[PATCH] firewire: fw-core: enforce write order when updatingfw_device.generation

[Stefan Richter]

fw_device.node_id and fw_device.generation are accessed without mutexes.
We have to ensure that all readers will get to see node_id updates
before generation updates.

Signed-off-by: Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx>
---
 drivers/firewire/fw-device.c   |    6 ++++++
 drivers/firewire/fw-topology.c |    1 +
 2 files changed, 7 insertions(+)

Index: linux/drivers/firewire/fw-device.c
===================================================================
--- linux.orig/drivers/firewire/fw-device.c
+++ linux/drivers/firewire/fw-device.c
@@ -808,6 +813,7 @@ void fw_node_event(struct fw_card *card,
 
 		device = node->data;
 		device->node_id = node->node_id;
+		wmb();
 		device->generation = card->generation;
 		if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
 			PREPARE_DELAYED_WORK(&device->work, fw_device_update);
Index: linux/drivers/firewire/fw-topology.c
===================================================================
--- linux.orig/drivers/firewire/fw-topology.c
+++ linux/drivers/firewire/fw-topology.c
@@ -518,6 +518,7 @@ fw_core_handle_bus_reset(struct fw_card 
 		card->bm_retries = 0;
 
 	card->node_id = node_id;
+	wmb();
 	card->generation = generation;
 	card->reset_jiffies = jiffies;
 	schedule_delayed_work(&card->work, 0);

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

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