From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161773Ab2CPHf4 (ORCPT ); Fri, 16 Mar 2012 03:35:56 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:35835 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161299Ab2CPHfY (ORCPT ); Fri, 16 Mar 2012 03:35:24 -0400 Message-Id: <20120316073512.401277270@fusionio.com> User-Agent: quilt/0.48-1 Date: Fri, 16 Mar 2012 15:32:14 +0800 From: Shaohua Li To: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org Cc: neilb@suse.de, axboe@kernel.dk, vgoyal@redhat.com, martin.petersen@oracle.com, Shaohua Li Subject: [patch v2 1/6] block: makes bio_split support bio without data References: <20120316073213.656519005@fusionio.com> Content-Disposition: inline; filename=bio_split-fix.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org discard bio hasn't data attached. We hit a BUG_ON with such bio. This makes bio_split works for such bio. Signed-off-by: Shaohua Li --- fs/bio.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) Index: linux/fs/bio.c =================================================================== --- linux.orig/fs/bio.c 2012-03-09 16:56:41.203790008 +0800 +++ linux/fs/bio.c 2012-03-12 10:10:40.696612399 +0800 @@ -1492,7 +1492,7 @@ struct bio_pair *bio_split(struct bio *b trace_block_split(bdev_get_queue(bi->bi_bdev), bi, bi->bi_sector + first_sectors); - BUG_ON(bi->bi_vcnt != 1); + BUG_ON(bi->bi_vcnt != 1 && bi->bi_vcnt != 0); BUG_ON(bi->bi_idx != 0); atomic_set(&bp->cnt, 3); bp->error = 0; @@ -1502,17 +1502,19 @@ struct bio_pair *bio_split(struct bio *b bp->bio2.bi_size -= first_sectors << 9; bp->bio1.bi_size = first_sectors << 9; - bp->bv1 = bi->bi_io_vec[0]; - bp->bv2 = bi->bi_io_vec[0]; - bp->bv2.bv_offset += first_sectors << 9; - bp->bv2.bv_len -= first_sectors << 9; - bp->bv1.bv_len = first_sectors << 9; + if (bi->bi_vcnt != 0) { + bp->bv1 = bi->bi_io_vec[0]; + bp->bv2 = bi->bi_io_vec[0]; + bp->bv2.bv_offset += first_sectors << 9; + bp->bv2.bv_len -= first_sectors << 9; + bp->bv1.bv_len = first_sectors << 9; - bp->bio1.bi_io_vec = &bp->bv1; - bp->bio2.bi_io_vec = &bp->bv2; + bp->bio1.bi_io_vec = &bp->bv1; + bp->bio2.bi_io_vec = &bp->bv2; - bp->bio1.bi_max_vecs = 1; - bp->bio2.bi_max_vecs = 1; + bp->bio1.bi_max_vecs = 1; + bp->bio2.bi_max_vecs = 1; + } bp->bio1.bi_end_io = bio_pair_end_1; bp->bio2.bi_end_io = bio_pair_end_2;