diff --git a/trusty/storage/interface/include/trusty/interface/storage.h b/trusty/storage/interface/include/trusty/interface/storage.h
index b196d88..3f1dcb8 100644
--- a/trusty/storage/interface/include/trusty/interface/storage.h
+++ b/trusty/storage/interface/include/trusty/interface/storage.h
@@ -112,26 +112,30 @@
 
 /**
  * enum storage_msg_flag - protocol-level flags in struct storage_msg
- * @STORAGE_MSG_FLAG_BATCH:             if set, command belongs to a batch transaction.
- *                                      No response will be sent by the server until
- *                                      it receives a command with this flag unset, at
- *                                      which point a cummulative result for all messages
- *                                      sent with STORAGE_MSG_FLAG_BATCH will be sent.
- *                                      This is only supported by the non-secure disk proxy
- *                                      server.
- * @STORAGE_MSG_FLAG_PRE_COMMIT:        if set, indicates that server need to commit
- *                                      pending changes before processing this message.
- * @STORAGE_MSG_FLAG_POST_COMMIT:       if set, indicates that server need to commit
- *                                      pending changes after processing this message.
- * @STORAGE_MSG_FLAG_TRANSACT_COMPLETE: if set, indicates that server need to commit
- *                                      current transaction after processing this message.
- *                                      It is an alias for STORAGE_MSG_FLAG_POST_COMMIT.
+ * @STORAGE_MSG_FLAG_BATCH:                 if set, command belongs to a batch transaction.
+ *                                          No response will be sent by the server until
+ *                                          it receives a command with this flag unset, at
+ *                                          which point a cumulative result for all messages
+ *                                          sent with STORAGE_MSG_FLAG_BATCH will be sent.
+ *                                          This is only supported by the non-secure disk proxy
+ *                                          server.
+ * @STORAGE_MSG_FLAG_PRE_COMMIT:            if set, indicates that server need to commit
+ *                                          pending changes before processing this message.
+ * @STORAGE_MSG_FLAG_POST_COMMIT:           if set, indicates that server need to commit
+ *                                          pending changes after processing this message.
+ * @STORAGE_MSG_FLAG_TRANSACT_COMPLETE:     if set, indicates that server need to commit
+ *                                          current transaction after processing this message.
+ *                                          It is an alias for STORAGE_MSG_FLAG_POST_COMMIT.
+ * @STORAGE_MSG_FLAG_PRE_COMMIT_CHECKPOINT: if set, indicates that server needs to ensure
+ *                                          that there is not a pending checkpoint for
+ *                                          userdata before processing this message.
  */
 enum storage_msg_flag {
-	STORAGE_MSG_FLAG_BATCH = 0x1,
-	STORAGE_MSG_FLAG_PRE_COMMIT = 0x2,
-	STORAGE_MSG_FLAG_POST_COMMIT = 0x4,
-	STORAGE_MSG_FLAG_TRANSACT_COMPLETE = STORAGE_MSG_FLAG_POST_COMMIT,
+    STORAGE_MSG_FLAG_BATCH = 0x1,
+    STORAGE_MSG_FLAG_PRE_COMMIT = 0x2,
+    STORAGE_MSG_FLAG_POST_COMMIT = 0x4,
+    STORAGE_MSG_FLAG_TRANSACT_COMPLETE = STORAGE_MSG_FLAG_POST_COMMIT,
+    STORAGE_MSG_FLAG_PRE_COMMIT_CHECKPOINT = 0x8,
 };
 
 /*
diff --git a/trusty/storage/proxy/Android.bp b/trusty/storage/proxy/Android.bp
index d67089f..38d8685 100644
--- a/trusty/storage/proxy/Android.bp
+++ b/trusty/storage/proxy/Android.bp
@@ -23,6 +23,7 @@
     vendor: true,
 
     srcs: [
+        "checkpoint_handling.cpp",
         "ipc.c",
         "rpmb.c",
         "storage.c",
@@ -30,12 +31,14 @@
     ],
 
     shared_libs: [
+        "libbase",
         "liblog",
         "libhardware_legacy",
     ],
     header_libs: ["libcutils_headers"],
 
     static_libs: [
+        "libfstab",
         "libtrustystorageinterface",
         "libtrusty",
     ],
diff --git a/trusty/storage/proxy/checkpoint_handling.cpp b/trusty/storage/proxy/checkpoint_handling.cpp
new file mode 100644
index 0000000..6c2fd36
--- /dev/null
+++ b/trusty/storage/proxy/checkpoint_handling.cpp
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "checkpoint_handling.h"
+#include "log.h"
+
+#include <fstab/fstab.h>
+#include <cstring>
+#include <string>
+
+namespace {
+
+bool checkpointingDoneForever = false;
+
+}  // namespace
+
+int is_data_checkpoint_active(bool* active) {
+    if (!active) {
+        ALOGE("active out parameter is null");
+        return 0;
+    }
+
+    *active = false;
+
+    if (checkpointingDoneForever) {
+        return 0;
+    }
+
+    android::fs_mgr::Fstab procMounts;
+    bool success = android::fs_mgr::ReadFstabFromFile("/proc/mounts", &procMounts);
+    if (!success) {
+        ALOGE("Could not parse /proc/mounts\n");
+        /* Really bad. Tell the caller to abort the write. */
+        return -1;
+    }
+
+    android::fs_mgr::FstabEntry* dataEntry =
+            android::fs_mgr::GetEntryForMountPoint(&procMounts, "/data");
+    if (dataEntry == NULL) {
+        ALOGE("/data is not mounted yet\n");
+        return 0;
+    }
+
+    /* We can't handle e.g., ext4. Nothing we can do about it for now. */
+    if (dataEntry->fs_type != "f2fs") {
+        ALOGW("Checkpoint status not supported for filesystem %s\n", dataEntry->fs_type.c_str());
+        checkpointingDoneForever = true;
+        return 0;
+    }
+
+    /*
+     * The data entry looks like "... blah,checkpoint=disable:0,blah ...".
+     * checkpoint=disable means checkpointing is on (yes, arguably reversed).
+     */
+    size_t checkpointPos = dataEntry->fs_options.find("checkpoint=disable");
+    if (checkpointPos == std::string::npos) {
+        /* Assumption is that once checkpointing turns off, it stays off */
+        checkpointingDoneForever = true;
+    } else {
+        *active = true;
+    }
+
+    return 0;
+}
diff --git a/trusty/storage/proxy/checkpoint_handling.h b/trusty/storage/proxy/checkpoint_handling.h
new file mode 100644
index 0000000..f1bf27c
--- /dev/null
+++ b/trusty/storage/proxy/checkpoint_handling.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * is_data_checkpoint_active() - Check for an active, uncommitted checkpoint of
+ * /data. If a checkpoint is active, storage should not commit any
+ * rollback-protected writes to /data.
+ * @active: Out parameter that will be set to the result of the check.
+ *
+ * Return: 0 if active was set and is valid, non-zero otherwise.
+ */
+int is_data_checkpoint_active(bool* active);
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/trusty/storage/proxy/proxy.c b/trusty/storage/proxy/proxy.c
index e230941..c690a28 100644
--- a/trusty/storage/proxy/proxy.c
+++ b/trusty/storage/proxy/proxy.c
@@ -26,6 +26,7 @@
 
 #include <cutils/android_filesystem_config.h>
 
+#include "checkpoint_handling.h"
 #include "ipc.h"
 #include "log.h"
 #include "rpmb.h"
@@ -130,6 +131,21 @@
         }
     }
 
+    if (msg->flags & STORAGE_MSG_FLAG_PRE_COMMIT_CHECKPOINT) {
+        bool is_checkpoint_active = false;
+
+        rc = is_data_checkpoint_active(&is_checkpoint_active);
+        if (rc != 0) {
+            ALOGE("is_data_checkpoint_active failed in an unexpected way. Aborting.\n");
+            msg->result = STORAGE_ERR_GENERIC;
+            return ipc_respond(msg, NULL, 0);
+        } else if (is_checkpoint_active) {
+            ALOGE("Checkpoint in progress, dropping write ...\n");
+            msg->result = STORAGE_ERR_GENERIC;
+            return ipc_respond(msg, NULL, 0);
+        }
+    }
+
     switch (msg->cmd) {
         case STORAGE_FILE_DELETE:
             rc = storage_file_delete(msg, req, req_len);