When a node runs
ipfs cat or
ipfs get to retrieve a file which does not exist in its local storage, the node will download the file from peers by looking at the DHT, and then cache the downloaded file. At this moment,
ipfs dht findprovs shows that the node is on the DHT list, which is normal and reasonable because the node does have a copy of the file for sharing.
But later when the node runs
ipfs repo gc, the cached file is deleted. This time,
ipfs dht findprovs still shows that the node is still on the DHT list. However, since the file is garbage collected, the node cannot help the download. Is there anything the node can do after garbage collection to update DHT such that DHT can reflect the truth which files the node has.