xref: /openbmc/linux/fs/btrfs/free-space-cache.h (revision 54d687c1)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2009 Oracle.  All rights reserved.
4  */
5 
6 #ifndef BTRFS_FREE_SPACE_CACHE_H
7 #define BTRFS_FREE_SPACE_CACHE_H
8 
9 /*
10  * This is the trim state of an extent or bitmap.
11  *
12  * BTRFS_TRIM_STATE_TRIMMING is special and used to maintain the state of a
13  * bitmap as we may need several trims to fully trim a single bitmap entry.
14  * This is reset should any free space other than trimmed space be added to the
15  * bitmap.
16  */
17 enum btrfs_trim_state {
18 	BTRFS_TRIM_STATE_UNTRIMMED,
19 	BTRFS_TRIM_STATE_TRIMMED,
20 	BTRFS_TRIM_STATE_TRIMMING,
21 };
22 
23 struct btrfs_free_space {
24 	struct rb_node offset_index;
25 	struct rb_node bytes_index;
26 	u64 offset;
27 	u64 bytes;
28 	u64 max_extent_size;
29 	unsigned long *bitmap;
30 	struct list_head list;
31 	enum btrfs_trim_state trim_state;
32 	s32 bitmap_extents;
33 };
34 
btrfs_free_space_trimmed(struct btrfs_free_space * info)35 static inline bool btrfs_free_space_trimmed(struct btrfs_free_space *info)
36 {
37 	return (info->trim_state == BTRFS_TRIM_STATE_TRIMMED);
38 }
39 
btrfs_free_space_trimming_bitmap(struct btrfs_free_space * info)40 static inline bool btrfs_free_space_trimming_bitmap(
41 					    struct btrfs_free_space *info)
42 {
43 	return (info->trim_state == BTRFS_TRIM_STATE_TRIMMING);
44 }
45 
46 /*
47  * Deltas are an effective way to populate global statistics.  Give macro names
48  * to make it clear what we're doing.  An example is discard_extents in
49  * btrfs_free_space_ctl.
50  */
51 enum {
52 	BTRFS_STAT_CURR,
53 	BTRFS_STAT_PREV,
54 	BTRFS_STAT_NR_ENTRIES,
55 };
56 
57 struct btrfs_free_space_ctl {
58 	spinlock_t tree_lock;
59 	struct rb_root free_space_offset;
60 	struct rb_root_cached free_space_bytes;
61 	u64 free_space;
62 	int extents_thresh;
63 	int free_extents;
64 	int total_bitmaps;
65 	int unit;
66 	u64 start;
67 	s32 discardable_extents[BTRFS_STAT_NR_ENTRIES];
68 	s64 discardable_bytes[BTRFS_STAT_NR_ENTRIES];
69 	const struct btrfs_free_space_op *op;
70 	struct btrfs_block_group *block_group;
71 	struct mutex cache_writeout_mutex;
72 	struct list_head trimming_ranges;
73 };
74 
75 struct btrfs_free_space_op {
76 	bool (*use_bitmap)(struct btrfs_free_space_ctl *ctl,
77 			   struct btrfs_free_space *info);
78 };
79 
80 struct btrfs_io_ctl {
81 	void *cur, *orig;
82 	struct page *page;
83 	struct page **pages;
84 	struct btrfs_fs_info *fs_info;
85 	struct inode *inode;
86 	unsigned long size;
87 	int index;
88 	int num_pages;
89 	int entries;
90 	int bitmaps;
91 };
92 
93 int __init btrfs_free_space_init(void);
94 void __cold btrfs_free_space_exit(void);
95 struct inode *lookup_free_space_inode(struct btrfs_block_group *block_group,
96 		struct btrfs_path *path);
97 int create_free_space_inode(struct btrfs_trans_handle *trans,
98 			    struct btrfs_block_group *block_group,
99 			    struct btrfs_path *path);
100 int btrfs_remove_free_space_inode(struct btrfs_trans_handle *trans,
101 				  struct inode *inode,
102 				  struct btrfs_block_group *block_group);
103 
104 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
105 				    struct btrfs_block_group *block_group,
106 				    struct inode *inode);
107 int load_free_space_cache(struct btrfs_block_group *block_group);
108 int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
109 			struct btrfs_block_group *block_group,
110 			struct btrfs_path *path);
111 int btrfs_write_out_cache(struct btrfs_trans_handle *trans,
112 			  struct btrfs_block_group *block_group,
113 			  struct btrfs_path *path);
114 
115 void btrfs_init_free_space_ctl(struct btrfs_block_group *block_group,
116 			       struct btrfs_free_space_ctl *ctl);
117 int __btrfs_add_free_space(struct btrfs_block_group *block_group, u64 bytenr,
118 			   u64 size, enum btrfs_trim_state trim_state);
119 int btrfs_add_free_space(struct btrfs_block_group *block_group,
120 			 u64 bytenr, u64 size);
121 int btrfs_add_free_space_unused(struct btrfs_block_group *block_group,
122 				u64 bytenr, u64 size);
123 int btrfs_add_free_space_async_trimmed(struct btrfs_block_group *block_group,
124 				       u64 bytenr, u64 size);
125 int btrfs_remove_free_space(struct btrfs_block_group *block_group,
126 			    u64 bytenr, u64 size);
127 void btrfs_remove_free_space_cache(struct btrfs_block_group *block_group);
128 bool btrfs_is_free_space_trimmed(struct btrfs_block_group *block_group);
129 u64 btrfs_find_space_for_alloc(struct btrfs_block_group *block_group,
130 			       u64 offset, u64 bytes, u64 empty_size,
131 			       u64 *max_extent_size);
132 void btrfs_dump_free_space(struct btrfs_block_group *block_group,
133 			   u64 bytes);
134 int btrfs_find_space_cluster(struct btrfs_block_group *block_group,
135 			     struct btrfs_free_cluster *cluster,
136 			     u64 offset, u64 bytes, u64 empty_size);
137 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster);
138 u64 btrfs_alloc_from_cluster(struct btrfs_block_group *block_group,
139 			     struct btrfs_free_cluster *cluster, u64 bytes,
140 			     u64 min_start, u64 *max_extent_size);
141 void btrfs_return_cluster_to_free_space(
142 			       struct btrfs_block_group *block_group,
143 			       struct btrfs_free_cluster *cluster);
144 int btrfs_trim_block_group(struct btrfs_block_group *block_group,
145 			   u64 *trimmed, u64 start, u64 end, u64 minlen);
146 int btrfs_trim_block_group_extents(struct btrfs_block_group *block_group,
147 				   u64 *trimmed, u64 start, u64 end, u64 minlen,
148 				   bool async);
149 int btrfs_trim_block_group_bitmaps(struct btrfs_block_group *block_group,
150 				   u64 *trimmed, u64 start, u64 end, u64 minlen,
151 				   u64 maxlen, bool async);
152 
153 bool btrfs_free_space_cache_v1_active(struct btrfs_fs_info *fs_info);
154 int btrfs_set_free_space_cache_v1_active(struct btrfs_fs_info *fs_info, bool active);
155 /* Support functions for running our sanity tests */
156 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
157 int test_add_free_space_entry(struct btrfs_block_group *cache,
158 			      u64 offset, u64 bytes, bool bitmap);
159 int test_check_exists(struct btrfs_block_group *cache, u64 offset, u64 bytes);
160 #endif
161 
162 #endif
163