From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from verein.lst.de ([213.95.11.211]:49870 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727711AbeKPXti (ORCPT ); Fri, 16 Nov 2018 18:49:38 -0500 Date: Fri, 16 Nov 2018 14:37:10 +0100 From: Christoph Hellwig Subject: Re: [PATCH V10 07/19] btrfs: use bvec_last_segment to get bio's last page Message-ID: <20181116133710.GF3165@lst.de> References: <20181115085306.9910-1-ming.lei@redhat.com> <20181115085306.9910-8-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181115085306.9910-8-ming.lei@redhat.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Ming Lei Cc: Jens Axboe , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Dave Chinner , Kent Overstreet , Mike Snitzer , dm-devel@redhat.com, Alexander Viro , linux-fsdevel@vger.kernel.org, Shaohua Li , linux-raid@vger.kernel.org, linux-erofs@lists.ozlabs.org, David Sterba , linux-btrfs@vger.kernel.org, "Darrick J . Wong" , linux-xfs@vger.kernel.org, Gao Xiang , Christoph Hellwig , Theodore Ts'o , linux-ext4@vger.kernel.org, Coly Li , linux-bcache@vger.kernel.org, Boaz Harrosh , Bob Peterson , cluster-devel@redhat.com On Thu, Nov 15, 2018 at 04:52:54PM +0800, Ming Lei wrote: > index 2955a4ea2fa8..161e14b8b180 100644 > --- a/fs/btrfs/compression.c > +++ b/fs/btrfs/compression.c > @@ -400,8 +400,11 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start, > static u64 bio_end_offset(struct bio *bio) > { > struct bio_vec *last = bio_last_bvec_all(bio); > + struct bio_vec bv; > > - return page_offset(last->bv_page) + last->bv_len + last->bv_offset; > + bvec_last_segment(last, &bv); > + > + return page_offset(bv.bv_page) + bv.bv_len + bv.bv_offset; I don't think we need this. If last is a multi-page bvec bv_offset will already contain the correct offset from the first page.