From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94234ECAAD8 for ; Tue, 20 Sep 2022 12:02:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229839AbiITMCd (ORCPT ); Tue, 20 Sep 2022 08:02:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229518AbiITMCc (ORCPT ); Tue, 20 Sep 2022 08:02:32 -0400 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D624A614E; Tue, 20 Sep 2022 05:02:30 -0700 (PDT) Received: by verein.lst.de (Postfix, from userid 2407) id 213FE68AA6; Tue, 20 Sep 2022 14:02:27 +0200 (CEST) Date: Tue, 20 Sep 2022 14:02:26 +0200 From: Christoph Hellwig To: Kanchan Joshi Cc: axboe@kernel.dk, hch@lst.de, kbusch@kernel.org, asml.silence@gmail.com, io-uring@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, gost.dev@samsung.com Subject: Re: [PATCH for-next v7 3/5] nvme: refactor nvme_alloc_user_request Message-ID: <20220920120226.GB2809@lst.de> References: <20220909102136.3020-1-joshi.k@samsung.com> <20220909102136.3020-4-joshi.k@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220909102136.3020-4-joshi.k@samsung.com> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Fri, Sep 09, 2022 at 03:51:34PM +0530, Kanchan Joshi wrote: > Separate this out to two functions with reduced number of arguments. > _ > Signed-off-by: Kanchan Joshi > --- > drivers/nvme/host/ioctl.c | 116 ++++++++++++++++++++++---------------- > 1 file changed, 66 insertions(+), 50 deletions(-) > > diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c > index 548aca8b5b9f..cb2fa4db50dd 100644 > --- a/drivers/nvme/host/ioctl.c > +++ b/drivers/nvme/host/ioctl.c > @@ -65,18 +65,10 @@ static int nvme_finish_user_metadata(struct request *req, void __user *ubuf, > } > > static struct request *nvme_alloc_user_request(struct request_queue *q, > + struct nvme_command *cmd, unsigned timeout, > blk_opf_t rq_flags, blk_mq_req_flags_t blk_flags) I think we can also drop the timeout flag here, which seems like it can be handled cleaner in the callers. to set it can just do that. > +static int nvme_map_user_request(struct request *req, void __user *ubuffer, > + unsigned bufflen, void __user *meta_buffer, unsigned meta_len, > + u32 meta_seed, void **metap, bool vec) > +{ > + struct request_queue *q = req->q; > + struct nvme_ns *ns = q->queuedata; > + struct block_device *bdev = ns ? ns->disk->part0 : NULL; > + struct bio *bio = NULL; > + void *meta = NULL; > + int ret; > + > + if (!ubuffer || !bufflen) > + return 0; I'd leave these in the callers and not call the helper if there is no data to transfer. > + > + if (!vec) > + ret = blk_rq_map_user(q, req, NULL, ubuffer, bufflen, > + GFP_KERNEL); > + else { > + struct iovec fast_iov[UIO_FASTIOV]; > + struct iovec *iov = fast_iov; > + struct iov_iter iter; > + > + ret = import_iovec(rq_data_dir(req), ubuffer, bufflen, > + UIO_FASTIOV, &iov, &iter); > + if (ret < 0) > goto out; > + ret = blk_rq_map_user_iov(q, req, NULL, &iter, GFP_KERNEL); > + kfree(iov); To me some of this almost screams like lifting the vectored vs not to the block layer into a separate helper. > + } > + bio = req->bio; > + if (ret) > + goto out_unmap; This seems incorrect, we don't need to unmap if blk_rq_map_user* failed. > + if (bdev) > + bio_set_dev(bio, bdev); I think we can actually drop this now - bi_bdev should only be used by the non-passthrough path these days. > + if (bdev && meta_buffer && meta_len) { > + meta = nvme_add_user_metadata(bio, meta_buffer, meta_len, > + meta_seed, req_op(req) == REQ_OP_DRV_OUT); > + if (IS_ERR(meta)) { > + ret = PTR_ERR(meta); > + goto out_unmap; > } > + req->cmd_flags |= REQ_INTEGRITY; > + *metap = meta; And if we pass the request to nvme_add_user_metadata, that can set REQ_INTEGRITY. And we don't need this second helper at all.