xref: /linux/fs/f2fs/gc.h (revision dcabb06bf127b3e0d3fbc94a2b65dd56c2725851)
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 	unsigned int gc_wake;
45 };
46 
47 struct gc_inode_list {
48 	struct list_head ilist;
49 	struct radix_tree_root iroot;
50 };
51 
52 struct victim_info {
53 	unsigned long long mtime;	/* mtime of section */
54 	unsigned int segno;		/* section No. */
55 };
56 
57 struct victim_entry {
58 	struct rb_node rb_node;		/* rb node located in rb-tree */
59 	union {
60 		struct {
61 			unsigned long long mtime;	/* mtime of section */
62 			unsigned int segno;		/* segment No. */
63 		};
64 		struct victim_info vi;	/* victim info */
65 	};
66 	struct list_head list;
67 };
68 
69 /*
70  * inline functions
71  */
72 
73 /*
74  * On a Zoned device zone-capacity can be less than zone-size and if
75  * zone-capacity is not aligned to f2fs segment size(2MB), then the segment
76  * starting just before zone-capacity has some blocks spanning across the
77  * zone-capacity, these blocks are not usable.
78  * Such spanning segments can be in free list so calculate the sum of usable
79  * blocks in currently free segments including normal and spanning segments.
80  */
81 static inline block_t free_segs_blk_count_zoned(struct f2fs_sb_info *sbi)
82 {
83 	block_t free_seg_blks = 0;
84 	struct free_segmap_info *free_i = FREE_I(sbi);
85 	int j;
86 
87 	spin_lock(&free_i->segmap_lock);
88 	for (j = 0; j < MAIN_SEGS(sbi); j++)
89 		if (!test_bit(j, free_i->free_segmap))
90 			free_seg_blks += f2fs_usable_blks_in_seg(sbi, j);
91 	spin_unlock(&free_i->segmap_lock);
92 
93 	return free_seg_blks;
94 }
95 
96 static inline block_t free_segs_blk_count(struct f2fs_sb_info *sbi)
97 {
98 	if (f2fs_sb_has_blkzoned(sbi))
99 		return free_segs_blk_count_zoned(sbi);
100 
101 	return free_segments(sbi) << sbi->log_blocks_per_seg;
102 }
103 
104 static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
105 {
106 	block_t free_blks, ovp_blks;
107 
108 	free_blks = free_segs_blk_count(sbi);
109 	ovp_blks = overprovision_segments(sbi) << sbi->log_blocks_per_seg;
110 
111 	if (free_blks < ovp_blks)
112 		return 0;
113 
114 	return free_blks - ovp_blks;
115 }
116 
117 static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
118 {
119 	return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100;
120 }
121 
122 static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi)
123 {
124 	block_t reclaimable_user_blocks = sbi->user_block_count -
125 		written_block_count(sbi);
126 	return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
127 }
128 
129 static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
130 							unsigned int *wait)
131 {
132 	unsigned int min_time = gc_th->min_sleep_time;
133 	unsigned int max_time = gc_th->max_sleep_time;
134 
135 	if (*wait == gc_th->no_gc_sleep_time)
136 		return;
137 
138 	if ((long long)*wait + (long long)min_time > (long long)max_time)
139 		*wait = max_time;
140 	else
141 		*wait += min_time;
142 }
143 
144 static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th,
145 							unsigned int *wait)
146 {
147 	unsigned int min_time = gc_th->min_sleep_time;
148 
149 	if (*wait == gc_th->no_gc_sleep_time)
150 		*wait = gc_th->max_sleep_time;
151 
152 	if ((long long)*wait - (long long)min_time < (long long)min_time)
153 		*wait = min_time;
154 	else
155 		*wait -= min_time;
156 }
157 
158 static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
159 {
160 	block_t invalid_user_blocks = sbi->user_block_count -
161 					written_block_count(sbi);
162 	/*
163 	 * Background GC is triggered with the following conditions.
164 	 * 1. There are a number of invalid blocks.
165 	 * 2. There is not enough free space.
166 	 */
167 	if (invalid_user_blocks > limit_invalid_user_blocks(sbi) &&
168 			free_user_blocks(sbi) < limit_free_user_blocks(sbi))
169 		return true;
170 	return false;
171 }
172