From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754289AbaE1PK1 (ORCPT ); Wed, 28 May 2014 11:10:27 -0400 Received: from mail-wi0-f178.google.com ([209.85.212.178]:58458 "EHLO mail-wi0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932240AbaE1PKS (ORCPT ); Wed, 28 May 2014 11:10:18 -0400 From: Dongsu Park To: linux-kernel@vger.kernel.org Cc: Dongsu Park , Jens Axboe , Jet Chen , Maurizio Lombardi Subject: [PATCH] bio: decrease bi_iter.bi_size by len in the fail path Date: Wed, 28 May 2014 17:09:38 +0200 Message-Id: <1401289778-9840-1-git-send-email-dongsu.park@profitbricks.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <20140527112459.GF2205@dhcp-27-189.brq.redhat.com> References: <20140527112459.GF2205@dhcp-27-189.brq.redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dongsu Park Commit 3979ef4dcf3d1de55a560a3a4016c30a835df44d ("bio-modify- __bio_add_page-to-accept-pages-that-dont-start-a-new-segment-v3") introduced a regression as reported by Jet Chen. That results in a kernel BUG at drivers/block/virtio_blk.c:166. To fix that, bi_iter.bi_size must be decreased by len, before recounting the number of physical segments. Tested on with kernel 3.15.0-rc7-next-20140527 on qemu guest, by running xfstests/ext4/271. Cc: Jens Axboe Cc: Jet Chen Cc: Maurizio Lombardi Signed-off-by: Dongsu Park --- block/bio.c | 1 + 1 file changed, 1 insertion(+) diff --git a/block/bio.c b/block/bio.c index 0443694ccbb4..67d7cba1e5fd 100644 --- a/block/bio.c +++ b/block/bio.c @@ -810,6 +810,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page bvec->bv_len = 0; bvec->bv_offset = 0; bio->bi_vcnt--; + bio->bi_iter.bi_size -= len; blk_recount_segments(q, bio); return 0; } -- 1.9.1