Kindly ping... On 2020/12/15 20:30, 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. In production environment, 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. However, > the error in the filesystem may not be recovered unless a device reattach > or system restart. Thus an I/O retry mechanism is in need to implement a > self-healing system. > > This patch series propose to extend the werror=/rerror= mechanism to add > a 'retry' feature. It can automatically retry failed I/O requests on error > without sending error back to guest, and guest can get back running smoothly > when I/O is recovred. > > v3->v4: > * Adapt to werror=/rerror= mechanism. > > v2->v3: > * Add a doc to describe I/O hang. > > v1->v2: > * Rebase to fix compile problems. > * Fix incorrect remove of rehandle list. > * Provide rehandle pause interface. > > REF: https://lists.gnu.org/archive/html/qemu-devel/2020-10/msg06560.html > > Signed-off-by: Jiahui Cen <cenjia...@huawei.com> > Signed-off-by: Ying Fang <fangyi...@huawei.com> > > Jiahui Cen (7): > qapi/block-core: Add retry option for error action > block-backend: Introduce retry timer > block-backend: Add device specific retry callback > block-backend: Enable retry action on errors > block-backend: Add timeout support for retry > block: Add error retry param setting > virtio_blk: Add support for retry on errors > > block/block-backend.c | 66 ++++++++++++++++++++ > blockdev.c | 52 +++++++++++++++ > hw/block/block.c | 10 +++ > hw/block/virtio-blk.c | 19 +++++- > include/hw/block/block.h | 7 ++- > include/sysemu/block-backend.h | 10 +++ > qapi/block-core.json | 4 +- > 7 files changed, 162 insertions(+), 6 deletions(-) >
