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 #define NR_GC_CHECKPOINT_SECS (3)	/* data/node/dentry sections */
34 
35 struct f2fs_gc_kthread {
36 	struct task_struct *f2fs_gc_task;
37 	wait_queue_head_t gc_wait_queue_head;
38 
39 	/* for gc sleep time */
40 	unsigned int urgent_sleep_time;
41 	unsigned int min_sleep_time;
42 	unsigned int max_sleep_time;
43 	unsigned int no_gc_sleep_time;
44 
45 	/* for changing gc mode */
46 	bool gc_wake;
47 
48 	/* for GC_MERGE mount option */
49 	wait_queue_head_t fggc_wq;		/*
50 						 * caller of f2fs_balance_fs()
51 						 * will wait on this wait queue.
52 						 */
53 };
54 
55 struct gc_inode_list {
56 	struct list_head ilist;
57 	struct radix_tree_root iroot;
58 };
59 
60 struct victim_entry {
61 	struct rb_node rb_node;		/* rb node located in rb-tree */
62 	unsigned long long mtime;	/* mtime of section */
63 	unsigned int segno;		/* segment No. */
64 	struct list_head list;
65 };
66 
67 /*
68  * inline functions
69  */
70 
71 /*
72  * On a Zoned device zone-capacity can be less than zone-size and if
73  * zone-capacity is not aligned to f2fs segment size(2MB), then the segment
74  * starting just before zone-capacity has some blocks spanning across the
75  * zone-capacity, these blocks are not usable.
76  * Such spanning segments can be in free list so calculate the sum of usable
77  * blocks in currently free segments including normal and spanning segments.
78  */
free_segs_blk_count_zoned(struct f2fs_sb_info * sbi)79 static inline block_t free_segs_blk_count_zoned(struct f2fs_sb_info *sbi)
80 {
81 	block_t free_seg_blks = 0;
82 	struct free_segmap_info *free_i = FREE_I(sbi);
83 	int j;
84 
85 	spin_lock(&free_i->segmap_lock);
86 	for (j = 0; j < MAIN_SEGS(sbi); j++)
87 		if (!test_bit(j, free_i->free_segmap))
88 			free_seg_blks += f2fs_usable_blks_in_seg(sbi, j);
89 	spin_unlock(&free_i->segmap_lock);
90 
91 	return free_seg_blks;
92 }
93 
free_segs_blk_count(struct f2fs_sb_info * sbi)94 static inline block_t free_segs_blk_count(struct f2fs_sb_info *sbi)
95 {
96 	if (f2fs_sb_has_blkzoned(sbi))
97 		return free_segs_blk_count_zoned(sbi);
98 
99 	return free_segments(sbi) << sbi->log_blocks_per_seg;
100 }
101 
free_user_blocks(struct f2fs_sb_info * sbi)102 static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
103 {
104 	block_t free_blks, ovp_blks;
105 
106 	free_blks = free_segs_blk_count(sbi);
107 	ovp_blks = overprovision_segments(sbi) << sbi->log_blocks_per_seg;
108 
109 	if (free_blks < ovp_blks)
110 		return 0;
111 
112 	return free_blks - ovp_blks;
113 }
114 
limit_invalid_user_blocks(block_t user_block_count)115 static inline block_t limit_invalid_user_blocks(block_t user_block_count)
116 {
117 	return (long)(user_block_count * LIMIT_INVALID_BLOCK) / 100;
118 }
119 
limit_free_user_blocks(block_t reclaimable_user_blocks)120 static inline block_t limit_free_user_blocks(block_t reclaimable_user_blocks)
121 {
122 	return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
123 }
124 
increase_sleep_time(struct f2fs_gc_kthread * gc_th,unsigned int * wait)125 static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
126 							unsigned int *wait)
127 {
128 	unsigned int min_time = gc_th->min_sleep_time;
129 	unsigned int max_time = gc_th->max_sleep_time;
130 
131 	if (*wait == gc_th->no_gc_sleep_time)
132 		return;
133 
134 	if ((long long)*wait + (long long)min_time > (long long)max_time)
135 		*wait = max_time;
136 	else
137 		*wait += min_time;
138 }
139 
decrease_sleep_time(struct f2fs_gc_kthread * gc_th,unsigned int * wait)140 static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th,
141 							unsigned int *wait)
142 {
143 	unsigned int min_time = gc_th->min_sleep_time;
144 
145 	if (*wait == gc_th->no_gc_sleep_time)
146 		*wait = gc_th->max_sleep_time;
147 
148 	if ((long long)*wait - (long long)min_time < (long long)min_time)
149 		*wait = min_time;
150 	else
151 		*wait -= min_time;
152 }
153 
has_enough_invalid_blocks(struct f2fs_sb_info * sbi)154 static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
155 {
156 	block_t user_block_count = sbi->user_block_count;
157 	block_t invalid_user_blocks = user_block_count -
158 		written_block_count(sbi);
159 	/*
160 	 * Background GC is triggered with the following conditions.
161 	 * 1. There are a number of invalid blocks.
162 	 * 2. There is not enough free space.
163 	 */
164 	return (invalid_user_blocks >
165 			limit_invalid_user_blocks(user_block_count) &&
166 		free_user_blocks(sbi) <
167 			limit_free_user_blocks(invalid_user_blocks));
168 }
169