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#define MAX_GC_FAILED_PINNED_FILES	USHRT_MAX
30
31/* Search max. number of dirty segments to select a victim segment */
32#define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */
33
34#define NR_GC_CHECKPOINT_SECS (3)	/* data/node/dentry sections */
35
36struct f2fs_gc_kthread {
37	struct task_struct *f2fs_gc_task;
38	wait_queue_head_t gc_wait_queue_head;
39
40	/* for gc sleep time */
41	unsigned int urgent_sleep_time;
42	unsigned int min_sleep_time;
43	unsigned int max_sleep_time;
44	unsigned int no_gc_sleep_time;
45
46	/* for changing gc mode */
47	bool gc_wake;
48
49	/* for GC_MERGE mount option */
50	wait_queue_head_t fggc_wq;		/*
51						 * caller of f2fs_balance_fs()
52						 * will wait on this wait queue.
53						 */
54};
55
56struct gc_inode_list {
57	struct list_head ilist;
58	struct radix_tree_root iroot;
59};
60
61struct victim_entry {
62	struct rb_node rb_node;		/* rb node located in rb-tree */
63	unsigned long long mtime;	/* mtime of section */
64	unsigned int segno;		/* segment No. */
65	struct list_head list;
66};
67
68/*
69 * inline functions
70 */
71
72/*
73 * On a Zoned device zone-capacity can be less than zone-size and if
74 * zone-capacity is not aligned to f2fs segment size(2MB), then the segment
75 * starting just before zone-capacity has some blocks spanning across the
76 * zone-capacity, these blocks are not usable.
77 * Such spanning segments can be in free list so calculate the sum of usable
78 * blocks in currently free segments including normal and spanning segments.
79 */
80static inline block_t free_segs_blk_count_zoned(struct f2fs_sb_info *sbi)
81{
82	block_t free_seg_blks = 0;
83	struct free_segmap_info *free_i = FREE_I(sbi);
84	int j;
85
86	spin_lock(&free_i->segmap_lock);
87	for (j = 0; j < MAIN_SEGS(sbi); j++)
88		if (!test_bit(j, free_i->free_segmap))
89			free_seg_blks += f2fs_usable_blks_in_seg(sbi, j);
90	spin_unlock(&free_i->segmap_lock);
91
92	return free_seg_blks;
93}
94
95static inline block_t free_segs_blk_count(struct f2fs_sb_info *sbi)
96{
97	if (f2fs_sb_has_blkzoned(sbi))
98		return free_segs_blk_count_zoned(sbi);
99
100	return SEGS_TO_BLKS(sbi, free_segments(sbi));
101}
102
103static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
104{
105	block_t free_blks, ovp_blks;
106
107	free_blks = free_segs_blk_count(sbi);
108	ovp_blks = SEGS_TO_BLKS(sbi, overprovision_segments(sbi));
109
110	if (free_blks < ovp_blks)
111		return 0;
112
113	return free_blks - ovp_blks;
114}
115
116static inline block_t limit_invalid_user_blocks(block_t user_block_count)
117{
118	return (long)(user_block_count * LIMIT_INVALID_BLOCK) / 100;
119}
120
121static inline block_t limit_free_user_blocks(block_t reclaimable_user_blocks)
122{
123	return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
124}
125
126static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
127							unsigned int *wait)
128{
129	unsigned int min_time = gc_th->min_sleep_time;
130	unsigned int max_time = gc_th->max_sleep_time;
131
132	if (*wait == gc_th->no_gc_sleep_time)
133		return;
134
135	if ((long long)*wait + (long long)min_time > (long long)max_time)
136		*wait = max_time;
137	else
138		*wait += min_time;
139}
140
141static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th,
142							unsigned int *wait)
143{
144	unsigned int min_time = gc_th->min_sleep_time;
145
146	if (*wait == gc_th->no_gc_sleep_time)
147		*wait = gc_th->max_sleep_time;
148
149	if ((long long)*wait - (long long)min_time < (long long)min_time)
150		*wait = min_time;
151	else
152		*wait -= min_time;
153}
154
155static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
156{
157	block_t user_block_count = sbi->user_block_count;
158	block_t invalid_user_blocks = user_block_count -
159		written_block_count(sbi);
160	/*
161	 * Background GC is triggered with the following conditions.
162	 * 1. There are a number of invalid blocks.
163	 * 2. There is not enough free space.
164	 */
165	return (invalid_user_blocks >
166			limit_invalid_user_blocks(user_block_count) &&
167		free_user_blocks(sbi) <
168			limit_free_user_blocks(invalid_user_blocks));
169}
170