xref: /openbmc/linux/fs/f2fs/gc.h (revision 20e2fc42)
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 #define LIMIT_INVALID_BLOCK	40 /* percentage over total user space */
18 #define LIMIT_FREE_BLOCK	40 /* percentage over invalid + free space */
19 
20 #define DEF_GC_FAILED_PINNED_FILES	2048
21 
22 /* Search max. number of dirty segments to select a victim segment */
23 #define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */
24 
25 struct f2fs_gc_kthread {
26 	struct task_struct *f2fs_gc_task;
27 	wait_queue_head_t gc_wait_queue_head;
28 
29 	/* for gc sleep time */
30 	unsigned int urgent_sleep_time;
31 	unsigned int min_sleep_time;
32 	unsigned int max_sleep_time;
33 	unsigned int no_gc_sleep_time;
34 
35 	/* for changing gc mode */
36 	unsigned int gc_wake;
37 };
38 
39 struct gc_inode_list {
40 	struct list_head ilist;
41 	struct radix_tree_root iroot;
42 };
43 
44 /*
45  * inline functions
46  */
47 static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
48 {
49 	if (free_segments(sbi) < overprovision_segments(sbi))
50 		return 0;
51 	else
52 		return (free_segments(sbi) - overprovision_segments(sbi))
53 			<< sbi->log_blocks_per_seg;
54 }
55 
56 static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
57 {
58 	return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100;
59 }
60 
61 static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi)
62 {
63 	block_t reclaimable_user_blocks = sbi->user_block_count -
64 		written_block_count(sbi);
65 	return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
66 }
67 
68 static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
69 							unsigned int *wait)
70 {
71 	unsigned int min_time = gc_th->min_sleep_time;
72 	unsigned int max_time = gc_th->max_sleep_time;
73 
74 	if (*wait == gc_th->no_gc_sleep_time)
75 		return;
76 
77 	if ((long long)*wait + (long long)min_time > (long long)max_time)
78 		*wait = max_time;
79 	else
80 		*wait += min_time;
81 }
82 
83 static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th,
84 							unsigned int *wait)
85 {
86 	unsigned int min_time = gc_th->min_sleep_time;
87 
88 	if (*wait == gc_th->no_gc_sleep_time)
89 		*wait = gc_th->max_sleep_time;
90 
91 	if ((long long)*wait - (long long)min_time < (long long)min_time)
92 		*wait = min_time;
93 	else
94 		*wait -= min_time;
95 }
96 
97 static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
98 {
99 	block_t invalid_user_blocks = sbi->user_block_count -
100 					written_block_count(sbi);
101 	/*
102 	 * Background GC is triggered with the following conditions.
103 	 * 1. There are a number of invalid blocks.
104 	 * 2. There is not enough free space.
105 	 */
106 	if (invalid_user_blocks > limit_invalid_user_blocks(sbi) &&
107 			free_user_blocks(sbi) < limit_free_user_blocks(sbi))
108 		return true;
109 	return false;
110 }
111