xref: /openbmc/linux/fs/f2fs/gc.h (revision 1bffcea4)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * fs/f2fs/gc.h
4  *
5  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
6  *             http://www.samsung.com/
7  */
8 #define GC_THREAD_MIN_WB_PAGES		1	/*
9 						 * a threshold to determine
10 						 * whether IO subsystem is idle
11 						 * or not
12 						 */
13 #define DEF_GC_THREAD_URGENT_SLEEP_TIME	500	/* 500 ms */
14 #define DEF_GC_THREAD_MIN_SLEEP_TIME	30000	/* milliseconds */
15 #define DEF_GC_THREAD_MAX_SLEEP_TIME	60000
16 #define DEF_GC_THREAD_NOGC_SLEEP_TIME	300000	/* wait 5 min */
17 
18 /* choose candidates from sections which has age of more than 7 days */
19 #define DEF_GC_THREAD_AGE_THRESHOLD		(60 * 60 * 24 * 7)
20 #define DEF_GC_THREAD_CANDIDATE_RATIO		20	/* select 20% oldest sections as candidates */
21 #define DEF_GC_THREAD_MAX_CANDIDATE_COUNT	10	/* select at most 10 sections as candidates */
22 #define DEF_GC_THREAD_AGE_WEIGHT		60	/* age weight */
23 #define DEFAULT_ACCURACY_CLASS			10000	/* accuracy class */
24 
25 #define LIMIT_INVALID_BLOCK	40 /* percentage over total user space */
26 #define LIMIT_FREE_BLOCK	40 /* percentage over invalid + free space */
27 
28 #define DEF_GC_FAILED_PINNED_FILES	2048
29 
30 /* Search max. number of dirty segments to select a victim segment */
31 #define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */
32 
33 struct f2fs_gc_kthread {
34 	struct task_struct *f2fs_gc_task;
35 	wait_queue_head_t gc_wait_queue_head;
36 
37 	/* for gc sleep time */
38 	unsigned int urgent_sleep_time;
39 	unsigned int min_sleep_time;
40 	unsigned int max_sleep_time;
41 	unsigned int no_gc_sleep_time;
42 
43 	/* for changing gc mode */
44 	bool gc_wake;
45 
46 	/* for GC_MERGE mount option */
47 	wait_queue_head_t fggc_wq;		/*
48 						 * caller of f2fs_balance_fs()
49 						 * will wait on this wait queue.
50 						 */
51 };
52 
53 struct gc_inode_list {
54 	struct list_head ilist;
55 	struct radix_tree_root iroot;
56 };
57 
58 struct victim_info {
59 	unsigned long long mtime;	/* mtime of section */
60 	unsigned int segno;		/* section No. */
61 };
62 
63 struct victim_entry {
64 	struct rb_node rb_node;		/* rb node located in rb-tree */
65 	union {
66 		struct {
67 			unsigned long long mtime;	/* mtime of section */
68 			unsigned int segno;		/* segment No. */
69 		};
70 		struct victim_info vi;	/* victim info */
71 	};
72 	struct list_head list;
73 };
74 
75 /*
76  * inline functions
77  */
78 
79 /*
80  * On a Zoned device zone-capacity can be less than zone-size and if
81  * zone-capacity is not aligned to f2fs segment size(2MB), then the segment
82  * starting just before zone-capacity has some blocks spanning across the
83  * zone-capacity, these blocks are not usable.
84  * Such spanning segments can be in free list so calculate the sum of usable
85  * blocks in currently free segments including normal and spanning segments.
86  */
87 static inline block_t free_segs_blk_count_zoned(struct f2fs_sb_info *sbi)
88 {
89 	block_t free_seg_blks = 0;
90 	struct free_segmap_info *free_i = FREE_I(sbi);
91 	int j;
92 
93 	spin_lock(&free_i->segmap_lock);
94 	for (j = 0; j < MAIN_SEGS(sbi); j++)
95 		if (!test_bit(j, free_i->free_segmap))
96 			free_seg_blks += f2fs_usable_blks_in_seg(sbi, j);
97 	spin_unlock(&free_i->segmap_lock);
98 
99 	return free_seg_blks;
100 }
101 
102 static inline block_t free_segs_blk_count(struct f2fs_sb_info *sbi)
103 {
104 	if (f2fs_sb_has_blkzoned(sbi))
105 		return free_segs_blk_count_zoned(sbi);
106 
107 	return free_segments(sbi) << sbi->log_blocks_per_seg;
108 }
109 
110 static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
111 {
112 	block_t free_blks, ovp_blks;
113 
114 	free_blks = free_segs_blk_count(sbi);
115 	ovp_blks = overprovision_segments(sbi) << sbi->log_blocks_per_seg;
116 
117 	if (free_blks < ovp_blks)
118 		return 0;
119 
120 	return free_blks - ovp_blks;
121 }
122 
123 static inline block_t limit_invalid_user_blocks(block_t user_block_count)
124 {
125 	return (long)(user_block_count * LIMIT_INVALID_BLOCK) / 100;
126 }
127 
128 static inline block_t limit_free_user_blocks(block_t reclaimable_user_blocks)
129 {
130 	return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
131 }
132 
133 static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
134 							unsigned int *wait)
135 {
136 	unsigned int min_time = gc_th->min_sleep_time;
137 	unsigned int max_time = gc_th->max_sleep_time;
138 
139 	if (*wait == gc_th->no_gc_sleep_time)
140 		return;
141 
142 	if ((long long)*wait + (long long)min_time > (long long)max_time)
143 		*wait = max_time;
144 	else
145 		*wait += min_time;
146 }
147 
148 static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th,
149 							unsigned int *wait)
150 {
151 	unsigned int min_time = gc_th->min_sleep_time;
152 
153 	if (*wait == gc_th->no_gc_sleep_time)
154 		*wait = gc_th->max_sleep_time;
155 
156 	if ((long long)*wait - (long long)min_time < (long long)min_time)
157 		*wait = min_time;
158 	else
159 		*wait -= min_time;
160 }
161 
162 static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
163 {
164 	block_t user_block_count = sbi->user_block_count;
165 	block_t invalid_user_blocks = user_block_count -
166 		written_block_count(sbi);
167 	/*
168 	 * Background GC is triggered with the following conditions.
169 	 * 1. There are a number of invalid blocks.
170 	 * 2. There is not enough free space.
171 	 */
172 	return (invalid_user_blocks >
173 			limit_invalid_user_blocks(user_block_count) &&
174 		free_user_blocks(sbi) <
175 			limit_free_user_blocks(invalid_user_blocks));
176 }
177