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-rw-r--r--fs/f2fs/gc.h117
1 files changed, 117 insertions, 0 deletions
diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
new file mode 100644
index 00000000000..b026d9354cc
--- /dev/null
+++ b/fs/f2fs/gc.h
@@ -0,0 +1,117 @@
+/*
+ * 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_NAME "f2fs_gc_task"
+#define GC_THREAD_MIN_WB_PAGES 1 /*
+ * a threshold to determine
+ * whether IO subsystem is idle
+ * or not
+ */
+#define GC_THREAD_MIN_SLEEP_TIME 10000 /* milliseconds */
+#define GC_THREAD_MAX_SLEEP_TIME 30000
+#define GC_THREAD_NOGC_SLEEP_TIME 10000
+#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 MAX_VICTIM_SEARCH 20
+
+enum {
+ GC_NONE = 0,
+ GC_ERROR,
+ GC_OK,
+ GC_NEXT,
+ GC_BLOCKED,
+ GC_DONE,
+};
+
+struct f2fs_gc_kthread {
+ struct task_struct *f2fs_gc_task;
+ wait_queue_head_t gc_wait_queue_head;
+};
+
+struct inode_entry {
+ struct list_head list;
+ struct inode *inode;
+};
+
+/*
+ * 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 long increase_sleep_time(long wait)
+{
+ wait += GC_THREAD_MIN_SLEEP_TIME;
+ if (wait > GC_THREAD_MAX_SLEEP_TIME)
+ wait = GC_THREAD_MAX_SLEEP_TIME;
+ return wait;
+}
+
+static inline long decrease_sleep_time(long wait)
+{
+ wait -= GC_THREAD_MIN_SLEEP_TIME;
+ if (wait <= GC_THREAD_MIN_SLEEP_TIME)
+ wait = GC_THREAD_MIN_SLEEP_TIME;
+ return wait;
+}
+
+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 condition.
+ * 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]);
+}
+
+static inline bool should_do_checkpoint(struct f2fs_sb_info *sbi)
+{
+ unsigned int pages_per_sec = sbi->segs_per_sec *
+ (1 << sbi->log_blocks_per_seg);
+ int node_secs = ((get_pages(sbi, F2FS_DIRTY_NODES) + pages_per_sec - 1)
+ >> sbi->log_blocks_per_seg) / sbi->segs_per_sec;
+ int dent_secs = ((get_pages(sbi, F2FS_DIRTY_DENTS) + pages_per_sec - 1)
+ >> sbi->log_blocks_per_seg) / sbi->segs_per_sec;
+ return free_sections(sbi) <= (node_secs + 2 * dent_secs + 2);
+}