From a77563897a60447ed6964631995eefeeb17d1393 Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Sat, 5 Jan 2019 21:56:37 +0000
Subject: [PATCH] scst: Avoid that a high I/O load prevents activity to be
 suspended

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@7862 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 scst/src/scst_priv.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/scst/src/scst_priv.h b/scst/src/scst_priv.h
index d617ed949..063a7f083 100644
--- a/scst/src/scst_priv.h
+++ b/scst/src/scst_priv.h
@@ -21,6 +21,7 @@
 
 #include <linux/types.h>
 #include <linux/slab.h>
+#include <linux/delay.h>
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 2, 0)
 #include <linux/export.h>
 #endif
@@ -773,6 +774,14 @@ int scst_get_suspend_count(void);
 static inline atomic_t *scst_get(void)
 {
 	atomic_t *a;
+
+	/*
+	 * Avoid that a high I/O load prevents activity to be suspended. See
+	 * also http://sourceforge.net/p/scst/mailman/message/34074831/.
+	 */
+	if (unlikely(test_bit(SCST_FLAG_SUSPENDING, &scst_flags)))
+		mdelay(100);
+
 	/*
 	 * We don't mind if we because of preemption inc counter from another
 	 * CPU as soon in the majority cases we will the correct one.