init: Wait for daemon to fully spin up all threads
During selinux transition, daemon will notify `init` process
by writing to file "/metadata/ota/daemon-alive-indicator".
Init will wait until daemon notifies it. Furthermore, daemon
will only write to that file once all threads are spin up
and attached to dm-user misc devices.
Once snapshot-merge is completed, this file will be removed.
Additionally, during boot, init will also ensure that
there are no stale files and will try to remove just
before selinux transition.
Bug: 262407519
Test: OTA on Pixel - Verify new file exits and init waits until daemon
is fully up.
Change-Id: Iabef58ad282d80a7afa493e9df9468ae41a13e44
Signed-off-by: Akilesh Kailash <akailash@google.com>
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index 6fed09c..e5e0e18 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -1498,6 +1498,7 @@
if (UpdateUsesUserSnapshots(lock) && !device()->IsTestDevice()) {
if (snapuserd_client_) {
snapuserd_client_->DetachSnapuserd();
+ snapuserd_client_->RemoveTransitionedDaemonIndicator();
snapuserd_client_ = nullptr;
}
}
diff --git a/fs_mgr/libsnapshot/snapuserd/Android.bp b/fs_mgr/libsnapshot/snapuserd/Android.bp
index 64e0b8a..a67e37c 100644
--- a/fs_mgr/libsnapshot/snapuserd/Android.bp
+++ b/fs_mgr/libsnapshot/snapuserd/Android.bp
@@ -37,11 +37,13 @@
cc_library_static {
name: "libsnapshot_snapuserd",
defaults: [
+ "fs_mgr_defaults",
"libsnapshot_snapuserd_defaults",
],
recovery_available: true,
static_libs: [
"libcutils_sockets",
+ "libfs_mgr",
],
shared_libs: [
"libbase",
@@ -49,6 +51,7 @@
],
export_include_dirs: ["include"],
ramdisk_available: true,
+ vendor_ramdisk_available: true,
}
cc_defaults {
@@ -86,6 +89,7 @@
"libgflags",
"liblog",
"libsnapshot_cow",
+ "libsnapshot_snapuserd",
"libz",
"liblz4",
"libext4_utils",
diff --git a/fs_mgr/libsnapshot/snapuserd/include/snapuserd/snapuserd_client.h b/fs_mgr/libsnapshot/snapuserd/include/snapuserd/snapuserd_client.h
index 4b62b20..fb2251e 100644
--- a/fs_mgr/libsnapshot/snapuserd/include/snapuserd/snapuserd_client.h
+++ b/fs_mgr/libsnapshot/snapuserd/include/snapuserd/snapuserd_client.h
@@ -32,6 +32,7 @@
static constexpr char kSnapuserdSocket[] = "snapuserd";
static constexpr char kSnapuserdSocketProxy[] = "snapuserd_proxy";
+static constexpr char kDaemonAliveIndicator[] = "daemon-alive-indicator";
// Ensure that the second-stage daemon for snapuserd is running.
bool EnsureSnapuserdStarted();
@@ -44,9 +45,11 @@
std::string Receivemsg();
bool ValidateConnection();
+ std::string GetDaemonAliveIndicatorPath();
public:
explicit SnapuserdClient(android::base::unique_fd&& sockfd);
+ SnapuserdClient(){};
static std::unique_ptr<SnapuserdClient> Connect(const std::string& socket_name,
std::chrono::milliseconds timeout_ms);
@@ -91,6 +94,17 @@
// Check the update verification status - invoked by update_verifier during
// boot
bool QueryUpdateVerification();
+
+ // Check if Snapuser daemon is ready post selinux transition after OTA boot
+ // This is invoked only by init as there is no sockets setup yet during
+ // selinux transition
+ bool IsTransitionedDaemonReady();
+
+ // Remove the daemon-alive-indicator path post snapshot merge
+ bool RemoveTransitionedDaemonIndicator();
+
+ // Notify init that snapuserd daemon is ready post selinux transition
+ void NotifyTransitionDaemonIsReady();
};
} // namespace snapshot
diff --git a/fs_mgr/libsnapshot/snapuserd/snapuserd_client.cpp b/fs_mgr/libsnapshot/snapuserd/snapuserd_client.cpp
index e08cf9b..695b581 100644
--- a/fs_mgr/libsnapshot/snapuserd/snapuserd_client.cpp
+++ b/fs_mgr/libsnapshot/snapuserd/snapuserd_client.cpp
@@ -29,10 +29,12 @@
#include <chrono>
#include <sstream>
+#include <android-base/file.h>
#include <android-base/logging.h>
#include <android-base/parseint.h>
#include <android-base/properties.h>
#include <android-base/strings.h>
+#include <fs_mgr/file_wait.h>
#include <snapuserd/snapuserd_client.h>
namespace android {
@@ -279,5 +281,42 @@
return response == "success";
}
+std::string SnapuserdClient::GetDaemonAliveIndicatorPath() {
+ return "/metadata/ota/" + std::string(kDaemonAliveIndicator);
+}
+
+bool SnapuserdClient::IsTransitionedDaemonReady() {
+ if (!android::fs_mgr::WaitForFile(GetDaemonAliveIndicatorPath(), 10s)) {
+ LOG(ERROR) << "Timed out waiting for daemon indicator path: "
+ << GetDaemonAliveIndicatorPath();
+ return false;
+ }
+
+ return true;
+}
+
+bool SnapuserdClient::RemoveTransitionedDaemonIndicator() {
+ std::string error;
+ std::string filePath = GetDaemonAliveIndicatorPath();
+ if (!android::base::RemoveFileIfExists(filePath, &error)) {
+ LOG(ERROR) << "Failed to remove DaemonAliveIndicatorPath - error: " << error;
+ return false;
+ }
+
+ if (!android::fs_mgr::WaitForFileDeleted(filePath, 5s)) {
+ LOG(ERROR) << "Timed out waiting for " << filePath << " to unlink";
+ return false;
+ }
+
+ return true;
+}
+
+void SnapuserdClient::NotifyTransitionDaemonIsReady() {
+ if (!android::base::WriteStringToFile("1", GetDaemonAliveIndicatorPath())) {
+ PLOG(ERROR) << "Unable to write daemon alive indicator path: "
+ << GetDaemonAliveIndicatorPath();
+ }
+}
+
} // namespace snapshot
} // namespace android
diff --git a/fs_mgr/libsnapshot/snapuserd/snapuserd_daemon.cpp b/fs_mgr/libsnapshot/snapuserd/snapuserd_daemon.cpp
index 2f7775c..bfe93eb 100644
--- a/fs_mgr/libsnapshot/snapuserd/snapuserd_daemon.cpp
+++ b/fs_mgr/libsnapshot/snapuserd/snapuserd_daemon.cpp
@@ -119,6 +119,12 @@
}
}
+ // We reach this point only during selinux transition during device boot.
+ // At this point, all threads are spin up and are ready to serve the I/O
+ // requests for dm-user. Lets inform init.
+ auto client = std::make_unique<SnapuserdClient>();
+ client->NotifyTransitionDaemonIsReady();
+
// Skip the accept() call to avoid spurious log spam. The server will still
// run until all handlers have completed.
return user_server_.WaitForSocket();
diff --git a/init/snapuserd_transition.cpp b/init/snapuserd_transition.cpp
index 6972f30..3a9ff5b 100644
--- a/init/snapuserd_transition.cpp
+++ b/init/snapuserd_transition.cpp
@@ -112,6 +112,10 @@
setenv(kSnapuserdFirstStagePidVar, std::to_string(pid).c_str(), 1);
+ if (!client->RemoveTransitionedDaemonIndicator()) {
+ LOG(ERROR) << "RemoveTransitionedDaemonIndicator failed";
+ }
+
LOG(INFO) << "Relaunched snapuserd with pid: " << pid;
}
@@ -263,6 +267,19 @@
* we may see audit logs.
*/
bool SnapuserdSelinuxHelper::TestSnapuserdIsReady() {
+ // Wait for the daemon to be fully up. Daemon will write to path
+ // /metadata/ota/daemon-alive-indicator only when all the threads
+ // are ready and attached to dm-user.
+ //
+ // This check will fail for GRF devices with vendor on Android S.
+ // snapuserd binary from Android S won't be able to communicate
+ // and hence, we will fallback and issue I/O to verify
+ // the presence of daemon.
+ auto client = std::make_unique<SnapuserdClient>();
+ if (!client->IsTransitionedDaemonReady()) {
+ LOG(ERROR) << "IsTransitionedDaemonReady failed";
+ }
+
std::string dev = "/dev/block/mapper/system"s + fs_mgr_get_slot_suffix();
android::base::unique_fd fd(open(dev.c_str(), O_RDONLY | O_DIRECT));
if (fd < 0) {