diff --git a/fs_mgr/liblp/builder.cpp b/fs_mgr/liblp/builder.cpp
index 07f9d66..07e3c8a 100644
--- a/fs_mgr/liblp/builder.cpp
+++ b/fs_mgr/liblp/builder.cpp
@@ -212,7 +212,7 @@
     sABOverrideValue = ab_device;
 }
 
-MetadataBuilder::MetadataBuilder() : auto_slot_suffixing_(false) {
+MetadataBuilder::MetadataBuilder() : auto_slot_suffixing_(false), ignore_slot_suffixing_(false) {
     memset(&geometry_, 0, sizeof(geometry_));
     geometry_.magic = LP_METADATA_GEOMETRY_MAGIC;
     geometry_.struct_size = sizeof(geometry_);
@@ -436,7 +436,7 @@
         LERROR << "Could not find partition group: " << group_name;
         return nullptr;
     }
-    if (IsABDevice() && !auto_slot_suffixing_ && name != "scratch" &&
+    if (IsABDevice() && !auto_slot_suffixing_ && name != "scratch" && !ignore_slot_suffixing_ &&
         GetPartitionSlotSuffix(name).empty()) {
         LERROR << "Unsuffixed partition not allowed on A/B device: " << name;
         return nullptr;
@@ -972,6 +972,10 @@
     auto_slot_suffixing_ = true;
 }
 
+void MetadataBuilder::IgnoreSlotSuffixing() {
+    ignore_slot_suffixing_ = true;
+}
+
 bool MetadataBuilder::IsABDevice() const {
     if (sABOverrideSet) {
         return sABOverrideValue;
@@ -983,5 +987,18 @@
     return GetBlockDevicePartitionName(block_devices_[0]) != LP_METADATA_DEFAULT_PARTITION_NAME;
 }
 
+bool MetadataBuilder::AddLinearExtent(Partition* partition, const std::string& block_device,
+                                      uint64_t num_sectors, uint64_t physical_sector) {
+    uint32_t device_index;
+    if (!FindBlockDeviceByName(block_device, &device_index)) {
+        LERROR << "Could not find backing block device for extent: " << block_device;
+        return false;
+    }
+
+    auto extent = std::make_unique<LinearExtent>(num_sectors, device_index, physical_sector);
+    partition->AddExtent(std::move(extent));
+    return true;
+}
+
 }  // namespace fs_mgr
 }  // namespace android
diff --git a/fs_mgr/liblp/include/liblp/builder.h b/fs_mgr/liblp/include/liblp/builder.h
index f477b4b..57cce21 100644
--- a/fs_mgr/liblp/include/liblp/builder.h
+++ b/fs_mgr/liblp/include/liblp/builder.h
@@ -219,6 +219,10 @@
     // Find a group by name. If no group is found, nullptr is returned.
     PartitionGroup* FindGroup(const std::string& name);
 
+    // Add a predetermined extent to a partition.
+    bool AddLinearExtent(Partition* partition, const std::string& block_device,
+                         uint64_t num_sectors, uint64_t physical_sector);
+
     // Grow or shrink a partition to the requested size. This size will be
     // rounded UP to the nearest block (512 bytes).
     //
@@ -244,6 +248,9 @@
     // Set the LP_METADATA_AUTO_SLOT_SUFFIXING flag.
     void SetAutoSlotSuffixing();
 
+    // If set, checks for slot suffixes will be ignored internally.
+    void IgnoreSlotSuffixing();
+
     bool GetBlockDeviceInfo(const std::string& partition_name, BlockDeviceInfo* info) const;
     bool UpdateBlockDeviceInfo(const std::string& partition_name, const BlockDeviceInfo& info);
 
@@ -306,6 +313,7 @@
     std::vector<std::unique_ptr<PartitionGroup>> groups_;
     std::vector<LpMetadataBlockDevice> block_devices_;
     bool auto_slot_suffixing_;
+    bool ignore_slot_suffixing_;
 };
 
 // Read BlockDeviceInfo for a given block device. This always returns false
diff --git a/init/devices.cpp b/init/devices.cpp
index 45b17a2..1a77ba1 100644
--- a/init/devices.cpp
+++ b/init/devices.cpp
@@ -320,6 +320,7 @@
 
     auto link_path = "/dev/block/" + type + "/" + device;
 
+    bool is_boot_device = boot_devices_.find(device) != boot_devices_.end();
     if (!uevent.partition_name.empty()) {
         std::string partition_name_sanitized(uevent.partition_name);
         SanitizePartitionName(&partition_name_sanitized);
@@ -329,9 +330,13 @@
         }
         links.emplace_back(link_path + "/by-name/" + partition_name_sanitized);
         // Adds symlink: /dev/block/by-name/<partition_name>.
-        if (boot_devices_.find(device) != boot_devices_.end()) {
+        if (is_boot_device) {
             links.emplace_back("/dev/block/by-name/" + partition_name_sanitized);
         }
+    } else if (is_boot_device) {
+        // If we don't have a partition name but we are a partition on a boot device, create a
+        // symlink of /dev/block/by-name/<device_name> for symmetry.
+        links.emplace_back("/dev/block/by-name/" + uevent.device_name);
     }
 
     auto last_slash = uevent.path.rfind('/');