From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:56991 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726070AbfFJESc (ORCPT ); Mon, 10 Jun 2019 00:18:32 -0400 From: Ming Lei Subject: [PATCH V2 0/2] block: fix page leak by merging to same page Date: Mon, 10 Jun 2019 12:18:17 +0800 Message-Id: <20190610041819.11575-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Jens Axboe Cc: linux-block@vger.kernel.org, Ming Lei , David Gibson , "Darrick J. Wong" , linux-xfs@vger.kernel.org, Alexander Viro , Christoph Hellwig 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