wrappers for ->i_mutex access

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/security/inode.c b/security/inode.c
index 16622ae..28414b0 100644
--- a/security/inode.c
+++ b/security/inode.c
@@ -99,7 +99,7 @@
 
 	dir = d_inode(parent);
 
-	mutex_lock(&dir->i_mutex);
+	inode_lock(dir);
 	dentry = lookup_one_len(name, parent, strlen(name));
 	if (IS_ERR(dentry))
 		goto out;
@@ -129,14 +129,14 @@
 	}
 	d_instantiate(dentry, inode);
 	dget(dentry);
-	mutex_unlock(&dir->i_mutex);
+	inode_unlock(dir);
 	return dentry;
 
 out1:
 	dput(dentry);
 	dentry = ERR_PTR(error);
 out:
-	mutex_unlock(&dir->i_mutex);
+	inode_unlock(dir);
 	simple_release_fs(&mount, &mount_count);
 	return dentry;
 }
@@ -195,7 +195,7 @@
 	if (!parent || d_really_is_negative(parent))
 		return;
 
-	mutex_lock(&d_inode(parent)->i_mutex);
+	inode_lock(d_inode(parent));
 	if (simple_positive(dentry)) {
 		if (d_is_dir(dentry))
 			simple_rmdir(d_inode(parent), dentry);
@@ -203,7 +203,7 @@
 			simple_unlink(d_inode(parent), dentry);
 		dput(dentry);
 	}
-	mutex_unlock(&d_inode(parent)->i_mutex);
+	inode_unlock(d_inode(parent));
 	simple_release_fs(&mount, &mount_count);
 }
 EXPORT_SYMBOL_GPL(securityfs_remove);