1. In a computing environment, a method comprising: receiving a file system I/O request directed towards the file system; calling a first filter driver with a pre-callback based on a pre-callback order, including passing data that corresponds to the I/O request to the first filter driver; calling at least one other filter driver with another pre-callback, including calling a last filter driver based on the pre-callback order, including passing data that corresponds to the I/O request to the last filter driver; and passing the file system I/O request to the file system, the file system I/O request including data corresponding to the I/O request that was processed by at least one of the filter drivers.