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 X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 54582C433F5 for ; Thu, 9 Sep 2021 11:23:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2F21B61104 for ; Thu, 9 Sep 2021 11:23:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234993AbhIILYP (ORCPT ); Thu, 9 Sep 2021 07:24:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234902AbhIILYO (ORCPT ); Thu, 9 Sep 2021 07:24:14 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3ED3FC061575; Thu, 9 Sep 2021 04:23:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=M0gopQrsLr3UAE05SLf2KetoSMl+JUlvHkNklgk7J9I=; b=eKmuEo4gN8a1EQvUGgpk6G4bYV 88f9akYrx4vCinB+HrE5W4fV4xy5i0AZjkMIi4jKkgdOw1jLlLbHHRVOiDTaO/4nNS0K1HLejmpe5 0o5YZQtKGjDkNmcjr5dUaSb2Zmaeo9iUc58oBQEvnfo7jg4ElgxLUgr3ubxQLXr6EYRerwp0qz+3F 1EscQ3c8K7ZiaH+IKihiC/tfZCgXwy8y+PtUSKGxwi2e7V8UgQGIhGToNFsvjT9EHnAOOJEhH5LSz 8xRdQhq1nmn6JpTmQuf9R/LsczQVWETH5dW8lGkfcqPUa0dY7yMLhVllKxsr5hiiX1jo1EOyNT+w7 +VEvjvfQ==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mOI6o-009l4w-TK; Thu, 09 Sep 2021 11:20:53 +0000 Date: Thu, 9 Sep 2021 12:20:46 +0100 From: Christoph Hellwig To: Andreas Gruenbacher Cc: Linus Torvalds , Alexander Viro , Christoph Hellwig , "Darrick J. Wong" , Jan Kara , Matthew Wilcox , cluster-devel@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, ocfs2-devel@oss.oracle.com Subject: Re: [PATCH v7 15/19] iomap: Support partial direct I/O on user copy failures Message-ID: References: <20210827164926.1726765-1-agruenba@redhat.com> <20210827164926.1726765-16-agruenba@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210827164926.1726765-16-agruenba@redhat.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Aug 27, 2021 at 06:49:22PM +0200, Andreas Gruenbacher wrote: > In iomap_dio_rw, when iomap_apply returns an -EFAULT error and the > IOMAP_DIO_PARTIAL flag is set, complete the request synchronously and > return a partial result. This allows the caller to deal with the page > fault and retry the remainder of the request. > > Signed-off-by: Andreas Gruenbacher > --- > fs/iomap/direct-io.c | 6 ++++++ > include/linux/iomap.h | 7 +++++++ > 2 files changed, 13 insertions(+) > > diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c > index 8054f5d6c273..ba88fe51b77a 100644 > --- a/fs/iomap/direct-io.c > +++ b/fs/iomap/direct-io.c > @@ -561,6 +561,12 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, > ret = iomap_apply(inode, pos, count, iomap_flags, ops, dio, > iomap_dio_actor); > if (ret <= 0) { > + if (ret == -EFAULT && dio->size && > + (dio_flags & IOMAP_DIO_PARTIAL)) { > + wait_for_completion = true; > + ret = 0; Do we need a NOWAIT check here to skip the wait_for_completion for that case?