diff --git a/localization/strings/en-US/Resources.resw b/localization/strings/en-US/Resources.resw
index 55a700b83..95c21e1b8 100644
--- a/localization/strings/en-US/Resources.resw
+++ b/localization/strings/en-US/Resources.resw
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <root>
   <!--
     Microsoft ResX Schema
@@ -436,6 +436,13 @@ Arguments for managing Windows Subsystem for Linux:
             --from-file &lt;Path&gt;
                 Install a distribution from a local file.
 
+            --fs-type &lt;FsType&gt;
+                Specify the filesystem type to use for the distribution root.
+                Defaults to ext4.
+
+            --fs-mount-options &lt;Options&gt;
+                Specify additional mount options for the filesystem.
+
             --legacy
                 Use the legacy distribution manifest.
 
@@ -476,6 +483,9 @@ Arguments for managing Windows Subsystem for Linux:
             --resize &lt;MemoryString&gt;
                 Resize the disk of the distribution to the specified size.
 
+            --set-fs-mount-options &lt;Options&gt;
+                Set the filesystem mount options for the distribution root.
+
     --mount &lt;Disk&gt;
         Attaches and mounts a physical or virtual disk in all WSL 2 distributions.
 
@@ -551,6 +561,13 @@ Arguments for managing distributions in Windows Subsystem for Linux:
                 Specifies that the provided file is a .vhd or .vhdx file, not a tar file.
                 This operation makes a copy of the VHD file at the specified install location.
 
+            --fs-type &lt;FsType&gt;
+                Specify the filesystem type to use for the distribution root.
+                Defaults to ext4.
+
+            --fs-mount-options &lt;Options&gt;
+                Specify additional mount options for the filesystem.
+
     --import-in-place &lt;Distro&gt; &lt;FileName&gt;
         Imports the specified VHD file as a new distribution.
         This virtual hard disk must be formatted with the ext4 filesystem type.
@@ -591,10 +608,10 @@ Arguments for managing distributions in Windows Subsystem for Linux:
 "}{Locked="--debug-shell
 "}{Locked="--install "}{Locked="--list "}{Locked="--online'"}{Locked="--enable-wsl1
 "}{Locked="--fixed-vhd
-"}{Locked="--from-file "}{Locked="--legacy
+"}{Locked="--from-file "}{Locked="--fs-type "}{Locked="--fs-mount-options "}{Locked="--legacy
 "}{Locked="--location "}{Locked="--name "}{Locked="--no-distribution
 "}{Locked="--no-launch,"}{Locked="--version "}{Locked="--vhd-size "}{Locked="--web-download
-"}{Locked="--manage "}{Locked="--move "}{Locked="--set-sparse,"}{Locked="--set-default-user "}{Locked="--resize "}{Locked="--mount "}{Locked="--vhd
+"}{Locked="--manage "}{Locked="--move "}{Locked="--set-sparse,"}{Locked="--set-default-user "}{Locked="--resize "}{Locked="--set-fs-mount-options "}{Locked="--mount "}{Locked="--vhd
 "}{Locked="--bare
 "}{Locked="--name "}{Locked="--type "}{Locked="--options "}{Locked="--partition "}{Locked="--set-default-version "}{Locked="--shutdown
 "}{Locked="--force
@@ -1039,8 +1056,8 @@ Falling back to NAT networking.</value>
     <value>The distribution failed to start. Error code: {}, failure step: {}</value>
     <comment>{FixedPlaceholder="{}"}Command line arguments, file names and string inserts should not be translated</comment>
   </data>
-  <data name="MessageDiskCorrupted" xml:space="preserve">
-    <value>The distribution failed to start because its virtual disk is corrupted.</value>
+  <data name="MessageMountFailed" xml:space="preserve">
+    <value>The distribution failed to start because its virtual disk is corrupted, has an unexpected filesystem type, or has invalid mount options.</value>
   </data>
   <data name="MessageConfigKeyDuplicated" xml:space="preserve">
     <value>Duplicated config key '{}' in {}:{} (Conflicting key: '{}' in {}:{})</value>
diff --git a/src/linux/init/main.cpp b/src/linux/init/main.cpp
index e8e831502..259320e0f 100644
--- a/src/linux/init/main.cpp
+++ b/src/linux/init/main.cpp
@@ -65,6 +65,9 @@ Module Name:
 #include "SocketChannel.h"
 
 #define BSDTAR_PATH "/usr/bin/bsdtar"
+#define BTRFS_CREATE_ARG "create"
+#define BTRFS_PATH "/usr/sbin/btrfs"
+#define BTRFS_SUBVOLUME_ARG "subvolume"
 #define BINFMT_REGISTER_STRING ":" LX_INIT_BINFMT_NAME ":M::MZ::" LX_INIT_PATH ":FP\n"
 #define BINFMT_PATH PROCFS_PATH "/sys/fs/binfmt_misc"
 #define CHRONY_CONF_PATH ETC_PATH "/chrony.conf"
@@ -136,7 +139,8 @@ int EnableInterface(int Socket, const char* Name);
 
 int ExportToSocket(const char* Source, int Socket, int ErrorSocket, unsigned int flags);
 
-int FormatDevice(unsigned int Lun);
+int FormatDevice(unsigned int Lun, const char* FsType);
+int CreateBtrfsSubvolumeOnDevice(unsigned int Lun, const char* MountOptions);
 
 std::string GetLunDeviceName(unsigned int Lun);
 
@@ -901,19 +905,23 @@ Return Value:
     return Result;
 }
 
-int FormatDevice(unsigned int Lun)
+int FormatDevice(unsigned int Lun, const char* FsType)
 
 /*++
 
 Routine Description:
 
-    This routine formats the specified SCSI device with the ext4 file system.
-    N.B. The group size was chosen based on the best practices for Linux VHDs:
+    This routine formats the specified SCSI device with the <FsType> file system.
+
+    N.B. The ext4 group size was chosen based on the best practices for Linux VHDs:
          https://docs.microsoft.com/en-us/windows-server/virtualization/hyper-v/best-practices-for-running-linux-on-hyper-v
 
+    N.B. The xfs data section options (-d) are also determined based on the VHD sector size of 1MB, as suggested in the link above.
+
 Arguments:
 
     Lun - Supplies the LUN number of the SCSI device.
+    FsType - The filesystem type to format the device with.
 
 Return Value:
 
@@ -927,7 +935,30 @@ try
 
     WaitForBlockDevice(DevicePath.c_str());
 
-    std::string CommandLine = std::format("/usr/sbin/mkfs.ext4 -G 4096 '{}'", DevicePath);
+    if (FsType == nullptr)
+    {
+        FsType = "ext4";
+    }
+
+    std::string CommandLine;
+    if (strcmp(FsType, "ext4") == 0)
+    {
+        CommandLine = std::format("/usr/sbin/mkfs.ext4 -G 4096 '{}'", DevicePath);
+    }
+    else if (strcmp(FsType, "btrfs") == 0)
+    {
+        CommandLine = std::format("/usr/sbin/mkfs.btrfs '{}'", DevicePath);
+    }
+    else if (strcmp(FsType, "xfs") == 0)
+    {
+        CommandLine = std::format("/usr/sbin/mkfs.xfs -s size=4096 -d su=1m,sw=1 '{}'", DevicePath);
+    }
+    else
+    {
+        LOG_ERROR("Unsupported filesystem type: {}", FsType);
+        errno = ENOSYS;
+        return -1;
+    }
     if (UtilExecCommandLine(CommandLine.c_str(), nullptr) < 0)
     {
         return -1;
@@ -937,6 +968,84 @@ try
 }
 CATCH_RETURN_ERRNO()
 
+int CreateBtrfsSubvolumeOnDevice(unsigned int Lun, const char* MountOptions)
+/*++
+    This routine creates a btrfs subvolume on the specified SCSI device.
+    It is a no-op if there is no subvolume name in the mount options or
+    the subvolume already exists.
+
+Arguments:
+
+    Lun - Supplies the LUN number of the SCSI device.
+    MountOptions - The mount options to use when mounting the device.
+        The subvolume name is extracted from these options.
+
+Return Value:
+
+    0 on success, < 0 on failure.
+--*/
+try
+{
+    if (MountOptions == nullptr)
+    {
+        return 0;
+    }
+
+    std::string_view options(MountOptions);
+    std::string_view subvolName;
+
+    size_t pos = 0;
+    while (pos < options.size())
+    {
+        size_t end = options.find(',', pos);
+        if (end == std::string_view::npos)
+        {
+            end = options.size();
+        }
+
+        std::string_view option = options.substr(pos, end - pos);
+        if (option.starts_with("subvol="))
+        {
+            subvolName = option.substr(7); // Skip "subvol="
+            break;
+        }
+
+        pos = end + 1;
+    }
+
+    if (subvolName.empty())
+    {
+        return 0;
+    }
+
+    std::string DevicePath = GetLunDevicePath(Lun);
+    std::string TempMountPath;
+    THROW_LAST_ERROR_IF(CreateTempDirectory("/tmp", TempMountPath) < 0);
+
+    auto unmountOnExit = wil::scope_exit([&TempMountPath]() {
+        umount(TempMountPath.c_str());
+        rmdir(TempMountPath.c_str());
+    });
+
+    THROW_LAST_ERROR_IF(UtilMount(DevicePath.c_str(), TempMountPath.c_str(), "btrfs", 0, nullptr, c_defaultRetryTimeout) < 0);
+
+    std::string SubvolPath = std::format("{}/{}", TempMountPath, subvolName);
+
+    struct stat st;
+    if (stat(SubvolPath.c_str(), &st) == 0)
+    {
+        return 0;
+    }
+
+    THROW_LAST_ERROR_IF(errno != ENOENT);
+
+    const char* Argv[] = {BTRFS_PATH, BTRFS_SUBVOLUME_ARG, BTRFS_CREATE_ARG, SubvolPath.c_str(), nullptr};
+    THROW_LAST_ERROR_IF(UtilCreateProcessAndWait(Argv[0], Argv) < 0);
+
+    return 0;
+}
+CATCH_RETURN_ERRNO()
+
 std::string GetLunDeviceName(unsigned int Lun)
 
 /*++
@@ -2738,13 +2847,20 @@ void ProcessImportExportMessage(gsl::span<gsl::byte> Buffer, wsl::shared::Socket
             ListenSocket = UtilListenVsockAnyPort(&ListenAddress, 2, true);
             THROW_LAST_ERROR_IF(!ListenSocket);
 
+            auto* FsType = wsl::shared::string::FromSpan(Buffer, Message->FsTypeOffset);
+            auto* MountOptions = wsl::shared::string::FromSpan(Buffer, Message->MountOptionsOffset);
+
             if (Message->Header.MessageType == LxMiniInitMessageImport)
             {
-                THROW_LAST_ERROR_IF(FormatDevice(Message->DeviceId) < 0);
+                THROW_LAST_ERROR_IF(FormatDevice(Message->DeviceId, FsType) < 0);
+
+                if (FsType != nullptr && strcmp(FsType, "btrfs") == 0)
+                {
+                    // create the subvolume if specified in mount options
+                    THROW_LAST_ERROR_IF(CreateBtrfsSubvolumeOnDevice(Message->DeviceId, MountOptions) < 0);
+                }
             }
 
-            auto* FsType = wsl::shared::string::FromSpan(Buffer, Message->FsTypeOffset);
-            auto* MountOptions = wsl::shared::string::FromSpan(Buffer, Message->MountOptionsOffset);
             THROW_LAST_ERROR_IF(MountDevice(Message->MountDeviceType, Message->DeviceId, DISTRO_PATH, FsType, Message->Flags, MountOptions) < 0);
 
             Result = 0;
diff --git a/src/windows/common/WslClient.cpp b/src/windows/common/WslClient.cpp
index 72daeecae..239a68cb2 100644
--- a/src/windows/common/WslClient.cpp
+++ b/src/windows/common/WslClient.cpp
@@ -319,12 +319,16 @@ int ImportDistribution(_In_ std::wstring_view commandLine)
     std::filesystem::path filePath;
     ULONG flags = LXSS_IMPORT_DISTRO_FLAGS_NO_OOBE;
     DWORD version = LXSS_WSL_VERSION_DEFAULT;
+    std::optional<std::wstring> fsType;
+    std::optional<std::wstring> fsMountOptions;
 
     parser.AddPositionalArgument(name, 0);
     parser.AddPositionalArgument(AbsolutePath(installPath), 1);
     parser.AddPositionalArgument(filePath, 2);
     parser.AddArgument(WslVersion(version), WSL_IMPORT_ARG_VERSION);
     parser.AddArgument(SetFlag<ULONG, LXSS_IMPORT_DISTRO_FLAGS_VHD>{flags}, WSL_IMPORT_ARG_VHD);
+    parser.AddArgument(fsType, WSL_IMPORT_ARG_FS_TYPE);
+    parser.AddArgument(fsMountOptions, WSL_IMPORT_ARG_FS_MOUNT_OPTIONS);
 
     parser.Parse();
 
@@ -385,7 +389,15 @@ int ImportDistribution(_In_ std::wstring_view commandLine)
     {
         wsl::windows::common::HandleConsoleProgressBar progressBar(fileHandle, Localization::MessageImportProgress());
         wsl::windows::common::SvcComm service;
-        service.RegisterDistribution(name, version, fileHandle, installPath->c_str(), flags);
+        service.RegisterDistribution(
+            name,
+            version,
+            fileHandle,
+            installPath->c_str(),
+            flags,
+            std::nullopt,
+            fsType.has_value() ? fsType->c_str() : nullptr,
+            fsMountOptions.has_value() ? fsMountOptions->c_str() : nullptr);
     }
 
     directory_cleanup.release();
@@ -458,6 +470,8 @@ int Install(_In_ std::wstring_view commandLine)
     bool noDistribution = false;
     bool legacy = false;
     bool webDownload = IsWindowsServer();
+    std::optional<std::wstring> fsType;
+    std::optional<std::wstring> fsMountOptions;
 
     ArgumentParser parser(std::wstring{commandLine}, WSL_BINARY_NAME);
     parser.AddPositionalArgument(distroArgument, 0);
@@ -475,6 +489,8 @@ int Install(_In_ std::wstring_view commandLine)
     parser.AddArgument(g_promptBeforeExit, WSL_INSTALL_ARG_PROMPT_BEFORE_EXIT_OPTION);
     parser.AddArgument(SizeString(vhdSize), WSL_INSTALL_ARG_VHD_SIZE);
     parser.AddArgument(fixedVhd, WSL_INSTALL_ARG_FIXED_VHD);
+    parser.AddArgument(fsType, WSL_INSTALL_ARG_FS_TYPE);
+    parser.AddArgument(fsMountOptions, WSL_INSTALL_ARG_FS_MOUNT_OPTIONS);
 
     parser.Parse();
 
@@ -531,7 +547,9 @@ int Install(_In_ std::wstring_view commandLine)
             file,
             location.has_value() ? location->c_str() : nullptr,
             fixedVhd ? LXSS_IMPORT_DISTRO_FLAGS_FIXED_VHD : 0,
-            vhdSize);
+            vhdSize,
+            fsType.has_value() ? fsType->c_str() : nullptr,
+            fsMountOptions.has_value() ? fsMountOptions->c_str() : nullptr);
 
         wsl::windows::common::wslutil::PrintMessage(Localization::MessageDistributionInstalled(installedName.get()), stdout);
 
@@ -557,7 +575,7 @@ int Install(_In_ std::wstring_view commandLine)
     if (!noDistribution && (legacy || !rebootRequired))
     {
         auto result = WslInstall::InstallDistribution(
-            installResult, distroArgument, version, !noLaunchAfterInstall, webDownload, legacy, fixedVhd, name, location, vhdSize);
+            installResult, distroArgument, version, !noLaunchAfterInstall, webDownload, legacy, fixedVhd, name, location, vhdSize, fsType, fsMountOptions);
 
         std::optional<std::wstring> flavor;
         if (installResult.Distribution.has_value())
@@ -891,6 +909,7 @@ int Manage(_In_ std::wstring_view commandLine)
     std::optional<std::wstring> move;
     std::optional<std::wstring> defaultUser;
     std::optional<uint64_t> resize;
+    std::optional<std::wstring> fsMountOptions;
     bool allowUnsafe = false;
 
     ArgumentParser parser(std::wstring{commandLine}, WSL_BINARY_NAME, 0);
@@ -899,6 +918,7 @@ int Manage(_In_ std::wstring_view commandLine)
     parser.AddArgument(AbsolutePath(move), WSL_MANAGE_ARG_MOVE_OPTION_LONG, WSL_MANAGE_ARG_MOVE_OPTION);
     parser.AddArgument(defaultUser, WSL_MANAGE_ARG_SET_DEFAULT_USER_OPTION_LONG);
     parser.AddArgument(SizeString(resize), WSL_MANAGE_ARG_RESIZE_OPTION_LONG, WSL_MANAGE_ARG_RESIZE_OPTION);
+    parser.AddArgument(fsMountOptions, WSL_MANAGE_ARG_SET_FS_MOUNT_OPTIONS_LONG);
     parser.AddArgument(allowUnsafe, WSL_MANAGE_ARG_ALLOW_UNSAFE);
     parser.Parse();
 
@@ -907,7 +927,7 @@ int Manage(_In_ std::wstring_view commandLine)
     wsl::windows::common::SvcComm service;
     auto distroGuid = service.GetDistributionId(distribution);
 
-    if (sparse.has_value() + move.has_value() + defaultUser.has_value() + resize.has_value() != 1)
+    if (sparse.has_value() + move.has_value() + defaultUser.has_value() + resize.has_value() + fsMountOptions.has_value() != 1)
     {
         THROW_HR(WSL_E_INVALID_USAGE);
     }
@@ -954,6 +974,10 @@ int Manage(_In_ std::wstring_view commandLine)
     {
         THROW_IF_FAILED(service.ResizeDistribution(&distroGuid, resize.value()));
     }
+    else if (fsMountOptions)
+    {
+        service.SetFsMountOptions(&distroGuid, fsMountOptions->c_str());
+    }
 
     wsl::windows::common::wslutil::PrintSystemError(ERROR_SUCCESS);
     return 0;
diff --git a/src/windows/common/WslInstall.cpp b/src/windows/common/WslInstall.cpp
index 1aab74850..648f13dee 100644
--- a/src/windows/common/WslInstall.cpp
+++ b/src/windows/common/WslInstall.cpp
@@ -101,7 +101,9 @@ HRESULT WslInstall::InstallDistribution(
     _In_ bool fixedVhd,
     _In_ const std::optional<std::wstring>& localName,
     _In_ const std::optional<std::wstring>& location,
-    _In_ const std::optional<uint64_t>& vhdSize)
+    _In_ const std::optional<uint64_t>& vhdSize,
+    _In_ const std::optional<std::wstring>& fsType,
+    _In_ const std::optional<std::wstring>& fsMountOptions)
 try
 {
     wsl::windows::common::ExecutionContext context(wsl::windows::common::InstallDistro);
@@ -143,7 +145,7 @@ try
         if (const auto* distro = std::get_if<ModernDistributionVersion>(&*installResult.Distribution))
         {
             std::tie(installResult.Name, installResult.Id) =
-                InstallModernDistribution(*distro, version, localName, location, vhdSize, fixedVhd);
+                InstallModernDistribution(*distro, version, localName, location, vhdSize, fixedVhd, fsType, fsMountOptions);
 
             installResult.InstalledViaGitHub = true;
         }
@@ -153,7 +155,9 @@ try
                 {localName.has_value(), WSL_INSTALL_ARG_NAME_LONG},
                 {location.has_value(), WSL_INSTALL_ARG_LOCATION_LONG},
                 {vhdSize.has_value(), WSL_INSTALL_ARG_VHD_SIZE},
-                {fixedVhd, WSL_INSTALL_ARG_FIXED_VHD}};
+                {fixedVhd, WSL_INSTALL_ARG_FIXED_VHD},
+                {fsType.has_value(), WSL_INSTALL_ARG_FS_TYPE},
+                {fsMountOptions.has_value(), WSL_INSTALL_ARG_FS_MOUNT_OPTIONS}};
 
             for (const auto& [condition, argument] : unsupportedArguments)
             {
@@ -272,7 +276,9 @@ std::pair<std::wstring, GUID> WslInstall::InstallModernDistribution(
     const std::optional<std::wstring>& name,
     const std::optional<std::wstring>& location,
     const std::optional<uint64_t>& vhdSize,
-    const bool fixedVhd)
+    const bool fixedVhd,
+    const std::optional<std::wstring>& fsType,
+    const std::optional<std::wstring>& fsMountOptions)
 {
     wsl::windows::common::SvcComm service;
 
@@ -322,7 +328,9 @@ std::pair<std::wstring, GUID> WslInstall::InstallModernDistribution(
         file.get(),
         location.has_value() ? location->c_str() : nullptr,
         fixedVhd ? LXSS_IMPORT_DISTRO_FLAGS_FIXED_VHD : 0,
-        vhdSize);
+        vhdSize,
+        fsType.has_value() ? fsType->c_str() : nullptr,
+        fsMountOptions.has_value() ? fsMountOptions->c_str() : nullptr);
 
     return {installedName.get(), id};
 }
\ No newline at end of file
diff --git a/src/windows/common/WslInstall.h b/src/windows/common/WslInstall.h
index beee2fa24..89082d697 100644
--- a/src/windows/common/WslInstall.h
+++ b/src/windows/common/WslInstall.h
@@ -38,7 +38,9 @@ class WslInstall
         _In_ bool fixedVhd,
         _In_ const std::optional<std::wstring>& localName,
         _In_ const std::optional<std::wstring>& location,
-        _In_ const std::optional<uint64_t>& vhdSize);
+        _In_ const std::optional<uint64_t>& vhdSize,
+        _In_ const std::optional<std::wstring>& fsType,
+        _In_ const std::optional<std::wstring>& fsMountOptions);
 
     static std::pair<bool, std::vector<std::wstring>> CheckForMissingOptionalComponents(_In_ bool requireWslOptionalComponent);
 
@@ -50,5 +52,7 @@ class WslInstall
         const std::optional<std::wstring>& name,
         const std::optional<std::wstring>& location,
         const std::optional<uint64_t>& vhdSize,
-        const bool fixedVhd);
+        const bool fixedVhd,
+        const std::optional<std::wstring>& fsType,
+        const std::optional<std::wstring>& fsMountOptions);
 };
diff --git a/src/windows/common/svccomm.cpp b/src/windows/common/svccomm.cpp
index cc066c2b8..53f2a047c 100644
--- a/src/windows/common/svccomm.cpp
+++ b/src/windows/common/svccomm.cpp
@@ -914,6 +914,8 @@ std::pair<GUID, wil::unique_cotaskmem_string> wsl::windows::common::SvcComm::Reg
     _In_ LPCWSTR TargetDirectory,
     _In_ ULONG Flags,
     _In_ std::optional<uint64_t> VhdSize,
+    _In_opt_ LPCWSTR FsType,
+    _In_opt_ LPCWSTR FsMountOptions,
     _In_opt_ LPCWSTR PackageFamilyName) const
 {
     ClientExecutionContext context;
@@ -939,6 +941,8 @@ std::pair<GUID, wil::unique_cotaskmem_string> wsl::windows::common::SvcComm::Reg
             TargetDirectory,
             Flags,
             VhdSize.value_or(0),
+            FsType,
+            FsMountOptions,
             PackageFamilyName,
             &installedName,
             context.OutError(),
@@ -954,6 +958,8 @@ std::pair<GUID, wil::unique_cotaskmem_string> wsl::windows::common::SvcComm::Reg
             TargetDirectory,
             Flags,
             VhdSize.value_or(0),
+            FsType,
+            FsMountOptions,
             PackageFamilyName,
             &installedName,
             context.OutError(),
@@ -982,6 +988,13 @@ wsl::windows::common::SvcComm::SetSparse(_In_ LPCGUID DistroGuid, _In_ BOOL Spar
     RETURN_HR(m_userSession->SetSparse(DistroGuid, Sparse, AllowUnsafe, context.OutError()));
 }
 
+void wsl::windows::common::SvcComm::SetFsMountOptions(_In_ LPCGUID DistroGuid, _In_ LPCWSTR FsMountOptions) const
+{
+    ClientExecutionContext context;
+
+    THROW_IF_FAILED(m_userSession->SetFsMountOptions(DistroGuid, FsMountOptions, context.OutError()));
+}
+
 HRESULT
 wsl::windows::common::SvcComm::ResizeDistribution(_In_ LPCGUID DistroGuid, _In_ ULONG64 NewSize) const
 {
diff --git a/src/windows/common/svccomm.hpp b/src/windows/common/svccomm.hpp
index 3a6423a58..2b0dc820e 100644
--- a/src/windows/common/svccomm.hpp
+++ b/src/windows/common/svccomm.hpp
@@ -86,6 +86,8 @@ class SvcComm
         _In_ LPCWSTR TargetDirectory,
         _In_ ULONG Flags,
         _In_ std::optional<uint64_t> VhdSize = std::nullopt,
+        _In_opt_ LPCWSTR FsType = nullptr,
+        _In_opt_ LPCWSTR FsMountOptions = nullptr,
         _In_opt_ LPCWSTR PackageFamilyName = nullptr) const;
 
     HRESULT
@@ -96,6 +98,8 @@ class SvcComm
     HRESULT
     SetSparse(_In_ LPCGUID DistroGuid, _In_ BOOL Sparse, _In_ BOOL AllowUnsafe) const;
 
+    void SetFsMountOptions(_In_ LPCGUID DistroGuid, _In_ LPCWSTR FsMountOptions) const;
+
     HRESULT
     SetVersion(_In_ LPCGUID DistroGuid, _In_ ULONG Version) const;
 
diff --git a/src/windows/common/wslutil.cpp b/src/windows/common/wslutil.cpp
index 421caf89e..40121f741 100644
--- a/src/windows/common/wslutil.cpp
+++ b/src/windows/common/wslutil.cpp
@@ -81,7 +81,7 @@ static const std::map<HRESULT, LPCWSTR> g_commonErrors{
     X(WSL_E_WSL1_DISABLED),
     X(WSL_E_VIRTUAL_MACHINE_PLATFORM_REQUIRED),
     X(WSL_E_LOCAL_SYSTEM_NOT_SUPPORTED),
-    X(WSL_E_DISK_CORRUPTED),
+    X(WSL_E_MOUNT_FAILED),
     X(WSL_E_DISTRIBUTION_NAME_NEEDED),
     X(WSL_E_INVALID_JSON),
     X(WSL_E_VM_CRASHED),
@@ -887,8 +887,8 @@ std::wstring wsl::windows::common::wslutil::GetErrorString(HRESULT result)
     case WSL_E_LOCAL_SYSTEM_NOT_SUPPORTED:
         return Localization::MessageLocalSystemNotSupported();
 
-    case WSL_E_DISK_CORRUPTED:
-        return Localization::MessageDiskCorrupted();
+    case WSL_E_MOUNT_FAILED:
+        return Localization::MessageMountFailed();
 
     case WSL_E_NOT_A_LINUX_DISTRO:
         return Localization::MessageInvalidDistributionTar();
diff --git a/src/windows/inc/wsl.h b/src/windows/inc/wsl.h
index ce4b9e430..2a00090b5 100644
--- a/src/windows/inc/wsl.h
+++ b/src/windows/inc/wsl.h
@@ -29,6 +29,8 @@ Module Name:
 #define WSL_EXPORT_ARG_VHD_OPTION L"--vhd"
 #define WSL_HELP_ARG L"--help"
 #define WSL_IMPORT_ARG L"--import"
+#define WSL_IMPORT_ARG_FS_MOUNT_OPTIONS L"--fs-mount-options"
+#define WSL_IMPORT_ARG_FS_TYPE L"--fs-type"
 #define WSL_IMPORT_ARG_STDIN L"-"
 #define WSL_IMPORT_ARG_VERSION L"--version"
 #define WSL_IMPORT_ARG_VHD L"--vhd"
@@ -40,6 +42,8 @@ Module Name:
 #define WSL_INSTALL_ARG_FIXED_VHD L"--fixed-vhd"
 #define WSL_INSTALL_ARG_FROM_FILE_OPTION L'f'
 #define WSL_INSTALL_ARG_FROM_FILE_LONG L"--from-file"
+#define WSL_INSTALL_ARG_FS_MOUNT_OPTIONS L"--fs-mount-options"
+#define WSL_INSTALL_ARG_FS_TYPE L"--fs-type"
 #define WSL_INSTALL_ARG_LEGACY_LONG L"--legacy"
 #define WSL_INSTALL_ARG_LOCATION_OPTION L'l'
 #define WSL_INSTALL_ARG_LOCATION_LONG L"--location"
@@ -75,6 +79,7 @@ Module Name:
 #define WSL_MANAGE_ARG_SET_SPARSE_OPTION L's'
 #define WSL_MANAGE_ARG_SET_SPARSE_OPTION_LONG L"--set-sparse"
 #define WSL_MANAGE_ARG_SET_DEFAULT_USER_OPTION_LONG L"--set-default-user"
+#define WSL_MANAGE_ARG_SET_FS_MOUNT_OPTIONS_LONG L"--set-fs-mount-options"
 #define WSL_MOUNT_ARG L"--mount"
 #define WSL_MOUNT_ARG_VHD_OPTION_LONG L"--vhd"
 #define WSL_MOUNT_ARG_BARE_OPTION_LONG L"--bare"
diff --git a/src/windows/service/exe/DistributionRegistration.cpp b/src/windows/service/exe/DistributionRegistration.cpp
index bfda98c2f..02125e563 100644
--- a/src/windows/service/exe/DistributionRegistration.cpp
+++ b/src/windows/service/exe/DistributionRegistration.cpp
@@ -57,7 +57,18 @@ DistributionRegistration DistributionRegistration::Open(HKEY LxssKey, const GUID
 }
 
 DistributionRegistration DistributionRegistration::Create(
-    HKEY LxssKey, const std::optional<GUID>& Id, LPCWSTR Name, ULONG Version, LPCWSTR BasePath, ULONG Flags, ULONG DefaultUID, LPCWSTR PackageFamilyName, LPCWSTR VhdFileName, bool EnableOobe)
+    HKEY LxssKey,
+    const std::optional<GUID>& Id,
+    LPCWSTR Name,
+    ULONG Version,
+    LPCWSTR BasePath,
+    ULONG Flags,
+    ULONG DefaultUID,
+    LPCWSTR PackageFamilyName,
+    LPCWSTR VhdFileName,
+    LPCWSTR FsType,
+    LPCWSTR FsMountOptions,
+    bool EnableOobe)
 {
     std::wstring distroGuidString;
     GUID distroId{};
@@ -112,6 +123,26 @@ DistributionRegistration DistributionRegistration::Create(
         distribution.Write(Property::VhdFileName, VhdFileName);
     }
 
+    if (ARGUMENT_PRESENT(FsType))
+    {
+        distribution.Write(Property::FsType, FsType);
+    }
+
+    if (ARGUMENT_PRESENT(FsMountOptions))
+    {
+        distribution.Write(Property::FsMountOptions, FsMountOptions);
+    }
+    else if (ARGUMENT_PRESENT(FsType) && wcscmp(FsType, LXSS_DISTRO_DEFAULT_FS_TYPE) != 0)
+    {
+        // FsType-specific default mount options
+        if (wcscmp(FsType, L"ext4") == 0)
+            distribution.Write(Property::FsMountOptions, LXSS_DISTRO_DEFAULT_FS_MOUNT_OPTIONS_EXT4);
+        else if (wcscmp(FsType, L"btrfs") == 0)
+            distribution.Write(Property::FsMountOptions, LXSS_DISTRO_DEFAULT_FS_MOUNT_OPTIONS_BTRFS);
+        else if (wcscmp(FsType, L"xfs") == 0)
+            distribution.Write(Property::FsMountOptions, LXSS_DISTRO_DEFAULT_FS_MOUNT_OPTIONS_XFS);
+    }
+
     // Dismiss the scope exit member so the key is persisted.
     cleanup.release();
     return distribution;
diff --git a/src/windows/service/exe/DistributionRegistration.h b/src/windows/service/exe/DistributionRegistration.h
index 61fc161d4..81e3fb612 100644
--- a/src/windows/service/exe/DistributionRegistration.h
+++ b/src/windows/service/exe/DistributionRegistration.h
@@ -55,6 +55,8 @@ class DistributionRegistration
         ULONG DefaultUID,
         LPCWSTR PackageFamilyName,
         LPCWSTR VhdFileName,
+        LPCWSTR FsType,
+        LPCWSTR FsMountOptions,
         bool EnableOobe);
 
     static DistributionRegistration Open(HKEY LxssKey, const GUID& Id);
@@ -91,6 +93,8 @@ namespace Property {
     inline DistributionPropertyWithDefault<LPCWSTR> PackageFamilyName{L"PackageFamilyName", L""};
     inline DistributionPropertyWithDefault<LPCWSTR> KernelCommandLine{L"KernelCommandLine", L""};
     inline DistributionPropertyWithDefault<LPCWSTR> VhdFileName{L"VhdFileName", LXSS_VM_MODE_VHD_NAME};
+    inline DistributionPropertyWithDefault<LPCWSTR> FsType{L"FsType", LXSS_DISTRO_DEFAULT_FS_TYPE};
+    inline DistributionPropertyWithDefault<LPCWSTR> FsMountOptions{L"FsMountOptions", LXSS_DISTRO_DEFAULT_FS_MOUNT_OPTIONS};
     inline ExpectedProperty<LPCWSTR> Name{L"DistributionName"};
     inline ExpectedProperty<LPCWSTR> BasePath{L"BasePath"};
     inline DistributionProperty<LPCWSTR> Flavor{L"Flavor"};
diff --git a/src/windows/service/exe/LxssCreateProcess.h b/src/windows/service/exe/LxssCreateProcess.h
index 8e1c704a4..8fd4bc602 100644
--- a/src/windows/service/exe/LxssCreateProcess.h
+++ b/src/windows/service/exe/LxssCreateProcess.h
@@ -110,6 +110,8 @@ typedef struct _LXSS_DISTRO_CONFIGURATION
     std::filesystem::path BasePath;
     std::wstring PackageFamilyName;
     std::filesystem::path VhdFilePath;
+    std::wstring FsType;
+    std::wstring FsMountOptions;
     ULONG Flags;
     std::wstring Flavor;
     std::wstring OsVersion;
diff --git a/src/windows/service/exe/LxssUserSession.cpp b/src/windows/service/exe/LxssUserSession.cpp
index 2ad6469c9..a2ec0975f 100644
--- a/src/windows/service/exe/LxssUserSession.cpp
+++ b/src/windows/service/exe/LxssUserSession.cpp
@@ -383,6 +383,8 @@ HRESULT STDMETHODCALLTYPE LxssUserSession::RegisterDistribution(
     _In_ LPCWSTR TargetDirectory,
     _In_ ULONG Flags,
     _In_ ULONG64 VhdSize,
+    _In_opt_ LPCWSTR FsType,
+    _In_opt_ LPCWSTR FsMountOptions,
     _In_opt_ LPCWSTR PackageFamilyName,
     _Out_ LPWSTR* InstalledDistributionName,
     _Out_ LXSS_ERROR_INFO* Error,
@@ -395,7 +397,7 @@ try
     RETURN_HR_IF(RPC_E_DISCONNECTED, !session);
 
     return session->RegisterDistribution(
-        DistributionName, Version, FileHandle, ErrorHandle, TargetDirectory, Flags, VhdSize, PackageFamilyName, InstalledDistributionName, pDistroGuid);
+        DistributionName, Version, FileHandle, ErrorHandle, TargetDirectory, Flags, VhdSize, FsType, FsMountOptions, PackageFamilyName, InstalledDistributionName, pDistroGuid);
 }
 CATCH_RETURN()
 
@@ -415,6 +417,8 @@ try
         TargetDirectory,
         0,
         0,
+        nullptr,
+        nullptr,
         packageFamilyName.empty() ? nullptr : packageFamilyName.c_str(),
         nullptr,
         nullptr,
@@ -430,6 +434,8 @@ HRESULT STDMETHODCALLTYPE LxssUserSession::RegisterDistributionPipe(
     _In_ LPCWSTR TargetDirectory,
     _In_ ULONG Flags,
     _In_ ULONG64 VhdSize,
+    _In_opt_ LPCWSTR FsType,
+    _In_opt_ LPCWSTR FsMountOptions,
     _In_opt_ LPCWSTR PackageFamilyName,
     _Out_ LPWSTR* InstalledDistributionName,
     _Out_ LXSS_ERROR_INFO* Error,
@@ -442,7 +448,7 @@ try
     RETURN_HR_IF(RPC_E_DISCONNECTED, !session);
 
     return session->RegisterDistribution(
-        DistributionName, Version, PipeHandle, ErrorHandle, TargetDirectory, Flags, VhdSize, PackageFamilyName, InstalledDistributionName, pDistroGuid);
+        DistributionName, Version, PipeHandle, ErrorHandle, TargetDirectory, Flags, VhdSize, FsType, FsMountOptions, PackageFamilyName, InstalledDistributionName, pDistroGuid);
 }
 CATCH_RETURN()
 
@@ -480,6 +486,18 @@ try
 }
 CATCH_RETURN()
 
+HRESULT STDMETHODCALLTYPE LxssUserSession::SetFsMountOptions(_In_ LPCGUID DistroGuid, _In_ LPCWSTR FsMountOptions, _Out_ LXSS_ERROR_INFO* Error)
+try
+{
+    ServiceExecutionContext context(Error);
+
+    const auto session = m_session.lock();
+    RETURN_HR_IF(RPC_E_DISCONNECTED, !session);
+
+    return session->SetFsMountOptions(DistroGuid, FsMountOptions);
+}
+CATCH_RETURN()
+
 HRESULT STDMETHODCALLTYPE LxssUserSession::ResizeDistribution(_In_ LPCGUID DistroGuid, _In_ HANDLE OutputHandle, _In_ ULONG64 NewSize, _Out_ LXSS_ERROR_INFO* Error)
 try
 {
@@ -1297,6 +1315,8 @@ LxssUserSessionImpl::ImportDistributionInplace(_In_ LPCWSTR DistributionName, _I
         LX_UID_ROOT,
         nullptr,
         path.filename().c_str(),
+        nullptr,
+        nullptr,
         false);
 
     auto configuration = s_GetDistributionConfiguration(registration);
@@ -1350,6 +1370,8 @@ HRESULT LxssUserSessionImpl::RegisterDistribution(
     _In_ LPCWSTR TargetDirectory,
     _In_ ULONG Flags,
     _In_ ULONG64 VhdSize,
+    _In_opt_ LPCWSTR FsType,
+    _In_opt_ LPCWSTR FsMountOptions,
     _In_opt_ LPCWSTR PackageFamilyName,
     _Out_opt_ LPWSTR* InstalledDistributionName,
     _Out_ GUID* pDistroGuid)
@@ -1488,6 +1510,8 @@ HRESULT LxssUserSessionImpl::RegisterDistribution(
                 LX_UID_ROOT,
                 PackageFamilyName,
                 vhdName.c_str(),
+                FsType,
+                FsMountOptions,
                 WI_IsFlagClear(Flags, LXSS_IMPORT_DISTRO_FLAGS_NO_OOBE));
 
             configuration = s_GetDistributionConfiguration(registration, DistributionName == nullptr);
@@ -1756,6 +1780,29 @@ try
 }
 CATCH_RETURN()
 
+HRESULT LxssUserSessionImpl::SetFsMountOptions(_In_ LPCGUID DistroGuid, _In_ LPCWSTR FsMountOptions)
+try
+{
+    ExecutionContext context(Context::ConfigureDistro);
+
+    WSL_LOG("SetFsMountOptions", TraceLoggingValue(FsMountOptions, "FsMountOptions"));
+
+    const wil::unique_hkey lxssKey = s_OpenLxssUserKey();
+    std::lock_guard lock(m_instanceLock);
+
+    // Ensure the distribution exists.
+    auto distribution = DistributionRegistration::Open(lxssKey.get(), *DistroGuid);
+
+    // Write the new mount options.
+    distribution.Write(Property::FsMountOptions, FsMountOptions);
+
+    // Terminate the distribution so the new settings will take effect.
+    _TerminateInstanceInternal(&distribution.Id(), false);
+
+    return S_OK;
+}
+CATCH_RETURN()
+
 HRESULT LxssUserSessionImpl::ResizeDistribution(_In_ LPCGUID DistroGuid, _In_ HANDLE OutputHandle, _In_ ULONG64 NewSize)
 try
 {
@@ -2432,7 +2479,7 @@ void LxssUserSessionImpl::_CreateLegacyRegistration(_In_ HKEY LxssKey, _In_ HAND
     const auto basePath = wsl::windows::common::filesystem::GetLegacyBasePath(UserToken);
 
     DistributionRegistration::Create(
-        LxssKey, LXSS_LEGACY_DISTRO_GUID, LXSS_LEGACY_INSTALL_NAME, LXSS_DISTRO_VERSION_LEGACY, basePath.c_str(), configFlags, defaultUid, nullptr, LXSS_VM_MODE_VHD_NAME, false);
+        LxssKey, LXSS_LEGACY_DISTRO_GUID, LXSS_LEGACY_INSTALL_NAME, LXSS_DISTRO_VERSION_LEGACY, basePath.c_str(), configFlags, defaultUid, nullptr, LXSS_VM_MODE_VHD_NAME, nullptr, nullptr, false);
 
     _SetDistributionInstalled(LxssKey, LXSS_LEGACY_DISTRO_GUID);
 }
@@ -3991,6 +4038,8 @@ LxssUserSessionImpl::s_GetDistributionConfiguration(const DistributionRegistrati
 
     // Read the vhd file name and append to the base path.
     configuration.VhdFilePath = configuration.BasePath / Distro.Read(Property::VhdFileName);
+    configuration.FsType = Distro.Read(Property::FsType);
+    configuration.FsMountOptions = Distro.Read(Property::FsMountOptions);
     configuration.Flags = Distro.Read(Property::Flags);
 
     configuration.OsVersion = Distro.Read(Property::OsVersion).value_or(L"");
diff --git a/src/windows/service/exe/LxssUserSession.h b/src/windows/service/exe/LxssUserSession.h
index 6e2d41687..4702d707b 100644
--- a/src/windows/service/exe/LxssUserSession.h
+++ b/src/windows/service/exe/LxssUserSession.h
@@ -164,6 +164,8 @@ class DECLSPEC_UUID("a9b7a1b9-0671-405c-95f1-e0612cb4ce7e") LxssUserSession
         _In_ LPCWSTR TargetDirectory,
         _In_ ULONG Flags,
         _In_ ULONG64 VhdSize,
+        _In_opt_ LPCWSTR FsType,
+        _In_opt_ LPCWSTR FsMountOptions,
         _In_opt_ LPCWSTR PackageFamilyName,
         _Out_ LPWSTR* InstalledDistributionName,
         _Out_ LXSS_ERROR_INFO* Error,
@@ -180,6 +182,8 @@ class DECLSPEC_UUID("a9b7a1b9-0671-405c-95f1-e0612cb4ce7e") LxssUserSession
         _In_ LPCWSTR TargetDirectory,
         _In_ ULONG Flags,
         _In_ ULONG64 VhdSize,
+        _In_opt_ LPCWSTR FsType,
+        _In_opt_ LPCWSTR FsMountOptions,
         _In_opt_ LPCWSTR PackageFamilyName,
         _Out_ LPWSTR* InstalledDistributionName,
         _Out_ LXSS_ERROR_INFO* Error,
@@ -200,6 +204,11 @@ class DECLSPEC_UUID("a9b7a1b9-0671-405c-95f1-e0612cb4ce7e") LxssUserSession
     /// </summary>
     IFACEMETHOD(SetSparse)(_In_ LPCGUID DistroGuid, _In_ BOOLEAN Sparse, _In_ BOOLEAN AllowUnsafe, _Out_ LXSS_ERROR_INFO* Error) override;
 
+    /// <summary>
+    /// Sets the filesystem mount options for a distribution.
+    /// </summary>
+    IFACEMETHOD(SetFsMountOptions)(_In_ LPCGUID DistroGuid, _In_ LPCWSTR FsMountOptions, _Out_ LXSS_ERROR_INFO* Error) override;
+
     /// <summary>
     /// Sets the version for a distribution.
     /// </summary>
@@ -457,6 +466,8 @@ class LxssUserSessionImpl
         _In_ LPCWSTR TargetDirectory,
         _In_ ULONG Flags,
         _In_ ULONG64 VhdSize,
+        _In_opt_ LPCWSTR FsType,
+        _In_opt_ LPCWSTR FsMountOptions,
         _In_opt_ LPCWSTR PackageFamilyName,
         _Out_opt_ LPWSTR* InstalledDistributionName,
         _Out_ GUID* pDistroGuid);
@@ -479,6 +490,12 @@ class LxssUserSessionImpl
     HRESULT
     SetSparse(_In_ LPCGUID DistroGuid, _In_ BOOLEAN Sparse, _In_ BOOLEAN AllowUnsafe);
 
+    /// <summary>
+    /// Sets the filesystem mount options for a distribution.
+    /// </summary>
+    HRESULT
+    SetFsMountOptions(_In_ LPCGUID DistroGuid, _In_ LPCWSTR FsMountOptions);
+
     /// <summary>
     /// Sets the version for a distribution.
     /// </summary>
diff --git a/src/windows/service/exe/WslCoreInstance.cpp b/src/windows/service/exe/WslCoreInstance.cpp
index 74fe3168d..7368b22ed 100644
--- a/src/windows/service/exe/WslCoreInstance.cpp
+++ b/src/windows/service/exe/WslCoreInstance.cpp
@@ -62,7 +62,7 @@ WslCoreInstance::WslCoreInstance(
         // N.B. EUCLEAN (117) can be returned if the disk's journal is corrupted.
         if ((result.Result == EINVAL || result.Result == 117) && result.FailureStep == LxInitCreateInstanceStepMountDisk)
         {
-            THROW_HR(WSL_E_DISK_CORRUPTED);
+            THROW_HR(WSL_E_MOUNT_FAILED);
         }
         else
         {
diff --git a/src/windows/service/exe/WslCoreVm.cpp b/src/windows/service/exe/WslCoreVm.cpp
index 39552dd9c..b8fd5fb43 100644
--- a/src/windows/service/exe/WslCoreVm.cpp
+++ b/src/windows/service/exe/WslCoreVm.cpp
@@ -1199,8 +1199,8 @@ std::shared_ptr<LxssRunningInstance> WslCoreVm::CreateInstance(
     message->MountDeviceType = LxMiniInitMountDeviceTypeLun;
     message->DeviceId = lun;
     message->Flags = flags;
-    message.WriteString(message->FsTypeOffset, "ext4");
-    message.WriteString(message->MountOptionsOffset, "discard,errors=remount-ro,data=ordered");
+    message.WriteString(message->FsTypeOffset, Configuration.FsType);
+    message.WriteString(message->MountOptionsOffset, Configuration.FsMountOptions);
     message.WriteString(message->VmIdOffset, m_machineId);
     message.WriteString(message->DistributionNameOffset, Configuration.Name);
     message.WriteString(message->SharedMemoryRootOffset, sharedMemoryRoot);
diff --git a/src/windows/service/inc/wslservice.idl b/src/windows/service/inc/wslservice.idl
index c68ad7567..c59b30b99 100644
--- a/src/windows/service/inc/wslservice.idl
+++ b/src/windows/service/inc/wslservice.idl
@@ -99,6 +99,12 @@ cpp_quote("#define LXSS_DISTRO_DEFAULT_ENVIRONMENT \"HOSTTYPE=x86_64\0LANG=en_US
 
 cpp_quote("#define LXSS_DISTRO_DEFAULT_KERNEL_COMMAND_LINE \"BOOT_IMAGE=/kernel init=/init\"")
 
+cpp_quote("#define LXSS_DISTRO_DEFAULT_FS_TYPE L\"ext4\"")
+cpp_quote("#define LXSS_DISTRO_DEFAULT_FS_MOUNT_OPTIONS_EXT4 L\"discard,errors=remount-ro,data=ordered\"")
+cpp_quote("#define LXSS_DISTRO_DEFAULT_FS_MOUNT_OPTIONS_BTRFS L\"discard\"")
+cpp_quote("#define LXSS_DISTRO_DEFAULT_FS_MOUNT_OPTIONS_XFS L\"discard\"")
+cpp_quote("#define LXSS_DISTRO_DEFAULT_FS_MOUNT_OPTIONS LXSS_DISTRO_DEFAULT_FS_MOUNT_OPTIONS_EXT4")
+
 cpp_quote("#define LXSS_DISTRO_FLAGS_ENABLE_INTEROP 0x1")
 cpp_quote("#define LXSS_DISTRO_FLAGS_APPEND_NT_PATH 0x2")
 cpp_quote("#define LXSS_DISTRO_FLAGS_ENABLE_DRIVE_MOUNTING 0x4")
@@ -138,7 +144,7 @@ cpp_quote("#define LXSS_PLAN9_UNIX_SOCKET L\"fsserver\"")
 
 cpp_quote("#define LXSS_VM_MODE_INITRD_NAME L\"initrd.img\"")
 cpp_quote("#define LXSS_VM_MODE_KERNEL_NAME L\"kernel\"")
-cpp_quote("#define LXSS_VM_MODE_VHD_NAME L\"ext4.vhdx\"")
+cpp_quote("#define LXSS_VM_MODE_VHD_NAME L\"distro.vhdx\"")
 
 cpp_quote("#define LXSS_TOOLS_DIRECTORY L\"tools\"")
 
@@ -187,6 +193,8 @@ interface ILxssUserSession : IUnknown
         [in, unique] LPCWSTR TargetDirectory,
         [in] ULONG Flags,
         [in] ULONG64 VhdSize,
+        [in, unique] LPCWSTR FsType,
+        [in, unique] LPCWSTR FsMountOptions,
         [in, unique] LPCWSTR PackageFamilyName,
         [out] LPWSTR* InstalledDistributionName,
         [in, out] LXSS_ERROR_INFO* Error,
@@ -201,6 +209,8 @@ interface ILxssUserSession : IUnknown
         [in, unique] LPCWSTR TargetDirectory,
         [in] ULONG Flags,
         [in] ULONG64 VhdSize,
+        [in, unique] LPCWSTR FsType,
+        [in, unique] LPCWSTR FsMountOptions,
         [in, unique] LPCWSTR PackageFamilyName,
         [out] LPWSTR* InstalledDistributionName,
         [in, out] LXSS_ERROR_INFO* Error,
@@ -343,6 +353,11 @@ interface ILxssUserSession : IUnknown
         [in] LPCGUID DistroGuid,
         [in] LPCWSTR DistributionName, 
         [ in, out ] LXSS_ERROR_INFO * Error);
+
+    HRESULT SetFsMountOptions(
+        [in] LPCGUID DistroGuid,
+        [in] LPCWSTR FsMountOptions,
+        [in, out] LXSS_ERROR_INFO* Error);
 };
 
 
@@ -390,7 +405,7 @@ cpp_quote("#define WSL_E_DISK_MOUNT_DISABLED MAKE_HRESULT(SEVERITY_ERROR, FACILI
 cpp_quote("#define WSL_E_WSL1_DISABLED MAKE_HRESULT(SEVERITY_ERROR, FACILITY_ITF, WSL_E_BASE + 0x2C) /* 0x8004032C */")
 cpp_quote("#define WSL_E_VIRTUAL_MACHINE_PLATFORM_REQUIRED MAKE_HRESULT(SEVERITY_ERROR, FACILITY_ITF, WSL_E_BASE + 0x2D) /* 0x8004032D */")
 cpp_quote("#define WSL_E_LOCAL_SYSTEM_NOT_SUPPORTED MAKE_HRESULT(SEVERITY_ERROR, FACILITY_ITF, WSL_E_BASE + 0x2E) /* 0x8004032E */")
-cpp_quote("#define WSL_E_DISK_CORRUPTED MAKE_HRESULT(SEVERITY_ERROR, FACILITY_ITF, WSL_E_BASE + 0x2F) /* 0x8004032F */")
+cpp_quote("#define WSL_E_MOUNT_FAILED MAKE_HRESULT(SEVERITY_ERROR, FACILITY_ITF, WSL_E_BASE + 0x2F) /* 0x8004032F */")
 cpp_quote("#define WSL_E_DISTRIBUTION_NAME_NEEDED MAKE_HRESULT(SEVERITY_ERROR, FACILITY_ITF, WSL_E_BASE + 0x30) /* 0x80040330 */")
 cpp_quote("#define WSL_E_INVALID_JSON MAKE_HRESULT(SEVERITY_ERROR, FACILITY_ITF, WSL_E_BASE + 0x31) /* 0x80040331 */")
 cpp_quote("#define WSL_E_VM_CRASHED MAKE_HRESULT(SEVERITY_ERROR, FACILITY_ITF, WSL_E_BASE + 0x32) /* 0x80040332 */")
diff --git a/test/windows/UnitTests.cpp b/test/windows/UnitTests.cpp
index 8d5e6b39f..72df4a9ab 100644
--- a/test/windows/UnitTests.cpp
+++ b/test/windows/UnitTests.cpp
@@ -981,7 +981,7 @@ class UnitTests
     {
         const auto tarFileName = LXSST_IMPORT_DISTRO_TEST_DIR L"test.tar";
         const auto rootfsDirectoryName = LXSST_IMPORT_DISTRO_TEST_DIR L"rootfs";
-        const auto vhdFileName = LXSST_IMPORT_DISTRO_TEST_DIR L"ext4.vhdx";
+        const auto vhdFileName = LXSST_IMPORT_DISTRO_TEST_DIR L"distro.vhdx";
         auto cleanup = wil::scope_exit([&] {
             try
             {
@@ -1084,6 +1084,146 @@ class UnitTests
         VERIFY_ARE_EQUAL(err, L"bsdtar: Error opening archive: Unrecognized archive format\n");
     }
 
+    TEST_METHOD(ImportDistroWithFsType)
+    {
+        WSL2_TEST_ONLY();
+
+        //
+        // Test importing a distribution with custom filesystem type.
+        // Validates ext4, btrfs, and xfs filesystem types.
+        //
+
+        auto validateOutput = [](LPCWSTR commandLine, LPCWSTR expectedOutput, DWORD expectedExitCode = 0) {
+            auto [out, err] = LxsstuLaunchWslAndCaptureOutput(commandLine, expectedExitCode);
+            VERIFY_ARE_EQUAL(expectedOutput, out);
+        };
+
+        auto testFsType = [&](LPCWSTR fsType, LPCWSTR expectedFsType) {
+            const auto distroName = std::format(L"fstype-test-{}", fsType);
+
+            auto cleanup = wil::scope_exit_log(WI_DIAGNOSTICS_INFO, [&]() {
+                LxsstuLaunchWsl(std::format(L"--unregister {}", distroName));
+                std::filesystem::remove_all(LXSST_IMPORT_DISTRO_TEST_DIR);
+            });
+
+            // Import with custom fs type
+            validateOutput(
+                std::format(L"--import {} {} \"{}\" --version 2 --fs-type {}", distroName, LXSST_IMPORT_DISTRO_TEST_DIR, g_testDistroPath, fsType).c_str(),
+                L"The operation completed successfully. \r\n",
+                0);
+
+            // Verify the filesystem type is correct by checking /etc/fstab or mount output
+            auto [mountOut, _] = LxsstuLaunchWslAndCaptureOutput(std::format(L"-d {} -- mount | grep ' / '", distroName));
+            VERIFY_IS_TRUE(mountOut.find(expectedFsType) != std::wstring::npos);
+
+            // Cleanup
+            WslShutdown();
+        };
+
+        // Test ext4 (default)
+        testFsType(L"ext4", L"ext4");
+
+        // Test btrfs
+        testFsType(L"btrfs", L"btrfs");
+
+        // Test xfs
+        testFsType(L"xfs", L"xfs");
+    }
+
+    TEST_METHOD(ImportDistroWithFsMountOptions)
+    {
+        WSL2_TEST_ONLY();
+
+        //
+        // Test importing a distribution with custom filesystem mount options.
+        // Covers ext4, btrfs (with subvol), and xfs filesystem types.
+        //
+
+        auto importAndValidate = [&](LPCWSTR testName, const std::wstring& extraArgs, const std::vector<std::wstring>& expectedStrings) {
+            const auto distroName = std::format(L"fsmount-test-{}", testName);
+
+            auto cleanup = wil::scope_exit_log(WI_DIAGNOSTICS_INFO, [&]() {
+                LxsstuLaunchWsl(std::format(L"--unregister {}", distroName));
+                std::filesystem::remove_all(LXSST_IMPORT_DISTRO_TEST_DIR);
+            });
+
+            auto [out, err] = LxsstuLaunchWslAndCaptureOutput(
+                std::format(L"--import {} {} \"{}\" --version 2 {}", distroName, LXSST_IMPORT_DISTRO_TEST_DIR, g_testDistroPath, extraArgs),
+                0);
+            VERIFY_ARE_EQUAL(out, L"The operation completed successfully. \r\n");
+
+            auto [mountOut, _] = LxsstuLaunchWslAndCaptureOutput(std::format(L"-d {} -- mount | grep ' / '", distroName));
+            for (const auto& expected : expectedStrings)
+            {
+                VERIFY_IS_TRUE(mountOut.find(expected) != std::wstring::npos);
+            }
+
+            WslShutdown();
+        };
+
+        // Test ext4 with kernel mount options
+        importAndValidate(L"ext4", L"--fs-mount-options discard,data=writeback", {L"ext4", L"data=writeback"});
+
+        // Test btrfs with compress, subvol, and ssd options
+        importAndValidate(L"btrfs", L"--fs-type btrfs --fs-mount-options compress=zstd,subvol=@,ssd",
+            {L"btrfs", L"compress=zstd", L"subvol=/@", L"ssd"});
+
+        // Test xfs with quota options (uquota/gquota are displayed as usrquota/grpquota by mount)
+        importAndValidate(L"xfs", L"--fs-type xfs --fs-mount-options uquota,gquota",
+            {L"xfs", L"usrquota", L"grpquota"});
+    }
+
+    TEST_METHOD(ManageSetFsMountOptions)
+    {
+        WSL2_TEST_ONLY();
+
+        //
+        // Test the --manage --set-fs-mount-options command across different filesystem types.
+        //
+
+        auto testManageMountOptions = [&](LPCWSTR testName, const std::wstring& importExtraArgs,
+            const std::wstring& mountOptions, const std::vector<std::wstring>& expectedStrings) {
+            const auto distroName = std::format(L"manage-fsmount-{}", testName);
+
+            auto cleanup = wil::scope_exit_log(WI_DIAGNOSTICS_INFO, [&]() {
+                LxsstuLaunchWsl(std::format(L"--unregister {}", distroName));
+                std::filesystem::remove_all(LXSST_IMPORT_DISTRO_TEST_DIR);
+            });
+
+            // Import a distribution
+            auto [out, err] = LxsstuLaunchWslAndCaptureOutput(
+                std::format(L"--import {} {} \"{}\" --version 2 {}", distroName, LXSST_IMPORT_DISTRO_TEST_DIR, g_testDistroPath, importExtraArgs),
+                0);
+            VERIFY_ARE_EQUAL(out, L"The operation completed successfully. \r\n");
+
+            // Set the mount options using --manage
+            WslShutdown();
+            std::tie(out, err) = LxsstuLaunchWslAndCaptureOutput(
+                std::format(L"--manage {} --set-fs-mount-options {}", distroName, mountOptions),
+                0);
+            VERIFY_ARE_EQUAL(out, L"The operation completed successfully. \r\n");
+
+            // Verify the mount options are applied after restart
+            auto [mountOut, _] = LxsstuLaunchWslAndCaptureOutput(std::format(L"-d {} -- mount | grep ' / '", distroName));
+            for (const auto& expected : expectedStrings)
+            {
+                VERIFY_IS_TRUE(mountOut.find(expected) != std::wstring::npos);
+            }
+
+            WslShutdown();
+        };
+
+        // Test changing data options on ext4
+        testManageMountOptions(L"ext4", L"--fs-type ext4", L"data=journal", {L"ext4", L"data=journal"});
+
+        // Test changing compress option on btrfs
+        testManageMountOptions(L"btrfs", L"--fs-type btrfs", L"compress=lzo", {L"btrfs", L"compress=lzo"});
+
+        // Test enabling quotas on xfs
+        testManageMountOptions(L"xfs", L"--fs-type xfs", L"uquota,gquota", {L"xfs", L"usrquota", L"grpquota"});
+    }
+
+
     TEST_METHOD(AppxDistroDeletion)
     {
         // Create a dummy distro registration
@@ -1102,7 +1242,7 @@ class UnitTests
         wsl::windows::common::registry::WriteDword(key.get(), nullptr, L"Flags", LXSS_DISTRO_FLAGS_VM_MODE);
 
         // Create a dummy vhd
-        const auto vhdPath = vhdDir.string() + "\\ext4.vhdx";
+        const auto vhdPath = vhdDir.string() + "\\distro.vhdx";
 
         wil::unique_handle vhdHandle(CreateFileA(vhdPath.c_str(), GENERIC_READ, 0, nullptr, CREATE_ALWAYS, 0, nullptr));
         VERIFY_IS_TRUE(vhdHandle.is_valid());
@@ -1284,7 +1424,7 @@ class UnitTests
 
                 ValidateErrorMessage(
                     L"-d DummyBrokenDistro",
-                    L"Failed to attach disk 'C:\\DoesNotExit\\ext4.vhdx' to WSL2: The system cannot find the path "
+                    L"Failed to attach disk 'C:\\DoesNotExit\\distro.vhdx' to WSL2: The system cannot find the path "
                     L"specified. ",
                     L"Wsl/Service/CreateInstance/MountDisk/HCS/ERROR_PATH_NOT_FOUND");
 
@@ -1353,6 +1493,11 @@ class UnitTests
 
         ValidateErrorMessage(L"--manage test_distro --resize foo", L"Invalid size: foo", L"Wsl/E_INVALIDARG");
 
+        ValidateErrorMessage(
+            L"--manage DoesNotExist --set-fs-mount-options discard",
+            L"There is no distribution with the supplied name.",
+            L"Wsl/Service/WSL_E_DISTRO_NOT_FOUND");
+
         ValidateErrorMessage(
             L"--install --distribution debian --no-distribution",
             L"Arguments --no-distribution and --distribution can't be specified at same time.",
@@ -1540,6 +1685,13 @@ Arguments for managing Windows Subsystem for Linux:
             --from-file <Path>
                 Install a distribution from a local file.
 
+            --fs-type <FsType>
+                Specify the filesystem type to use for the distribution root.
+                Defaults to ext4.
+
+            --fs-mount-options <Options>
+                Specify additional mount options for the filesystem.
+
             --legacy
                 Use the legacy distribution manifest.
 
@@ -1580,6 +1732,9 @@ Arguments for managing Windows Subsystem for Linux:
             --resize <MemoryString>
                 Resize the disk of the distribution to the specified size.
 
+            --set-fs-mount-options <Options>
+                Set the filesystem mount options for the distribution root.
+
     --mount <Disk>
         Attaches and mounts a physical or virtual disk in all WSL 2 distributions.
 
@@ -1655,6 +1810,13 @@ Arguments for managing distributions in Windows Subsystem for Linux:
                 Specifies that the provided file is a .vhd or .vhdx file, not a tar file.
                 This operation makes a copy of the VHD file at the specified install location.
 
+            --fs-type <FsType>
+                Specify the filesystem type to use for the distribution root.
+                Defaults to ext4.
+
+            --fs-mount-options <Options>
+                Specify additional mount options for the filesystem.
+
     --import-in-place <Distro> <FileName>
         Imports the specified VHD file as a new distribution.
         This virtual hard disk must be formatted with the ext4 filesystem type.
@@ -2424,14 +2586,14 @@ Error code: Wsl/InstallDistro/WSL_E_DISTRO_NOT_FOUND
             // Validate that starting the distribution fails with the correct error code.
             validateOutput(
                 L"-d BrokenDistro echo ok",
-                L"The distribution failed to start because its virtual disk is corrupted.\r\n"
-                L"Error code: Wsl/Service/CreateInstance/WSL_E_DISK_CORRUPTED\r\n");
+                L"The distribution failed to start because its virtual disk is corrupted, has an unexpected filesystem type, or has invalid mount options.\r\n"
+                L"Error code: Wsl/Service/CreateInstance/WSL_E_MOUNT_FAILED\r\n");
 
             // Validate that trying to export the distribution fails with the correct error code.
             validateOutput(
                 L"--export BrokenDistro dummy.tar",
-                L"The distribution failed to start because its virtual disk is corrupted.\r\n"
-                L"Error code: Wsl/Service/WSL_E_DISK_CORRUPTED\r\n");
+                L"The distribution failed to start because its virtual disk is corrupted, has an unexpected filesystem type, or has invalid mount options.\r\n"
+                L"Error code: Wsl/Service/WSL_E_MOUNT_FAILED\r\n");
 
             // Shutdown WSL to force the disk to detach.
             VERIFY_ARE_EQUAL(LxsstuLaunchWsl(L"--shutdown"), 0L);
@@ -2440,8 +2602,8 @@ Error code: Wsl/InstallDistro/WSL_E_DISTRO_NOT_FOUND
         // Import a corrupted vhd.
         validateOutput(
             std::format(L"--import-in-place test-distro-corrupted \"{}\"", vhdPath.wstring()),
-            L"The distribution failed to start because its virtual disk is corrupted.\r\n"
-            L"Error code: Wsl/Service/RegisterDistro/WSL_E_DISK_CORRUPTED\r\n");
+            L"The distribution failed to start because its virtual disk is corrupted, has an unexpected filesystem type, or has invalid mount options.\r\n"
+            L"Error code: Wsl/Service/RegisterDistro/WSL_E_MOUNT_FAILED\r\n");
 
         // Ensure the VHD can be deleted to make sure it was properly ejected from the VM.
         VERIFY_ARE_EQUAL(DeleteFileW(vhdPath.c_str()), TRUE);
@@ -2828,7 +2990,7 @@ Error code: Wsl/InstallDistro/WSL_E_DISTRO_NOT_FOUND
 
             // Validate that the distribution still starts
             validateDistro();
-            VERIFY_IS_TRUE(std::filesystem::exists(std::format(L"{}\\ext4.vhdx", testFolder)));
+            VERIFY_IS_TRUE(std::filesystem::exists(std::format(L"{}\\distro.vhdx", testFolder)));
         }
 
         auto absolutePath = std::filesystem::weakly_canonical(".").wstring();
@@ -2840,7 +3002,7 @@ Error code: Wsl/InstallDistro/WSL_E_DISTRO_NOT_FOUND
 
             // Validate that the distribution still starts
             validateDistro();
-            VERIFY_IS_TRUE(std::filesystem::exists(std::format(L"{}\\ext4.vhdx", absolutePath)));
+            VERIFY_IS_TRUE(std::filesystem::exists(std::format(L"{}\\distro.vhdx", absolutePath)));
         }
 
         // Try to move the distribution to a folder that's already in use
@@ -2858,7 +3020,7 @@ Error code: Wsl/InstallDistro/WSL_E_DISTRO_NOT_FOUND
                 L"Wsl/Service/MoveDistro/ERROR_FILE_EXISTS\r\n");
             // Validate that the distribution still starts and that the vhd hasn't moved.
             validateDistro();
-            VERIFY_IS_TRUE(std::filesystem::exists(std::format(L"{}\\ext4.vhdx", absolutePath)));
+            VERIFY_IS_TRUE(std::filesystem::exists(std::format(L"{}\\distro.vhdx", absolutePath)));
         }
 
         // Try to move the distribution to an invalid path
@@ -2873,7 +3035,7 @@ Error code: Wsl/InstallDistro/WSL_E_DISTRO_NOT_FOUND
                 L"Wsl/Service/MoveDistro/ERROR_INVALID_NAME\r\n");
             // Validate that the distribution still starts and that the vhd hasn't moved.
             validateDistro();
-            VERIFY_IS_TRUE(std::filesystem::exists(std::format(L"{}\\ext4.vhdx", absolutePath)));
+            VERIFY_IS_TRUE(std::filesystem::exists(std::format(L"{}\\distro.vhdx", absolutePath)));
         }
     }
 
@@ -3028,8 +3190,8 @@ Error code: Wsl/InstallDistro/WSL_E_DISTRO_NOT_FOUND
 
             // std::pair[0] = Written value, std::pair[1] = Actual/Expected value
             static const std::vector<std::pair<PCWSTR, PCWSTR>> filePathsToTest{
-                {L"C:\\DoesNotExit\\ext4.vhdx", L"C:\\DoesNotExit\\ext4.vhdx"},
-                {L"\\DoesNotExit\\ext4.vhdx", L"\\DoesNotExit\\ext4.vhdx"},
+                {L"C:\\DoesNotExit\\distro.vhdx", L"C:\\DoesNotExit\\distro.vhdx"},
+                {L"\\DoesNotExit\\distro.vhdx", L"\\DoesNotExit\\distro.vhdx"},
                 {L"", L""},
             };
 
@@ -3050,7 +3212,7 @@ Error code: Wsl/InstallDistro/WSL_E_DISTRO_NOT_FOUND
                         {L"", L""},
                         {L"notaport", L""},
                         {L"-5555", L""},
-                        {L"C:\\DoesNotExit\\ext4.vhdx", L""},
+                        {L"C:\\DoesNotExit\\distro.vhdx", L""},
                     },
                 },
                 {