diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index 55214f5..7488bda 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -1846,7 +1846,7 @@
         PLOG(ERROR) << "Open failed: " << file;
         return nullptr;
     }
-    if (lock_flags != 0 && flock(fd, lock_flags) < 0) {
+    if (lock_flags != 0 && TEMP_FAILURE_RETRY(flock(fd, lock_flags)) < 0) {
         PLOG(ERROR) << "Acquire flock failed: " << file;
         return nullptr;
     }
@@ -1857,7 +1857,7 @@
 }
 
 SnapshotManager::LockedFile::~LockedFile() {
-    if (flock(fd_, LOCK_UN) < 0) {
+    if (TEMP_FAILURE_RETRY(flock(fd_, LOCK_UN)) < 0) {
         PLOG(ERROR) << "Failed to unlock file: " << path_;
     }
 }
@@ -2520,7 +2520,19 @@
         LOG(INFO) << "EnsureMetadataMounted does nothing in Android mode.";
         return std::unique_ptr<AutoUnmountDevice>(new AutoUnmountDevice());
     }
-    return AutoUnmountDevice::New(device_->GetMetadataDir());
+    auto ret = AutoUnmountDevice::New(device_->GetMetadataDir());
+    if (ret == nullptr) return nullptr;
+
+    // In rescue mode, it is possible to erase and format metadata, but /metadata/ota is not
+    // created to execute snapshot updates. Hence, subsequent calls is likely to fail because
+    // Lock*() fails. By failing early and returning nullptr here, update_engine_sideload can
+    // treat this case as if /metadata is not mounted.
+    if (!LockShared()) {
+        LOG(WARNING) << "/metadata is mounted, but errors occur when acquiring a shared lock. "
+                        "Subsequent calls to SnapshotManager will fail. Unmounting /metadata now.";
+        return nullptr;
+    }
+    return ret;
 }
 
 bool SnapshotManager::HandleImminentDataWipe(const std::function<void()>& callback) {