From 66975b32cf9250c55db7b0b6541192a2d476c5e5 Mon Sep 17 00:00:00 2001 From: rong wang Date: Thu, 18 Jul 2024 19:09:34 +0800 Subject: [PATCH] fix: fix crash caused by multi-threaded access Remove the thread in `EventAdaptor` and use the main thread timer to dispatch events directly. `EventSource_GENL` asynchronously calls `MountCacher::updateMountPoints` to avoid multi-threaded access. Use `Q_GLOBAL_STATIC` to create a singleton, and do not allow static acquisition. Log: fix deepin-anything-server crash Bug: https://pms.uniontech.com/bug-view-264761.html --- src/server/backend/eventsource_genl.cpp | 44 +++++++++++----- src/server/backend/lib/eventadaptor.cpp | 70 ++++++++----------------- src/server/backend/lib/eventadaptor.h | 43 --------------- src/server/backend/lib/lftdisktool.cpp | 10 ++-- src/server/backend/lib/mountcacher.cpp | 24 ++------- src/server/backend/lib/mountcacher.h | 9 ++-- 6 files changed, 66 insertions(+), 134 deletions(-) diff --git a/src/server/backend/eventsource_genl.cpp b/src/server/backend/eventsource_genl.cpp index ee21443..c32e62b 100644 --- a/src/server/backend/eventsource_genl.cpp +++ b/src/server/backend/eventsource_genl.cpp @@ -195,28 +195,44 @@ void update_vfs_unnamed_device(const QSet &news) void EventSource_GENL::updatePartitions() { - // 有mount/unmount事件，更新mount cache - MountCacher::instance()->updateMountPoints(); - - QList mountList = MountCacher::instance()->getMountPointsByRoot("/"); - if (mountList.isEmpty()) { - nWarning("getMountPointsByRoot(/) return empty"); + /* Invokes updateMountPoints in the event loop of MountCacher to avoid multi-threaded access */ + QMetaObject::invokeMethod(MountCacher::instance(), "updateMountPoints", Qt::QueuedConnection); + + /* + * No use`MountCacher::instance()->getMountPointsByRoot("/")` to get mount list. + * This is to avoid multi-threaded access, and locks may cause dead locks. + */ + QString file_mountinfo_path("/proc/self/mountinfo"); + QFile file_mountinfo(file_mountinfo_path); + if (!file_mountinfo.open(QIODevice::ReadOnly | QIODevice::Text)) { + QByteArray ba = file_mountinfo_path.toLatin1(); + nWarning("open file failed: %s.", ba.data()); return; } + QByteArray mount_info; + mount_info = file_mountinfo.readAll(); + file_mountinfo.close(); unsigned int major, minor; + char mp[256], root[256], type[256], *line = mount_info.data(); QSet dlnfs_devs; QByteArray ba; partitions.clear(); nInfo("updatePartitions start."); - for(MountPoint info : mountList) { - unsigned long devno = info.deviceId; - major = major(devno); - minor = minor(devno); - partitions.insert(MKDEV(major, minor), info.mountTarget.toLocal8Bit()); - if (info.mountType == "fuse.dlnfs") { - ba.setNum(minor); - dlnfs_devs.insert(ba); + while (sscanf(line, "%*d %*d %u:%u %250s %250s %*s %*s %*s %250s %*s %*s\n", &major, &minor, root, mp, type) == 5) { + line = strchr(line, '\n') + 1; + + if (!major && strcmp(type, "fuse.dlnfs")) + continue; + + if (!strcmp(root, "/")) { + partitions.insert(MKDEV(major, minor), QByteArray(mp)); + nInfo("%u:%u, %s", major, minor, mp); + /* add monitoring for dlnfs device */ + if (!major && !strcmp(type, "fuse.dlnfs")) { + ba.setNum(minor); + dlnfs_devs.insert(ba); + } } } update_vfs_unnamed_device(dlnfs_devs); diff --git a/src/server/backend/lib/eventadaptor.cpp b/src/server/backend/lib/eventadaptor.cpp index b58e087..a5bef59 100644 --- a/src/server/backend/lib/eventadaptor.cpp +++ b/src/server/backend/lib/eventadaptor.cpp @@ -10,13 +10,9 @@ DAS_BEGIN_NAMESPACE EventAdaptor::EventAdaptor(QObject *parent) : QObject(parent) { - action_buffers.clear(); - - connect(&handle_timer, &QTimer::timeout, this, &EventAdaptor::onHandleEvent, Qt::QueuedConnection); - // 每500ms 触发一次事件 + connect(&handle_timer, &QTimer::timeout, this, &EventAdaptor::onHandleEvent); handle_timer.setInterval(500); handle_timer.start(); - jobFinished = true; } EventAdaptor::~EventAdaptor() @@ -26,55 +22,22 @@ EventAdaptor::~EventAdaptor() void EventAdaptor::pushEvent(QPair &action) { - QMutexLocker locker(&mutex); // 加锁 + QMutexLocker locker(&mutex); action_buffers.enqueue(action); - waitCondition.wakeAll(); } bool EventAdaptor::popEvent(QPair *action) { + QMutexLocker locker(&mutex); if (action_buffers.isEmpty()) { return false; } - QMutexLocker locker(&mutex); // 加锁 *action = action_buffers.dequeue(); - waitCondition.wakeAll(); return true; } void EventAdaptor::onHandleEvent() { - // 单线程保证索引串行更新 - if (!jobFinished) { - return; - } - QMetaObject::invokeMethod(this, "startWork", Qt::QueuedConnection); -} - - -bool EventAdaptor::ignoreAction(QByteArray &strArr, bool ignored) -{ - QString strPath = QString::fromLocal8Bit(strArr); - if (strPath.endsWith(".longname")) { - // 长文件名记录文件，直接忽略 - return true; - } - - //没有标记忽略前一条，则检查是否长文件目录 - if (!ignored) { - // 向上找到一个当前文件的挂载点且匹配文件系统类型 - if (MountCacher::instance()->pathMatchType(strPath, "fuse.dlnfs")) { - // 长文件目录，标记此条事件被忽略 - return true; - } - } - return false; -} - -void EventAdaptor::startWork() -{ - jobFinished = false; - bool pop = false; QList> tmpActions; bool ignored = false; @@ -92,17 +55,28 @@ void EventAdaptor::startWork() } } while (pop); - // Start the worker thread - TaskThread* taskThread = new TaskThread(this); - connect(taskThread, &TaskThread::workFinished, this, &EventAdaptor::handleTaskFinish); - connect(taskThread, &QThread::finished, taskThread, &QThread::deleteLater); - taskThread->setData(onHandler, tmpActions); - taskThread->start(); + if (!tmpActions.isEmpty()) { + onHandler(tmpActions); + } } -void EventAdaptor::handleTaskFinish() +bool EventAdaptor::ignoreAction(QByteArray &strArr, bool ignored) { - jobFinished = true; + QString strPath = QString::fromLocal8Bit(strArr); + if (strPath.endsWith(".longname")) { + // 长文件名记录文件，直接忽略 + return true; + } + + //没有标记忽略前一条，则检查是否长文件目录 + if (!ignored) { + // 向上找到一个当前文件的挂载点且匹配文件系统类型 + if (MountCacher::instance()->pathMatchType(strPath, "fuse.dlnfs")) { + // 长文件目录，标记此条事件被忽略 + return true; + } + } + return false; } DAS_END_NAMESPACE diff --git a/src/server/backend/lib/eventadaptor.h b/src/server/backend/lib/eventadaptor.h index 416652f..c8b9115 100644 --- a/src/server/backend/lib/eventadaptor.h +++ b/src/server/backend/lib/eventadaptor.h @@ -10,9 +10,7 @@ #include #include #include -#include #include -#include DAS_BEGIN_NAMESPACE @@ -31,10 +29,6 @@ class EventAdaptor : public QObject void pushEvent(QPair &action); bool popEvent(QPair *action); -public slots: - void startWork(); - void handleTaskFinish(); - public: OnHandleEvent onHandler; @@ -46,45 +40,8 @@ private slots: private: QMutex mutex; - QWaitCondition waitCondition; QQueue> action_buffers; QTimer handle_timer; - // 用于事件更新，串行进行 - bool jobFinished = true; -}; - -class TaskThread : public QThread -{ - Q_OBJECT -public: - explicit TaskThread(QObject *parent = nullptr) : QThread(parent) {} - ~TaskThread() override { - handleFunc = nullptr; - actionList.clear(); - deleteLater(); - } - void run() override - { - // 后台回调处理事件，更新索引 - if (handleFunc) - handleFunc(actionList); - - emit workFinished(); - } - -public slots: - void setData(OnHandleEvent callbackFunc, QList> &actions) - { - handleFunc = callbackFunc; - actionList = actions; - } - -signals: - void workFinished(); - -private: - OnHandleEvent handleFunc = nullptr; - QList> actionList; }; DAS_END_NAMESPACE diff --git a/src/server/backend/lib/lftdisktool.cpp b/src/server/backend/lib/lftdisktool.cpp index 8bfc6e4..05fed79 100644 --- a/src/server/backend/lib/lftdisktool.cpp +++ b/src/server/backend/lib/lftdisktool.cpp @@ -19,19 +19,17 @@ namespace LFTDiskTool { Q_GLOBAL_STATIC(DDiskManager, _global_diskManager) Q_LOGGING_CATEGORY(logN, "anything.normal.disktool", DEFAULT_MSG_TYPE) -static deepin_anything_server::MountCacher *s_mountCacher = deepin_anything_server::MountCacher::instance(); - QByteArray pathToSerialUri(const QString &path) { // 避免使用QDir/QStorageInfo, 如果IO被阻塞（U盘正在被扫描或网络盘断网），则导致卡顿或假死 // 向上找到路径的真实挂载点 - const QString mountPoint = s_mountCacher->findMountPointByPath(path); + const QString mountPoint = deepin_anything_server::MountCacher::instance()->findMountPointByPath(path); if (mountPoint.isEmpty()) { nWarning() << "pathToSerialUri findMountPointByPath NULL for:" << path; return QByteArray(); } - const QString device = s_mountCacher->getDeviceByPoint(mountPoint); + const QString device = deepin_anything_server::MountCacher::instance()->getDeviceByPoint(mountPoint); if (!device.startsWith("/dev/") || device.startsWith("/dev/loop") || device.compare("/dev/fuse") == 0) { nWarning() << "ingore device:" << device; return QByteArray(); @@ -51,7 +49,7 @@ QByteArray pathToSerialUri(const QString &path) if (block_id.isEmpty()) return QByteArray(); - const auto mount_info_map = s_mountCacher->getRootsByPoints({mountPoint.toLocal8Bit()}); + const auto mount_info_map = deepin_anything_server::MountCacher::instance()->getRootsByPoints({mountPoint.toLocal8Bit()}); QByteArray mount_root_path; // 只获取一个，返回就取第一个值 @@ -94,7 +92,7 @@ QByteArrayList fromSerialUri(const QByteArray &uri) if (_block_id == block_id) { const QByteArrayList &mount_points = block_obj->mountPoints(); - const auto mount_point_infos = s_mountCacher->getRootsByPoints(mount_points); + const auto mount_point_infos = deepin_anything_server::MountCacher::instance()->getRootsByPoints(mount_points); QByteArrayList pathList; for (QByteArray mount_point : mount_points) { diff --git a/src/server/backend/lib/mountcacher.cpp b/src/server/backend/lib/mountcacher.cpp index 3f2ed1d..08c7ab5 100644 --- a/src/server/backend/lib/mountcacher.cpp +++ b/src/server/backend/lib/mountcacher.cpp @@ -14,6 +14,9 @@ extern "C" { DAS_BEGIN_NAMESPACE +class _MountCacher : public MountCacher {}; +Q_GLOBAL_STATIC(_MountCacher, mountCacherGlobal) + /* error callback */ static int parser_errcb(libmnt_table *tb, const char *filename, int line) { @@ -34,14 +37,13 @@ struct SPMntTableDeleter MountCacher *MountCacher::instance() { - static MountCacher ins; - return &ins; + return mountCacherGlobal; } MountCacher::MountCacher(QObject *parent) : QObject(parent) { - mountPointList.clear(); + updateMountPoints(); } MountCacher::~MountCacher() @@ -103,10 +105,6 @@ QString MountCacher::findMountPointByPath(const QString &path, bool hardreal) { QString result; QString result_path = path; - if (hardreal) { - // 如果跳过虚拟，查找真实设备的挂载点，须检查挂载信息是否已获取 - checkCurrentMounts(); - } Q_FOREVER { char *checkpath = QFile::encodeName(result_path).data(); @@ -158,7 +156,6 @@ bool MountCacher::pathMatchType(const QString &path, const QString &type) { bool result= false; QString point = findMountPointByPath(path); - checkCurrentMounts(); for (MountPoint info: mountPointList) { if (point == info.mountTarget && type == info.mountType) { @@ -173,7 +170,6 @@ bool MountCacher::pathMatchType(const QString &path, const QString &type) QMap MountCacher::getRootsByPoints(const QByteArrayList &pointList) { QMap map; - checkCurrentMounts(); for (const QByteArray &point : pointList) { const QString target = QString(point); @@ -191,7 +187,6 @@ QMap MountCacher::getRootsByPoints(const QByteArrayList &po QString MountCacher::getDeviceByPoint(const QString &point) { QString device; - checkCurrentMounts(); for (MountPoint info: mountPointList) { if (point == info.mountTarget) { @@ -205,7 +200,6 @@ QString MountCacher::getDeviceByPoint(const QString &point) // 获取所有根为指定的挂载点, 不指定则返回全部挂载点信息 QList MountCacher::getMountPointsByRoot(const QString &root) { - checkCurrentMounts(); if (root == nullptr || !root.startsWith('/')) { return mountPointList; } @@ -219,14 +213,6 @@ QList MountCacher::getMountPointsByRoot(const QString &root) return list; } -void MountCacher::checkCurrentMounts() -{ - if (mountPointList.isEmpty()) { - nWarning() << "mountPointList is empty, updat it first."; - updateMountPoints(); - } -} - QDebug operator<<(QDebug debug, const MountPoint &mp) { QDebugStateSaver saver(debug); diff --git a/src/server/backend/lib/mountcacher.h b/src/server/backend/lib/mountcacher.h index 48efd1a..0c6cecb 100644 --- a/src/server/backend/lib/mountcacher.h +++ b/src/server/backend/lib/mountcacher.h @@ -29,8 +29,8 @@ class MountCacher : public QObject Q_DISABLE_COPY(MountCacher) public: + ~MountCacher(); static MountCacher *instance(); - bool updateMountPoints(); QString findMountPointByPath(const QString &path, bool hardreal = false); bool pathMatchType(const QString &path, const QString &type); @@ -43,11 +43,12 @@ class MountCacher : public QObject // 获取所有根为指定的挂载点, 不指定则返回全部挂载点信息 QList getMountPointsByRoot(const QString &root = nullptr); -private: +public slots: + bool updateMountPoints(); + +protected: explicit MountCacher(QObject *parent = nullptr); - ~MountCacher(); - void checkCurrentMounts(); private: QList mountPointList; };