fs/btrfs/ordered-data.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #ifndef BTRFS_ORDERED_DATA_H
   7 #define BTRFS_ORDERED_DATA_H
   8
   9 /* one of these per inode */
  10 struct btrfs_ordered_inode_tree {
  11         spinlock_t lock;
  12         struct rb_root tree;
  13         struct rb_node *last;
  14 };
  15
  16 struct btrfs_ordered_sum {
  17         /* bytenr is the start of this extent on disk */
  18         u64 bytenr;
  19
  20         /*
  21          * this is the length in bytes covered by the sums array below.
  22          */
  23         int len;
  24         struct list_head list;
  25         /* last field is a variable length array of csums */
  26         u8 sums[];
  27 };
  28
  29 /*
  30  * bits for the flags field:
  31  *
  32  * BTRFS_ORDERED_IO_DONE is set when all of the blocks are written.
  33  * It is used to make sure metadata is inserted into the tree only once
  34  * per extent.
  35  *
  36  * BTRFS_ORDERED_COMPLETE is set when the extent is removed from the
  37  * rbtree, just before waking any waiters.  It is used to indicate the
  38  * IO is done and any metadata is inserted into the tree.
  39  */
  40 enum {
  41         /* set when all the pages are written */
  42         BTRFS_ORDERED_IO_DONE,
  43         /* set when removed from the tree */
  44         BTRFS_ORDERED_COMPLETE,
  45         /* set when we want to write in place */
  46         BTRFS_ORDERED_NOCOW,
  47         /* writing a zlib compressed extent */
  48         BTRFS_ORDERED_COMPRESSED,
  49         /* set when writing to preallocated extent */
  50         BTRFS_ORDERED_PREALLOC,
  51         /* set when we're doing DIO with this extent */
  52         BTRFS_ORDERED_DIRECT,
  53         /* We had an io error when writing this out */
  54         BTRFS_ORDERED_IOERR,
  55         /*
  56          * indicates whether this ordered extent has done its due diligence in
  57          * updating the isize
  58          */
  59         BTRFS_ORDERED_UPDATED_ISIZE,
  60         /* Set when we have to truncate an extent */
  61         BTRFS_ORDERED_TRUNCATED,
  62         /* Regular IO for COW */
  63         BTRFS_ORDERED_REGULAR,
  64 };
  65
  66 struct btrfs_ordered_extent {
  67         /* logical offset in the file */
  68         u64 file_offset;
  69
  70         /* disk byte number */
  71         u64 start;
  72
  73         /* ram length of the extent in bytes */
  74         u64 len;
  75
  76         /* extent length on disk */
  77         u64 disk_len;
  78
  79         /* number of bytes that still need writing */
  80         u64 bytes_left;
  81
  82         /*
  83          * the end of the ordered extent which is behind it but
  84          * didn't update disk_i_size. Please see the comment of
  85          * btrfs_ordered_update_i_size();
  86          */
  87         u64 outstanding_isize;
  88
  89         /*
  90          * If we get truncated we need to adjust the file extent we enter for
  91          * this ordered extent so that we do not expose stale data.
  92          */
  93         u64 truncated_len;
  94
  95         /* flags (described above) */
  96         unsigned long flags;
  97
  98         /* compression algorithm */
  99         int compress_type;
 100
 101         /* reference count */
 102         refcount_t refs;
 103
 104         /* the inode we belong to */
 105         struct inode *inode;
 106
 107         /* list of checksums for insertion when the extent io is done */
 108         struct list_head list;
 109
 110         /* If we need to wait on this to be done */
 111         struct list_head log_list;
 112
 113         /* If the transaction needs to wait on this ordered extent */
 114         struct list_head trans_list;
 115
 116         /* used to wait for the BTRFS_ORDERED_COMPLETE bit */
 117         wait_queue_head_t wait;
 118
 119         /* our friendly rbtree entry */
 120         struct rb_node rb_node;
 121
 122         /* a per root list of all the pending ordered extents */
 123         struct list_head root_extent_list;
 124
 125         struct btrfs_work work;
 126
 127         struct completion completion;
 128         struct btrfs_work flush_work;
 129         struct list_head work_list;
 130 };
 131
 132 /*
 133  * calculates the total size you need to allocate for an ordered sum
 134  * structure spanning 'bytes' in the file
 135  */
 136 static inline int btrfs_ordered_sum_size(struct btrfs_fs_info *fs_info,
 137                                          unsigned long bytes)
 138 {
 139         int num_sectors = (int)DIV_ROUND_UP(bytes, fs_info->sectorsize);
 140         int csum_size = btrfs_super_csum_size(fs_info->super_copy);
 141
 142         return sizeof(struct btrfs_ordered_sum) + num_sectors * csum_size;
 143 }
 144
 145 static inline void
 146 btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
 147 {
 148         spin_lock_init(&t->lock);
 149         t->tree = RB_ROOT;
 150         t->last = NULL;
 151 }
 152
 153 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
 154 void btrfs_remove_ordered_extent(struct inode *inode,
 155                                 struct btrfs_ordered_extent *entry);
 156 int btrfs_dec_test_ordered_pending(struct inode *inode,
 157                                    struct btrfs_ordered_extent **cached,
 158                                    u64 file_offset, u64 io_size, int uptodate);
 159 int btrfs_dec_test_first_ordered_pending(struct inode *inode,
 160                                    struct btrfs_ordered_extent **cached,
 161                                    u64 *file_offset, u64 io_size,
 162                                    int uptodate);
 163 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 164                              u64 start, u64 len, u64 disk_len, int type);
 165 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
 166                                  u64 start, u64 len, u64 disk_len, int type);
 167 int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
 168                                       u64 start, u64 len, u64 disk_len,
 169                                       int type, int compress_type);
 170 void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 171                            struct btrfs_ordered_sum *sum);
 172 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 173                                                          u64 file_offset);
 174 void btrfs_start_ordered_extent(struct inode *inode,
 175                                 struct btrfs_ordered_extent *entry, int wait);
 176 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
 177 struct btrfs_ordered_extent *
 178 btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
 179 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 180                 struct btrfs_inode *inode,
 181                 u64 file_offset,
 182                 u64 len);
 183 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
 184                                 struct btrfs_ordered_extent *ordered);
 185 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
 186                            u8 *sum, int len);
 187 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 188                                const u64 range_start, const u64 range_len);
 189 void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 190                               const u64 range_start, const u64 range_len);
 191 void btrfs_lock_and_flush_ordered_range(struct extent_io_tree *tree,
 192                                         struct btrfs_inode *inode, u64 start,
 193                                         u64 end,
 194                                         struct extent_state **cached_state);
 195 int __init ordered_data_init(void);
 196 void __cold ordered_data_exit(void);
 197
 198 #endif