BKL: Remove BKL from autofs4

autofs4 uses the BKL only to guard its ioctl operations.
This can be trivially converted to use a mutex, as we have
done with most device drivers before.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ian Kent <raven@themaw.net>

diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index cb1bd38dc08cb10c47650e1e08c2a8fe13730ab2..9dd29c29fd12dd95f7b6155d83ddf0c24d1f6495 100644 (file)
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -19,7 +19,7 @@
 #include <linux/param.h>
 #include <linux/time.h>
 #include <linux/compat.h>
-#include <linux/smp_lock.h>
+#include <linux/mutex.h>
 
 #include "autofs_i.h"
 
@@ -978,15 +978,17 @@ static int autofs4_root_ioctl_unlocked(struct inode *inode, struct file *filp,
        }
 }
 
+static DEFINE_MUTEX(autofs4_ioctl_mutex);
+
 static long autofs4_root_ioctl(struct file *filp,
                               unsigned int cmd, unsigned long arg)
 {
        long ret;
        struct inode *inode = filp->f_dentry->d_inode;
 
-       lock_kernel();
+       mutex_lock(&autofs4_ioctl_mutex);
        ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg);
-       unlock_kernel();
+       mutex_unlock(&autofs4_ioctl_mutex);
 
        return ret;
 }
@@ -998,13 +1000,13 @@ static long autofs4_root_compat_ioctl(struct file *filp,
        struct inode *inode = filp->f_path.dentry->d_inode;
        int ret;
 
-       lock_kernel();
+       mutex_lock(&autofs4_ioctl_mutex);
        if (cmd == AUTOFS_IOC_READY || cmd == AUTOFS_IOC_FAIL)
                ret = autofs4_root_ioctl_unlocked(inode, filp, cmd, arg);
        else
                ret = autofs4_root_ioctl_unlocked(inode, filp, cmd,
                        (unsigned long)compat_ptr(arg));
-       unlock_kernel();
+       mutex_unlock(&autofs4_ioctl_mutex);
 
        return ret;
 }