On 1/29/21 1:38 AM, Roman Kagan wrote:
> During the final phase of migration the NBD reconnection logic may
> encounter situations it doesn't expect during regular operation.
>
> This series addresses some of them that make qemu crash. They are
> reproducible when a vm with a secondary drive attached via nbd with
> non-zero "reconnect-delay" runs a stress load (fio with big queue depth)
> in the guest on that drive and is migrated (e.g. to a file), while the
> nbd server is SIGKILL-ed and restarted every second.
>
> See the individual patches for specific crash conditions and more
> detailed explanations.
>
> v1 -> v2:
> - fix corrupted backtraces in log messages
> - add r-b by Vladimir
>
Thanks, queuing through my NBD tree.
> Roman Kagan (3):
> block/nbd: only detach existing iochannel from aio_context
> block/nbd: only enter connection coroutine if it's present
> nbd: make nbd_read* return -EIO on error
>
> include/block/nbd.h | 7 ++++---
> block/nbd.c | 25 +++++++++++++++++--------
> 2 files changed, 21 insertions(+), 11 deletions(-)
>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org