GC and MFS are not safe

[Stebalien]

We don't hold any form of GC lock while adding files to MFS.

[@schomatis] Possible related items to revisit after applying the MFS global lock:

• Garbage collector deletes data stored in the MFS (which was pinned) #7008
• ipfs block rm is not safe #6310
• lockup while running files cp #7844

[jaccarmac]

Is there a way to work around this short of manually pinning everything added to the root of MFS?

[Kubuxu]

@jaccarmac after a file is in MFS it is safe.
GC and MFS operations at the same time are currently not safe.