From patchwork Wed Feb 23 21:12:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trond Myklebust X-Patchwork-Id: 12757505 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 3F666C4332F for ; Wed, 23 Feb 2022 21:20:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242443AbiBWVUF (ORCPT ); Wed, 23 Feb 2022 16:20:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242403AbiBWVUD (ORCPT ); Wed, 23 Feb 2022 16:20:03 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C17824ECC9 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 5A7A7618A0 for ; Wed, 23 Feb 2022 21:19:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 908E8C340EC 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=YSlSxEp6sfdTAeiWJPOv6KCIoNl1N+23KqA1vIEZPNA=; h=From:To:Subject:Date:In-Reply-To:References:From; b=L4WIoPOHAW5mXdcL61OFcp1HZeuKh0q22RikZTM5ev9rW+3DYp0xskq7aMH7zMIku r5+J5T1o+KXTQKf9DkKZlb9bhzCNKqtFeZfk7EXbLWNF1R3nVTKrBwQsvSgiEKjlj4 VvckhG22YekPrp/r2DCEyjBHu9HUF7rPx3Zd7n7Z4Ip7b44Ieo4nToHfh59cdGldof TXqDlLxOjGIrnMBKS+weEC37gG10rpgtYpw6mU6tO1EC4hVDRmuIRZ5tLkXZ7xW1pX PJFqO5F13zur6w8h6x+QWlsJYO5esuIdvzv4fn6q6fLhfECY8hSWohWC9Xdsh2syDV VHsSNpZvekFSQ== From: trondmy@kernel.org To: linux-nfs@vger.kernel.org Subject: [PATCH v7 05/21] NFS: Store the change attribute in the directory page cache Date: Wed, 23 Feb 2022 16:12:49 -0500 Message-Id: <20220223211305.296816-6-trondmy@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220223211305.296816-5-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> <20220223211305.296816-5-trondmy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Trond Myklebust Use the change attribute and the first cookie in a directory page cache entry to validate that the page is up to date. Suggested-by: Benjamin Coddington Signed-off-by: Trond Myklebust --- fs/nfs/dir.c | 68 ++++++++++++++++++++++++++++------------------------ 1 file changed, 37 insertions(+), 31 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index f2258e926df2..5d9367d9b651 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -139,6 +139,7 @@ struct nfs_cache_array_entry { }; struct nfs_cache_array { + u64 change_attr; u64 last_cookie; unsigned int size; unsigned char page_full : 1, @@ -175,7 +176,8 @@ static void nfs_readdir_array_init(struct nfs_cache_array *array) memset(array, 0, sizeof(struct nfs_cache_array)); } -static void nfs_readdir_page_init_array(struct page *page, u64 last_cookie) +static void nfs_readdir_page_init_array(struct page *page, u64 last_cookie, + u64 change_attr) { struct nfs_cache_array *array; @@ -207,7 +209,7 @@ nfs_readdir_page_array_alloc(u64 last_cookie, gfp_t gfp_flags) { struct page *page = alloc_page(gfp_flags); if (page) - nfs_readdir_page_init_array(page, last_cookie); + nfs_readdir_page_init_array(page, last_cookie, 0); return page; } @@ -304,19 +306,44 @@ int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page) return ret; } +static bool nfs_readdir_page_cookie_match(struct page *page, u64 last_cookie, + u64 change_attr) +{ + struct nfs_cache_array *array = kmap_atomic(page); + int ret = true; + + if (array->change_attr != change_attr) + ret = false; + if (array->size > 0 && array->array[0].cookie != last_cookie) + ret = false; + kunmap_atomic(array); + return ret; +} + +static void nfs_readdir_page_unlock_and_put(struct page *page) +{ + unlock_page(page); + put_page(page); +} + static struct page *nfs_readdir_page_get_locked(struct address_space *mapping, pgoff_t index, u64 last_cookie) { struct page *page; + u64 change_attr; page = grab_cache_page(mapping, index); - if (page && !PageUptodate(page)) { - nfs_readdir_page_init_array(page, last_cookie); - if (invalidate_inode_pages2_range(mapping, index + 1, -1) < 0) - nfs_zap_mapping(mapping->host, mapping); - SetPageUptodate(page); + if (!page) + return NULL; + change_attr = inode_peek_iversion_raw(mapping->host); + if (PageUptodate(page)) { + if (nfs_readdir_page_cookie_match(page, last_cookie, + change_attr)) + return page; + nfs_readdir_clear_array(page); } - + nfs_readdir_page_init_array(page, last_cookie, change_attr); + SetPageUptodate(page); return page; } @@ -356,12 +383,6 @@ static void nfs_readdir_page_set_eof(struct page *page) kunmap_atomic(array); } -static void nfs_readdir_page_unlock_and_put(struct page *page) -{ - unlock_page(page); - put_page(page); -} - static struct page *nfs_readdir_page_get_next(struct address_space *mapping, pgoff_t index, u64 cookie) { @@ -418,16 +439,6 @@ static int nfs_readdir_search_for_pos(struct nfs_cache_array *array, return -EBADCOOKIE; } -static bool -nfs_readdir_inode_mapping_valid(struct nfs_inode *nfsi) -{ - if (nfsi->cache_validity & (NFS_INO_INVALID_CHANGE | - NFS_INO_INVALID_DATA)) - return false; - smp_rmb(); - return !test_bit(NFS_INO_INVALIDATING, &nfsi->flags); -} - static bool nfs_readdir_array_cookie_in_range(struct nfs_cache_array *array, u64 cookie) { @@ -456,8 +467,7 @@ static int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, struct nfs_inode *nfsi = NFS_I(file_inode(desc->file)); new_pos = nfs_readdir_page_offset(desc->page) + i; - if (desc->attr_gencount != nfsi->attr_gencount || - !nfs_readdir_inode_mapping_valid(nfsi)) { + if (desc->attr_gencount != nfsi->attr_gencount) { desc->duped = 0; desc->attr_gencount = nfsi->attr_gencount; } else if (new_pos < desc->prev_index) { @@ -1094,11 +1104,7 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx) * to either find the entry with the appropriate number or * revalidate the cookie. */ - if (ctx->pos == 0 || nfs_attribute_cache_expired(inode)) { - res = nfs_revalidate_mapping(inode, file->f_mapping); - if (res < 0) - goto out; - } + nfs_revalidate_inode(inode, NFS_INO_INVALID_CHANGE); res = -ENOMEM; desc = kzalloc(sizeof(*desc), GFP_KERNEL);