Merge "init: poll in first stage mount if required devices are not found"

am: 20e9312344

Change-Id: I3055e999ff976662da18818756fc6ed07b09f360

init/init_first_stage.cpp

@@ -19,6 +19,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+#include <chrono>
 #include <memory>
 #include <set>
 #include <string>
@@ -35,6 +36,8 @@
 #include "uevent_listener.h"
 #include "util.h"
 
+using namespace std::chrono_literals;
+
 // Class Declarations
 // ------------------
 class FirstStageMount {
@@ -49,11 +52,11 @@ class FirstStageMount {
     bool InitDevices();
 
   protected:
-    void InitRequiredDevices();
+    bool InitRequiredDevices();
-    void InitVerityDevice(const std::string& verity_device);
+    bool InitVerityDevice(const std::string& verity_device);
     bool MountPartitions();
 
-    virtual RegenerationAction UeventCallback(const Uevent& uevent);
+    virtual ListenerAction UeventCallback(const Uevent& uevent);
 
     // Pure virtual functions.
     virtual bool GetRequiredDevices() = 0;
@@ -86,7 +89,7 @@ class FirstStageMountVBootV2 : public FirstStageMount {
     ~FirstStageMountVBootV2() override = default;
 
   protected:
-    RegenerationAction UeventCallback(const Uevent& uevent) override;
+    ListenerAction UeventCallback(const Uevent& uevent) override;
     bool GetRequiredDevices() override;
     bool SetUpDmVerity(fstab_rec* fstab_rec) override;
     bool InitAvbHandle();
@@ -141,49 +144,60 @@ bool FirstStageMount::DoFirstStageMount() {
 }
 
 bool FirstStageMount::InitDevices() {
-    if (!GetRequiredDevices()) return false;
+    return GetRequiredDevices() && InitRequiredDevices();
-
-    InitRequiredDevices();
-
-    // InitRequiredDevices() will remove found partitions from required_devices_partition_names_.
-    // So if it isn't empty here, it means some partitions are not found.
-    if (!required_devices_partition_names_.empty()) {
-        LOG(ERROR) << __FUNCTION__ << "(): partition(s) not found: "
-                   << android::base::Join(required_devices_partition_names_, ", ");
-        return false;
-    } else {
-        return true;
-    }
 }
 
 // Creates devices with uevent->partition_name matching one in the member variable
 // required_devices_partition_names_. Found partitions will then be removed from it
 // for the subsequent member function to check which devices are NOT created.
-void FirstStageMount::InitRequiredDevices() {
+bool FirstStageMount::InitRequiredDevices() {
     if (required_devices_partition_names_.empty()) {
-        return;
+        return true;
     }
 
     if (need_dm_verity_) {
         const std::string dm_path = "/devices/virtual/misc/device-mapper";
-        uevent_listener_.RegenerateUeventsForPath("/sys" + dm_path,
+        bool found = false;
-                                                  [this, &dm_path](const Uevent& uevent) {
+        auto dm_callback = [this, &dm_path, &found](const Uevent& uevent) {
-                                                      if (uevent.path == dm_path) {
+            if (uevent.path == dm_path) {
-                                                          device_handler_.HandleDeviceEvent(uevent);
+                device_handler_.HandleDeviceEvent(uevent);
-                                                          return RegenerationAction::kStop;
+                found = true;
-                                                      }
+                return ListenerAction::kStop;
-                                                      return RegenerationAction::kContinue;
+            }
-                                                  });
+            return ListenerAction::kContinue;
+        };
+        uevent_listener_.RegenerateUeventsForPath("/sys" + dm_path, dm_callback);
+        if (!found) {
+            uevent_listener_.Poll(dm_callback, 10s);
+        }
+        if (!found) {
+            LOG(ERROR) << "device-mapper device not found";
+            return false;
+        }
     }
 
-    uevent_listener_.RegenerateUevents(
+    auto uevent_callback = [this](const Uevent& uevent) { return UeventCallback(uevent); };
-        [this](const Uevent& uevent) { return UeventCallback(uevent); });
+    uevent_listener_.RegenerateUevents(uevent_callback);
+
+    // UeventCallback() will remove found partitions from required_devices_partition_names_.
+    // So if it isn't empty here, it means some partitions are not found.
+    if (!required_devices_partition_names_.empty()) {
+        uevent_listener_.Poll(uevent_callback, 10s);
+    }
+
+    if (!required_devices_partition_names_.empty()) {
+        LOG(ERROR) << __PRETTY_FUNCTION__ << ": partition(s) not found: "
+                   << android::base::Join(required_devices_partition_names_, ", ");
+        return false;
+    }
+
+    return true;
 }
 
-RegenerationAction FirstStageMount::UeventCallback(const Uevent& uevent) {
+ListenerAction FirstStageMount::UeventCallback(const Uevent& uevent) {
     // Ignores everything that is not a block device.
     if (uevent.subsystem != "block") {
-        return RegenerationAction::kContinue;
+        return ListenerAction::kContinue;
     }
 
     if (!uevent.partition_name.empty()) {
@@ -192,34 +206,46 @@ RegenerationAction FirstStageMount::UeventCallback(const Uevent& uevent) {
         // suffix when A/B is used.
         auto iter = required_devices_partition_names_.find(uevent.partition_name);
         if (iter != required_devices_partition_names_.end()) {
-            LOG(VERBOSE) << __FUNCTION__ << "(): found partition: " << *iter;
+            LOG(VERBOSE) << __PRETTY_FUNCTION__ << ": found partition: " << *iter;
             required_devices_partition_names_.erase(iter);
             device_handler_.HandleDeviceEvent(uevent);
             if (required_devices_partition_names_.empty()) {
-                return RegenerationAction::kStop;
+                return ListenerAction::kStop;
             } else {
-                return RegenerationAction::kContinue;
+                return ListenerAction::kContinue;
             }
         }
     }
     // Not found a partition or find an unneeded partition, continue to find others.
-    return RegenerationAction::kContinue;
+    return ListenerAction::kContinue;
 }
 
 // Creates "/dev/block/dm-XX" for dm-verity by running coldboot on /sys/block/dm-XX.
-void FirstStageMount::InitVerityDevice(const std::string& verity_device) {
+bool FirstStageMount::InitVerityDevice(const std::string& verity_device) {
     const std::string device_name(basename(verity_device.c_str()));
     const std::string syspath = "/sys/block/" + device_name;
+    bool found = false;
 
-    uevent_listener_.RegenerateUeventsForPath(
+    auto verity_callback = [&device_name, &verity_device, this, &found](const Uevent& uevent) {
-        syspath, [&device_name, &verity_device, this](const Uevent& uevent) {
+        if (uevent.device_name == device_name) {
-            if (uevent.device_name == device_name) {
+            LOG(VERBOSE) << "Creating dm-verity device : " << verity_device;
-                LOG(VERBOSE) << "Creating dm-verity device : " << verity_device;
+            device_handler_.HandleDeviceEvent(uevent);
-                device_handler_.HandleDeviceEvent(uevent);
+            found = true;
-                return RegenerationAction::kStop;
+            return ListenerAction::kStop;
-            }
+        }
-            return RegenerationAction::kContinue;
+        return ListenerAction::kContinue;
-        });
+    };
+
+    uevent_listener_.RegenerateUeventsForPath(syspath, verity_callback);
+    if (!found) {
+        uevent_listener_.Poll(verity_callback, 10s);
+    }
+    if (!found) {
+        LOG(ERROR) << "dm-verity device not found";
+        return false;
+    }
+
+    return true;
 }
 
 bool FirstStageMount::MountPartitions() {
@@ -285,7 +311,7 @@ bool FirstStageMountVBootV1::SetUpDmVerity(fstab_rec* fstab_rec) {
         } else if (ret == FS_MGR_SETUP_VERITY_SUCCESS) {
             // The exact block device name (fstab_rec->blk_device) is changed to "/dev/block/dm-XX".
             // Needs to create it because ueventd isn't started in init first stage.
-            InitVerityDevice(fstab_rec->blk_device);
+            return InitVerityDevice(fstab_rec->blk_device);
         } else {
             return false;
         }
@@ -345,7 +371,7 @@ bool FirstStageMountVBootV2::GetRequiredDevices() {
     return true;
 }
 
-RegenerationAction FirstStageMountVBootV2::UeventCallback(const Uevent& uevent) {
+ListenerAction FirstStageMountVBootV2::UeventCallback(const Uevent& uevent) {
     // Check if this uevent corresponds to one of the required partitions and store its symlinks if
     // so, in order to create FsManagerAvbHandle later.
     // Note that the parent callback removes partitions from the list of required partitions

init/uevent_listener.cpp

@@ -121,8 +121,8 @@ bool UeventListener::ReadUevent(Uevent* uevent) const {
 // make sure we don't overrun the socket's buffer.
 //
 
-RegenerationAction UeventListener::RegenerateUeventsForDir(DIR* d,
+ListenerAction UeventListener::RegenerateUeventsForDir(DIR* d,
-                                                           RegenerateCallback callback) const {
+                                                       const ListenerCallback& callback) const {
     int dfd = dirfd(d);
 
     int fd = openat(dfd, "uevent", O_WRONLY);
@@ -132,7 +132,7 @@ RegenerationAction UeventListener::RegenerateUeventsForDir(DIR* d,
 
         Uevent uevent;
         while (ReadUevent(&uevent)) {
-            if (callback(uevent) == RegenerationAction::kStop) return RegenerationAction::kStop;
+            if (callback(uevent) == ListenerAction::kStop) return ListenerAction::kStop;
         }
     }
 
@@ -147,49 +147,67 @@ RegenerationAction UeventListener::RegenerateUeventsForDir(DIR* d,
         if (d2 == 0) {
             close(fd);
         } else {
-            if (RegenerateUeventsForDir(d2.get(), callback) == RegenerationAction::kStop) {
+            if (RegenerateUeventsForDir(d2.get(), callback) == ListenerAction::kStop) {
-                return RegenerationAction::kStop;
+                return ListenerAction::kStop;
             }
         }
     }
 
     // default is always to continue looking for uevents
-    return RegenerationAction::kContinue;
+    return ListenerAction::kContinue;
 }
 
-RegenerationAction UeventListener::RegenerateUeventsForPath(const std::string& path,
+ListenerAction UeventListener::RegenerateUeventsForPath(const std::string& path,
-                                                            RegenerateCallback callback) const {
+                                                        const ListenerCallback& callback) const {
     std::unique_ptr<DIR, decltype(&closedir)> d(opendir(path.c_str()), closedir);
-    if (!d) return RegenerationAction::kContinue;
+    if (!d) return ListenerAction::kContinue;
 
     return RegenerateUeventsForDir(d.get(), callback);
 }
 
 static const char* kRegenerationPaths[] = {"/sys/class", "/sys/block", "/sys/devices"};
 
-void UeventListener::RegenerateUevents(RegenerateCallback callback) const {
+void UeventListener::RegenerateUevents(const ListenerCallback& callback) const {
     for (const auto path : kRegenerationPaths) {
-        if (RegenerateUeventsForPath(path, callback) == RegenerationAction::kStop) return;
+        if (RegenerateUeventsForPath(path, callback) == ListenerAction::kStop) return;
     }
 }
 
-void UeventListener::DoPolling(PollCallback callback) const {
+void UeventListener::Poll(const ListenerCallback& callback,
+                          const std::optional<std::chrono::milliseconds> relative_timeout) const {
+    using namespace std::chrono;
+
     pollfd ufd;
     ufd.events = POLLIN;
     ufd.fd = device_fd_;
 
+    auto start_time = steady_clock::now();
+
     while (true) {
         ufd.revents = 0;
-        int nr = poll(&ufd, 1, -1);
+
-        if (nr <= 0) {
+        int timeout_ms = -1;
+        if (relative_timeout) {
+            auto now = steady_clock::now();
+            auto time_elapsed = duration_cast<milliseconds>(now - start_time);
+            if (time_elapsed > *relative_timeout) return;
+
+            auto remaining_timeout = *relative_timeout - time_elapsed;
+            timeout_ms = remaining_timeout.count();
+        }
+
+        int nr = poll(&ufd, 1, timeout_ms);
+        if (nr == 0) return;
+        if (nr < 0) {
+            PLOG(ERROR) << "poll() of uevent socket failed, continuing";
             continue;
         }
         if (ufd.revents & POLLIN) {
-            // We're non-blocking, so if we receive a poll event keep processing until there
+            // We're non-blocking, so if we receive a poll event keep processing until
             // we have exhausted all uevent messages.
             Uevent uevent;
             while (ReadUevent(&uevent)) {
-                callback(uevent);
+                if (callback(uevent) == ListenerAction::kStop) return;
             }
         }
     }

init/uevent_listener.h

@@ -19,7 +19,9 @@
 
 #include <dirent.h>
 
+#include <chrono>
 #include <functional>
+#include <optional>
 
 #include <android-base/unique_fd.h>
 
@@ -27,26 +29,26 @@
 
 #define UEVENT_MSG_LEN 2048
 
-enum class RegenerationAction {
+enum class ListenerAction {
     kStop = 0,  // Stop regenerating uevents as we've handled the one(s) we're interested in.
     kContinue,  // Continue regenerating uevents as we haven't seen the one(s) we're interested in.
 };
 
-using RegenerateCallback = std::function<RegenerationAction(const Uevent&)>;
+using ListenerCallback = std::function<ListenerAction(const Uevent&)>;
-using PollCallback = std::function<void(const Uevent&)>;
 
 class UeventListener {
   public:
     UeventListener();
 
-    void RegenerateUevents(RegenerateCallback callback) const;
+    void RegenerateUevents(const ListenerCallback& callback) const;
-    RegenerationAction RegenerateUeventsForPath(const std::string& path,
+    ListenerAction RegenerateUeventsForPath(const std::string& path,
-                                                RegenerateCallback callback) const;
+                                            const ListenerCallback& callback) const;
-    void DoPolling(PollCallback callback) const;
+    void Poll(const ListenerCallback& callback,
+              const std::optional<std::chrono::milliseconds> relative_timeout = {}) const;
 
   private:
     bool ReadUevent(Uevent* uevent) const;
-    RegenerationAction RegenerateUeventsForDir(DIR* d, RegenerateCallback callback) const;
+    ListenerAction RegenerateUeventsForDir(DIR* d, const ListenerCallback& callback) const;
 
     android::base::unique_fd device_fd_;
 };

init/ueventd.cpp

@@ -138,7 +138,7 @@ void ColdBoot::RegenerateUevents() {
         HandleFirmwareEvent(uevent);
 
         uevent_queue_.emplace_back(std::move(uevent));
-        return RegenerationAction::kContinue;
+        return ListenerAction::kContinue;
     });
 }
 
@@ -266,9 +266,10 @@ int ueventd_main(int argc, char** argv) {
         cold_boot.Run();
     }
 
-    uevent_listener.DoPolling([&device_handler](const Uevent& uevent) {
+    uevent_listener.Poll([&device_handler](const Uevent& uevent) {
         HandleFirmwareEvent(uevent);
         device_handler.HandleDeviceEvent(uevent);
+        return ListenerAction::kContinue;
     });
 
     return 0;