linux/fs/f2fs/gc.h
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   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
  30/* Search max. number of dirty segments to select a victim segment */
  31#define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */
  32
  33struct f2fs_gc_kthread {
  34        struct task_struct *f2fs_gc_task;
  35        wait_queue_head_t gc_wait_queue_head;
  36
  37        /* for gc sleep time */
  38        unsigned int urgent_sleep_time;
  39        unsigned int min_sleep_time;
  40        unsigned int max_sleep_time;
  41        unsigned int no_gc_sleep_time;
  42
  43        /* for changing gc mode */
  44        unsigned int gc_wake;
  45};
  46
  47struct gc_inode_list {
  48        struct list_head ilist;
  49        struct radix_tree_root iroot;
  50};
  51
  52struct victim_info {
  53        unsigned long long mtime;       /* mtime of section */
  54        unsigned int segno;             /* section No. */
  55};
  56
  57struct victim_entry {
  58        struct rb_node rb_node;         /* rb node located in rb-tree */
  59        union {
  60                struct {
  61                        unsigned long long mtime;       /* mtime of section */
  62                        unsigned int segno;             /* segment No. */
  63                };
  64                struct victim_info vi;  /* victim info */
  65        };
  66        struct list_head list;
  67};
  68
  69/*
  70 * inline functions
  71 */
  72
  73/*
  74 * On a Zoned device zone-capacity can be less than zone-size and if
  75 * zone-capacity is not aligned to f2fs segment size(2MB), then the segment
  76 * starting just before zone-capacity has some blocks spanning across the
  77 * zone-capacity, these blocks are not usable.
  78 * Such spanning segments can be in free list so calculate the sum of usable
  79 * blocks in currently free segments including normal and spanning segments.
  80 */
  81static inline block_t free_segs_blk_count_zoned(struct f2fs_sb_info *sbi)
  82{
  83        block_t free_seg_blks = 0;
  84        struct free_segmap_info *free_i = FREE_I(sbi);
  85        int j;
  86
  87        spin_lock(&free_i->segmap_lock);
  88        for (j = 0; j < MAIN_SEGS(sbi); j++)
  89                if (!test_bit(j, free_i->free_segmap))
  90                        free_seg_blks += f2fs_usable_blks_in_seg(sbi, j);
  91        spin_unlock(&free_i->segmap_lock);
  92
  93        return free_seg_blks;
  94}
  95
  96static inline block_t free_segs_blk_count(struct f2fs_sb_info *sbi)
  97{
  98        if (f2fs_sb_has_blkzoned(sbi))
  99                return free_segs_blk_count_zoned(sbi);
 100
 101        return free_segments(sbi) << sbi->log_blocks_per_seg;
 102}
 103
 104static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
 105{
 106        block_t free_blks, ovp_blks;
 107
 108        free_blks = free_segs_blk_count(sbi);
 109        ovp_blks = overprovision_segments(sbi) << sbi->log_blocks_per_seg;
 110
 111        if (free_blks < ovp_blks)
 112                return 0;
 113
 114        return free_blks - ovp_blks;
 115}
 116
 117static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
 118{
 119        return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100;
 120}
 121
 122static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi)
 123{
 124        block_t reclaimable_user_blocks = sbi->user_block_count -
 125                written_block_count(sbi);
 126        return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
 127}
 128
 129static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
 130                                                        unsigned int *wait)
 131{
 132        unsigned int min_time = gc_th->min_sleep_time;
 133        unsigned int max_time = gc_th->max_sleep_time;
 134
 135        if (*wait == gc_th->no_gc_sleep_time)
 136                return;
 137
 138        if ((long long)*wait + (long long)min_time > (long long)max_time)
 139                *wait = max_time;
 140        else
 141                *wait += min_time;
 142}
 143
 144static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th,
 145                                                        unsigned int *wait)
 146{
 147        unsigned int min_time = gc_th->min_sleep_time;
 148
 149        if (*wait == gc_th->no_gc_sleep_time)
 150                *wait = gc_th->max_sleep_time;
 151
 152        if ((long long)*wait - (long long)min_time < (long long)min_time)
 153                *wait = min_time;
 154        else
 155                *wait -= min_time;
 156}
 157
 158static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
 159{
 160        block_t invalid_user_blocks = sbi->user_block_count -
 161                                        written_block_count(sbi);
 162        /*
 163         * Background GC is triggered with the following conditions.
 164         * 1. There are a number of invalid blocks.
 165         * 2. There is not enough free space.
 166         */
 167        if (invalid_user_blocks > limit_invalid_user_blocks(sbi) &&
 168                        free_user_blocks(sbi) < limit_free_user_blocks(sbi))
 169                return true;
 170        return false;
 171}
 172