xref: /linux/fs/btrfs/block-rsv.h (revision 6f7e6393d1ce636bb7ec77a7fe7b77458fddf701)
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_REMAP,
26 	BTRFS_BLOCK_RSV_DELOPS,
27 	BTRFS_BLOCK_RSV_DELREFS,
28 	BTRFS_BLOCK_RSV_TREELOG,
29 	BTRFS_BLOCK_RSV_EMPTY,
30 	BTRFS_BLOCK_RSV_TEMP,
31 };
32 
33 struct btrfs_block_rsv {
34 	u64 size;
35 	u64 reserved;
36 	struct btrfs_space_info *space_info;
37 	spinlock_t lock;
38 	bool full;
39 	bool failfast;
40 	/* Block reserve type, one of BTRFS_BLOCK_RSV_* */
41 	enum btrfs_rsv_type type:8;
42 
43 	/*
44 	 * Qgroup equivalent for @size @reserved
45 	 *
46 	 * Unlike normal @size/@reserved for inode rsv, qgroup doesn't care
47 	 * about things like csum size nor how many tree blocks it will need to
48 	 * reserve.
49 	 *
50 	 * Qgroup cares more about net change of the extent usage.
51 	 *
52 	 * So for one newly inserted file extent, in worst case it will cause
53 	 * leaf split and level increase, nodesize for each file extent is
54 	 * already too much.
55 	 *
56 	 * In short, qgroup_size/reserved is the upper limit of possible needed
57 	 * qgroup metadata reservation.
58 	 */
59 	u64 qgroup_rsv_size;
60 	u64 qgroup_rsv_reserved;
61 };
62 
63 void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, enum btrfs_rsv_type type);
64 void btrfs_init_root_block_rsv(struct btrfs_root *root);
65 struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_fs_info *fs_info,
66 					      enum btrfs_rsv_type type);
67 void btrfs_init_metadata_block_rsv(struct btrfs_fs_info *fs_info,
68 				   struct btrfs_block_rsv *rsv,
69 				   enum btrfs_rsv_type type);
70 void btrfs_free_block_rsv(struct btrfs_fs_info *fs_info,
71 			  struct btrfs_block_rsv *rsv);
72 int btrfs_block_rsv_add(struct btrfs_fs_info *fs_info,
73 			struct btrfs_block_rsv *block_rsv, u64 num_bytes,
74 			enum btrfs_reserve_flush_enum flush);
75 int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_percent);
76 int btrfs_block_rsv_refill(struct btrfs_fs_info *fs_info,
77 			   struct btrfs_block_rsv *block_rsv, u64 num_bytes,
78 			   enum btrfs_reserve_flush_enum flush);
79 int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
80 			    struct btrfs_block_rsv *dst_rsv, u64 num_bytes,
81 			    bool update_size);
82 int btrfs_block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv, u64 num_bytes);
83 void btrfs_block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
84 			       u64 num_bytes, bool update_size);
85 u64 btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
86 			      struct btrfs_block_rsv *block_rsv,
87 			      u64 num_bytes, u64 *qgroup_to_release);
88 void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info);
89 void btrfs_init_global_block_rsv(struct btrfs_fs_info *fs_info);
90 void btrfs_release_global_block_rsv(struct btrfs_fs_info *fs_info);
91 struct btrfs_block_rsv *btrfs_use_block_rsv(struct btrfs_trans_handle *trans,
92 					    struct btrfs_root *root,
93 					    u32 blocksize);
94 int btrfs_check_trunc_cache_free_space(const struct btrfs_fs_info *fs_info,
95 				       struct btrfs_block_rsv *rsv);
96 static inline void btrfs_unuse_block_rsv(struct btrfs_fs_info *fs_info,
97 					 struct btrfs_block_rsv *block_rsv,
98 					 u32 blocksize)
99 {
100 	btrfs_block_rsv_add_bytes(block_rsv, blocksize, false);
101 	btrfs_block_rsv_release(fs_info, block_rsv, 0, NULL);
102 }
103 
104 /*
105  * Fast path to check if the reserve is full, may be carefully used outside of
106  * locks.
107  */
108 static inline bool btrfs_block_rsv_full(const struct btrfs_block_rsv *rsv)
109 {
110 	return data_race(rsv->full);
111 }
112 
113 /*
114  * Get the reserved mount of a block reserve in a context where getting a stale
115  * value is acceptable, instead of accessing it directly and trigger data race
116  * warning from KCSAN.
117  */
118 static inline u64 btrfs_block_rsv_reserved(struct btrfs_block_rsv *rsv)
119 {
120 	u64 ret;
121 
122 	spin_lock(&rsv->lock);
123 	ret = rsv->reserved;
124 	spin_unlock(&rsv->lock);
125 
126 	return ret;
127 }
128 
129 /*
130  * Get the size of a block reserve in a context where getting a stale value is
131  * acceptable, instead of accessing it directly and trigger data race warning
132  * from KCSAN.
133  */
134 static inline u64 btrfs_block_rsv_size(struct btrfs_block_rsv *rsv)
135 {
136 	u64 ret;
137 
138 	spin_lock(&rsv->lock);
139 	ret = rsv->size;
140 	spin_unlock(&rsv->lock);
141 
142 	return ret;
143 }
144 
145 #endif /* BTRFS_BLOCK_RSV_H */
146