SUNRPC: Set alloc_slot for backchannel tcp ops
f39c1bfb5a03e2d255451bff05be0d7255298fa4 (SUNRPC: Fix a UDP transport
regression) introduced the "alloc_slot" function for xprt operations,
but never created one for the backchannel operations. This patch fixes
a null pointer dereference when mounting NFS over v4.1.
Call Trace:
[<
ffffffffa0207957>] ? xprt_reserve+0x47/0x50 [sunrpc]
[<
ffffffffa02023a4>] call_reserve+0x34/0x60 [sunrpc]
[<
ffffffffa020e280>] __rpc_execute+0x90/0x400 [sunrpc]
[<
ffffffffa020e61a>] rpc_async_schedule+0x2a/0x40 [sunrpc]
[<
ffffffff81073589>] process_one_work+0x139/0x500
[<
ffffffff81070e70>] ? alloc_worker+0x70/0x70
[<
ffffffffa020e5f0>] ? __rpc_execute+0x400/0x400 [sunrpc]
[<
ffffffff81073d1e>] worker_thread+0x15e/0x460
[<
ffffffff8145c839>] ? preempt_schedule+0x49/0x70
[<
ffffffff81073bc0>] ? rescuer_thread+0x230/0x230
[<
ffffffff81079603>] kthread+0x93/0xa0
[<
ffffffff81465d04>] kernel_thread_helper+0x4/0x10
[<
ffffffff81079570>] ? kthread_freezable_should_stop+0x70/0x70
[<
ffffffff81465d00>] ? gs_change+0x13/0x13
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>