xref: /linux/fs/f2fs/gc.h (revision cdd30ebb1b9f36159d66f088b61aee264e649d7a)
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 /* GC sleep parameters for zoned deivces */
19 #define DEF_GC_THREAD_MIN_SLEEP_TIME_ZONED	10
20 #define DEF_GC_THREAD_MAX_SLEEP_TIME_ZONED	20
21 #define DEF_GC_THREAD_NOGC_SLEEP_TIME_ZONED	60000
22 
23 /* choose candidates from sections which has age of more than 7 days */
24 #define DEF_GC_THREAD_AGE_THRESHOLD		(60 * 60 * 24 * 7)
25 #define DEF_GC_THREAD_CANDIDATE_RATIO		20	/* select 20% oldest sections as candidates */
26 #define DEF_GC_THREAD_MAX_CANDIDATE_COUNT	10	/* select at most 10 sections as candidates */
27 #define DEF_GC_THREAD_AGE_WEIGHT		60	/* age weight */
28 #define DEF_GC_THREAD_VALID_THRESH_RATIO	95	/* do not GC over 95% valid block ratio for one time GC */
29 #define DEFAULT_ACCURACY_CLASS			10000	/* accuracy class */
30 
31 #define LIMIT_INVALID_BLOCK	40 /* percentage over total user space */
32 #define LIMIT_FREE_BLOCK	40 /* percentage over invalid + free space */
33 
34 #define LIMIT_NO_ZONED_GC	60 /* percentage over total user space of no gc for zoned devices */
35 #define LIMIT_BOOST_ZONED_GC	25 /* percentage over total user space of boosted gc for zoned devices */
36 #define DEF_MIGRATION_WINDOW_GRANULARITY_ZONED	3
37 #define BOOST_GC_MULTIPLE	5
38 #define ZONED_PIN_SEC_REQUIRED_COUNT	1
39 
40 #define DEF_GC_FAILED_PINNED_FILES	2048
41 #define MAX_GC_FAILED_PINNED_FILES	USHRT_MAX
42 
43 /* Search max. number of dirty segments to select a victim segment */
44 #define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */
45 
46 #define NR_GC_CHECKPOINT_SECS (3)	/* data/node/dentry sections */
47 
48 struct f2fs_gc_kthread {
49 	struct task_struct *f2fs_gc_task;
50 	wait_queue_head_t gc_wait_queue_head;
51 
52 	/* for gc sleep time */
53 	unsigned int urgent_sleep_time;
54 	unsigned int min_sleep_time;
55 	unsigned int max_sleep_time;
56 	unsigned int no_gc_sleep_time;
57 
58 	/* for changing gc mode */
59 	bool gc_wake;
60 
61 	/* for GC_MERGE mount option */
62 	wait_queue_head_t fggc_wq;		/*
63 						 * caller of f2fs_balance_fs()
64 						 * will wait on this wait queue.
65 						 */
66 
67 	/* for gc control for zoned devices */
68 	unsigned int no_zoned_gc_percent;
69 	unsigned int boost_zoned_gc_percent;
70 	unsigned int valid_thresh_ratio;
71 };
72 
73 struct gc_inode_list {
74 	struct list_head ilist;
75 	struct radix_tree_root iroot;
76 };
77 
78 struct victim_entry {
79 	struct rb_node rb_node;		/* rb node located in rb-tree */
80 	unsigned long long mtime;	/* mtime of section */
81 	unsigned int segno;		/* segment No. */
82 	struct list_head list;
83 };
84 
85 /*
86  * inline functions
87  */
88 
89 /*
90  * On a Zoned device zone-capacity can be less than zone-size and if
91  * zone-capacity is not aligned to f2fs segment size(2MB), then the segment
92  * starting just before zone-capacity has some blocks spanning across the
93  * zone-capacity, these blocks are not usable.
94  * Such spanning segments can be in free list so calculate the sum of usable
95  * blocks in currently free segments including normal and spanning segments.
96  */
97 static inline block_t free_segs_blk_count_zoned(struct f2fs_sb_info *sbi)
98 {
99 	block_t free_seg_blks = 0;
100 	struct free_segmap_info *free_i = FREE_I(sbi);
101 	int j;
102 
103 	spin_lock(&free_i->segmap_lock);
104 	for (j = 0; j < MAIN_SEGS(sbi); j++)
105 		if (!test_bit(j, free_i->free_segmap))
106 			free_seg_blks += f2fs_usable_blks_in_seg(sbi, j);
107 	spin_unlock(&free_i->segmap_lock);
108 
109 	return free_seg_blks;
110 }
111 
112 static inline block_t free_segs_blk_count(struct f2fs_sb_info *sbi)
113 {
114 	if (f2fs_sb_has_blkzoned(sbi))
115 		return free_segs_blk_count_zoned(sbi);
116 
117 	return SEGS_TO_BLKS(sbi, free_segments(sbi));
118 }
119 
120 static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
121 {
122 	block_t free_blks, ovp_blks;
123 
124 	free_blks = free_segs_blk_count(sbi);
125 	ovp_blks = SEGS_TO_BLKS(sbi, overprovision_segments(sbi));
126 
127 	if (free_blks < ovp_blks)
128 		return 0;
129 
130 	return free_blks - ovp_blks;
131 }
132 
133 static inline block_t limit_invalid_user_blocks(block_t user_block_count)
134 {
135 	return (long)(user_block_count * LIMIT_INVALID_BLOCK) / 100;
136 }
137 
138 static inline block_t limit_free_user_blocks(block_t reclaimable_user_blocks)
139 {
140 	return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
141 }
142 
143 static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
144 							unsigned int *wait)
145 {
146 	unsigned int min_time = gc_th->min_sleep_time;
147 	unsigned int max_time = gc_th->max_sleep_time;
148 
149 	if (*wait == gc_th->no_gc_sleep_time)
150 		return;
151 
152 	if ((long long)*wait + (long long)min_time > (long long)max_time)
153 		*wait = max_time;
154 	else
155 		*wait += min_time;
156 }
157 
158 static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th,
159 							unsigned int *wait)
160 {
161 	unsigned int min_time = gc_th->min_sleep_time;
162 
163 	if (*wait == gc_th->no_gc_sleep_time)
164 		*wait = gc_th->max_sleep_time;
165 
166 	if ((long long)*wait - (long long)min_time < (long long)min_time)
167 		*wait = min_time;
168 	else
169 		*wait -= min_time;
170 }
171 
172 static inline bool has_enough_free_blocks(struct f2fs_sb_info *sbi,
173 						unsigned int limit_perc)
174 {
175 	return free_sections(sbi) > ((sbi->total_sections * limit_perc) / 100);
176 }
177 
178 static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
179 {
180 	block_t user_block_count = sbi->user_block_count;
181 	block_t invalid_user_blocks = user_block_count -
182 		written_block_count(sbi);
183 	/*
184 	 * Background GC is triggered with the following conditions.
185 	 * 1. There are a number of invalid blocks.
186 	 * 2. There is not enough free space.
187 	 */
188 	return (invalid_user_blocks >
189 			limit_invalid_user_blocks(user_block_count) &&
190 		free_user_blocks(sbi) <
191 			limit_free_user_blocks(invalid_user_blocks));
192 }
193 
194 static inline bool need_to_boost_gc(struct f2fs_sb_info *sbi)
195 {
196 	if (f2fs_sb_has_blkzoned(sbi))
197 		return !has_enough_free_blocks(sbi, LIMIT_BOOST_ZONED_GC);
198 	return has_enough_invalid_blocks(sbi);
199 }
200