IB/core: lock client data with lists_rwsem
An ib_client callback that is called with the lists_rwsem locked only for
read is protected from changes to the IB client lists, but not from
ib_unregister_device() freeing its client data. This is because
ib_unregister_device() will remove the device from the device list with
lists_rwsem locked for write, but perform the rest of the cleanup,
including the call to remove() without that lock.
Mark client data that is undergoing de-registration with a new going_down
flag in the client data context. Lock the client data list with lists_rwsem
for write in addition to using the spinlock, so that functions calling the
callback would be able to lock only lists_rwsem for read and let callbacks
sleep.
Since ib_unregister_client() now marks the client data context, no need for
remove() to search the context again, so pass the client data directly to
remove() callbacks.
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/net/rds/ib.c b/net/rds/ib.c
index ba2dffe..348ac37 100644
--- a/net/rds/ib.c
+++ b/net/rds/ib.c
@@ -230,11 +230,10 @@
*
* This can be called at any time and can be racing with any other RDS path.
*/
-static void rds_ib_remove_one(struct ib_device *device)
+static void rds_ib_remove_one(struct ib_device *device, void *client_data)
{
- struct rds_ib_device *rds_ibdev;
+ struct rds_ib_device *rds_ibdev = client_data;
- rds_ibdev = ib_get_client_data(device, &rds_ib_client);
if (!rds_ibdev)
return;