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Merge pull request #347 from kolyshkin/19.03-loopback-idx

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[19.03 backport] Use correct `LOOP_CTL_GET_FREE` API in `pkg/loopback`
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Sebastiaan van Stijn 2019-09-07 01:20:09 +02:00 • committed by GitHub
commit 81fcfc67cd
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1 changed files with 7 additions and 3 deletions
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10
pkg/loopback/ioctl.go
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@ -9,11 +9,15 @@ import (
)
func ioctlLoopCtlGetFree(fd uintptr) (int, error) {
index, err := unix.IoctlGetInt(int(fd), LoopCtlGetFree)
if err != nil {
// 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 index, nil
return int(ioctlReturn), nil
}
func ioctlLoopSetFd(loopFd, sparseFd uintptr) error {