xref: /linux/fs/btrfs/free-space-cache.h (revision 36f353a1ebf88280f58d1ebfe2731251d9159456)
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 #include <linux/rbtree.h>
10 #include <linux/list.h>
11 #include <linux/spinlock.h>
12 #include <linux/mutex.h>
13 #include "fs.h"
14 
15 struct inode;
16 struct page;
17 struct btrfs_fs_info;
18 struct btrfs_path;
19 struct btrfs_trans_handle;
20 struct btrfs_trim_block_group;
21 
22 /*
23  * This is the trim state of an extent or bitmap.
24  *
25  * BTRFS_TRIM_STATE_TRIMMING is special and used to maintain the state of a
26  * bitmap as we may need several trims to fully trim a single bitmap entry.
27  * This is reset should any free space other than trimmed space be added to the
28  * bitmap.
29  */
30 enum btrfs_trim_state {
31 	BTRFS_TRIM_STATE_UNTRIMMED,
32 	BTRFS_TRIM_STATE_TRIMMED,
33 	BTRFS_TRIM_STATE_TRIMMING,
34 };
35 
36 struct btrfs_free_space {
37 	struct rb_node offset_index;
38 	struct rb_node bytes_index;
39 	u64 offset;
40 	u64 bytes;
41 	u64 max_extent_size;
42 	unsigned long *bitmap;
43 	struct list_head list;
44 	enum btrfs_trim_state trim_state;
45 	s32 bitmap_extents;
46 };
47 
48 static inline bool btrfs_free_space_trimmed(struct btrfs_free_space *info)
49 {
50 	return (info->trim_state == BTRFS_TRIM_STATE_TRIMMED);
51 }
52 
53 static inline bool btrfs_free_space_trimming_bitmap(
54 					    struct btrfs_free_space *info)
55 {
56 	return (info->trim_state == BTRFS_TRIM_STATE_TRIMMING);
57 }
58 
59 /*
60  * Deltas are an effective way to populate global statistics.  Give macro names
61  * to make it clear what we're doing.  An example is discard_extents in
62  * btrfs_free_space_ctl.
63  */
64 enum {
65 	BTRFS_STAT_CURR,
66 	BTRFS_STAT_PREV,
67 	BTRFS_STAT_NR_ENTRIES,
68 };
69 
70 struct btrfs_free_space_ctl {
71 	spinlock_t tree_lock;
72 	struct rb_root free_space_offset;
73 	struct rb_root_cached free_space_bytes;
74 	u64 free_space;
75 	int extents_thresh;
76 	int free_extents;
77 	int total_bitmaps;
78 	int unit;
79 	u64 start;
80 	s32 discardable_extents[BTRFS_STAT_NR_ENTRIES];
81 	s64 discardable_bytes[BTRFS_STAT_NR_ENTRIES];
82 	const struct btrfs_free_space_op *op;
83 	struct btrfs_block_group *block_group;
84 	struct mutex cache_writeout_mutex;
85 	struct list_head trimming_ranges;
86 };
87 
88 struct btrfs_free_space_op {
89 	bool (*use_bitmap)(struct btrfs_free_space_ctl *ctl,
90 			   struct btrfs_free_space *info);
91 };
92 
93 struct btrfs_io_ctl {
94 	void *cur, *orig;
95 	struct page *page;
96 	struct page **pages;
97 	struct btrfs_fs_info *fs_info;
98 	struct inode *inode;
99 	unsigned long size;
100 	int index;
101 	int num_pages;
102 	int entries;
103 	int bitmaps;
104 };
105 
106 int __init btrfs_free_space_init(void);
107 void __cold btrfs_free_space_exit(void);
108 struct inode *lookup_free_space_inode(struct btrfs_block_group *block_group,
109 		struct btrfs_path *path);
110 int create_free_space_inode(struct btrfs_trans_handle *trans,
111 			    struct btrfs_block_group *block_group,
112 			    struct btrfs_path *path);
113 int btrfs_remove_free_space_inode(struct btrfs_trans_handle *trans,
114 				  struct inode *inode,
115 				  struct btrfs_block_group *block_group);
116 
117 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
118 				    struct btrfs_block_group *block_group,
119 				    struct inode *inode);
120 int load_free_space_cache(struct btrfs_block_group *block_group);
121 int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
122 			struct btrfs_block_group *block_group,
123 			struct btrfs_path *path);
124 int btrfs_write_out_cache(struct btrfs_trans_handle *trans,
125 			  struct btrfs_block_group *block_group,
126 			  struct btrfs_path *path);
127 
128 void btrfs_init_free_space_ctl(struct btrfs_block_group *block_group,
129 			       struct btrfs_free_space_ctl *ctl);
130 int btrfs_add_free_space(struct btrfs_block_group *block_group,
131 			 u64 bytenr, u64 size);
132 int btrfs_add_free_space_unused(struct btrfs_block_group *block_group,
133 				u64 bytenr, u64 size);
134 int btrfs_add_free_space_async_trimmed(struct btrfs_block_group *block_group,
135 				       u64 bytenr, u64 size);
136 int btrfs_remove_free_space(struct btrfs_block_group *block_group,
137 			    u64 bytenr, u64 size);
138 void btrfs_remove_free_space_cache(struct btrfs_block_group *block_group);
139 bool btrfs_is_free_space_trimmed(struct btrfs_block_group *block_group);
140 u64 btrfs_find_space_for_alloc(struct btrfs_block_group *block_group,
141 			       u64 offset, u64 bytes, u64 empty_size,
142 			       u64 *max_extent_size);
143 void btrfs_dump_free_space(struct btrfs_block_group *block_group,
144 			   u64 bytes);
145 int btrfs_find_space_cluster(struct btrfs_block_group *block_group,
146 			     struct btrfs_free_cluster *cluster,
147 			     u64 offset, u64 bytes, u64 empty_size);
148 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster);
149 u64 btrfs_alloc_from_cluster(struct btrfs_block_group *block_group,
150 			     struct btrfs_free_cluster *cluster, u64 bytes,
151 			     u64 min_start, u64 *max_extent_size);
152 void btrfs_return_cluster_to_free_space(
153 			       struct btrfs_block_group *block_group,
154 			       struct btrfs_free_cluster *cluster);
155 int btrfs_trim_block_group(struct btrfs_block_group *block_group,
156 			   u64 *trimmed, u64 start, u64 end, u64 minlen);
157 int btrfs_trim_block_group_extents(struct btrfs_block_group *block_group,
158 				   u64 *trimmed, u64 start, u64 end, u64 minlen,
159 				   bool async);
160 int btrfs_trim_block_group_bitmaps(struct btrfs_block_group *block_group,
161 				   u64 *trimmed, u64 start, u64 end, u64 minlen,
162 				   u64 maxlen, bool async);
163 
164 bool btrfs_free_space_cache_v1_active(struct btrfs_fs_info *fs_info);
165 int btrfs_set_free_space_cache_v1_active(struct btrfs_fs_info *fs_info, bool active);
166 /* Support functions for running our sanity tests */
167 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
168 int test_add_free_space_entry(struct btrfs_block_group *cache,
169 			      u64 offset, u64 bytes, bool bitmap);
170 int test_check_exists(struct btrfs_block_group *cache, u64 offset, u64 bytes);
171 #endif
172 
173 #endif
174