f2fs: show counts of checkpoint in status

This patch shows the counts of checkpoint in f2fs' status.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index deb6035..757b77b 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -914,6 +914,7 @@
 	unblock_operations(sbi);
 	mutex_unlock(&sbi->cp_mutex);
 
+	stat_inc_cp_count(sbi->stat_info);
 	trace_f2fs_write_checkpoint(sbi->sb, is_umount, "finish checkpoint");
 }
 
diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index 3de9d20..46a12e4 100644
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -236,6 +236,7 @@
 			   si->dirty_count);
 		seq_printf(s, "  - Prefree: %d\n  - Free: %d (%d)\n\n",
 			   si->prefree_count, si->free_segs, si->free_secs);
+		seq_printf(s, "CP calls: %d\n", si->cp_count);
 		seq_printf(s, "GC calls: %d (BG: %d)\n",
 			   si->call_count, si->bg_gc);
 		seq_printf(s, "  - data segments : %d\n", si->data_segs);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 817eccc..91f4c5e 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1255,7 +1255,7 @@
 	int util_free, util_valid, util_invalid;
 	int rsvd_segs, overp_segs;
 	int dirty_count, node_pages, meta_pages;
-	int prefree_count, call_count;
+	int prefree_count, call_count, cp_count;
 	int tot_segs, node_segs, data_segs, free_segs, free_secs;
 	int tot_blks, data_blks, node_blks;
 	int curseg[NR_CURSEG_TYPE];
@@ -1272,6 +1272,7 @@
 	return (struct f2fs_stat_info *)sbi->stat_info;
 }
 
+#define stat_inc_cp_count(si)		((si)->cp_count++)
 #define stat_inc_call_count(si)		((si)->call_count++)
 #define stat_inc_bggc_count(sbi)	((sbi)->bg_gc++)
 #define stat_inc_dirty_dir(sbi)		((sbi)->n_dirty_dirs++)
@@ -1326,6 +1327,7 @@
 void __init f2fs_create_root_stats(void);
 void f2fs_destroy_root_stats(void);
 #else
+#define stat_inc_cp_count(si)
 #define stat_inc_call_count(si)
 #define stat_inc_bggc_count(si)
 #define stat_inc_dirty_dir(sbi)