gc.h

  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/* GC sleep parameters for zoned deivces */
 19#define DEF_GC_THREAD_MIN_SLEEP_TIME_ZONED	10
 20#define DEF_GC_THREAD_MAX_SLEEP_TIME_ZONED	20
 21#define DEF_GC_THREAD_NOGC_SLEEP_TIME_ZONED	60000
 22
 23/* choose candidates from sections which has age of more than 7 days */
 24#define DEF_GC_THREAD_AGE_THRESHOLD		(60 * 60 * 24 * 7)
 25#define DEF_GC_THREAD_CANDIDATE_RATIO		20	/* select 20% oldest sections as candidates */
 26#define DEF_GC_THREAD_MAX_CANDIDATE_COUNT	10	/* select at most 10 sections as candidates */
 27#define DEF_GC_THREAD_AGE_WEIGHT		60	/* age weight */
 28#define DEF_GC_THREAD_VALID_THRESH_RATIO	80	/* do not GC over 80% valid block ratio for one time GC */
 29#define DEFAULT_ACCURACY_CLASS			10000	/* accuracy class */
 30
 31#define LIMIT_INVALID_BLOCK	40 /* percentage over total user space */
 32#define LIMIT_FREE_BLOCK	40 /* percentage over invalid + free space */
 33
 34#define LIMIT_NO_ZONED_GC	60 /* percentage over total user space of no gc for zoned devices */
 35#define LIMIT_BOOST_ZONED_GC	25 /* percentage over total user space of boosted gc for zoned devices */
 36#define DEF_MIGRATION_WINDOW_GRANULARITY_ZONED	3
 37#define BOOST_GC_MULTIPLE	5
 38#define ZONED_PIN_SEC_REQUIRED_COUNT	1
 39
 40#define DEF_GC_FAILED_PINNED_FILES	2048
 41#define MAX_GC_FAILED_PINNED_FILES	USHRT_MAX
 42
 43/* Search max. number of dirty segments to select a victim segment */
 44#define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */
 45
 46#define NR_GC_CHECKPOINT_SECS (3)	/* data/node/dentry sections */
 47
 48struct f2fs_gc_kthread {
 49	struct task_struct *f2fs_gc_task;
 50	wait_queue_head_t gc_wait_queue_head;
 51
 52	/* for gc sleep time */
 53	unsigned int urgent_sleep_time;
 54	unsigned int min_sleep_time;
 55	unsigned int max_sleep_time;
 56	unsigned int no_gc_sleep_time;
 57
 58	/* for changing gc mode */
 59	bool gc_wake;
 60
 61	/* for GC_MERGE mount option */
 62	wait_queue_head_t fggc_wq;		/*
 63						 * caller of f2fs_balance_fs()
 64						 * will wait on this wait queue.
 65						 */
 66
 67	/* for gc control for zoned devices */
 68	unsigned int no_zoned_gc_percent;
 69	unsigned int boost_zoned_gc_percent;
 70	unsigned int valid_thresh_ratio;
 71	unsigned int boost_gc_multiple;
 72	unsigned int boost_gc_greedy;
 73};
 74
 75struct gc_inode_list {
 76	struct list_head ilist;
 77	struct radix_tree_root iroot;
 78};
 79
 80struct victim_entry {
 81	struct rb_node rb_node;		/* rb node located in rb-tree */
 82	unsigned long long mtime;	/* mtime of section */
 83	unsigned int segno;		/* segment No. */
 84	struct list_head list;
 85};
 86
 87/*
 88 * inline functions
 89 */
 90
 91/*
 92 * On a Zoned device zone-capacity can be less than zone-size and if
 93 * zone-capacity is not aligned to f2fs segment size(2MB), then the segment
 94 * starting just before zone-capacity has some blocks spanning across the
 95 * zone-capacity, these blocks are not usable.
 96 * Such spanning segments can be in free list so calculate the sum of usable
 97 * blocks in currently free segments including normal and spanning segments.
 98 */
 99static inline block_t free_segs_blk_count_zoned(struct f2fs_sb_info *sbi)
100{
101	block_t free_seg_blks = 0;
102	struct free_segmap_info *free_i = FREE_I(sbi);
103	int j;
104
105	spin_lock(&free_i->segmap_lock);
106	for (j = 0; j < MAIN_SEGS(sbi); j++)
107		if (!test_bit(j, free_i->free_segmap))
108			free_seg_blks += f2fs_usable_blks_in_seg(sbi, j);
109	spin_unlock(&free_i->segmap_lock);
110
111	return free_seg_blks;
112}
113
114static inline block_t free_segs_blk_count(struct f2fs_sb_info *sbi)
115{
116	if (f2fs_sb_has_blkzoned(sbi))
117		return free_segs_blk_count_zoned(sbi);
118
119	return SEGS_TO_BLKS(sbi, free_segments(sbi));
120}
121
122static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
123{
124	block_t free_blks, ovp_blks;
125
126	free_blks = free_segs_blk_count(sbi);
127	ovp_blks = SEGS_TO_BLKS(sbi, overprovision_segments(sbi));
128
129	if (free_blks < ovp_blks)
130		return 0;
131
132	return free_blks - ovp_blks;
133}
134
135static inline block_t limit_invalid_user_blocks(block_t user_block_count)
136{
137	return (long)(user_block_count * LIMIT_INVALID_BLOCK) / 100;
138}
139
140static inline block_t limit_free_user_blocks(block_t reclaimable_user_blocks)
141{
142	return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
143}
144
145static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
146							unsigned int *wait)
147{
148	unsigned int min_time = gc_th->min_sleep_time;
149	unsigned int max_time = gc_th->max_sleep_time;
150
151	if (*wait == gc_th->no_gc_sleep_time)
152		return;
153
154	if ((long long)*wait + (long long)min_time > (long long)max_time)
155		*wait = max_time;
156	else
157		*wait += min_time;
158}
159
160static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th,
161							unsigned int *wait)
162{
163	unsigned int min_time = gc_th->min_sleep_time;
164
165	if (*wait == gc_th->no_gc_sleep_time)
166		*wait = gc_th->max_sleep_time;
167
168	if ((long long)*wait - (long long)min_time < (long long)min_time)
169		*wait = min_time;
170	else
171		*wait -= min_time;
172}
173
174static inline bool has_enough_free_blocks(struct f2fs_sb_info *sbi,
175						unsigned int limit_perc)
176{
177	return free_sections(sbi) > ((sbi->total_sections * limit_perc) / 100);
178}
179
180static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
181{
182	block_t user_block_count = sbi->user_block_count;
183	block_t invalid_user_blocks = user_block_count -
184		written_block_count(sbi);
185	/*
186	 * Background GC is triggered with the following conditions.
187	 * 1. There are a number of invalid blocks.
188	 * 2. There is not enough free space.
189	 */
190	return (invalid_user_blocks >
191			limit_invalid_user_blocks(user_block_count) &&
192		free_user_blocks(sbi) <
193			limit_free_user_blocks(invalid_user_blocks));
194}
195
196static inline bool need_to_boost_gc(struct f2fs_sb_info *sbi)
197{
198	if (f2fs_sb_has_blkzoned(sbi))
199		return !has_enough_free_blocks(sbi,
200				sbi->gc_thread->boost_zoned_gc_percent);
201	return has_enough_invalid_blocks(sbi);
202}