SUNRPC: Fix potential races in xprt_lock_write_next()
We have to ensure that the wake up from the waitqueue and the assignment
of xprt->snd_task are atomic. We can do this by assigning the snd_task
while under the waitqueue spinlock.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 360240c..828a765 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -385,17 +385,20 @@
free_slotid, tbl->highest_used_slotid);
}
+bool nfs4_set_task_privileged(struct rpc_task *task, void *dummy)
+{
+ rpc_task_set_priority(task, RPC_PRIORITY_PRIVILEGED);
+ return true;
+}
+
/*
* Signal state manager thread if session fore channel is drained
*/
static void nfs4_check_drain_fc_complete(struct nfs4_session *ses)
{
- struct rpc_task *task;
-
if (!test_bit(NFS4_SESSION_DRAINING, &ses->session_state)) {
- task = rpc_wake_up_next(&ses->fc_slot_table.slot_tbl_waitq);
- if (task)
- rpc_task_set_priority(task, RPC_PRIORITY_PRIVILEGED);
+ rpc_wake_up_first(&ses->fc_slot_table.slot_tbl_waitq,
+ nfs4_set_task_privileged, NULL);
return;
}