From d79b6f4de5db0103ceb4734e42ad101d836d61d9 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Tue, 30 Mar 2010 07:27:50 +0200
Subject: procfs: Push down the bkl from ioctl

Push down the bkl from procfs's ioctl main handler to its users.
Only three procfs users implement an ioctl (non unlocked) handler.
Turn them into unlocked_ioctl and push down the Devil inside.

v2: PDE(inode)->data doesn't need to be under bkl
v3: And don't forget to git-add the result
v4: Use wrappers to pushdown instead of an invasive and error prone
    handlers surgery.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: John Kacur <jkacur@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
---
 drivers/isdn/divert/divert_procfs.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

(limited to 'drivers/isdn')

diff --git a/drivers/isdn/divert/divert_procfs.c b/drivers/isdn/divert/divert_procfs.c
index 3697c409bec6..724693c4d975 100644
--- a/drivers/isdn/divert/divert_procfs.c
+++ b/drivers/isdn/divert/divert_procfs.c
@@ -19,6 +19,7 @@
 #include <linux/sched.h>
 #include <linux/isdnif.h>
 #include <net/net_namespace.h>
+#include <linux/smp_lock.h>
 #include "isdn_divert.h"
 
 
@@ -176,9 +177,7 @@ isdn_divert_close(struct inode *ino, struct file *filep)
 /*********/
 /* IOCTL */
 /*********/
-static int
-isdn_divert_ioctl(struct inode *inode, struct file *file,
-		  uint cmd, ulong arg)
+static int isdn_divert_ioctl_unlocked(struct file *file, uint cmd, ulong arg)
 {
 	divert_ioctl dioctl;
 	int i;
@@ -257,6 +256,17 @@ isdn_divert_ioctl(struct inode *inode, struct file *file,
 	return copy_to_user((void __user *)arg, &dioctl, sizeof(dioctl)) ? -EFAULT : 0;
 }				/* isdn_divert_ioctl */
 
+static long isdn_divert_ioctl(struct file *file, uint cmd, ulong arg)
+{
+	long ret;
+
+	lock_kernel();
+	ret = isdn_divert_ioctl_unlocked(file, cmd, arg);
+	unlock_kernel();
+
+	return ret;
+}
+
 static const struct file_operations isdn_fops =
 {
 	.owner          = THIS_MODULE,
@@ -264,7 +274,7 @@ static const struct file_operations isdn_fops =
 	.read           = isdn_divert_read,
 	.write          = isdn_divert_write,
 	.poll           = isdn_divert_poll,
-	.ioctl          = isdn_divert_ioctl,
+	.unlocked_ioctl = isdn_divert_ioctl,
 	.open           = isdn_divert_open,
 	.release        = isdn_divert_close,                                      
 };
-- 
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