diff --git a/fastboot/Android.bp b/fastboot/Android.bp index 43b2ddd67..ce702a08d 100644 --- a/fastboot/Android.bp +++ b/fastboot/Android.bp @@ -183,6 +183,7 @@ cc_binary { ], static_libs: [ + "libc++fs", "libgtest_prod", "libhealthhalutils", "libsnapshot_cow", diff --git a/fs_mgr/libsnapshot/Android.bp b/fs_mgr/libsnapshot/Android.bp index ea92d25e0..3cb412378 100644 --- a/fs_mgr/libsnapshot/Android.bp +++ b/fs_mgr/libsnapshot/Android.bp @@ -264,6 +264,7 @@ cc_defaults { "android.hardware.boot@1.0", "android.hardware.boot@1.1", "libbrotli", + "libc++fs", "libfs_mgr", "libgsi", "libgmock", @@ -297,6 +298,7 @@ cc_binary { ], static_libs: [ "libbrotli", + "libc++fs", "libfstab", "libsnapshot", "libsnapshot_cow", @@ -326,6 +328,7 @@ cc_test { "power_test.cpp", ], static_libs: [ + "libc++fs", "libsnapshot", "update_metadata-protos", ], @@ -355,6 +358,7 @@ cc_defaults { static_libs: [ "libbase", "libbrotli", + "libc++fs", "libchrome", "libcrypto_static", "libcutils", @@ -416,7 +420,7 @@ cc_defaults { "snapuserd_server.cpp", "snapuserd.cpp", "snapuserd_daemon.cpp", - "snapuserd_worker.cpp", + "snapuserd_worker.cpp", ], cflags: [ diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h index 7e74facf3..126e1a0a5 100644 --- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h +++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h @@ -493,6 +493,9 @@ class SnapshotManager final : public ISnapshotManager { // Unmap a COW image device previously mapped with MapCowImage(). bool UnmapCowImage(const std::string& name); + // Unmap a COW and remove it from a MetadataBuilder. + void UnmapAndDeleteCowPartition(MetadataBuilder* current_metadata); + // Unmap and remove all known snapshots. bool RemoveAllSnapshots(LockedFile* lock); @@ -738,6 +741,10 @@ class SnapshotManager final : public ISnapshotManager { // Helper of UpdateUsesCompression bool UpdateUsesCompression(LockedFile* lock); + // Wrapper around libdm, with diagnostics. + bool DeleteDeviceIfExists(const std::string& name, + const std::chrono::milliseconds& timeout_ms = {}); + std::string gsid_dir_; std::string metadata_dir_; std::unique_ptr device_; diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp index a0a1e4f5f..c50435564 100644 --- a/fs_mgr/libsnapshot/snapshot.cpp +++ b/fs_mgr/libsnapshot/snapshot.cpp @@ -21,6 +21,7 @@ #include #include +#include #include #include #include @@ -587,8 +588,7 @@ bool SnapshotManager::MapSourceDevice(LockedFile* lock, const std::string& name, bool SnapshotManager::UnmapSnapshot(LockedFile* lock, const std::string& name) { CHECK(lock); - auto& dm = DeviceMapper::Instance(); - if (!dm.DeleteDeviceIfExists(name)) { + if (!DeleteDeviceIfExists(name)) { LOG(ERROR) << "Could not delete snapshot device: " << name; return false; } @@ -1252,25 +1252,6 @@ bool SnapshotManager::OnSnapshotMergeComplete(LockedFile* lock, const std::strin return true; } -static bool DeleteDmDevice(const std::string& name, const std::chrono::milliseconds& timeout_ms) { - auto start = std::chrono::steady_clock::now(); - auto& dm = DeviceMapper::Instance(); - while (true) { - if (dm.DeleteDeviceIfExists(name)) { - break; - } - auto now = std::chrono::steady_clock::now(); - auto elapsed = std::chrono::duration_cast(now - start); - if (elapsed >= timeout_ms) { - LOG(ERROR) << "DeleteDevice timeout: " << name; - return false; - } - std::this_thread::sleep_for(400ms); - } - - return true; -} - bool SnapshotManager::CollapseSnapshotDevice(const std::string& name, const SnapshotStatus& status) { auto& dm = DeviceMapper::Instance(); @@ -1326,11 +1307,11 @@ bool SnapshotManager::CollapseSnapshotDevice(const std::string& name, UnmapDmUserDevice(name); } auto base_name = GetBaseDeviceName(name); - if (!dm.DeleteDeviceIfExists(base_name)) { + if (!DeleteDeviceIfExists(base_name)) { LOG(ERROR) << "Unable to delete base device for snapshot: " << base_name; } - if (!DeleteDmDevice(GetSourceDeviceName(name), 4000ms)) { + if (!DeleteDeviceIfExists(GetSourceDeviceName(name), 4000ms)) { LOG(ERROR) << "Unable to delete source device for snapshot: " << GetSourceDeviceName(name); } @@ -2083,15 +2064,14 @@ bool SnapshotManager::UnmapPartitionWithSnapshot(LockedFile* lock, return false; } - auto& dm = DeviceMapper::Instance(); auto base_name = GetBaseDeviceName(target_partition_name); - if (!dm.DeleteDeviceIfExists(base_name)) { + if (!DeleteDeviceIfExists(base_name)) { LOG(ERROR) << "Cannot delete base device: " << base_name; return false; } auto source_name = GetSourceDeviceName(target_partition_name); - if (!dm.DeleteDeviceIfExists(source_name)) { + if (!DeleteDeviceIfExists(source_name)) { LOG(ERROR) << "Cannot delete source device: " << source_name; return false; } @@ -2181,7 +2161,7 @@ bool SnapshotManager::UnmapCowDevices(LockedFile* lock, const std::string& name) return false; } - if (!DeleteDmDevice(GetCowName(name), 4000ms)) { + if (!DeleteDeviceIfExists(GetCowName(name), 4000ms)) { LOG(ERROR) << "Cannot unmap: " << GetCowName(name); return false; } @@ -2202,7 +2182,7 @@ bool SnapshotManager::UnmapDmUserDevice(const std::string& snapshot_name) { return true; } - if (!dm.DeleteDeviceIfExists(dm_user_name)) { + if (!DeleteDeviceIfExists(dm_user_name)) { LOG(ERROR) << "Cannot unmap " << dm_user_name; return false; } @@ -2593,11 +2573,10 @@ bool SnapshotManager::ForceLocalImageManager() { return true; } -static void UnmapAndDeleteCowPartition(MetadataBuilder* current_metadata) { - auto& dm = DeviceMapper::Instance(); +void SnapshotManager::UnmapAndDeleteCowPartition(MetadataBuilder* current_metadata) { std::vector to_delete; for (auto* existing_cow_partition : current_metadata->ListPartitionsInGroup(kCowGroupName)) { - if (!dm.DeleteDeviceIfExists(existing_cow_partition->name())) { + if (!DeleteDeviceIfExists(existing_cow_partition->name())) { LOG(WARNING) << existing_cow_partition->name() << " cannot be unmapped and its space cannot be reclaimed"; continue; @@ -3626,5 +3605,71 @@ void SnapshotManager::UpdateCowStats(ISnapshotMergeStats* stats) { stats->set_estimated_cow_size_bytes(estimated_cow_size); } +bool SnapshotManager::DeleteDeviceIfExists(const std::string& name, + const std::chrono::milliseconds& timeout_ms) { + auto& dm = DeviceMapper::Instance(); + auto start = std::chrono::steady_clock::now(); + while (true) { + if (dm.DeleteDeviceIfExists(name)) { + return true; + } + auto now = std::chrono::steady_clock::now(); + auto elapsed = std::chrono::duration_cast(now - start); + if (elapsed >= timeout_ms) { + break; + } + std::this_thread::sleep_for(400ms); + } + + // Try to diagnose why this failed. First get the actual device path. + std::string full_path; + if (!dm.GetDmDevicePathByName(name, &full_path)) { + LOG(ERROR) << "Unable to diagnose DM_DEV_REMOVE failure."; + return false; + } + + // Check for child dm-devices. + std::string block_name = android::base::Basename(full_path); + std::string sysfs_holders = "/sys/class/block/" + block_name + "/holders"; + + std::error_code ec; + std::filesystem::directory_iterator dir_iter(sysfs_holders, ec); + if (auto begin = std::filesystem::begin(dir_iter); begin != std::filesystem::end(dir_iter)) { + LOG(ERROR) << "Child device-mapper device still mapped: " << begin->path(); + return false; + } + + // Check for mounted partitions. + android::fs_mgr::Fstab fstab; + android::fs_mgr::ReadFstabFromFile("/proc/mounts", &fstab); + for (const auto& entry : fstab) { + if (android::base::Basename(entry.blk_device) == block_name) { + LOG(ERROR) << "Partition still mounted: " << entry.mount_point; + return false; + } + } + + // Check for detached mounted partitions. + for (const auto& fs : std::filesystem::directory_iterator("/sys/fs", ec)) { + std::string fs_type = android::base::Basename(fs.path().c_str()); + if (!(fs_type == "ext4" || fs_type == "f2fs")) { + continue; + } + + std::string path = fs.path().c_str() + "/"s + block_name; + if (access(path.c_str(), F_OK) == 0) { + LOG(ERROR) << "Block device was lazily unmounted and is still in-use: " << full_path + << "; possibly open file descriptor or attached loop device."; + return false; + } + } + + LOG(ERROR) << "Device-mapper device " << name << "(" << full_path << ")" + << " still in use." + << " Probably a file descriptor was leaked or held open, or a loop device is" + << " attached."; + return false; +} + } // namespace snapshot } // namespace android