Enforce that internal storage is prepared first

Before doing anything else in fscrypt_prepare_user_storage(), error out
if adoptable storage is being prepared before internal storage.  Without
this explicit check, making this mistake results in a sequence of weird
errors that is hard to trace back to the actual problem.

Bug: 231387956
Change-Id: Ib26cc1bd46ffa2578f6f0156dfacc5496dae3178
(cherry picked from commit c66c2e306dd9c253f5d25c377e6133909d44b86d)
Merged-In: Ib26cc1bd46ffa2578f6f0156dfacc5496dae3178

1 files changed, 17 insertions, 0 deletions

diff --git a/FsCrypt.cpp b/FsCrypt.cpp
index 42df78b1..6c081778 100644
--- a/FsCrypt.cpp
+++ b/FsCrypt.cpp
@@ -812,6 +812,23 @@ bool fscrypt_prepare_user_storage(const std::string& volume_uuid, userid_t user_
     LOG(DEBUG) << "fscrypt_prepare_user_storage for volume " << escape_empty(volume_uuid)
                << ", user " << user_id << ", serial " << serial << ", flags " << flags;
 
+    // Internal storage must be prepared before adoptable storage, since the
+    // user's volume keys are stored in their internal storage.
+    if (!volume_uuid.empty()) {
+        if ((flags & android::os::IVold::STORAGE_FLAG_DE) &&
+            !android::vold::pathExists(android::vold::BuildDataMiscDePath("", user_id))) {
+            LOG(ERROR) << "Cannot prepare DE storage for user " << user_id << " on volume "
+                       << volume_uuid << " before internal storage";
+            return false;
+        }
+        if ((flags & android::os::IVold::STORAGE_FLAG_CE) &&
+            !android::vold::pathExists(android::vold::BuildDataMiscCePath("", user_id))) {
+            LOG(ERROR) << "Cannot prepare CE storage for user " << user_id << " on volume "
+                       << volume_uuid << " before internal storage";
+            return false;
+        }
+    }
+
     if (flags & android::os::IVold::STORAGE_FLAG_DE) {
         // DE_sys key
         auto system_legacy_path = android::vold::BuildDataSystemLegacyPath(user_id);