Re: Making forced unmounts work

[Martin Husemann <martin%duskware.de@localhost>]

I am interested, but I lack significant vnode clue. So, sorry if answers
are obvious - they are not to me.

About the only situation I ever (and it is almost reproducable at will), in
daily life, wanted to use forced unmounts instead of rebooting a machine (or
before the machine rebooted itself in direct consequence of the bug that
caused the inital issue) is a NFS mount combined with what probably are
network driver bugs (or maybe hardware).

I have multiple NFS servers where I better force all clients to use TCP
or smaller write windows, otherwise the clients will lock up on bigger
writes. AFAICT the nfs level creates the necessary packets (repeataly,
after appropriate timeouts etc.) and passes them to the driver, but the
driver (or the hardware, and most likely it is the receiving side on the
server) reproducably drops them, so no progress overall happens.

Would this situation be fixed by your patch or would the nfs layer still
hold the reader lock?

Martin