xref: /openbmc/linux/fs/btrfs/ordered-data.h (revision 37744fee)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2007 Oracle.  All rights reserved.
4  */
5 
6 #ifndef BTRFS_ORDERED_DATA_H
7 #define BTRFS_ORDERED_DATA_H
8 
9 /* one of these per inode */
10 struct btrfs_ordered_inode_tree {
11 	spinlock_t lock;
12 	struct rb_root tree;
13 	struct rb_node *last;
14 };
15 
16 struct btrfs_ordered_sum {
17 	/* bytenr is the start of this extent on disk */
18 	u64 bytenr;
19 
20 	/*
21 	 * this is the length in bytes covered by the sums array below.
22 	 */
23 	int len;
24 	struct list_head list;
25 	/* last field is a variable length array of csums */
26 	u8 sums[];
27 };
28 
29 /*
30  * bits for the flags field:
31  *
32  * BTRFS_ORDERED_IO_DONE is set when all of the blocks are written.
33  * It is used to make sure metadata is inserted into the tree only once
34  * per extent.
35  *
36  * BTRFS_ORDERED_COMPLETE is set when the extent is removed from the
37  * rbtree, just before waking any waiters.  It is used to indicate the
38  * IO is done and any metadata is inserted into the tree.
39  */
40 enum {
41 	/* set when all the pages are written */
42 	BTRFS_ORDERED_IO_DONE,
43 	/* set when removed from the tree */
44 	BTRFS_ORDERED_COMPLETE,
45 	/* set when we want to write in place */
46 	BTRFS_ORDERED_NOCOW,
47 	/* writing a zlib compressed extent */
48 	BTRFS_ORDERED_COMPRESSED,
49 	/* set when writing to preallocated extent */
50 	BTRFS_ORDERED_PREALLOC,
51 	/* set when we're doing DIO with this extent */
52 	BTRFS_ORDERED_DIRECT,
53 	/* We had an io error when writing this out */
54 	BTRFS_ORDERED_IOERR,
55 	/* Set when we have to truncate an extent */
56 	BTRFS_ORDERED_TRUNCATED,
57 	/* Regular IO for COW */
58 	BTRFS_ORDERED_REGULAR,
59 };
60 
61 struct btrfs_ordered_extent {
62 	/* logical offset in the file */
63 	u64 file_offset;
64 
65 	/*
66 	 * These fields directly correspond to the same fields in
67 	 * btrfs_file_extent_item.
68 	 */
69 	u64 disk_bytenr;
70 	u64 num_bytes;
71 	u64 disk_num_bytes;
72 
73 	/* number of bytes that still need writing */
74 	u64 bytes_left;
75 
76 	/*
77 	 * the end of the ordered extent which is behind it but
78 	 * didn't update disk_i_size. Please see the comment of
79 	 * btrfs_ordered_update_i_size();
80 	 */
81 	u64 outstanding_isize;
82 
83 	/*
84 	 * If we get truncated we need to adjust the file extent we enter for
85 	 * this ordered extent so that we do not expose stale data.
86 	 */
87 	u64 truncated_len;
88 
89 	/* flags (described above) */
90 	unsigned long flags;
91 
92 	/* compression algorithm */
93 	int compress_type;
94 
95 	/* reference count */
96 	refcount_t refs;
97 
98 	/* the inode we belong to */
99 	struct inode *inode;
100 
101 	/* list of checksums for insertion when the extent io is done */
102 	struct list_head list;
103 
104 	/* If we need to wait on this to be done */
105 	struct list_head log_list;
106 
107 	/* If the transaction needs to wait on this ordered extent */
108 	struct list_head trans_list;
109 
110 	/* used to wait for the BTRFS_ORDERED_COMPLETE bit */
111 	wait_queue_head_t wait;
112 
113 	/* our friendly rbtree entry */
114 	struct rb_node rb_node;
115 
116 	/* a per root list of all the pending ordered extents */
117 	struct list_head root_extent_list;
118 
119 	struct btrfs_work work;
120 
121 	struct completion completion;
122 	struct btrfs_work flush_work;
123 	struct list_head work_list;
124 };
125 
126 /*
127  * calculates the total size you need to allocate for an ordered sum
128  * structure spanning 'bytes' in the file
129  */
130 static inline int btrfs_ordered_sum_size(struct btrfs_fs_info *fs_info,
131 					 unsigned long bytes)
132 {
133 	int num_sectors = (int)DIV_ROUND_UP(bytes, fs_info->sectorsize);
134 	int csum_size = btrfs_super_csum_size(fs_info->super_copy);
135 
136 	return sizeof(struct btrfs_ordered_sum) + num_sectors * csum_size;
137 }
138 
139 static inline void
140 btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
141 {
142 	spin_lock_init(&t->lock);
143 	t->tree = RB_ROOT;
144 	t->last = NULL;
145 }
146 
147 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
148 void btrfs_remove_ordered_extent(struct inode *inode,
149 				struct btrfs_ordered_extent *entry);
150 int btrfs_dec_test_ordered_pending(struct inode *inode,
151 				   struct btrfs_ordered_extent **cached,
152 				   u64 file_offset, u64 io_size, int uptodate);
153 int btrfs_dec_test_first_ordered_pending(struct inode *inode,
154 				   struct btrfs_ordered_extent **cached,
155 				   u64 *file_offset, u64 io_size,
156 				   int uptodate);
157 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
158 			     u64 disk_bytenr, u64 num_bytes, u64 disk_num_bytes,
159 			     int type);
160 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
161 				 u64 disk_bytenr, u64 num_bytes,
162 				 u64 disk_num_bytes, int type);
163 int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
164 				      u64 disk_bytenr, u64 num_bytes,
165 				      u64 disk_num_bytes, int type,
166 				      int compress_type);
167 void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
168 			   struct btrfs_ordered_sum *sum);
169 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
170 							 u64 file_offset);
171 void btrfs_start_ordered_extent(struct inode *inode,
172 				struct btrfs_ordered_extent *entry, int wait);
173 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
174 struct btrfs_ordered_extent *
175 btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
176 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
177 		struct btrfs_inode *inode,
178 		u64 file_offset,
179 		u64 len);
180 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
181 			   u8 *sum, int len);
182 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
183 			       const u64 range_start, const u64 range_len);
184 void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
185 			      const u64 range_start, const u64 range_len);
186 void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
187 					u64 end,
188 					struct extent_state **cached_state);
189 int __init ordered_data_init(void);
190 void __cold ordered_data_exit(void);
191 
192 #endif
193