tree c324a24baa26658651d2e1ecbf2771da569ff38b
parent 240286725d854331422cb15957f8d9bf2741d4e3
author Trond Myklebust <Trond.Myklebust@netapp.com> 1364225020 -0400
committer Trond Myklebust <Trond.Myklebust@netapp.com> 1364225020 -0400

SUNRPC: Add barriers to ensure read ordering in rpc_wake_up_task_queue_locked

We need to be careful when testing task->tk_waitqueue in
rpc_wake_up_task_queue_locked, because it can be changed while we
are holding the queue->lock.
By adding appropriate memory barriers, we can ensure that it is safe to
test task->tk_waitqueue for equality if the RPC_TASK_QUEUED bit is set.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org