virtio/s390: fix race on airq_areas[]
authorHalil Pasic <pasic@linux.ibm.com>
Tue, 23 Jul 2019 15:11:01 +0000 (17:11 +0200)
committerHeiko Carstens <heiko.carstens@de.ibm.com>
Fri, 26 Jul 2019 11:36:18 +0000 (13:36 +0200)
commit4f419eb14272e0698e8c55bb5f3f266cc2a21c81
tree104319c03391b176c77080df0292e26f7394a8a7
parent1a2dcff881059dedc14fafc8a442664c8dbd60f1
virtio/s390: fix race on airq_areas[]

The access to airq_areas was racy ever since the adapter interrupts got
introduced to virtio-ccw, but since commit 39c7dcb15892 ("virtio/s390:
make airq summary indicators DMA") this became an issue in practice as
well. Namely before that commit the airq_info that got overwritten was
still functional. After that commit however the two infos share a
summary_indicator, which aggravates the situation. Which means
auto-online mechanism occasionally hangs the boot with virtio_blk.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 96b14536d935 ("virtio-ccw: virtio-ccw adapter interrupt support.")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
drivers/s390/virtio/virtio_ccw.c