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
 25struct 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
 39struct gc_inode_list {
 40	struct list_head ilist;
 41	struct radix_tree_root iroot;
 42};
 43
 44/*
 45 * inline functions
 46 */
 47static 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
 56static 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
 61static 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
 68static 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
 83static 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
 97static 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}