• Haggai Eran's avatar
    IB/core: lock client data with lists_rwsem · 7c1eb45a
    Haggai Eran authored
    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: default avatarJason Gunthorpe <jgunthorpe@obsidianresearch.com>
    Signed-off-by: default avatarHaggai Eran <haggaie@mellanox.com>
    Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
    7c1eb45a
user_mad.c 33.6 KB