xref: /linux/fs/btrfs/space-info.h (revision 2697b79a469b68e3ad3640f55284359c1396278d)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 #ifndef BTRFS_SPACE_INFO_H
4 #define BTRFS_SPACE_INFO_H
5 
6 #include <trace/events/btrfs.h>
7 #include <linux/spinlock.h>
8 #include <linux/list.h>
9 #include <linux/kobject.h>
10 #include <linux/lockdep.h>
11 #include <linux/wait.h>
12 #include <linux/rwsem.h>
13 #include "volumes.h"
14 
15 struct btrfs_fs_info;
16 struct btrfs_block_group;
17 
18 /*
19  * Different levels for to flush space when doing space reservations.
20  *
21  * The higher the level, the more methods we try to reclaim space.
22  */
23 enum btrfs_reserve_flush_enum {
24 	/* If we are in the transaction, we can't flush anything.*/
25 	BTRFS_RESERVE_NO_FLUSH,
26 
27 	/*
28 	 * Flush space by:
29 	 * - Running delayed inode items
30 	 * - Allocating a new chunk
31 	 */
32 	BTRFS_RESERVE_FLUSH_LIMIT,
33 
34 	/*
35 	 * Flush space by:
36 	 * - Running delayed inode items
37 	 * - Running delayed refs
38 	 * - Running delalloc and waiting for ordered extents
39 	 * - Allocating a new chunk
40 	 * - Committing transaction
41 	 */
42 	BTRFS_RESERVE_FLUSH_EVICT,
43 
44 	/*
45 	 * Flush space by above mentioned methods and by:
46 	 * - Running delayed iputs
47 	 * - Committing transaction
48 	 *
49 	 * Can be interrupted by a fatal signal.
50 	 */
51 	BTRFS_RESERVE_FLUSH_DATA,
52 	BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE,
53 	BTRFS_RESERVE_FLUSH_ALL,
54 
55 	/*
56 	 * Pretty much the same as FLUSH_ALL, but can also steal space from
57 	 * global rsv.
58 	 *
59 	 * Can be interrupted by a fatal signal.
60 	 */
61 	BTRFS_RESERVE_FLUSH_ALL_STEAL,
62 
63 	/*
64 	 * This is for btrfs_use_block_rsv only.  We have exhausted our block
65 	 * rsv and our global block rsv.  This can happen for things like
66 	 * delalloc where we are overwriting a lot of extents with a single
67 	 * extent and didn't reserve enough space.  Alternatively it can happen
68 	 * with delalloc where we reserve 1 extents worth for a large extent but
69 	 * fragmentation leads to multiple extents being created.  This will
70 	 * give us the reservation in the case of
71 	 *
72 	 * if (num_bytes < (space_info->total_bytes -
73 	 *		    btrfs_space_info_used(space_info, false))
74 	 *
75 	 * Which ignores bytes_may_use.  This is potentially dangerous, but our
76 	 * reservation system is generally pessimistic so is able to absorb this
77 	 * style of mistake.
78 	 */
79 	BTRFS_RESERVE_FLUSH_EMERGENCY,
80 };
81 
82 enum btrfs_flush_state {
83 	FLUSH_DELAYED_ITEMS_NR	= 1,
84 	FLUSH_DELAYED_ITEMS	= 2,
85 	FLUSH_DELAYED_REFS_NR	= 3,
86 	FLUSH_DELAYED_REFS	= 4,
87 	FLUSH_DELALLOC		= 5,
88 	FLUSH_DELALLOC_WAIT	= 6,
89 	FLUSH_DELALLOC_FULL	= 7,
90 	ALLOC_CHUNK		= 8,
91 	ALLOC_CHUNK_FORCE	= 9,
92 	RUN_DELAYED_IPUTS	= 10,
93 	COMMIT_TRANS		= 11,
94 };
95 
96 struct btrfs_space_info {
97 	spinlock_t lock;
98 
99 	u64 total_bytes;	/* total bytes in the space,
100 				   this doesn't take mirrors into account */
101 	u64 bytes_used;		/* total bytes used,
102 				   this doesn't take mirrors into account */
103 	u64 bytes_pinned;	/* total bytes pinned, will be freed when the
104 				   transaction finishes */
105 	u64 bytes_reserved;	/* total bytes the allocator has reserved for
106 				   current allocations */
107 	u64 bytes_may_use;	/* number of bytes that may be used for
108 				   delalloc/allocations */
109 	u64 bytes_readonly;	/* total bytes that are read only */
110 	u64 bytes_zone_unusable;	/* total bytes that are unusable until
111 					   resetting the device zone */
112 
113 	u64 max_extent_size;	/* This will hold the maximum extent size of
114 				   the space info if we had an ENOSPC in the
115 				   allocator. */
116 	/* Chunk size in bytes */
117 	u64 chunk_size;
118 
119 	/*
120 	 * Once a block group drops below this threshold (percents) we'll
121 	 * schedule it for reclaim.
122 	 */
123 	int bg_reclaim_threshold;
124 
125 	int clamp;		/* Used to scale our threshold for preemptive
126 				   flushing. The value is >> clamp, so turns
127 				   out to be a 2^clamp divisor. */
128 
129 	unsigned int full:1;	/* indicates that we cannot allocate any more
130 				   chunks for this space */
131 	unsigned int chunk_alloc:1;	/* set if we are allocating a chunk */
132 
133 	unsigned int flush:1;		/* set if we are trying to make space */
134 
135 	unsigned int force_alloc;	/* set if we need to force a chunk
136 					   alloc for this space */
137 
138 	u64 disk_used;		/* total bytes used on disk */
139 	u64 disk_total;		/* total bytes on disk, takes mirrors into
140 				   account */
141 
142 	u64 flags;
143 
144 	struct list_head list;
145 	/* Protected by the spinlock 'lock'. */
146 	struct list_head ro_bgs;
147 	struct list_head priority_tickets;
148 	struct list_head tickets;
149 
150 	/*
151 	 * Size of space that needs to be reclaimed in order to satisfy pending
152 	 * tickets
153 	 */
154 	u64 reclaim_size;
155 
156 	/*
157 	 * tickets_id just indicates the next ticket will be handled, so note
158 	 * it's not stored per ticket.
159 	 */
160 	u64 tickets_id;
161 
162 	struct rw_semaphore groups_sem;
163 	/* for block groups in our same type */
164 	struct list_head block_groups[BTRFS_NR_RAID_TYPES];
165 
166 	struct kobject kobj;
167 	struct kobject *block_group_kobjs[BTRFS_NR_RAID_TYPES];
168 };
169 
170 struct reserve_ticket {
171 	u64 bytes;
172 	int error;
173 	bool steal;
174 	struct list_head list;
175 	wait_queue_head_t wait;
176 };
177 
178 static inline bool btrfs_mixed_space_info(struct btrfs_space_info *space_info)
179 {
180 	return ((space_info->flags & BTRFS_BLOCK_GROUP_METADATA) &&
181 		(space_info->flags & BTRFS_BLOCK_GROUP_DATA));
182 }
183 
184 /*
185  *
186  * Declare a helper function to detect underflow of various space info members
187  */
188 #define DECLARE_SPACE_INFO_UPDATE(name, trace_name)			\
189 static inline void							\
190 btrfs_space_info_update_##name(struct btrfs_fs_info *fs_info,		\
191 			       struct btrfs_space_info *sinfo,		\
192 			       s64 bytes)				\
193 {									\
194 	const u64 abs_bytes = (bytes < 0) ? -bytes : bytes;		\
195 	lockdep_assert_held(&sinfo->lock);				\
196 	trace_update_##name(fs_info, sinfo, sinfo->name, bytes);	\
197 	trace_btrfs_space_reservation(fs_info, trace_name,		\
198 				      sinfo->flags, abs_bytes,		\
199 				      bytes > 0);			\
200 	if (bytes < 0 && sinfo->name < -bytes) {			\
201 		WARN_ON(1);						\
202 		sinfo->name = 0;					\
203 		return;							\
204 	}								\
205 	sinfo->name += bytes;						\
206 }
207 
208 DECLARE_SPACE_INFO_UPDATE(bytes_may_use, "space_info");
209 DECLARE_SPACE_INFO_UPDATE(bytes_pinned, "pinned");
210 
211 int btrfs_init_space_info(struct btrfs_fs_info *fs_info);
212 void btrfs_add_bg_to_space_info(struct btrfs_fs_info *info,
213 				struct btrfs_block_group *block_group);
214 void btrfs_update_space_info_chunk_size(struct btrfs_space_info *space_info,
215 					u64 chunk_size);
216 struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info,
217 					       u64 flags);
218 u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info,
219 			  bool may_use_included);
220 void btrfs_clear_space_info_full(struct btrfs_fs_info *info);
221 void btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
222 			   struct btrfs_space_info *info, u64 bytes,
223 			   int dump_block_groups);
224 int btrfs_reserve_metadata_bytes(struct btrfs_fs_info *fs_info,
225 				 struct btrfs_space_info *space_info,
226 				 u64 orig_bytes,
227 				 enum btrfs_reserve_flush_enum flush);
228 void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info,
229 				struct btrfs_space_info *space_info);
230 int btrfs_can_overcommit(struct btrfs_fs_info *fs_info,
231 			 struct btrfs_space_info *space_info, u64 bytes,
232 			 enum btrfs_reserve_flush_enum flush);
233 
234 static inline void btrfs_space_info_free_bytes_may_use(
235 				struct btrfs_fs_info *fs_info,
236 				struct btrfs_space_info *space_info,
237 				u64 num_bytes)
238 {
239 	spin_lock(&space_info->lock);
240 	btrfs_space_info_update_bytes_may_use(fs_info, space_info, -num_bytes);
241 	btrfs_try_granting_tickets(fs_info, space_info);
242 	spin_unlock(&space_info->lock);
243 }
244 int btrfs_reserve_data_bytes(struct btrfs_fs_info *fs_info, u64 bytes,
245 			     enum btrfs_reserve_flush_enum flush);
246 void btrfs_dump_space_info_for_trans_abort(struct btrfs_fs_info *fs_info);
247 void btrfs_init_async_reclaim_work(struct btrfs_fs_info *fs_info);
248 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo);
249 
250 #endif /* BTRFS_SPACE_INFO_H */
251