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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 67E18C432C3 for ; Fri, 22 Nov 2019 06:02:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3ABF02068F for ; Fri, 22 Nov 2019 06:02:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574402529; bh=zZruYX87mevRMIX7WAXQ0HW9SLzcEcLIwjQKbU+516E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sx6KarSCcLnE/c3x6hpm1j/jano8xrBXuhazaGSZq+NIPOUqGMMuGyVKC+PZ0y2dJ sWqdMC+1gY3DehxE4symig4aECnRd+6HZgDDuLNczIs/9vJ+OddoT6mtT8cjbrkUJl DuM81tSDMq1sZCiG/1uRvMrVZ2KpDu0J4WFMozzA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729596AbfKVGCI (ORCPT ); Fri, 22 Nov 2019 01:02:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:40536 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729514AbfKVGCF (ORCPT ); Fri, 22 Nov 2019 01:02:05 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8EA3A2071F; Fri, 22 Nov 2019 06:02:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574402524; bh=zZruYX87mevRMIX7WAXQ0HW9SLzcEcLIwjQKbU+516E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=B5qWF4mwCJV/AXfEeBhRO212TbRysJdNQQ9X1poqrEckTfQ/cskt4VHN+MKY6SVGS WlkBNXD2XuppZGaf5XJjvKLTKeQ41jwKVyZcrdb7eI6jCFBLRe5HOF+SAjZKXIrIat eKO8RAndMJ90707fQUmscA0YiEKYOzVK853/K2XY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sweet Tea , John Dorminy , Mike Snitzer , Sasha Levin , dm-devel@redhat.com Subject: [PATCH AUTOSEL 4.9 32/91] dm flakey: Properly corrupt multi-page bios. Date: Fri, 22 Nov 2019 01:00:30 -0500 Message-Id: <20191122060129.4239-31-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191122060129.4239-1-sashal@kernel.org> References: <20191122060129.4239-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 3643cba713518..742c1fa870dae 100644 --- a/drivers/md/dm-flakey.c +++ b/drivers/md/dm-flakey.c @@ -258,20 +258,31 @@ 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