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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 CB45CC433DB for ; Wed, 3 Mar 2021 01:33:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C597564E21 for ; Wed, 3 Mar 2021 01:33:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C597564E21 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2E0228D0114; Tue, 2 Mar 2021 20:33:28 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 2900F8D00FA; Tue, 2 Mar 2021 20:33:28 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1808D8D0114; Tue, 2 Mar 2021 20:33:28 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0082.hostedemail.com [216.40.44.82]) by kanga.kvack.org (Postfix) with ESMTP id ED04A8D00FA for ; Tue, 2 Mar 2021 20:33:27 -0500 (EST) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id AB0C083EB for ; Wed, 3 Mar 2021 01:33:27 +0000 (UTC) X-FDA: 77876840454.13.77D85D2 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf13.hostedemail.com (Postfix) with ESMTP id 7AA25E0011E3 for ; Wed, 3 Mar 2021 01:33:25 +0000 (UTC) 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=UUCunpPK/kEanZj5qySdAgYlSOPrCb0CzB9Vx5ufnXY=; b=KwIWmwUhK2ceCpxvoFWtLsuxLu mayXYnhwOt/Q8WQI7S8tL6z/cRUtwyWdrmQwOuOEwQwUcU529uChVXxmpUhZS7dMjBY0c3STSR7qB A6ujRtTGvvMY9Rc0BA80wyoXja0TCviYQ2CPyEm0Ry6tVwDIV/aAzoXQzUSpg5jt9YSApJWLPGl7T FXE+bedrynxDeAAn519S72xD/rISeTaIONR69bzLVoRsDdkS392N7LhKqXGMw6RJspOJzYTTfVphy 8qCe2HYHyX8dCE6v9PHubLeKZGxcbNdsu9MI7xi91xqGQA1tlGm6MOO7tZn+p7ZBYDGCeeaChMEtr V7UsGGhg==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lHGO1-000sSZ-KF; Wed, 03 Mar 2021 01:33:14 +0000 Date: Wed, 3 Mar 2021 01:33:13 +0000 From: Matthew Wilcox To: Andrew Morton Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Kent Overstreet , Christoph Hellwig Subject: Re: [PATCH] mm/filemap: Use filemap_read_page in filemap_fault Message-ID: <20210303013313.GZ2723601@casper.infradead.org> References: <20210226140011.2883498-1-willy@infradead.org> <20210302173039.4625f403846abd20413f6dad@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210302173039.4625f403846abd20413f6dad@linux-foundation.org> X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 7AA25E0011E3 X-Stat-Signature: 8o1n4tsxpmn5g97iriewn3suztqztmyu Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf13; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614735205-874769 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Mar 02, 2021 at 05:30:39PM -0800, Andrew Morton wrote: > On Fri, 26 Feb 2021 14:00:11 +0000 "Matthew Wilcox (Oracle)" wrote: > > > After splitting generic_file_buffered_read() into smaller parts, it > > turns out we can reuse one of the parts in filemap_fault(). This fixes > > an oversight -- waiting for the I/O to complete is now interruptible > > by a fatal signal. And it saves us a few bytes of text in an unlikely > > path. > > We also handle AOP_TRUNCATED_PAGE which the present code fails to do. > Should this be in the changelog? No, the present code does handle AOP_TRUNCATED_PAGE. It's perhaps not the clearest in the diff, but it's there. Here's git show -U5: - ClearPageError(page); fpin = maybe_unlock_mmap_for_io(vmf, fpin); - error = mapping->a_ops->readpage(file, page); - if (!error) { - wait_on_page_locked(page); - if (!PageUptodate(page)) - error = -EIO; - } + error = filemap_read_page(file, mapping, page); if (fpin) goto out_retry; put_page(page); if (!error || error == AOP_TRUNCATED_PAGE) goto retry_find; - shrink_readahead_size_eio(ra); return VM_FAULT_SIGBUS;