From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754926AbdBPLtN (ORCPT ); Thu, 16 Feb 2017 06:49:13 -0500 Received: from mail-pf0-f195.google.com ([209.85.192.195]:34026 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932152AbdBPLqy (ORCPT ); Thu, 16 Feb 2017 06:46:54 -0500 From: Ming Lei To: Shaohua Li , Jens Axboe , linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, linux-block@vger.kernel.org, Christoph Hellwig , NeilBrown Cc: Ming Lei Subject: [PATCH 12/17] md: raid1: avoid direct access to bvec table in process_checks() Date: Thu, 16 Feb 2017 19:45:42 +0800 Message-Id: <1487245547-24384-13-git-send-email-tom.leiming@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1487245547-24384-1-git-send-email-tom.leiming@gmail.com> References: <1487245547-24384-1-git-send-email-tom.leiming@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Given process_checks is only called in resync path, it should be ok to allocate three stack variable(total 320byteds) to store pages from bios. Signed-off-by: Ming Lei --- drivers/md/raid1.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 4400fbe7ce8c..54ec32be3277 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -2010,6 +2010,9 @@ static void process_checks(struct r1bio *r1_bio) int primary; int i; int vcnt; + struct bio_vec *bi; + int page_len[RESYNC_PAGES]; + struct page *pbio_pages[RESYNC_PAGES], *sbio_pages[RESYNC_PAGES]; /* Fix variable parts of all bios */ vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9); @@ -2017,7 +2020,6 @@ static void process_checks(struct r1bio *r1_bio) int j; int size; int error; - struct bio_vec *bi; struct bio *b = r1_bio->bios[i]; if (b->bi_end_io != end_sync_read) continue; @@ -2051,6 +2053,11 @@ static void process_checks(struct r1bio *r1_bio) break; } r1_bio->read_disk = primary; + + /* .bi_vcnt has been set for all read bios */ + bio_for_each_segment_all(bi, r1_bio->bios[primary], i) + pbio_pages[i] = bi->bv_page; + for (i = 0; i < conf->raid_disks * 2; i++) { int j; struct bio *pbio = r1_bio->bios[primary]; @@ -2062,14 +2069,19 @@ static void process_checks(struct r1bio *r1_bio) /* Now we can 'fixup' the error value */ sbio->bi_error = 0; + bio_for_each_segment_all(bi, sbio, j) { + sbio_pages[j] = bi->bv_page; + page_len[j] = bi->bv_len; + } + if (!error) { for (j = vcnt; j-- ; ) { struct page *p, *s; - p = pbio->bi_io_vec[j].bv_page; - s = sbio->bi_io_vec[j].bv_page; + p = pbio_pages[j]; + s = sbio_pages[j]; if (memcmp(page_address(p), page_address(s), - sbio->bi_io_vec[j].bv_len)) + page_len[j])) break; } } else -- 2.7.4