From patchwork Tue Nov 10 21:37:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trond Myklebust X-Patchwork-Id: 11895459 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EFFF815E6 for ; Tue, 10 Nov 2020 21:48:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C63FD20797 for ; Tue, 10 Nov 2020 21:48:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="vr1T4jDm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731981AbgKJVsG (ORCPT ); Tue, 10 Nov 2020 16:48:06 -0500 Received: from mail.kernel.org ([198.145.29.99]:43190 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732002AbgKJVsE (ORCPT ); Tue, 10 Nov 2020 16:48:04 -0500 Received: from localhost.localdomain (c-68-36-133-222.hsd1.mi.comcast.net [68.36.133.222]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6111B20781 for ; Tue, 10 Nov 2020 21:48:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605044883; bh=PZrE/PvcVjZKdZ3mAu7JFmys+cQonAS+F+T3rcSDTm0=; h=From:To:Subject:Date:In-Reply-To:References:From; b=vr1T4jDm7vuaiHuYxu3OAdgnQ9XiAd+vXCmJ40cQMp9Wcgell4WvcRpDhf6byv9AX g7irg49xvYDXTRS7c6l1It2F+JAL3dWqJ3/AQRpLkJP/526ueV2DySP5Bo2xIB25Ho npb/Lcu1UknwJm+f5k3b1RQXs81dVK9lQpLG7GFE= From: trondmy@kernel.org To: linux-nfs@vger.kernel.org Subject: [PATCH v5 21/22] NFS: Reduce number of RPC calls when doing uncached readdir Date: Tue, 10 Nov 2020 16:37:40 -0500 Message-Id: <20201110213741.860745-22-trondmy@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201110213741.860745-21-trondmy@kernel.org> References: <20201110213741.860745-1-trondmy@kernel.org> <20201110213741.860745-2-trondmy@kernel.org> <20201110213741.860745-3-trondmy@kernel.org> <20201110213741.860745-4-trondmy@kernel.org> <20201110213741.860745-5-trondmy@kernel.org> <20201110213741.860745-6-trondmy@kernel.org> <20201110213741.860745-7-trondmy@kernel.org> <20201110213741.860745-8-trondmy@kernel.org> <20201110213741.860745-9-trondmy@kernel.org> <20201110213741.860745-10-trondmy@kernel.org> <20201110213741.860745-11-trondmy@kernel.org> <20201110213741.860745-12-trondmy@kernel.org> <20201110213741.860745-13-trondmy@kernel.org> <20201110213741.860745-14-trondmy@kernel.org> <20201110213741.860745-15-trondmy@kernel.org> <20201110213741.860745-16-trondmy@kernel.org> <20201110213741.860745-17-trondmy@kernel.org> <20201110213741.860745-18-trondmy@kernel.org> <20201110213741.860745-19-trondmy@kernel.org> <20201110213741.860745-20-trondmy@kernel.org> <20201110213741.860745-21-trondmy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Trond Myklebust If we're doing uncached readdir, allocate multiple pages in order to try to avoid duplicate RPC calls for the same getdents() call. Signed-off-by: Trond Myklebust Reviewed-by: Benjamin Coddington --- fs/nfs/dir.c | 105 +++++++++++++++++++++++++++++++++------------------ 1 file changed, 69 insertions(+), 36 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index b6c3501e8f61..93c6f22cdc62 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -199,6 +199,23 @@ void nfs_readdir_clear_array(struct page *page) kunmap_atomic(array); } +static struct page * +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); + return page; +} + +static void nfs_readdir_page_array_free(struct page *page) +{ + if (page) { + nfs_readdir_clear_array(page); + put_page(page); + } +} + static void nfs_readdir_array_set_eof(struct nfs_cache_array *array) { array->page_is_eof = 1; @@ -694,12 +711,14 @@ void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry, static int nfs_readdir_page_filler(struct nfs_readdir_descriptor *desc, struct nfs_entry *entry, struct page **xdr_pages, - struct page *fillme, unsigned int buflen) + unsigned int buflen, + struct page **arrays, + size_t narrays) { struct address_space *mapping = desc->file->f_mapping; struct xdr_stream stream; struct xdr_buf buf; - struct page *scratch, *new, *page = fillme; + struct page *scratch, *new, *page = *arrays; int status; scratch = alloc_page(GFP_KERNEL); @@ -725,15 +744,25 @@ static int nfs_readdir_page_filler(struct nfs_readdir_descriptor *desc, if (status != -ENOSPC) continue; - if (page->mapping != mapping) - break; - new = nfs_readdir_page_get_next(mapping, page->index + 1, - entry->prev_cookie); - if (!new) - break; - if (page != fillme) - nfs_readdir_page_unlock_and_put(page); - page = new; + if (page->mapping != mapping) { + if (!--narrays) + break; + new = nfs_readdir_page_array_alloc(entry->prev_cookie, + GFP_KERNEL); + if (!new) + break; + arrays++; + *arrays = page = new; + } else { + new = nfs_readdir_page_get_next(mapping, + page->index + 1, + entry->prev_cookie); + if (!new) + break; + if (page != *arrays) + nfs_readdir_page_unlock_and_put(page); + page = new; + } status = nfs_readdir_add_to_array(entry, page); } while (!status && !entry->eof); @@ -750,7 +779,7 @@ static int nfs_readdir_page_filler(struct nfs_readdir_descriptor *desc, break; } - if (page != fillme) + if (page != *arrays) nfs_readdir_page_unlock_and_put(page); put_page(scratch); @@ -790,10 +819,11 @@ static struct page **nfs_readdir_alloc_pages(size_t npages) } static int nfs_readdir_xdr_to_array(struct nfs_readdir_descriptor *desc, - struct page *page, __be32 *verf_arg, - __be32 *verf_res) + __be32 *verf_arg, __be32 *verf_res, + struct page **arrays, size_t narrays) { struct page **pages; + struct page *page = *arrays; struct nfs_entry *entry; size_t array_size; struct inode *inode = file_inode(desc->file); @@ -835,7 +865,8 @@ static int nfs_readdir_xdr_to_array(struct nfs_readdir_descriptor *desc, break; } - status = nfs_readdir_page_filler(desc, entry, pages, page, pglen); + status = nfs_readdir_page_filler(desc, entry, pages, pglen, + arrays, narrays); } while (!status && nfs_readdir_page_needs_filling(page)); nfs_readdir_free_pages(pages, array_size); @@ -884,8 +915,8 @@ static int find_and_lock_cache_page(struct nfs_readdir_descriptor *desc) if (!desc->page) return -ENOMEM; if (nfs_readdir_page_needs_filling(desc->page)) { - res = nfs_readdir_xdr_to_array(desc, desc->page, - nfsi->cookieverf, verf); + res = nfs_readdir_xdr_to_array(desc, nfsi->cookieverf, verf, + &desc->page, 1); if (res < 0) { nfs_readdir_page_unlock_and_put_cached(desc); if (res == -EBADCOOKIE || res == -ENOTSYNC) { @@ -976,37 +1007,39 @@ static void nfs_do_filldir(struct nfs_readdir_descriptor *desc) */ static int uncached_readdir(struct nfs_readdir_descriptor *desc) { - struct page *page = NULL; + struct page **arrays; + size_t i, sz = 512; __be32 verf[NFS_DIR_VERIFIER_SIZE]; - int status; + int status = -ENOMEM; - dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n", + dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %llu\n", (unsigned long long)desc->dir_cookie); - page = alloc_page(GFP_HIGHUSER); - if (!page) { - status = -ENOMEM; + arrays = kcalloc(sz, sizeof(*arrays), GFP_KERNEL); + if (!arrays) + goto out; + arrays[0] = nfs_readdir_page_array_alloc(desc->dir_cookie, GFP_KERNEL); + if (!arrays[0]) goto out; - } desc->page_index = 0; desc->last_cookie = desc->dir_cookie; - desc->page = page; desc->duped = 0; - nfs_readdir_page_init_array(page, desc->dir_cookie); - status = nfs_readdir_xdr_to_array(desc, page, desc->verf, verf); - if (status < 0) - goto out_release; + status = nfs_readdir_xdr_to_array(desc, desc->verf, verf, arrays, sz); - nfs_do_filldir(desc); + for (i = 0; !desc->eof && i < sz && arrays[i]; i++) { + desc->page = arrays[i]; + nfs_do_filldir(desc); + } + desc->page = NULL; - out_release: - nfs_readdir_clear_array(desc->page); - nfs_readdir_page_put(desc); - out: - dfprintk(DIRCACHE, "NFS: %s: returns %d\n", - __func__, status); + + for (i = 0; i < sz && arrays[i]; i++) + nfs_readdir_page_array_free(arrays[i]); +out: + kfree(arrays); + dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __func__, status); return status; }