From patchwork Wed Feb 23 21:12:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trond Myklebust X-Patchwork-Id: 12757507 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 61EF5C43219 for ; Wed, 23 Feb 2022 21:20:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242398AbiBWVUC (ORCPT ); Wed, 23 Feb 2022 16:20:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51922 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242403AbiBWVUC (ORCPT ); Wed, 23 Feb 2022 16:20:02 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58D6C4ECC7 for ; Wed, 23 Feb 2022 13:19:34 -0800 (PST) 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 E81D56189F for ; Wed, 23 Feb 2022 21:19:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27877C340E7 for ; Wed, 23 Feb 2022 21:19:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1645651173; bh=BDtVy5SNX6exg3u/FD6tPHlS7Ace5WAEZPBUVrHFAsI=; h=From:To:Subject:Date:In-Reply-To:References:From; b=HY7kUNRmMBazv8m5jd2YrPEMLakbDqEHepHDOqD+IOTFqFbiMHYN8ETC7z6PpKbzw POC1eWGMhc2oyB213GNo1qt4KeoQCHhvm7TnnhJdCyJvu4YDLL3coyRlw8QbbUOcOC 5lADKXhR0vEUp7n3QeJu7jqOm7EQ4aHv0/bkpF/dVoucuJWjLGqphQhBDmRnHq9TUA v0JHV6x+tMZNssRbcDXWpmO0AYc5x+IVZYolYdxcHHzncY7dCA1ifOLt4/QGZnNCsU qKO1poxbkjOqQdZeS7B73YDIgHEa93/PXj8aMmxs4dxkWoN+l4QhGWlDHH1qUXbU1r qL1aSWbM2nbyg== From: trondmy@kernel.org To: linux-nfs@vger.kernel.org Subject: [PATCH v7 04/21] NFS: Calculate page offsets algorithmically Date: Wed, 23 Feb 2022 16:12:48 -0500 Message-Id: <20220223211305.296816-5-trondmy@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220223211305.296816-4-trondmy@kernel.org> References: <20220223211305.296816-1-trondmy@kernel.org> <20220223211305.296816-2-trondmy@kernel.org> <20220223211305.296816-3-trondmy@kernel.org> <20220223211305.296816-4-trondmy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Trond Myklebust Instead of relying on counting the page offsets as we walk through the page cache, switch to calculating them algorithmically. Signed-off-by: Trond Myklebust --- fs/nfs/dir.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 8f17aaebcd77..f2258e926df2 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -248,17 +248,20 @@ static const char *nfs_readdir_copy_name(const char *name, unsigned int len) return ret; } +static size_t nfs_readdir_array_maxentries(void) +{ + return (PAGE_SIZE - sizeof(struct nfs_cache_array)) / + sizeof(struct nfs_cache_array_entry); +} + /* * Check that the next array entry lies entirely within the page bounds */ static int nfs_readdir_array_can_expand(struct nfs_cache_array *array) { - struct nfs_cache_array_entry *cache_entry; - if (array->page_full) return -ENOSPC; - cache_entry = &array->array[array->size + 1]; - if ((char *)cache_entry - (char *)array > PAGE_SIZE) { + if (array->size == nfs_readdir_array_maxentries()) { array->page_full = 1; return -ENOSPC; } @@ -317,6 +320,11 @@ static struct page *nfs_readdir_page_get_locked(struct address_space *mapping, return page; } +static loff_t nfs_readdir_page_offset(struct page *page) +{ + return (loff_t)page->index * (loff_t)nfs_readdir_array_maxentries(); +} + static u64 nfs_readdir_page_last_cookie(struct page *page) { struct nfs_cache_array *array; @@ -447,7 +455,7 @@ static int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, if (array->array[i].cookie == desc->dir_cookie) { struct nfs_inode *nfsi = NFS_I(file_inode(desc->file)); - new_pos = desc->current_index + i; + new_pos = nfs_readdir_page_offset(desc->page) + i; if (desc->attr_gencount != nfsi->attr_gencount || !nfs_readdir_inode_mapping_valid(nfsi)) { desc->duped = 0;