e2fsck: drop -f when TARGET_USES_MKE2FS is enabled

- Drop forced (-f) e2fsck check when the product has
  enabled new ext4 generation by setting TARGET_USES_MKE2FS.
- The new generation tool is supposed to give better stability,
  thus justifying dropping -f.
- This should help reducing boot-up time as full check (-f) can
  increase boot-up time significantly depending on amount of data.

bug: 32246772
Test: many reboots
Change-Id: I631525bf7504bbfb025e170c8d24ad9d3ef3532e

fs_mgr/Android.mk

@@ -32,6 +32,11 @@ LOCAL_MODULE:= libfs_mgr
 LOCAL_STATIC_LIBRARIES := $(common_static_libraries)
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
 LOCAL_CFLAGS := -Werror
+ifeq ($(TARGET_USERIMAGES_USE_EXT4), true)
+  ifeq ($(TARGET_USES_MKE2FS), true)
+    LOCAL_CFLAGS += -DTARGET_USES_MKE2FS
+  endif
+endif
 ifneq (,$(filter userdebug,$(TARGET_BUILD_VARIANT)))
 LOCAL_CFLAGS += -DALLOW_ADBD_DISABLE_VERITY=1
 endif

fs_mgr/fs_mgr.c

@@ -101,7 +101,9 @@ static void check_fs(char *blk_device, char *fs_type, char *target)
     char tmpmnt_opts[64] = "errors=remount-ro";
     char *e2fsck_argv[] = {
         E2FSCK_BIN,
+#ifndef TARGET_USES_MKE2FS // "-f" only for old ext4 generation tool
         "-f",
+#endif
         "-y",
         blk_device
     };