projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 0a8165d7 | 1 | /* |
| 7bc09003 JK |
2 | * fs/f2fs/gc.h |
| 3 | * | |
| 4 | * Copyright (c) 2012 Samsung Electronics Co., Ltd. | |
| 5 | * http://www.samsung.com/ | |
| 6 | * | |
| 7 | * This program is free software; you can redistribute it and/or modify | |
| 8 | * it under the terms of the GNU General Public License version 2 as | |
| 9 | * published by the Free Software Foundation. | |
| 10 | */ | |
| 11 | #define GC_THREAD_NAME "f2fs_gc_task" | |
| 12 | #define GC_THREAD_MIN_WB_PAGES 1 /* | |
| 13 | * a threshold to determine | |
| 14 | * whether IO subsystem is idle | |
| 15 | * or not | |
| 16 | */ | |
| 17 | #define GC_THREAD_MIN_SLEEP_TIME 10000 /* milliseconds */ | |
| 18 | #define GC_THREAD_MAX_SLEEP_TIME 30000 | |
| 19 | #define GC_THREAD_NOGC_SLEEP_TIME 10000 | |
| 20 | #define LIMIT_INVALID_BLOCK 40 /* percentage over total user space */ | |
| 21 | #define LIMIT_FREE_BLOCK 40 /* percentage over invalid + free space */ | |
| 22 | ||
| 23 | /* Search max. number of dirty segments to select a victim segment */ | |
| 24 | #define MAX_VICTIM_SEARCH 20 | |
| 25 | ||
| 26 | enum { | |
| 27 | GC_NONE = 0, | |
| 28 | GC_ERROR, | |
| 29 | GC_OK, | |
| 30 | GC_NEXT, | |
| 31 | GC_BLOCKED, | |
| 32 | GC_DONE, | |
| 33 | }; | |
| 34 | ||
| 35 | struct f2fs_gc_kthread { | |
| 36 | struct task_struct *f2fs_gc_task; | |
| 37 | wait_queue_head_t gc_wait_queue_head; | |
| 38 | }; | |
| 39 | ||
| 40 | struct inode_entry { | |
| 41 | struct list_head list; | |
| 42 | struct inode *inode; | |
| 43 | }; | |
| 44 | ||
| 0a8165d7 | 45 | /* |
| 7bc09003 JK |
46 | * inline functions |
| 47 | */ | |
| 48 | static inline block_t free_user_blocks(struct f2fs_sb_info *sbi) | |
| 49 | { | |
| 50 | if (free_segments(sbi) < overprovision_segments(sbi)) | |
| 51 | return 0; | |
| 52 | else | |
| 53 | return (free_segments(sbi) - overprovision_segments(sbi)) | |
| 54 | << sbi->log_blocks_per_seg; | |
| 55 | } | |
| 56 | ||
| 57 | static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi) | |
| 58 | { | |
| 59 | return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100; | |
| 60 | } | |
| 61 | ||
| 62 | static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi) | |
| 63 | { | |
| 64 | block_t reclaimable_user_blocks = sbi->user_block_count - | |
| 65 | written_block_count(sbi); | |
| 66 | return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100; | |
| 67 | } | |
| 68 | ||
| 69 | static inline long increase_sleep_time(long wait) | |
| 70 | { | |
| 71 | wait += GC_THREAD_MIN_SLEEP_TIME; | |
| 72 | if (wait > GC_THREAD_MAX_SLEEP_TIME) | |
| 73 | wait = GC_THREAD_MAX_SLEEP_TIME; | |
| 74 | return wait; | |
| 75 | } | |
| 76 | ||
| 77 | static inline long decrease_sleep_time(long wait) | |
| 78 | { | |
| 79 | wait -= GC_THREAD_MIN_SLEEP_TIME; | |
| 80 | if (wait <= GC_THREAD_MIN_SLEEP_TIME) | |
| 81 | wait = GC_THREAD_MIN_SLEEP_TIME; | |
| 82 | return wait; | |
| 83 | } | |
| 84 | ||
| 85 | static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi) | |
| 86 | { | |
| 87 | block_t invalid_user_blocks = sbi->user_block_count - | |
| 88 | written_block_count(sbi); | |
| 89 | /* | |
| 90 | * Background GC is triggered with the following condition. | |
| 91 | * 1. There are a number of invalid blocks. | |
| 92 | * 2. There is not enough free space. | |
| 93 | */ | |
| 94 | if (invalid_user_blocks > limit_invalid_user_blocks(sbi) && | |
| 95 | free_user_blocks(sbi) < limit_free_user_blocks(sbi)) | |
| 96 | return true; | |
| 97 | return false; | |
| 98 | } | |
| 99 | ||
| 100 | static inline int is_idle(struct f2fs_sb_info *sbi) | |
| 101 | { | |
| 102 | struct block_device *bdev = sbi->sb->s_bdev; | |
| 103 | struct request_queue *q = bdev_get_queue(bdev); | |
| 104 | struct request_list *rl = &q->root_rl; | |
| 105 | return !(rl->count[BLK_RW_SYNC]) && !(rl->count[BLK_RW_ASYNC]); | |
| 106 | } | |
| 107 | ||
| 108 | static inline bool should_do_checkpoint(struct f2fs_sb_info *sbi) | |
| 109 | { | |
| 110 | unsigned int pages_per_sec = sbi->segs_per_sec * | |
| 111 | (1 << sbi->log_blocks_per_seg); | |
| 112 | int node_secs = ((get_pages(sbi, F2FS_DIRTY_NODES) + pages_per_sec - 1) | |
| 113 | >> sbi->log_blocks_per_seg) / sbi->segs_per_sec; | |
| 114 | int dent_secs = ((get_pages(sbi, F2FS_DIRTY_DENTS) + pages_per_sec - 1) | |
| 115 | >> sbi->log_blocks_per_seg) / sbi->segs_per_sec; | |
| 116 | return free_sections(sbi) <= (node_secs + 2 * dent_secs + 2); | |
| 117 | } |