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//go:build linux
package reflink
import (
"errors"
"os"
"golang.org/x/sys/unix"
)
// reflinkInternal performs the actual reflink action without worrying about fallback
func reflinkInternal(d, s *os.File) error {
ss, err := s.SyscallConn()
if err != nil {
return err
}
sd, err := d.SyscallConn()
if err != nil {
return err
}
var err2, err3 error
err = sd.Control(func(dfd uintptr) {
err2 = ss.Control(func(sfd uintptr) {
// int ioctl(int dest_fd, FICLONE, int src_fd);
err3 = unix.IoctlFileClone(int(dfd), int(sfd))
})
})
if err != nil {
// sd.Control failed
return err
}
if err2 != nil {
// ss.Control failed
return err2
}
if err3 != nil && errors.Is(err3, unix.ENOTSUP) {
return ErrReflinkFailed
}
// err3 is ioctl() response
return err3
}
func reflinkRangeInternal(dst, src *os.File, dstOffset, srcOffset, n int64) error {
ss, err := src.SyscallConn()
if err != nil {
return err
}
sd, err := dst.SyscallConn()
if err != nil {
return err
}
var err2, err3 error
err = sd.Control(func(dfd uintptr) {
err2 = ss.Control(func(sfd uintptr) {
req := &unix.FileCloneRange{
Src_fd: int64(sfd),
Src_offset: uint64(srcOffset),
Src_length: uint64(n),
Dest_offset: uint64(dstOffset),
}
// int ioctl(int dest_fd, FICLONE, int src_fd);
err3 = unix.IoctlFileCloneRange(int(dfd), req)
})
})
if err != nil {
// sd.Control failed
return err
}
if err2 != nil {
// ss.Control failed
return err2
}
if err3 != nil && errors.Is(err3, unix.ENOTSUP) {
return ErrReflinkFailed
}
// err3 is ioctl() response
return err3
}
func copyFileRange(dst, src *os.File, dstOffset, srcOffset, n int64) (int64, error) {
ss, err := src.SyscallConn()
if err != nil {
return 0, err
}
sd, err := dst.SyscallConn()
if err != nil {
return 0, err
}
var resN int
var err2, err3 error
err = sd.Control(func(dfd uintptr) {
err2 = ss.Control(func(sfd uintptr) {
// call syscall
resN, err3 = unix.CopyFileRange(int(sfd), &srcOffset, int(dfd), &dstOffset, int(n), 0)
})
})
if err != nil {
// sd.Control failed
return int64(resN), err
}
if err2 != nil {
// ss.Control failed
return int64(resN), err2
}
// err3 is ioctl() response
return int64(resN), err3
}
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