unmount (fix) fuse after unclean shutdown

[jbenet]

Sometimes when ipfs shuts down it fails to unmount fuse. (may have been killed early, crashed, etc).

We need:

• functionality to "really, really" unmount fuse.
• should be called when ipfs starts up. (though, careful, there may be multiple ipfs daemons running!)
• should be callable from something like ipfs mount clean [ <path> ] or ipfs mount --fix [ <path> ]

I think we need to think through this one for a bit.

cc @whyrusleeping @tv42

[jbenet]

On linux, one of these works for me:

fusermount -u /ipfs
fusermount -u /ipns
sudo fusermount -u /ipfs
sudo fusermount -u /ipns
umount /ipfs
umount /ipns
umount -f /ipfs
umount -f /ipns
sudo umount -f /ipfs
sudo umount -f /ipns

On osx, one of these works for me:

umount /ipfs
umount /ipns
umount -f /ipfs
umount -f /ipns
sudo umount -f /ipfs
sudo umount -f /ipns
diskutil unmount /ipfs
diskutil unmount /ipns
diskutil unmount force /ipfs
diskutil unmount force /ipns
sudo diskutil unmount force /ipfs
sudo diskutil unmount force /ipns

[wking]

On Mon, May 18, 2015 at 05:18:28PM -0700, Juan Batiz-Benet wrote:

(though, careful, there may be multiple ipfs daemons running!)

But only one of them is servicing the FUSE requests for a given
mount-point, right?

[wking]

On Mon, May 18, 2015 at 05:22:43PM -0700, Juan Batiz-Benet wrote:

fusermount -u /ipfs
fusermount -u /ipns

If you have something currently working on the mounted filesystem
(e.g. ‘find /ipns’), you may need to use the ‘-z’ option too.

[tv42]

Lazy unmounts leave the server process alive -> file locks are still held, can't run a new ipfs command, etc.

[whyrusleeping]

👍 this needs some more UX work

[linas]

But issue #1092 is related, and its marked resolved: things do get unmounted...

[Stebalien]

These are two separate issues. In that case, we weren't unmounting on Ctrl+C. In this case, the daemon is getting killed (no chance to unmount). We need to handle cleaning up the mount points the next time we start.