// https://github.com/docker/docker/blob/master/pkg/archive/archive_unix.go
// Add a file's device major and minor numbers
// to the file's header within a tar archive.
// Return the file's inode and the number of hardlinks to that inode.
func tarSetHeader(hdr *tar.Header, stat interface{}) (hasHardLinks bool, inode uint64, err error) {
s, ok := stat.(*syscall.Stat_t)
if !ok {
err = fmt.Errorf("cannot convert stat value to syscall.Stat_t")
return
}
hasHardLinks = (uint32(s.Nlink) > 1)
inode = uint64(s.Ino)
// Currently go does not fil in the major/minors
if s.Mode&syscall.S_IFBLK != 0 || s.Mode&syscall.S_IFCHR != 0 {
hdr.Devmajor = int64(devmajor(uint64(s.Rdev)))
hdr.Devminor = int64(devminor(uint64(s.Rdev)))
}
return
}
func setHeaderForSpecialDevice(hdr *tar.Header, ta *tarAppender, name string, stat interface{}) (inode uint64, err error) {
s, ok := stat.(*syscall.Stat_t)
if !ok {
err = errors.New("cannot convert stat value to syscall.Stat_t")
return
}
inode = uint64(s.Ino)
// Currently go does not fill in the major/minors
if s.Mode&syscall.S_IFBLK != 0 ||
s.Mode&syscall.S_IFCHR != 0 {
hdr.Devmajor = int64(major(uint64(s.Rdev)))
hdr.Devminor = int64(minor(uint64(s.Rdev)))
}
return
}
func populateHeaderUnix(h *tar.Header, fi os.FileInfo, seen map[uint64]string) {
st, ok := fi.Sys().(*syscall.Stat_t)
if !ok {
return
}
h.Uid = int(st.Uid)
h.Gid = int(st.Gid)
if st.Mode&syscall.S_IFMT == syscall.S_IFBLK || st.Mode&syscall.S_IFMT == syscall.S_IFCHR {
h.Devminor = int64(C.my_minor(C.dev_t(st.Rdev)))
h.Devmajor = int64(C.my_major(C.dev_t(st.Rdev)))
}
// If we have already seen this inode, generate a hardlink
p, ok := seen[uint64(st.Ino)]
if ok {
h.Linkname = p
h.Typeflag = tar.TypeLink
} else {
seen[uint64(st.Ino)] = h.Name
}
}