f2fs: fix count of seg_freed to make sec_freed correct

When sbi->segs_per_sec > 1, and if some segno has 0 valid blocks before
gc starts, do_garbage_collect will skip counting seg_freed++, and this
will cause seg_freed < sbi->segs_per_sec and finally skip sec_freed++.
Signed-off-by: NYunlong Song <yunlong.song@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/gc.c

@@ -1140,9 +1140,9 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
 					GET_SUM_BLOCK(sbi, segno));
 		f2fs_put_page(sum_page, 0);
 
-		if (get_valid_blocks(sbi, segno, false) == 0 ||
-				!PageUptodate(sum_page) ||
-				unlikely(f2fs_cp_error(sbi)))
+		if (get_valid_blocks(sbi, segno, false) == 0)
+			goto freed;
+		if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
 			goto next;
 
 		sum = page_address(sum_page);
@@ -1170,6 +1170,7 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
 
 		stat_inc_seg_count(sbi, type, gc_type);
 
+freed:
 		if (gc_type == FG_GC &&
 				get_valid_blocks(sbi, segno, false) == 0)
 			seg_freed++;