libsnapshot: Pause snapshot merge during shutdown
If the device is mounted off snapshots, initiate the snapshot-merge
pause.
Additionally, try to umount the partitions which are mounted off snapshots.
Bug: 386142969
Test: Reboot device when snapshot merge is in progress and verify merge
threads are paused
Change-Id: Ide9e33157432e3a8d4e6ba7d4d414270505b8941
Signed-off-by: Akilesh Kailash <akailash@google.com>
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
index 165ecef..e613d54 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
@@ -418,9 +418,16 @@
// first-stage to decide whether to launch snapuserd.
bool IsSnapuserdRequired();
- // This is primarily used to device reboot. If OTA update is in progress,
- // init will avoid killing processes
- bool IsUserspaceSnapshotUpdateInProgress();
+ // This is primarily invoked during device reboot after an OTA update.
+ //
+ // a: Check if the partitions are mounted off snapshots.
+ //
+ // b: Store all dynamic partitions which are mounted off snapshots. This
+ // is used to unmount the partition.
+ bool IsUserspaceSnapshotUpdateInProgress(std::vector<std::string>& dynamic_partitions);
+
+ // Pause the snapshot merge.
+ bool PauseSnapshotMerge();
enum class SnapshotDriver {
DM_SNAPSHOT,
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index 83787df..d456197 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -4687,7 +4687,17 @@
return status.source_build_fingerprint();
}
-bool SnapshotManager::IsUserspaceSnapshotUpdateInProgress() {
+bool SnapshotManager::PauseSnapshotMerge() {
+ auto snapuserd_client = SnapuserdClient::TryConnect(kSnapuserdSocket, 5s);
+ if (snapuserd_client) {
+ // Pause the snapshot-merge
+ return snapuserd_client->PauseMerge();
+ }
+ return false;
+}
+
+bool SnapshotManager::IsUserspaceSnapshotUpdateInProgress(
+ std::vector<std::string>& dynamic_partitions) {
// We cannot grab /metadata/ota lock here as this
// is in reboot path. See b/308900853
//
@@ -4701,18 +4711,22 @@
LOG(ERROR) << "No dm-enabled block device is found.";
return false;
}
+
+ bool is_ota_in_progress = false;
for (auto& partition : dm_block_devices) {
std::string partition_name = partition.first + current_suffix;
DeviceMapper::TargetInfo snap_target;
if (!GetSingleTarget(partition_name, TableQuery::Status, &snap_target)) {
- return false;
+ continue;
}
auto type = DeviceMapper::GetTargetType(snap_target.spec);
+ // Partition is mounted off snapshots
if (type == "user") {
- return true;
+ dynamic_partitions.emplace_back("/" + partition.first);
+ is_ota_in_progress = true;
}
}
- return false;
+ return is_ota_in_progress;
}
bool SnapshotManager::BootFromSnapshotsWithoutSlotSwitch() {
diff --git a/fs_mgr/libsnapshot/snapshot_test.cpp b/fs_mgr/libsnapshot/snapshot_test.cpp
index e04e429..7719a29 100644
--- a/fs_mgr/libsnapshot/snapshot_test.cpp
+++ b/fs_mgr/libsnapshot/snapshot_test.cpp
@@ -3112,8 +3112,10 @@
// thereby interfering with the update and snapshot-merge progress.
// Hence, wait until the update is complete.
auto sm = android::snapshot::SnapshotManager::New();
- while (sm->IsUserspaceSnapshotUpdateInProgress()) {
- LOG(INFO) << "Snapshot update is in progress. Waiting...";
+ std::vector<std::string> snapshot_partitions;
+ while (sm->IsUserspaceSnapshotUpdateInProgress(snapshot_partitions)) {
+ LOG(INFO) << "Waiting for: " << snapshot_partitions.size()
+ << " partitions to finish snapshot-merge";
std::this_thread::sleep_for(std::chrono::milliseconds(1000));
}
diff --git a/init/reboot.cpp b/init/reboot.cpp
index d6e37f7..8b10974 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -394,6 +394,21 @@
}
}
+static void UmountDynamicPartitions(const std::vector<std::string>& dynamic_partitions) {
+ for (auto device : dynamic_partitions) {
+ // Cannot unmount /system
+ if (device == "/system") {
+ continue;
+ }
+ int r = umount2(device.c_str(), MNT_FORCE);
+ if (r == 0) {
+ LOG(INFO) << "Umounted success: " << device;
+ } else {
+ PLOG(WARNING) << "Cannot umount: " << device;
+ }
+ }
+}
+
/* Try umounting all emulated file systems R/W block device cfile systems.
* This will just try umount and give it up if it fails.
* For fs like ext4, this is ok as file system will be marked as unclean shutdown
@@ -408,14 +423,18 @@
Timer t;
std::vector<MountEntry> block_devices;
std::vector<MountEntry> emulated_devices;
+ std::vector<std::string> dynamic_partitions;
if (run_fsck && !FindPartitionsToUmount(&block_devices, &emulated_devices, false)) {
return UMOUNT_STAT_ERROR;
}
auto sm = snapshot::SnapshotManager::New();
bool ota_update_in_progress = false;
- if (sm->IsUserspaceSnapshotUpdateInProgress()) {
- LOG(INFO) << "OTA update in progress";
+ if (sm->IsUserspaceSnapshotUpdateInProgress(dynamic_partitions)) {
+ LOG(INFO) << "OTA update in progress. Pause snapshot merge";
+ if (!sm->PauseSnapshotMerge()) {
+ LOG(ERROR) << "Snapshot-merge pause failed";
+ }
ota_update_in_progress = true;
}
UmountStat stat = UmountPartitions(timeout - t.duration());
@@ -435,6 +454,7 @@
// still not doing fsck when all processes are killed.
//
if (ota_update_in_progress) {
+ UmountDynamicPartitions(dynamic_partitions);
return stat;
}
KillAllProcesses();