xref: /openbmc/linux/fs/btrfs/ordered-data.h (revision dc6a81c3)
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 	/*
56 	 * indicates whether this ordered extent has done its due diligence in
57 	 * updating the isize
58 	 */
59 	BTRFS_ORDERED_UPDATED_ISIZE,
60 	/* Set when we have to truncate an extent */
61 	BTRFS_ORDERED_TRUNCATED,
62 	/* Regular IO for COW */
63 	BTRFS_ORDERED_REGULAR,
64 };
65 
66 struct btrfs_ordered_extent {
67 	/* logical offset in the file */
68 	u64 file_offset;
69 
70 	/*
71 	 * These fields directly correspond to the same fields in
72 	 * btrfs_file_extent_item.
73 	 */
74 	u64 disk_bytenr;
75 	u64 num_bytes;
76 	u64 disk_num_bytes;
77 
78 	/* number of bytes that still need writing */
79 	u64 bytes_left;
80 
81 	/*
82 	 * the end of the ordered extent which is behind it but
83 	 * didn't update disk_i_size. Please see the comment of
84 	 * btrfs_ordered_update_i_size();
85 	 */
86 	u64 outstanding_isize;
87 
88 	/*
89 	 * If we get truncated we need to adjust the file extent we enter for
90 	 * this ordered extent so that we do not expose stale data.
91 	 */
92 	u64 truncated_len;
93 
94 	/* flags (described above) */
95 	unsigned long flags;
96 
97 	/* compression algorithm */
98 	int compress_type;
99 
100 	/* reference count */
101 	refcount_t refs;
102 
103 	/* the inode we belong to */
104 	struct inode *inode;
105 
106 	/* list of checksums for insertion when the extent io is done */
107 	struct list_head list;
108 
109 	/* If we need to wait on this to be done */
110 	struct list_head log_list;
111 
112 	/* If the transaction needs to wait on this ordered extent */
113 	struct list_head trans_list;
114 
115 	/* used to wait for the BTRFS_ORDERED_COMPLETE bit */
116 	wait_queue_head_t wait;
117 
118 	/* our friendly rbtree entry */
119 	struct rb_node rb_node;
120 
121 	/* a per root list of all the pending ordered extents */
122 	struct list_head root_extent_list;
123 
124 	struct btrfs_work work;
125 
126 	struct completion completion;
127 	struct btrfs_work flush_work;
128 	struct list_head work_list;
129 };
130 
131 /*
132  * calculates the total size you need to allocate for an ordered sum
133  * structure spanning 'bytes' in the file
134  */
135 static inline int btrfs_ordered_sum_size(struct btrfs_fs_info *fs_info,
136 					 unsigned long bytes)
137 {
138 	int num_sectors = (int)DIV_ROUND_UP(bytes, fs_info->sectorsize);
139 	int csum_size = btrfs_super_csum_size(fs_info->super_copy);
140 
141 	return sizeof(struct btrfs_ordered_sum) + num_sectors * csum_size;
142 }
143 
144 static inline void
145 btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
146 {
147 	spin_lock_init(&t->lock);
148 	t->tree = RB_ROOT;
149 	t->last = NULL;
150 }
151 
152 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
153 void btrfs_remove_ordered_extent(struct inode *inode,
154 				struct btrfs_ordered_extent *entry);
155 int btrfs_dec_test_ordered_pending(struct inode *inode,
156 				   struct btrfs_ordered_extent **cached,
157 				   u64 file_offset, u64 io_size, int uptodate);
158 int btrfs_dec_test_first_ordered_pending(struct inode *inode,
159 				   struct btrfs_ordered_extent **cached,
160 				   u64 *file_offset, u64 io_size,
161 				   int uptodate);
162 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
163 			     u64 disk_bytenr, u64 num_bytes, u64 disk_num_bytes,
164 			     int type);
165 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
166 				 u64 disk_bytenr, u64 num_bytes,
167 				 u64 disk_num_bytes, int type);
168 int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
169 				      u64 disk_bytenr, u64 num_bytes,
170 				      u64 disk_num_bytes, int type,
171 				      int compress_type);
172 void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
173 			   struct btrfs_ordered_sum *sum);
174 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
175 							 u64 file_offset);
176 void btrfs_start_ordered_extent(struct inode *inode,
177 				struct btrfs_ordered_extent *entry, int wait);
178 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
179 struct btrfs_ordered_extent *
180 btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
181 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
182 		struct btrfs_inode *inode,
183 		u64 file_offset,
184 		u64 len);
185 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
186 				struct btrfs_ordered_extent *ordered);
187 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
188 			   u8 *sum, int len);
189 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
190 			       const u64 range_start, const u64 range_len);
191 void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
192 			      const u64 range_start, const u64 range_len);
193 void btrfs_lock_and_flush_ordered_range(struct extent_io_tree *tree,
194 					struct btrfs_inode *inode, u64 start,
195 					u64 end,
196 					struct extent_state **cached_state);
197 int __init ordered_data_init(void);
198 void __cold ordered_data_exit(void);
199 
200 #endif
201