f2fs: add tracepoints for GC threads

Add tracepoints for tracing the garbage collector
threads in f2fs with status of collection & type.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
[Jaegeuk: modify slightly to show information]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 37b05e1..1ca3324 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -23,6 +23,7 @@
 #include "node.h"
 #include "segment.h"
 #include "gc.h"
+#include <trace/events/f2fs.h>
 
 static struct kmem_cache *winode_slab;
 
@@ -301,6 +302,10 @@
 				set_bit(secno, dirty_i->victim_secmap);
 		}
 		*result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
+
+		trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
+				sbi->cur_victim_sec,
+				prefree_segments(sbi), free_segments(sbi));
 	}
 	mutex_unlock(&dirty_i->seglist_lock);