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
10struct btrfs_trans_handle;
11struct btrfs_root;
12struct btrfs_space_info;
13struct btrfs_block_rsv;
14struct btrfs_fs_info;
15enum btrfs_reserve_flush_enum;
16
17/*
18 * Types of block reserves
19 */
20enum 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
31struct 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
61void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, enum btrfs_rsv_type type);
62void btrfs_init_root_block_rsv(struct btrfs_root *root);
63struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_fs_info *fs_info,
64					      enum btrfs_rsv_type type);
65void btrfs_init_metadata_block_rsv(struct btrfs_fs_info *fs_info,
66				   struct btrfs_block_rsv *rsv,
67				   enum btrfs_rsv_type type);
68void btrfs_free_block_rsv(struct btrfs_fs_info *fs_info,
69			  struct btrfs_block_rsv *rsv);
70int 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);
73int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_percent);
74int 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);
77int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
78			    struct btrfs_block_rsv *dst_rsv, u64 num_bytes,
79			    bool update_size);
80int btrfs_block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv, u64 num_bytes);
81void btrfs_block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
82			       u64 num_bytes, bool update_size);
83u64 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);
86void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info);
87void btrfs_init_global_block_rsv(struct btrfs_fs_info *fs_info);
88void btrfs_release_global_block_rsv(struct btrfs_fs_info *fs_info);
89struct btrfs_block_rsv *btrfs_use_block_rsv(struct btrfs_trans_handle *trans,
90					    struct btrfs_root *root,
91					    u32 blocksize);
92int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
93				       struct btrfs_block_rsv *rsv);
94static 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 */
106static 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 */
116static 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 */
132static 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