Re: [PATCH v2 01/18] migration: Fix file migration with fdset

[Daniel P . Berrangé]

On Thu, May 23, 2024 at 04:05:31PM -0300, 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>
> Signed-off-by: Fabiano Rosas <farosas@suse.de>
> ---
>  migration/file.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>


With regards,
Daniel
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