From patchwork Tue Apr 8 20:42:49 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josh Durgin X-Patchwork-Id: 3951351 Return-Path: X-Original-To: patchwork-ceph-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 0DDD89F370 for ; Tue, 8 Apr 2014 22:03:13 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 36634204AF for ; Tue, 8 Apr 2014 22:03:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 569592025B for ; Tue, 8 Apr 2014 22:03:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757466AbaDHWCy (ORCPT ); Tue, 8 Apr 2014 18:02:54 -0400 Received: from mail.hq.newdream.net ([66.33.206.127]:56383 "EHLO mail.hq.newdream.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756235AbaDHWC0 (ORCPT ); Tue, 8 Apr 2014 18:02:26 -0400 Received: from mail.hq.newdream.net (localhost [127.0.0.1]) by mail.hq.newdream.net (Postfix) with ESMTP id BC899267DB for ; Tue, 8 Apr 2014 14:52:31 -0700 (PDT) Received: from vit.ops.newdream.net (unknown [38.122.20.226]) by mail.hq.newdream.net (Postfix) with ESMTPSA id B4781267BC for ; Tue, 8 Apr 2014 14:52:31 -0700 (PDT) From: Josh Durgin To: ceph-devel@vger.kernel.org Subject: [PATCH 05/11] rbd: read image size for discard check safely Date: Tue, 8 Apr 2014 13:42:49 -0700 Message-Id: <7376321311dedcd90e7f16ab1a94cb2c4f34786f.1396987789.git.josh.durgin@inktank.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: References: In-Reply-To: References: Sender: ceph-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org X-Spam-Status: No, score=-7.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, 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 In rbd_img_request_fill() the image size is only checked to determine whether we can truncate an object instead of zeroing it for discard requests. Take rbd_dev->header_rwsem while reading the image size, and move this read into the discard check, so that non-discard ops don't need to take the semaphore in this function. Signed-off-by: Josh Durgin --- drivers/block/rbd.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 9dc33d9..486e4b5 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -2235,7 +2235,6 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request, (int)type, data_desc); img_offset = img_request->offset; - img_end = rbd_dev->header.image_size; resid = img_request->length; rbd_assert(resid > 0); @@ -2300,13 +2299,20 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request, if (!offset && (length == object_size) && (!img_request_layered_test(img_request) || (rbd_dev->parent_overlap <= - obj_request->img_offset))) + obj_request->img_offset))) { opcode = CEPH_OSD_OP_DELETE; - else if ((offset + length == object_size) || - (obj_request->img_offset + length == img_end)) + } else if ((offset + length == object_size)) { opcode = CEPH_OSD_OP_TRUNCATE; - else - opcode = CEPH_OSD_OP_ZERO; + } else { + down_read(&rbd_dev->header_rwsem); + img_end = rbd_dev->header.image_size; + up_read(&rbd_dev->header_rwsem); + + if (obj_request->img_offset + length == img_end) + opcode = CEPH_OSD_OP_TRUNCATE; + else + opcode = CEPH_OSD_OP_ZERO; + } } else if (img_request_write_test(img_request)) { op_type = OBJ_OP_WRITE; opcode = CEPH_OSD_OP_WRITE;