private CreateHardLinkResult CreateHardLinkWin(AbsolutePath sourceFileName, AbsolutePath destinationFileName, bool replaceExisting)
{
SafeFileHandle sourceFileHandle = NativeMethods.CreateFile(
sourceFileName.Path,
0,
/* Do not need to request any particular access to modify link info */ FileShare.ReadWrite | FileShare.Delete,
IntPtr.Zero,
FileMode.Open,
0 /* Allow symbolic links to redirect us */,
IntPtr.Zero);
using (sourceFileHandle)
{
if (sourceFileHandle.IsInvalid)
{
switch (Marshal.GetLastWin32Error())
{
case NativeMethods.ERROR_FILE_NOT_FOUND:
case NativeMethods.ERROR_PATH_NOT_FOUND:
return(CreateHardLinkResult.FailedSourceDoesNotExist);
case NativeMethods.ERROR_ACCESS_DENIED:
return(CreateHardLinkResult.FailedSourceAccessDenied);
default:
return(CreateHardLinkResult.FailedSourceHandleInvalid);
}
}
if (destinationFileName.Length >= FileSystemConstants.MaxPath)
{
return(CreateHardLinkResult.FailedPathTooLong);
}
const string DosToNtPathPrefix = @"\??\";
// NtSetInformationFile always expects a special prefix even for short paths.
string path = DosToNtPathPrefix + destinationFileName.GetPathWithoutLongPathPrefix();
var linkInfo = new NativeMethods.FileLinkInformation(path, replaceExisting);
NativeMethods.NtStatus status = setLink(sourceFileHandle, linkInfo);
if (status.StatusCodeUint == (uint)NativeMethods.NtStatusCode.StatusAccessDenied)
{
// Access denied status can be returned by two reasons:
// 1. Something went wrong with the source path
// 2. Something went wrong with the destination path.
var retry = false;
// For case 1: we'll make sure that the source file allows attribute writes.
if (!FileUtilities.HasWritableAttributeAccessControl(sourceFileName.Path))
{
AllowAttributeWrites(sourceFileName);
retry = true;
}
// For case 2: we'll check the destination's file attribute
// and if the file has readonly attributes, then we'll remove them and will try to create hardlink one more time.
if (this.TryGetFileAttributes(destinationFileName, out var attributes) && (attributes & FileAttributes.ReadOnly) != 0)
{
SetFileAttributes(destinationFileName, FileAttributes.Normal);
retry = true;
}
if (retry)
{
status = setLink(sourceFileHandle, linkInfo);
}
}
if (status.Failed)
{
switch (status.StatusCodeUint)
{
case (uint)NativeMethods.NtStatusCode.StatusTooManyLinks:
return(CreateHardLinkResult.FailedMaxHardLinkLimitReached);
case (uint)NativeMethods.NtStatusCode.StatusObjectNameCollision:
return(CreateHardLinkResult.FailedDestinationExists);
case (uint)NativeMethods.NtStatusCode.StatusNotSameDevice:
return(CreateHardLinkResult.FailedSourceAndDestinationOnDifferentVolumes);
case (uint)NativeMethods.NtStatusCode.StatusAccessDenied:
return(CreateHardLinkResult.FailedAccessDenied);
case (uint)NativeMethods.NtStatusCode.StatusNotSupported:
return(CreateHardLinkResult.FailedNotSupported);
case (uint)NativeMethods.NtStatusCode.StatusObjectPathNotFound:
return(CreateHardLinkResult.FailedDestinationDirectoryDoesNotExist);
default:
throw new NTStatusException(status.StatusCodeUint, status.StatusName, string.Format(
CultureInfo.InvariantCulture,
"Unable to create hard link at '{0}', pointing to existing file '{1}' with NTSTATUS:[0x{2:X}] = [{3}]",
destinationFileName,
sourceFileName,
status.StatusCodeUint,
status.StatusName));
}
}
return(CreateHardLinkResult.Success);
}
private CreateHardLinkResult CreateHardLinkWin(AbsolutePath sourceFileName, AbsolutePath destinationFileName, bool replaceExisting)
{
SafeFileHandle sourceFileHandle = NativeMethods.CreateFile(
sourceFileName.Path,
0,
/* Do not need to request any particular access to modify link info */ FileShare.ReadWrite | FileShare.Delete,
IntPtr.Zero,
FileMode.Open,
0 /* Allow symbolic links to redirect us */,
IntPtr.Zero);
using (sourceFileHandle)
{
if (sourceFileHandle.IsInvalid)
{
switch (Marshal.GetLastWin32Error())
{
case NativeMethods.ERROR_FILE_NOT_FOUND:
case NativeMethods.ERROR_PATH_NOT_FOUND:
return(CreateHardLinkResult.FailedSourceDoesNotExist);
case NativeMethods.ERROR_ACCESS_DENIED:
return(CreateHardLinkResult.FailedSourceAccessDenied);
default:
return(CreateHardLinkResult.FailedSourceHandleInvalid);
}
}
if (destinationFileName.Length >= FileSystemConstants.MaxPath)
{
return(CreateHardLinkResult.FailedPathTooLong);
}
const string DosToNtPathPrefix = @"\??\";
// NtSetInformationFile always expects a special prefix even for short paths.
string path = DosToNtPathPrefix + destinationFileName.GetPathWithoutLongPathPrefix();
var linkInfo = new NativeMethods.FileLinkInformation(path, replaceExisting);
NativeMethods.NtStatus status = setLink(sourceFileHandle, linkInfo);
if (status.StatusCodeUint == (uint)NativeMethods.NtStatusCode.StatusAccessDenied)
{
if ((GetFileAttributes(destinationFileName) & FileAttributes.ReadOnly) != 0)
{
SetFileAttributes(destinationFileName, FileAttributes.Normal);
status = setLink(sourceFileHandle, linkInfo);
}
}
if (status.Failed)
{
switch (status.StatusCodeUint)
{
case (uint)NativeMethods.NtStatusCode.StatusTooManyLinks:
return(CreateHardLinkResult.FailedMaxHardLinkLimitReached);
case (uint)NativeMethods.NtStatusCode.StatusObjectNameCollision:
return(CreateHardLinkResult.FailedDestinationExists);
case (uint)NativeMethods.NtStatusCode.StatusNotSameDevice:
return(CreateHardLinkResult.FailedSourceAndDestinationOnDifferentVolumes);
case (uint)NativeMethods.NtStatusCode.StatusAccessDenied:
return(CreateHardLinkResult.FailedAccessDenied);
case (uint)NativeMethods.NtStatusCode.StatusNotSupported:
return(CreateHardLinkResult.FailedNotSupported);
case (uint)NativeMethods.NtStatusCode.StatusObjectPathNotFound:
return(CreateHardLinkResult.FailedDestinationDirectoryDoesNotExist);
default:
throw new NTStatusException(status.StatusCodeUint, status.StatusName, string.Format(
CultureInfo.InvariantCulture,
"Unable to create hard link at '{0}', pointing to existing file '{1}' with NTSTATUS:[0x{2:X}] = [{3}]",
destinationFileName,
sourceFileName,
status.StatusCodeUint,
status.StatusName));
}
}
return(CreateHardLinkResult.Success);
}
NativeMethods.NtStatus setLink(SafeFileHandle handle, NativeMethods.FileLinkInformation linkInfo)
{
return(NativeMethods.NtSetInformationFile(
handle,
out _,
linkInfo,
(uint)Marshal.SizeOf(linkInfo),
NativeMethods.FileInformationClass.FileLinkInformation));
}
}