Re: [Qemu-devel] [PATCH] block-backend: Always notify on blk_eject

[Kevin Wolf]

Am 28.10.2016 um 23:30 hat John Snow geschrieben:
> On 10/28/2016 05:23 PM, John Snow wrote:
> >blk_eject is only used by scsi-disk and atapi, and in both cases we
> >only attempt to invoke blk_eject if we have a bona-fide change in
> >tray state.
> >
> >The "issue" here is that the tray state does not generate a QMP event
> >unless there is a medium/BDS attached to the device, so if libvirt et al
> >are waiting for a tray event to occur from an empty-but-closed drive,
> >software opening that drive will not emit an event and libvirt will
> >wait forever.
> >
> >Change this by modifying blk_eject to always emit an event, instead of
> >conditionally on a "real" backend eject.
> >
> >Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1373264
> >
> >Reported-by: Peter Krempa <address@hidden>
> >Signed-off-by: John Snow <address@hidden>
> >---
> > block/block-backend.c | 13 +++++++------
> > 1 file changed, 7 insertions(+), 6 deletions(-)
> >
> >diff --git a/block/block-backend.c b/block/block-backend.c
> >index c53ca30..2044f20 100644
> >--- a/block/block-backend.c
> >+++ b/block/block-backend.c
> >@@ -1381,15 +1381,16 @@ void blk_eject(BlockBackend *blk, bool eject_flag)
> >     /* blk_eject is only called by qdevified devices */
> >     assert(!blk->legacy_dev);
> >
> >+    id = blk_get_attached_dev_id(blk);
> 
> Uhh, whoops, I left a change in my local branch that kept this right
> before the tray event. Sorry about that.

The patch looks good to me, but moving the line would indeed be nicer.
Are you going to send a v2 then?

Also, at the risk of sounding like a broken record, I think a test case
would be nice.

Kevin