From patchwork Tue May 5 03:53:27 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kinglong Mee X-Patchwork-Id: 6333791 Return-Path: X-Original-To: patchwork-linux-nfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 45FED9F373 for ; Tue, 5 May 2015 03:53:38 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 4E92920225 for ; Tue, 5 May 2015 03:53:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5F87F20221 for ; Tue, 5 May 2015 03:53:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755210AbbEEDxf (ORCPT ); Mon, 4 May 2015 23:53:35 -0400 Received: from mail-pd0-f176.google.com ([209.85.192.176]:35465 "EHLO mail-pd0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755030AbbEEDxe (ORCPT ); Mon, 4 May 2015 23:53:34 -0400 Received: by pdbqd1 with SMTP id qd1so181874064pdb.2 for ; Mon, 04 May 2015 20:53:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=+HdpkdLZaXcuT1NhRYdLV3jUqJEcab9VKPGqeAvDCaw=; b=nmutlc5DJtxCunAe8MOkKpj7pWXoDnuVgqFQxBC7/pIJg4yqijITnkyTPvRsEYaIzn Hq1izs9JGpHLA2kYpMXsDzKzQK9+IA8GdxSeyQiBGcSJ1g/TK5nA/bJVadVJvaGdMTj4 Xvdz2tiPSSPaGYQO1zcDOUPHFVSl8soiL3Wswc0FCnoCXjxtrOulCl9gcg05LwFc/AG3 /U1W44g9DoDhvU5E6046GXoYZhCabHL0VHpJymIKlREr4kD41Cr9/YXQeEH8827ERMbU 6D1btuvHjzP/MZIjF0/6SEV9jzx74s1DJra0Ip138aZ/n6emVv2zH+2IHhcLHqrgzI7d ruqg== X-Received: by 10.70.49.35 with SMTP id r3mr49016349pdn.22.1430798013701; Mon, 04 May 2015 20:53:33 -0700 (PDT) Received: from [192.168.99.23] ([104.143.41.79]) by mx.google.com with ESMTPSA id cy5sm14269486pdb.85.2015.05.04.20.53.30 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 04 May 2015 20:53:32 -0700 (PDT) Message-ID: <55483EB7.5060104@gmail.com> Date: Tue, 05 May 2015 11:53:27 +0800 From: Kinglong Mee User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: "J. Bruce Fields" , NeilBrown CC: "linux-nfs@vger.kernel.org" , Al Viro , kinglongmee@gmail.com, Steve Dickson Subject: Re: [PATCH RFC] NFSD: fix cannot umounting mount points under pseudo root References: <20150421215417.GE13782@fieldses.org> <553781E2.1000900@gmail.com> <20150422150703.GA1247@fieldses.org> <20150423094431.1a8aa68b@notabene.brown> <5538EB18.7080802@gmail.com> <20150424130045.6bbdb2f9@notabene.brown> <553E2784.6020906@gmail.com> <20150429125728.69ddfc6c@notabene.brown> <20150429191934.GA23980@fieldses.org> <20150430075225.21a71056@notabene.brown> <20150430213602.GB9509@fieldses.org> In-Reply-To: <20150430213602.GB9509@fieldses.org> Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Spam-Status: No, score=-6.8 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, T_DKIM_INVALID, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Cc Steve, Viro, On 5/1/2015 5:36 AM, J. Bruce Fields wrote: > On Thu, Apr 30, 2015 at 07:52:25AM +1000, NeilBrown wrote: >> On Wed, 29 Apr 2015 15:19:34 -0400 "J. Bruce Fields" >> wrote: >>> Maybe drop the locking from nfsd_buffered_readdir and *just* take the >>> i_mutex around lookup_one_len(), if that's the only place we need it? As description in other thread, before the upcall to rpc.mountd, nfsd have call lookup_one_len() for the file, but why rpc.mountd also blocked in lookup ? There is a bug in rpc.mountd when checking sub-directory, it sets bad patch length for child. If parent if "/nfs/xfs" and child is "/nfs/test", the child name will be truncated to "/nfs/tes" for strlen(parent), "/nfs/test" have exist in kernel's cache for the lookup_one_len(), but "/nfs/tes" is a bad path, which needs lookup_slow(), so blocked. static int is_subdirectory(char *child, char *parent) { /* Check is child is strictly a subdirectory of * parent or a more distant descendant. */ size_t l = strlen(parent); if (strcmp(parent, "/") == 0 && child[1] != 0) return 1; return (same_path(child, parent, l) && child[l] == '/'); } The following path makes a correct path, not a truncated path. Have be tested, everything is OK. thanks, Kinglong Mee ----------------------------------------------------------------------------------- From 70b9d1d93a24db8a7837998cb7eb0ff4e98480a6 Mon Sep 17 00:00:00 2001 From: Kinglong Mee Date: Tue, 5 May 2015 11:47:20 +0800 Subject: [PATCH] mountd: Case-insensitive path length must equal to parent Commit 6091c0a4c4 (mountd: add support for case-insensitive file names) introdues a bug cause mutex race when looking bad path. Signed-off-by: Kinglong Mee --- utils/mountd/cache.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c index 7d250f9..9d9a1bb 100644 --- a/utils/mountd/cache.c +++ b/utils/mountd/cache.c @@ -468,16 +468,36 @@ fallback: return 1; } +static int subdir_len(char *name, int count_slashes) +{ + char *ptr = NULL; + int i; + + ptr = name; + for (i = 0; i < count_slashes + 1; i++) { + ptr = strchr(ptr, '/'); + if (NULL == ptr) + return strlen(name); + ptr++; + } + + return ptr - name; +} + static int is_subdirectory(char *child, char *parent) { /* Check is child is strictly a subdirectory of * parent or a more distant descendant. */ - size_t l = strlen(parent); + size_t l = subdir_len(child, count_slashes(parent)); if (strcmp(parent, "/") == 0 && child[1] != 0) return 1; + /* Case-insensitive path length must equal to parent */ + if (l != strlen(parent)) + return 0; + return (same_path(child, parent, l) && child[l] == '/'); }