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 */
  23 struct 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  */
  35 struct btrfs_sector_sum {
  36         /* bytenr on disk */
  37         u64 bytenr;
  38         u32 sum;
  39 };
  40
  41 struct 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
  75 struct 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  */
 118 static 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
 128 static inline void
 129 btrfs_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
 136 int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
 137 int btrfs_remove_ordered_extent(struct inode *inode,
 138                                 struct btrfs_ordered_extent *entry);
 139 int btrfs_dec_test_ordered_pending(struct inode *inode,
 140                                        u64 file_offset, u64 io_size);
 141 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 142                              u64 start, u64 len, u64 disk_len, int tyep);
 143 int btrfs_add_ordered_sum(struct inode *inode,
 144                           struct btrfs_ordered_extent *entry,
 145                           struct btrfs_ordered_sum *sum);
 146 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 147                                                          u64 file_offset);
 148 void btrfs_start_ordered_extent(struct inode *inode,
 149                                 struct btrfs_ordered_extent *entry, int wait);
 150 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
 151 struct btrfs_ordered_extent *
 152 btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
 153 int btrfs_ordered_update_i_size(struct inode *inode,
 154                                 struct btrfs_ordered_extent *ordered);
 155 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, u32 *sum);
 156 int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only);
 157 int btrfs_run_ordered_operations(struct btrfs_root *root, int wait);
 158 int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
 159                                 struct btrfs_root *root,
 160                                 struct inode *inode);
 161 #endif