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 8E36DC433EF for ; Wed, 24 Nov 2021 06:18:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233387AbhKXGV2 (ORCPT ); Wed, 24 Nov 2021 01:21:28 -0500 Received: from mout.gmx.net ([212.227.15.19]:43327 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232689AbhKXGV2 (ORCPT ); Wed, 24 Nov 2021 01:21:28 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1637734686; bh=TUZFvBsMw1AsvORHoT7iSE7LY1SgcnSYgHu/zaSlMsw=; h=X-UI-Sender-Class:Date:Subject:To:Cc:References:From:In-Reply-To; b=AqAAuKWthH1u32A++CSLY6ojp8tMC3jMydfHxoJwFoYWD5isB+axsOx3YbqMIOSsN +9tzlVo0LH1swZWFDjb5vvhdNX41m1J4ADZ2aoUsW2U/h2fcWZqdi43vEVSis67uqR XwepjWjgSuYlkk79bvJCMkmK1EkEnaTfRSWH67ac= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.net (mrgmx005 [212.227.17.184]) with ESMTPSA (Nemesis) id 1MWRRZ-1n9mX02bb1-00XrAu; Wed, 24 Nov 2021 07:18:06 +0100 Message-ID: Date: Wed, 24 Nov 2021 14:18:00 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.3.1 Subject: Re: Any bio_clone_slow() implementation which doesn't share bi_io_vec? Content-Language: en-US To: "hch@infradead.org" Cc: Johannes Thumshirn , Linux FS Devel , "dm-devel@redhat.com" , "linux-btrfs@vger.kernel.org" References: <5d8351f1-1b09-bff0-02f2-a417c1669607@gmx.com> <79d38fc2-cd2f-2980-2c4e-408078ce6079@gmx.com> <133792e9-b89b-bc82-04fe-41202c3453a5@gmx.com> From: Qu Wenruo In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:ZxeW4fJ7S5g/EUK+d5QXEFC182bf1PlurcjtsWZRReag8gJgaTQ WTvu1uZm/uhZXTkXL/puyXAqIJpf2YyYP4o5qQrxRjeVeK8i6LT1VF449mq/tQBJ0ThUiKH fEtg2oRg51Tvg08PS6L4Gm9uRvu7K+Zt1DqmlnlcQia5Y+geaQSAMD/jvUsghoxaPmox1tF bzEg5YJtOhpbxWsPfcVlA== X-UI-Out-Filterresults: notjunk:1;V03:K0:bAzBGslp/jM=:kkpMcgLlLndXSNdeIchiCx pIR6pFjsyX1M4YrTNq63w5Mgv1GOUf7bBllfDTYhM5jx8FIIVLoHJuPYsFSa6FAbKgTNN0EVt QMVpUH8ppvcGBtgcu+8pXfhz/n1XOCMJezr8M8ChRSTnA4O+QgL4YTnpevVeEWWeYt6NegRIV NrtfTg21n5m/NIj+SzRU/BfTWAJ839qVLzDfwxGPXM392U52+Y2G8OM4I0SUA2m+3NPQVpaUt UGpDL1edhXtaAYJLAKuuBQ9JfRyyJ0byR0Sy/eoxgcj38ZRuQjnnXOyBfAy5bhrzhAm6ok4Ul GAot0c3NLL7dWSYjeN6G6WhRFOXMVf4GPkkEiEdGl2kvk8MuWaA25TeFnEaK4qN5xYzuozCWo d3z7GNufCJKUSDUlzwFIQWjj3yv1ys6yC+bpOdR6E4KZg0QpEyjWYNecy1ufAT6Au4yOvkDdi oS125Wl2PwxnbTpFUm6MfeTxK2hatGZ0UCppAHKcT3BTVldfanL2ubbX5CcNZ3pYNuI97t4Ke 8h62Iix1Zs+9/qrDYW05O4PCDFecwiNgFRDRWT6N3PelYJLQER+iIc6WgwEfUbuuM3MN9lRSz k1BqejtqFDhQLlAUemXXkC8vPmNU8k951f5jH2CAxz1YUfTY7W+nFGZEojyrb/wg+mKNNG2hC dZULNm5MjwW+bCscpAbAmHJUzAP3I/XZ0EVxgAWmP4oWa71ikH28sxbOInQzuQdDGDzu69csc YqYKtO5T5y7RqVb1++uJZEU3tcGKy9/UnzrMyqYM8G0I+NLkEi+Sy0WwoGg7jE3525nhVNV+F OA06h5mYi9b4bWn/RgBmli65bu9PpsZrYgG+kbVB+sOzitqiOErZkCjnEJ5SKXI+HIqcE9a7R c7W9fvxSPbluB05bJSww+ZGwhccrB46V0cI1Xi1VFkzYK6bebX2G0rCotMyW73TNZ6TrvNCDC bOYldivwFoAtwutXQl1bDdnUtbkiZgi42DeeraTGxlJ3cBs2LowrY06UK/b5IKD2jyc4S8WW6 3LuJyN6y0abbH/o7YdqclJE3gA/o39lKL5ywLpABTITwzXYPXns7Z0lkG2o8a/kn0lNuxdj7s oHOM4f1JMXULaU= Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 2021/11/24 14:09, hch@infradead.org wrote: > On Wed, Nov 24, 2021 at 07:07:18AM +0800, Qu Wenruo wrote: >> In that case, the missing piece seems to be a way to convert a splitted >> plain bio into a REQ_OP_ZONE_APPEND bio. >> >> Can this be done without slow bvec copying? > > Yes. I have a WIP stacking driver that converts writes to zone appends > and it does just that: > > sector_t orig_sector =3D bio->bi_iter.bi_sector; > unsigned int bio_flags =3D bio->bi_opf & ~REQ_OP_MASK; > > ... > > clone =3D bio_clone_fast(bio, GFP_NOIO, &bdev->write_bio_set); > > ... > > clone->bi_opf =3D REQ_OP_ZONE_APPEND | REQ_NOMERGE | bio_flags; Just so simple? Then that's super awesome. But I'm a little concerned about the bio_add_hw_page() call in bio_add_zoned_append(). It's not exactly the same as bio_add_page(). Does it mean as long as our splitted bio doesn't exceed zone limit, we can do the convert without any further problem? Thanks, Qu > bio_set_dev(clone, dev->lower_bdev); > clone->bi_iter.bi_sector =3D zone_sector; > trace_block_bio_remap(clone, disk_devt(disk), orig_sector); > >> >> Thanks, >> Qu > ---end quoted text--- >