Re: [Qemu-devel] [PATCH v2 4/7] block: take lock around bdrv_read implementations

[Paolo Bonzini]

On 11/06/2011 03:27 PM, Avi Kivity wrote:
> On 10/20/2011 01:16 PM, Paolo Bonzini wrote:
> > This does the first part of the conversion to coroutines, by
> > wrapping bdrv_read implementations to take the read side of the
> > rwlock.
> >
> > Drivers that implement bdrv_read rather than bdrv_co_readv can
> > then benefit from asynchronous operation (at least if the underlying
> > protocol supports it, which is not the case for raw-win32), even
> > though they still operate with a bounce buffer.
> >
> > raw-win32 does not need the lock, because it cannot yield.
> > nbd also doesn't probably, but better be safe.
>
> This patch (2914caa088e3fbbd) breaks autotest when a guest reboots after
> install; instead of rebooting, the guest is stuck in the bootloader or
> kernel.

Are any of these formats used by autotest?

 block/bochs.c     |   13 ++++++++++++-
 block/cloop.c     |   13 ++++++++++++-
 block/cow.c       |   13 ++++++++++++-
 block/dmg.c       |   13 ++++++++++++-
 block/nbd.c       |   13 ++++++++++++-
 block/parallels.c |   13 ++++++++++++-
 block/vmdk.c      |   13 ++++++++++++-
 block/vpc.c       |   13 ++++++++++++-
 block/vvfat.c     |   13 ++++++++++++-
 9 files changed, 108 insertions(+), 9 deletions(-)

Perhaps the failure is only reproduced 80-90% of the time and this 
screws up the bisection.

Paolo