xref: /openbmc/linux/fs/btrfs/ordered-data.h (revision df687341)
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 	u32 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 	/* disk byte number */
71 	u64 start;
72 
73 	/* ram length of the extent in bytes */
74 	u64 len;
75 
76 	/* extent length on disk */
77 	u64 disk_len;
78 
79 	/* number of bytes that still need writing */
80 	u64 bytes_left;
81 
82 	/*
83 	 * the end of the ordered extent which is behind it but
84 	 * didn't update disk_i_size. Please see the comment of
85 	 * btrfs_ordered_update_i_size();
86 	 */
87 	u64 outstanding_isize;
88 
89 	/*
90 	 * If we get truncated we need to adjust the file extent we enter for
91 	 * this ordered extent so that we do not expose stale data.
92 	 */
93 	u64 truncated_len;
94 
95 	/* flags (described above) */
96 	unsigned long flags;
97 
98 	/* compression algorithm */
99 	int compress_type;
100 
101 	/* reference count */
102 	refcount_t refs;
103 
104 	/* the inode we belong to */
105 	struct inode *inode;
106 
107 	/* list of checksums for insertion when the extent io is done */
108 	struct list_head list;
109 
110 	/* If we need to wait on this to be done */
111 	struct list_head log_list;
112 
113 	/* If the transaction needs to wait on this ordered extent */
114 	struct list_head trans_list;
115 
116 	/* used to wait for the BTRFS_ORDERED_COMPLETE bit */
117 	wait_queue_head_t wait;
118 
119 	/* our friendly rbtree entry */
120 	struct rb_node rb_node;
121 
122 	/* a per root list of all the pending ordered extents */
123 	struct list_head root_extent_list;
124 
125 	struct btrfs_work work;
126 
127 	struct completion completion;
128 	struct btrfs_work flush_work;
129 	struct list_head work_list;
130 };
131 
132 /*
133  * calculates the total size you need to allocate for an ordered sum
134  * structure spanning 'bytes' in the file
135  */
136 static inline int btrfs_ordered_sum_size(struct btrfs_fs_info *fs_info,
137 					 unsigned long bytes)
138 {
139 	int num_sectors = (int)DIV_ROUND_UP(bytes, fs_info->sectorsize);
140 	int csum_size = btrfs_super_csum_size(fs_info->super_copy);
141 
142 	return sizeof(struct btrfs_ordered_sum) + num_sectors * csum_size;
143 }
144 
145 static inline void
146 btrfs_ordered_inode_tree_init(struct btrfs_ordered_inode_tree *t)
147 {
148 	spin_lock_init(&t->lock);
149 	t->tree = RB_ROOT;
150 	t->last = NULL;
151 }
152 
153 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry);
154 void btrfs_remove_ordered_extent(struct inode *inode,
155 				struct btrfs_ordered_extent *entry);
156 int btrfs_dec_test_ordered_pending(struct inode *inode,
157 				   struct btrfs_ordered_extent **cached,
158 				   u64 file_offset, u64 io_size, int uptodate);
159 int btrfs_dec_test_first_ordered_pending(struct inode *inode,
160 				   struct btrfs_ordered_extent **cached,
161 				   u64 *file_offset, u64 io_size,
162 				   int uptodate);
163 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
164 			     u64 start, u64 len, u64 disk_len, int type);
165 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
166 				 u64 start, u64 len, u64 disk_len, int type);
167 int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
168 				      u64 start, u64 len, u64 disk_len,
169 				      int type, int compress_type);
170 void btrfs_add_ordered_sum(struct inode *inode,
171 			   struct btrfs_ordered_extent *entry,
172 			   struct btrfs_ordered_sum *sum);
173 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
174 							 u64 file_offset);
175 void btrfs_start_ordered_extent(struct inode *inode,
176 				struct btrfs_ordered_extent *entry, int wait);
177 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len);
178 struct btrfs_ordered_extent *
179 btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset);
180 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
181 		struct btrfs_inode *inode,
182 		u64 file_offset,
183 		u64 len);
184 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
185 				struct btrfs_ordered_extent *ordered);
186 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
187 			   u32 *sum, int len);
188 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
189 			       const u64 range_start, const u64 range_len);
190 u64 btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
191 			      const u64 range_start, const u64 range_len);
192 int __init ordered_data_init(void);
193 void __cold ordered_data_exit(void);
194 
195 #endif
196