From d22ba32ea146e2c9b70f3fce465148a4a70e2505 Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bart.vanassche@sandisk.com>
Date: Sat, 2 May 2015 10:05:35 +0200
Subject: [PATCH] scst: Avoid that a high I/O load prevents activity to be
 suspended

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
---
 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 82aeef962..3bbdd573b 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
@@ -691,6 +692,14 @@ bool __scst_check_blocked_dev(struct scst_cmd *cmd);
 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.