Files added via files API get garbage collected

[kevina]

It seams that there is nothing protecting files added via the files API from being garbage collected:

$ ipfs version
ipfs version 0.4.1
$ echo "hello world"  | ipfs files write --create /hello.txt
$ ipfs files stat  /hello.txt
QmVib14uvPnCP73XaCDpwugRuwfTsVbGyWbatHAmLSdZUS
$ ipfs repo gc
...
removed QmVib14uvPnCP73XaCDpwugRuwfTsVbGyWbatHAmLSdZUS
...
$ ipfs cat QmVib14uvPnCP73XaCDpwugRuwfTsVbGyWbatHAmLSdZUS
Error: merkledag: not found

And I can't even remove the file:

$ ipfs files rm /hello.txt
Error: merkledag: not found

(but for some reason ipfs files rm -r /hello.txt works as a workaround).

Am I missing something?

[kevina]

If I understand how the files API works, the easiest way to fix this is to maintain a pin to the files root directory. Every time somethings changes the old pin will be removed and a new pin will be created to the new root.

Another way is to make the garbage collector aware of the files root node.

I think I can try implementing either option once we decide what we want to do. Fixing this will probably fix #2698.

Slightly related is @whyrusleeping idea of moving pinned objects inside the files api space (in a comment in issue #257). Although I thinks .pins would be better to prevent accidental removal if wildcards are eventually supported and someone does something like "ipfs files rm -r /*".