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 prealloced 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
  74struct btrfs_ordered_extent {
  75        /* logical offset in the file */
  76        u64 file_offset;
  77
  78        /* disk byte number */
  79        u64 start;
  80
  81        /* ram length of the extent in bytes */
  82        u64 len;
  83
  84        /* extent length on disk */
  85        u64 disk_len;
  86
  87        /* number of bytes that still need writing */
  88        u64 bytes_left;
  89
  90        /* number of bytes that still need csumming */
  91        u64 csum_bytes_left;
  92
  93        /*
  94         * the end of the ordered extent which is behind it but
  95         * didn't update disk_i_size. Please see the comment of
  96         * btrfs_ordered_update_i_size();
  97         */
  98        u64 outstanding_isize;
  99
 100        /*
 101         * If we get truncated we need to adjust the file extent we enter for
 102         * this ordered extent so that we do not expose stale data.
 103         */
 104        u64 truncated_len;
 105
 106        /* flags (described above) */
 107        unsigned long flags;
 108
 109        /* compression algorithm */
 110        int compress_type;
 111
 112        /* reference count */
 113        atomic_t refs;
 114
 115        /* the inode we belong to */
 116        struct inode *inode;
 117
 118        /* list of checksums for insertion when the extent io is done */
 119        struct list_head list;
 120
 121        /* If we need to wait on this to be done */
 122        struct list_head log_list;
 123
 124        /* used to wait for the BTRFS_ORDERED_COMPLETE bit */
 125        wait_queue_head_t wait;
 126
 127        /* our friendly rbtree entry */
 128        struct rb_node rb_node;
 129
 130        /* a per root list of all the pending ordered extents */
 131        struct list_head root_extent_list;
 132
 133        struct btrfs_work work;
 134
 135        struct completion completion;
 136        struct btrfs_work flush_work;
 137        struct list_head work_list;
 138};
 139
 140/*
 141 * calculates the total size you need to allocate for an ordered sum
 142 * structure spanning 'bytes' in the file
 143 */
 144static inline int btrfs_ordered_sum_size(struct btrfs_root *root,
 145                                         unsigned long bytes)
 146{
 147        int num_sectors = (int)DIV_ROUND_UP(bytes, root->sectorsize);
 148        return sizeof(struct btrfs_ordered_sum) + num_sectors * sizeof(u32);
 149}
 150
 151static inline void
 152btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
 153{
 154        spin_lock_init(&t->lock);
 155        t->tree = RB_ROOT;
 156        t->last = NULL;
 157}
 158
 159void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
 160void btrfs_remove_ordered_extent(struct inode *inode,
 161                                struct btrfs_ordered_extent *entry);
 162int btrfs_dec_test_ordered_pending(struct inode *inode,
 163                                   struct btrfs_ordered_extent **cached,
 164                                   u64 file_offset, u64 io_size, int uptodate);
 165int btrfs_dec_test_first_ordered_pending(struct inode *inode,
 166                                   struct btrfs_ordered_extent **cached,
 167                                   u64 *file_offset, u64 io_size,
 168                                   int uptodate);
 169int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 170                             u64 start, u64 len, u64 disk_len, int type);
 171int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
 172                                 u64 start, u64 len, u64 disk_len, int type);
 173int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
 174                                      u64 start, u64 len, u64 disk_len,
 175                                      int type, int compress_type);
 176void btrfs_add_ordered_sum(struct inode *inode,
 177                           struct btrfs_ordered_extent *entry,
 178                           struct btrfs_ordered_sum *sum);
 179struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 180                                                         u64 file_offset);
 181void btrfs_start_ordered_extent(struct inode *inode,
 182                                struct btrfs_ordered_extent *entry, int wait);
 183void btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
 184struct btrfs_ordered_extent *
 185btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
 186struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
 187                                                        u64 file_offset,
 188                                                        u64 len);
 189int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
 190                                struct btrfs_ordered_extent *ordered);
 191int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
 192                           u32 *sum, int len);
 193int btrfs_run_ordered_operations(struct btrfs_trans_handle *trans,
 194                                 struct btrfs_root *root, int wait);
 195void btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
 196                                 struct btrfs_root *root,
 197                                 struct inode *inode);
 198void btrfs_wait_ordered_extents(struct btrfs_root *root);
 199void btrfs_wait_all_ordered_extents(struct btrfs_fs_info *fs_info);
 200void btrfs_get_logged_extents(struct btrfs_root *log, struct inode *inode);
 201void btrfs_wait_logged_extents(struct btrfs_root *log, u64 transid);
 202void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid);
 203int __init ordered_data_init(void);
 204void ordered_data_exit(void);
 205#endif
 206