binderfs: drop lock in binderfs_binder_ctl_create

The binderfs_binder_ctl_create() call is a no-op on subsequent calls and
the first call is done before we unlock the suberblock. Hence, there is no
need to take inode_lock() in there. Let's remove it.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christian Brauner <christian@brauner.io>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c
index ba88be1..d537dcd 100644 (file)
--- a/drivers/android/binderfs.c
+++ b/drivers/android/binderfs.c
@@ -400,8 +400,6 @@ static int binderfs_binder_ctl_create(struct super_block *sb)
        if (!device)
                return -ENOMEM;
 
-       inode_lock(d_inode(root));
-
        /* If we have already created a binder-control node, return. */
        if (info->control_dentry) {
                ret = 0;
@@ -440,12 +438,10 @@ static int binderfs_binder_ctl_create(struct super_block *sb)
        inode->i_private = device;
        info->control_dentry = dentry;
        d_add(dentry, inode);
-       inode_unlock(d_inode(root));
 
        return 0;
 
 out:
-       inode_unlock(d_inode(root));
        kfree(device);
        iput(inode);