From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 29 Jul 2016 11:46:08 +0200 (CEST) From: Sebastian Ott Subject: Re: [PATCH] s390/pci: Remove unnecessary if condition In-Reply-To: References: <20160729083150.GA8819@amitoj-Inspiron-3542> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Message-Id: Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Julia Lawall Cc: Amitoj Kaur Chawla , Gerald Schaefer , Martin Schwidefsky , Heiko Carstens , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org List-ID: On Fri, 29 Jul 2016, Julia Lawall wrote: > On Fri, 29 Jul 2016, Sebastian Ott wrote: > > On Fri, 29 Jul 2016, Amitoj Kaur Chawla wrote: > > > Remove unnecessary error handling because the only failure value that > > > can be returned is NULL and so the test can never be true. > > > > > > The Coccinelle semantic patch used to make this change is as follows: > > > @@ > > > expression e; > > > @@ > > > > > > e = debugfs_create_file(...); > > > - if(IS_ERR(e)) { e = NULL; } > > > > Nope. For !CONFIG_DEBUG_FS debugfs_create_file returns an ERR_PTR. > > Clicking around in lxr doesn't show that, but perhaps an alternative > definition is overlooked? It looks that way. [sebott@schleppi linux]$ git grep -W "debugfs_create_file(" include/linux/debugfs.h include/linux/debugfs.h:struct dentry *debugfs_create_file(const char *name, umode_t mode, include/linux/debugfs.h- struct dentry *parent, void *data, include/linux/debugfs.h- const struct file_operations *fops); -- include/linux/debugfs.h:static inline struct dentry *debugfs_create_file(const char *name, umode_t mode, include/linux/debugfs.h- struct dentry *parent, void *data, include/linux/debugfs.h- const struct file_operations *fops) include/linux/debugfs.h-{ include/linux/debugfs.h- return ERR_PTR(-ENODEV); include/linux/debugfs.h-} include/linux/debugfs.h- Regards, Sebastian