libsnapshot: Propagate io_uring enablement to daemon

During selinux init transition, system properties
are not yet enabled. Hence, store the io_uring feature
in snapshot.proto and propagate the same snapuserd
daemon

Bug: 214340811
Test: OTA
Signed-off-by: Akilesh Kailash <akailash@google.com>
Change-Id: I5458127b00946b5254d5c68d407ab525a0075cb9
diff --git a/fs_mgr/libsnapshot/android/snapshot/snapshot.proto b/fs_mgr/libsnapshot/android/snapshot/snapshot.proto
index 532f66d..5daa84d 100644
--- a/fs_mgr/libsnapshot/android/snapshot/snapshot.proto
+++ b/fs_mgr/libsnapshot/android/snapshot/snapshot.proto
@@ -197,6 +197,9 @@
 
     // user-space snapshots
     bool userspace_snapshots = 9;
+
+    // io_uring support
+    bool io_uring_enabled = 10;
 }
 
 // Next: 10
diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
index 120f95b..38b47d5 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
@@ -809,6 +809,9 @@
     // userspace snapshots.
     bool UpdateUsesUserSnapshots(LockedFile* lock);
 
+    // Check if io_uring API's need to be used
+    bool UpdateUsesIouring(LockedFile* lock);
+
     // Wrapper around libdm, with diagnostics.
     bool DeleteDeviceIfExists(const std::string& name,
                               const std::chrono::milliseconds& timeout_ms = {});
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index f3de2b4..797d627 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -1685,6 +1685,9 @@
 
     if (UpdateUsesUserSnapshots(lock.get()) && transition == InitTransition::SELINUX_DETACH) {
         snapuserd_argv->emplace_back("-user_snapshot");
+        if (UpdateUsesIouring(lock.get())) {
+            snapuserd_argv->emplace_back("-io_uring");
+        }
     }
 
     size_t num_cows = 0;
@@ -2062,6 +2065,11 @@
     return update_status.compression_enabled();
 }
 
+bool SnapshotManager::UpdateUsesIouring(LockedFile* lock) {
+    SnapshotUpdateStatus update_status = ReadSnapshotUpdateStatus(lock);
+    return update_status.io_uring_enabled();
+}
+
 bool SnapshotManager::UpdateUsesUserSnapshots() {
     // This and the following function is constantly
     // invoked during snapshot merge. We want to avoid
@@ -2877,6 +2885,7 @@
         status.set_source_build_fingerprint(old_status.source_build_fingerprint());
         status.set_merge_phase(old_status.merge_phase());
         status.set_userspace_snapshots(old_status.userspace_snapshots());
+        status.set_io_uring_enabled(old_status.io_uring_enabled());
     }
     return WriteSnapshotUpdateStatus(lock, status);
 }
@@ -3200,6 +3209,7 @@
             status.set_userspace_snapshots(IsUserspaceSnapshotsEnabled());
             if (IsUserspaceSnapshotsEnabled()) {
                 is_snapshot_userspace_ = true;
+                status.set_io_uring_enabled(IsIouringEnabled());
                 LOG(INFO) << "User-space snapshots enabled";
             } else {
                 is_snapshot_userspace_ = false;
diff --git a/fs_mgr/libsnapshot/snapuserd/snapuserd_daemon.cpp b/fs_mgr/libsnapshot/snapuserd/snapuserd_daemon.cpp
index 36bf0e4..0b88567 100644
--- a/fs_mgr/libsnapshot/snapuserd/snapuserd_daemon.cpp
+++ b/fs_mgr/libsnapshot/snapuserd/snapuserd_daemon.cpp
@@ -28,6 +28,7 @@
 DEFINE_bool(socket_handoff, false,
             "If true, perform a socket hand-off with an existing snapuserd instance, then exit.");
 DEFINE_bool(user_snapshot, false, "If true, user-space snapshots are used");
+DEFINE_bool(io_uring, false, "If true, io_uring feature is enabled");
 
 namespace android {
 namespace snapshot {
@@ -81,6 +82,9 @@
     MaskAllSignalsExceptIntAndTerm();
 
     user_server_.SetServerRunning();
+    if (FLAGS_io_uring) {
+        user_server_.SetIouringEnabled();
+    }
 
     if (FLAGS_socket_handoff) {
         return user_server_.RunForSocketHandoff();
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 f1e2f3e..9dd52b4 100644
--- a/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_core.cpp
+++ b/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_core.cpp
@@ -691,6 +691,14 @@
         return false;
     }
 
+    // During selinux init transition, libsnapshot will propagate the
+    // status of io_uring enablement. As properties are not initialized,
+    // we cannot query system property.
+    if (is_io_uring_enabled_) {
+        return true;
+    }
+
+    // Finally check the system property
     return android::base::GetBoolProperty("ro.virtual_ab.io_uring.enabled", false);
 }
 
diff --git a/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_core.h b/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_core.h
index b0f2d65..cc82985 100644
--- a/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_core.h
+++ b/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_core.h
@@ -319,6 +319,7 @@
     void SetMergedBlockCountForNextCommit(int x) { total_ra_blocks_merged_ = x; }
     int GetTotalBlocksToMerge() { return total_ra_blocks_merged_; }
     void SetSocketPresent(bool socket) { is_socket_present_ = socket; }
+    void SetIouringEnabled(bool io_uring_enabled) { is_io_uring_enabled_ = io_uring_enabled; }
     bool MergeInitiated() { return merge_initiated_; }
     double GetMergePercentage() { return merge_completion_percentage_; }
 
@@ -396,6 +397,7 @@
     bool merge_initiated_ = false;
     bool attached_ = false;
     bool is_socket_present_;
+    bool is_io_uring_enabled_ = false;
     bool scratch_space_ = false;
 
     std::unique_ptr<struct io_uring> ring_;
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 1d2835a..82b2b25 100644
--- a/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_server.cpp
+++ b/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_server.cpp
@@ -471,6 +471,7 @@
     }
 
     snapuserd->SetSocketPresent(is_socket_present_);
+    snapuserd->SetIouringEnabled(io_uring_enabled_);
 
     if (!snapuserd->InitializeWorkers()) {
         LOG(ERROR) << "Failed to initialize workers";
diff --git a/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_server.h b/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_server.h
index e38f618..34e7941 100644
--- a/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_server.h
+++ b/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_server.h
@@ -85,6 +85,7 @@
     bool is_socket_present_ = false;
     int num_partitions_merge_complete_ = 0;
     bool is_server_running_ = false;
+    bool io_uring_enabled_ = false;
 
     std::mutex lock_;
 
@@ -139,6 +140,8 @@
     void ReceivedSocketSignal() { received_socket_signal_ = true; }
     void SetServerRunning() { is_server_running_ = true; }
     bool IsServerRunning() { return is_server_running_; }
+    void SetIouringEnabled() { io_uring_enabled_ = true; }
+    bool IsIouringEnabled() { return io_uring_enabled_; }
 };
 
 }  // namespace snapshot
diff --git a/fs_mgr/libsnapshot/utility.cpp b/fs_mgr/libsnapshot/utility.cpp
index 89d6145..f01bec9 100644
--- a/fs_mgr/libsnapshot/utility.cpp
+++ b/fs_mgr/libsnapshot/utility.cpp
@@ -192,6 +192,10 @@
     return android::base::GetBoolProperty("ro.virtual_ab.userspace.snapshots.enabled", false);
 }
 
+bool IsIouringEnabled() {
+    return android::base::GetBoolProperty("ro.virtual_ab.io_uring.enabled", false);
+}
+
 std::string GetOtherPartitionName(const std::string& name) {
     auto suffix = android::fs_mgr::GetPartitionSlotSuffix(name);
     CHECK(suffix == "_a" || suffix == "_b");
diff --git a/fs_mgr/libsnapshot/utility.h b/fs_mgr/libsnapshot/utility.h
index a032b68..0ef3234 100644
--- a/fs_mgr/libsnapshot/utility.h
+++ b/fs_mgr/libsnapshot/utility.h
@@ -135,6 +135,8 @@
 
 bool IsDmSnapshotTestingEnabled();
 
+bool IsIouringEnabled();
+
 // Swap the suffix of a partition name.
 std::string GetOtherPartitionName(const std::string& name);
 }  // namespace snapshot