From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752329AbaKUUjn (ORCPT ); Fri, 21 Nov 2014 15:39:43 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:21381 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751826AbaKUUjm (ORCPT ); Fri, 21 Nov 2014 15:39:42 -0500 Date: Fri, 21 Nov 2014 12:39:38 -0800 From: "Darrick J. Wong" To: Jens Axboe , "Martin K. Petersen" Cc: linux-kernel@vger.kernel.org Subject: [PATCH] block: bio_integrity_process uses wrong bio_vec iterator Message-ID: <20141121203938.GD10047@birch.djwong.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org bio integrity handling is broken on a system with LVM layered atop a DIF/DIX SCSI drive because device mapper clones the bio, modifies the clone, and sends the clone to the lower layers for processing. However, the clone bio has bi_vcnt == 0, which means that when the sd driver calls bio_integrity_process to attach DIX data, the for_each_segment_all() call (which uses bi_vcnt) returns immediately and random garbage is sent to the disk on a disk write. The disk of course returns error when it's fed garbage for checksums. Therefore, teach bio_integrity_process() to use bio_for_each_segment() to iterate the bio_vecs, since the per-bio iterator tracks which bio_vecs are associated with that particular bio. The integrity handling code is effectively part of the "driver" (it's not the bio owner), so it must use the correct iterator function. Signed-off-by: Darrick J. Wong --- block/bio-integrity.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/block/bio-integrity.c b/block/bio-integrity.c index 0984232..e1a320d 100644 --- a/block/bio-integrity.c +++ b/block/bio-integrity.c @@ -216,7 +216,8 @@ static int bio_integrity_process(struct bio *bio, { struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev); struct blk_integrity_iter iter; - struct bio_vec *bv; + struct bvec_iter bviter; + struct bio_vec bv; struct bio_integrity_payload *bip = bio_integrity(bio); unsigned int i, ret = 0; void *prot_buf = page_address(bip->bip_vec->bv_page) + @@ -227,11 +228,11 @@ static int bio_integrity_process(struct bio *bio, iter.seed = bip_get_seed(bip); iter.prot_buf = prot_buf; - bio_for_each_segment_all(bv, bio, i) { - void *kaddr = kmap_atomic(bv->bv_page); + bio_for_each_segment(bv, bio, bviter) { + void *kaddr = kmap_atomic(bv.bv_page); - iter.data_buf = kaddr + bv->bv_offset; - iter.data_size = bv->bv_len; + iter.data_buf = kaddr + bv.bv_offset; + iter.data_size = bv.bv_len; ret = proc_fn(&iter); if (ret) {