viotape: Use unlocked_ioctl

This pushes the BKL down into the driver.  Based on a patch by Alan Cox.

We need to do it this way for now as the inode parameter of viotap_ioctl
is used internally as a flag.  We should do a further cleanup patch.

Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 18 insertions, 6 deletions

diff --git a/drivers/char/viotape.c b/drivers/char/viotape.c
index c39ddaff5e8f..d4db42ca71e6 100644
--- a/drivers/char/viotape.c
+++ b/drivers/char/viotape.c
@@ -46,6 +46,7 @@
 #include <linux/completion.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
+#include <linux/smp_lock.h>
 
 #include <asm/uaccess.h>
 #include <asm/ioctls.h>
@@ -677,6 +678,17 @@ free_op:
         return ret;
 }
 
+static long viotap_unlocked_ioctl(struct file *file,
+                unsigned int cmd, unsigned long arg)
+{
+        long rc;
+
+        lock_kernel();
+        rc = viotap_ioctl(file->f_path.dentry->d_inode, file, cmd, arg);
+        unlock_kernel();
+        return rc;
+}
+
 static int viotap_open(struct inode *inode, struct file *file)
 {
         HvLpEvent_Rc hvrc;
@@ -783,12 +795,12 @@ free_op:
 }
 
 const struct file_operations viotap_fops = {
-        .owner =        THIS_MODULE,
-        .read =         viotap_read,
-        .write =        viotap_write,
-        .ioctl =        viotap_ioctl,
-        .open =         viotap_open,
-        .release =      viotap_release,
+        .owner =                THIS_MODULE,
+        .read =                 viotap_read,
+        .write =                viotap_write,
+        .unlocked_ioctl =       viotap_unlocked_ioctl,
+        .open =                 viotap_open,
+        .release =              viotap_release,
 };
 
 /* Handle interrupt events for tape */