qemu /
qemu /
539343c0a47e19d5dd64d846d64d084d9793681f dma-helpers: ensure AIO callback is invoked after cancellation
dma_aio_cancel unschedules the BH if there is one, which corresponds
to the reschedule_dma case of dma_blk_cb. This can stall the DMA
permanently, because dma_complete will never get invoked and therefore
nobody will ever invoke the original AIO callback in dbs->common.cb.
Fix this by invoking the callback (which is ensured to happen after
a bdrv_aio_cancel_async, or done manually in the dbs->bh case), and
add assertions to check that the DMA state machine is indeed waiting
for dma_complete or reschedule_dma, but never both.
Reported-by: John Snow <jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20190729213416.1972-1-pbonzini@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
1 file changed
