On Fri, 11/13 17:44, John Snow wrote:
>
>
> On 11/12/2015 11:30 AM, Peter Lieven wrote:
> > This series aims at avoiding a hanging main-loop if a vserver has a
> > CDROM image mounted from a NFS share and that NFS share goes down.
> > Typical situation is that users mount an CDROM ISO to install something
> > and then forget to eject that CDROM afterwards.
> > As a consequence this mounted CD is able to bring down the
> > whole vserver if the backend NFS share is unreachable. This is bad
> > especially if the CDROM itself is not needed anymore at this point.
> >
> > v3->v4: - Patch 1: remove buf argument for cd_read_sector{_sync}
> > - Patch 1: fix iov_base offset for 2352 sector size
> > - Patch 2: fix indent [Fam]
> > - Patch 3: fix leaking of req->iov.iov_base [Fam]
> >
> > v2->v3: - adressed Stefans comments on Patch 1
> > - added patches 2,4,5,6
> > - avoided the term cancel in Patch 3. Added an iovec,
> > added a BH [Stefan]
> > v1->v2: - fix offset for 2352 byte sector size [Kevin]
> > - use a sync request if we continue an elementary transfer.
> > As John pointed out we enter a race condition between next
> > IDE command and async transfer otherwise. This is sill not
> > optimal, but it fixes the NFS down problems for all cases where
> > the NFS server goes down while there is no PIO CD activity.
> > Of course, it could still happen during a PIO transfer, but I
> > expect this to be the unlikelier case.
> > I spent some effort trying to read more sectors at once and
> > avoiding continuation of elementary transfers, but with
> > whatever I came up it was destroying migration between different
> > Qemu versions. I have a quite hackish patch that works and
> > should survive migration, but I am not happy with it. So I
> > would like to start with this version as it is a big improvement
> > already.
> > - Dropped Patch 5 because it is upstream meanwhile.
> >
> > Peter Lieven (6):
> > ide/atapi: make PIO read requests async
> > block: add blk_abort_aio_request
> > ide: add support for IDEBufferedRequest
> > ide: orphan all buffered requests on DMA cancel
> > ide: enable buffered requests for ATAPI devices
> > ide: enable buffered requests for PIO read requests
> >
> > block/block-backend.c | 17 +++----
> > hw/ide/atapi.c | 103
> > +++++++++++++++++++++++++++++++++++------
> > hw/ide/core.c | 51 +++++++++++++++++++-
> > hw/ide/internal.h | 14 ++++++
> > hw/ide/pci.c | 19 ++++++++
> > include/sysemu/block-backend.h | 3 ++
> > 6 files changed, 182 insertions(+), 25 deletions(-)
> >
>
> It looks sane to me:
>
> Reviewed-by: John Snow <[email protected]>
>
> Fam, Stefan: Do you think this is still sane for 2.5? I am inclined to
> get it in as a fix, especially since we've been bouncing it around for
> so long.
I have no objection here, there is no new feature in the series, and guest
hanging right after installing something is admittedly annoying to users.
Thanks,
Fam
