Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / fs / f2fs / gc.h

diff --git a/kernel/fs/f2fs/gc.h b/kernel/fs/f2fs/gc.h
new file mode 100644 (file)
index 0000000..b4a65be
--- /dev/null
+++ b/kernel/fs/f2fs/gc.h
@@ -0,0 +1,110 @@
+/*
+ * 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;
+};
+
+/*
+ * 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]);
+}