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         u64 offset;
  37         u32 sum;
  38 };
  39
  40 struct btrfs_ordered_sum {
  41         u64 file_offset;
  42         /*
  43          * this is the length in bytes covered by the sums array below.
  44          * But, the sums array may not be contiguous in the file.
  45          */
  46         unsigned long len;
  47         struct list_head list;
  48         /* last field is a variable length array of btrfs_sector_sums */
  49         struct btrfs_sector_sum sums[];
  50 };
  51
  52 /*
  53  * bits for the flags field:
  54  *
  55  * BTRFS_ORDERED_IO_DONE is set when all of the blocks are written.
  56  * It is used to make sure metadata is inserted into the tree only once
  57  * per extent.
  58  *
  59  * BTRFS_ORDERED_COMPLETE is set when the extent is removed from the
  60  * rbtree, just before waking any waiters.  It is used to indicate the
  61  * IO is done and any metadata is inserted into the tree.
  62  */
  63 #define BTRFS_ORDERED_IO_DONE 0 /* set when all the pages are written */
  64
  65 #define BTRFS_ORDERED_COMPLETE 1 /* set when removed from the tree */
  66
  67 #define BTRFS_ORDERED_NOCOW 2 /* set when we want to write in place */
  68
  69 #define BTRFS_ORDERED_COMPRESSED 3 /* writing a compressed extent */
  70
  71 struct btrfs_ordered_extent {
  72         /* logical offset in the file */
  73         u64 file_offset;
  74
  75         /* disk byte number */
  76         u64 start;
  77
  78         /* ram length of the extent in bytes */
  79         u64 len;
  80
  81         /* extent length on disk */
  82         u64 disk_len;
  83
  84         /* flags (described above) */
  85         unsigned long flags;
  86
  87         /* reference count */
  88         atomic_t refs;
  89
  90         /* the inode we belong to */
  91         struct inode *inode;
  92
  93         /* list of checksums for insertion when the extent io is done */
  94         struct list_head list;
  95
  96         /* used to wait for the BTRFS_ORDERED_COMPLETE bit */
  97         wait_queue_head_t wait;
  98
  99         /* our friendly rbtree entry */
 100         struct rb_node rb_node;
 101
 102         /* a per root list of all the pending ordered extents */
 103         struct list_head root_extent_list;
 104 };
 105
 106
 107 /*
 108  * calculates the total size you need to allocate for an ordered sum
 109  * structure spanning 'bytes' in the file
 110  */
 111 static inline int btrfs_ordered_sum_size(struct btrfs_root *root,
 112                                          unsigned long bytes)
 113 {
 114         unsigned long num_sectors = (bytes + root->sectorsize - 1) /
 115                 root->sectorsize;
 116         num_sectors++;
 117         return sizeof(struct btrfs_ordered_sum) +
 118                 num_sectors * sizeof(struct btrfs_sector_sum);
 119 }
 120
 121 static inline void
 122 btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
 123 {
 124         mutex_init(&t->mutex);
 125         t->tree.rb_node = NULL;
 126         t->last = NULL;
 127 }
 128
 129 int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
 130 int btrfs_remove_ordered_extent(struct inode *inode,
 131                                 struct btrfs_ordered_extent *entry);
 132 int btrfs_dec_test_ordered_pending(struct inode *inode,
 133                                        u64 file_offset, u64 io_size);
 134 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 135                              u64 start, u64 len, u64 disk_len, int nocow,
 136                              int compressed);
 137 int btrfs_add_ordered_sum(struct inode *inode,
 138                           struct btrfs_ordered_extent *entry,
 139                           struct btrfs_ordered_sum *sum);
 140 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 141                                                          u64 file_offset);
 142 void btrfs_start_ordered_extent(struct inode *inode,
 143                                 struct btrfs_ordered_extent *entry, int wait);
 144 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
 145 struct btrfs_ordered_extent *
 146 btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
 147 int btrfs_ordered_update_i_size(struct inode *inode,
 148                                 struct btrfs_ordered_extent *ordered);
 149 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u32 *sum);
 150 int btrfs_wait_on_page_writeback_range(struct address_space *mapping,
 151                                        pgoff_t start, pgoff_t end);
 152 int btrfs_fdatawrite_range(struct address_space *mapping, loff_t start,
 153                            loff_t end, int sync_mode);
 154 int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only);
 155 #endif