From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9FC8DC432C3 for ; Tue, 3 Dec 2019 22:51:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 66D9B2053B for ; Tue, 3 Dec 2019 22:51:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575413490; bh=FsaOr/rO8jZIyV6MliQ60rSwoFVaHYrbJ/cX0U66GDM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=pn5VWwzlimtGB+K3Dm/uiQ4SCUrTM/mod+RqKHd2jsZsKa1XcDFzr6o6XKYj0i0j3 zSku9bm1vDvg9Tvp14emDkOE8AO6otM1smJJfymhiI9ZnLBXfYg7Y8YtSQ02vAgUdJ QQwQMii+nhCBLpGCxw0YUdfKBkUv4vIW+KJXpPUk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729895AbfLCWv1 (ORCPT ); Tue, 3 Dec 2019 17:51:27 -0500 Received: from mail.kernel.org ([198.145.29.99]:43424 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729866AbfLCWvT (ORCPT ); Tue, 3 Dec 2019 17:51:19 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 08D6720881; Tue, 3 Dec 2019 22:51:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575413478; bh=FsaOr/rO8jZIyV6MliQ60rSwoFVaHYrbJ/cX0U66GDM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EfUPkeeR8T23276EDGk+rLtevw88x8CofOfYgdn5APF60qtwuN6QgoyvEpzQ4GqMk 1M1Li8DdmM9eD24AfpIUgGcGNuLoE3V9on7GrBGoKk8JnoklcJZdT5Ha29+Cr5w+9d F/wT+dge/chaXzhHdrTQvi2vR16VxmfjEGM+6vyo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, John Dorminy , Mike Snitzer , Sasha Levin Subject: [PATCH 4.19 144/321] dm flakey: Properly corrupt multi-page bios. Date: Tue, 3 Dec 2019 23:33:30 +0100 Message-Id: <20191203223434.648403089@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191203223427.103571230@linuxfoundation.org> References: <20191203223427.103571230@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sweet Tea [ Upstream commit a00f5276e26636cbf72f24f79831026d2e2868e7 ] The flakey target is documented to be able to corrupt the Nth byte in a bio, but does not corrupt byte indices after the first biovec in the bio. Change the corrupting function to actually corrupt the Nth byte no matter in which biovec that index falls. A test device generating two-page bios, atop a flakey device configured to corrupt a byte index on the second page, verified both the failure to corrupt before this patch and the expected corruption after this change. Signed-off-by: John Dorminy Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin --- drivers/md/dm-flakey.c | 33 ++++++++++++++++++++++----------- 1 file changed, 22 insertions(+), 11 deletions(-) diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c index b86d2439ffc76..2fcf62fb2844f 100644 --- a/drivers/md/dm-flakey.c +++ b/drivers/md/dm-flakey.c @@ -287,20 +287,31 @@ static void flakey_map_bio(struct dm_target *ti, struct bio *bio) static void corrupt_bio_data(struct bio *bio, struct flakey_c *fc) { - unsigned bio_bytes = bio_cur_bytes(bio); - char *data = bio_data(bio); + unsigned int corrupt_bio_byte = fc->corrupt_bio_byte - 1; + + struct bvec_iter iter; + struct bio_vec bvec; + + if (!bio_has_data(bio)) + return; /* - * Overwrite the Nth byte of the data returned. + * Overwrite the Nth byte of the bio's data, on whichever page + * it falls. */ - if (data && bio_bytes >= fc->corrupt_bio_byte) { - data[fc->corrupt_bio_byte - 1] = fc->corrupt_bio_value; - - DMDEBUG("Corrupting data bio=%p by writing %u to byte %u " - "(rw=%c bi_opf=%u bi_sector=%llu cur_bytes=%u)\n", - bio, fc->corrupt_bio_value, fc->corrupt_bio_byte, - (bio_data_dir(bio) == WRITE) ? 'w' : 'r', bio->bi_opf, - (unsigned long long)bio->bi_iter.bi_sector, bio_bytes); + bio_for_each_segment(bvec, bio, iter) { + if (bio_iter_len(bio, iter) > corrupt_bio_byte) { + char *segment = (page_address(bio_iter_page(bio, iter)) + + bio_iter_offset(bio, iter)); + segment[corrupt_bio_byte] = fc->corrupt_bio_value; + DMDEBUG("Corrupting data bio=%p by writing %u to byte %u " + "(rw=%c bi_opf=%u bi_sector=%llu size=%u)\n", + bio, fc->corrupt_bio_value, fc->corrupt_bio_byte, + (bio_data_dir(bio) == WRITE) ? 'w' : 'r', bio->bi_opf, + (unsigned long long)bio->bi_iter.bi_sector, bio->bi_iter.bi_size); + break; + } + corrupt_bio_byte -= bio_iter_len(bio, iter); } } -- 2.20.1