Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751520AbdFZSI1 (ORCPT ); Mon, 26 Jun 2017 14:08:27 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:39181 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751308AbdFZSIU (ORCPT ); Mon, 26 Jun 2017 14:08:20 -0400 Date: Mon, 26 Jun 2017 11:04:01 -0700 From: Liu Bo To: Ming Lei Cc: Jens Axboe , Christoph Hellwig , Huang Ying , Andrew Morton , Alexander Viro , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Chris Mason , Josef Bacik , David Sterba , linux-btrfs@vger.kernel.org Subject: Re: [PATCH v2 14/51] btrfs: avoid to access bvec table directly for a cloned bio Message-ID: <20170626180401.GB31661@lim.localdomain> Reply-To: bo.li.liu@oracle.com References: <20170626121034.3051-1-ming.lei@redhat.com> <20170626121034.3051-15-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170626121034.3051-15-ming.lei@redhat.com> User-Agent: Mutt/1.8.3 (2017-05-23) X-Source-IP: aserv0021.oracle.com [141.146.126.233] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1509 Lines: 48 On Mon, Jun 26, 2017 at 08:09:57PM +0800, Ming Lei wrote: > Commit 17347cec15f919901c90(Btrfs: change how we iterate bios in endio) > mentioned that for dio the submitted bio may be fast cloned, we > can't access the bvec table directly for a cloned bio, so use > bio_get_first_bvec() to retrieve the 1st bvec. > Looks good to me. Reviewed-by: Liu Bo -liubo > Cc: Chris Mason > Cc: Josef Bacik > Cc: David Sterba > Cc: linux-btrfs@vger.kernel.org > Cc: Liu Bo > Signed-off-by: Ming Lei > --- > fs/btrfs/inode.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 06dea7c89bbd..4ab02b34f029 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -7993,6 +7993,7 @@ static int dio_read_error(struct inode *inode, struct bio *failed_bio, > int read_mode = 0; > int segs; > int ret; > + struct bio_vec bvec; > > BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE); > > @@ -8008,8 +8009,9 @@ static int dio_read_error(struct inode *inode, struct bio *failed_bio, > } > > segs = bio_segments(failed_bio); > + bio_get_first_bvec(failed_bio, &bvec); > if (segs > 1 || > - (failed_bio->bi_io_vec->bv_len > btrfs_inode_sectorsize(inode))) > + (bvec.bv_len > btrfs_inode_sectorsize(inode))) > read_mode |= REQ_FAILFAST_DEV; > > isector = start - btrfs_io_bio(failed_bio)->logical; > -- > 2.9.4 >