From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:46952 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387859AbfFJIh6 (ORCPT ); Mon, 10 Jun 2019 04:37:58 -0400 Date: Mon, 10 Jun 2019 16:37:39 +0800 From: Ming Lei Subject: Re: [PATCH V2 0/2] block: fix page leak by merging to same page Message-ID: <20190610083738.GB15024@ming.t460p> References: <20190610041819.11575-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190610041819.11575-1-ming.lei@redhat.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Jens Axboe Cc: linux-block@vger.kernel.org, David Gibson , "Darrick J. Wong" , linux-xfs@vger.kernel.org, Alexander Viro , Christoph Hellwig On Mon, Jun 10, 2019 at 12:18:17PM +0800, Ming Lei wrote: > Hi, > > 'pages' retrived by __bio_iov_iter_get_pages() may point to same page, > and finally they can be merged to the same page in bio_add_page(), then > page leak can be caused because bio_release_pages() only drops the page > ref once. > > Fixes this issue by dropping the extra page ref. > > V2: > - V1 breaks multi-page merge, and fix it and only put the page ref > if the added page is really the 'same page' > > > Ming Lei (2): > block: introduce 'enum bvec_merge_flags' for __bio_try_merge_page > block: fix page leak in case of merging to same page > > block/bio.c | 32 ++++++++++++++++++++++---------- > fs/iomap.c | 3 ++- > fs/xfs/xfs_aops.c | 3 ++- > include/linux/bio.h | 9 ++++++++- > 4 files changed, 34 insertions(+), 13 deletions(-) > > Cc: David Gibson > Cc: "Darrick J. Wong" > Cc: linux-xfs@vger.kernel.org > Cc: Alexander Viro > Cc: Christoph Hellwig > -- > 2.20.1 > Please ignore V2, I will improve it a bit and post out V3. Thanks Ming