f2fs: add f2fs_io_tracer support

This patch adds:
 o initial trace.c and trace.h with skeleton functions
 o Kconfig and Makefile to activate this feature

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/fs/f2fs/Kconfig b/fs/f2fs/Kconfig
index 736a348509f7..94e2d2ffabe1 100644
--- a/fs/f2fs/Kconfig
+++ b/fs/f2fs/Kconfig
@@ -71,3 +71,13 @@ config F2FS_CHECK_FS
           Enables BUG_ONs which check the filesystem consistency in runtime.
 
           If you want to improve the performance, say N.
+
+config F2FS_IO_TRACE
+        bool "F2FS IO tracer"
+        depends on F2FS_FS
+        depends on FUNCTION_TRACER
+        help
+          F2FS IO trace is based on a function trace, which gathers process
+          information and block IO patterns in the filesystem level.
+
+          If unsure, say N.