[HACK]fs_mgr+init: Format via recovery if encryptable /data is wiped

If the encryptable partition is wiped (4KB worth of 0 or 0xff),
then reboot into recovery to format /data+/cache

This is while waiting for the Mac OS support to format f2fs.
The flashstation running on Mac OS will currently just erase userdata
and not format it with f2fs.

Bug: 15720406
Bug: 15747366
Change-Id: Ib7cca3e1701483a09573457a835750f34da71ee0

1 files changed, 27 insertions, 0 deletions

diff --git a/init/builtins.c b/init/builtins.c
index dd147f6..f7bd8a9 100644
--- a/init/builtins.c
+++ b/init/builtins.c
@@ -474,6 +474,26 @@ exit_success:
 
 }
 
+static int wipe_data_via_recovery()
+{
+    mkdir("/cache/recovery", 0700);
+    int fd = open("/cache/recovery/command", O_RDWR|O_CREAT|O_TRUNC, 0600);
+    if (fd >= 0) {
+        write(fd, "--wipe_data", strlen("--wipe_data") + 1);
+        close(fd);
+    } else {
+        ERROR("could not open /cache/recovery/command\n");
+        return -1;
+    }
+    android_reboot(ANDROID_RB_RESTART2, 0, "recovery");
+    while (1) { pause(); }  // never reached
+}
+
+
+/*
+ * This function might request a reboot, in which case it will
+ * not return.
+ */
 int do_mount_all(int nargs, char **args)
 {
     pid_t pid;
@@ -529,6 +549,13 @@ int do_mount_all(int nargs, char **args)
          * that action.
          */
         action_for_each_trigger("nonencrypted", action_add_queue_tail);
+    } else if (ret == FS_MGR_MNTALL_DEV_NEEDS_RECOVERY) {
+        /* Setup a wipe via recovery, and reboot into recovery */
+        ERROR("fs_mgr_mount_all suggested recovery, so wiping data via recovery.\n");
+        ret = wipe_data_via_recovery();
+        /* If reboot worked, there is no return. */
+    } else if (ret > 0) {
+        ERROR("fs_mgr_mount_all returned unexpected error %d\n", ret);
     }
     /* else ... < 0: error */