From patchwork Sun Feb 27 23:12:07 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trond Myklebust X-Patchwork-Id: 12762193 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 754BCC433EF for ; Sun, 27 Feb 2022 23:18:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232195AbiB0XTQ (ORCPT ); Sun, 27 Feb 2022 18:19:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42326 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232186AbiB0XTP (ORCPT ); Sun, 27 Feb 2022 18:19:15 -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 C8BD322527 for ; Sun, 27 Feb 2022 15:18:37 -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 C5AB5611D4 for ; Sun, 27 Feb 2022 23:18:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6BE57C340E9 for ; Sun, 27 Feb 2022 23:18:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1646003916; bh=F6cIFzb322lA5LYmOGHKbW31HBMZnxMHH/samvy5LRg=; h=From:To:Subject:Date:In-Reply-To:References:From; b=n+EbAYDEcWODmLs3lf5hxkfQ85Zpv80MVy8tg8j9e6RaMoNGO5n5FlfIiTXGhpa9p QOq6ddNRTh1jnDalzIbGwzTxF5AWoPVk3gEVGYgh0dZ7CHarBKDDpF52LCGhIl+tKs /Ed6IF2zgHGCx5GA9oJ0Wm4v58b6e/LIOkx2ssISblGqNoSabA+DA7OvQIwxLcRYMt Z+8v99cMY3bhe5Bpp+IgJqAtmJH1KPl9r2/Rhuz14cjQ5FKp1sQbfMzuh8WKtpa8og shWauK2OFF6vgpd7xEkbMJjeE0wH2zLe2Si0rCPORY08d00knlkP/8rMQWYlvcxXxw pNuW6wz56eHoQ== From: trondmy@kernel.org To: linux-nfs@vger.kernel.org Subject: [PATCH v9 07/27] NFS: Store the change attribute in the directory page cache Date: Sun, 27 Feb 2022 18:12:07 -0500 Message-Id: <20220227231227.9038-8-trondmy@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220227231227.9038-7-trondmy@kernel.org> References: <20220227231227.9038-1-trondmy@kernel.org> <20220227231227.9038-2-trondmy@kernel.org> <20220227231227.9038-3-trondmy@kernel.org> <20220227231227.9038-4-trondmy@kernel.org> <20220227231227.9038-5-trondmy@kernel.org> <20220227231227.9038-6-trondmy@kernel.org> <20220227231227.9038-7-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 6f0a38db6c37..bfb553c57274 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -140,6 +140,7 @@ struct nfs_cache_array_entry { }; struct nfs_cache_array { + u64 change_attr; u64 last_cookie; unsigned int size; unsigned char page_full : 1, @@ -176,12 +177,14 @@ 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; array = kmap_atomic(page); nfs_readdir_array_init(array); + array->change_attr = change_attr; array->last_cookie = last_cookie; array->cookies_are_ordered = 1; kunmap_atomic(array); @@ -208,7 +211,7 @@ 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; } @@ -305,19 +308,43 @@ int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page) return ret; } +static bool nfs_readdir_page_validate(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_validate(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; } @@ -357,12 +384,6 @@ 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) { @@ -419,16 +440,6 @@ 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) { @@ -457,8 +468,7 @@ 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) { @@ -1095,11 +1105,7 @@ 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);