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-rw-r--r--fs_mgr/libsnapshot/Android.bp33
-rw-r--r--fs_mgr/libsnapshot/include/libsnapshot/snapshot.h5
-rw-r--r--fs_mgr/libsnapshot/snapshot.cpp7
-rw-r--r--fs_mgr/libsnapshot/snapshot_fuzz.cpp2
-rw-r--r--fs_mgr/libsnapshot/snapshot_fuzz_utils.h4
-rw-r--r--fs_mgr/libsnapshot/snapshot_metadata_updater.cpp9
-rw-r--r--fs_mgr/libsnapshot/snapuserd.cpp126
7 files changed, 172 insertions, 14 deletions
diff --git a/fs_mgr/libsnapshot/Android.bp b/fs_mgr/libsnapshot/Android.bp
index 95301ff71a..eaef180377 100644
--- a/fs_mgr/libsnapshot/Android.bp
+++ b/fs_mgr/libsnapshot/Android.bp
@@ -310,3 +310,36 @@ cc_test {
auto_gen_config: true,
require_root: true,
}
+
+cc_defaults {
+ name: "snapuserd_defaults",
+ srcs: [
+ "snapuserd.cpp",
+ ],
+
+ cflags: [
+ "-Wall",
+ "-Werror"
+ ],
+
+ static_libs: [
+ "libbase",
+ "liblog",
+ "libdm",
+ ],
+}
+
+cc_binary {
+ name: "snapuserd",
+ defaults: ["snapuserd_defaults"],
+}
+
+cc_binary {
+ name: "snapuserd_ramdisk",
+ stem: "snapuserd",
+ defaults: ["snapuserd_defaults"],
+
+ ramdisk: true,
+ static_executable: true,
+ system_shared_libs: [],
+}
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
index 3c2c77683b..a4a31507ee 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
@@ -553,9 +553,8 @@ class SnapshotManager final : public ISnapshotManager {
// This should only be called in recovery.
bool UnmapAllPartitions();
- // Sanity check no snapshot overflows. Note that this returns false negatives if the snapshot
- // overflows, then is remapped and not written afterwards. Hence, the function may only serve
- // as a sanity check.
+ // Check no snapshot overflows. Note that this returns false negatives if the snapshot
+ // overflows, then is remapped and not written afterwards.
bool EnsureNoOverflowSnapshot(LockedFile* lock);
enum class Slot { Unknown, Source, Target };
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index 7488bdaca8..b49f99ea45 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -300,9 +300,9 @@ bool SnapshotManager::CreateSnapshot(LockedFile* lock, SnapshotStatus* status) {
LOG(ERROR) << "SnapshotStatus has no name.";
return false;
}
- // 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 file size, however,
+ // 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 file size, however,
// can be arbitrarily larger than specified, so we can safely round it up.
if (status->device_size() % kSectorSize != 0) {
LOG(ERROR) << "Snapshot " << status->name()
@@ -351,7 +351,6 @@ Return SnapshotManager::CreateCowImage(LockedFile* lock, const std::string& name
}
// 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();
diff --git a/fs_mgr/libsnapshot/snapshot_fuzz.cpp b/fs_mgr/libsnapshot/snapshot_fuzz.cpp
index 5b145c31f2..aced3edf58 100644
--- a/fs_mgr/libsnapshot/snapshot_fuzz.cpp
+++ b/fs_mgr/libsnapshot/snapshot_fuzz.cpp
@@ -141,7 +141,7 @@ SNAPSHOT_FUZZ_FUNCTION(RecoveryCreateSnapshotDevicesWithMetadata, CreateResult,
const RecoveryCreateSnapshotDevicesArgs& args) {
std::unique_ptr<AutoDevice> device;
if (args.has_metadata_device_object()) {
- device = std::make_unique<DummyAutoDevice>(args.metadata_mounted());
+ device = std::make_unique<NoOpAutoDevice>(args.metadata_mounted());
}
return snapshot->RecoveryCreateSnapshotDevices(device);
}
diff --git a/fs_mgr/libsnapshot/snapshot_fuzz_utils.h b/fs_mgr/libsnapshot/snapshot_fuzz_utils.h
index fa327b8a74..5319e69de0 100644
--- a/fs_mgr/libsnapshot/snapshot_fuzz_utils.h
+++ b/fs_mgr/libsnapshot/snapshot_fuzz_utils.h
@@ -35,9 +35,9 @@ namespace android::snapshot {
class AutoMemBasedDir;
class SnapshotFuzzDeviceInfo;
-class DummyAutoDevice : public AutoDevice {
+class NoOpAutoDevice : public AutoDevice {
public:
- DummyAutoDevice(bool mounted) : AutoDevice(mounted ? "dummy" : "") {}
+ NoOpAutoDevice(bool mounted) : AutoDevice(mounted ? "no_op" : "") {}
};
struct SnapshotTestModule {
diff --git a/fs_mgr/libsnapshot/snapshot_metadata_updater.cpp b/fs_mgr/libsnapshot/snapshot_metadata_updater.cpp
index 051584c341..17a0c96a89 100644
--- a/fs_mgr/libsnapshot/snapshot_metadata_updater.cpp
+++ b/fs_mgr/libsnapshot/snapshot_metadata_updater.cpp
@@ -39,6 +39,8 @@ namespace snapshot {
SnapshotMetadataUpdater::SnapshotMetadataUpdater(MetadataBuilder* builder, uint32_t target_slot,
const DeltaArchiveManifest& manifest)
: builder_(builder), target_suffix_(SlotSuffixForSlotNumber(target_slot)) {
+ partial_update_ = manifest.partial_update();
+
if (!manifest.has_dynamic_partition_metadata()) {
return;
}
@@ -63,7 +65,6 @@ SnapshotMetadataUpdater::SnapshotMetadataUpdater(MetadataBuilder* builder, uint3
}
}
- partial_update_ = manifest.partial_update();
}
bool SnapshotMetadataUpdater::ShrinkPartitions() const {
@@ -173,9 +174,9 @@ bool SnapshotMetadataUpdater::DeleteGroups() const {
if (iter != groups_.end()) {
continue;
}
- // Update package metadata doesn't have this group. Before deleting it, sanity check that it
- // doesn't have any partitions left. Update metadata shouldn't assign any partitions to this
- // group, so all partitions that originally belong to this group should be moved by
+ // Update package metadata doesn't have this group. Before deleting it, check that it
+ // doesn't have any partitions left. Update metadata shouldn't assign any partitions to
+ // this group, so all partitions that originally belong to this group should be moved by
// MovePartitionsToDefault at this point.
auto existing_partitions_in_group = builder_->ListPartitionsInGroup(existing_group_name);
if (!existing_partitions_in_group.empty()) {
diff --git a/fs_mgr/libsnapshot/snapuserd.cpp b/fs_mgr/libsnapshot/snapuserd.cpp
new file mode 100644
index 0000000000..a6ff4fd046
--- /dev/null
+++ b/fs_mgr/libsnapshot/snapuserd.cpp
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2020 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 <linux/types.h>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/stringprintf.h>
+#include <android-base/unique_fd.h>
+#include <libdm/dm.h>
+
+using android::base::unique_fd;
+
+#define DM_USER_MAP_READ 0
+#define DM_USER_MAP_WRITE 1
+
+struct dm_user_message {
+ __u64 seq;
+ __u64 type;
+ __u64 flags;
+ __u64 sector;
+ __u64 len;
+ __u8 buf[];
+};
+
+using namespace android::dm;
+
+static int daemon_main(const std::string& device) {
+ unique_fd block_fd(open(device.c_str(), O_RDWR));
+ if (block_fd < 0) {
+ PLOG(ERROR) << "Unable to open " << device;
+ return 1;
+ }
+
+ unique_fd ctrl_fd(open("/dev/dm-user", O_RDWR));
+ if (ctrl_fd < 0) {
+ PLOG(ERROR) << "Unable to open /dev/dm-user";
+ return 1;
+ }
+
+ size_t buf_size = 1UL << 16;
+ auto buf = std::make_unique<char>(buf_size);
+
+ /* Just keeps pumping messages between userspace and the kernel. We won't
+ * actually be doing anything, but the sequence numbers line up so it'll at
+ * least make forward progress. */
+ while (true) {
+ struct dm_user_message* msg = (struct dm_user_message*)buf.get();
+
+ memset(buf.get(), 0, buf_size);
+
+ ssize_t readed = read(ctrl_fd.get(), buf.get(), buf_size);
+ if (readed < 0) {
+ PLOG(ERROR) << "Control read failed, trying with more space";
+ buf_size *= 2;
+ buf = std::make_unique<char>(buf_size);
+ continue;
+ }
+
+ LOG(DEBUG) << android::base::StringPrintf("read() from dm-user returned %d bytes:",
+ (int)readed);
+ LOG(DEBUG) << android::base::StringPrintf(" msg->seq: 0x%016llx", msg->seq);
+ LOG(DEBUG) << android::base::StringPrintf(" msg->type: 0x%016llx", msg->type);
+ LOG(DEBUG) << android::base::StringPrintf(" msg->flags: 0x%016llx", msg->flags);
+ LOG(DEBUG) << android::base::StringPrintf(" msg->sector: 0x%016llx", msg->sector);
+ LOG(DEBUG) << android::base::StringPrintf(" msg->len: 0x%016llx", msg->len);
+
+ switch (msg->type) {
+ case DM_USER_MAP_READ: {
+ LOG(DEBUG) << android::base::StringPrintf(
+ "Responding to read of sector %lld with %lld bytes data", msg->sector,
+ msg->len);
+
+ if ((sizeof(*msg) + msg->len) > buf_size) {
+ auto old_buf = std::move(buf);
+ buf_size = sizeof(*msg) + msg->len;
+ buf = std::make_unique<char>(buf_size);
+ memcpy(buf.get(), old_buf.get(), sizeof(*msg));
+ msg = (struct dm_user_message*)buf.get();
+ }
+
+ if (lseek(block_fd.get(), msg->sector * 512, SEEK_SET) < 0) {
+ PLOG(ERROR) << "lseek failed: " << device;
+ return 7;
+ }
+ if (!android::base::ReadFully(block_fd.get(), msg->buf, msg->len)) {
+ PLOG(ERROR) << "read failed: " << device;
+ return 7;
+ }
+
+ if (!android::base::WriteFully(ctrl_fd.get(), buf.get(), sizeof(*msg) + msg->len)) {
+ PLOG(ERROR) << "write control failed";
+ return 3;
+ }
+ break;
+ }
+
+ case DM_USER_MAP_WRITE:
+ abort();
+ break;
+ }
+
+ LOG(DEBUG) << "read() finished, next message";
+ }
+
+ return 0;
+}
+
+int main([[maybe_unused]] int argc, char** argv) {
+ android::base::InitLogging(argv, &android::base::KernelLogger);
+ daemon_main(argv[1]);
+ return 0;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-12-24 00:58:19 +0000