root/fs/f2fs/gc.h

INCLUDED FROM

DEFINITIONS

1. free_user_blocks
2. limit_invalid_user_blocks
3. limit_free_user_blocks
4. increase_sleep_time
5. decrease_sleep_time
6. has_enough_invalid_blocks

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