changer: BKL pushdown

Add lock_kernel() calls to ch_open(), though the existing locking looks
adequate.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --git a/drivers/scsi/ch.c b/drivers/scsi/ch.c
index 75c84d7..8e821be 100644 (file)
--- a/drivers/scsi/ch.c
+++ b/drivers/scsi/ch.c
@@ -22,6 +22,7 @@
 #include <linux/chio.h>                        /* here are all the ioctls */
 #include <linux/mutex.h>
 #include <linux/idr.h>
+#include <linux/smp_lock.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
@@ -571,16 +572,19 @@ ch_open(struct inode *inode, struct file *file)
        scsi_changer *ch;
        int minor = iminor(inode);
 
+       lock_kernel();
        spin_lock(&ch_index_lock);
        ch = idr_find(&ch_index_idr, minor);
 
        if (NULL == ch || scsi_device_get(ch->device)) {
                spin_unlock(&ch_index_lock);
+               unlock_kernel();
                return -ENXIO;
        }
        spin_unlock(&ch_index_lock);
 
        file->private_data = ch;
+       unlock_kernel();
        return 0;
 }