fs_mgr: Add a method for creating one-off partition instances.
fastbootd needs to temporarily map and unmap logical partitions in order
to flash them. To make this easier, this change introduces fs_mgr
methods to create and destroy a single logical partition by name.
Bug: 79173901
Test: N/A
Change-Id: Ic085f2175c26a5edf5f18544012dcfe6d8088f09
diff --git a/fs_mgr/fs_mgr_dm_linear.cpp b/fs_mgr/fs_mgr_dm_linear.cpp
index 28e910b..05e03e1 100644
--- a/fs_mgr/fs_mgr_dm_linear.cpp
+++ b/fs_mgr/fs_mgr_dm_linear.cpp
@@ -79,6 +79,25 @@
return true;
}
+static bool CreateLogicalPartition(const std::string& block_device, const LpMetadata& metadata,
+ const LpMetadataPartition& partition, std::string* path) {
+ DeviceMapper& dm = DeviceMapper::Instance();
+
+ DmTable table;
+ if (!CreateDmTable(block_device, metadata, partition, &table)) {
+ return false;
+ }
+ std::string name = GetPartitionName(partition);
+ if (!dm.CreateDevice(name, table)) {
+ return false;
+ }
+ if (!dm.GetDmDevicePathByName(name, path)) {
+ return false;
+ }
+ LINFO << "Created logical partition " << name << " on device " << *path;
+ return true;
+}
+
bool CreateLogicalPartitions(const std::string& block_device) {
uint32_t slot = SlotNumberForSlotSuffix(fs_mgr_get_slot_suffix());
auto metadata = ReadMetadata(block_device.c_str(), slot);
@@ -86,23 +105,36 @@
LOG(ERROR) << "Could not read partition table.";
return true;
}
-
- DeviceMapper& dm = DeviceMapper::Instance();
for (const auto& partition : metadata->partitions) {
- DmTable table;
- if (!CreateDmTable(block_device, *metadata.get(), partition, &table)) {
- return false;
- }
- std::string name = GetPartitionName(partition);
- if (!dm.CreateDevice(name, table)) {
- return false;
- }
std::string path;
- dm.GetDmDevicePathByName(partition.name, &path);
- LINFO << "Created logical partition " << name << " on device " << path;
+ if (!CreateLogicalPartition(block_device, *metadata.get(), partition, &path)) {
+ LERROR << "Could not create logical partition: " << GetPartitionName(partition);
+ return false;
+ }
}
return true;
}
+bool CreateLogicalPartition(const std::string& block_device, uint32_t metadata_slot,
+ const std::string& partition_name, std::string* path) {
+ auto metadata = ReadMetadata(block_device.c_str(), metadata_slot);
+ if (!metadata) {
+ LOG(ERROR) << "Could not read partition table.";
+ return true;
+ }
+ for (const auto& partition : metadata->partitions) {
+ if (GetPartitionName(partition) == partition_name) {
+ return CreateLogicalPartition(block_device, *metadata.get(), partition, path);
+ }
+ }
+ LERROR << "Could not find any partition with name: " << partition_name;
+ return false;
+}
+
+bool DestroyLogicalPartition(const std::string& name) {
+ DeviceMapper& dm = DeviceMapper::Instance();
+ return dm.DeleteDevice(name);
+}
+
} // namespace fs_mgr
} // namespace android
diff --git a/fs_mgr/include/fs_mgr_dm_linear.h b/fs_mgr/include/fs_mgr_dm_linear.h
index 42af9d0..cac475c 100644
--- a/fs_mgr/include/fs_mgr_dm_linear.h
+++ b/fs_mgr/include/fs_mgr_dm_linear.h
@@ -39,6 +39,15 @@
bool CreateLogicalPartitions(const std::string& block_device);
+// Create a block device for a single logical partition, given metadata and
+// the partition name. On success, a path to the partition's block device is
+// returned.
+bool CreateLogicalPartition(const std::string& block_device, uint32_t metadata_slot,
+ const std::string& partition_name, std::string* path);
+
+// Destroy the block device for a logical partition, by name.
+bool DestroyLogicalPartition(const std::string& name);
+
} // namespace fs_mgr
} // namespace android