diff --git a/Android.bp b/Android.bp
index 55def04..b621f35 100644
--- a/Android.bp
+++ b/Android.bp
@@ -86,6 +86,7 @@
 
 cc_library_headers {
     name: "libvold_headers",
+    recovery_available: true,
     export_include_dirs: ["."],
 }
 
diff --git a/Checkpoint.cpp b/Checkpoint.cpp
index e5ef4a2..b2b648f 100644
--- a/Checkpoint.cpp
+++ b/Checkpoint.cpp
@@ -145,8 +145,10 @@
 
 volatile bool isCheckpointing = false;
 
-// Protects isCheckpointing and code that makes decisions based on status of
-// isCheckpointing
+volatile bool needsCheckpointWasCalled = false;
+
+// Protects isCheckpointing, needsCheckpointWasCalled and code that makes decisions based on status
+// of isCheckpointing
 std::mutex isCheckpointingLock;
 }
 
@@ -263,16 +265,16 @@
 }
 
 bool cp_needsCheckpoint() {
+    std::lock_guard<std::mutex> lock(isCheckpointingLock);
+
     // Make sure we only return true during boot. See b/138952436 for discussion
-    static bool called_once = false;
-    if (called_once) return isCheckpointing;
-    called_once = true;
+    if (needsCheckpointWasCalled) return isCheckpointing;
+    needsCheckpointWasCalled = true;
 
     bool ret;
     std::string content;
     sp<IBootControl> module = IBootControl::getService();
 
-    std::lock_guard<std::mutex> lock(isCheckpointingLock);
     if (isCheckpointing) return isCheckpointing;
 
     if (module && module->isSlotMarkedSuccessful(module->getCurrentSlot()) == BoolResult::FALSE) {
@@ -342,6 +344,8 @@
 }  // namespace
 
 Status cp_prepareCheckpoint() {
+    // Log to notify CTS - see b/137924328 for context
+    LOG(INFO) << "cp_prepareCheckpoint called";
     std::lock_guard<std::mutex> lock(isCheckpointingLock);
     if (!isCheckpointing) {
         return Status::ok();
@@ -727,5 +731,10 @@
     return Status::ok();
 }
 
+void cp_resetCheckpoint() {
+    std::lock_guard<std::mutex> lock(isCheckpointingLock);
+    needsCheckpointWasCalled = false;
+}
+
 }  // namespace vold
 }  // namespace android
diff --git a/Checkpoint.h b/Checkpoint.h
index 63ead83..c1fb2b7 100644
--- a/Checkpoint.h
+++ b/Checkpoint.h
@@ -45,6 +45,7 @@
 
 android::binder::Status cp_markBootAttempt();
 
+void cp_resetCheckpoint();
 }  // namespace vold
 }  // namespace android
 
diff --git a/FsCrypt.cpp b/FsCrypt.cpp
index 8d78473..c101ba8 100644
--- a/FsCrypt.cpp
+++ b/FsCrypt.cpp
@@ -57,6 +57,7 @@
 #include <android-base/logging.h>
 #include <android-base/properties.h>
 #include <android-base/stringprintf.h>
+#include <android-base/strings.h>
 #include <android-base/unique_fd.h>
 
 using android::base::StringPrintf;
@@ -64,15 +65,10 @@
 using android::vold::kEmptyAuthentication;
 using android::vold::KeyBuffer;
 using android::vold::writeStringToFile;
+using namespace android::fscrypt;
 
 namespace {
 
-struct PolicyKeyRef {
-    std::string contents_mode;
-    std::string filenames_mode;
-    std::string key_raw_ref;
-};
-
 const std::string device_key_dir = std::string() + DATA_MNT_POINT + fscrypt_unencrypted_folder;
 const std::string device_key_path = device_key_dir + "/key";
 const std::string device_key_temp = device_key_dir + "/temp";
@@ -199,13 +195,54 @@
     return false;
 }
 
+// Retrieve the options to use for encryption policies on the /data filesystem.
+static void get_data_file_encryption_options(EncryptionOptions* options) {
+    auto entry = GetEntryForMountPoint(&fstab_default, DATA_MNT_POINT);
+    if (entry == nullptr) {
+        return;
+    }
+    if (!ParseOptions(entry->encryption_options, options)) {
+        LOG(ERROR) << "Unable to parse encryption options for " << DATA_MNT_POINT ": "
+                   << entry->encryption_options;
+        return;
+    }
+}
+
+// Retrieve the version to use for encryption policies on the /data filesystem.
+static int get_data_file_policy_version(void) {
+    EncryptionOptions options;
+    get_data_file_encryption_options(&options);
+    return options.version;
+}
+
+// Retrieve the options to use for encryption policies on adoptable storage.
+static bool get_volume_file_encryption_options(EncryptionOptions* options) {
+    auto contents_mode =
+            android::base::GetProperty("ro.crypto.volume.contents_mode", "aes-256-xts");
+    auto filenames_mode =
+            android::base::GetProperty("ro.crypto.volume.filenames_mode", "aes-256-heh");
+    return ParseOptions(android::base::GetProperty("ro.crypto.volume.options",
+                                                   contents_mode + ":" + filenames_mode + ":v1"),
+                        options);
+}
+
+// Install a key for use by encrypted files on the /data filesystem.
+static bool install_data_key(const KeyBuffer& key, std::string* raw_ref) {
+    return android::vold::installKey(key, DATA_MNT_POINT, get_data_file_policy_version(), raw_ref);
+}
+
+// Evict a key for use by encrypted files on the /data filesystem.
+static bool evict_data_key(const std::string& raw_ref) {
+    return android::vold::evictKey(DATA_MNT_POINT, raw_ref, get_data_file_policy_version());
+}
+
 static bool read_and_install_user_ce_key(userid_t user_id,
                                          const android::vold::KeyAuthentication& auth) {
     if (s_ce_key_raw_refs.count(user_id) != 0) return true;
     KeyBuffer ce_key;
     if (!read_and_fixate_user_ce_key(user_id, auth, &ce_key)) return false;
     std::string ce_raw_ref;
-    if (!android::vold::installKey(ce_key, &ce_raw_ref)) return false;
+    if (!install_data_key(ce_key, &ce_raw_ref)) return false;
     s_ce_keys[user_id] = std::move(ce_key);
     s_ce_key_raw_refs[user_id] = ce_raw_ref;
     LOG(DEBUG) << "Installed ce key for user " << user_id;
@@ -255,10 +292,10 @@
             return false;
     }
     std::string de_raw_ref;
-    if (!android::vold::installKey(de_key, &de_raw_ref)) return false;
+    if (!install_data_key(de_key, &de_raw_ref)) return false;
     s_de_key_raw_refs[user_id] = de_raw_ref;
     std::string ce_raw_ref;
-    if (!android::vold::installKey(ce_key, &ce_raw_ref)) return false;
+    if (!install_data_key(ce_key, &ce_raw_ref)) return false;
     s_ce_keys[user_id] = ce_key;
     s_ce_key_raw_refs[user_id] = ce_raw_ref;
     LOG(DEBUG) << "Created keys for user " << user_id;
@@ -276,21 +313,6 @@
     return true;
 }
 
-static void get_data_file_encryption_modes(PolicyKeyRef* key_ref) {
-    auto entry = GetEntryForMountPoint(&fstab_default, DATA_MNT_POINT);
-    if (entry == nullptr) {
-        return;
-    }
-    key_ref->contents_mode = entry->file_contents_mode;
-    key_ref->filenames_mode = entry->file_names_mode;
-}
-
-static bool ensure_policy(const PolicyKeyRef& key_ref, const std::string& path) {
-    return fscrypt_policy_ensure(path.c_str(), key_ref.key_raw_ref.data(),
-                                 key_ref.key_raw_ref.size(), key_ref.contents_mode.c_str(),
-                                 key_ref.filenames_mode.c_str()) == 0;
-}
-
 static bool is_numeric(const char* name) {
     for (const char* p = name; *p != '\0'; p++) {
         if (!isdigit(*p)) return false;
@@ -325,7 +347,7 @@
             KeyBuffer key;
             if (!android::vold::retrieveKey(key_path, kEmptyAuthentication, &key)) return false;
             std::string raw_ref;
-            if (!android::vold::installKey(key, &raw_ref)) return false;
+            if (!install_data_key(key, &raw_ref)) return false;
             s_de_key_raw_refs[user_id] = raw_ref;
             LOG(DEBUG) << "Installed de key for user " << user_id;
         }
@@ -343,24 +365,30 @@
         return true;
     }
 
-    PolicyKeyRef device_ref;
-    if (!android::vold::retrieveAndInstallKey(true, kEmptyAuthentication, device_key_path,
-                                              device_key_temp, &device_ref.key_raw_ref))
-        return false;
-    get_data_file_encryption_modes(&device_ref);
+    EncryptionPolicy device_policy;
+    get_data_file_encryption_options(&device_policy.options);
 
-    std::string modestring = device_ref.contents_mode + ":" + device_ref.filenames_mode;
-    std::string mode_filename = std::string("/data") + fscrypt_key_mode;
-    if (!android::vold::writeStringToFile(modestring, mode_filename)) return false;
+    if (!android::vold::retrieveAndInstallKey(true, kEmptyAuthentication, device_key_path,
+                                              device_key_temp, "", device_policy.options.version,
+                                              &device_policy.key_raw_ref))
+        return false;
+
+    std::string options_string;
+    if (!OptionsToString(device_policy.options, &options_string)) {
+        LOG(ERROR) << "Unable to serialize options";
+        return false;
+    }
+    std::string options_filename = std::string("/data") + fscrypt_key_mode;
+    if (!android::vold::writeStringToFile(options_string, options_filename)) return false;
 
     std::string ref_filename = std::string("/data") + fscrypt_key_ref;
-    if (!android::vold::writeStringToFile(device_ref.key_raw_ref, ref_filename)) return false;
+    if (!android::vold::writeStringToFile(device_policy.key_raw_ref, ref_filename)) return false;
     LOG(INFO) << "Wrote system DE key reference to:" << ref_filename;
 
     KeyBuffer per_boot_key;
     if (!android::vold::randomKey(&per_boot_key)) return false;
     std::string per_boot_raw_ref;
-    if (!android::vold::installKey(per_boot_key, &per_boot_raw_ref)) return false;
+    if (!install_data_key(per_boot_key, &per_boot_raw_ref)) return false;
     std::string per_boot_ref_filename = std::string("/data") + fscrypt_key_per_boot_ref;
     if (!android::vold::writeStringToFile(per_boot_raw_ref, per_boot_ref_filename)) return false;
     LOG(INFO) << "Wrote per boot key reference to:" << per_boot_ref_filename;
@@ -419,15 +447,20 @@
 }
 
 // "Lock" all encrypted directories whose key has been removed.  This is needed
-// because merely removing the keyring key doesn't affect inodes in the kernel's
-// inode cache whose per-file key was already set up.  So to remove the per-file
-// keys and make the files "appear encrypted", these inodes must be evicted.
+// in the case where the keys are being put in the session keyring (rather in
+// the newer filesystem-level keyrings), because removing a key from the session
+// keyring doesn't affect inodes in the kernel's inode cache whose per-file key
+// was already set up.  So to remove the per-file keys and make the files
+// "appear encrypted", these inodes must be evicted.
 //
 // To do this, sync() to clean all dirty inodes, then drop all reclaimable slab
 // objects systemwide.  This is overkill, but it's the best available method
 // currently.  Don't use drop_caches mode "3" because that also evicts pagecache
 // for in-use files; all files relevant here are already closed and sync'ed.
-static void drop_caches() {
+static void drop_caches_if_needed() {
+    if (android::vold::isFsKeyringSupported()) {
+        return;
+    }
     sync();
     if (!writeStringToFile("2", "/proc/sys/vm/drop_caches")) {
         PLOG(ERROR) << "Failed to drop caches during key eviction";
@@ -440,8 +473,8 @@
     std::string raw_ref;
     // If we haven't loaded the CE key, no need to evict it.
     if (lookup_key_ref(s_ce_key_raw_refs, user_id, &raw_ref)) {
-        success &= android::vold::evictKey(raw_ref);
-        drop_caches();
+        success &= evict_data_key(raw_ref);
+        drop_caches_if_needed();
     }
     s_ce_key_raw_refs.erase(user_id);
     return success;
@@ -455,8 +488,7 @@
     bool success = true;
     std::string raw_ref;
     success &= evict_ce_key(user_id);
-    success &=
-        lookup_key_ref(s_de_key_raw_refs, user_id, &raw_ref) && android::vold::evictKey(raw_ref);
+    success &= lookup_key_ref(s_de_key_raw_refs, user_id, &raw_ref) && evict_data_key(raw_ref);
     s_de_key_raw_refs.erase(user_id);
     auto it = s_ephemeral_users.find(user_id);
     if (it != s_ephemeral_users.end()) {
@@ -526,7 +558,7 @@
 }
 
 static bool read_or_create_volkey(const std::string& misc_path, const std::string& volume_uuid,
-                                  PolicyKeyRef* key_ref) {
+                                  EncryptionPolicy* policy) {
     auto secdiscardable_path = volume_secdiscardable_path(volume_uuid);
     std::string secdiscardable_hash;
     if (android::vold::pathExists(secdiscardable_path)) {
@@ -546,14 +578,12 @@
         return false;
     }
     android::vold::KeyAuthentication auth("", secdiscardable_hash);
-    if (!android::vold::retrieveAndInstallKey(true, auth, key_path, key_path + "_tmp",
-                                              &key_ref->key_raw_ref))
-        return false;
-    key_ref->contents_mode =
-        android::base::GetProperty("ro.crypto.volume.contents_mode", "aes-256-xts");
-    key_ref->filenames_mode =
-        android::base::GetProperty("ro.crypto.volume.filenames_mode", "aes-256-heh");
-    return true;
+
+    if (!get_volume_file_encryption_options(&policy->options)) return false;
+
+    return android::vold::retrieveAndInstallKey(true, auth, key_path, key_path + "_tmp",
+                                                volume_uuid, policy->options.version,
+                                                &policy->key_raw_ref);
 }
 
 static bool destroy_volkey(const std::string& misc_path, const std::string& volume_uuid) {
@@ -698,17 +728,18 @@
         if (!prepare_dir(user_de_path, 0771, AID_SYSTEM, AID_SYSTEM)) return false;
 
         if (fscrypt_is_native()) {
-            PolicyKeyRef de_ref;
+            EncryptionPolicy de_policy;
             if (volume_uuid.empty()) {
-                if (!lookup_key_ref(s_de_key_raw_refs, user_id, &de_ref.key_raw_ref)) return false;
-                get_data_file_encryption_modes(&de_ref);
-                if (!ensure_policy(de_ref, system_de_path)) return false;
-                if (!ensure_policy(de_ref, misc_de_path)) return false;
-                if (!ensure_policy(de_ref, vendor_de_path)) return false;
+                if (!lookup_key_ref(s_de_key_raw_refs, user_id, &de_policy.key_raw_ref))
+                    return false;
+                get_data_file_encryption_options(&de_policy.options);
+                if (!EnsurePolicy(de_policy, system_de_path)) return false;
+                if (!EnsurePolicy(de_policy, misc_de_path)) return false;
+                if (!EnsurePolicy(de_policy, vendor_de_path)) return false;
             } else {
-                if (!read_or_create_volkey(misc_de_path, volume_uuid, &de_ref)) return false;
+                if (!read_or_create_volkey(misc_de_path, volume_uuid, &de_policy)) return false;
             }
-            if (!ensure_policy(de_ref, user_de_path)) return false;
+            if (!EnsurePolicy(de_policy, user_de_path)) return false;
         }
     }
 
@@ -729,19 +760,20 @@
         if (!prepare_dir(user_ce_path, 0771, AID_SYSTEM, AID_SYSTEM)) return false;
 
         if (fscrypt_is_native()) {
-            PolicyKeyRef ce_ref;
+            EncryptionPolicy ce_policy;
             if (volume_uuid.empty()) {
-                if (!lookup_key_ref(s_ce_key_raw_refs, user_id, &ce_ref.key_raw_ref)) return false;
-                get_data_file_encryption_modes(&ce_ref);
-                if (!ensure_policy(ce_ref, system_ce_path)) return false;
-                if (!ensure_policy(ce_ref, misc_ce_path)) return false;
-                if (!ensure_policy(ce_ref, vendor_ce_path)) return false;
+                if (!lookup_key_ref(s_ce_key_raw_refs, user_id, &ce_policy.key_raw_ref))
+                    return false;
+                get_data_file_encryption_options(&ce_policy.options);
+                if (!EnsurePolicy(ce_policy, system_ce_path)) return false;
+                if (!EnsurePolicy(ce_policy, misc_ce_path)) return false;
+                if (!EnsurePolicy(ce_policy, vendor_ce_path)) return false;
 
             } else {
-                if (!read_or_create_volkey(misc_ce_path, volume_uuid, &ce_ref)) return false;
+                if (!read_or_create_volkey(misc_ce_path, volume_uuid, &ce_policy)) return false;
             }
-            if (!ensure_policy(ce_ref, media_ce_path)) return false;
-            if (!ensure_policy(ce_ref, user_ce_path)) return false;
+            if (!EnsurePolicy(ce_policy, media_ce_path)) return false;
+            if (!EnsurePolicy(ce_policy, user_ce_path)) return false;
         }
 
         if (volume_uuid.empty()) {
diff --git a/KeyUtil.cpp b/KeyUtil.cpp
index 12cae9b..f822377 100644
--- a/KeyUtil.cpp
+++ b/KeyUtil.cpp
@@ -16,12 +16,14 @@
 
 #include "KeyUtil.h"
 
-#include <linux/fs.h>
 #include <iomanip>
 #include <sstream>
 #include <string>
 
+#include <fcntl.h>
+#include <linux/fs.h>
 #include <openssl/sha.h>
+#include <sys/ioctl.h>
 
 #include <android-base/file.h>
 #include <android-base/logging.h>
@@ -29,6 +31,7 @@
 
 #include "KeyStorage.h"
 #include "Utils.h"
+#include "fscrypt_uapi.h"
 
 namespace android {
 namespace vold {
@@ -45,6 +48,42 @@
     return true;
 }
 
+// Return true if the kernel supports the ioctls to add/remove fscrypt keys
+// directly to/from the filesystem.
+bool isFsKeyringSupported(void) {
+    static bool initialized = false;
+    static bool supported;
+
+    if (!initialized) {
+        android::base::unique_fd fd(open("/data", O_RDONLY | O_DIRECTORY | O_CLOEXEC));
+
+        // FS_IOC_ADD_ENCRYPTION_KEY with a NULL argument will fail with ENOTTY
+        // if the ioctl isn't supported.  Otherwise it will fail with another
+        // error code such as EFAULT.
+        errno = 0;
+        (void)ioctl(fd, FS_IOC_ADD_ENCRYPTION_KEY, NULL);
+        if (errno == ENOTTY) {
+            LOG(INFO) << "Kernel doesn't support FS_IOC_ADD_ENCRYPTION_KEY.  Falling back to "
+                         "session keyring";
+            supported = false;
+        } else {
+            if (errno != EFAULT) {
+                PLOG(WARNING) << "Unexpected error from FS_IOC_ADD_ENCRYPTION_KEY";
+            }
+            LOG(DEBUG) << "Detected support for FS_IOC_ADD_ENCRYPTION_KEY";
+            supported = true;
+        }
+        // There's no need to check for FS_IOC_REMOVE_ENCRYPTION_KEY, since it's
+        // guaranteed to be available if FS_IOC_ADD_ENCRYPTION_KEY is.  There's
+        // also no need to check for support on external volumes separately from
+        // /data, since either the kernel supports the ioctls on all
+        // fscrypt-capable filesystems or it doesn't.
+
+        initialized = true;
+    }
+    return supported;
+}
+
 // Get raw keyref - used to make keyname and to pass to ioctl
 static std::string generateKeyRef(const uint8_t* key, int length) {
     SHA512_CTX c;
@@ -78,16 +117,20 @@
 
 static char const* const NAME_PREFIXES[] = {"ext4", "f2fs", "fscrypt", nullptr};
 
-static std::string keyname(const std::string& prefix, const std::string& raw_ref) {
+static std::string keyrefstring(const std::string& raw_ref) {
     std::ostringstream o;
-    o << prefix << ":";
     for (unsigned char i : raw_ref) {
         o << std::hex << std::setw(2) << std::setfill('0') << (int)i;
     }
     return o.str();
 }
 
-// Get the keyring we store all keys in
+static std::string buildLegacyKeyName(const std::string& prefix, const std::string& raw_ref) {
+    return prefix + ":" + keyrefstring(raw_ref);
+}
+
+// Get the ID of the keyring we store all fscrypt keys in when the kernel is too
+// old to support FS_IOC_ADD_ENCRYPTION_KEY and FS_IOC_REMOVE_ENCRYPTION_KEY.
 static bool fscryptKeyring(key_serial_t* device_keyring) {
     *device_keyring = keyctl_search(KEY_SPEC_SESSION_KEYRING, "keyring", "fscrypt", 0);
     if (*device_keyring == -1) {
@@ -97,19 +140,17 @@
     return true;
 }
 
-// Install password into global keyring
-// Return raw key reference for use in policy
-bool installKey(const KeyBuffer& key, std::string* raw_ref) {
+// Add an encryption key to the legacy global session keyring.
+static bool installKeyLegacy(const KeyBuffer& key, const std::string& raw_ref) {
     // Place fscrypt_key into automatically zeroing buffer.
     KeyBuffer fsKeyBuffer(sizeof(fscrypt_key));
     fscrypt_key& fs_key = *reinterpret_cast<fscrypt_key*>(fsKeyBuffer.data());
 
     if (!fillKey(key, &fs_key)) return false;
-    *raw_ref = generateKeyRef(fs_key.raw, fs_key.size);
     key_serial_t device_keyring;
     if (!fscryptKeyring(&device_keyring)) return false;
     for (char const* const* name_prefix = NAME_PREFIXES; *name_prefix != nullptr; name_prefix++) {
-        auto ref = keyname(*name_prefix, *raw_ref);
+        auto ref = buildLegacyKeyName(*name_prefix, raw_ref);
         key_serial_t key_id =
             add_key("logon", ref.c_str(), (void*)&fs_key, sizeof(fs_key), device_keyring);
         if (key_id == -1) {
@@ -122,12 +163,110 @@
     return true;
 }
 
-bool evictKey(const std::string& raw_ref) {
+// Build a struct fscrypt_key_specifier for use in the key management ioctls.
+static bool buildKeySpecifier(fscrypt_key_specifier* spec, const std::string& raw_ref,
+                              int policy_version) {
+    switch (policy_version) {
+        case 1:
+            if (raw_ref.size() != FSCRYPT_KEY_DESCRIPTOR_SIZE) {
+                LOG(ERROR) << "Invalid key specifier size for v1 encryption policy: "
+                           << raw_ref.size();
+                return false;
+            }
+            spec->type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR;
+            memcpy(spec->u.descriptor, raw_ref.c_str(), FSCRYPT_KEY_DESCRIPTOR_SIZE);
+            return true;
+        case 2:
+            if (raw_ref.size() != FSCRYPT_KEY_IDENTIFIER_SIZE) {
+                LOG(ERROR) << "Invalid key specifier size for v2 encryption policy: "
+                           << raw_ref.size();
+                return false;
+            }
+            spec->type = FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER;
+            memcpy(spec->u.identifier, raw_ref.c_str(), FSCRYPT_KEY_IDENTIFIER_SIZE);
+            return true;
+        default:
+            LOG(ERROR) << "Invalid encryption policy version: " << policy_version;
+            return false;
+    }
+}
+
+// Install a file-based encryption key to the kernel, for use by encrypted files
+// on the specified filesystem using the specified encryption policy version.
+//
+// For v1 policies, we use FS_IOC_ADD_ENCRYPTION_KEY if the kernel supports it.
+// Otherwise we add the key to the legacy global session keyring.
+//
+// For v2 policies, we always use FS_IOC_ADD_ENCRYPTION_KEY; it's the only way
+// the kernel supports.
+//
+// Returns %true on success, %false on failure.  On success also sets *raw_ref
+// to the raw key reference for use in the encryption policy.
+bool installKey(const KeyBuffer& key, const std::string& mountpoint, int policy_version,
+                std::string* raw_ref) {
+    // Put the fscrypt_add_key_arg in an automatically-zeroing buffer, since we
+    // have to copy the raw key into it.
+    KeyBuffer arg_buf(sizeof(struct fscrypt_add_key_arg) + key.size(), 0);
+    struct fscrypt_add_key_arg* arg = (struct fscrypt_add_key_arg*)arg_buf.data();
+
+    // Initialize the "key specifier", which is like a name for the key.
+    switch (policy_version) {
+        case 1:
+            // A key for a v1 policy is specified by an arbitrary 8-byte
+            // "descriptor", which must be provided by userspace.  We use the
+            // first 8 bytes from the double SHA-512 of the key itself.
+            *raw_ref = generateKeyRef((const uint8_t*)key.data(), key.size());
+            if (!isFsKeyringSupported()) {
+                return installKeyLegacy(key, *raw_ref);
+            }
+            if (!buildKeySpecifier(&arg->key_spec, *raw_ref, policy_version)) {
+                return false;
+            }
+            break;
+        case 2:
+            // A key for a v2 policy is specified by an 16-byte "identifier",
+            // which is a cryptographic hash of the key itself which the kernel
+            // computes and returns.  Any user-provided value is ignored; we
+            // just need to set the specifier type to indicate that we're adding
+            // this type of key.
+            arg->key_spec.type = FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER;
+            break;
+        default:
+            LOG(ERROR) << "Invalid encryption policy version: " << policy_version;
+            return false;
+    }
+
+    // Provide the raw key.
+    arg->raw_size = key.size();
+    memcpy(arg->raw, key.data(), key.size());
+
+    android::base::unique_fd fd(open(mountpoint.c_str(), O_RDONLY | O_DIRECTORY | O_CLOEXEC));
+    if (fd == -1) {
+        PLOG(ERROR) << "Failed to open " << mountpoint << " to install key";
+        return false;
+    }
+
+    if (ioctl(fd, FS_IOC_ADD_ENCRYPTION_KEY, arg) != 0) {
+        PLOG(ERROR) << "Failed to install fscrypt key to " << mountpoint;
+        return false;
+    }
+
+    if (arg->key_spec.type == FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER) {
+        // Retrieve the key identifier that the kernel computed.
+        *raw_ref = std::string((char*)arg->key_spec.u.identifier, FSCRYPT_KEY_IDENTIFIER_SIZE);
+    }
+    LOG(DEBUG) << "Installed fscrypt key with ref " << keyrefstring(*raw_ref) << " to "
+               << mountpoint;
+    return true;
+}
+
+// Remove an encryption key from the legacy global session keyring.
+static bool evictKeyLegacy(const std::string& raw_ref) {
     key_serial_t device_keyring;
     if (!fscryptKeyring(&device_keyring)) return false;
     bool success = true;
     for (char const* const* name_prefix = NAME_PREFIXES; *name_prefix != nullptr; name_prefix++) {
-        auto ref = keyname(*name_prefix, raw_ref);
+        auto ref = buildLegacyKeyName(*name_prefix, raw_ref);
         auto key_serial = keyctl_search(device_keyring, "logon", ref.c_str(), 0);
 
         // Unlink the key from the keyring.  Prefer unlinking to revoking or
@@ -144,8 +283,51 @@
     return success;
 }
 
+// Evict a file-based encryption key from the kernel.
+//
+// We use FS_IOC_REMOVE_ENCRYPTION_KEY if the kernel supports it.  Otherwise we
+// remove the key from the legacy global session keyring.
+//
+// In the latter case, the caller is responsible for dropping caches.
+bool evictKey(const std::string& mountpoint, const std::string& raw_ref, int policy_version) {
+    if (policy_version == 1 && !isFsKeyringSupported()) {
+        return evictKeyLegacy(raw_ref);
+    }
+
+    android::base::unique_fd fd(open(mountpoint.c_str(), O_RDONLY | O_DIRECTORY | O_CLOEXEC));
+    if (fd == -1) {
+        PLOG(ERROR) << "Failed to open " << mountpoint << " to evict key";
+        return false;
+    }
+
+    struct fscrypt_remove_key_arg arg;
+    memset(&arg, 0, sizeof(arg));
+
+    if (!buildKeySpecifier(&arg.key_spec, raw_ref, policy_version)) {
+        return false;
+    }
+
+    std::string ref = keyrefstring(raw_ref);
+
+    if (ioctl(fd, FS_IOC_REMOVE_ENCRYPTION_KEY, &arg) != 0) {
+        PLOG(ERROR) << "Failed to evict fscrypt key with ref " << ref << " from " << mountpoint;
+        return false;
+    }
+
+    LOG(DEBUG) << "Evicted fscrypt key with ref " << ref << " from " << mountpoint;
+    if (arg.removal_status_flags & FSCRYPT_KEY_REMOVAL_STATUS_FLAG_OTHER_USERS) {
+        // Should never happen because keys are only added/removed as root.
+        LOG(ERROR) << "Unexpected case: key with ref " << ref << " is still added by other users!";
+    } else if (arg.removal_status_flags & FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY) {
+        LOG(ERROR) << "Files still open after removing key with ref " << ref
+                   << ".  These files were not locked!";
+    }
+    return true;
+}
+
 bool retrieveAndInstallKey(bool create_if_absent, const KeyAuthentication& key_authentication,
                            const std::string& key_path, const std::string& tmp_path,
+                           const std::string& volume_uuid, int policy_version,
                            std::string* key_ref) {
     KeyBuffer key;
     if (pathExists(key_path)) {
@@ -161,7 +343,7 @@
         if (!storeKeyAtomically(key_path, tmp_path, key_authentication, key)) return false;
     }
 
-    if (!installKey(key, key_ref)) {
+    if (!installKey(key, BuildDataPath(volume_uuid), policy_version, key_ref)) {
         LOG(ERROR) << "Failed to install key in " << key_path;
         return false;
     }
diff --git a/KeyUtil.h b/KeyUtil.h
index 7ee6725..f6799d9 100644
--- a/KeyUtil.h
+++ b/KeyUtil.h
@@ -27,10 +27,15 @@
 namespace vold {
 
 bool randomKey(KeyBuffer* key);
-bool installKey(const KeyBuffer& key, std::string* raw_ref);
-bool evictKey(const std::string& raw_ref);
+
+bool isFsKeyringSupported(void);
+
+bool installKey(const KeyBuffer& key, const std::string& mountpoint, int policy_version,
+                std::string* raw_ref);
+bool evictKey(const std::string& mountpoint, const std::string& raw_ref, int policy_version);
 bool retrieveAndInstallKey(bool create_if_absent, const KeyAuthentication& key_authentication,
                            const std::string& key_path, const std::string& tmp_path,
+                           const std::string& volume_uuid, int policy_version,
                            std::string* key_ref);
 bool retrieveKey(bool create_if_absent, const std::string& key_path, const std::string& tmp_path,
                  KeyBuffer* key, bool keepOld = true);
diff --git a/VoldNativeService.cpp b/VoldNativeService.cpp
index 7f7f289..f17f59f 100644
--- a/VoldNativeService.cpp
+++ b/VoldNativeService.cpp
@@ -92,7 +92,7 @@
     }
 }
 
-binder::Status checkUid(uid_t expectedUid) {
+binder::Status checkUidOrRoot(uid_t expectedUid) {
     uid_t uid = IPCThreadState::self()->getCallingUid();
     if (uid == expectedUid || uid == AID_ROOT) {
         return ok();
@@ -147,12 +147,12 @@
     return ok();
 }
 
-#define ENFORCE_UID(uid)                         \
-    {                                            \
-        binder::Status status = checkUid((uid)); \
-        if (!status.isOk()) {                    \
-            return status;                       \
-        }                                        \
+#define ENFORCE_SYSTEM_OR_ROOT                              \
+    {                                                       \
+        binder::Status status = checkUidOrRoot(AID_SYSTEM); \
+        if (!status.isOk()) {                               \
+            return status;                                  \
+        }                                                   \
     }
 
 #define CHECK_ARGUMENT_ID(id)                          \
@@ -217,7 +217,7 @@
 
 binder::Status VoldNativeService::setListener(
     const android::sp<android::os::IVoldListener>& listener) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     VolumeManager::Instance()->setListener(listener);
@@ -225,7 +225,7 @@
 }
 
 binder::Status VoldNativeService::monitor() {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
 
     // Simply acquire/release each lock for watchdog
     { ACQUIRE_LOCK; }
@@ -235,42 +235,42 @@
 }
 
 binder::Status VoldNativeService::reset() {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return translate(VolumeManager::Instance()->reset());
 }
 
 binder::Status VoldNativeService::shutdown() {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return translate(VolumeManager::Instance()->shutdown());
 }
 
 binder::Status VoldNativeService::onUserAdded(int32_t userId, int32_t userSerial) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return translate(VolumeManager::Instance()->onUserAdded(userId, userSerial));
 }
 
 binder::Status VoldNativeService::onUserRemoved(int32_t userId) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return translate(VolumeManager::Instance()->onUserRemoved(userId));
 }
 
 binder::Status VoldNativeService::onUserStarted(int32_t userId) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return translate(VolumeManager::Instance()->onUserStarted(userId));
 }
 
 binder::Status VoldNativeService::onUserStopped(int32_t userId) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return translate(VolumeManager::Instance()->onUserStopped(userId));
@@ -287,7 +287,7 @@
 }
 
 binder::Status VoldNativeService::onSecureKeyguardStateChanged(bool isShowing) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return translate(VolumeManager::Instance()->onSecureKeyguardStateChanged(isShowing));
@@ -295,7 +295,7 @@
 
 binder::Status VoldNativeService::partition(const std::string& diskId, int32_t partitionType,
                                             int32_t ratio) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     CHECK_ARGUMENT_ID(diskId);
     ACQUIRE_LOCK;
 
@@ -317,7 +317,7 @@
 
 binder::Status VoldNativeService::forgetPartition(const std::string& partGuid,
                                                   const std::string& fsUuid) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     CHECK_ARGUMENT_HEX(partGuid);
     CHECK_ARGUMENT_HEX(fsUuid);
     ACQUIRE_LOCK;
@@ -327,7 +327,7 @@
 
 binder::Status VoldNativeService::mount(const std::string& volId, int32_t mountFlags,
                                         int32_t mountUserId) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     CHECK_ARGUMENT_ID(volId);
     ACQUIRE_LOCK;
 
@@ -353,7 +353,7 @@
 }
 
 binder::Status VoldNativeService::unmount(const std::string& volId) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     CHECK_ARGUMENT_ID(volId);
     ACQUIRE_LOCK;
 
@@ -365,7 +365,7 @@
 }
 
 binder::Status VoldNativeService::format(const std::string& volId, const std::string& fsType) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     CHECK_ARGUMENT_ID(volId);
     ACQUIRE_LOCK;
 
@@ -400,7 +400,7 @@
 
 binder::Status VoldNativeService::benchmark(
     const std::string& volId, const android::sp<android::os::IVoldTaskListener>& listener) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     CHECK_ARGUMENT_ID(volId);
     ACQUIRE_LOCK;
 
@@ -413,7 +413,7 @@
 }
 
 binder::Status VoldNativeService::checkEncryption(const std::string& volId) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     CHECK_ARGUMENT_ID(volId);
     ACQUIRE_LOCK;
 
@@ -426,7 +426,7 @@
 binder::Status VoldNativeService::moveStorage(
     const std::string& fromVolId, const std::string& toVolId,
     const android::sp<android::os::IVoldTaskListener>& listener) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     CHECK_ARGUMENT_ID(fromVolId);
     CHECK_ARGUMENT_ID(toVolId);
     ACQUIRE_LOCK;
@@ -444,14 +444,14 @@
 }
 
 binder::Status VoldNativeService::remountUid(int32_t uid, int32_t remountMode) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return translate(VolumeManager::Instance()->remountUid(uid, remountMode));
 }
 
 binder::Status VoldNativeService::mkdirs(const std::string& path) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     CHECK_ARGUMENT_PATH(path);
     ACQUIRE_LOCK;
 
@@ -461,7 +461,7 @@
 binder::Status VoldNativeService::createObb(const std::string& sourcePath,
                                             const std::string& sourceKey, int32_t ownerGid,
                                             std::string* _aidl_return) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     CHECK_ARGUMENT_PATH(sourcePath);
     CHECK_ARGUMENT_HEX(sourceKey);
     ACQUIRE_LOCK;
@@ -471,7 +471,7 @@
 }
 
 binder::Status VoldNativeService::destroyObb(const std::string& volId) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     CHECK_ARGUMENT_ID(volId);
     ACQUIRE_LOCK;
 
@@ -481,7 +481,7 @@
 binder::Status VoldNativeService::createStubVolume(
     const std::string& sourcePath, const std::string& mountPath, const std::string& fsType,
     const std::string& fsUuid, const std::string& fsLabel, std::string* _aidl_return) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     CHECK_ARGUMENT_PATH(sourcePath);
     CHECK_ARGUMENT_PATH(mountPath);
     CHECK_ARGUMENT_HEX(fsUuid);
@@ -494,7 +494,7 @@
 }
 
 binder::Status VoldNativeService::destroyStubVolume(const std::string& volId) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     CHECK_ARGUMENT_ID(volId);
     ACQUIRE_LOCK;
 
@@ -503,7 +503,7 @@
 
 binder::Status VoldNativeService::fstrim(
     int32_t fstrimFlags, const android::sp<android::os::IVoldTaskListener>& listener) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     std::thread([=]() { android::vold::Trim(listener); }).detach();
@@ -512,7 +512,7 @@
 
 binder::Status VoldNativeService::runIdleMaint(
     const android::sp<android::os::IVoldTaskListener>& listener) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     std::thread([=]() { android::vold::RunIdleMaint(listener); }).detach();
@@ -521,7 +521,7 @@
 
 binder::Status VoldNativeService::abortIdleMaint(
     const android::sp<android::os::IVoldTaskListener>& listener) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     std::thread([=]() { android::vold::AbortIdleMaint(listener); }).detach();
@@ -530,14 +530,14 @@
 
 binder::Status VoldNativeService::mountAppFuse(int32_t uid, int32_t mountId,
                                                android::base::unique_fd* _aidl_return) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return translate(VolumeManager::Instance()->mountAppFuse(uid, mountId, _aidl_return));
 }
 
 binder::Status VoldNativeService::unmountAppFuse(int32_t uid, int32_t mountId) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return translate(VolumeManager::Instance()->unmountAppFuse(uid, mountId));
@@ -546,7 +546,7 @@
 binder::Status VoldNativeService::openAppFuseFile(int32_t uid, int32_t mountId, int32_t fileId,
                                                   int32_t flags,
                                                   android::base::unique_fd* _aidl_return) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     int fd = VolumeManager::Instance()->openAppFuseFile(uid, mountId, fileId, flags);
@@ -561,14 +561,14 @@
 }
 
 binder::Status VoldNativeService::fdeCheckPassword(const std::string& password) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     return translate(cryptfs_check_passwd(password.c_str()));
 }
 
 binder::Status VoldNativeService::fdeRestart() {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     // Spawn as thread so init can issue commands back to vold without
@@ -578,7 +578,7 @@
 }
 
 binder::Status VoldNativeService::fdeComplete(int32_t* _aidl_return) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     *_aidl_return = cryptfs_crypto_complete();
@@ -609,7 +609,7 @@
 
 binder::Status VoldNativeService::fdeEnable(int32_t passwordType, const std::string& password,
                                             int32_t encryptionFlags) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     LOG(DEBUG) << "fdeEnable(" << passwordType << ", *, " << encryptionFlags << ")";
@@ -627,21 +627,21 @@
 
 binder::Status VoldNativeService::fdeChangePassword(int32_t passwordType,
                                                     const std::string& password) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     return translate(cryptfs_changepw(passwordType, password.c_str()));
 }
 
 binder::Status VoldNativeService::fdeVerifyPassword(const std::string& password) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     return translate(cryptfs_verify_passwd(password.c_str()));
 }
 
 binder::Status VoldNativeService::fdeGetField(const std::string& key, std::string* _aidl_return) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     char buf[PROPERTY_VALUE_MAX];
@@ -654,14 +654,14 @@
 }
 
 binder::Status VoldNativeService::fdeSetField(const std::string& key, const std::string& value) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     return translate(cryptfs_setfield(key.c_str(), value.c_str()));
 }
 
 binder::Status VoldNativeService::fdeGetPasswordType(int32_t* _aidl_return) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     *_aidl_return = cryptfs_get_password_type();
@@ -669,7 +669,7 @@
 }
 
 binder::Status VoldNativeService::fdeGetPassword(std::string* _aidl_return) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     const char* res = cryptfs_get_password();
@@ -680,7 +680,7 @@
 }
 
 binder::Status VoldNativeService::fdeClearPassword() {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     cryptfs_clear_password();
@@ -688,14 +688,14 @@
 }
 
 binder::Status VoldNativeService::fbeEnable() {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     return translateBool(fscrypt_initialize_systemwide_keys());
 }
 
 binder::Status VoldNativeService::mountDefaultEncrypted() {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     if (!fscrypt_is_native()) {
@@ -707,14 +707,14 @@
 }
 
 binder::Status VoldNativeService::initUser0() {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     return translateBool(fscrypt_init_user0());
 }
 
 binder::Status VoldNativeService::isConvertibleToFbe(bool* _aidl_return) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     *_aidl_return = cryptfs_isConvertibleToFBE() != 0;
@@ -723,7 +723,7 @@
 
 binder::Status VoldNativeService::mountFstab(const std::string& blkDevice,
                                              const std::string& mountPoint) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return translateBool(fscrypt_mount_metadata_encrypted(blkDevice, mountPoint, false));
@@ -731,21 +731,21 @@
 
 binder::Status VoldNativeService::encryptFstab(const std::string& blkDevice,
                                                const std::string& mountPoint) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return translateBool(fscrypt_mount_metadata_encrypted(blkDevice, mountPoint, true));
 }
 
 binder::Status VoldNativeService::createUserKey(int32_t userId, int32_t userSerial, bool ephemeral) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     return translateBool(fscrypt_vold_create_user_key(userId, userSerial, ephemeral));
 }
 
 binder::Status VoldNativeService::destroyUserKey(int32_t userId) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     return translateBool(fscrypt_destroy_user_key(userId));
@@ -754,14 +754,14 @@
 binder::Status VoldNativeService::addUserKeyAuth(int32_t userId, int32_t userSerial,
                                                  const std::string& token,
                                                  const std::string& secret) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     return translateBool(fscrypt_add_user_key_auth(userId, userSerial, token, secret));
 }
 
 binder::Status VoldNativeService::fixateNewestUserKeyAuth(int32_t userId) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     return translateBool(fscrypt_fixate_newest_user_key_auth(userId));
@@ -770,14 +770,14 @@
 binder::Status VoldNativeService::unlockUserKey(int32_t userId, int32_t userSerial,
                                                 const std::string& token,
                                                 const std::string& secret) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     return translateBool(fscrypt_unlock_user_key(userId, userSerial, token, secret));
 }
 
 binder::Status VoldNativeService::lockUserKey(int32_t userId) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_CRYPT_LOCK;
 
     return translateBool(fscrypt_lock_user_key(userId));
@@ -786,7 +786,7 @@
 binder::Status VoldNativeService::prepareUserStorage(const std::unique_ptr<std::string>& uuid,
                                                      int32_t userId, int32_t userSerial,
                                                      int32_t flags) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     std::string empty_string = "";
     auto uuid_ = uuid ? *uuid : empty_string;
     CHECK_ARGUMENT_HEX(uuid_);
@@ -797,7 +797,7 @@
 
 binder::Status VoldNativeService::destroyUserStorage(const std::unique_ptr<std::string>& uuid,
                                                      int32_t userId, int32_t flags) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     std::string empty_string = "";
     auto uuid_ = uuid ? *uuid : empty_string;
     CHECK_ARGUMENT_HEX(uuid_);
@@ -819,14 +819,14 @@
 }
 
 binder::Status VoldNativeService::startCheckpoint(int32_t retry) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return cp_startCheckpoint(retry);
 }
 
 binder::Status VoldNativeService::needsRollback(bool* _aidl_return) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     *_aidl_return = cp_needsRollback();
@@ -834,7 +834,7 @@
 }
 
 binder::Status VoldNativeService::needsCheckpoint(bool* _aidl_return) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     *_aidl_return = cp_needsCheckpoint();
@@ -842,21 +842,21 @@
 }
 
 binder::Status VoldNativeService::commitChanges() {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return cp_commitChanges();
 }
 
 binder::Status VoldNativeService::prepareCheckpoint() {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return cp_prepareCheckpoint();
 }
 
 binder::Status VoldNativeService::restoreCheckpoint(const std::string& mountPoint) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     CHECK_ARGUMENT_PATH(mountPoint);
     ACQUIRE_LOCK;
 
@@ -864,7 +864,7 @@
 }
 
 binder::Status VoldNativeService::restoreCheckpointPart(const std::string& mountPoint, int count) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     CHECK_ARGUMENT_PATH(mountPoint);
     ACQUIRE_LOCK;
 
@@ -872,14 +872,14 @@
 }
 
 binder::Status VoldNativeService::markBootAttempt() {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return cp_markBootAttempt();
 }
 
 binder::Status VoldNativeService::abortChanges(const std::string& message, bool retry) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     cp_abortChanges(message, retry);
@@ -887,25 +887,33 @@
 }
 
 binder::Status VoldNativeService::supportsCheckpoint(bool* _aidl_return) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return cp_supportsCheckpoint(*_aidl_return);
 }
 
 binder::Status VoldNativeService::supportsBlockCheckpoint(bool* _aidl_return) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return cp_supportsBlockCheckpoint(*_aidl_return);
 }
 
 binder::Status VoldNativeService::supportsFileCheckpoint(bool* _aidl_return) {
-    ENFORCE_UID(AID_SYSTEM);
+    ENFORCE_SYSTEM_OR_ROOT;
     ACQUIRE_LOCK;
 
     return cp_supportsFileCheckpoint(*_aidl_return);
 }
 
+binder::Status VoldNativeService::resetCheckpoint() {
+    ENFORCE_SYSTEM_OR_ROOT;
+    ACQUIRE_LOCK;
+
+    cp_resetCheckpoint();
+    return ok();
+}
+
 }  // namespace vold
 }  // namespace android
diff --git a/VoldNativeService.h b/VoldNativeService.h
index 07a0b9f..13137c5 100644
--- a/VoldNativeService.h
+++ b/VoldNativeService.h
@@ -140,6 +140,7 @@
     binder::Status supportsCheckpoint(bool* _aidl_return);
     binder::Status supportsBlockCheckpoint(bool* _aidl_return);
     binder::Status supportsFileCheckpoint(bool* _aidl_return);
+    binder::Status resetCheckpoint();
 };
 
 }  // namespace vold
diff --git a/binder/android/os/IVold.aidl b/binder/android/os/IVold.aidl
index 03fe258..8e5c53d 100644
--- a/binder/android/os/IVold.aidl
+++ b/binder/android/os/IVold.aidl
@@ -116,6 +116,7 @@
     boolean supportsCheckpoint();
     boolean supportsBlockCheckpoint();
     boolean supportsFileCheckpoint();
+    void resetCheckpoint();
 
     @utf8InCpp String createStubVolume(@utf8InCpp String sourcePath,
             @utf8InCpp String mountPath, @utf8InCpp String fsType,
diff --git a/fscrypt_uapi.h b/fscrypt_uapi.h
new file mode 100644
index 0000000..3999036
--- /dev/null
+++ b/fscrypt_uapi.h
@@ -0,0 +1,48 @@
+#ifndef _UAPI_LINUX_FSCRYPT_H
+#define _UAPI_LINUX_FSCRYPT_H
+
+// Definitions for FS_IOC_ADD_ENCRYPTION_KEY and FS_IOC_REMOVE_ENCRYPTION_KEY
+
+// TODO: switch to <linux/fscrypt.h> once it's in Bionic
+
+#ifndef FS_IOC_ADD_ENCRYPTION_KEY
+
+#include <linux/types.h>
+
+#define FSCRYPT_KEY_DESCRIPTOR_SIZE 8
+#define FSCRYPT_KEY_IDENTIFIER_SIZE 16
+
+#define FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR 1
+#define FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER 2
+
+struct fscrypt_key_specifier {
+    __u32 type;
+    __u32 __reserved;
+    union {
+        __u8 __reserved[32];
+        __u8 descriptor[FSCRYPT_KEY_DESCRIPTOR_SIZE];
+        __u8 identifier[FSCRYPT_KEY_IDENTIFIER_SIZE];
+    } u;
+};
+
+struct fscrypt_add_key_arg {
+    struct fscrypt_key_specifier key_spec;
+    __u32 raw_size;
+    __u32 __reserved[9];
+    __u8 raw[];
+};
+
+struct fscrypt_remove_key_arg {
+    struct fscrypt_key_specifier key_spec;
+#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY 0x00000001
+#define FSCRYPT_KEY_REMOVAL_STATUS_FLAG_OTHER_USERS 0x00000002
+    __u32 removal_status_flags;
+    __u32 __reserved[5];
+};
+
+#define FS_IOC_ADD_ENCRYPTION_KEY _IOWR('f', 23, struct fscrypt_add_key_arg)
+#define FS_IOC_REMOVE_ENCRYPTION_KEY _IOWR('f', 24, struct fscrypt_remove_key_arg)
+
+#endif /* FS_IOC_ADD_ENCRYPTION_KEY */
+
+#endif /* _UAPI_LINUX_FSCRYPT_H */
diff --git a/vdc.cpp b/vdc.cpp
index 839e70e..c1b7781 100644
--- a/vdc.cpp
+++ b/vdc.cpp
@@ -147,6 +147,8 @@
         int retry;
         if (!android::base::ParseInt(args[2], &retry)) exit(EINVAL);
         checkStatus(args, vold->abortChanges(args[2], retry != 0));
+    } else if (args[0] == "checkpoint" && args[1] == "resetCheckpoint") {
+        checkStatus(args, vold->resetCheckpoint());
     } else {
         LOG(ERROR) << "Raw commands are no longer supported";
         exit(EINVAL);