Managed file system filter model and architecture

In a computing environment having an operating system and a file system, wherein the operating system includes a component that receives file system-related function calls and provides corresponding I/O request data directed to the file system, a system comprising:

• a plurality of filter drivers;
• and
• a filter manager that:
• a) registers each of the filter drivers;
• b) arranges the filter drivers in at least one pre-callback order, each pre-callback order corresponding to a set of one or more of the filter drivers;
• c) receives the request data;
• d) calls at least one of the filter drivers based on a selected pre-callback order, including providing callback data based on the request to each filter driver called;
• e) receives a status from each filter driver called;
• and
• f) passes an I/O request towards the file system including data corresponding to the callback data.

A computer-readable medium having stored thereon a data structure, comprising:

• a first set of information that identifies the structure as being associated with a type of file system I/O request;
• a second set of information that identifies a plurality of filter drivers associated with the type of file system I/O request;
• and
• a third set of information that identifies an ordering of the filter drivers with respect to one another;
• wherein in response to a file system I/O request corresponding to the first set of information, an entity calls each of the filter drivers in the second set with a pre-callback in an order determined by the third set of information.

In a computing environment, a method comprising:

• registering a plurality of filter drivers in a callback order, the plurality including an intermediate filter driver that is below a higher filter driver and is above a lower filter driver;
• receiving a file system-directed I/O request initiated at the intermediate filter driver;
• maintaining information that indicates that the I/O request was initiated by the intermediate filter driver;
• sending the I/O request towards the file system;
• receiving status data from the file system corresponding to the I/O request;
• returning the status data to the intermediate filter driver that initiated the I/O request;
• and
• accessing the information that indicates that the I/O request was initiated by the intermediate filter driver so as to not pass the status data to the higher filter driver.