From patchwork Fri Jun 10 01:30:59 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trond Myklebust X-Patchwork-Id: 867722 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p5A1VKPM014497 for ; Fri, 10 Jun 2011 01:31:22 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757557Ab1FJBbQ (ORCPT ); Thu, 9 Jun 2011 21:31:16 -0400 Received: from mx2.netapp.com ([216.240.18.37]:5591 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756921Ab1FJBbI (ORCPT ); Thu, 9 Jun 2011 21:31:08 -0400 X-IronPort-AV: E=Sophos;i="4.65,344,1304319600"; d="scan'208";a="554451075" Received: from smtp1.corp.netapp.com ([10.57.156.124]) by mx2-out.netapp.com with ESMTP; 09 Jun 2011 18:30:52 -0700 Received: from lade.trondhjem.org.com ([10.55.68.90]) by smtp1.corp.netapp.com (8.13.1/8.13.1/NTAP-1.6) with ESMTP id p5A1Uq6B015723; Thu, 9 Jun 2011 18:30:52 -0700 (PDT) From: Trond Myklebust To: linux-nfs@vger.kernel.org Subject: [PATCH 2/5] NFSv4.1: Fix an off-by-one error in pnfs_generic_pg_test Date: Thu, 9 Jun 2011 21:30:59 -0400 Message-Id: <1307669462-15764-2-git-send-email-Trond.Myklebust@netapp.com> X-Mailer: git-send-email 1.7.5.2 In-Reply-To: <1307669462-15764-1-git-send-email-Trond.Myklebust@netapp.com> References: <1307669462-15764-1-git-send-email-Trond.Myklebust@netapp.com> Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Fri, 10 Jun 2011 01:31:22 +0000 (UTC) And document what is going on there... Signed-off-by: Trond Myklebust --- fs/nfs/pnfs.c | 21 ++++++++++++++++----- 1 files changed, 16 insertions(+), 5 deletions(-) diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index 12b53ef..9a4ce7c 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -1073,11 +1073,22 @@ pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev, return true; } - if (req_offset(req) > end_offset(pgio->pg_lseg->pls_range.offset, - pgio->pg_lseg->pls_range.length)) - return false; - - return true; + /* + * Test if a nfs_page is fully contained in the pnfs_layout_range. + * Note that this test makes several assumptions: + * - that the previous nfs_page in the struct nfs_pageio_descriptor + * is known to lie within the range. + * - that the nfs_page being tested is known to be contiguous with the + * previous nfs_page. + * - Layout ranges are page aligned, so we only have to test the + * start offset of the request. + * + * Please also note that 'end_offset' is actually the offset of the + * first byte that lies outside the pnfs_layout_range. FIXME? + * + */ + return req_offset(req) < end_offset(pgio->pg_lseg->pls_range.offset, + pgio->pg_lseg->pls_range.length); } EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);