FireWire fix

Linus, please pull from the fixes branch at

    git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6.git fixes

for a fix to a regression since v3.0-rc1. Thanks.

Chris Boot (1):
firewire: sbp2: fix panic after rmmod with slow targets

 drivers/firewire/sbp2.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

commit 0278ccd9d53e07c4e699432b2fed9de6c56f506c

Author: Chris Boot <[email protected]>
Date:   Mon Aug 22 21:38:38 2011 +0100

firewire: sbp2: fix panic after rmmod with slow targets

If firewire-sbp2 starts a login to a target that doesn't complete ORBs in a timely manner (and has to retry the login), and the module is removed before the operation times out, you end up with a null-pointer dereference and a kernel panic.

[SR: This happens because sbp2_target_get/put() do not maintain module references. scsi_device_get/put() do, but at occasions like Chris describes one, nobody holds a reference to an SBP-2 sdev.]

This patch cancels pending work for each unit in sbp2_remove(), which hopefully means there are no extra references around that prevent us from unloading. This fixes my crash.

index 41841a3..17cef86 100644
@@ -1198,6 +1198,10 @@ static int sbp2_remove(struct device *dev)
 {
 	struct fw_unit *unit = fw_unit(dev);
 	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
+	struct sbp2_logical_unit *lu;
+
+	list_for_each_entry(lu, &tgt->lu_list, link)
+		cancel_delayed_work_sync(&lu->work);
 
 	sbp2_target_put(tgt);
 	return 0;

Stefan Richter
-=====-==-== =--- ==-==
http://arcgraph.de/sr/