blob: 2c6a6bd0832244f4bb1e45b52cd41400e87fe363 [file] [log] [blame]
Jaegeuk Kim0a8165d2012-11-29 13:28:09 +09001/*
Jaegeuk Kim7bc09002012-11-02 17:13:01 +09002 * fs/f2fs/gc.h
3 *
4 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
5 * http://www.samsung.com/
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
Jaegeuk Kim7bc09002012-11-02 17:13:01 +090011#define GC_THREAD_MIN_WB_PAGES 1 /*
12 * a threshold to determine
13 * whether IO subsystem is idle
14 * or not
15 */
Jaegeuk Kim6cb968d2013-04-24 13:00:14 +090016#define GC_THREAD_MIN_SLEEP_TIME 30000 /* milliseconds */
17#define GC_THREAD_MAX_SLEEP_TIME 60000
18#define GC_THREAD_NOGC_SLEEP_TIME 300000 /* wait 5 min */
Jaegeuk Kim7bc09002012-11-02 17:13:01 +090019#define LIMIT_INVALID_BLOCK 40 /* percentage over total user space */
20#define LIMIT_FREE_BLOCK 40 /* percentage over invalid + free space */
21
22/* Search max. number of dirty segments to select a victim segment */
23#define MAX_VICTIM_SEARCH 20
24
Jaegeuk Kim7bc09002012-11-02 17:13:01 +090025struct f2fs_gc_kthread {
26 struct task_struct *f2fs_gc_task;
27 wait_queue_head_t gc_wait_queue_head;
28};
29
30struct inode_entry {
31 struct list_head list;
32 struct inode *inode;
33};
34
Jaegeuk Kim0a8165d2012-11-29 13:28:09 +090035/*
Jaegeuk Kim7bc09002012-11-02 17:13:01 +090036 * inline functions
37 */
38static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
39{
40 if (free_segments(sbi) < overprovision_segments(sbi))
41 return 0;
42 else
43 return (free_segments(sbi) - overprovision_segments(sbi))
44 << sbi->log_blocks_per_seg;
45}
46
47static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
48{
49 return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100;
50}
51
52static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi)
53{
54 block_t reclaimable_user_blocks = sbi->user_block_count -
55 written_block_count(sbi);
56 return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
57}
58
59static inline long increase_sleep_time(long wait)
60{
Jaegeuk Kim6cb968d2013-04-24 13:00:14 +090061 if (wait == GC_THREAD_NOGC_SLEEP_TIME)
62 return wait;
63
Jaegeuk Kim7bc09002012-11-02 17:13:01 +090064 wait += GC_THREAD_MIN_SLEEP_TIME;
65 if (wait > GC_THREAD_MAX_SLEEP_TIME)
66 wait = GC_THREAD_MAX_SLEEP_TIME;
67 return wait;
68}
69
70static inline long decrease_sleep_time(long wait)
71{
Jaegeuk Kim6cb968d2013-04-24 13:00:14 +090072 if (wait == GC_THREAD_NOGC_SLEEP_TIME)
73 wait = GC_THREAD_MAX_SLEEP_TIME;
74
Jaegeuk Kim7bc09002012-11-02 17:13:01 +090075 wait -= GC_THREAD_MIN_SLEEP_TIME;
76 if (wait <= GC_THREAD_MIN_SLEEP_TIME)
77 wait = GC_THREAD_MIN_SLEEP_TIME;
78 return wait;
79}
80
81static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
82{
83 block_t invalid_user_blocks = sbi->user_block_count -
84 written_block_count(sbi);
85 /*
86 * Background GC is triggered with the following condition.
87 * 1. There are a number of invalid blocks.
88 * 2. There is not enough free space.
89 */
90 if (invalid_user_blocks > limit_invalid_user_blocks(sbi) &&
91 free_user_blocks(sbi) < limit_free_user_blocks(sbi))
92 return true;
93 return false;
94}
95
96static inline int is_idle(struct f2fs_sb_info *sbi)
97{
98 struct block_device *bdev = sbi->sb->s_bdev;
99 struct request_queue *q = bdev_get_queue(bdev);
100 struct request_list *rl = &q->root_rl;
101 return !(rl->count[BLK_RW_SYNC]) && !(rl->count[BLK_RW_ASYNC]);
102}