From e9008a5b12dfd2fb54ff892605543d07841e7d2a Mon Sep 17 00:00:00 2001
From: Vladislav Bolkhovitin <vst@vlnb.net>
Date: Tue, 11 Sep 2012 20:38:57 +0000
Subject: [PATCH] Fix possible BUG_ON() on multiple forced commands release

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@4513 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 iscsi-scst/kernel/iscsi.c | 26 +++++++++++++++++++++++++-
 iscsi-scst/kernel/iscsi.h |  1 +
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/iscsi-scst/kernel/iscsi.c b/iscsi-scst/kernel/iscsi.c
index 190670a50..d6b502728 100644
--- a/iscsi-scst/kernel/iscsi.c
+++ b/iscsi-scst/kernel/iscsi.c
@@ -542,7 +542,30 @@ void req_cmnd_release_force(struct iscsi_cmnd *req)
 
 	TRACE_ENTRY();
 
-	TRACE_MGMT_DBG("req %p", req);
+	if (req->force_release_done) {
+		/*
+		 * There are some scenarios when this function can be called
+		 * more, than once, for the same req. For instance, dropped
+		 * command in iscsi_push_cmnd() and then for it
+		 * iscsi_fail_data_waiting_cmnd() during closing (aborting) this
+		 * connection or from iscsi_check_tm_data_wait_timeouts().
+		 */
+		TRACE_MGMT_DBG("Double force release for req %p", req);
+
+		EXTRACHECKS_BUG_ON(!req->release_called);
+		sBUG_ON(req->hashed);
+		sBUG_ON(req->cmd_req);
+		sBUG_ON(req->main_rsp != NULL);
+		sBUG_ON(!list_empty(&req->rx_ddigest_cmd_list));
+		sBUG_ON(!list_empty(&req->rsp_cmd_list));
+		sBUG_ON(req->pending);
+
+		cmnd_put(req);
+		goto out;
+	} else
+		TRACE_MGMT_DBG("req %p", req);
+
+	req->force_release_done = 1;
 
 	sBUG_ON(req == conn->read_cmnd);
 
@@ -601,6 +624,7 @@ void req_cmnd_release_force(struct iscsi_cmnd *req)
 
 	req_cmnd_release(req);
 
+out:
 	TRACE_EXIT();
 	return;
 }
diff --git a/iscsi-scst/kernel/iscsi.h b/iscsi-scst/kernel/iscsi.h
index cf0faf99a..06a6d84d3 100644
--- a/iscsi-scst/kernel/iscsi.h
+++ b/iscsi-scst/kernel/iscsi.h
@@ -384,6 +384,7 @@ struct iscsi_cmnd {
 	 * req_cmnd_release() supposed to be called only once.
 	 */
 	unsigned int data_out_in_data_receiving:1;
+	unsigned int force_release_done:1;
 #ifdef CONFIG_SCST_EXTRACHECKS
 	unsigned int on_rx_digest_list:1;
 	unsigned int release_called:1;