From patchwork Tue Apr 26 17:43:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Roesch X-Patchwork-Id: 12827631 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 A590DC4332F for ; Tue, 26 Apr 2022 17:44:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352075AbiDZRrM (ORCPT ); Tue, 26 Apr 2022 13:47:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41110 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349342AbiDZRrH (ORCPT ); Tue, 26 Apr 2022 13:47:07 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 280411816FA for ; Tue, 26 Apr 2022 10:43:56 -0700 (PDT) Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 23QGQeAQ017050 for ; Tue, 26 Apr 2022 10:43:56 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=sVaCe7n8PQWmshIX6gLNdmwvF5amYzdsvPLOsBIpxFY=; b=de9wCTDnCaO3DYx4UvPg8EdhK9JTmC0DM6dcTNRpEa5JRxkKBZRTDMTMFAy9zZKKtEmE i3AGjhSaKCN5V4vsFI3dA8evAEFWJ2GCFOnGr94i5z2ylQ1SuVUcZ3NiWghG0pOOE3FM IYNIb+/fUaAQ9SOLNftdiNW4U3IWQUfnDPk= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3fp6a8d4kj-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 26 Apr 2022 10:43:55 -0700 Received: from twshared29473.14.frc2.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::f) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 26 Apr 2022 10:43:54 -0700 Received: by devvm225.atn0.facebook.com (Postfix, from userid 425415) id 8EE03E2D485D; Tue, 26 Apr 2022 10:43:40 -0700 (PDT) From: Stefan Roesch To: , , , , CC: , Subject: [RFC PATCH v1 05/18] iomap: add async buffered write support Date: Tue, 26 Apr 2022 10:43:22 -0700 Message-ID: <20220426174335.4004987-6-shr@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220426174335.4004987-1-shr@fb.com> References: <20220426174335.4004987-1-shr@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: YLUuf581Xn2w0scGuvC8FruHIJLNZpyo X-Proofpoint-ORIG-GUID: YLUuf581Xn2w0scGuvC8FruHIJLNZpyo X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.858,Hydra:6.0.486,FMLib:17.11.64.514 definitions=2022-04-26_05,2022-04-26_02,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This adds async buffered write support to iomap. The support is focused on the changes necessary to support XFS with iomap. Support for other filesystems might require additional changes. Signed-off-by: Stefan Roesch --- fs/iomap/buffered-io.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 1ffdc7078e7d..5c53a5715c85 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -580,13 +580,20 @@ static int __iomap_write_begin(const struct iomap_iter *iter, loff_t pos, size_t from = offset_in_folio(folio, pos), to = from + len; size_t poff, plen; gfp_t gfp = GFP_NOFS | __GFP_NOFAIL; + bool no_wait = (iter->flags & IOMAP_NOWAIT); + + if (no_wait) + gfp = GFP_NOIO | GFP_ATOMIC; if (folio_test_uptodate(folio)) return 0; folio_clear_error(folio); - if (!iop && nr_blocks > 1) + if (!iop && nr_blocks > 1) { iop = iomap_page_create_gfp(iter->inode, folio, nr_blocks, gfp); + if (no_wait && !iop) + return -EAGAIN; + } do { iomap_adjust_read_range(iter->inode, folio, &block_start, @@ -603,6 +610,8 @@ static int __iomap_write_begin(const struct iomap_iter *iter, loff_t pos, if (WARN_ON_ONCE(iter->flags & IOMAP_UNSHARE)) return -EIO; folio_zero_segments(folio, poff, from, to, poff + plen); + } else if (no_wait) { + return -EAGAIN; } else { int status = iomap_read_folio_sync(block_start, folio, poff, plen, srcmap); @@ -633,6 +642,9 @@ static int iomap_write_begin(const struct iomap_iter *iter, loff_t pos, unsigned fgp = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE | FGP_NOFS; int status = 0; + if (iter->flags & IOMAP_NOWAIT) + fgp |= FGP_NOWAIT | FGP_ATOMIC; + BUG_ON(pos + len > iter->iomap.offset + iter->iomap.length); if (srcmap != &iter->iomap) BUG_ON(pos + len > srcmap->offset + srcmap->length); @@ -790,6 +802,10 @@ static loff_t iomap_write_iter(struct iomap_iter *iter, struct iov_iter *i) * Otherwise there's a nasty deadlock on copying from the * same page as we're writing to, without it being marked * up-to-date. + * + * For async buffered writes the assumption is that the user + * page has already been faulted in. This can be optimized by + * faulting the user page in the prepare phase of io-uring. */ if (unlikely(fault_in_iov_iter_readable(i, bytes) == bytes)) { status = -EFAULT; @@ -845,6 +861,9 @@ iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *i, }; int ret; + if (iocb->ki_flags & IOCB_NOWAIT) + iter.flags |= IOMAP_NOWAIT; + while ((ret = iomap_iter(&iter, ops)) > 0) iter.processed = iomap_write_iter(&iter, i); if (iter.pos == iocb->ki_pos)