firewire: fill_bus_reset_event needs lock protection
authorStefan Richter <stefanr@s5r6.in-berlin.de>
Fri, 6 Jun 2008 20:11:30 +0000 (22:11 +0200)
committerStefan Richter <stefanr@s5r6.in-berlin.de>
Wed, 18 Jun 2008 22:12:35 +0000 (00:12 +0200)
commit5cb84067d646fa3889463129dad8b218806b4698
tree081afef7668bf0e3e496fbefbe2d6256efb2d2dd
parentaffc9c24ade666f9903163c12686da567dbfe06f
firewire: fill_bus_reset_event needs lock protection

Callers of fill_bus_reset_event() have to take card->lock.  Otherwise
access to node data may oops if node removal is in progress.

A lockless alternative would be

- event->local_node_id = card->local_node->node_id;
+ tmp = fw_node_get(card->local_node);
+ event->local_node_id = tmp->node_id;
+ fw_node_put(tmp);

and ditto with the other node pointers which fill_bus_reset_event()
accesses.  But I went the locked route because one of the two callers
already holds the lock.  As a bonus, we don't need the memory barrier
anymore because device->generation and device->node_id are written in
a card->lock protected section.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
drivers/firewire/fw-cdev.c