[S390] monwriter: remove lock_kernel() from open() function

The lock_kernel() calls in the open() function are unnecessary because
misc_register() is called last in module_init() and concurrent open()
calls are handled by other means.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/char/monwriter.c b/drivers/s390/char/monwriter.c
index 66fb8eba93f43bfe16d03784dbc21eac52b78f78..6532ed8b4afad0a75a2fef4037eb86c121e3f659 100644 (file)
--- a/drivers/s390/char/monwriter.c
+++ b/drivers/s390/char/monwriter.c
@@ -13,7 +13,6 @@
 #include <linux/moduleparam.h>
 #include <linux/init.h>
 #include <linux/errno.h>
-#include <linux/smp_lock.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/miscdevice.h>
@@ -185,13 +184,11 @@ static int monwrite_open(struct inode *inode, struct file *filp)
        monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL);
        if (!monpriv)
                return -ENOMEM;
-       lock_kernel();
        INIT_LIST_HEAD(&monpriv->list);
        monpriv->hdr_to_read = sizeof(monpriv->hdr);
        mutex_init(&monpriv->thread_mutex);
        filp->private_data = monpriv;
        list_add_tail(&monpriv->priv_list, &mon_priv_list);
-       unlock_kernel();
        return nonseekable_open(inode, filp);
 }
 
@@ -364,6 +361,10 @@ static int __init mon_init(void)
                goto out_driver;
        }
 
+       /*
+        * misc_register() has to be the last action in module_init(), because
+        * file operations will be available right after this.
+        */
        rc = misc_register(&mon_dev);
        if (rc)
                goto out_device;