moby/pkg/loopback/ioctl.go
Sebastiaan van Stijn a1150245cc
Update to Go 1.17.0, and gofmt with Go 1.17
Movified from 686be57d0a, and re-ran
gofmt again to address for files not present in 20.10 and vice-versa.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 686be57d0a)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2022-04-07 23:27:50 +02:00

53 lines
1.5 KiB
Go

//go:build linux
// +build linux
package loopback // import "github.com/docker/docker/pkg/loopback"
import (
"unsafe"
"golang.org/x/sys/unix"
)
func ioctlLoopCtlGetFree(fd uintptr) (int, error) {
// The ioctl interface for /dev/loop-control (since Linux 3.1) is a bit
// off compared to what you'd expect: instead of writing an integer to a
// parameter pointer like unix.IoctlGetInt() expects, it returns the first
// available loop device index directly.
ioctlReturn, _, err := unix.Syscall(unix.SYS_IOCTL, fd, LoopCtlGetFree, 0)
if err != 0 {
return 0, err
}
return int(ioctlReturn), nil
}
func ioctlLoopSetFd(loopFd, sparseFd uintptr) error {
return unix.IoctlSetInt(int(loopFd), unix.LOOP_SET_FD, int(sparseFd))
}
func ioctlLoopSetStatus64(loopFd uintptr, loopInfo *unix.LoopInfo64) error {
if _, _, err := unix.Syscall(unix.SYS_IOCTL, loopFd, unix.LOOP_SET_STATUS64, uintptr(unsafe.Pointer(loopInfo))); err != 0 {
return err
}
return nil
}
func ioctlLoopClrFd(loopFd uintptr) error {
if _, _, err := unix.Syscall(unix.SYS_IOCTL, loopFd, unix.LOOP_CLR_FD, 0); err != 0 {
return err
}
return nil
}
func ioctlLoopGetStatus64(loopFd uintptr) (*unix.LoopInfo64, error) {
loopInfo := &unix.LoopInfo64{}
if _, _, err := unix.Syscall(unix.SYS_IOCTL, loopFd, unix.LOOP_GET_STATUS64, uintptr(unsafe.Pointer(loopInfo))); err != 0 {
return nil, err
}
return loopInfo, nil
}
func ioctlLoopSetCapacity(loopFd uintptr, value int) error {
return unix.IoctlSetInt(int(loopFd), unix.LOOP_SET_CAPACITY, value)
}