Minor follow-up initrd feedback items (#14186)

Co-authored-by: Ben Hillis <benhill@ntdev.microsoft.com>

Author: benhillis

.gitignore

@@ -10,7 +10,6 @@ tmp
 *.user
 *.csproj
 *.vcxproj
-*.targets
 *.filters
 *.pdb
 *.lib
@@ -42,7 +41,6 @@ linux/init
 initrd/init
 bin/
 *.nupkg
-build/
 generated/
 *.nuspec
 test/linux/unit_tests/wsl_unit_tests
@@ -65,4 +63,7 @@ package/x64
 /appx-logs.txt
 tools/clang-format.exe
 /linux-crashes
-doc/site/
+doc/site/
+directory.build.targets
+test-storage/
+*.vhdx

msipackage/package.wix.in

@@ -540,8 +540,7 @@
             <!-- This needs to run after the registry is written because this action needs to read the install path -->
             <Custom Action="RegisterLspCategories" After="WriteRegistryValues" Condition='((not REMOVE~="ALL") or WIX_UPGRADE_DETECTED)  and (not UPGRADINGPRODUCTCODE) and (not SKIPLSP = 1)' />
 
-            <!-- Generate initrd.img from the init binary during installation.
-                 Only run when the tools component is being installed ($tools=3), not during same-version reinstalls -->
+            <!-- Generate initrd.img from the init binary whenever the tools component is being installed -->
             <Custom Action="CreateInitrd" After="RegisterLspCategories" Condition='$tools=3' />
 
             <!-- This needs to run before the registry is cleared because this action needs to read the install path.

src/windows/common/filesystem.cpp

@@ -1143,6 +1143,7 @@ void wsl::windows::common::filesystem::CreateCpioInitrd(_In_ const std::filesyst
         constexpr size_t headerSize = 110;
         const auto nameLen = strlen(name) + 1;
         const auto headerPadding = (4 - ((headerSize + nameLen) % 4)) % 4;
+        const bool isTrailer = strcmp(name, "TRAILER!!!") == 0;
 
         // Get current time for mtime. CPIO newc format only supports 32-bit fields.
         const auto mtime = static_cast<DWORD>(time(nullptr));
@@ -1165,10 +1166,10 @@ void wsl::windows::common::filesystem::CreateCpioInitrd(_In_ const std::filesyst
             "%08X"   // namesize
             "%08X",  // check
             0,
-            (fileSize > 0) ? 0100755 : 0,
+            isTrailer ? 0 : 0100755,
             0,
             0,
-            (fileSize > 0) ? 1 : 0,
+            isTrailer ? 0 : 1,
             mtime,
             fileSize,
             0,
@@ -1214,7 +1215,8 @@ void wsl::windows::common::filesystem::CreateCpioInitrd(_In_ const std::filesyst
     LARGE_INTEGER currentPos{};
     THROW_IF_WIN32_BOOL_FALSE(SetFilePointerEx(destFile.get(), {}, &currentPos, FILE_CURRENT));
 
-    const auto archivePadding = (archiveBlockSize - (currentPos.LowPart % archiveBlockSize)) % archiveBlockSize;
+    const auto currentSize = static_cast<ULONGLONG>(currentPos.QuadPart);
+    const auto archivePadding = static_cast<DWORD>((archiveBlockSize - (currentSize % archiveBlockSize)) % archiveBlockSize);
     if (archivePadding > 0)
     {
         char paddingBuffer[archiveBlockSize] = {0};

test/windows/SimpleTests.cpp

@@ -325,10 +325,10 @@ class SimpleTests
             THROW_IF_WIN32_BOOL_FALSE(GetFileSizeEx(cpioHandle.get(), &cpioSize));
             VERIFY_ARE_EQUAL(cpioSize.QuadPart % 512, 0LL); // Archive padded to 512-byte boundary
 
-            char header[110] = {};
+            char header[111] = {};
             DWORD bytesRead;
-            THROW_IF_WIN32_BOOL_FALSE(ReadFile(cpioHandle.get(), header, sizeof(header), &bytesRead, nullptr));
-            VERIFY_ARE_EQUAL(bytesRead, static_cast<DWORD>(sizeof(header)));
+            THROW_IF_WIN32_BOOL_FALSE(ReadFile(cpioHandle.get(), header, 110, &bytesRead, nullptr));
+            VERIFY_ARE_EQUAL(bytesRead, 110u);
 
             // Parse CPIO newc header: magic(6) ino mode uid gid nlink mtime filesize devmajor devminor rdevmajor rdevminor namesize check
             DWORD fileSize, nameSize;