From patchwork Mon Jun 1 21:50:42 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 27303 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n51LtDGv026970 for ; Mon, 1 Jun 2009 21:55:14 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756756AbZFAVwX (ORCPT ); Mon, 1 Jun 2009 17:52:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756526AbZFAVwM (ORCPT ); Mon, 1 Jun 2009 17:52:12 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:35900 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754873AbZFAVvA (ORCPT ); Mon, 1 Jun 2009 17:51:00 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]) by out02.mta.xmission.com with esmtp (Exim 4.62) (envelope-from ) id 1MBFPK-0001hG-Sf; Mon, 01 Jun 2009 15:51:02 -0600 Received: from [76.21.114.89] (helo=fess.ebiederm.org) by in02.mta.xmission.com with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.69) (envelope-from ) id 1MBFPK-00048W-52; Mon, 01 Jun 2009 15:51:02 -0600 Received: from fess.ebiederm.org (localhost [127.0.0.1]) by fess.ebiederm.org (8.14.3/8.14.3/Debian-4) with ESMTP id n51LoxYC017129; Mon, 1 Jun 2009 14:50:59 -0700 Received: (from eric@localhost) by fess.ebiederm.org (8.14.3/8.14.3/Submit) id n51LoxPk017128; Mon, 1 Jun 2009 14:50:59 -0700 From: "Eric W. Biederman" To: Al Viro Cc: , , , , Hugh Dickins , Tejun Heo , Alexey Dobriyan , Linus Torvalds , Alan Cox , Greg Kroah-Hartman , Nick Piggin , Andrew Morton , Christoph Hellwig , "Eric W. Biederman" , "Eric W. Biederman" Date: Mon, 1 Jun 2009 14:50:42 -0700 Message-Id: <1243893048-17031-17-git-send-email-ebiederm@xmission.com> X-Mailer: git-send-email 1.6.3.1.54.g99dd.dirty In-Reply-To: References: X-XM-SPF: eid=; ; ; mid=; ; ; hst=in02.mta.xmission.com; ; ; ip=76.21.114.89; ; ; frm=ebiederm@xmission.com; ; ; spf=neutral X-SA-Exim-Connect-IP: 76.21.114.89 X-SA-Exim-Rcpt-To: viro@ZenIV.linux.org.uk, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, hugh@veritas.com, tj@kernel.org, adobriyan@gmail.com, torvalds@linux-foundation.org, alan@lxorguk.ukuu.org.uk, gregkh@suse.de, npiggin@suse.de, akpm@linux-foundation.org, hch@infradead.org, ebiederm@maxwell.arastra.com, ebiederm@aristanetworks.com X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-DCC: XMission; sa02 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on sa02.xmission.com X-Spam-Level: X-Spam-Status: No, score=-2.5 required=8.0 tests=ALL_TRUSTED,BAYES_00, DCC_CHECK_NEGATIVE, T_TM2_M_HEADER_IN_MSG, T_TooManySym_01, T_TooManySym_02, T_TooManySym_03, UNTRUSTED_Relay, XMNoVowels, XM_SPF_Neutral autolearn=disabled version=3.2.5 X-Spam-Combo: ;Al Viro X-Spam-Relay-Country: X-Spam-Report: * -1.8 ALL_TRUSTED Passed through trusted hosts only via SMTP * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% * [score: 0.0000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa02 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 T_TooManySym_03 6+ unique symbols in subject * 0.0 XM_SPF_Neutral SPF-Neutral * 0.0 T_TooManySym_02 5+ unique symbols in subject * 0.4 UNTRUSTED_Relay Comes from a non-trusted relay Subject: [PATCH 17/23] proc: Teach /proc//fd to use file_hotplug_lock X-SA-Exim-Version: 4.2.1 (built Thu, 25 Oct 2007 00:26:12 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Eric W. Biederman I have taken the opportunity to modify proc_fd_info to have a single exit point. Signed-off-by: Eric W. Biederman --- fs/proc/base.c | 29 ++++++++++++++++------------- 1 files changed, 16 insertions(+), 13 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index fb45615..ee4cdc2 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1626,6 +1626,7 @@ static int proc_fd_info(struct inode *inode, struct path *path, char *info) struct files_struct *files = NULL; struct file *file; int fd = proc_fd(inode); + int retval = -ENOENT; if (task) { files = get_files_struct(task); @@ -1639,24 +1640,26 @@ static int proc_fd_info(struct inode *inode, struct path *path, char *info) spin_lock(&files->file_lock); file = fcheck_files(files, fd); if (file) { - if (path) { - *path = file->f_path; - path_get(&file->f_path); + retval = -EIO; + if (file_hotplug_read_trylock(file)) { + retval = 0; + if (path) { + *path = file->f_path; + path_get(&file->f_path); + } + if (info) + snprintf(info, PROC_FDINFO_MAX, + "pos:\t%lli\n" + "flags:\t0%o\n", + (long long) file->f_pos, + file->f_flags); + file_hotplug_read_unlock(file); } - if (info) - snprintf(info, PROC_FDINFO_MAX, - "pos:\t%lli\n" - "flags:\t0%o\n", - (long long) file->f_pos, - file->f_flags); - spin_unlock(&files->file_lock); - put_files_struct(files); - return 0; } spin_unlock(&files->file_lock); put_files_struct(files); } - return -ENOENT; + return retval; } static int proc_fd_link(struct inode *inode, struct path *path)