Re: [PATCH v4 00/25] block layer: split block APIs in global state and I/O

[Hanna Reitz]

On 18.11.21 15:04, Paolo Bonzini wrote:
> On 11/15/21 17:03, Hanna Reitz wrote:
> > and second fuse_do_truncate(), which calls blk_set_perm().
>
> Here it seems that a non-growable export is still growable as long as 
> nobody is watching. :)  Is this the desired behavior?

Yes, absolutely.  “Growable” is documented to mean that writes after the 
end of the exported file will grow it to fit.  Explicit truncating is 
something else, and I believe we should allow it on all writable 
exports.  (Of course only when other potential users of the block node 
in question allow it to be resized, but that’s what the permission is for.)

Hanna