Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754315AbeAAOmF (ORCPT + 1 other); Mon, 1 Jan 2018 09:42:05 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:45644 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754285AbeAAOl7 (ORCPT ); Mon, 1 Jan 2018 09:41:59 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, NeilBrown , Michele Ballabio , Ming Lei , Jens Axboe Subject: [PATCH 4.14 057/146] block: dont let passthrough IO go into .make_request_fn() Date: Mon, 1 Jan 2018 15:37:28 +0100 Message-Id: <20180101140132.403591796@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180101140123.743014891@linuxfoundation.org> References: <20180101140123.743014891@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ming Lei commit 14cb0dc6479dc5ebc63b3a459a5d89a2f1b39fed upstream. Commit a8821f3f3("block: Improvements to bounce-buffer handling") tries to make sure that the bio to .make_request_fn won't exceed BIO_MAX_PAGES, but ignores that passthrough I/O can use blk_queue_bounce() too. Especially, passthrough IO may not be sector-aligned, and the check of 'sectors < bio_sectors(*bio_orig)' inside __blk_queue_bounce() may become true even though the max bvec number doesn't exceed BIO_MAX_PAGES, then cause the bio splitted, and the original passthrough bio is submited to generic_make_request(). This patch fixes this issue by checking if the bio is passthrough IO, and use bio_kmalloc() to allocate the cloned passthrough bio. Cc: NeilBrown Fixes: a8821f3f3("block: Improvements to bounce-buffer handling") Tested-by: Michele Ballabio Signed-off-by: Ming Lei Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- block/bounce.c | 6 ++++-- include/linux/blkdev.h | 21 +++++++++++++++++++-- 2 files changed, 23 insertions(+), 4 deletions(-) --- a/block/bounce.c +++ b/block/bounce.c @@ -200,6 +200,7 @@ static void __blk_queue_bounce(struct re unsigned i = 0; bool bounce = false; int sectors = 0; + bool passthrough = bio_is_passthrough(*bio_orig); bio_for_each_segment(from, *bio_orig, iter) { if (i++ < BIO_MAX_PAGES) @@ -210,13 +211,14 @@ static void __blk_queue_bounce(struct re if (!bounce) return; - if (sectors < bio_sectors(*bio_orig)) { + if (!passthrough && sectors < bio_sectors(*bio_orig)) { bio = bio_split(*bio_orig, sectors, GFP_NOIO, bounce_bio_split); bio_chain(bio, *bio_orig); generic_make_request(*bio_orig); *bio_orig = bio; } - bio = bio_clone_bioset(*bio_orig, GFP_NOIO, bounce_bio_set); + bio = bio_clone_bioset(*bio_orig, GFP_NOIO, passthrough ? NULL : + bounce_bio_set); bio_for_each_segment_all(to, bio, i) { struct page *page = to->bv_page; --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -241,14 +241,24 @@ struct request { struct request *next_rq; }; +static inline bool blk_op_is_scsi(unsigned int op) +{ + return op == REQ_OP_SCSI_IN || op == REQ_OP_SCSI_OUT; +} + +static inline bool blk_op_is_private(unsigned int op) +{ + return op == REQ_OP_DRV_IN || op == REQ_OP_DRV_OUT; +} + static inline bool blk_rq_is_scsi(struct request *rq) { - return req_op(rq) == REQ_OP_SCSI_IN || req_op(rq) == REQ_OP_SCSI_OUT; + return blk_op_is_scsi(req_op(rq)); } static inline bool blk_rq_is_private(struct request *rq) { - return req_op(rq) == REQ_OP_DRV_IN || req_op(rq) == REQ_OP_DRV_OUT; + return blk_op_is_private(req_op(rq)); } static inline bool blk_rq_is_passthrough(struct request *rq) @@ -256,6 +266,13 @@ static inline bool blk_rq_is_passthrough return blk_rq_is_scsi(rq) || blk_rq_is_private(rq); } +static inline bool bio_is_passthrough(struct bio *bio) +{ + unsigned op = bio_op(bio); + + return blk_op_is_scsi(op) || blk_op_is_private(op); +} + static inline unsigned short req_get_ioprio(struct request *req) { return req->ioprio;