xref: /linux/fs/btrfs/ordered-data.h (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 	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  */
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 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 whether this ordered extent
80 				       * has done its due diligence in updating
81 				       * the isize. */
82 
83 struct btrfs_ordered_extent {
84 	/* logical offset in the file */
85 	u64 file_offset;
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 */
97 	u64 bytes_left;
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 	 */
104 	u64 outstanding_isize;
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 	/* used to wait for the BTRFS_ORDERED_COMPLETE bit */
122 	wait_queue_head_t wait;
123 
124 	/* our friendly rbtree entry */
125 	struct rb_node rb_node;
126 
127 	/* a per root list of all the pending ordered extents */
128 	struct list_head root_extent_list;
129 
130 	struct btrfs_work work;
131 
132 	struct completion completion;
133 	struct btrfs_work flush_work;
134 	struct list_head work_list;
135 };
136 
137 /*
138  * calculates the total size you need to allocate for an ordered sum
139  * structure spanning 'bytes' in the file
140  */
141 static inline int btrfs_ordered_sum_size(struct btrfs_root *root,
142 					 unsigned long bytes)
143 {
144 	unsigned long num_sectors = (bytes + root->sectorsize - 1) /
145 		root->sectorsize;
146 	num_sectors++;
147 	return sizeof(struct btrfs_ordered_sum) +
148 		num_sectors * sizeof(struct btrfs_sector_sum);
149 }
150 
151 static inline void
152 btrfs_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 
159 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
160 void btrfs_remove_ordered_extent(struct inode *inode,
161 				struct btrfs_ordered_extent *entry);
162 int btrfs_dec_test_ordered_pending(struct inode *inode,
163 				   struct btrfs_ordered_extent **cached,
164 				   u64 file_offset, u64 io_size, int uptodate);
165 int 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);
169 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
170 			     u64 start, u64 len, u64 disk_len, int type);
171 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
172 				 u64 start, u64 len, u64 disk_len, int type);
173 int 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);
176 void btrfs_add_ordered_sum(struct inode *inode,
177 			   struct btrfs_ordered_extent *entry,
178 			   struct btrfs_ordered_sum *sum);
179 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
180 							 u64 file_offset);
181 void btrfs_start_ordered_extent(struct inode *inode,
182 				struct btrfs_ordered_extent *entry, int wait);
183 void btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
184 struct btrfs_ordered_extent *
185 btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
186 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
187 							u64 file_offset,
188 							u64 len);
189 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
190 				struct btrfs_ordered_extent *ordered);
191 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr, u32 *sum);
192 int btrfs_run_ordered_operations(struct btrfs_root *root, int wait);
193 void btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
194 				 struct btrfs_root *root,
195 				 struct inode *inode);
196 void btrfs_wait_ordered_extents(struct btrfs_root *root, int delay_iput);
197 int __init ordered_data_init(void);
198 void ordered_data_exit(void);
199 #endif
200