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ordered-data.h
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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 */
25  struct rb_root tree;
26  struct rb_node *last;
27 };
28 
29 /*
30  * these are used to collect checksums done just before bios submission.
31  * They are attached via a list into the ordered extent, and
32  * checksum items are inserted into the tree after all the blocks in
33  * the ordered extent are on disk
34  */
36  /* bytenr on disk */
39 };
40 
42  /* bytenr is the start of this extent on disk */
44 
45  /*
46  * this is the length in bytes covered by the sums array below.
47  */
48  unsigned long len;
49  struct list_head list;
50  /* last field is a variable length array of btrfs_sector_sums */
52 };
53 
54 /*
55  * bits for the flags field:
56  *
57  * BTRFS_ORDERED_IO_DONE is set when all of the blocks are written.
58  * It is used to make sure metadata is inserted into the tree only once
59  * per extent.
60  *
61  * BTRFS_ORDERED_COMPLETE is set when the extent is removed from the
62  * rbtree, just before waking any waiters. It is used to indicate the
63  * IO is done and any metadata is inserted into the tree.
64  */
65 #define BTRFS_ORDERED_IO_DONE 0 /* set when all the pages are written */
66 
67 #define BTRFS_ORDERED_COMPLETE 1 /* set when removed from the tree */
68 
69 #define BTRFS_ORDERED_NOCOW 2 /* set when we want to write in place */
70 
71 #define BTRFS_ORDERED_COMPRESSED 3 /* writing a zlib compressed extent */
72 
73 #define BTRFS_ORDERED_PREALLOC 4 /* set when writing to prealloced extent */
74 
75 #define BTRFS_ORDERED_DIRECT 5 /* set when we're doing DIO with this extent */
76 
77 #define BTRFS_ORDERED_IOERR 6 /* We had an io error when writing this out */
78 
79 #define BTRFS_ORDERED_UPDATED_ISIZE 7 /* indicates wether this ordered extent
80  * has done its due diligence in updating
81  * the isize. */
82 
84  /* logical offset in the file */
86 
87  /* disk byte number */
88  u64 start;
89 
90  /* ram length of the extent in bytes */
91  u64 len;
92 
93  /* extent length on disk */
94  u64 disk_len;
95 
96  /* number of bytes that still need writing */
98 
99  /*
100  * the end of the ordered extent which is behind it but
101  * didn't update disk_i_size. Please see the comment of
102  * btrfs_ordered_update_i_size();
103  */
106  /* flags (described above) */
107  unsigned long flags;
109  /* compression algorithm */
110  int compress_type;
112  /* reference count */
113  atomic_t refs;
115  /* the inode we belong to */
116  struct inode *inode;
118  /* list of checksums for insertion when the extent io is done */
119  struct list_head list;
121  /* used to wait for the BTRFS_ORDERED_COMPLETE bit */
124  /* our friendly rbtree entry */
125  struct rb_node rb_node;
127  /* a per root list of all the pending ordered extents */
129 
130  struct btrfs_work work;
131 };
132 
133 
134 /*
135  * calculates the total size you need to allocate for an ordered sum
136  * structure spanning 'bytes' in the file
137  */
138 static inline int btrfs_ordered_sum_size(struct btrfs_root *root,
139  unsigned long bytes)
140 {
141  unsigned long num_sectors = (bytes + root->sectorsize - 1) /
142  root->sectorsize;
143  num_sectors++;
144  return sizeof(struct btrfs_ordered_sum) +
145  num_sectors * sizeof(struct btrfs_sector_sum);
146 }
147 
148 static inline void
149 btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
150 {
151  spin_lock_init(&t->lock);
152  t->tree = RB_ROOT;
153  t->last = NULL;
154 }
155 
158  struct btrfs_ordered_extent *entry);
160  struct btrfs_ordered_extent **cached,
161  u64 file_offset, u64 io_size, int uptodate);
163  struct btrfs_ordered_extent **cached,
164  u64 *file_offset, u64 io_size,
165  int uptodate);
167  u64 start, u64 len, u64 disk_len, int type);
169  u64 start, u64 len, u64 disk_len, int type);
171  u64 start, u64 len, u64 disk_len,
172  int type, int compress_type);
173 void btrfs_add_ordered_sum(struct inode *inode,
174  struct btrfs_ordered_extent *entry,
175  struct btrfs_ordered_sum *sum);
177  u64 file_offset);
179  struct btrfs_ordered_extent *entry, int wait);
181 struct btrfs_ordered_extent *
185  u64 len);
187  struct btrfs_ordered_extent *ordered);
189 void btrfs_run_ordered_operations(struct btrfs_root *root, int wait);
191  struct btrfs_root *root,
192  struct inode *inode);
193 void btrfs_wait_ordered_extents(struct btrfs_root *root, int delay_iput);
194 int __init ordered_data_init(void);
195 void ordered_data_exit(void);
196 #endif