Re: [PATCH v3 02/16] migration: Fix file migration with fdset

[Peter Xu <peterx@redhat.com>]

On Sat, Jun 22, 2024 at 07:21:52AM +0300, Michael Tokarev wrote:
> 17.06.2024 21:57, Fabiano Rosas wrote:
> > When the "file:" migration support was added we missed the special
> > case in the qemu_open_old implementation that allows for a particular
> > file name format to be used to refer to a set of file descriptors that
> > have been previously provided to QEMU via the add-fd QMP command.
> > 
> > When using this fdset feature, we should not truncate the migration
> > file because being given an fd means that the management layer is in
> > control of the file and will likely already have some data written to
> > it. This is further indicated by the presence of the 'offset'
> > argument, which indicates the start of the region where QEMU is
> > allowed to write.
> > 
> > Fix the issue by replacing the O_TRUNC flag on open by an ftruncate
> > call, which will take the offset into consideration.
> > 
> > Fixes: 385f510df5 ("migration: file URI offset")
> > Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
> > Reviewed-by: Prasad Pandit <pjp@fedoraproject.org>
> > Reviewed-by: Peter Xu <peterx@redhat.com>
> > Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
> > Signed-off-by: Fabiano Rosas <farosas@suse.de>
> > ---
> >   migration/file.c | 11 +++++++++--
> >   1 file changed, 9 insertions(+), 2 deletions(-)
> 
> Is it a stable material?

I suppose yes. Thanks.

-- 
Peter Xu