From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on gnuweeb.org X-Spam-Level: X-Spam-Status: No, score=0.9 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_PASS,SPF_SOFTFAIL,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.6 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D5A1C433EF for ; Thu, 2 Jun 2022 12:38:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235013AbiFBMii (ORCPT ); Thu, 2 Jun 2022 08:38:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233380AbiFBMih (ORCPT ); Thu, 2 Jun 2022 08:38:37 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E25131D0FC; Thu, 2 Jun 2022 05:38:33 -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=s5OuhuXYOeyE5UF5dmXoLvghk44rQZnLPb2h1/XcCPg=; b=CLdDZpnXhsBm2c9XM9B5FToU/M LyNk4DIYVj1phFej49cZkTUIX9N0diwt44Ff6V3AAWidHxpiqQOieGX/Yo6Zz60us5Gm931KmiSnQ xkOiHmp8M23pbLA5AjuvsK0k5SeUjKvY66a1zkj2BtuV9XT/3N6o97VijmXSCUw00txBRgKdzN2Zq fdQJuAkoUTA4KZXnhfn9pdiiN0SmNKPjY9p1rRLfyAMGRbHtU7otoJwe9lt9jMhs91gJRaD6RTF3T F16+aSgbAIAjhd9MEQ6hjBeC1a/wN2fwO3WvSegDJebimWMhSNwN9Pite5GoHG1gEEx8SxS0sTFAK 88Qw4STA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nwk5q-0078sD-1n; Thu, 02 Jun 2022 12:38:26 +0000 Date: Thu, 2 Jun 2022 13:38:26 +0100 From: Matthew Wilcox To: Stefan Roesch Cc: io-uring@vger.kernel.org, kernel-team@fb.com, linux-mm@kvack.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, david@fromorbit.com, jack@suse.cz, hch@infradead.org, axboe@kernel.dk Subject: Re: [PATCH v7 06/15] iomap: Return error code from iomap_write_iter() Message-ID: References: <20220601210141.3773402-1-shr@fb.com> <20220601210141.3773402-7-shr@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220601210141.3773402-7-shr@fb.com> Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Wed, Jun 01, 2022 at 02:01:32PM -0700, Stefan Roesch wrote: > Change the signature of iomap_write_iter() to return an error code. In > case we cannot allocate a page in iomap_write_begin(), we will not retry > the memory alloction in iomap_write_begin(). loff_t can already represent an error code. And it's already used like that. > @@ -829,7 +830,8 @@ static loff_t iomap_write_iter(struct iomap_iter *iter, struct iov_iter *i) > length -= status; > } while (iov_iter_count(i) && length); > > - return written ? written : status; > + *processed = written ? written : error; > + return error; I think the change you really want is: if (status == -EAGAIN) return -EAGAIN; if (written) return written; return status; > @@ -843,12 +845,15 @@ iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *i, > .flags = IOMAP_WRITE, > }; > int ret; > + int error = 0; > > if (iocb->ki_flags & IOCB_NOWAIT) > iter.flags |= IOMAP_NOWAIT; > > - while ((ret = iomap_iter(&iter, ops)) > 0) > - iter.processed = iomap_write_iter(&iter, i); > + while ((ret = iomap_iter(&iter, ops)) > 0) { > + if (error != -EAGAIN) > + error = iomap_write_iter(&iter, i, &iter.processed); > + } You don't need to change any of this. Look at how iomap_iter_advance() works.