Re: [Qemu-block] [Qemu-devel] [PATCH 5/5] block: Move request_alignment into BlockLimit

[Paolo Bonzini]

On 07/06/2016 12:08, Kevin Wolf wrote:
>>> > > Something in this patch is causing qemu-iotests 77 to infloop; we may
>>> > > decide it is just easier to drop this patch rather than find all the
>>> > > places where the request_alignment must be preserved across what
>>> > > otherwise zeroes out limits.
>> > 
>> > Found it; squash this in (or use it as an argument why we don't want
>> > request_alignment in bs->bl after all):
> This hunk doesn't make sense to me. For the correctness of the code it
> shouldn't make a difference whether the alignment happens before passing
> the request to file/raw-posix or already in the raw format layer.
> 
> The cause for the hang you're seeing is probably that the request is
> already aligned before the blkdebug layer and therefore the blkdebug
> events aren't generated any more. That's a problem with the test (I'm
> considering the blkdebug events part of the test infrastructure),
> however, and not with the code.

Perhaps you could add an alignment option to blkdebug (or in general
options to force block limits on blkdebug), which would help testing in
general?

Thanks,

Paolo