Re: [Qemu-devel] [PATCH v4] Stop VM on ENOSPC error.

[Ian Jackson]

Gleb Natapov writes ("Re: [Qemu-devel] [PATCH v4] Stop VM on ENOSPC error."):
> I would like to abolish the blocking calls from all file formats, but in
> reality it is almost impossible. Qcow2 metadata updates is a big mess to
> do asynchronously. The best thing we can do is to move it to another thread.

Err, I wasn't suggesting it should be done in each format in that way.
It could be done once in block.c, before the specific format write
method is called.

So the formats would still write synchronously, and would pass errors
up to their parent formats, until it reenters the generic block code
where the retry would take place.  At that point the call from the
device emulation would necessariy be asynchronous.

Ian.