LXR linux/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 */
  23struct btrfs_ordered_inode_tree {
  24        spinlock_t lock;
  25        struct rb_root tree;
  26        struct rb_node *last;
  27};
  28
  29struct btrfs_ordered_sum {
  30        /* bytenr is the start of this extent on disk */
  31        u64 bytenr;
  32
  33        /*
  34         * this is the length in bytes covered by the sums array below.
  35         */
  36        int len;
  37        struct list_head list;
  38        /* last field is a variable length array of csums */
  39        u32 sums[];
  40};
  41
  42/*
  43 * bits for the flags field:
  44 *
  45 * BTRFS_ORDERED_IO_DONE is set when all of the blocks are written.
  46 * It is used to make sure metadata is inserted into the tree only once
  47 * per extent.
  48 *
  49 * BTRFS_ORDERED_COMPLETE is set when the extent is removed from the
  50 * rbtree, just before waking any waiters.  It is used to indicate the
  51 * IO is done and any metadata is inserted into the tree.
  52 */
  53#define BTRFS_ORDERED_IO_DONE 0 /* set when all the pages are written */
  54
  55#define BTRFS_ORDERED_COMPLETE 1 /* set when removed from the tree */
  56
  57#define BTRFS_ORDERED_NOCOW 2 /* set when we want to write in place */
  58
  59#define BTRFS_ORDERED_COMPRESSED 3 /* writing a zlib compressed extent */
  60
  61#define BTRFS_ORDERED_PREALLOC 4 /* set when writing to preallocated extent */
  62
  63#define BTRFS_ORDERED_DIRECT 5 /* set when we're doing DIO with this extent */
  64
  65#define BTRFS_ORDERED_IOERR 6 /* We had an io error when writing this out */
  66
  67#define BTRFS_ORDERED_UPDATED_ISIZE 7 /* indicates whether this ordered extent
  68                                       * has done its due diligence in updating
  69                                       * the isize. */
  70#define BTRFS_ORDERED_LOGGED_CSUM 8 /* We've logged the csums on this ordered
  71                                       ordered extent */
  72#define BTRFS_ORDERED_TRUNCATED 9 /* Set when we have to truncate an extent */
  73
  74#define BTRFS_ORDERED_LOGGED 10 /* Set when we've waited on this ordered extent
  75                                 * in the logging code. */
  76#define BTRFS_ORDERED_PENDING 11 /* We are waiting for this ordered extent to
  77                                  * complete in the current transaction. */
  78#define BTRFS_ORDERED_REGULAR 12 /* Regular IO for COW */
  79
  80struct btrfs_ordered_extent {
  81        /* logical offset in the file */
  82        u64 file_offset;
  83
  84        /* disk byte number */
  85        u64 start;
  86
  87        /* ram length of the extent in bytes */
  88        u64 len;
  89
  90        /* extent length on disk */
  91        u64 disk_len;
  92
  93        /* number of bytes that still need writing */
  94        u64 bytes_left;
  95
  96        /*
  97         * the end of the ordered extent which is behind it but
  98         * didn't update disk_i_size. Please see the comment of
  99         * btrfs_ordered_update_i_size();
 100         */
 101        u64 outstanding_isize;
 102
 103        /*
 104         * If we get truncated we need to adjust the file extent we enter for
 105         * this ordered extent so that we do not expose stale data.
 106         */
 107        u64 truncated_len;
 108
 109        /* flags (described above) */
 110        unsigned long flags;
 111
 112        /* compression algorithm */
 113        int compress_type;
 114
 115        /* reference count */
 116        refcount_t refs;
 117
 118        /* the inode we belong to */
 119        struct inode *inode;
 120
 121        /* list of checksums for insertion when the extent io is done */
 122        struct list_head list;
 123
 124        /* If we need to wait on this to be done */
 125        struct list_head log_list;
 126
 127        /* If the transaction needs to wait on this ordered extent */
 128        struct list_head trans_list;
 129
 130        /* used to wait for the BTRFS_ORDERED_COMPLETE bit */
 131        wait_queue_head_t wait;
 132
 133        /* our friendly rbtree entry */
 134        struct rb_node rb_node;
 135
 136        /* a per root list of all the pending ordered extents */
 137        struct list_head root_extent_list;
 138
 139        struct btrfs_work work;
 140
 141        struct completion completion;
 142        struct btrfs_work flush_work;
 143        struct list_head work_list;
 144};
 145
 146/*
 147 * calculates the total size you need to allocate for an ordered sum
 148 * structure spanning 'bytes' in the file
 149 */
 150static inline int btrfs_ordered_sum_size(struct btrfs_fs_info *fs_info,
 151                                         unsigned long bytes)
 152{
 153        int num_sectors = (int)DIV_ROUND_UP(bytes, fs_info->sectorsize);
 154        return sizeof(struct btrfs_ordered_sum) + num_sectors * sizeof(u32);
 155}
 156
 157static inline void
 158btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
 159{
 160        spin_lock_init(&t->lock);
 161        t->tree = RB_ROOT;
 162        t->last = NULL;
 163}
 164
 165void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
 166void btrfs_remove_ordered_extent(struct inode *inode,
 167                                struct btrfs_ordered_extent *entry);
 168int btrfs_dec_test_ordered_pending(struct inode *inode,
 169                                   struct btrfs_ordered_extent **cached,
 170                                   u64 file_offset, u64 io_size, int uptodate);
 171int btrfs_dec_test_first_ordered_pending(struct inode *inode,
 172                                   struct btrfs_ordered_extent **cached,
 173                                   u64 *file_offset, u64 io_size,
 174                                   int uptodate);
 175int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 176                             u64 start, u64 len, u64 disk_len, int type);
 177int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
 178                                 u64 start, u64 len, u64 disk_len, int type);
 179int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
 180                                      u64 start, u64 len, u64 disk_len,
 181                                      int type, int compress_type);
 182void btrfs_add_ordered_sum(struct inode *inode,
 183                           struct btrfs_ordered_extent *entry,
 184                           struct btrfs_ordered_sum *sum);
 185struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 186                                                         u64 file_offset);
 187void btrfs_start_ordered_extent(struct inode *inode,
 188                                struct btrfs_ordered_extent *entry, int wait);
 189int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
 190struct btrfs_ordered_extent *
 191btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
 192struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 193                struct btrfs_inode *inode,
 194                u64 file_offset,
 195                u64 len);
 196bool btrfs_have_ordered_extents_in_range(struct inode *inode,
 197                                         u64 file_offset,
 198                                         u64 len);
 199int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
 200                                struct btrfs_ordered_extent *ordered);
 201int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
 202                           u32 *sum, int len);
 203u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 204                               const u64 range_start, const u64 range_len);
 205u64 btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 206                              const u64 range_start, const u64 range_len);
 207void btrfs_get_logged_extents(struct btrfs_inode *inode,
 208                              struct list_head *logged_list,
 209                              const loff_t start,
 210                              const loff_t end);
 211void btrfs_put_logged_extents(struct list_head *logged_list);
 212void btrfs_submit_logged_extents(struct list_head *logged_list,
 213                                 struct btrfs_root *log);
 214void btrfs_wait_logged_extents(struct btrfs_trans_handle *trans,
 215                               struct btrfs_root *log, u64 transid);
 216void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid);
 217int __init ordered_data_init(void);
 218void ordered_data_exit(void);
 219#endif
 220