
  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 compressed extent */
  72
  73#define BTRFS_ORDERED_PREALLOC 4 /* set when writing to prealloced extent */
  74
  75struct btrfs_ordered_extent {
  76        /* logical offset in the file */
  77        u64 file_offset;
  78
  79        /* disk byte number */
  80        u64 start;
  81
  82        /* ram length of the extent in bytes */
  83        u64 len;
  84
  85        /* extent length on disk */
  86        u64 disk_len;
  87
  88        /* number of bytes that still need writing */
  89        u64 bytes_left;
  90
  91        /* flags (described above) */
  92        unsigned long flags;
  93
  94        /* reference count */
  95        atomic_t refs;
  96
  97        /* the inode we belong to */
  98        struct inode *inode;
  99
 100        /* list of checksums for insertion when the extent io is done */
 101        struct list_head list;
 102
 103        /* used to wait for the BTRFS_ORDERED_COMPLETE bit */
 104        wait_queue_head_t wait;
 105
 106        /* our friendly rbtree entry */
 107        struct rb_node rb_node;
 108
 109        /* a per root list of all the pending ordered extents */
 110        struct list_head root_extent_list;
 111};
 112
 113
 114/*
 115 * calculates the total size you need to allocate for an ordered sum
 116 * structure spanning 'bytes' in the file
 117 */
 118static inline int btrfs_ordered_sum_size(struct btrfs_root *root,
 119                                         unsigned long bytes)
 120{
 121        unsigned long num_sectors = (bytes + root->sectorsize - 1) /
 122                root->sectorsize;
 123        num_sectors++;
 124        return sizeof(struct btrfs_ordered_sum) +
 125                num_sectors * sizeof(struct btrfs_sector_sum);
 126}
 127
 128static inline void
 129btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
 130{
 131        mutex_init(&t->mutex);
 132        t->tree.rb_node = NULL;
 133        t->last = NULL;
 134}
 135
 136int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
 137int btrfs_remove_ordered_extent(struct inode *inode,
 138                                struct btrfs_ordered_extent *entry);
 139int btrfs_dec_test_ordered_pending(struct inode *inode,
 140                                       u64 file_offset, u64 io_size);
 141int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 142                             u64 start, u64 len, u64 disk_len, int tyep);
 143int btrfs_add_ordered_sum(struct inode *inode,
 144                          struct btrfs_ordered_extent *entry,
 145                          struct btrfs_ordered_sum *sum);
 146struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 147                                                         u64 file_offset);
 148void btrfs_start_ordered_extent(struct inode *inode,
 149                                struct btrfs_ordered_extent *entry, int wait);
 150int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
 151struct btrfs_ordered_extent *
 152btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
 153int btrfs_ordered_update_i_size(struct inode *inode,
 154                                struct btrfs_ordered_extent *ordered);
 155int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, u32 *sum);
 156int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only);
 157int btrfs_run_ordered_operations(struct btrfs_root *root, int wait);
 158int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
 159                                struct btrfs_root *root,
 160                                struct inode *inode);
 161#endif
 162