Hi Kevin, Could you please spend some time reviewing and commenting on this patch series.
Thanks, Jiahui Cen On 2020/9/30 17:45, Jiahui Cen wrote: > A VM in the cloud environment may use a virutal disk as the backend storage, > and there are usually filesystems on the virtual block device. When backend > storage is temporarily down, any I/O issued to the virtual block device will > cause an error. For example, an error occurred in ext4 filesystem would make > the filesystem readonly. However a cloud backend storage can be soon > recovered. > For example, an IP-SAN may be down due to network failure and will be online > soon after network is recovered. The error in the filesystem may not be > recovered unless a device reattach or system restart. So an I/O rehandle is > in need to implement a self-healing mechanism. > > This patch series propose a feature called I/O hang. It can rehandle AIOs > with EIO error without sending error back to guest. From guest's perspective > of view it is just like an IO is hanging and not returned. Guest can get > back running smoothly when I/O is recovred with this feature enabled. > > v1->v2: > * Rebase to fix compile problems. > * Fix incorrect remove of rehandle list. > * Provide rehandle pause interface. > > Jiahui Cen (8): > block-backend: introduce I/O rehandle info > block-backend: rehandle block aios when EIO > block-backend: add I/O hang timeout > block-backend: add I/O rehandle pause/unpause > block-backend: enable I/O hang when timeout is set > virtio-blk: pause I/O hang when resetting > qemu-option: add I/O hang timeout option > qapi: add I/O hang and I/O hang timeout qapi event > > block/block-backend.c | 300 +++++++++++++++++++++++++++++++++ > blockdev.c | 11 ++ > hw/block/virtio-blk.c | 8 + > include/sysemu/block-backend.h | 5 + > qapi/block-core.json | 26 +++ > 5 files changed, 350 insertions(+) >
