Cluster storage System IO path inlet and outlet valve control

The IO path is the data channel of the storage system, the inlet and outlet have the controllable valve mechanism, sometimes the entrance is also the exit, especially in the distributed cluster the problem of the brain fissure needs its support.

Related points in the kernel

1. Freeze function of the file system VFS layer;

2.DM especially MP This block has the queue suspend function; This block can effectively manage the IO request when the multipath path fails, and the path will be re-sent after recovery;

3.MD this piece of suspend support;