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
  74#define BTRFS_ORDERED_LOGGED 10 /* Set when we've waited on this ordered extent
  75                                 * in the logging code. */
  76struct btrfs_ordered_extent {
  77        /* logical offset in the file */
  78        u64 file_offset;
  79
  80        /* disk byte number */
  81        u64 start;
  82
  83        /* ram length of the extent in bytes */
  84        u64 len;
  85
  86        /* extent length on disk */
  87        u64 disk_len;
  88
  89        /* number of bytes that still need writing */
  90        u64 bytes_left;
  91
  92        /* number of bytes that still need csumming */
  93        u64 csum_bytes_left;
  94
  95        /*
  96         * the end of the ordered extent which is behind it but
  97         * didn't update disk_i_size. Please see the comment of
  98         * btrfs_ordered_update_i_size();
  99         */
 100        u64 outstanding_isize;
 101
 102        /*
 103         * If we get truncated we need to adjust the file extent we enter for
 104         * this ordered extent so that we do not expose stale data.
 105         */
 106        u64 truncated_len;
 107
 108        /* flags (described above) */
 109        unsigned long flags;
 110
 111        /* compression algorithm */
 112        int compress_type;
 113
 114        /* reference count */
 115        atomic_t refs;
 116
 117        /* the inode we belong to */
 118        struct inode *inode;
 119
 120        /* list of checksums for insertion when the extent io is done */
 121        struct list_head list;
 122
 123        /* If we need to wait on this to be done */
 124        struct list_head log_list;
 125
 126        /* If the transaction needs to wait on this ordered extent */
 127        struct list_head trans_list;
 128
 129        /* used to wait for the BTRFS_ORDERED_COMPLETE bit */
 130        wait_queue_head_t wait;
 131
 132        /* our friendly rbtree entry */
 133        struct rb_node rb_node;
 134
 135        /* a per root list of all the pending ordered extents */
 136        struct list_head root_extent_list;
 137
 138        struct btrfs_work work;
 139
 140        struct completion completion;
 141        struct btrfs_work flush_work;
 142        struct list_head work_list;
 143};
 144
 145/*
 146 * calculates the total size you need to allocate for an ordered sum
 147 * structure spanning 'bytes' in the file
 148 */
 149static inline int btrfs_ordered_sum_size(struct btrfs_root *root,
 150                                         unsigned long bytes)
 151{
 152        int num_sectors = (int)DIV_ROUND_UP(bytes, root->sectorsize);
 153        return sizeof(struct btrfs_ordered_sum) + num_sectors * sizeof(u32);
 154}
 155
 156static inline void
 157btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
 158{
 159        spin_lock_init(&t->lock);
 160        t->tree = RB_ROOT;
 161        t->last = NULL;
 162}
 163
 164void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
 165void btrfs_remove_ordered_extent(struct inode *inode,
 166                                struct btrfs_ordered_extent *entry);
 167int btrfs_dec_test_ordered_pending(struct inode *inode,
 168                                   struct btrfs_ordered_extent **cached,
 169                                   u64 file_offset, u64 io_size, int uptodate);
 170int btrfs_dec_test_first_ordered_pending(struct inode *inode,
 171                                   struct btrfs_ordered_extent **cached,
 172                                   u64 *file_offset, u64 io_size,
 173                                   int uptodate);
 174int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 175                             u64 start, u64 len, u64 disk_len, int type);
 176int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
 177                                 u64 start, u64 len, u64 disk_len, int type);
 178int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
 179                                      u64 start, u64 len, u64 disk_len,
 180                                      int type, int compress_type);
 181void btrfs_add_ordered_sum(struct inode *inode,
 182                           struct btrfs_ordered_extent *entry,
 183                           struct btrfs_ordered_sum *sum);
 184struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 185                                                         u64 file_offset);
 186void btrfs_start_ordered_extent(struct inode *inode,
 187                                struct btrfs_ordered_extent *entry, int wait);
 188int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
 189struct btrfs_ordered_extent *
 190btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
 191struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
 192                                                        u64 file_offset,
 193                                                        u64 len);
 194int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
 195                                struct btrfs_ordered_extent *ordered);
 196int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
 197                           u32 *sum, int len);
 198int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr);
 199void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, int nr);
 200void btrfs_get_logged_extents(struct inode *inode,
 201                              struct list_head *logged_list,
 202                              const loff_t start,
 203                              const loff_t end);
 204void btrfs_put_logged_extents(struct list_head *logged_list);
 205void btrfs_submit_logged_extents(struct list_head *logged_list,
 206                                 struct btrfs_root *log);
 207void btrfs_wait_logged_extents(struct btrfs_trans_handle *trans,
 208                               struct btrfs_root *log, u64 transid);
 209void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid);
 210int __init ordered_data_init(void);
 211void ordered_data_exit(void);
 212#endif
 213