From 15f48dd4eff02575dd83d020f2beb90b9c4b39de Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Mon, 19 Sep 2011 18:31:51 +0000
Subject: [PATCH] ib_srpt: Follow-up for r3873 (for modes thread == 0 or thread
 == 2 only)

git-svn-id: http://svn.code.sf.net/p/scst/svn/branches/2.1.0.x@3874 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 srpt/src/ib_srpt.c | 28 +++++++++++++++++++++++++++-
 srpt/src/ib_srpt.h |  1 +
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/srpt/src/ib_srpt.c b/srpt/src/ib_srpt.c
index 2239786c1..eb80fd97d 100644
--- a/srpt/src/ib_srpt.c
+++ b/srpt/src/ib_srpt.c
@@ -316,13 +316,30 @@ static void srpt_srq_event(struct ib_event *event, void *ctx)
 	PRINT_INFO("SRQ event %d", event->event);
 }
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20) && !defined(BACKPORT_LINUX_WORKQUEUE_TO_2_6_19)
+/* A vanilla 2.6.19 or older kernel without backported OFED kernel headers. */
+static void srpt_unreg_sess_work(void *ctx)
+#else
+static void srpt_unreg_sess_work(struct work_struct *work)
+#endif
+{
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20) && !defined(BACKPORT_LINUX_WORKQUEUE_TO_2_6_19)
+	struct srpt_rdma_ch *ch = (struct srpt_rdma_ch *)ctx;
+#else
+	struct srpt_rdma_ch *ch = container_of(work, struct srpt_rdma_ch,
+					       unreg_work);
+#endif
+
+	scst_unregister_session(ch->scst_sess, false, srpt_free_ch);
+}
+
 static void srpt_release_channel(struct srpt_rdma_ch *ch)
 {
 	TRACE_ENTRY();
 
 	if (srpt_test_and_set_channel_state(ch, CH_DRAINING, CH_RELEASING) &&
 	    thread != MODE_IB_COMPLETION_IN_THREAD) {
-		scst_unregister_session(ch->scst_sess, false, srpt_free_ch);
+		schedule_work(&ch->unreg_work);
 	}
 
 	TRACE_EXIT();
@@ -2476,6 +2493,15 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
 	ch->rq_size = min(SRPT_RQ_SIZE, scst_get_max_lun_commands(NULL, 0));
 	atomic_set(&ch->state, CH_CONNECTING);
 	INIT_LIST_HEAD(&ch->cmd_wait_list);
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20) && !defined(BACKPORT_LINUX_WORKQUEUE_TO_2_6_19)
+	/*
+	 * A vanilla 2.6.19 or older kernel without backported OFED
+	 * kernel headers.
+	 */
+	INIT_WORK(&ch->unreg_work, srpt_unreg_sess_work, ch);
+#else
+	INIT_WORK(&ch->unreg_work, srpt_unreg_sess_work);
+#endif
 
 	spin_lock_init(&ch->spinlock);
 	init_waitqueue_head(&ch->state_wq);
diff --git a/srpt/src/ib_srpt.h b/srpt/src/ib_srpt.h
index 508e71f08..af7578c34 100644
--- a/srpt/src/ib_srpt.h
+++ b/srpt/src/ib_srpt.h
@@ -305,6 +305,7 @@ struct srpt_rdma_ch {
 	struct list_head	list;
 	struct list_head	cmd_wait_list;
 	bool			last_wqe_received;
+	struct work_struct	unreg_work;
 
 	struct scst_session	*scst_sess;
 	u8			sess_name[36];