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net: Remove BKL from tun 

The lock_kernel/unlock_kernel() in cycle_kernel_lock() which is called
in tun_chr_open() is not serializing against anything and safe to
remove.

tun_chr_fasync() is serialized by get/put_tun() and fasync_helper()
has no dependency on BKL. The modification of tun->flags is racy with
and without the BKL so removing it does not make it worse.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Thomas Gleixner 2009-10-14 01:19:46 -07:00 committed by David S. Miller
parent 421355de87
commit deed49fbb6
1 changed files with 1 additions and 4 deletions
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5
drivers/net/tun.c
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@ -44,7 +44,6 @@
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/poll.h>
#include <linux/fcntl.h>
#include <linux/init.h>
@ -1285,7 +1284,6 @@ static int tun_chr_fasync(int fd, struct file *file, int on)
DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on);
lock_kernel();
if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0)
goto out;
@ -1298,7 +1296,6 @@ static int tun_chr_fasync(int fd, struct file *file, int on)
tun->flags &= ~TUN_FASYNC;
ret = 0;
out:
unlock_kernel();
tun_put(tun);
return ret;
}
@ -1306,7 +1303,7 @@ static int tun_chr_fasync(int fd, struct file *file, int on)
static int tun_chr_open(struct inode *inode, struct file * file)
{
struct tun_file *tfile;
cycle_kernel_lock();
DBG1(KERN_INFO "tunX: tun_chr_open\n");
tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);