https://bugzilla.redhat.com/show_bug.cgi?id=1591732
If kernel is compiled without CONFIG_BLK_DEV_DM enabled, there is
no /dev/mapper/control device and since dm_task_create() actually
does some ioctl() over it creating a task may fail.
To cope with this handle ENOENT and ENODEV gracefully.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Just like in previous commit, qemu-pr-helper might want to open
/dev/mapper/control under certain circumstances. Therefore we
have to allow it in cgroups.
The change virdevmapper.c might look spurious but it isn't. After
6dd84f6850ca437 any path that we're allowing in deivces CGroup is
subject to virDevMapperGetTargets() inspection. And libdevmapper
returns ENXIO for the path from subject.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
This helper fetches dependencies for given device mapper target.
At the same time, we need to provide a dummy log function because
by default libdevmapper prints out error messages to stderr which
we need to suppress.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
