extent_io.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_EXTENT_IO_H__
  20 #define __BTRFS_EXTENT_IO_H__
  21
  22 #if BTRFS_FLAT_INCLUDES
  23 #include "kerncompat.h"
  24 #include "extent-cache.h"
  25 #include "list.h"
  26 #else
  27 #include <btrfs/kerncompat.h>
  28 #include <btrfs/extent-cache.h>
  29 #include <btrfs/list.h>
  30 #endif /* BTRFS_FLAT_INCLUDES */
  31
  32 #define EXTENT_DIRTY            (1U << 0)
  33 #define EXTENT_WRITEBACK        (1U << 1)
  34 #define EXTENT_UPTODATE         (1U << 2)
  35 #define EXTENT_LOCKED           (1U << 3)
  36 #define EXTENT_NEW              (1U << 4)
  37 #define EXTENT_DELALLOC         (1U << 5)
  38 #define EXTENT_DEFRAG           (1U << 6)
  39 #define EXTENT_DEFRAG_DONE      (1U << 7)
  40 #define EXTENT_BUFFER_FILLED    (1U << 8)
  41 #define EXTENT_CSUM             (1U << 9)
  42 #define EXTENT_BAD_TRANSID      (1U << 10)
  43 #define EXTENT_BUFFER_DUMMY     (1U << 11)
  44 #define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
  45
  46 #define BLOCK_GROUP_DATA        (1U << 1)
  47 #define BLOCK_GROUP_METADATA    (1U << 2)
  48 #define BLOCK_GROUP_SYSTEM      (1U << 4)
  49
  50 #define BLOCK_GROUP_DIRTY       (1U)
  51
  52 /*
  53  * The extent buffer bitmap operations are done with byte granularity instead of
  54  * word granularity for two reasons:
  55  * 1. The bitmaps must be little-endian on disk.
  56  * 2. Bitmap items are not guaranteed to be aligned to a word and therefore a
  57  *    single word in a bitmap may straddle two pages in the extent buffer.
  58  */
  59 #define BIT_BYTE(nr) ((nr) / BITS_PER_BYTE)
  60 #define BYTE_MASK ((1 << BITS_PER_BYTE) - 1)
  61 #define BITMAP_FIRST_BYTE_MASK(start) \
  62         ((BYTE_MASK << ((start) & (BITS_PER_BYTE - 1))) & BYTE_MASK)
  63 #define BITMAP_LAST_BYTE_MASK(nbits) \
  64         (BYTE_MASK >> (-(nbits) & (BITS_PER_BYTE - 1)))
  65
  66 static inline int le_test_bit(int nr, const u8 *addr)
  67 {
  68         return 1U & (addr[BIT_BYTE(nr)] >> (nr & (BITS_PER_BYTE-1)));
  69 }
  70
  71 struct btrfs_fs_info;
  72
  73 struct extent_io_tree {
  74         struct cache_tree state;
  75         struct cache_tree cache;
  76         struct list_head lru;
  77         u64 cache_size;
  78         u64 max_cache_size;
  79 };
  80
  81 struct extent_state {
  82         struct cache_extent cache_node;
  83         u64 start;
  84         u64 end;
  85         int refs;
  86         unsigned long state;
  87         u64 xprivate;
  88 };
  89
  90 struct extent_buffer {
  91         struct cache_extent cache_node;
  92         u64 start;
  93         u64 dev_bytenr;
  94         u32 len;
  95         struct extent_io_tree *tree;
  96         struct list_head lru;
  97         struct list_head recow;
  98         int refs;
  99         u32 flags;
 100         int fd;
 101         char data[] __attribute__((aligned(8)));
 102 };
 103
 104 static inline void extent_buffer_get(struct extent_buffer *eb)
 105 {
 106         eb->refs++;
 107 }
 108
 109 void extent_io_tree_init(struct extent_io_tree *tree);
 110 void extent_io_tree_init_cache_max(struct extent_io_tree *tree,
 111                                    u64 max_cache_size);
 112 void extent_io_tree_cleanup(struct extent_io_tree *tree);
 113 int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, int bits);
 114 int clear_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, int bits);
 115 int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
 116                           u64 *start_ret, u64 *end_ret, int bits);
 117 int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,
 118                    int bits, int filled);
 119 int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end);
 120 int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end);
 121 static inline int set_extent_buffer_uptodate(struct extent_buffer *eb)
 122 {
 123         eb->flags |= EXTENT_UPTODATE;
 124         return 0;
 125 }
 126
 127 static inline int clear_extent_buffer_uptodate(struct extent_buffer *eb)
 128 {
 129         eb->flags &= ~EXTENT_UPTODATE;
 130         return 0;
 131 }
 132
 133 static inline int extent_buffer_uptodate(struct extent_buffer *eb)
 134 {
 135         if (!eb || IS_ERR(eb))
 136                 return 0;
 137         if (eb->flags & EXTENT_UPTODATE)
 138                 return 1;
 139         return 0;
 140 }
 141
 142 int set_state_private(struct extent_io_tree *tree, u64 start, u64 xprivate);
 143 int get_state_private(struct extent_io_tree *tree, u64 start, u64 *xprivate);
 144 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
 145                                          u64 bytenr, u32 blocksize);
 146 struct extent_buffer *find_first_extent_buffer(struct extent_io_tree *tree,
 147                                                u64 start);
 148 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
 149                                           u64 bytenr, u32 blocksize);
 150 struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src);
 151 void free_extent_buffer(struct extent_buffer *eb);
 152 void free_extent_buffer_nocache(struct extent_buffer *eb);
 153 int read_extent_from_disk(struct extent_buffer *eb,
 154                           unsigned long offset, unsigned long len);
 155 int write_extent_to_disk(struct extent_buffer *eb);
 156 int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
 157                          unsigned long start, unsigned long len);
 158 void read_extent_buffer(struct extent_buffer *eb, void *dst,
 159                         unsigned long start, unsigned long len);
 160 void write_extent_buffer(struct extent_buffer *eb, const void *src,
 161                          unsigned long start, unsigned long len);
 162 void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
 163                         unsigned long dst_offset, unsigned long src_offset,
 164                         unsigned long len);
 165 void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
 166                            unsigned long src_offset, unsigned long len);
 167 void memset_extent_buffer(struct extent_buffer *eb, char c,
 168                           unsigned long start, unsigned long len);
 169 int extent_buffer_test_bit(struct extent_buffer *eb, unsigned long start,
 170                            unsigned long nr);
 171 int set_extent_buffer_dirty(struct extent_buffer *eb);
 172 int clear_extent_buffer_dirty(struct extent_buffer *eb);
 173 int read_data_from_disk(struct btrfs_fs_info *info, void *buf, u64 offset,
 174                         u64 bytes, int mirror);
 175 int write_data_to_disk(struct btrfs_fs_info *info, void *buf, u64 offset,
 176                        u64 bytes, int mirror);
 177 #endif