1 /* SPDX-License-Identifier: GPL-2.0 */
2
3 #ifndef BTRFS_BLOCK_RSV_H
4 #define BTRFS_BLOCK_RSV_H
5
6 #include <linux/types.h>
7 #include <linux/compiler.h>
8 #include <linux/spinlock.h>
9
10 struct btrfs_trans_handle;
11 struct btrfs_root;
12 struct btrfs_space_info;
13 struct btrfs_block_rsv;
14 struct btrfs_fs_info;
15 enum btrfs_reserve_flush_enum;
16
17 /*
18 * Types of block reserves
19 */
20 enum btrfs_rsv_type {
21 BTRFS_BLOCK_RSV_GLOBAL,
22 BTRFS_BLOCK_RSV_DELALLOC,
23 BTRFS_BLOCK_RSV_TRANS,
24 BTRFS_BLOCK_RSV_CHUNK,
25 BTRFS_BLOCK_RSV_DELOPS,
26 BTRFS_BLOCK_RSV_DELREFS,
27 BTRFS_BLOCK_RSV_EMPTY,
28 BTRFS_BLOCK_RSV_TEMP,
29 };
30
31 struct btrfs_block_rsv {
32 u64 size;
33 u64 reserved;
34 struct btrfs_space_info *space_info;
35 spinlock_t lock;
36 bool full;
37 bool failfast;
38 /* Block reserve type, one of BTRFS_BLOCK_RSV_* */
39 enum btrfs_rsv_type type:8;
40
41 /*
42 * Qgroup equivalent for @size @reserved
43 *
44 * Unlike normal @size/@reserved for inode rsv, qgroup doesn't care
45 * about things like csum size nor how many tree blocks it will need to
46 * reserve.
47 *
48 * Qgroup cares more about net change of the extent usage.
49 *
50 * So for one newly inserted file extent, in worst case it will cause
51 * leaf split and level increase, nodesize for each file extent is
52 * already too much.
53 *
54 * In short, qgroup_size/reserved is the upper limit of possible needed
55 * qgroup metadata reservation.
56 */
57 u64 qgroup_rsv_size;
58 u64 qgroup_rsv_reserved;
59 };
60
61 void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, enum btrfs_rsv_type type);
62 void btrfs_init_root_block_rsv(struct btrfs_root *root);
63 struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_fs_info *fs_info,
64 enum btrfs_rsv_type type);
65 void btrfs_init_metadata_block_rsv(struct btrfs_fs_info *fs_info,
66 struct btrfs_block_rsv *rsv,
67 enum btrfs_rsv_type type);
68 void btrfs_free_block_rsv(struct btrfs_fs_info *fs_info,
69 struct btrfs_block_rsv *rsv);
70 int btrfs_block_rsv_add(struct btrfs_fs_info *fs_info,
71 struct btrfs_block_rsv *block_rsv, u64 num_bytes,
72 enum btrfs_reserve_flush_enum flush);
73 int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_percent);
74 int btrfs_block_rsv_refill(struct btrfs_fs_info *fs_info,
75 struct btrfs_block_rsv *block_rsv, u64 num_bytes,
76 enum btrfs_reserve_flush_enum flush);
77 int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
78 struct btrfs_block_rsv *dst_rsv, u64 num_bytes,
79 bool update_size);
80 int btrfs_block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv, u64 num_bytes);
81 void btrfs_block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
82 u64 num_bytes, bool update_size);
83 u64 btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
84 struct btrfs_block_rsv *block_rsv,
85 u64 num_bytes, u64 *qgroup_to_release);
86 void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info);
87 void btrfs_init_global_block_rsv(struct btrfs_fs_info *fs_info);
88 void btrfs_release_global_block_rsv(struct btrfs_fs_info *fs_info);
89 struct btrfs_block_rsv *btrfs_use_block_rsv(struct btrfs_trans_handle *trans,
90 struct btrfs_root *root,
91 u32 blocksize);
92 int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
93 struct btrfs_block_rsv *rsv);
94 static inline void btrfs_unuse_block_rsv(struct btrfs_fs_info *fs_info,
95 struct btrfs_block_rsv *block_rsv,
96 u32 blocksize)
97 {
98 btrfs_block_rsv_add_bytes(block_rsv, blocksize, false);
99 btrfs_block_rsv_release(fs_info, block_rsv, 0, NULL);
100 }
101
102 /*
103 * Fast path to check if the reserve is full, may be carefully used outside of
104 * locks.
105 */
106 static inline bool btrfs_block_rsv_full(const struct btrfs_block_rsv *rsv)
107 {
108 return data_race(rsv->full);
109 }
110
111 /*
112 * Get the reserved mount of a block reserve in a context where getting a stale
113 * value is acceptable, instead of accessing it directly and trigger data race
114 * warning from KCSAN.
115 */
116 static inline u64 btrfs_block_rsv_reserved(struct btrfs_block_rsv *rsv)
117 {
118 u64 ret;
119
120 spin_lock(&rsv->lock);
121 ret = rsv->reserved;
122 spin_unlock(&rsv->lock);
123
124 return ret;
125 }
126
127 /*
128 * Get the size of a block reserve in a context where getting a stale value is
129 * acceptable, instead of accessing it directly and trigger data race warning
130 * from KCSAN.
131 */
132 static inline u64 btrfs_block_rsv_size(struct btrfs_block_rsv *rsv)
133 {
134 u64 ret;
135
136 spin_lock(&rsv->lock);
137 ret = rsv->size;
138 spin_unlock(&rsv->lock);
139
140 return ret;
141 }
142
143 #endif /* BTRFS_BLOCK_RSV_H */
144
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