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 80 /* do not GC over 80% 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
48struct 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 unsigned int boost_gc_multiple;
72 unsigned int boost_gc_greedy;
73};
74
75struct gc_inode_list {
76 struct list_head ilist;
77 struct radix_tree_root iroot;
78};
79
80struct victim_entry {
81 struct rb_node rb_node; /* rb node located in rb-tree */
82 unsigned long long mtime; /* mtime of section */
83 unsigned int segno; /* segment No. */
84 struct list_head list;
85};
86
87/*
88 * inline functions
89 */
90
91/*
92 * On a Zoned device zone-capacity can be less than zone-size and if
93 * zone-capacity is not aligned to f2fs segment size(2MB), then the segment
94 * starting just before zone-capacity has some blocks spanning across the
95 * zone-capacity, these blocks are not usable.
96 * Such spanning segments can be in free list so calculate the sum of usable
97 * blocks in currently free segments including normal and spanning segments.
98 */
99static inline block_t free_segs_blk_count_zoned(struct f2fs_sb_info *sbi)
100{
101 block_t free_seg_blks = 0;
102 struct free_segmap_info *free_i = FREE_I(sbi);
103 int j;
104
105 spin_lock(lock: &free_i->segmap_lock);
106 for (j = 0; j < MAIN_SEGS(sbi); j++)
107 if (!test_bit(j, free_i->free_segmap))
108 free_seg_blks += f2fs_usable_blks_in_seg(sbi, segno: j);
109 spin_unlock(lock: &free_i->segmap_lock);
110
111 return free_seg_blks;
112}
113
114static inline block_t free_segs_blk_count(struct f2fs_sb_info *sbi)
115{
116 if (f2fs_sb_has_blkzoned(sbi))
117 return free_segs_blk_count_zoned(sbi);
118
119 return SEGS_TO_BLKS(sbi, free_segments(sbi));
120}
121
122static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
123{
124 block_t free_blks, ovp_blks;
125
126 free_blks = free_segs_blk_count(sbi);
127 ovp_blks = SEGS_TO_BLKS(sbi, overprovision_segments(sbi));
128
129 if (free_blks < ovp_blks)
130 return 0;
131
132 return free_blks - ovp_blks;
133}
134
135static inline block_t limit_invalid_user_blocks(block_t user_block_count)
136{
137 return (long)(user_block_count * LIMIT_INVALID_BLOCK) / 100;
138}
139
140static inline block_t limit_free_user_blocks(block_t reclaimable_user_blocks)
141{
142 return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
143}
144
145static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
146 unsigned int *wait)
147{
148 unsigned int min_time = gc_th->min_sleep_time;
149 unsigned int max_time = gc_th->max_sleep_time;
150
151 if (*wait == gc_th->no_gc_sleep_time)
152 return;
153
154 if ((long long)*wait + (long long)min_time > (long long)max_time)
155 *wait = max_time;
156 else
157 *wait += min_time;
158}
159
160static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th,
161 unsigned int *wait)
162{
163 unsigned int min_time = gc_th->min_sleep_time;
164
165 if (*wait == gc_th->no_gc_sleep_time)
166 *wait = gc_th->max_sleep_time;
167
168 if ((long long)*wait - (long long)min_time < (long long)min_time)
169 *wait = min_time;
170 else
171 *wait -= min_time;
172}
173
174static inline bool has_enough_free_blocks(struct f2fs_sb_info *sbi,
175 unsigned int limit_perc)
176{
177 return free_sections(sbi) > ((sbi->total_sections * limit_perc) / 100);
178}
179
180static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
181{
182 block_t user_block_count = sbi->user_block_count;
183 block_t invalid_user_blocks = user_block_count -
184 written_block_count(sbi);
185 /*
186 * Background GC is triggered with the following conditions.
187 * 1. There are a number of invalid blocks.
188 * 2. There is not enough free space.
189 */
190 return (invalid_user_blocks >
191 limit_invalid_user_blocks(user_block_count) &&
192 free_user_blocks(sbi) <
193 limit_free_user_blocks(reclaimable_user_blocks: invalid_user_blocks));
194}
195
196static inline bool need_to_boost_gc(struct f2fs_sb_info *sbi)
197{
198 if (f2fs_sb_has_blkzoned(sbi))
199 return !has_enough_free_blocks(sbi,
200 limit_perc: sbi->gc_thread->boost_zoned_gc_percent);
201 return has_enough_invalid_blocks(sbi);
202}
203

source code of linux/fs/f2fs/gc.h