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        /* for GC_MERGE mount option */
  47        wait_queue_head_t fggc_wq;              /*
  48                                                 * caller of f2fs_balance_fs()
  49                                                 * will wait on this wait queue.
  50                                                 */
  51};
  52
  53struct gc_inode_list {
  54        struct list_head ilist;
  55        struct radix_tree_root iroot;
  56};
  57
  58struct victim_info {
  59        unsigned long long mtime;       /* mtime of section */
  60        unsigned int segno;             /* section No. */
  61};
  62
  63struct victim_entry {
  64        struct rb_node rb_node;         /* rb node located in rb-tree */
  65        union {
  66                struct {
  67                        unsigned long long mtime;       /* mtime of section */
  68                        unsigned int segno;             /* segment No. */
  69                };
  70                struct victim_info vi;  /* victim info */
  71        };
  72        struct list_head list;
  73};
  74
  75/*
  76 * inline functions
  77 */
  78
  79/*
  80 * On a Zoned device zone-capacity can be less than zone-size and if
  81 * zone-capacity is not aligned to f2fs segment size(2MB), then the segment
  82 * starting just before zone-capacity has some blocks spanning across the
  83 * zone-capacity, these blocks are not usable.
  84 * Such spanning segments can be in free list so calculate the sum of usable
  85 * blocks in currently free segments including normal and spanning segments.
  86 */
  87static inline block_t free_segs_blk_count_zoned(struct f2fs_sb_info *sbi)
  88{
  89        block_t free_seg_blks = 0;
  90        struct free_segmap_info *free_i = FREE_I(sbi);
  91        int j;
  92
  93        spin_lock(&free_i->segmap_lock);
  94        for (j = 0; j < MAIN_SEGS(sbi); j++)
  95                if (!test_bit(j, free_i->free_segmap))
  96                        free_seg_blks += f2fs_usable_blks_in_seg(sbi, j);
  97        spin_unlock(&free_i->segmap_lock);
  98
  99        return free_seg_blks;
 100}
 101
 102static inline block_t free_segs_blk_count(struct f2fs_sb_info *sbi)
 103{
 104        if (f2fs_sb_has_blkzoned(sbi))
 105                return free_segs_blk_count_zoned(sbi);
 106
 107        return free_segments(sbi) << sbi->log_blocks_per_seg;
 108}
 109
 110static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
 111{
 112        block_t free_blks, ovp_blks;
 113
 114        free_blks = free_segs_blk_count(sbi);
 115        ovp_blks = overprovision_segments(sbi) << sbi->log_blocks_per_seg;
 116
 117        if (free_blks < ovp_blks)
 118                return 0;
 119
 120        return free_blks - ovp_blks;
 121}
 122
 123static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
 124{
 125        return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100;
 126}
 127
 128static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi)
 129{
 130        block_t reclaimable_user_blocks = sbi->user_block_count -
 131                written_block_count(sbi);
 132        return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
 133}
 134
 135static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th,
 136                                                        unsigned int *wait)
 137{
 138        unsigned int min_time = gc_th->min_sleep_time;
 139        unsigned int max_time = gc_th->max_sleep_time;
 140
 141        if (*wait == gc_th->no_gc_sleep_time)
 142                return;
 143
 144        if ((long long)*wait + (long long)min_time > (long long)max_time)
 145                *wait = max_time;
 146        else
 147                *wait += min_time;
 148}
 149
 150static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th,
 151                                                        unsigned int *wait)
 152{
 153        unsigned int min_time = gc_th->min_sleep_time;
 154
 155        if (*wait == gc_th->no_gc_sleep_time)
 156                *wait = gc_th->max_sleep_time;
 157
 158        if ((long long)*wait - (long long)min_time < (long long)min_time)
 159                *wait = min_time;
 160        else
 161                *wait -= min_time;
 162}
 163
 164static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
 165{
 166        block_t invalid_user_blocks = sbi->user_block_count -
 167                                        written_block_count(sbi);
 168        /*
 169         * Background GC is triggered with the following conditions.
 170         * 1. There are a number of invalid blocks.
 171         * 2. There is not enough free space.
 172         */
 173        if (invalid_user_blocks > limit_invalid_user_blocks(sbi) &&
 174                        free_user_blocks(sbi) < limit_free_user_blocks(sbi))
 175                return true;
 176        return false;
 177}
 178