f2fs: change GC bitmaps to apply the section granularity

This patch removes a bitmap for victim segments selected by foreground GC, and
modifies the other bitmap for victim segments selected by background GC.

1) foreground GC bitmap
 : We don't need to manage this, since we just only one previous victim section
   number instead of the whole victim history.
   The f2fs uses the victim section number in order not to allocate currently
   GC'ed section to current active logs.

2) background GC bitmap
 : This bitmap is used to avoid selecting victims repeatedly by background GCs.
   In addition, the victims are able to be selected by foreground GCs, since
   there is no need to read victim blocks during foreground GCs.

   By the fact that the foreground GC reclaims segments in a section unit, it'd
   be better to manage this bitmap based on the section granularity.

Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index fea9245d4774..994bb7bd7b70 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -10,6 +10,7 @@
  */
 /* constant macro */
 #define NULL_SEGNO			((unsigned int)(~0))
+#define NULL_SECNO			((unsigned int)(~0))
 
 /* V: Logical segment # in volume, R: Relative segment # in main area */
 #define GET_L2R_SEGNO(free_i, segno)	(segno - free_i->start_segno)
@@ -214,7 +215,7 @@ struct dirty_seglist_info {
 	unsigned long *dirty_segmap[NR_DIRTY_TYPE];
 	struct mutex seglist_lock;		/* lock for segment bitmaps */
 	int nr_dirty[NR_DIRTY_TYPE];		/* # of dirty segments */
-	unsigned long *victim_segmap[2];	/* BG_GC, FG_GC */
+	unsigned long *victim_secmap;		/* background GC victims */
 };
 
 /* victim selection function for cleaning and SSR */
@@ -616,3 +617,10 @@ static inline block_t sum_blk_addr(struct f2fs_sb_info *sbi, int base, int type)
 		le32_to_cpu(F2FS_CKPT(sbi)->cp_pack_total_block_count)
 				- (base + 1) + type;
 }
+
+static inline bool sec_usage_check(struct f2fs_sb_info *sbi, unsigned int secno)
+{
+	if (IS_CURSEC(sbi, secno) || (sbi->cur_victim_sec == secno))
+		return true;
+	return false;
+}