Concurrent add and pin doesn't work

[Stebalien]

... unless ipfs add --pin=false is specified. It looks like we're taking the pin lock too early somewhere.

[Stebalien]

This is not new. It has been an issue since before 0.4.13.

It looks like ipfs pin add takes a write lock on the pinset before starting the pin.

[Stebalien]

Wow, the pinner doesn't even have access to the pin lock.

[bonedaddy]

Let me know if there's anything I can do to help with this

[bonedaddy]

@Stebalien Currently in my system I have a queue that process IPFS pin requests, and a queue that processes IPFS file add requests, which is how I initially saw this issue occur, when one queue was attempting to add a file, and the other was attempting to pin something else

Since the issue occurs will attempting to add a file with a pin, while also pinning; would a reasonable solution be to add files with no pin, then have a seperate process pin the content to my IPFS node?

[Stebalien]

Test case:

ipfs dag put <<<'{"link": {"/": "QmdZmoS1b1jp9vL5vgTyebEYUVH6zjd6erhp3fpqV1Zktx"}}'
ipfs pin add zdpuAsWv1LNwtxvFB3iTQjtwDLxPxRaa3WeE4i6BoDuKDy4gf &
echo "thing" | ipfs add

The last two commands should block indefinitely.

[Stebalien]

So, it turns out that we simply have a hidden requirement here: We need to take the GCLock before taking the pin lock.

Actually, after thinking about this, we can't even take this lock from within pinner.Pin as the caller may be holding it.