summaryrefslogtreecommitdiffstats
path: root/fs/btrfs/space-info.h
blob: 3e304300fc6248e3569e754071e268df7069e3e8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef BTRFS_SPACE_INFO_H
#define BTRFS_SPACE_INFO_H

#include <trace/events/btrfs.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/kobject.h>
#include <linux/lockdep.h>
#include <linux/wait.h>
#include <linux/rwsem.h>
#include "volumes.h"

struct btrfs_fs_info;
struct btrfs_block_group;

/*
 * Different levels for to flush space when doing space reservations.
 *
 * The higher the level, the more methods we try to reclaim space.
 */
enum btrfs_reserve_flush_enum {
	/* If we are in the transaction, we can't flush anything.*/
	BTRFS_RESERVE_NO_FLUSH,

	/*
	 * Flush space by:
	 * - Running delayed inode items
	 * - Allocating a new chunk
	 */
	BTRFS_RESERVE_FLUSH_LIMIT,

	/*
	 * Flush space by:
	 * - Running delayed inode items
	 * - Running delayed refs
	 * - Running delalloc and waiting for ordered extents
	 * - Allocating a new chunk
	 * - Committing transaction
	 */
	BTRFS_RESERVE_FLUSH_EVICT,

	/*
	 * Flush space by above mentioned methods and by:
	 * - Running delayed iputs
	 * - Committing transaction
	 *
	 * Can be interrupted by a fatal signal.
	 */
	BTRFS_RESERVE_FLUSH_DATA,
	BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE,
	BTRFS_RESERVE_FLUSH_ALL,

	/*
	 * Pretty much the same as FLUSH_ALL, but can also steal space from
	 * global rsv.
	 *
	 * Can be interrupted by a fatal signal.
	 */
	BTRFS_RESERVE_FLUSH_ALL_STEAL,

	/*
	 * This is for btrfs_use_block_rsv only.  We have exhausted our block
	 * rsv and our global block rsv.  This can happen for things like
	 * delalloc where we are overwriting a lot of extents with a single
	 * extent and didn't reserve enough space.  Alternatively it can happen
	 * with delalloc where we reserve 1 extents worth for a large extent but
	 * fragmentation leads to multiple extents being created.  This will
	 * give us the reservation in the case of
	 *
	 * if (num_bytes < (space_info->total_bytes -
	 *		    btrfs_space_info_used(space_info, false))
	 *
	 * Which ignores bytes_may_use.  This is potentially dangerous, but our
	 * reservation system is generally pessimistic so is able to absorb this
	 * style of mistake.
	 */
	BTRFS_RESERVE_FLUSH_EMERGENCY,
};

enum btrfs_flush_state {
	FLUSH_DELAYED_ITEMS_NR	= 1,
	FLUSH_DELAYED_ITEMS	= 2,
	FLUSH_DELAYED_REFS_NR	= 3,
	FLUSH_DELAYED_REFS	= 4,
	FLUSH_DELALLOC		= 5,
	FLUSH_DELALLOC_WAIT	= 6,
	FLUSH_DELALLOC_FULL	= 7,
	ALLOC_CHUNK		= 8,
	ALLOC_CHUNK_FORCE	= 9,
	RUN_DELAYED_IPUTS	= 10,
	COMMIT_TRANS		= 11,
};

struct btrfs_space_info {
	spinlock_t lock;

	u64 total_bytes;	/* total bytes in the space,
				   this doesn't take mirrors into account */
	u64 bytes_used;		/* total bytes used,
				   this doesn't take mirrors into account */
	u64 bytes_pinned;	/* total bytes pinned, will be freed when the
				   transaction finishes */
	u64 bytes_reserved;	/* total bytes the allocator has reserved for
				   current allocations */
	u64 bytes_may_use;	/* number of bytes that may be used for
				   delalloc/allocations */
	u64 bytes_readonly;	/* total bytes that are read only */
	u64 bytes_zone_unusable;	/* total bytes that are unusable until
					   resetting the device zone */

	u64 max_extent_size;	/* This will hold the maximum extent size of
				   the space info if we had an ENOSPC in the
				   allocator. */
	/* Chunk size in bytes */
	u64 chunk_size;

	/*
	 * Once a block group drops below this threshold (percents) we'll
	 * schedule it for reclaim.
	 */
	int bg_reclaim_threshold;

	int clamp;		/* Used to scale our threshold for preemptive
				   flushing. The value is >> clamp, so turns
				   out to be a 2^clamp divisor. */

	unsigned int full:1;	/* indicates that we cannot allocate any more
				   chunks for this space */
	unsigned int chunk_alloc:1;	/* set if we are allocating a chunk */

	unsigned int flush:1;		/* set if we are trying to make space */

	unsigned int force_alloc;	/* set if we need to force a chunk
					   alloc for this space */

	u64 disk_used;		/* total bytes used on disk */
	u64 disk_total;		/* total bytes on disk, takes mirrors into
				   account */

	u64 flags;

	struct list_head list;
	/* Protected by the spinlock 'lock'. */
	struct list_head ro_bgs;
	struct list_head priority_tickets;
	struct list_head tickets;

	/*
	 * Size of space that needs to be reclaimed in order to satisfy pending
	 * tickets
	 */
	u64 reclaim_size;

	/*
	 * tickets_id just indicates the next ticket will be handled, so note
	 * it's not stored per ticket.
	 */
	u64 tickets_id;

	struct rw_semaphore groups_sem;
	/* for block groups in our same type */
	struct list_head block_groups[BTRFS_NR_RAID_TYPES];

	struct kobject kobj;
	struct kobject *block_group_kobjs[BTRFS_NR_RAID_TYPES];
};

struct reserve_ticket {
	u64 bytes;
	int error;
	bool steal;
	struct list_head list;
	wait_queue_head_t wait;
};

static inline bool btrfs_mixed_space_info(struct btrfs_space_info *space_info)
{
	return ((space_info->flags & BTRFS_BLOCK_GROUP_METADATA) &&
		(space_info->flags & BTRFS_BLOCK_GROUP_DATA));
}

/*
 *
 * Declare a helper function to detect underflow of various space info members
 */
#define DECLARE_SPACE_INFO_UPDATE(name, trace_name)			\
static inline void							\
btrfs_space_info_update_##name(struct btrfs_fs_info *fs_info,		\
			       struct btrfs_space_info *sinfo,		\
			       s64 bytes)				\
{									\
	const u64 abs_bytes = (bytes < 0) ? -bytes : bytes;		\
	lockdep_assert_held(&sinfo->lock);				\
	trace_update_##name(fs_info, sinfo, sinfo->name, bytes);	\
	trace_btrfs_space_reservation(fs_info, trace_name,		\
				      sinfo->flags, abs_bytes,		\
				      bytes > 0);			\
	if (bytes < 0 && sinfo->name < -bytes) {			\
		WARN_ON(1);						\
		sinfo->name = 0;					\
		return;							\
	}								\
	sinfo->name += bytes;						\
}

DECLARE_SPACE_INFO_UPDATE(bytes_may_use, "space_info");
DECLARE_SPACE_INFO_UPDATE(bytes_pinned, "pinned");
DECLARE_SPACE_INFO_UPDATE(bytes_zone_unusable, "zone_unusable");

int btrfs_init_space_info(struct btrfs_fs_info *fs_info);
void btrfs_add_bg_to_space_info(struct btrfs_fs_info *info,
				struct btrfs_block_group *block_group);
void btrfs_update_space_info_chunk_size(struct btrfs_space_info *space_info,
					u64 chunk_size);
struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info,
					       u64 flags);
u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info,
			  bool may_use_included);
void btrfs_clear_space_info_full(struct btrfs_fs_info *info);
void btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
			   struct btrfs_space_info *info, u64 bytes,
			   int dump_block_groups);
int btrfs_reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
				 struct btrfs_space_info *space_info,
				 u64 orig_bytes,
				 enum btrfs_reserve_flush_enum flush);
void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info,
				struct btrfs_space_info *space_info);
int btrfs_can_overcommit(struct btrfs_fs_info *fs_info,
			 struct btrfs_space_info *space_info, u64 bytes,
			 enum btrfs_reserve_flush_enum flush);

static inline void btrfs_space_info_free_bytes_may_use(
				struct btrfs_fs_info *fs_info,
				struct btrfs_space_info *space_info,
				u64 num_bytes)
{
	spin_lock(&space_info->lock);
	btrfs_space_info_update_bytes_may_use(fs_info, space_info, -num_bytes);
	btrfs_try_granting_tickets(fs_info, space_info);
	spin_unlock(&space_info->lock);
}
int btrfs_reserve_data_bytes(struct btrfs_fs_info *fs_info, u64 bytes,
			     enum btrfs_reserve_flush_enum flush);
void btrfs_dump_space_info_for_trans_abort(struct btrfs_fs_info *fs_info);
void btrfs_init_async_reclaim_work(struct btrfs_fs_info *fs_info);
u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo);

#endif /* BTRFS_SPACE_INFO_H */