From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757839Ab3KNQu4 (ORCPT ); Thu, 14 Nov 2013 11:50:56 -0500 Received: from mail-pa0-f45.google.com ([209.85.220.45]:37696 "EHLO mail-pa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756637Ab3KNQnj (ORCPT ); Thu, 14 Nov 2013 11:43:39 -0500 From: Peng Tao To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, Sebastien Buisson , Peng Tao , Andreas Dilger Subject: [PATCH 02/26] staging/lustre/build: fix race issues thanks to oap_lock Date: Fri, 15 Nov 2013 00:42:49 +0800 Message-Id: <1384447393-13838-3-git-send-email-bergwolf@gmail.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1384447393-13838-1-git-send-email-bergwolf@gmail.com> References: <1384447393-13838-1-git-send-email-bergwolf@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sebastien Buisson Fix 'data race condition' defects found by Coverity version 6.5.0: Data race condition (MISSING_LOCK) Accessing variable without holding lock. Elsewhere, this variable is accessed with lock held. This patch is dedicated to code fragments involving oap_lock. Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-2744 Lustre-change: http://review.whamcloud.com/6572 Signed-off-by: Sebastien Buisson Reviewed-by: Oleg Drokin Reviewed-by: Andreas Dilger Signed-off-by: Peng Tao Signed-off-by: Andreas Dilger --- drivers/staging/lustre/lustre/osc/osc_cache.c | 6 ++++++ drivers/staging/lustre/lustre/osc/osc_io.c | 2 ++ 2 files changed, 8 insertions(+) diff --git a/drivers/staging/lustre/lustre/osc/osc_cache.c b/drivers/staging/lustre/lustre/osc/osc_cache.c index abb4604..ff36e77 100644 --- a/drivers/staging/lustre/lustre/osc/osc_cache.c +++ b/drivers/staging/lustre/lustre/osc/osc_cache.c @@ -1071,7 +1071,9 @@ static int osc_extent_make_ready(const struct lu_env *env, last->oap_count = osc_refresh_count(env, last, OBD_BRW_WRITE); LASSERT(last->oap_count > 0); LASSERT(last->oap_page_off + last->oap_count <= PAGE_CACHE_SIZE); + spin_lock(&last->oap_lock); last->oap_async_flags |= ASYNC_COUNT_STABLE; + spin_unlock(&last->oap_lock); } /* for the rest of pages, we don't need to call osf_refresh_count() @@ -1079,7 +1081,9 @@ static int osc_extent_make_ready(const struct lu_env *env, list_for_each_entry(oap, &ext->oe_pages, oap_pending_item) { if (!(oap->oap_async_flags & ASYNC_COUNT_STABLE)) { oap->oap_count = PAGE_CACHE_SIZE - oap->oap_page_off; + spin_lock(&oap->oap_lock); oap->oap_async_flags |= ASYNC_COUNT_STABLE; + spin_unlock(&oap->oap_lock); } } @@ -2238,6 +2242,8 @@ int osc_queue_async_io(const struct lu_env *env, struct cl_io *io, oap->oap_cmd = cmd; oap->oap_page_off = ops->ops_from; oap->oap_count = ops->ops_to - ops->ops_from; + /* No need to hold a lock here, + * since this page is not in any list yet. */ oap->oap_async_flags = 0; oap->oap_brw_flags = brw_flags; diff --git a/drivers/staging/lustre/lustre/osc/osc_io.c b/drivers/staging/lustre/lustre/osc/osc_io.c index e567f2f..d464243 100644 --- a/drivers/staging/lustre/lustre/osc/osc_io.c +++ b/drivers/staging/lustre/lustre/osc/osc_io.c @@ -164,8 +164,10 @@ static int osc_io_submit(const struct lu_env *env, } cl_page_list_move(qout, qin, page); + spin_lock(&oap->oap_lock); oap->oap_async_flags = ASYNC_URGENT|ASYNC_READY; oap->oap_async_flags |= ASYNC_COUNT_STABLE; + spin_unlock(&oap->oap_lock); osc_page_submit(env, opg, crt, brw_flags); list_add_tail(&oap->oap_pending_item, &list); -- 1.7.9.5