Re: [Qemu-devel] [PATCH 13/47] block: introduce block job error

[Kevin Wolf]

Am 01.08.2012 13:17, schrieb Paolo Bonzini:
> Il 01/08/2012 12:14, Kevin Wolf ha scritto:
>>>> Signed-off-by: Paolo Bonzini <address@hidden>
>> If we want to switch to named target block devices later, it would
>> probably make sense to use the io_status of that block device rather
>> than adding it to the job.
>>
>> Maybe what results is a duplication that can be tolerated, though.
> 
> We are probably thinking of two opposite implementations.
> 
> You are thinking:
> 
> - errors in streaming, or in the mirroring source go to the block device
> 
> - errors in the mirroring target go to the block job
> 
> What I implemented is:
> 
> - errors in streaming, or in the mirroring source go to the block job
> 
> - errors in the mirroring target go to the target block device (which as
> of this series could be inspected with query-block-jobs).

Ah, yes, I misunderstood.

> The reason is that an error in streaming or in the mirroring source does
> not stop the VM.  A hypothetical management that polled for errors with
> "info block" would see a mismatch between the error state ("failed") and
> the VM RunState ("running").
> 
> So this is already ready for making the target block device visible.
> 
> The real question is: if I remove the possibility to inspect the (so far
> anonymous) target device with query-block-jobs, how do you read the
> status of the target device?...

You don't? :-)

Maybe we should use named block devices from the beginning.

Kevin