Which mutex to lock when accessing a "struct ifnet*" ?

[John Giacomoni]

I'm writing some code which examines the the state of a "struct ifnet*"
as returned by "ifunit".

In what situations is it possible for the "struct <foo>_softc"
to be deleted taking it's "struct ifnet" with it?
Does it never go away?

I assume it is possible for the structure to go away given
support for pcmcia cards.

Is Giant the correct lock as suggested by the /usr/src/sys/net/bpf.c
(when it calls ifpromisc) to protect against this occurrence?
doesn't seem right as my understanding is Giant is being eliminated.

The other assumption would be struct ifnet's own mutex but there
would be a race to locking it after one gets a reference to it
(via ifunit).

Ideas?

thanks

John G


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University of Colorado at Boulder          John.Giacomoni at colorado.edu
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