make tar backups opt in.

Change-Id: Ib01131f3a65ce4114e73abe2c7ba42263d281844

extendedcommands.c

@@ -1105,9 +1105,9 @@ int bml_check_volume(const char *path) {
 
 void process_volumes() {
     create_fstab();
-    if (volume_for_path("/sdcard") == NULL) {
-        rmdir("/sdcard");
-        symlink("/data/media", "/sdcard");
+
+    if (is_data_media()) {
+        setup_data_media();
     }
 
     return;

nandroid.c

@@ -139,6 +139,17 @@ static nandroid_backup_handler get_backup_handler(const char *backup_path) {
         return NULL;
     }
 
+    if (strcmp(backup_path, "/data") == 0 && is_data_media()) {
+        return tar_compress_wrapper;
+    }
+
+    char str[255];
+    char* partition;
+    property_get("ro.cwm.prefer_tar", str, "false");
+    if (strcmp("true", str) != 0) {
+        return mkyaffs2image_wrapper;
+    }
+
     if (strcmp("yaffs2", mv->filesystem) == 0) {
         return mkyaffs2image_wrapper;
     }
@@ -345,6 +356,17 @@ static nandroid_restore_handler get_restore_handler(const char *backup_path) {
         return NULL;
     }
 
+    if (strcmp(backup_path, "/data") == 0 && is_data_media()) {
+        return tar_extract_wrapper;
+    }
+
+    char str[255];
+    char* partition;
+    property_get("ro.cwm.prefer_tar", str, "false");
+    if (strcmp("true", str) != 0) {
+        return unyaffs_wrapper;
+    }
+
     if (strcmp("yaffs2", mv->filesystem) == 0) {
         return unyaffs_wrapper;
     }

roots.c

@@ -164,17 +164,27 @@ int try_mount(const char* device, const char* mount_point, const char* fs_type,
     return ret;
 }
 
+int is_data_media() {
+    Volume *data = volume_for_path("/data");
+    return data != NULL && strcmp(data->fs_type, "auto") == 0 && volume_for_path("/sdcard") == NULL;
+}
+
+void setup_data_media() {
+    rmdir("/sdcard");
+    mkdir("/data/media", 0755);
+    symlink("/data/media", "/sdcard");
+}
+
 int ensure_path_mounted(const char* path) {
     Volume* v = volume_for_path(path);
     if (v == NULL) {
         // no /sdcard? let's assume /data/media
-        if (strstr(path, "/sdcard") == path) {
+        if (strstr(path, "/sdcard") == path && is_data_media()) {
             LOGW("using /data/media, no /sdcard found.\n");
             int ret;
             if (0 != (ret = ensure_path_mounted("/data")))
                 return ret;
-            rmdir("/sdcard");
-            symlink("/data/media", "/sdcard");
+            setup_data_media();
             return 0;
         }
         LOGE("unknown volume for path [%s]\n", path);
@@ -245,7 +255,7 @@ int ensure_path_unmounted(const char* path) {
     Volume* v = volume_for_path(path);
     if (v == NULL) {
         // no /sdcard? let's assume /data/media
-        if (strstr(path, "/sdcard") == path) {
+        if (strstr(path, "/sdcard") == path && is_data_media()) {
             return ensure_path_unmounted("/data");
         }
         LOGE("unknown volume for path [%s]\n", path);

roots.h

@@ -42,4 +42,7 @@ int get_num_volumes();
 
 Volume* get_device_volumes();
 
+int is_data_media();
+void setup_data_media();
+
 #endif  // RECOVERY_ROOTS_H_