IB/srpt: Fix the RDMA completion handlers

Avoid that the following kernel crash is triggered when processing
an RDMA completion:

BUG: unable to handle kernel paging request at 0000000100000198
IP: [<ffffffff810a4ea2>] __lock_acquire+0xa2/0x560
Call Trace:
 [<ffffffff810a53c2>] lock_acquire+0x62/0x80
 [<ffffffff8151bd33>] _raw_spin_lock_irqsave+0x43/0x60
 [<ffffffffa04fd437>] srpt_rdma_read_done+0x57/0x120 [ib_srpt]
 [<ffffffffa0144dd3>] __ib_process_cq+0x43/0xc0 [ib_core]
 [<ffffffffa0145115>] ib_cq_poll_work+0x25/0x70 [ib_core]
 [<ffffffff8107184d>] process_one_work+0x1bd/0x460
 [<ffffffff81073148>] worker_thread+0x118/0x420
 [<ffffffff81078454>] kthread+0xe4/0x100
 [<ffffffff8151cbbf>] ret_from_fork+0x3f/0x70

Fixes: commit 59fae4de ("IB/srpt: chain RDMA READ/WRITE requests").
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/ulp/srpt/ib_srpt.c

@@ -1396,7 +1396,7 @@ static void srpt_rdma_read_done(struct ib_cq *cq, struct ib_wc *wc)
 {
 	struct srpt_rdma_ch *ch = cq->cq_context;
 	struct srpt_send_ioctx *ioctx =
-		container_of(wc->wr_cqe, struct srpt_send_ioctx, ioctx.cqe);
+		container_of(wc->wr_cqe, struct srpt_send_ioctx, rdma_cqe);
 
 	WARN_ON(ioctx->n_rdma <= 0);
 	atomic_add(ioctx->n_rdma, &ch->sq_wr_avail);
@@ -1419,7 +1419,7 @@ static void srpt_rdma_read_done(struct ib_cq *cq, struct ib_wc *wc)
 static void srpt_rdma_write_done(struct ib_cq *cq, struct ib_wc *wc)
 {
 	struct srpt_send_ioctx *ioctx =
-		container_of(wc->wr_cqe, struct srpt_send_ioctx, ioctx.cqe);
+		container_of(wc->wr_cqe, struct srpt_send_ioctx, rdma_cqe);
 
 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
 		pr_info("RDMA_WRITE for ioctx 0x%p failed with status %d\n",