1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/s390/char/fs3270.c b/drivers/s390/char/fs3270.c
index 097d3846a828..d449063c30fe 100644
--- a/drivers/s390/char/fs3270.c
+++ b/drivers/s390/char/fs3270.c
@@ -38,6 +38,8 @@ struct fs3270 {
         size_t rdbuf_size;              /* size of data returned by RDBUF */
 };
 
+static DEFINE_MUTEX(fs3270_mutex);
+
 static void
 fs3270_wake_up(struct raw3270_request *rq, void *data)
 {
@@ -328,7 +330,7 @@ fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
         if (!fp)
                 return -ENODEV;
         rc = 0;
-        lock_kernel();
+        mutex_lock(&fs3270_mutex);
         switch (cmd) {
         case TUBICMD:
                 fp->read_command = arg;
@@ -354,7 +356,7 @@ fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
                         rc = -EFAULT;
                 break;
         }
-        unlock_kernel();
+        mutex_unlock(&fs3270_mutex);
         return rc;
 }
 
@@ -437,7 +439,7 @@ fs3270_open(struct inode *inode, struct file *filp)
                 minor = tty->index + RAW3270_FIRSTMINOR;
                 tty_kref_put(tty);
         }
-        lock_kernel();
+        mutex_lock(&fs3270_mutex);
         /* Check if some other program is already using fullscreen mode. */
         fp = (struct fs3270 *) raw3270_find_view(&fs3270_fn, minor);
         if (!IS_ERR(fp)) {
@@ -478,7 +480,7 @@ fs3270_open(struct inode *inode, struct file *filp)
         }
         filp->private_data = fp;
 out:
-        unlock_kernel();
+        mutex_unlock(&fs3270_mutex);
         return rc;
 }