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 struct btrfs_ordered_extent {
  70         /* logical offset in the file */
  71         u64 file_offset;
  72
  73         /* disk byte number */
  74         u64 start;
  75
  76         /* length of the extent in bytes */
  77         u64 len;
  78
  79         /* flags (described above) */
  80         unsigned long flags;
  81
  82         /* reference count */
  83         atomic_t refs;
  84
  85         /* the inode we belong to */
  86         struct inode *inode;
  87
  88         /* list of checksums for insertion when the extent io is done */
  89         struct list_head list;
  90
  91         /* used to wait for the BTRFS_ORDERED_COMPLETE bit */
  92         wait_queue_head_t wait;
  93
  94         /* our friendly rbtree entry */
  95         struct rb_node rb_node;
  96
  97         /* a per root list of all the pending ordered extents */
  98         struct list_head root_extent_list;
  99 };
 100
 101
 102 /*
 103  * calculates the total size you need to allocate for an ordered sum
 104  * structure spanning 'bytes' in the file
 105  */
 106 static inline int btrfs_ordered_sum_size(struct btrfs_root *root,
 107                                          unsigned long bytes)
 108 {
 109         unsigned long num_sectors = (bytes + root->sectorsize - 1) /
 110                 root->sectorsize;
 111         num_sectors++;
 112         return sizeof(struct btrfs_ordered_sum) +
 113                 num_sectors * sizeof(struct btrfs_sector_sum);
 114 }
 115
 116 static inline void
 117 btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
 118 {
 119         mutex_init(&t->mutex);
 120         t->tree.rb_node = NULL;
 121         t->last = NULL;
 122 }
 123
 124 int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
 125 int btrfs_remove_ordered_extent(struct inode *inode,
 126                                 struct btrfs_ordered_extent *entry);
 127 int btrfs_dec_test_ordered_pending(struct inode *inode,
 128                                        u64 file_offset, u64 io_size);
 129 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 130                              u64 start, u64 len, int nocow);
 131 int btrfs_add_ordered_sum(struct inode *inode,
 132                           struct btrfs_ordered_extent *entry,
 133                           struct btrfs_ordered_sum *sum);
 134 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 135                                                          u64 file_offset);
 136 void btrfs_start_ordered_extent(struct inode *inode,
 137                                 struct btrfs_ordered_extent *entry, int wait);
 138 void btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
 139 struct btrfs_ordered_extent *
 140 btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
 141 int btrfs_ordered_update_i_size(struct inode *inode,
 142                                 struct btrfs_ordered_extent *ordered);
 143 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u32 *sum);
 144 int btrfs_wait_on_page_writeback_range(struct address_space *mapping,
 145                                        pgoff_t start, pgoff_t end);
 146 int btrfs_fdatawrite_range(struct address_space *mapping, loff_t start,
 147                            loff_t end, int sync_mode);
 148 int btrfs_wait_ordered_extents(struct btrfs_root *root, int nocow_only);
 149 #endif