Loop over a dynamic nested struct in golang

I have created a dynamic struct to unmarshal a JSON.
Struct looks like :

type Partition struct {
	DiskName      string      `json:"disk_name"`
	Mountpoint    interface{} `json:"mountpoint,omitempty"`
	Size          string      `json:"size"`
	Fstype        string      `json:"fstype,omitempty"`
	SubPartitions bool        `json:"sub_partitions"`
	Partitions    []Partition `json:"partitions,omitempty"`
}

type NasInfo struct {
	Blockdevices []struct {
		DiskName   string      `json:"disk_name"`
		Mountpoint interface{} `json:"mountpoint,omitempty"`
		Size       string      `json:"size"`
		Fstype     string      `json:"fstype,omitempty"`
		Partitions []Partition `json:"partitions,omitempty"`
	} `json:"blockdevices"`
}

Now there can be many partitions inside block devices, and a partition can have more sub partitions in it. I want to manually assign value to a field in partition struct. How can i do that.
How can i iterate over each partition and sub partitions and assign a manual value to it.
Is there any way to do this ?

Currently using this :

	totalPartitions := len(diskInfo.Blockdevices[0].Partitions)
	if totalPartitions > 0 {
		for i := 0; i < totalPartitions; i++ {
			if diskInfo.Blockdevices[0].Partitions[i].Partitions != nil {
				diskInfo.Blockdevices[0].Partitions[i].SubPartitions = true
			} else {
				diskInfo.Blockdevices[0].Partitions[i].SubPartitions = false
			}
		}
	}

But it can only handle 1 partition with one sub partition. Is there any way i can iterate over each and assign value to it?

Since that SubPartitions flag is coupled with Partitions, one option is to remove the SubPartitions field, and add a method that computes this value :

func (p *Partition) HasSubPartitions() bool {
    // note : to check if a slice is empty or not, it is advised to look at
    // 'len(slice)' rather than nil (it is possible to have a non-nil pointer
    // to a 0 length slice)
    return len(p.Partitions) > 0  
}

Write a function

func markSubPartition(p *Partition) {
if len(p.Partitions) > 0 {
	p.SubPartitions = true
	for _, part := range p.Partitions {
		markSubPartition(part)
	}
} else {
	p.SubPartitions = false
}}

And loop over blockdevices like this

for _, part := range diskInfo.Blockdevices[0].Partitions {
				markSubPartition(part)}

Also need to alter your struct change partition field to :
Partitions []*Partition json:"partitions,omitempty"
Hope it helps, Thanks!