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 59293CD37A7 for ; Fri, 15 Sep 2023 19:46:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235142AbjIOTpn (ORCPT ); Fri, 15 Sep 2023 15:45:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237093AbjIOTp2 (ORCPT ); Fri, 15 Sep 2023 15:45:28 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D943C8E; Fri, 15 Sep 2023 12:45:22 -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=162ByQtUEtKATklSugznQjq/HmritqoY8YxWx3GTMHQ=; b=of/bPBGMK23VCoRz50gjg0FFj9 D0Xt0uivezxGMsBBQORMb0znYbWzkWTWghVEB/Va32s5RBV2XqK6OBrCoHQKMFc+9K4ubLa2FXFJM c9mtRmD6BsvrBTdSj/0oiahRyIAqlXP0UDEbTEGo5vNpng9yKOdH+h05CxVd6v9mxCdEtxrUsSW1G 5Nu1zdE9k288+9TFHnrWmcXc7SDzJ8Pl0RCtWwS8KTx8xE4GQI/leEBab3Ix0St5Vjy1KzXSv6sj7 mYiIj/vlMUKZfuZNS072Vr6LEq1jSaXP6rx2xvCvvMALzpHWgITaNHGpo/TchrLTPjZVMojqDfg0o MaM8TaDQ==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1qhEki-00Bg0a-Q4; Fri, 15 Sep 2023 19:45:20 +0000 Date: Fri, 15 Sep 2023 20:45:20 +0100 From: Matthew Wilcox To: Pankaj Raghav Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, p.raghav@samsung.com, david@fromorbit.com, da.gomez@samsung.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, djwong@kernel.org, linux-mm@kvack.org, chandan.babu@oracle.com, mcgrof@kernel.org, gost.dev@samsung.com Subject: Re: [RFC 05/23] filemap: align index to mapping_min_order in filemap_range_has_page() Message-ID: References: <20230915183848.1018717-1-kernel@pankajraghav.com> <20230915183848.1018717-6-kernel@pankajraghav.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230915183848.1018717-6-kernel@pankajraghav.com> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Sep 15, 2023 at 08:38:30PM +0200, Pankaj Raghav wrote: > From: Luis Chamberlain > > page cache is mapping min_folio_order aligned. Use mapping min_folio_order > to align the start_byte and end_byte in filemap_range_has_page(). What goes wrong if you don't? Seems to me like it should work. > Signed-off-by: Luis Chamberlain > --- > mm/filemap.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/mm/filemap.c b/mm/filemap.c > index 2c47729dc8b0..4dee24b5b61c 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -477,9 +477,12 @@ EXPORT_SYMBOL(filemap_flush); > bool filemap_range_has_page(struct address_space *mapping, > loff_t start_byte, loff_t end_byte) > { > + unsigned int min_order = mapping_min_folio_order(mapping); > + unsigned int nrpages = 1UL << min_order; > + pgoff_t index = round_down(start_byte >> PAGE_SHIFT, nrpages); > struct folio *folio; > - XA_STATE(xas, &mapping->i_pages, start_byte >> PAGE_SHIFT); > - pgoff_t max = end_byte >> PAGE_SHIFT; > + XA_STATE(xas, &mapping->i_pages, index); > + pgoff_t max = round_down(end_byte >> PAGE_SHIFT, nrpages); > > if (end_byte < start_byte) > return false; > -- > 2.40.1 >