Am 31.10.2023 um 12:54 hat Hanna Czenczek geschrieben: > On 13.10.23 17:33, Kevin Wolf wrote: > > blk_insert_bs() requires that the caller holds the AioContext lock for > > the node to be inserted. Since commit c066e808e11, neglecting to do so > > causes a crash when the child has to be moved to a different AioContext > > to attach it to the BlockBackend. > > > > This fixes qmp_blockdev_insert_anon_medium(), which is called for the > > QMP commands 'blockdev-insert-medium' and 'blockdev-change-medium', to > > correctly take the lock. > > > > Cc: qemu-sta...@nongnu.org > > Fixes: https://issues.redhat.com/browse/RHEL-3922 > > Fixes: c066e808e11a5c181b625537b6c78e0de27a4801 > > Signed-off-by: Kevin Wolf <kw...@redhat.com> > > --- > > block/qapi-sysemu.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > Do we need to take the lock for the dev_ops tray callbacks, too? I suppose > not, and it also wouldn’t really matter in light of the lock being supposed > to go away anyway, but still thought I should ask.
Seems nobody ever bothered to define what the callbacks expects, and I don't know either. Not taking the lock can obviously be a problem, but taking it can also be a problem if the callback then locks a second time and calls a synchronous function that polls. What I do see is that callers disagree about this, so no matter what the correct answer is, I'm almost sure there is a bug hiding somewhere. Kevin
