xref: /linux/fs/f2fs/gc.h (revision 55f1b540d893da740a81200450014c45a8103f54)
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 
39 #define DEF_GC_FAILED_PINNED_FILES	2048
40 #define MAX_GC_FAILED_PINNED_FILES	USHRT_MAX
41 
42 /* Search max. number of dirty segments to select a victim segment */
43 #define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */
44 
45 #define NR_GC_CHECKPOINT_SECS (3)	/* data/node/dentry sections */
46 
47 struct f2fs_gc_kthread {
48 	struct task_struct *f2fs_gc_task;
49 	wait_queue_head_t gc_wait_queue_head;
50 
51 	/* for gc sleep time */
52 	unsigned int urgent_sleep_time;
53 	unsigned int min_sleep_time;
54 	unsigned int max_sleep_time;
55 	unsigned int no_gc_sleep_time;
56 
57 	/* for changing gc mode */
58 	bool gc_wake;
59 
60 	/* for GC_MERGE mount option */
61 	wait_queue_head_t fggc_wq;		/*
62 						 * caller of f2fs_balance_fs()
63 						 * will wait on this wait queue.
64 						 */
65 
66 	/* for gc control for zoned devices */
67 	unsigned int no_zoned_gc_percent;
68 	unsigned int boost_zoned_gc_percent;
69 	unsigned int valid_thresh_ratio;
70 };
71 
72 struct gc_inode_list {
73 	struct list_head ilist;
74 	struct radix_tree_root iroot;
75 };
76 
77 struct victim_entry {
78 	struct rb_node rb_node;		/* rb node located in rb-tree */
79 	unsigned long long mtime;	/* mtime of section */
80 	unsigned int segno;		/* segment No. */
81 	struct list_head list;
82 };
83 
84 /*
85  * inline functions
86  */
87 
88 /*
89  * On a Zoned device zone-capacity can be less than zone-size and if
90  * zone-capacity is not aligned to f2fs segment size(2MB), then the segment
91  * starting just before zone-capacity has some blocks spanning across the
92  * zone-capacity, these blocks are not usable.
93  * Such spanning segments can be in free list so calculate the sum of usable
94  * blocks in currently free segments including normal and spanning segments.
95  */
96 static inline block_t free_segs_blk_count_zoned(struct f2fs_sb_info *sbi)
97 {
98 	block_t free_seg_blks = 0;
99 	struct free_segmap_info *free_i = FREE_I(sbi);
100 	int j;
101 
102 	spin_lock(&free_i->segmap_lock);
103 	for (j = 0; j < MAIN_SEGS(sbi); j++)
104 		if (!test_bit(j, free_i->free_segmap))
105 			free_seg_blks += f2fs_usable_blks_in_seg(sbi, j);
106 	spin_unlock(&free_i->segmap_lock);
107 
108 	return free_seg_blks;
109 }
110 
111 static inline block_t free_segs_blk_count(struct f2fs_sb_info *sbi)
112 {
113 	if (f2fs_sb_has_blkzoned(sbi))
114 		return free_segs_blk_count_zoned(sbi);
115 
116 	return SEGS_TO_BLKS(sbi, free_segments(sbi));
117 }
118 
119 static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
120 {
121 	block_t free_blks, ovp_blks;
122 
123 	free_blks = free_segs_blk_count(sbi);
124 	ovp_blks = SEGS_TO_BLKS(sbi, overprovision_segments(sbi));
125 
126 	if (free_blks < ovp_blks)
127 		return 0;
128 
129 	return free_blks - ovp_blks;
130 }
131 
132 static inline block_t limit_invalid_user_blocks(block_t user_block_count)
133 {
134 	return (long)(user_block_count * LIMIT_INVALID_BLOCK) / 100;
135 }
136 
137 static inline block_t limit_free_user_blocks(block_t reclaimable_user_blocks)
138 {
139 	return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
140 }
141 
142 static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
143 							unsigned int *wait)
144 {
145 	unsigned int min_time = gc_th->min_sleep_time;
146 	unsigned int max_time = gc_th->max_sleep_time;
147 
148 	if (*wait == gc_th->no_gc_sleep_time)
149 		return;
150 
151 	if ((long long)*wait + (long long)min_time > (long long)max_time)
152 		*wait = max_time;
153 	else
154 		*wait += min_time;
155 }
156 
157 static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th,
158 							unsigned int *wait)
159 {
160 	unsigned int min_time = gc_th->min_sleep_time;
161 
162 	if (*wait == gc_th->no_gc_sleep_time)
163 		*wait = gc_th->max_sleep_time;
164 
165 	if ((long long)*wait - (long long)min_time < (long long)min_time)
166 		*wait = min_time;
167 	else
168 		*wait -= min_time;
169 }
170 
171 static inline bool has_enough_free_blocks(struct f2fs_sb_info *sbi,
172 						unsigned int limit_perc)
173 {
174 	return free_sections(sbi) > ((sbi->total_sections * limit_perc) / 100);
175 }
176 
177 static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
178 {
179 	block_t user_block_count = sbi->user_block_count;
180 	block_t invalid_user_blocks = user_block_count -
181 		written_block_count(sbi);
182 	/*
183 	 * Background GC is triggered with the following conditions.
184 	 * 1. There are a number of invalid blocks.
185 	 * 2. There is not enough free space.
186 	 */
187 	return (invalid_user_blocks >
188 			limit_invalid_user_blocks(user_block_count) &&
189 		free_user_blocks(sbi) <
190 			limit_free_user_blocks(invalid_user_blocks));
191 }
192 
193 static inline bool need_to_boost_gc(struct f2fs_sb_info *sbi)
194 {
195 	if (f2fs_sb_has_blkzoned(sbi))
196 		return !has_enough_free_blocks(sbi, LIMIT_BOOST_ZONED_GC);
197 	return has_enough_invalid_blocks(sbi);
198 }
199