Move graphdrivers into runtime top level pkg

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)

runtime/graphdriver/devmapper/ioctl.go

@@ -0,0 +1,71 @@
+// +build linux,amd64
+
+package devmapper
+
+import (
+	"unsafe"
+)
+
+func ioctlLoopCtlGetFree(fd uintptr) (int, error) {
+	index, _, err := sysSyscall(sysSysIoctl, fd, LoopCtlGetFree, 0)
+	if err != 0 {
+		return 0, err
+	}
+	return int(index), nil
+}
+
+func ioctlLoopSetFd(loopFd, sparseFd uintptr) error {
+	if _, _, err := sysSyscall(sysSysIoctl, loopFd, LoopSetFd, sparseFd); err != 0 {
+		return err
+	}
+	return nil
+}
+
+func ioctlLoopSetStatus64(loopFd uintptr, loopInfo *LoopInfo64) error {
+	if _, _, err := sysSyscall(sysSysIoctl, loopFd, LoopSetStatus64, uintptr(unsafe.Pointer(loopInfo))); err != 0 {
+		return err
+	}
+	return nil
+}
+
+func ioctlLoopClrFd(loopFd uintptr) error {
+	if _, _, err := sysSyscall(sysSysIoctl, loopFd, LoopClrFd, 0); err != 0 {
+		return err
+	}
+	return nil
+}
+
+func ioctlLoopGetStatus64(loopFd uintptr) (*LoopInfo64, error) {
+	loopInfo := &LoopInfo64{}
+
+	if _, _, err := sysSyscall(sysSysIoctl, loopFd, LoopGetStatus64, uintptr(unsafe.Pointer(loopInfo))); err != 0 {
+		return nil, err
+	}
+	return loopInfo, nil
+}
+
+func ioctlLoopSetCapacity(loopFd uintptr, value int) error {
+	if _, _, err := sysSyscall(sysSysIoctl, loopFd, LoopSetCapacity, uintptr(value)); err != 0 {
+		return err
+	}
+	return nil
+}
+
+func ioctlBlkGetSize64(fd uintptr) (int64, error) {
+	var size int64
+	if _, _, err := sysSyscall(sysSysIoctl, fd, BlkGetSize64, uintptr(unsafe.Pointer(&size))); err != 0 {
+		return 0, err
+	}
+	return size, nil
+}
+
+func ioctlBlkDiscard(fd uintptr, offset, length uint64) error {
+	var r [2]uint64
+	r[0] = offset
+	r[1] = length
+
+	if _, _, err := sysSyscall(sysSysIoctl, fd, BlkDiscard, uintptr(unsafe.Pointer(&r[0]))); err != 0 {
+		return err
+	}
+	return nil
+}