RESTRICT AUTOMERGE: snapuserd: Run snapuserd threads in-process.

This removes the temporary daemon and socket and instead directly embeds
SnapshotHandlerManager. We can also remove the test flags for io_uring
as with this they're no longer necessary.

Bug: 269361087
Test: snapuserd_test
Change-Id: I728186d9bc90c98fabd76d3f86569840488ada96
diff --git a/fs_mgr/libsnapshot/snapuserd/Android.bp b/fs_mgr/libsnapshot/snapuserd/Android.bp
index 7fcaac5..1e03683 100644
--- a/fs_mgr/libsnapshot/snapuserd/Android.bp
+++ b/fs_mgr/libsnapshot/snapuserd/Android.bp
@@ -164,7 +164,7 @@
 }
 
 cc_test {
-    name: "cow_snapuserd_test",
+    name: "snapuserd_test_legacy",
     defaults: [
         "fs_mgr_defaults",
         "libsnapshot_cow_defaults",
@@ -216,16 +216,17 @@
     ],
     static_libs: [
         "libbrotli",
+        "libcutils_sockets",
+        "libdm",
+        "libext4_utils",
+        "libfs_mgr",
+        "libgflags",
         "libgtest",
         "libsnapshot_cow",
         "libsnapshot_snapuserd",
-        "libcutils_sockets",
-        "libz",
-        "libfs_mgr",
-        "libdm",
-        "libext4_utils",
+        "libsnapuserd",
         "liburing",
-        "libgflags",
+        "libz",
     ],
     include_dirs: ["bionic/libc/kernel"],
     header_libs: [
diff --git a/fs_mgr/libsnapshot/snapuserd/user-space-merge/handler_manager.cpp b/fs_mgr/libsnapshot/snapuserd/user-space-merge/handler_manager.cpp
index c5150c4..bdba5c0 100644
--- a/fs_mgr/libsnapshot/snapuserd/user-space-merge/handler_manager.cpp
+++ b/fs_mgr/libsnapshot/snapuserd/user-space-merge/handler_manager.cpp
@@ -25,6 +25,9 @@
 
 static constexpr uint8_t kMaxMergeThreads = 2;
 
+HandlerThread::HandlerThread(std::shared_ptr<SnapshotHandler> snapuserd)
+    : snapuserd_(snapuserd), misc_name_(snapuserd_->GetMiscName()) {}
+
 void HandlerThread::FreeResources() {
     // Each worker thread holds a reference to snapuserd.
     // Clear them so that all the resources
diff --git a/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_core.cpp b/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_core.cpp
index 2c201ff..25ce0ae 100644
--- a/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_core.cpp
+++ b/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_core.cpp
@@ -433,11 +433,6 @@
     struct utsname uts;
     unsigned int major, minor;
 
-    if (android::base::GetBoolProperty("snapuserd.test.io_uring.force_disable", false)) {
-        SNAP_LOG(INFO) << "io_uring disabled for testing";
-        return false;
-    }
-
     if ((uname(&uts) != 0) || (sscanf(uts.release, "%u.%u", &major, &minor) != 2)) {
         SNAP_LOG(ERROR) << "Could not parse the kernel version from uname. "
                         << " io_uring not supported";
diff --git a/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_server.cpp b/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_server.cpp
index d87990a..c953f1a 100644
--- a/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_server.cpp
+++ b/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_server.cpp
@@ -83,9 +83,6 @@
     handlers_->JoinAllThreads();
 }
 
-HandlerThread::HandlerThread(std::shared_ptr<SnapshotHandler> snapuserd)
-    : snapuserd_(snapuserd), misc_name_(snapuserd_->GetMiscName()) {}
-
 bool UserSnapshotServer::Sendmsg(android::base::borrowed_fd fd, const std::string& msg) {
     ssize_t ret = TEMP_FAILURE_RETRY(send(fd.get(), msg.data(), msg.size(), MSG_NOSIGNAL));
     if (ret < 0) {
diff --git a/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_test.cpp b/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_test.cpp
index 1421403..57f9e7a 100644
--- a/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_test.cpp
+++ b/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_test.cpp
@@ -37,9 +37,9 @@
 #include <libdm/dm.h>
 #include <libdm/loop_control.h>
 #include <libsnapshot/cow_writer.h>
-#include <snapuserd/snapuserd_client.h>
 #include <storage_literals/storage_literals.h>
 
+#include "handler_manager.h"
 #include "snapuserd_core.h"
 
 DEFINE_string(force_config, "", "Force testing mode with iouring disabled");
@@ -54,8 +54,6 @@
 using namespace android::dm;
 using namespace std;
 
-static constexpr char kSnapuserdSocketTest[] = "snapuserdTest";
-
 class Tempdevice {
   public:
     Tempdevice(const std::string& name, const DmTable& table)
@@ -68,15 +66,15 @@
     }
     ~Tempdevice() {
         if (valid_) {
-            dm_.DeleteDevice(name_);
+            dm_.DeleteDeviceIfExists(name_);
         }
     }
     bool Destroy() {
         if (!valid_) {
-            return false;
+            return true;
         }
         valid_ = false;
-        return dm_.DeleteDevice(name_);
+        return dm_.DeleteDeviceIfExists(name_);
     }
     const std::string& path() const { return path_; }
     const std::string& name() const { return name_; }
@@ -138,7 +136,6 @@
     void SetDeviceControlName();
     void InitDaemon();
     void CreateDmUserDevice();
-    void StartSnapuserdDaemon();
 
     unique_ptr<LoopDevice> base_loop_;
     unique_ptr<Tempdevice> dmuser_dev_;
@@ -148,9 +145,9 @@
 
     unique_fd base_fd_;
     std::unique_ptr<TemporaryFile> cow_system_;
-    std::unique_ptr<SnapuserdClient> client_;
     std::unique_ptr<uint8_t[]> orig_buffer_;
     std::unique_ptr<uint8_t[]> merged_buffer_;
+    SnapshotHandlerManager handlers_;
     bool setup_ok_ = false;
     bool merge_ok_ = false;
     size_t size_ = 100_MiB;
@@ -180,9 +177,9 @@
     ASSERT_TRUE(dmuser_dev_->Destroy());
 
     auto misc_device = "/dev/dm-user/" + system_device_ctrl_name_;
-    ASSERT_TRUE(client_->WaitForDeviceDelete(system_device_ctrl_name_));
+    ASSERT_TRUE(handlers_.DeleteHandler(system_device_ctrl_name_));
     ASSERT_TRUE(android::fs_mgr::WaitForFileDeleted(misc_device, 10s));
-    ASSERT_TRUE(client_->DetachSnapuserd());
+    handlers_.TerminateMergeThreads();
 }
 
 bool SnapuserdTest::SetupDefault() {
@@ -217,8 +214,6 @@
 bool SnapuserdTest::SetupDaemon() {
     SetDeviceControlName();
 
-    StartSnapuserdDaemon();
-
     CreateDmUserDevice();
     InitCowDevice();
     InitDaemon();
@@ -228,20 +223,6 @@
     return setup_ok_;
 }
 
-void SnapuserdTest::StartSnapuserdDaemon() {
-    pid_t pid = fork();
-    ASSERT_GE(pid, 0);
-    if (pid == 0) {
-        std::string arg0 = "/system/bin/snapuserd";
-        std::string arg1 = "-socket="s + kSnapuserdSocketTest;
-        char* const argv[] = {arg0.data(), arg1.data(), nullptr};
-        ASSERT_GE(execv(arg0.c_str(), argv), 0);
-    } else {
-        client_ = SnapuserdClient::Connect(kSnapuserdSocketTest, 10s);
-        ASSERT_NE(client_, nullptr);
-    }
-}
-
 void SnapuserdTest::CreateBaseDevice() {
     unique_fd rnd_fd;
 
@@ -606,9 +587,17 @@
 }
 
 void SnapuserdTest::InitCowDevice() {
-    uint64_t num_sectors = client_->InitDmUserCow(system_device_ctrl_name_, cow_system_->path,
-                                                  base_loop_->device(), base_loop_->device());
-    ASSERT_NE(num_sectors, 0);
+    bool use_iouring = true;
+    if (FLAGS_force_config == "iouring_disabled") {
+        use_iouring = false;
+    }
+
+    auto handler =
+            handlers_.AddHandler(system_device_ctrl_name_, cow_system_->path, base_loop_->device(),
+                                 base_loop_->device(), 1, use_iouring, false);
+    ASSERT_NE(handler, nullptr);
+    ASSERT_NE(handler->snapuserd(), nullptr);
+    ASSERT_NE(handler->snapuserd()->GetNumSectors(), 0);
 }
 
 void SnapuserdTest::SetDeviceControlName() {
@@ -646,13 +635,12 @@
 }
 
 void SnapuserdTest::InitDaemon() {
-    bool ok = client_->AttachDmUser(system_device_ctrl_name_);
-    ASSERT_TRUE(ok);
+    ASSERT_TRUE(handlers_.StartHandler(system_device_ctrl_name_));
 }
 
 void SnapuserdTest::CheckMergeCompletion() {
     while (true) {
-        double percentage = client_->GetMergePercent();
+        double percentage = handlers_.GetMergePercentage();
         if ((int)percentage == 100) {
             break;
         }
@@ -667,8 +655,6 @@
 
     SetDeviceControlName();
 
-    StartSnapuserdDaemon();
-
     CreateDmUserDevice();
     InitCowDevice();
     InitDaemon();
@@ -684,8 +670,7 @@
 }
 
 void SnapuserdTest::StartMerge() {
-    bool ok = client_->InitiateMerge(system_device_ctrl_name_);
-    ASSERT_TRUE(ok);
+    ASSERT_TRUE(handlers_.InitiateMerge(system_device_ctrl_name_));
 }
 
 void SnapuserdTest::ValidateMerge() {
@@ -699,7 +684,6 @@
     Shutdown();
     std::this_thread::sleep_for(500ms);
     SetDeviceControlName();
-    StartSnapuserdDaemon();
     CreateDmUserDevice();
     InitCowDevice();
     InitDaemon();
@@ -859,20 +843,5 @@
 
     gflags::ParseCommandLineFlags(&argc, &argv, false);
 
-    android::base::SetProperty("ctl.stop", "snapuserd");
-
-    if (FLAGS_force_config == "iouring_disabled") {
-        if (!android::base::SetProperty("snapuserd.test.io_uring.force_disable", "1")) {
-            return testing::AssertionFailure()
-                   << "Failed to disable property: snapuserd.test.io_uring.disabled";
-        }
-    }
-
-    int ret = RUN_ALL_TESTS();
-
-    if (FLAGS_force_config == "iouring_disabled") {
-        android::base::SetProperty("snapuserd.test.io_uring.force_disable", "0");
-    }
-
-    return ret;
+    return RUN_ALL_TESTS();
 }