LXR linux/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 */
  10struct btrfs_ordered_inode_tree {
  11        spinlock_t lock;
  12        struct rb_root tree;
  13        struct rb_node *last;
  14};
  15
  16struct 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 */
  40enum {
  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        /* Set when we have to truncate an extent */
  56        BTRFS_ORDERED_TRUNCATED,
  57        /* Regular IO for COW */
  58        BTRFS_ORDERED_REGULAR,
  59};
  60
  61struct btrfs_ordered_extent {
  62        /* logical offset in the file */
  63        u64 file_offset;
  64
  65        /*
  66         * These fields directly correspond to the same fields in
  67         * btrfs_file_extent_item.
  68         */
  69        u64 disk_bytenr;
  70        u64 num_bytes;
  71        u64 disk_num_bytes;
  72
  73        /* number of bytes that still need writing */
  74        u64 bytes_left;
  75
  76        /*
  77         * the end of the ordered extent which is behind it but
  78         * didn't update disk_i_size. Please see the comment of
  79         * btrfs_ordered_update_i_size();
  80         */
  81        u64 outstanding_isize;
  82
  83        /*
  84         * If we get truncated we need to adjust the file extent we enter for
  85         * this ordered extent so that we do not expose stale data.
  86         */
  87        u64 truncated_len;
  88
  89        /* flags (described above) */
  90        unsigned long flags;
  91
  92        /* compression algorithm */
  93        int compress_type;
  94
  95        /* reference count */
  96        refcount_t refs;
  97
  98        /* the inode we belong to */
  99        struct inode *inode;
 100
 101        /* list of checksums for insertion when the extent io is done */
 102        struct list_head list;
 103
 104        /* If we need to wait on this to be done */
 105        struct list_head log_list;
 106
 107        /* If the transaction needs to wait on this ordered extent */
 108        struct list_head trans_list;
 109
 110        /* used to wait for the BTRFS_ORDERED_COMPLETE bit */
 111        wait_queue_head_t wait;
 112
 113        /* our friendly rbtree entry */
 114        struct rb_node rb_node;
 115
 116        /* a per root list of all the pending ordered extents */
 117        struct list_head root_extent_list;
 118
 119        struct btrfs_work work;
 120
 121        struct completion completion;
 122        struct btrfs_work flush_work;
 123        struct list_head work_list;
 124};
 125
 126/*
 127 * calculates the total size you need to allocate for an ordered sum
 128 * structure spanning 'bytes' in the file
 129 */
 130static inline int btrfs_ordered_sum_size(struct btrfs_fs_info *fs_info,
 131                                         unsigned long bytes)
 132{
 133        int num_sectors = (int)DIV_ROUND_UP(bytes, fs_info->sectorsize);
 134        int csum_size = btrfs_super_csum_size(fs_info->super_copy);
 135
 136        return sizeof(struct btrfs_ordered_sum) + num_sectors * csum_size;
 137}
 138
 139static inline void
 140btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
 141{
 142        spin_lock_init(&t->lock);
 143        t->tree = RB_ROOT;
 144        t->last = NULL;
 145}
 146
 147void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
 148void btrfs_remove_ordered_extent(struct inode *inode,
 149                                struct btrfs_ordered_extent *entry);
 150int btrfs_dec_test_ordered_pending(struct inode *inode,
 151                                   struct btrfs_ordered_extent **cached,
 152                                   u64 file_offset, u64 io_size, int uptodate);
 153int btrfs_dec_test_first_ordered_pending(struct inode *inode,
 154                                   struct btrfs_ordered_extent **cached,
 155                                   u64 *file_offset, u64 io_size,
 156                                   int uptodate);
 157int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 158                             u64 disk_bytenr, u64 num_bytes, u64 disk_num_bytes,
 159                             int type);
 160int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
 161                                 u64 disk_bytenr, u64 num_bytes,
 162                                 u64 disk_num_bytes, int type);
 163int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
 164                                      u64 disk_bytenr, u64 num_bytes,
 165                                      u64 disk_num_bytes, int type,
 166                                      int compress_type);
 167void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 168                           struct btrfs_ordered_sum *sum);
 169struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 170                                                         u64 file_offset);
 171void btrfs_start_ordered_extent(struct inode *inode,
 172                                struct btrfs_ordered_extent *entry, int wait);
 173int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
 174struct btrfs_ordered_extent *
 175btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
 176struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 177                struct btrfs_inode *inode,
 178                u64 file_offset,
 179                u64 len);
 180int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
 181                           u8 *sum, int len);
 182u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 183                               const u64 range_start, const u64 range_len);
 184void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 185                              const u64 range_start, const u64 range_len);
 186void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
 187                                        u64 end,
 188                                        struct extent_state **cached_state);
 189int __init ordered_data_init(void);
 190void __cold ordered_data_exit(void);
 191
 192#endif
 193