| /* |
| * fs/f2fs/gc.h |
| * |
| * Copyright (c) 2012 Samsung Electronics Co., Ltd. |
| * http://www.samsung.com/ |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| #define GC_THREAD_MIN_WB_PAGES 1 /* |
| * a threshold to determine |
| * whether IO subsystem is idle |
| * or not |
| */ |
| #define DEF_GC_THREAD_MIN_SLEEP_TIME 30000 /* milliseconds */ |
| #define DEF_GC_THREAD_MAX_SLEEP_TIME 60000 |
| #define DEF_GC_THREAD_NOGC_SLEEP_TIME 300000 /* wait 5 min */ |
| #define LIMIT_INVALID_BLOCK 40 /* percentage over total user space */ |
| #define LIMIT_FREE_BLOCK 40 /* percentage over invalid + free space */ |
| |
| /* Search max. number of dirty segments to select a victim segment */ |
| #define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */ |
| |
| struct f2fs_gc_kthread { |
| struct task_struct *f2fs_gc_task; |
| wait_queue_head_t gc_wait_queue_head; |
| |
| /* for gc sleep time */ |
| unsigned int min_sleep_time; |
| unsigned int max_sleep_time; |
| unsigned int no_gc_sleep_time; |
| |
| /* for changing gc mode */ |
| unsigned int gc_idle; |
| }; |
| |
| struct gc_inode_list { |
| struct list_head ilist; |
| struct radix_tree_root iroot; |
| }; |
| |
| extern struct kmem_cache *inode_entry_slab; |
| |
| /* |
| * inline functions |
| */ |
| static inline block_t free_user_blocks(struct f2fs_sb_info *sbi) |
| { |
| if (free_segments(sbi) < overprovision_segments(sbi)) |
| return 0; |
| else |
| return (free_segments(sbi) - overprovision_segments(sbi)) |
| << sbi->log_blocks_per_seg; |
| } |
| |
| static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi) |
| { |
| return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100; |
| } |
| |
| static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi) |
| { |
| block_t reclaimable_user_blocks = sbi->user_block_count - |
| written_block_count(sbi); |
| return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100; |
| } |
| |
| static inline void increase_sleep_time(struct f2fs_gc_kthread *gc_th, |
| long *wait) |
| { |
| if (*wait == gc_th->no_gc_sleep_time) |
| return; |
| |
| *wait += gc_th->min_sleep_time; |
| if (*wait > gc_th->max_sleep_time) |
| *wait = gc_th->max_sleep_time; |
| } |
| |
| static inline void decrease_sleep_time(struct f2fs_gc_kthread *gc_th, |
| long *wait) |
| { |
| if (*wait == gc_th->no_gc_sleep_time) |
| *wait = gc_th->max_sleep_time; |
| |
| *wait -= gc_th->min_sleep_time; |
| if (*wait <= gc_th->min_sleep_time) |
| *wait = gc_th->min_sleep_time; |
| } |
| |
| static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi) |
| { |
| block_t invalid_user_blocks = sbi->user_block_count - |
| written_block_count(sbi); |
| /* |
| * Background GC is triggered with the following conditions. |
| * 1. There are a number of invalid blocks. |
| * 2. There is not enough free space. |
| */ |
| if (invalid_user_blocks > limit_invalid_user_blocks(sbi) && |
| free_user_blocks(sbi) < limit_free_user_blocks(sbi)) |
| return true; |
| return false; |
| } |
| |
| static inline int is_idle(struct f2fs_sb_info *sbi) |
| { |
| struct block_device *bdev = sbi->sb->s_bdev; |
| struct request_queue *q = bdev_get_queue(bdev); |
| struct request_list *rl = &q->root_rl; |
| return !(rl->count[BLK_RW_SYNC]) && !(rl->count[BLK_RW_ASYNC]); |
| } |