1 files changed, 16 insertions, 6 deletions

diff --git a/drivers/net/wan/cosa.c b/drivers/net/wan/cosa.c
index b0fce1387eaf..5827324e9d9f 100644
--- a/drivers/net/wan/cosa.c
+++ b/drivers/net/wan/cosa.c
@@ -92,6 +92,7 @@
 #include <linux/spinlock.h>
 #include <linux/mutex.h>
 #include <linux/device.h>
+#include <linux/smp_lock.h>
 
 #undef COSA_SLOW_IO     /* for testing purposes only */
 
@@ -970,15 +971,21 @@ static int cosa_open(struct inode *inode, struct file *file)
         struct channel_data *chan;
         unsigned long flags;
         int n;
+        int ret = 0;
 
+        lock_kernel();
         if ((n=iminor(file->f_path.dentry->d_inode)>>CARD_MINOR_BITS)
-                >= nr_cards)
-                return -ENODEV;
+                >= nr_cards) {
+                ret = -ENODEV;
+                goto out;
+        }
         cosa = cosa_cards+n;
 
         if ((n=iminor(file->f_path.dentry->d_inode)
-                & ((1<<CARD_MINOR_BITS)-1)) >= cosa->nchannels)
-                return -ENODEV;
+                & ((1<<CARD_MINOR_BITS)-1)) >= cosa->nchannels) {
+                ret = -ENODEV;
+                goto out;
+        }
         chan = cosa->chan + n;
         
         file->private_data = chan;
@@ -987,7 +994,8 @@ static int cosa_open(struct inode *inode, struct file *file)
 
         if (chan->usage < 0) { /* in netdev mode */
                 spin_unlock_irqrestore(&cosa->lock, flags);
-                return -EBUSY;
+                ret = -EBUSY;
+                goto out;
         }
         cosa->usage++;
         chan->usage++;
@@ -996,7 +1004,9 @@ static int cosa_open(struct inode *inode, struct file *file)
         chan->setup_rx = chrdev_setup_rx;
         chan->rx_done = chrdev_rx_done;
         spin_unlock_irqrestore(&cosa->lock, flags);
-        return 0;
+out:
+        unlock_kernel();
+        return ret;
 }
 
 static int cosa_release(struct inode *inode, struct file *file)