This patchset adds a new netlink configuration interface to NBD as well as a bunch of enhancments around path failures. The patches provide the following enhancemnts to NBD - Netlink configuration interface that doesn't leave a userspace application waiting in kernel space for the device to disconnect. - Netlink reconfigure interface for adding re-connected sockets to replace dead sockets. - A flag to destroy the NBD device on disconnect, much like how mount -o loop works. - A status interface that currently will only report whether a device is connected or not, but can be extended to include whatever in the future. - A netlink multicast notification scheme to notify user space when there are connection issues to allow for seamless reconnects. - Dead link handling. You can specify a dead link timeout and the NBD device will pause IO for that timeout waiting to see if the connection can be re-established. This is helpful to allow for things like nbd server upgrades where the whole server disappears for a short period of time. These patches have been thorougly and continuously tested for about a month. I've been finding bugs in various places, but this batch has been solid for the last few days of testing, which include a constant disconnect/reconnect torture test. Thanks, Josef
