118 lines
3.2 KiB
C
118 lines
3.2 KiB
C
/*
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* fs/f2fs/gc.h
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*
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* Copyright (c) 2012 Samsung Electronics Co., Ltd.
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* http://www.samsung.com/
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#define GC_THREAD_NAME "f2fs_gc_task"
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#define GC_THREAD_MIN_WB_PAGES 1 /*
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* a threshold to determine
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* whether IO subsystem is idle
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* or not
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*/
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#define GC_THREAD_MIN_SLEEP_TIME 10000 /* milliseconds */
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#define GC_THREAD_MAX_SLEEP_TIME 30000
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#define GC_THREAD_NOGC_SLEEP_TIME 10000
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#define LIMIT_INVALID_BLOCK 40 /* percentage over total user space */
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#define LIMIT_FREE_BLOCK 40 /* percentage over invalid + free space */
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/* Search max. number of dirty segments to select a victim segment */
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#define MAX_VICTIM_SEARCH 20
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enum {
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GC_NONE = 0,
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GC_ERROR,
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GC_OK,
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GC_NEXT,
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GC_BLOCKED,
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GC_DONE,
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};
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struct f2fs_gc_kthread {
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struct task_struct *f2fs_gc_task;
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wait_queue_head_t gc_wait_queue_head;
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};
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struct inode_entry {
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struct list_head list;
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struct inode *inode;
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};
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/*
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* inline functions
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*/
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static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
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{
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if (free_segments(sbi) < overprovision_segments(sbi))
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return 0;
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else
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return (free_segments(sbi) - overprovision_segments(sbi))
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<< sbi->log_blocks_per_seg;
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}
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static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
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{
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return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100;
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}
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static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi)
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{
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block_t reclaimable_user_blocks = sbi->user_block_count -
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written_block_count(sbi);
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return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
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}
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static inline long increase_sleep_time(long wait)
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{
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wait += GC_THREAD_MIN_SLEEP_TIME;
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if (wait > GC_THREAD_MAX_SLEEP_TIME)
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wait = GC_THREAD_MAX_SLEEP_TIME;
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return wait;
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}
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static inline long decrease_sleep_time(long wait)
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{
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wait -= GC_THREAD_MIN_SLEEP_TIME;
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if (wait <= GC_THREAD_MIN_SLEEP_TIME)
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wait = GC_THREAD_MIN_SLEEP_TIME;
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return wait;
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}
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static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
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{
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block_t invalid_user_blocks = sbi->user_block_count -
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written_block_count(sbi);
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/*
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* Background GC is triggered with the following condition.
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* 1. There are a number of invalid blocks.
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* 2. There is not enough free space.
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*/
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if (invalid_user_blocks > limit_invalid_user_blocks(sbi) &&
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free_user_blocks(sbi) < limit_free_user_blocks(sbi))
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return true;
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return false;
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}
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static inline int is_idle(struct f2fs_sb_info *sbi)
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{
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struct block_device *bdev = sbi->sb->s_bdev;
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struct request_queue *q = bdev_get_queue(bdev);
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struct request_list *rl = &q->root_rl;
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return !(rl->count[BLK_RW_SYNC]) && !(rl->count[BLK_RW_ASYNC]);
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}
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static inline bool should_do_checkpoint(struct f2fs_sb_info *sbi)
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{
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unsigned int pages_per_sec = sbi->segs_per_sec *
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(1 << sbi->log_blocks_per_seg);
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int node_secs = ((get_pages(sbi, F2FS_DIRTY_NODES) + pages_per_sec - 1)
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>> sbi->log_blocks_per_seg) / sbi->segs_per_sec;
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int dent_secs = ((get_pages(sbi, F2FS_DIRTY_DENTS) + pages_per_sec - 1)
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>> sbi->log_blocks_per_seg) / sbi->segs_per_sec;
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return free_sections(sbi) <= (node_secs + 2 * dent_secs + 2);
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}
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