• Home
  • History
  • Annotate
  • Line#
  • Navigate
  • Raw
  • Download
  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6.36/fs/btrfs/
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
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 */
35struct btrfs_sector_sum {
36	/* bytenr on disk */
37	u64 bytenr;
38	u32 sum;
39};
40
41struct btrfs_ordered_sum {
42	/* bytenr is the start of this extent on disk */
43	u64 bytenr;
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 */
51	struct btrfs_sector_sum 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 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
77struct btrfs_ordered_extent {
78	/* logical offset in the file */
79	u64 file_offset;
80
81	/* disk byte number */
82	u64 start;
83
84	/* ram length of the extent in bytes */
85	u64 len;
86
87	/* extent length on disk */
88	u64 disk_len;
89
90	/* number of bytes that still need writing */
91	u64 bytes_left;
92
93	/* flags (described above) */
94	unsigned long flags;
95
96	/* reference count */
97	atomic_t refs;
98
99	/* the inode we belong to */
100	struct inode *inode;
101
102	/* list of checksums for insertion when the extent io is done */
103	struct list_head list;
104
105	/* used to wait for the BTRFS_ORDERED_COMPLETE bit */
106	wait_queue_head_t wait;
107
108	/* our friendly rbtree entry */
109	struct rb_node rb_node;
110
111	/* a per root list of all the pending ordered extents */
112	struct list_head root_extent_list;
113};
114
115
116/*
117 * calculates the total size you need to allocate for an ordered sum
118 * structure spanning 'bytes' in the file
119 */
120static inline int btrfs_ordered_sum_size(struct btrfs_root *root,
121					 unsigned long bytes)
122{
123	unsigned long num_sectors = (bytes + root->sectorsize - 1) /
124		root->sectorsize;
125	num_sectors++;
126	return sizeof(struct btrfs_ordered_sum) +
127		num_sectors * sizeof(struct btrfs_sector_sum);
128}
129
130static inline void
131btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
132{
133	spin_lock_init(&t->lock);
134	t->tree = RB_ROOT;
135	t->last = NULL;
136}
137
138int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
139int btrfs_remove_ordered_extent(struct inode *inode,
140				struct btrfs_ordered_extent *entry);
141int btrfs_dec_test_ordered_pending(struct inode *inode,
142				   struct btrfs_ordered_extent **cached,
143				   u64 file_offset, u64 io_size);
144int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
145			     u64 start, u64 len, u64 disk_len, int type);
146int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
147				 u64 start, u64 len, u64 disk_len, int type);
148int btrfs_add_ordered_sum(struct inode *inode,
149			  struct btrfs_ordered_extent *entry,
150			  struct btrfs_ordered_sum *sum);
151struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
152							 u64 file_offset);
153void btrfs_start_ordered_extent(struct inode *inode,
154				struct btrfs_ordered_extent *entry, int wait);
155int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
156struct btrfs_ordered_extent *
157btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
158struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
159							u64 file_offset,
160							u64 len);
161int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
162				struct btrfs_ordered_extent *ordered);
163int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, u32 *sum);
164int btrfs_run_ordered_operations(struct btrfs_root *root, int wait);
165int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
166				struct btrfs_root *root,
167				struct inode *inode);
168int btrfs_wait_ordered_extents(struct btrfs_root *root,
169			       int nocow_only, int delay_iput);
170#endif
171