xref: /openbmc/linux/fs/btrfs/ordered-data.h (revision a09d2831)
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 */
23 struct btrfs_ordered_inode_tree {
24 	struct mutex mutex;
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  */
35 struct btrfs_sector_sum {
36 	/* bytenr on disk */
37 	u64 bytenr;
38 	u32 sum;
39 };
40 
41 struct 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 struct btrfs_ordered_extent {
76 	/* logical offset in the file */
77 	u64 file_offset;
78 
79 	/* disk byte number */
80 	u64 start;
81 
82 	/* ram length of the extent in bytes */
83 	u64 len;
84 
85 	/* extent length on disk */
86 	u64 disk_len;
87 
88 	/* number of bytes that still need writing */
89 	u64 bytes_left;
90 
91 	/* flags (described above) */
92 	unsigned long flags;
93 
94 	/* reference count */
95 	atomic_t refs;
96 
97 	/* the inode we belong to */
98 	struct inode *inode;
99 
100 	/* list of checksums for insertion when the extent io is done */
101 	struct list_head list;
102 
103 	/* used to wait for the BTRFS_ORDERED_COMPLETE bit */
104 	wait_queue_head_t wait;
105 
106 	/* our friendly rbtree entry */
107 	struct rb_node rb_node;
108 
109 	/* a per root list of all the pending ordered extents */
110 	struct list_head root_extent_list;
111 };
112 
113 
114 /*
115  * calculates the total size you need to allocate for an ordered sum
116  * structure spanning 'bytes' in the file
117  */
118 static inline int btrfs_ordered_sum_size(struct btrfs_root *root,
119 					 unsigned long bytes)
120 {
121 	unsigned long num_sectors = (bytes + root->sectorsize - 1) /
122 		root->sectorsize;
123 	num_sectors++;
124 	return sizeof(struct btrfs_ordered_sum) +
125 		num_sectors * sizeof(struct btrfs_sector_sum);
126 }
127 
128 static inline void
129 btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
130 {
131 	mutex_init(&t->mutex);
132 	t->tree.rb_node = NULL;
133 	t->last = NULL;
134 }
135 
136 int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
137 int btrfs_remove_ordered_extent(struct inode *inode,
138 				struct btrfs_ordered_extent *entry);
139 int btrfs_dec_test_ordered_pending(struct inode *inode,
140 				       u64 file_offset, u64 io_size);
141 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
142 			     u64 start, u64 len, u64 disk_len, int tyep);
143 int btrfs_add_ordered_sum(struct inode *inode,
144 			  struct btrfs_ordered_extent *entry,
145 			  struct btrfs_ordered_sum *sum);
146 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
147 							 u64 file_offset);
148 void btrfs_start_ordered_extent(struct inode *inode,
149 				struct btrfs_ordered_extent *entry, int wait);
150 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
151 struct btrfs_ordered_extent *
152 btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
153 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
154 				struct btrfs_ordered_extent *ordered);
155 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, u32 *sum);
156 int btrfs_run_ordered_operations(struct btrfs_root *root, int wait);
157 int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
158 				struct btrfs_root *root,
159 				struct inode *inode);
160 int btrfs_wait_ordered_extents(struct btrfs_root *root,
161 			       int nocow_only, int delay_iput);
162 #endif
163