Implement fetching physical QStorageInfo::blockSize() under Windows

This is implemented in two passes, first we try the older and
always available DeviceIoControl() function. This works most of
the time, though it might fail for example for storage devices
attached via USB. In this case, we try to dynamically load the
newer NtQueryVolumeInformationFile kernel function. Since this
is probably more expensive, we do this as fallback.

[ChangeLog][QtCore][QStorageInfo] The QStorageInfo::blockSize()
will now report the physical block size of a storage device under
Windows. Network mapped drives are not supported.

Fixes: QTBUG-93976
Change-Id: I08b5b879e5bf79c025e2e305196ec5c5fce8b20f
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

1 files changed, 141 insertions, 1 deletions

diff --git a/src/corelib/io/qstorageinfo_win.cpp b/src/corelib/io/qstorageinfo_win.cpp
index 5a65b78d63..d594551425 100644
--- a/src/corelib/io/qstorageinfo_win.cpp
+++ b/src/corelib/io/qstorageinfo_win.cpp
@@ -41,11 +41,13 @@
 
 #include <QtCore/qdir.h>
 #include <QtCore/qfileinfo.h>
+#include <QtCore/qmutex.h>
 #include <QtCore/qvarlengtharray.h>
 
 #include "qfilesystementry_p.h"
+#include "private/qsystemlibrary_p.h"
 
-#include <qt_windows.h>
+#include "qntdll_p.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -134,6 +136,9 @@ void QStorageInfoPrivate::doStat()
         return;
     device = getDevice(rootPath);
     retrieveDiskFreeSpace();
+
+    if (!queryStorageProperty())
+        queryFileFsSectorSizeInformation();
 }
 
 void QStorageInfoPrivate::retrieveVolumeInfo()
@@ -204,4 +209,139 @@ QStorageInfo QStorageInfoPrivate::root()
     return QStorageInfo(QDir::fromNativeSeparators(QFile::decodeName(qgetenv("SystemDrive"))));
 }
 
+bool QStorageInfoPrivate::queryStorageProperty()
+{
+    QString path = QDir::toNativeSeparators(uR"(\\.\)" + rootPath);
+    if (path.endsWith(u'\\'))
+        path.chop(1);
+
+    HANDLE handle = CreateFile(reinterpret_cast<const wchar_t *>(path.utf16()),
+                               0, // no access to the drive
+                               FILE_SHARE_READ | FILE_SHARE_WRITE,
+                               nullptr,
+                               OPEN_EXISTING,
+                               0,
+                               nullptr);
+    if (handle == INVALID_HANDLE_VALUE)
+        return false;
+
+    STORAGE_PROPERTY_QUERY spq;
+    memset(&spq, 0, sizeof(spq));
+    spq.PropertyId = StorageAccessAlignmentProperty;
+    spq.QueryType = PropertyStandardQuery;
+
+    STORAGE_ACCESS_ALIGNMENT_DESCRIPTOR saad;
+    memset(&saad, 0, sizeof(saad));
+
+    DWORD bytes = 0;
+    BOOL result = DeviceIoControl(handle,
+                                  IOCTL_STORAGE_QUERY_PROPERTY,
+                                  &spq, sizeof(spq),
+                                  &saad, sizeof(saad),
+                                  &bytes,
+                                  nullptr);
+    CloseHandle(handle);
+    if (result)
+        blockSize = saad.BytesPerPhysicalSector;
+    return result;
+}
+
+struct Helper
+{
+    QBasicMutex mutex;
+    QSystemLibrary ntdll {u"ntdll"_qs};
+};
+Q_GLOBAL_STATIC(Helper, gNtdllHelper)
+
+inline QFunctionPointer resolveSymbol(QSystemLibrary *ntdll, const char *name)
+{
+    QFunctionPointer symbolFunctionPointer = ntdll->resolve(name);
+    if (Q_UNLIKELY(!symbolFunctionPointer))
+        qWarning("Failed to resolve the symbol: %s", name);
+    return symbolFunctionPointer;
+}
+
+#define GENERATE_SYMBOL(symbolName, returnType, ...) \
+using Qt##symbolName = returnType (NTAPI *) (__VA_ARGS__); \
+static Qt##symbolName qt##symbolName = nullptr;
+
+#define RESOLVE_SYMBOL(name) \
+    do { \
+        qt##name = reinterpret_cast<Qt##name>(resolveSymbol(ntdll, #name)); \
+        if (!qt##name) \
+            return false; \
+    } while (false)
+
+GENERATE_SYMBOL(RtlInitUnicodeString, void, PUNICODE_STRING, PCWSTR);
+GENERATE_SYMBOL(NtCreateFile, NTSTATUS, PHANDLE, ACCESS_MASK, POBJECT_ATTRIBUTES,
+    PIO_STATUS_BLOCK, PLARGE_INTEGER, ULONG, ULONG, ULONG, ULONG, PVOID, ULONG);
+GENERATE_SYMBOL(NtQueryVolumeInformationFile, NTSTATUS, HANDLE, PIO_STATUS_BLOCK, PVOID, ULONG,
+    FS_INFORMATION_CLASS);
+
+void QStorageInfoPrivate::queryFileFsSectorSizeInformation()
+{
+    static bool symbolsResolved = [](auto ntdllHelper) {
+        QMutexLocker locker(&ntdllHelper->mutex);
+        auto ntdll = &ntdllHelper->ntdll;
+        if (!ntdll->isLoaded()) {
+            if (!ntdll->load()) {
+                qWarning("Unable to load ntdll.dll.");
+                return false;
+            }
+        }
+
+        RESOLVE_SYMBOL(RtlInitUnicodeString);
+        RESOLVE_SYMBOL(NtCreateFile);
+        RESOLVE_SYMBOL(NtQueryVolumeInformationFile);
+
+        return true;
+    }(gNtdllHelper());
+    if (!symbolsResolved)
+        return;
+
+    FILE_FS_SECTOR_SIZE_INFORMATION ffssi;
+    memset(&ffssi, 0, sizeof(ffssi));
+
+    HANDLE handle = nullptr;
+
+    OBJECT_ATTRIBUTES attrs;
+    memset(&attrs, 0, sizeof(attrs));
+
+    IO_STATUS_BLOCK isb;
+    memset(&isb, 0, sizeof(isb));
+
+    QString path = QDir::toNativeSeparators(uR"(\??\\)" + rootPath);
+    if (!path.endsWith(u'\\'))
+        path.append(u'\\');
+
+    UNICODE_STRING name;
+    qtRtlInitUnicodeString(&name, reinterpret_cast<const wchar_t *>(path.utf16()));
+
+    InitializeObjectAttributes(&attrs, &name, 0, nullptr, nullptr);
+
+    NTSTATUS status = qtNtCreateFile(&handle,
+                                     FILE_READ_ATTRIBUTES,
+                                     &attrs,
+                                     &isb,
+                                     nullptr,
+                                     FILE_ATTRIBUTE_NORMAL,
+                                     FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
+                                     FILE_OPEN,
+                                     0,
+                                     nullptr,
+                                     0);
+    if (!NT_SUCCESS(status))
+        return;
+
+    memset(&isb, 0, sizeof(isb));
+    status = qtNtQueryVolumeInformationFile(handle,
+                                            &isb,
+                                            &ffssi,
+                                            sizeof(ffssi),
+                                            FS_INFORMATION_CLASS(10)); // FileFsSectorSizeInformation
+    CloseHandle(handle);
+    if (NT_SUCCESS(status))
+        blockSize = ffssi.PhysicalBytesPerSectorForAtomicity;
+}
+
 QT_END_NAMESPACE