xref: /linux/fs/btrfs/free-space-cache.h (revision eb952c47d154ba2aac794b99c66c3c45eb4cc4ec)
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 <linux/freezer.h>
14 #include "fs.h"
15 
16 struct inode;
17 struct page;
18 struct btrfs_fs_info;
19 struct btrfs_path;
20 struct btrfs_trans_handle;
21 struct btrfs_trim_block_group;
22 
23 /*
24  * This is the trim state of an extent or bitmap.
25  *
26  * BTRFS_TRIM_STATE_TRIMMING is special and used to maintain the state of a
27  * bitmap as we may need several trims to fully trim a single bitmap entry.
28  * This is reset should any free space other than trimmed space be added to the
29  * bitmap.
30  */
31 enum btrfs_trim_state {
32 	BTRFS_TRIM_STATE_UNTRIMMED,
33 	BTRFS_TRIM_STATE_TRIMMED,
34 	BTRFS_TRIM_STATE_TRIMMING,
35 };
36 
37 struct btrfs_free_space {
38 	struct rb_node offset_index;
39 	struct rb_node bytes_index;
40 	u64 offset;
41 	u64 bytes;
42 	u64 max_extent_size;
43 	unsigned long *bitmap;
44 	struct list_head list;
45 	enum btrfs_trim_state trim_state;
46 	s32 bitmap_extents;
47 };
48 
btrfs_free_space_trimmed(struct btrfs_free_space * info)49 static inline bool btrfs_free_space_trimmed(struct btrfs_free_space *info)
50 {
51 	return (info->trim_state == BTRFS_TRIM_STATE_TRIMMED);
52 }
53 
btrfs_free_space_trimming_bitmap(struct btrfs_free_space * info)54 static inline bool btrfs_free_space_trimming_bitmap(
55 					    struct btrfs_free_space *info)
56 {
57 	return (info->trim_state == BTRFS_TRIM_STATE_TRIMMING);
58 }
59 
btrfs_trim_interrupted(void)60 static inline bool btrfs_trim_interrupted(void)
61 {
62 	return fatal_signal_pending(current) || freezing(current);
63 }
64 
65 /*
66  * Deltas are an effective way to populate global statistics.  Give macro names
67  * to make it clear what we're doing.  An example is discard_extents in
68  * btrfs_free_space_ctl.
69  */
70 enum {
71 	BTRFS_STAT_CURR,
72 	BTRFS_STAT_PREV,
73 	BTRFS_STAT_NR_ENTRIES,
74 };
75 
76 struct btrfs_free_space_ctl {
77 	spinlock_t tree_lock;
78 	struct rb_root free_space_offset;
79 	struct rb_root_cached free_space_bytes;
80 	u64 free_space;
81 	int extents_thresh;
82 	int free_extents;
83 	int total_bitmaps;
84 	int unit;
85 	u64 start;
86 	s32 discardable_extents[BTRFS_STAT_NR_ENTRIES];
87 	s64 discardable_bytes[BTRFS_STAT_NR_ENTRIES];
88 	const struct btrfs_free_space_op *op;
89 	struct btrfs_block_group *block_group;
90 	struct mutex cache_writeout_mutex;
91 	struct list_head trimming_ranges;
92 };
93 
94 struct btrfs_free_space_op {
95 	bool (*use_bitmap)(struct btrfs_free_space_ctl *ctl,
96 			   struct btrfs_free_space *info);
97 };
98 
99 struct btrfs_io_ctl {
100 	void *cur, *orig;
101 	struct page *page;
102 	struct page **pages;
103 	struct btrfs_fs_info *fs_info;
104 	struct inode *inode;
105 	unsigned long size;
106 	int index;
107 	int num_pages;
108 	int entries;
109 	int bitmaps;
110 };
111 
112 int __init btrfs_free_space_init(void);
113 void __cold btrfs_free_space_exit(void);
114 struct inode *lookup_free_space_inode(struct btrfs_block_group *block_group,
115 		struct btrfs_path *path);
116 int create_free_space_inode(struct btrfs_trans_handle *trans,
117 			    struct btrfs_block_group *block_group,
118 			    struct btrfs_path *path);
119 int btrfs_remove_free_space_inode(struct btrfs_trans_handle *trans,
120 				  struct inode *inode,
121 				  struct btrfs_block_group *block_group);
122 
123 int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
124 				    struct btrfs_block_group *block_group,
125 				    struct inode *inode);
126 int load_free_space_cache(struct btrfs_block_group *block_group);
127 int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
128 			struct btrfs_block_group *block_group,
129 			struct btrfs_path *path);
130 int btrfs_write_out_cache(struct btrfs_trans_handle *trans,
131 			  struct btrfs_block_group *block_group,
132 			  struct btrfs_path *path);
133 
134 void btrfs_init_free_space_ctl(struct btrfs_block_group *block_group,
135 			       struct btrfs_free_space_ctl *ctl);
136 int btrfs_add_free_space(struct btrfs_block_group *block_group,
137 			 u64 bytenr, u64 size);
138 int btrfs_add_free_space_unused(struct btrfs_block_group *block_group,
139 				u64 bytenr, u64 size);
140 int btrfs_add_free_space_async_trimmed(struct btrfs_block_group *block_group,
141 				       u64 bytenr, u64 size);
142 int btrfs_remove_free_space(struct btrfs_block_group *block_group,
143 			    u64 bytenr, u64 size);
144 void btrfs_remove_free_space_cache(struct btrfs_block_group *block_group);
145 bool btrfs_is_free_space_trimmed(struct btrfs_block_group *block_group);
146 u64 btrfs_find_space_for_alloc(struct btrfs_block_group *block_group,
147 			       u64 offset, u64 bytes, u64 empty_size,
148 			       u64 *max_extent_size);
149 void btrfs_dump_free_space(struct btrfs_block_group *block_group,
150 			   u64 bytes);
151 int btrfs_find_space_cluster(struct btrfs_block_group *block_group,
152 			     struct btrfs_free_cluster *cluster,
153 			     u64 offset, u64 bytes, u64 empty_size);
154 void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster);
155 u64 btrfs_alloc_from_cluster(struct btrfs_block_group *block_group,
156 			     struct btrfs_free_cluster *cluster, u64 bytes,
157 			     u64 min_start, u64 *max_extent_size);
158 void btrfs_return_cluster_to_free_space(
159 			       struct btrfs_block_group *block_group,
160 			       struct btrfs_free_cluster *cluster);
161 int btrfs_trim_block_group(struct btrfs_block_group *block_group,
162 			   u64 *trimmed, u64 start, u64 end, u64 minlen);
163 int btrfs_trim_block_group_extents(struct btrfs_block_group *block_group,
164 				   u64 *trimmed, u64 start, u64 end, u64 minlen,
165 				   bool async);
166 int btrfs_trim_block_group_bitmaps(struct btrfs_block_group *block_group,
167 				   u64 *trimmed, u64 start, u64 end, u64 minlen,
168 				   u64 maxlen, bool async);
169 
170 bool btrfs_free_space_cache_v1_active(struct btrfs_fs_info *fs_info);
171 int btrfs_set_free_space_cache_v1_active(struct btrfs_fs_info *fs_info, bool active);
172 /* Support functions for running our sanity tests */
173 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
174 int test_add_free_space_entry(struct btrfs_block_group *cache,
175 			      u64 offset, u64 bytes, bool bitmap);
176 int test_check_exists(struct btrfs_block_group *cache, u64 offset, u64 bytes);
177 #endif
178 
179 #endif
180