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 3D567C77B71 for ; Tue, 18 Apr 2023 06:50:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229734AbjDRGur (ORCPT ); Tue, 18 Apr 2023 02:50:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229527AbjDRGuq (ORCPT ); Tue, 18 Apr 2023 02:50:46 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5BEB1C9; Mon, 17 Apr 2023 23:50:45 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0323D62465; Tue, 18 Apr 2023 06:50:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29928C433EF; Tue, 18 Apr 2023 06:50:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1681800644; bh=m0aoQNzOmb6TzmGaMXcg9PrpCa/tOrj2DkkReGTrODY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OYDrr4xiq+8nSUCv+wKkztoqXRBa/knMwzmG2ST2X+eNUT0HMJgrX80BpFtXs6vG8 MHHUXMdrBXEDU3/dW3e0SVHyZhUfjHn2M8UpRAMuainKwkxrsC6bQ3Ni88jx+XFwk0 dItRC892uFizxvAYlKkf0NUBnJjULlp91DLcB9z9qrswdv+twrSTidxith+4qCE8ih fS0Zg29kuvw8UdEBwJNCgxRgrUyJBh6B4FLCT+I4J1+V4vGeI7I6lDJm9VFjoOeYdU kBmB2f5Z5gc1cuDJpRScevR0IxpCl301NETVA3fA2aVaIjOA30ECF4X0KjNN6sH6qM 2LNgUPU23r5iQ== Date: Mon, 17 Apr 2023 23:50:42 -0700 From: Eric Biggers To: "Matthew Wilcox (Oracle)" Cc: tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v2 29/29] ext4: Use a folio in ext4_read_merkle_tree_page Message-ID: <20230418065042.GA121074@quark.localdomain> References: <20230324180129.1220691-1-willy@infradead.org> <20230324180129.1220691-30-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230324180129.1220691-30-willy@infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hi Matthew, On Fri, Mar 24, 2023 at 06:01:29PM +0000, Matthew Wilcox (Oracle) wrote: > This is an implementation of fsverity_operations read_merkle_tree_page, > so it must still return the precise page asked for, but we can use the > folio API to reduce the number of conversions between folios & pages. > > Signed-off-by: Matthew Wilcox (Oracle) > --- > fs/ext4/verity.c | 14 +++++++------- > 1 file changed, 7 insertions(+), 7 deletions(-) > > diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c > index afe847c967a4..3b01247066dd 100644 > --- a/fs/ext4/verity.c > +++ b/fs/ext4/verity.c > @@ -361,21 +361,21 @@ static struct page *ext4_read_merkle_tree_page(struct inode *inode, > pgoff_t index, > unsigned long num_ra_pages) > { > - struct page *page; > + struct folio *folio; > > index += ext4_verity_metadata_pos(inode) >> PAGE_SHIFT; > > - page = find_get_page_flags(inode->i_mapping, index, FGP_ACCESSED); > - if (!page || !PageUptodate(page)) { > + folio = __filemap_get_folio(inode->i_mapping, index, FGP_ACCESSED, 0); > + if (!folio || !folio_test_uptodate(folio)) { > DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index); > > - if (page) > - put_page(page); > + if (folio) > + folio_put(folio); > else if (num_ra_pages > 1) > page_cache_ra_unbounded(&ractl, num_ra_pages, 0); > - page = read_mapping_page(inode->i_mapping, index, NULL); > + folio = read_mapping_folio(inode->i_mapping, index, NULL); > } > - return page; > + return folio_file_page(folio, index); This is not working at all, since it dereferences ERR_PTR(-ENOENT). I think it needs: diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c index 3b01247066dd..dbc655a6c443 100644 --- a/fs/ext4/verity.c +++ b/fs/ext4/verity.c @@ -366,15 +366,17 @@ static struct page *ext4_read_merkle_tree_page(struct inode *inode, index += ext4_verity_metadata_pos(inode) >> PAGE_SHIFT; folio = __filemap_get_folio(inode->i_mapping, index, FGP_ACCESSED, 0); - if (!folio || !folio_test_uptodate(folio)) { + if (folio == ERR_PTR(-ENOENT) || !folio_test_uptodate(folio)) { DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index); - if (folio) + if (!IS_ERR(folio)) folio_put(folio); else if (num_ra_pages > 1) page_cache_ra_unbounded(&ractl, num_ra_pages, 0); folio = read_mapping_folio(inode->i_mapping, index, NULL); } + if (IS_ERR(folio)) + return ERR_CAST(folio); return folio_file_page(folio, index); }