f2fs: reclaim prefree segments periodically
Previously, f2fs postpones reclaiming prefree segments into free segments
as much as possible.
However, if user writes and deletes a bunch of data without any sync or fsync
calls, some flash storages can suffer from garbage collections.
So, this patch adds the reclaiming codes to f2fs_write_node_pages and background
GC thread.
If there are a lot of prefree segments, let's do checkpoint so that f2fs
submits discard commands for the prefree regions to the flash storage.
Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 7f94d78..abe7094 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -14,6 +14,8 @@
#define NULL_SEGNO ((unsigned int)(~0))
#define NULL_SECNO ((unsigned int)(~0))
+#define DEF_RECLAIM_PREFREE_SEGMENTS 100 /* 200MB of prefree segments */
+
/* L: Logical segment # in volume, R: Relative segment # in main area */
#define GET_L2R_SEGNO(free_i, segno) (segno - free_i->start_segno)
#define GET_R2L_SEGNO(free_i, segno) (segno + free_i->start_segno)
@@ -472,6 +474,11 @@
reserved_sections(sbi)));
}
+static inline bool excess_prefree_segs(struct f2fs_sb_info *sbi)
+{
+ return (prefree_segments(sbi) > SM_I(sbi)->rec_prefree_segments);
+}
+
static inline int utilization(struct f2fs_sb_info *sbi)
{
return div_u64((u64)valid_user_blocks(sbi) * 100, sbi->user_block_count);
