Merge changes from topic "libsnapshot_prep"
* changes:
libsnapshot: MapPartitionWithSnapshot cleanup itself if failed
libsnapshot: MapPartitionWithSnapshot: fix timeout
libsnapshot: require ex lock for {Create}{CowImage,Snapshot} / DeleteSnapshot
libsnapshot: Refactor: add {Create,Map,Unmap}CowImage
diff --git a/fs_mgr/libsnapshot/Android.bp b/fs_mgr/libsnapshot/Android.bp
index a54db58..8df9c52 100644
--- a/fs_mgr/libsnapshot/Android.bp
+++ b/fs_mgr/libsnapshot/Android.bp
@@ -49,6 +49,7 @@
name: "libsnapshot_sources",
srcs: [
"snapshot.cpp",
+ "utility.cpp",
],
}
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
index 6f0e804..c41a951 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
@@ -211,25 +211,44 @@
std::unique_ptr<LockedFile> OpenFile(const std::string& file, int open_flags, int lock_flags);
bool Truncate(LockedFile* file);
+ enum class SnapshotState : int { None, Created, Merging, MergeCompleted };
+ static std::string to_string(SnapshotState state);
+
+ // This state is persisted per-snapshot in /metadata/ota/snapshots/.
+ struct SnapshotStatus {
+ SnapshotState state = SnapshotState::None;
+ uint64_t device_size = 0;
+ uint64_t snapshot_size = 0;
+ uint64_t cow_partition_size = 0;
+ uint64_t cow_file_size = 0;
+
+ // These are non-zero when merging.
+ uint64_t sectors_allocated = 0;
+ uint64_t metadata_sectors = 0;
+ };
+
// Create a new snapshot record. This creates the backing COW store and
// persists information needed to map the device. The device can be mapped
// with MapSnapshot().
//
- // |device_size| should be the size of the base_device that will be passed
- // via MapDevice(). |snapshot_size| should be the number of bytes in the
- // base device, starting from 0, that will be snapshotted. The cow_size
+ // |status|.device_size should be the size of the base_device that will be passed
+ // via MapDevice(). |status|.snapshot_size should be the number of bytes in the
+ // base device, starting from 0, that will be snapshotted. |status|.cow_file_size
// should be the amount of space that will be allocated to store snapshot
// deltas.
//
- // If |snapshot_size| < device_size, then the device will always
+ // If |status|.snapshot_size < |status|.device_size, then the device will always
// be mapped with two table entries: a dm-snapshot range covering
// snapshot_size, and a dm-linear range covering the remainder.
//
- // All sizes are specified in bytes, and the device and snapshot sizes
- // must be a multiple of the sector size (512 bytes). |cow_size| will
- // be rounded up to the nearest sector.
- bool CreateSnapshot(LockedFile* lock, const std::string& name, uint64_t device_size,
- uint64_t snapshot_size, uint64_t cow_size);
+ // All sizes are specified in bytes, and the device, snapshot and COW partition sizes
+ // must be a multiple of the sector size (512 bytes). COW file size will be rounded up
+ // to the nearest sector.
+ bool CreateSnapshot(LockedFile* lock, const std::string& name, SnapshotStatus status);
+
+ // |name| should be the base partition name (e.g. "system_a"). Create the
+ // backing COW image using the size previously passed to CreateSnapshot().
+ bool CreateCowImage(LockedFile* lock, const std::string& name);
// Map a snapshot device that was previously created with CreateSnapshot.
// If a merge was previously initiated, the device-mapper table will have a
@@ -239,15 +258,23 @@
// timeout_ms is 0, then no wait will occur and |dev_path| may not yet
// exist on return.
bool MapSnapshot(LockedFile* lock, const std::string& name, const std::string& base_device,
- const std::chrono::milliseconds& timeout_ms, std::string* dev_path);
+ const std::string& cow_device, const std::chrono::milliseconds& timeout_ms,
+ std::string* dev_path);
- // Remove the backing copy-on-write image for the named snapshot. The
+ // Map a COW image that was previous created with CreateCowImage.
+ bool MapCowImage(const std::string& name, const std::chrono::milliseconds& timeout_ms,
+ std::string* cow_image_device);
+
+ // Remove the backing copy-on-write image and snapshot states for the named snapshot. The
// caller is responsible for ensuring that the snapshot is unmapped.
bool DeleteSnapshot(LockedFile* lock, const std::string& name);
// Unmap a snapshot device previously mapped with MapSnapshotDevice().
bool UnmapSnapshot(LockedFile* lock, const std::string& name);
+ // Unmap a COW image device previously mapped with MapCowImage().
+ bool UnmapCowImage(const std::string& name);
+
// Unmap and remove all known snapshots.
bool RemoveAllSnapshots(LockedFile* lock);
@@ -270,22 +297,6 @@
bool WriteUpdateState(LockedFile* file, UpdateState state);
std::string GetStateFilePath() const;
- enum class SnapshotState : int { Created, Merging, MergeCompleted };
- static std::string to_string(SnapshotState state);
-
- // This state is persisted per-snapshot in /metadata/ota/snapshots/.
- struct SnapshotStatus {
- SnapshotState state;
- uint64_t device_size;
- uint64_t snapshot_size;
- uint64_t cow_partition_size;
- uint64_t cow_file_size;
-
- // These are non-zero when merging.
- uint64_t sectors_allocated = 0;
- uint64_t metadata_sectors = 0;
- };
-
// Helpers for merging.
bool SwitchSnapshotToMerge(LockedFile* lock, const std::string& name);
bool RewriteSnapshotDeviceTable(const std::string& dm_name);
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index 7e57421..f00129a 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -36,6 +36,8 @@
#include <libfiemap/image_manager.h>
#include <liblp/liblp.h>
+#include "utility.h"
+
namespace android {
namespace snapshot {
@@ -54,6 +56,7 @@
using android::fs_mgr::GetPartitionName;
using android::fs_mgr::LpMetadata;
using android::fs_mgr::SlotNumberForSlotSuffix;
+using std::chrono::duration_cast;
using namespace std::chrono_literals;
using namespace std::string_literals;
@@ -99,10 +102,14 @@
metadata_dir_ = device_->GetMetadataDir();
}
-static std::string GetCowName(const std::string& snapshot_name) {
+[[maybe_unused]] static std::string GetCowName(const std::string& snapshot_name) {
return snapshot_name + "-cow";
}
+static std::string GetCowImageDeviceName(const std::string& snapshot_name) {
+ return snapshot_name + "-cow-img";
+}
+
static std::string GetBaseDeviceName(const std::string& partition_name) {
return partition_name + "-base";
}
@@ -177,49 +184,60 @@
}
bool SnapshotManager::CreateSnapshot(LockedFile* lock, const std::string& name,
- uint64_t device_size, uint64_t snapshot_size,
- uint64_t cow_size) {
+ SnapshotManager::SnapshotStatus status) {
CHECK(lock);
- if (!EnsureImageManager()) return false;
-
+ CHECK(lock->lock_mode() == LOCK_EX);
// Sanity check these sizes. Like liblp, we guarantee the partition size
// is respected, which means it has to be sector-aligned. (This guarantee
// is useful for locating avb footers correctly). The COW size, however,
// can be arbitrarily larger than specified, so we can safely round it up.
- if (device_size % kSectorSize != 0) {
+ if (status.device_size % kSectorSize != 0) {
LOG(ERROR) << "Snapshot " << name
- << " device size is not a multiple of the sector size: " << device_size;
+ << " device size is not a multiple of the sector size: " << status.device_size;
return false;
}
- if (snapshot_size % kSectorSize != 0) {
- LOG(ERROR) << "Snapshot " << name
- << " snapshot size is not a multiple of the sector size: " << snapshot_size;
+ if (status.snapshot_size % kSectorSize != 0) {
+ LOG(ERROR) << "Snapshot " << name << " snapshot size is not a multiple of the sector size: "
+ << status.snapshot_size;
return false;
}
// Round the COW size up to the nearest sector.
- cow_size += kSectorSize - 1;
- cow_size &= ~(kSectorSize - 1);
+ status.cow_file_size += kSectorSize - 1;
+ status.cow_file_size &= ~(kSectorSize - 1);
- LOG(INFO) << "Snapshot " << name << " will have COW size " << cow_size;
+ status.state = SnapshotState::Created;
+ status.sectors_allocated = 0;
+ status.metadata_sectors = 0;
- // Note, we leave the status file hanging around if we fail to create the
- // actual backing image. This is harmless, since it'll get removed when
- // CancelUpdate is called.
- SnapshotStatus status = {
- .state = SnapshotState::Created,
- .device_size = device_size,
- .snapshot_size = snapshot_size,
- .cow_file_size = cow_size,
- };
if (!WriteSnapshotStatus(lock, name, status)) {
PLOG(ERROR) << "Could not write snapshot status: " << name;
return false;
}
+ return true;
+}
- auto cow_name = GetCowName(name);
+bool SnapshotManager::CreateCowImage(LockedFile* lock, const std::string& name) {
+ CHECK(lock);
+ CHECK(lock->lock_mode() == LOCK_EX);
+ if (!EnsureImageManager()) return false;
+
+ SnapshotStatus status;
+ if (!ReadSnapshotStatus(lock, name, &status)) {
+ return false;
+ }
+
+ // The COW file size should have been rounded up to the nearest sector in CreateSnapshot.
+ // Sanity check this.
+ if (status.cow_file_size % kSectorSize != 0) {
+ LOG(ERROR) << "Snapshot " << name << " COW file size is not a multiple of the sector size: "
+ << status.cow_file_size;
+ return false;
+ }
+
+ std::string cow_image_name = GetCowImageDeviceName(name);
int cow_flags = IImageManager::CREATE_IMAGE_DEFAULT;
- if (!images_->CreateBackingImage(cow_name, cow_size, cow_flags)) {
+ if (!images_->CreateBackingImage(cow_image_name, status.cow_file_size, cow_flags)) {
return false;
}
@@ -238,11 +256,11 @@
// workaround that will be discussed again when the kernel API gets
// consolidated.
ssize_t dm_snap_magic_size = 4; // 32 bit
- return images_->ZeroFillNewImage(cow_name, dm_snap_magic_size);
+ return images_->ZeroFillNewImage(cow_image_name, dm_snap_magic_size);
}
bool SnapshotManager::MapSnapshot(LockedFile* lock, const std::string& name,
- const std::string& base_device,
+ const std::string& base_device, const std::string& cow_device,
const std::chrono::milliseconds& timeout_ms,
std::string* dev_path) {
CHECK(lock);
@@ -288,22 +306,7 @@
uint64_t snapshot_sectors = status.snapshot_size / kSectorSize;
uint64_t linear_sectors = (status.device_size - status.snapshot_size) / kSectorSize;
- auto cow_name = GetCowName(name);
- bool ok;
- std::string cow_dev;
- if (has_local_image_manager_) {
- // If we forced a local image manager, it means we don't have binder,
- // which means first-stage init. We must use device-mapper.
- const auto& opener = device_->GetPartitionOpener();
- ok = images_->MapImageWithDeviceMapper(opener, cow_name, &cow_dev);
- } else {
- ok = images_->MapImageDevice(cow_name, timeout_ms, &cow_dev);
- }
- if (!ok) {
- LOG(ERROR) << "Could not map image device: " << cow_name;
- return false;
- }
auto& dm = DeviceMapper::Instance();
@@ -335,11 +338,10 @@
auto snap_name = (linear_sectors > 0) ? GetSnapshotExtraDeviceName(name) : name;
DmTable table;
- table.Emplace<DmTargetSnapshot>(0, snapshot_sectors, base_device, cow_dev, mode,
+ table.Emplace<DmTargetSnapshot>(0, snapshot_sectors, base_device, cow_device, mode,
kSnapshotChunkSize);
if (!dm.CreateDevice(snap_name, table, dev_path, timeout_ms)) {
LOG(ERROR) << "Could not create snapshot device: " << snap_name;
- images_->UnmapImageDevice(cow_name);
return false;
}
@@ -355,7 +357,6 @@
if (!dm.CreateDevice(name, table, dev_path, timeout_ms)) {
LOG(ERROR) << "Could not create outer snapshot device: " << name;
dm.DeleteDevice(snap_name);
- images_->UnmapImageDevice(cow_name);
return false;
}
}
@@ -366,9 +367,29 @@
return true;
}
+bool SnapshotManager::MapCowImage(const std::string& name,
+ const std::chrono::milliseconds& timeout_ms,
+ std::string* cow_dev) {
+ if (!EnsureImageManager()) return false;
+ auto cow_image_name = GetCowImageDeviceName(name);
+
+ bool ok;
+ if (has_local_image_manager_) {
+ // If we forced a local image manager, it means we don't have binder,
+ // which means first-stage init. We must use device-mapper.
+ const auto& opener = device_->GetPartitionOpener();
+ ok = images_->MapImageWithDeviceMapper(opener, cow_image_name, cow_dev);
+ } else {
+ ok = images_->MapImageDevice(cow_image_name, timeout_ms, cow_dev);
+ }
+ if (!ok) {
+ LOG(ERROR) << "Could not map image device: " << cow_image_name;
+ }
+ return ok;
+}
+
bool SnapshotManager::UnmapSnapshot(LockedFile* lock, const std::string& name) {
CHECK(lock);
- if (!EnsureImageManager()) return false;
SnapshotStatus status;
if (!ReadSnapshotStatus(lock, name, &status)) {
@@ -389,23 +410,25 @@
return false;
}
- auto cow_name = GetCowName(name);
- if (images_->IsImageMapped(cow_name) && !images_->UnmapImageDevice(cow_name)) {
- return false;
- }
return true;
}
+bool SnapshotManager::UnmapCowImage(const std::string& name) {
+ if (!EnsureImageManager()) return false;
+ return images_->UnmapImageIfExists(GetCowImageDeviceName(name));
+}
+
bool SnapshotManager::DeleteSnapshot(LockedFile* lock, const std::string& name) {
CHECK(lock);
+ CHECK(lock->lock_mode() == LOCK_EX);
if (!EnsureImageManager()) return false;
- auto cow_name = GetCowName(name);
- if (images_->BackingImageExists(cow_name)) {
- if (images_->IsImageMapped(cow_name) && !images_->UnmapImageDevice(cow_name)) {
+ auto cow_image_name = GetCowImageDeviceName(name);
+ if (images_->BackingImageExists(cow_image_name)) {
+ if (!images_->UnmapImageIfExists(cow_image_name)) {
return false;
}
- if (!images_->DeleteBackingImage(cow_name)) {
+ if (!images_->DeleteBackingImage(cow_image_name)) {
return false;
}
}
@@ -1153,9 +1176,28 @@
return true;
}
+static std::chrono::milliseconds GetRemainingTime(
+ const std::chrono::milliseconds& timeout,
+ const std::chrono::time_point<std::chrono::steady_clock>& begin) {
+ // If no timeout is specified, execute all commands without specifying any timeout.
+ if (timeout.count() == 0) return std::chrono::milliseconds(0);
+ auto passed_time = std::chrono::steady_clock::now() - begin;
+ auto remaining_time = timeout - duration_cast<std::chrono::milliseconds>(passed_time);
+ if (remaining_time.count() <= 0) {
+ LOG(ERROR) << "MapPartitionWithSnapshot has reached timeout " << timeout.count() << "ms ("
+ << remaining_time.count() << "ms remaining)";
+ // Return min() instead of remaining_time here because 0 is treated as a special value for
+ // no timeout, where the rest of the commands will still be executed.
+ return std::chrono::milliseconds::min();
+ }
+ return remaining_time;
+}
+
bool SnapshotManager::MapPartitionWithSnapshot(LockedFile* lock,
CreateLogicalPartitionParams params,
std::string* path) {
+ auto begin = std::chrono::steady_clock::now();
+
CHECK(lock);
path->clear();
@@ -1207,6 +1249,11 @@
params.device_name = GetBaseDeviceName(params.GetPartitionName());
}
+ AutoDeviceList created_devices;
+
+ // Create the base device for the snapshot, or if there is no snapshot, the
+ // device itself. This device consists of the real blocks in the super
+ // partition that this logical partition occupies.
auto& dm = DeviceMapper::Instance();
std::string ignore_path;
if (!CreateLogicalPartition(params, &ignore_path)) {
@@ -1214,7 +1261,10 @@
<< " as device " << params.GetDeviceName();
return false;
}
+ created_devices.EmplaceBack<AutoUnmapDevice>(&dm, params.GetDeviceName());
+
if (!live_snapshot_status.has_value()) {
+ created_devices.Release();
return true;
}
@@ -1225,10 +1275,35 @@
LOG(ERROR) << "Could not determine major/minor for: " << params.GetDeviceName();
return false;
}
- if (!MapSnapshot(lock, params.GetPartitionName(), base_device, {}, path)) {
+
+ // If there is a timeout specified, compute the remaining time to call Map* functions.
+ // init calls CreateLogicalAndSnapshotPartitions, which has no timeout specified. Still call
+ // Map* functions in this case.
+ auto remaining_time = GetRemainingTime(params.timeout_ms, begin);
+ if (remaining_time.count() < 0) return false;
+
+ std::string cow_image_device;
+ if (!MapCowImage(params.GetPartitionName(), remaining_time, &cow_image_device)) {
+ LOG(ERROR) << "Could not map cow image for partition: " << params.GetPartitionName();
+ return false;
+ }
+ created_devices.EmplaceBack<AutoUnmapImage>(images_.get(),
+ GetCowImageDeviceName(params.partition_name));
+
+ // TODO: map cow linear device here
+ std::string cow_device = cow_image_device;
+
+ remaining_time = GetRemainingTime(params.timeout_ms, begin);
+ if (remaining_time.count() < 0) return false;
+
+ if (!MapSnapshot(lock, params.GetPartitionName(), base_device, cow_device, remaining_time,
+ path)) {
LOG(ERROR) << "Could not map snapshot for partition: " << params.GetPartitionName();
return false;
}
+ // No need to add params.GetPartitionName() to created_devices since it is immediately released.
+
+ created_devices.Release();
LOG(INFO) << "Mapped " << params.GetPartitionName() << " as snapshot device at " << *path;
@@ -1373,7 +1448,9 @@
return false;
}
- if (pieces[0] == "created") {
+ if (pieces[0] == "none") {
+ status->state = SnapshotState::None;
+ } else if (pieces[0] == "created") {
status->state = SnapshotState::Created;
} else if (pieces[0] == "merging") {
status->state = SnapshotState::Merging;
@@ -1381,6 +1458,7 @@
status->state = SnapshotState::MergeCompleted;
} else {
LOG(ERROR) << "Unrecognized state " << pieces[0] << " for snapshot: " << name;
+ return false;
}
if (!android::base::ParseUint(pieces[1], &status->device_size)) {
@@ -1412,6 +1490,8 @@
std::string SnapshotManager::to_string(SnapshotState state) {
switch (state) {
+ case SnapshotState::None:
+ return "none";
case SnapshotState::Created:
return "created";
case SnapshotState::Merging:
diff --git a/fs_mgr/libsnapshot/snapshot_test.cpp b/fs_mgr/libsnapshot/snapshot_test.cpp
index 8487339..429fd8e 100644
--- a/fs_mgr/libsnapshot/snapshot_test.cpp
+++ b/fs_mgr/libsnapshot/snapshot_test.cpp
@@ -106,7 +106,7 @@
"test_partition_b"};
for (const auto& snapshot : snapshots) {
DeleteSnapshotDevice(snapshot);
- DeleteBackingImage(image_manager_, snapshot + "-cow");
+ DeleteBackingImage(image_manager_, snapshot + "-cow-img");
auto status_file = sm->GetSnapshotStatusFilePath(snapshot);
android::base::RemoveFileIfExists(status_file);
@@ -214,6 +214,7 @@
void DeleteSnapshotDevice(const std::string& snapshot) {
DeleteDevice(snapshot);
DeleteDevice(snapshot + "-inner");
+ ASSERT_TRUE(image_manager_->UnmapImageIfExists(snapshot + "-cow-img"));
}
void DeleteDevice(const std::string& device) {
if (dm_.GetState(device) != DmDeviceState::INVALID) {
@@ -231,8 +232,11 @@
ASSERT_TRUE(AcquireLock());
static const uint64_t kDeviceSize = 1024 * 1024;
- ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test-snapshot", kDeviceSize, kDeviceSize,
- kDeviceSize));
+ ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test-snapshot",
+ {.device_size = kDeviceSize,
+ .snapshot_size = kDeviceSize,
+ .cow_file_size = kDeviceSize}));
+ ASSERT_TRUE(sm->CreateCowImage(lock_.get(), "test-snapshot"));
std::vector<std::string> snapshots;
ASSERT_TRUE(sm->ListSnapshots(lock_.get(), &snapshots));
@@ -249,6 +253,7 @@
}
ASSERT_TRUE(sm->UnmapSnapshot(lock_.get(), "test-snapshot"));
+ ASSERT_TRUE(sm->UnmapCowImage("test-snapshot"));
ASSERT_TRUE(sm->DeleteSnapshot(lock_.get(), "test-snapshot"));
}
@@ -256,14 +261,21 @@
ASSERT_TRUE(AcquireLock());
static const uint64_t kDeviceSize = 1024 * 1024;
- ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test-snapshot", kDeviceSize, kDeviceSize,
- kDeviceSize));
+ ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test-snapshot",
+ {.device_size = kDeviceSize,
+ .snapshot_size = kDeviceSize,
+ .cow_file_size = kDeviceSize}));
+ ASSERT_TRUE(sm->CreateCowImage(lock_.get(), "test-snapshot"));
std::string base_device;
ASSERT_TRUE(CreatePartition("base-device", kDeviceSize, &base_device));
+ std::string cow_device;
+ ASSERT_TRUE(sm->MapCowImage("test-snapshot", 10s, &cow_device));
+
std::string snap_device;
- ASSERT_TRUE(sm->MapSnapshot(lock_.get(), "test-snapshot", base_device, 10s, &snap_device));
+ ASSERT_TRUE(sm->MapSnapshot(lock_.get(), "test-snapshot", base_device, cow_device, 10s,
+ &snap_device));
ASSERT_TRUE(android::base::StartsWith(snap_device, "/dev/block/dm-"));
}
@@ -272,14 +284,21 @@
static const uint64_t kSnapshotSize = 1024 * 1024;
static const uint64_t kDeviceSize = 1024 * 1024 * 2;
- ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test-snapshot", kDeviceSize, kSnapshotSize,
- kSnapshotSize));
+ ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test-snapshot",
+ {.device_size = kDeviceSize,
+ .snapshot_size = kSnapshotSize,
+ .cow_file_size = kSnapshotSize}));
+ ASSERT_TRUE(sm->CreateCowImage(lock_.get(), "test-snapshot"));
std::string base_device;
ASSERT_TRUE(CreatePartition("base-device", kDeviceSize, &base_device));
+ std::string cow_device;
+ ASSERT_TRUE(sm->MapCowImage("test-snapshot", 10s, &cow_device));
+
std::string snap_device;
- ASSERT_TRUE(sm->MapSnapshot(lock_.get(), "test-snapshot", base_device, 10s, &snap_device));
+ ASSERT_TRUE(sm->MapSnapshot(lock_.get(), "test-snapshot", base_device, cow_device, 10s,
+ &snap_device));
ASSERT_TRUE(android::base::StartsWith(snap_device, "/dev/block/dm-"));
}
@@ -317,13 +336,18 @@
static const uint64_t kDeviceSize = 1024 * 1024;
- std::string base_device, snap_device;
+ std::string base_device, cow_device, snap_device;
ASSERT_TRUE(CreatePartition("test_partition_a", kDeviceSize));
ASSERT_TRUE(MapUpdatePartitions());
ASSERT_TRUE(dm_.GetDmDevicePathByName("test_partition_b-base", &base_device));
- ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test_partition_b", kDeviceSize, kDeviceSize,
- kDeviceSize));
- ASSERT_TRUE(sm->MapSnapshot(lock_.get(), "test_partition_b", base_device, 10s, &snap_device));
+ ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test_partition_b",
+ {.device_size = kDeviceSize,
+ .snapshot_size = kDeviceSize,
+ .cow_file_size = kDeviceSize}));
+ ASSERT_TRUE(sm->CreateCowImage(lock_.get(), "test_partition_b"));
+ ASSERT_TRUE(sm->MapCowImage("test_partition_b", 10s, &cow_device));
+ ASSERT_TRUE(sm->MapSnapshot(lock_.get(), "test_partition_b", base_device, cow_device, 10s,
+ &snap_device));
std::string test_string = "This is a test string.";
{
@@ -375,16 +399,21 @@
ASSERT_TRUE(AcquireLock());
static const uint64_t kDeviceSize = 1024 * 1024;
- ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test-snapshot", kDeviceSize, kDeviceSize,
- kDeviceSize));
+ ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test-snapshot",
+ {.device_size = kDeviceSize,
+ .snapshot_size = kDeviceSize,
+ .cow_file_size = kDeviceSize}));
+ ASSERT_TRUE(sm->CreateCowImage(lock_.get(), "test-snapshot"));
- std::string base_device, snap_device;
+ std::string base_device, cow_device, snap_device;
ASSERT_TRUE(CreatePartition("base-device", kDeviceSize, &base_device));
- ASSERT_TRUE(sm->MapSnapshot(lock_.get(), "test-snapshot", base_device, 10s, &snap_device));
+ ASSERT_TRUE(sm->MapCowImage("test-snapshot", 10s, &cow_device));
+ ASSERT_TRUE(sm->MapSnapshot(lock_.get(), "test-snapshot", base_device, cow_device, 10s,
+ &snap_device));
// Keep an open handle to the cow device. This should cause the merge to
// be incomplete.
- auto cow_path = android::base::GetProperty("gsid.mapped_image.test-snapshot-cow", "");
+ auto cow_path = android::base::GetProperty("gsid.mapped_image.test-snapshot-cow-img", "");
unique_fd fd(open(cow_path.c_str(), O_RDONLY | O_CLOEXEC));
ASSERT_GE(fd, 0);
@@ -399,12 +428,18 @@
// COW cannot be removed due to open fd, so expect a soft failure.
ASSERT_EQ(sm->ProcessUpdateState(), UpdateState::MergeNeedsReboot);
+ // Release the handle to the COW device to fake a reboot.
+ fd.reset();
+ // Wait 1s, otherwise DeleteSnapshotDevice may fail with EBUSY.
+ sleep(1);
// Forcefully delete the snapshot device, so it looks like we just rebooted.
DeleteSnapshotDevice("test-snapshot");
// Map snapshot should fail now, because we're in a merge-complete state.
ASSERT_TRUE(AcquireLock());
- ASSERT_FALSE(sm->MapSnapshot(lock_.get(), "test-snapshot", base_device, 10s, &snap_device));
+ ASSERT_TRUE(sm->MapCowImage("test-snapshot", 10s, &cow_device));
+ ASSERT_FALSE(sm->MapSnapshot(lock_.get(), "test-snapshot", base_device, cow_device, 10s,
+ &snap_device));
// Release everything and now the merge should complete.
fd = {};
@@ -423,8 +458,11 @@
ASSERT_TRUE(CreatePartition("test_partition_a", kDeviceSize));
ASSERT_TRUE(MapUpdatePartitions());
- ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test_partition_b", kDeviceSize, kDeviceSize,
- kDeviceSize));
+ ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test_partition_b",
+ {.device_size = kDeviceSize,
+ .snapshot_size = kDeviceSize,
+ .cow_file_size = kDeviceSize}));
+ ASSERT_TRUE(sm->CreateCowImage(lock_.get(), "test_partition_b"));
// Simulate a reboot into the new slot.
lock_ = nullptr;
@@ -462,8 +500,11 @@
ASSERT_TRUE(CreatePartition("test_partition_a", kDeviceSize));
ASSERT_TRUE(MapUpdatePartitions());
- ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test_partition_b", kDeviceSize, kDeviceSize,
- kDeviceSize));
+ ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test_partition_b",
+ {.device_size = kDeviceSize,
+ .snapshot_size = kDeviceSize,
+ .cow_file_size = kDeviceSize}));
+ ASSERT_TRUE(sm->CreateCowImage(lock_.get(), "test_partition_b"));
// Simulate a reboot into the new slot.
lock_ = nullptr;
@@ -507,8 +548,11 @@
ASSERT_TRUE(CreatePartition("test_partition_a", kDeviceSize));
ASSERT_TRUE(MapUpdatePartitions());
- ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test_partition_b", kDeviceSize, kDeviceSize,
- kDeviceSize));
+ ASSERT_TRUE(sm->CreateSnapshot(lock_.get(), "test_partition_b",
+ {.device_size = kDeviceSize,
+ .snapshot_size = kDeviceSize,
+ .cow_file_size = kDeviceSize}));
+ ASSERT_TRUE(sm->CreateCowImage(lock_.get(), "test_partition_b"));
// Simulate a reboot into the new slot.
lock_ = nullptr;
@@ -527,7 +571,7 @@
// Now, reflash super. Note that we haven't called ProcessUpdateState, so the
// status is still Merging.
DeleteSnapshotDevice("test_partition_b");
- ASSERT_TRUE(init->image_manager()->UnmapImageDevice("test_partition_b-cow"));
+ ASSERT_TRUE(init->image_manager()->UnmapImageIfExists("test_partition_b-cow-img"));
FormatFakeSuper();
ASSERT_TRUE(CreatePartition("test_partition_b", kDeviceSize));
ASSERT_TRUE(init->NeedSnapshotsInFirstStageMount());
diff --git a/fs_mgr/libsnapshot/utility.cpp b/fs_mgr/libsnapshot/utility.cpp
new file mode 100644
index 0000000..164b472
--- /dev/null
+++ b/fs_mgr/libsnapshot/utility.cpp
@@ -0,0 +1,56 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "utility.h"
+
+#include <android-base/logging.h>
+#include <android-base/strings.h>
+
+namespace android {
+namespace snapshot {
+
+void AutoDevice::Release() {
+ name_.clear();
+}
+
+AutoDeviceList::~AutoDeviceList() {
+ // Destroy devices in the reverse order because newer devices may have dependencies
+ // on older devices.
+ for (auto it = devices_.rbegin(); it != devices_.rend(); ++it) {
+ it->reset();
+ }
+}
+
+void AutoDeviceList::Release() {
+ for (auto&& p : devices_) {
+ p->Release();
+ }
+}
+
+AutoUnmapDevice::~AutoUnmapDevice() {
+ if (name_.empty()) return;
+ if (!dm_->DeleteDeviceIfExists(name_)) {
+ LOG(ERROR) << "Failed to auto unmap device " << name_;
+ }
+}
+
+AutoUnmapImage::~AutoUnmapImage() {
+ if (name_.empty()) return;
+ if (!images_->UnmapImageIfExists(name_)) {
+ LOG(ERROR) << "Failed to auto unmap cow image " << name_;
+ }
+}
+
+} // namespace snapshot
+} // namespace android
diff --git a/fs_mgr/libsnapshot/utility.h b/fs_mgr/libsnapshot/utility.h
new file mode 100644
index 0000000..cbab472
--- /dev/null
+++ b/fs_mgr/libsnapshot/utility.h
@@ -0,0 +1,85 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include <string>
+
+#include <android-base/macros.h>
+#include <libdm/dm.h>
+#include <libfiemap/image_manager.h>
+
+namespace android {
+namespace snapshot {
+
+struct AutoDevice {
+ virtual ~AutoDevice(){};
+ void Release();
+
+ protected:
+ AutoDevice(const std::string& name) : name_(name) {}
+ std::string name_;
+
+ private:
+ DISALLOW_COPY_AND_ASSIGN(AutoDevice);
+ AutoDevice(AutoDevice&& other) = delete;
+};
+
+// A list of devices we created along the way.
+// - Whenever a device is created that is subject to GC'ed at the end of
+// this function, add it to this list.
+// - If any error has occurred, the list is destroyed, and all these devices
+// are cleaned up.
+// - Upon success, Release() should be called so that the created devices
+// are kept.
+struct AutoDeviceList {
+ ~AutoDeviceList();
+ template <typename T, typename... Args>
+ void EmplaceBack(Args&&... args) {
+ devices_.emplace_back(std::make_unique<T>(std::forward<Args>(args)...));
+ }
+ void Release();
+
+ private:
+ std::vector<std::unique_ptr<AutoDevice>> devices_;
+};
+
+// Automatically unmap a device upon deletion.
+struct AutoUnmapDevice : AutoDevice {
+ // On destruct, delete |name| from device mapper.
+ AutoUnmapDevice(android::dm::DeviceMapper* dm, const std::string& name)
+ : AutoDevice(name), dm_(dm) {}
+ AutoUnmapDevice(AutoUnmapDevice&& other) = default;
+ ~AutoUnmapDevice();
+
+ private:
+ DISALLOW_COPY_AND_ASSIGN(AutoUnmapDevice);
+ android::dm::DeviceMapper* dm_ = nullptr;
+};
+
+// Automatically unmap an image upon deletion.
+struct AutoUnmapImage : AutoDevice {
+ // On destruct, delete |name| from image manager.
+ AutoUnmapImage(android::fiemap::IImageManager* images, const std::string& name)
+ : AutoDevice(name), images_(images) {}
+ AutoUnmapImage(AutoUnmapImage&& other) = default;
+ ~AutoUnmapImage();
+
+ private:
+ DISALLOW_COPY_AND_ASSIGN(AutoUnmapImage);
+ android::fiemap::IImageManager* images_ = nullptr;
+};
+
+} // namespace snapshot
+} // namespace android