f2fs: fix to account gc stats correctly

As reported, status debugfs entry shows inconsistent GC stats as below:

GC calls: 6008 (BG: 6161)
  - data segments : 3053 (BG: 3053)
  - node segments : 2955 (BG: 2955)

Total GC calls is larger than BGGC calls, the reason is:
- f2fs_stat_info.call_count accounts total migrated section count
by f2fs_gc()
- f2fs_stat_info.bg_gc accounts total call times of f2fs_gc() from
background gc_thread

Another issue is gc_foreground_calls sysfs entry shows total GC call
count rather than FGGC call count.

This patch changes as below for fix:
- account GC calls and migrated segment count separately
- support to account migrated section count if it enables large section
mode
- fix to show correct value in gc_foreground_calls sysfs entry

Fixes: fc7100ea2a52 ("f2fs: Add f2fs stats to sysfs")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 7 insertions, 6 deletions

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 01effd3fcb6c..68c3250fb3d2 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -121,8 +121,8 @@ static int gc_thread_func(void *data)
 		else
 			increase_sleep_time(gc_th, &wait_ms);
 do_gc:
-		if (!foreground)
-			stat_inc_bggc_count(sbi->stat_info);
+		stat_inc_gc_call_count(sbi, foreground ?
+					FOREGROUND : BACKGROUND);
 
 		sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC;
 
@@ -1685,6 +1685,7 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
 	int seg_freed = 0, migrated = 0;
 	unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
 						SUM_TYPE_DATA : SUM_TYPE_NODE;
+	unsigned char data_type = (type == SUM_TYPE_DATA) ? DATA : NODE;
 	int submitted = 0;
 
 	if (__is_large_section(sbi))
@@ -1766,7 +1767,7 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
 							segno, gc_type,
 							force_migrate);
 
-		stat_inc_seg_count(sbi, type, gc_type);
+		stat_inc_gc_seg_count(sbi, data_type, gc_type);
 		sbi->gc_reclaimed_segs[sbi->gc_mode]++;
 		migrated++;
 
@@ -1783,12 +1784,12 @@ skip:
 	}
 
 	if (submitted)
-		f2fs_submit_merged_write(sbi,
-				(type == SUM_TYPE_NODE) ? NODE : DATA);
+		f2fs_submit_merged_write(sbi, data_type);
 
 	blk_finish_plug(&plug);
 
-	stat_inc_call_count(sbi->stat_info);
+	if (migrated)
+		stat_inc_gc_sec_count(sbi, data_type, gc_type);
 
 	return seg_freed;
 }