From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760207Ab1FXBsb (ORCPT ); Thu, 23 Jun 2011 21:48:31 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:42513 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760005Ab1FXBsa (ORCPT ); Thu, 23 Jun 2011 21:48:30 -0400 X-SecurityPolicyCheck-FJ: OK by FUJITSU ADVANCED ENGINEERING MailBarrier Date: Fri, 24 Jun 2011 10:48:08 +0900 From: =?ISO-2022-JP?B?IkZKQ0wpIBskQjIuTG4bKEIgGyRCQmdKZRsoQg==?= =?ISO-2022-JP?B?Ig==?= To: linux-kernel@vger.kernel.org Subject: [patch] procfs: returns ENOENT on opening the being-removed proc entry Cc: linux-pci@vger.kernel.org, adobriyan@gmail.com Message-Id: <20110624104509.6195.371AB99A@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50 [ja] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Daisuke Ohino opening the proc entry may return EINVAL if the entry is being removed, for example open("/proc/bus/pci/XX/YY") during the corresponding device is being hot-removed. The return value is inappropriate and should return ENOENT. This return value comes from proc_reg_open(). fs/proc/inode.c: ----------------------------------------------------------- static int proc_reg_open(struct inode *inode, struct file *file) { (snip) if (!pde->proc_fops) { spin_unlock(&pde->pde_unload_lock); kfree(pdeo); return -EINVAL; } (snip) ----------------------------------------------------------- pde->proc_fops is NULL iff the proc entry is being removed. It is set by remove_proc_entry(). ----------------------------------------------------------- void remove_proc_entry(const char *name, struct proc_dir_entry*parent) { (snip) /* * Stop accepting new callers into module. If you're * dynamically allocating ->proc_fops, save a pointer somewhere. */ de->proc_fops = NULL; (snip) ----------------------------------------------------------- But POSIX says: ----------------------------------------------------------- [EINVAL] The implementation does not support synchronized I/O for this file. ----------------------------------------------------------- Since removing proc entry is apparently not related to synchronized I/O, this function should return ENOENT in this case. Signed-off-by: Daisuke Ogino --- fs/proc/inode.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/fs/proc/inode.c b/fs/proc/inode.c index 74b48cf..7ed72d6 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -319,7 +319,7 @@ static int proc_reg_open(struct inode *inode, struct file *file) if (!pde->proc_fops) { spin_unlock(&pde->pde_unload_lock); kfree(pdeo); - return -EINVAL; + return -ENOENT; } pde->pde_users++; open = pde->proc_fops->open; -- Since I don't subscribe LKML, please Cc me if you have any comment. Thanks, Daisuke