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 /* for GC_MERGE mount option */
47 wait_queue_head_t fggc_wq; /*
48 * caller of f2fs_balance_fs()
49 * will wait on this wait queue.
50 */
51 };
52
53 struct gc_inode_list {
54 struct list_head ilist;
55 struct radix_tree_root iroot;
56 };
57
58 struct victim_info {
59 unsigned long long mtime; /* mtime of section */
60 unsigned int segno; /* section No. */
61 };
62
63 struct victim_entry {
64 struct rb_node rb_node; /* rb node located in rb-tree */
65 union {
66 struct {
67 unsigned long long mtime; /* mtime of section */
68 unsigned int segno; /* segment No. */
69 };
70 struct victim_info vi; /* victim info */
71 };
72 struct list_head list;
73 };
74
75 /*
76 * inline functions
77 */
78
79 /*
80 * On a Zoned device zone-capacity can be less than zone-size and if
81 * zone-capacity is not aligned to f2fs segment size(2MB), then the segment
82 * starting just before zone-capacity has some blocks spanning across the
83 * zone-capacity, these blocks are not usable.
84 * Such spanning segments can be in free list so calculate the sum of usable
85 * blocks in currently free segments including normal and spanning segments.
86 */
free_segs_blk_count_zoned(struct f2fs_sb_info * sbi)87 static inline block_t free_segs_blk_count_zoned(struct f2fs_sb_info *sbi)
88 {
89 block_t free_seg_blks = 0;
90 struct free_segmap_info *free_i = FREE_I(sbi);
91 int j;
92
93 spin_lock(&free_i->segmap_lock);
94 for (j = 0; j < MAIN_SEGS(sbi); j++)
95 if (!test_bit(j, free_i->free_segmap))
96 free_seg_blks += f2fs_usable_blks_in_seg(sbi, j);
97 spin_unlock(&free_i->segmap_lock);
98
99 return free_seg_blks;
100 }
101
free_segs_blk_count(struct f2fs_sb_info * sbi)102 static inline block_t free_segs_blk_count(struct f2fs_sb_info *sbi)
103 {
104 if (f2fs_sb_has_blkzoned(sbi))
105 return free_segs_blk_count_zoned(sbi);
106
107 return free_segments(sbi) << sbi->log_blocks_per_seg;
108 }
109
free_user_blocks(struct f2fs_sb_info * sbi)110 static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
111 {
112 block_t free_blks, ovp_blks;
113
114 free_blks = free_segs_blk_count(sbi);
115 ovp_blks = overprovision_segments(sbi) << sbi->log_blocks_per_seg;
116
117 if (free_blks < ovp_blks)
118 return 0;
119
120 return free_blks - ovp_blks;
121 }
122
limit_invalid_user_blocks(struct f2fs_sb_info * sbi)123 static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
124 {
125 return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100;
126 }
127
limit_free_user_blocks(struct f2fs_sb_info * sbi)128 static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi)
129 {
130 block_t reclaimable_user_blocks = sbi->user_block_count -
131 written_block_count(sbi);
132 return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
133 }
134
increase_sleep_time(struct f2fs_gc_kthread * gc_th,unsigned int * wait)135 static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
136 unsigned int *wait)
137 {
138 unsigned int min_time = gc_th->min_sleep_time;
139 unsigned int max_time = gc_th->max_sleep_time;
140
141 if (*wait == gc_th->no_gc_sleep_time)
142 return;
143
144 if ((long long)*wait + (long long)min_time > (long long)max_time)
145 *wait = max_time;
146 else
147 *wait += min_time;
148 }
149
decrease_sleep_time(struct f2fs_gc_kthread * gc_th,unsigned int * wait)150 static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th,
151 unsigned int *wait)
152 {
153 unsigned int min_time = gc_th->min_sleep_time;
154
155 if (*wait == gc_th->no_gc_sleep_time)
156 *wait = gc_th->max_sleep_time;
157
158 if ((long long)*wait - (long long)min_time < (long long)min_time)
159 *wait = min_time;
160 else
161 *wait -= min_time;
162 }
163
has_enough_invalid_blocks(struct f2fs_sb_info * sbi)164 static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
165 {
166 block_t invalid_user_blocks = sbi->user_block_count -
167 written_block_count(sbi);
168 /*
169 * Background GC is triggered with the following conditions.
170 * 1. There are a number of invalid blocks.
171 * 2. There is not enough free space.
172 */
173 if (invalid_user_blocks > limit_invalid_user_blocks(sbi) &&
174 free_user_blocks(sbi) < limit_free_user_blocks(sbi))
175 return true;
176 return false;
177 }
178