diff --git a/usr/fileio/debug.c b/usr/fileio/debug.c
index db0b87fd3..fc0cfadf7 100644
--- a/usr/fileio/debug.c
+++ b/usr/fileio/debug.c
@@ -20,6 +20,8 @@
 
 #include <stdio.h>
 #include <time.h>
+#include <pthread.h>
+#include <string.h>
 
 #include "debug.h"
 
@@ -30,14 +32,14 @@ _syscall0(pid_t,gettid);
 #define TRACE_BUF_SIZE    512
 
 static char trace_buf[TRACE_BUF_SIZE];
-//static spinlock_t trace_buf_lock = SPIN_LOCK_UNLOCKED;
+static pthread_spinlock_t trace_buf_lock;
 
 int debug_print_prefix(unsigned long trace_flag, const char *func, 
 			int line)
 {
 	int i = 0;
 
-//	spin_lock_irqsave(&trace_buf_lock, flags);
+	pthread_spin_lock(&trace_buf_lock);
 
 	if (trace_flag & TRACE_TIME) {
 		struct tm t;
@@ -58,7 +60,7 @@ int debug_print_prefix(unsigned long trace_flag, const char *func,
 	if (i > 0)
 		PRINTN("%s", trace_buf);
 
-//	spin_unlock_irqrestore(&trace_buf_lock, flags);
+	pthread_spin_unlock(&trace_buf_lock);
 
 	return i;
 }
@@ -72,7 +74,7 @@ void debug_print_buffer(const void *data, int len)
 	if (buf == NULL)
 		return;
 
-//	spin_lock_irqsave(&trace_buf_lock, flags);
+	pthread_spin_lock(&trace_buf_lock);
 
 	PRINT(" (h)___0__1__2__3__4__5__6__7__8__9__A__B__C__D__E__F");
 	for (z = 0, z1 = 0, i = 0; z < len; z++) {
@@ -113,8 +115,26 @@ void debug_print_buffer(const void *data, int len)
 		PRINT("%s", trace_buf);
 	}
 
-//	spin_unlock_irqrestore(&trace_buf_lock, flags);
+	pthread_spin_unlock(&trace_buf_lock);
 	return;
 }
 
+int debug_init(void)
+{
+	int res;
+
+	res = pthread_spin_init(&trace_buf_lock, PTHREAD_PROCESS_PRIVATE);
+	if (res != 0) {
+		res = errno;
+		PRINT_ERROR_PR("pthread_spin_init() failed: %s", strerror(res));
+	}
+
+	return res;
+}
+
+void debug_done(void)
+{
+	pthread_spin_destroy(&trace_buf_lock);
+}
+
 #endif /* DEBUG || TRACING */
diff --git a/usr/fileio/debug.h b/usr/fileio/debug.h
index 892e9ec63..e2dba9ede 100644
--- a/usr/fileio/debug.h
+++ b/usr/fileio/debug.h
@@ -64,6 +64,9 @@ extern char *app_name;
 
 extern unsigned long trace_flag;
 
+extern int debug_init(void);
+extern void debug_done(void);
+
 extern int debug_print_prefix(unsigned long trace_flag, const char *func, int line);
 extern void debug_print_buffer(const void *data, int len);
 
diff --git a/usr/fileio/fileio.c b/usr/fileio/fileio.c
index dfb7e7cb0..6e392ff5d 100644
--- a/usr/fileio/fileio.c
+++ b/usr/fileio/fileio.c
@@ -166,6 +166,10 @@ int main(int argc, char **argv)
 
 	setlinebuf(stdout);
 
+	res = debug_init();
+	if (res != 0)
+		goto out;
+
 	app_name = argv[0];
 
 	memset(&dev, 0, sizeof(dev));
@@ -254,7 +258,7 @@ int main(int argc, char **argv)
 #endif
 		case 'v':
 			printf("%s version %s\n", app_name, VERSION_STR);
-			goto out;
+			goto out_done;
 		default:
 			goto out_usage;
 		}
@@ -276,7 +280,7 @@ int main(int argc, char **argv)
 		res = errno;
 		PRINT_ERROR_PR("Unable to open file %s (%s)", dev.file_name,
 			strerror(res));
-		goto out;
+		goto out_done;
 	}
 
 	dev.file_size = lseek64(fd, 0, SEEK_END);
@@ -367,7 +371,7 @@ int main(int argc, char **argv)
 		res = dev.scst_usr_fd;
 		PRINT_ERROR_PR("Unable to open SCST device %s (%s)",
 			DEV_USER_PATH DEV_USER_NAME, strerror(res));
-		goto out;
+		goto out_done;
 	}
 
 	memset(&desc, 0, sizeof(desc));
@@ -479,10 +483,13 @@ int main(int argc, char **argv)
 out_close:
 	close(dev.scst_usr_fd);
 
+out_done:
+	debug_done();
+
 out:
 	return res;
 
 out_usage:
 	usage();
-	goto out;
+	goto out_done;
 }