| Message ID | 20200930094606.5323-1-cenjiahui@huawei.com |
|---|---|
| Headers | show |
| Series | block-backend: Introduce I/O hang | expand |
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(+) >
On 10/10/2020 10:27 AM, cenjiahui wrote: > Hi Kevin, > > Could you please spend some time reviewing and commenting on this patch series. > > Thanks, > Jiahui Cen This feature is confirmed effective in a cloud storage environment since it can help to improve the availability without pausing the entire guest. Hope it won't be lost on the thread. Any comments or reviews are welcome. > > 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(+) >> > . >