From patchwork Mon Nov 2 18:06:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trond Myklebust X-Patchwork-Id: 11874855 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 3A89292C for ; Mon, 2 Nov 2020 18:17:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DF7420786 for ; Mon, 2 Nov 2020 18:17:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604341050; bh=XVXBt4Tj7nqalGynpZA6CSK0J9bdcHzViYb2QRauuk4=; h=From:To:Subject:Date:In-Reply-To:References:List-ID:From; b=jh8u0r8fn4cfupo8azN8XexKuYoMFlPn9e6AxXQPZO15CIDJWss13PnxThwmWK1C7 eGlAFQVAUnsfwTqfaCGHzEppP0tagQSrwhbpZekRDQiCDGyAJz2a5LK0Lz7RlxOBB+ G7Mp0PswRViQgUjXQHBvWmHUCN78akrm9ZBmAdCA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726283AbgKBSR2 (ORCPT ); Mon, 2 Nov 2020 13:17:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:40862 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726342AbgKBSR1 (ORCPT ); Mon, 2 Nov 2020 13:17:27 -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 5FE402222B for ; Mon, 2 Nov 2020 18:17:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604341046; bh=XVXBt4Tj7nqalGynpZA6CSK0J9bdcHzViYb2QRauuk4=; h=From:To:Subject:Date:In-Reply-To:References:From; b=k6rLGh6GwPmS8ff+9KocyWM4cmzA+7QX3RzZc6qAO8zRP9XueXGGkDwsIckEakatQ 3qfc9z669Y1Fls5fZCrlPU7GZwpRCQh2D++oxAISkDucrGzJrnw1AHG1ZR2Ko+ZPNd X5MzSWQ4uoBPdJhaQgkFRvw5p0P0Tj3nhgyt3b64= From: trondmy@kernel.org To: linux-nfs@vger.kernel.org Subject: [PATCH 12/12] NFS: Reduce readdir stack usage Date: Mon, 2 Nov 2020 13:06:58 -0500 Message-Id: <20201102180658.6218-13-trondmy@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201102180658.6218-12-trondmy@kernel.org> References: <20201102180658.6218-1-trondmy@kernel.org> <20201102180658.6218-2-trondmy@kernel.org> <20201102180658.6218-3-trondmy@kernel.org> <20201102180658.6218-4-trondmy@kernel.org> <20201102180658.6218-5-trondmy@kernel.org> <20201102180658.6218-6-trondmy@kernel.org> <20201102180658.6218-7-trondmy@kernel.org> <20201102180658.6218-8-trondmy@kernel.org> <20201102180658.6218-9-trondmy@kernel.org> <20201102180658.6218-10-trondmy@kernel.org> <20201102180658.6218-11-trondmy@kernel.org> <20201102180658.6218-12-trondmy@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Trond Myklebust The descriptor and the struct nfs_entry are both large structures, so don't allocate them from the stack. Signed-off-by: Trond Myklebust --- fs/nfs/dir.c | 88 +++++++++++++++++++++++++++------------------------- 1 file changed, 46 insertions(+), 42 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index a2cebd365948..966e8fc6c9b7 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -144,7 +144,7 @@ struct nfs_cache_array { struct nfs_cache_array_entry array[]; }; -typedef struct nfs_readdir_descriptor { +struct nfs_readdir_descriptor { struct file *file; struct page *page; struct dir_context *ctx; @@ -163,7 +163,7 @@ typedef struct nfs_readdir_descriptor { signed char duped; bool plus; bool eof; -} nfs_readdir_descriptor_t; +}; static void nfs_readdir_array_init(struct nfs_cache_array *array) { @@ -358,8 +358,8 @@ bool nfs_readdir_use_cookie(const struct file *filp) return true; } -static -int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc) +static int nfs_readdir_search_for_pos(struct nfs_cache_array *array, + struct nfs_readdir_descriptor *desc) { loff_t diff = desc->ctx->pos - desc->current_index; unsigned int index; @@ -390,8 +390,8 @@ nfs_readdir_inode_mapping_valid(struct nfs_inode *nfsi) return !test_bit(NFS_INO_INVALIDATING, &nfsi->flags); } -static -int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc) +static int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, + struct nfs_readdir_descriptor *desc) { int i; loff_t new_pos; @@ -439,8 +439,7 @@ int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_des return status; } -static -int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc) +static int nfs_readdir_search_array(struct nfs_readdir_descriptor *desc) { struct nfs_cache_array *array; int status; @@ -493,7 +492,7 @@ static int nfs_readdir_xdr_filler(struct nfs_readdir_descriptor *desc, return error; } -static int xdr_decode(nfs_readdir_descriptor_t *desc, +static int xdr_decode(struct nfs_readdir_descriptor *desc, struct nfs_entry *entry, struct xdr_stream *xdr) { struct inode *inode = file_inode(desc->file); @@ -757,27 +756,28 @@ static struct page **nfs_readdir_alloc_pages(size_t npages) return NULL; } -static -int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode) +static int nfs_readdir_xdr_to_array(struct nfs_readdir_descriptor *desc, + struct page *page, struct inode *inode) { struct page **pages; - struct nfs_entry entry; + struct nfs_entry *entry; size_t array_size; size_t dtsize = NFS_SERVER(inode)->dtsize; int status = -ENOMEM; - entry.prev_cookie = 0; - entry.cookie = nfs_readdir_page_last_cookie(page); - entry.eof = 0; - entry.fh = nfs_alloc_fhandle(); - entry.fattr = nfs_alloc_fattr(); - entry.server = NFS_SERVER(inode); - if (entry.fh == NULL || entry.fattr == NULL) + entry = kzalloc(sizeof(*entry), GFP_KERNEL); + if (!entry) + return -ENOMEM; + entry->cookie = nfs_readdir_page_last_cookie(page); + entry->fh = nfs_alloc_fhandle(); + entry->fattr = nfs_alloc_fattr(); + entry->server = NFS_SERVER(inode); + if (entry->fh == NULL || entry->fattr == NULL) goto out; - entry.label = nfs4_label_alloc(NFS_SERVER(inode), GFP_NOWAIT); - if (IS_ERR(entry.label)) { - status = PTR_ERR(entry.label); + entry->label = nfs4_label_alloc(NFS_SERVER(inode), GFP_NOWAIT); + if (IS_ERR(entry->label)) { + status = PTR_ERR(entry->label); goto out; } @@ -788,7 +788,7 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, do { unsigned int pglen; - status = nfs_readdir_xdr_filler(desc, entry.cookie, + status = nfs_readdir_xdr_filler(desc, entry->cookie, pages, dtsize); if (status < 0) break; @@ -799,15 +799,16 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, break; } - status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen); + status = nfs_readdir_page_filler(desc, entry, pages, page, pglen); } while (!status && nfs_readdir_page_needs_filling(page)); nfs_readdir_free_pages(pages, array_size); out_release_label: - nfs4_label_free(entry.label); + nfs4_label_free(entry->label); out: - nfs_free_fattr(entry.fattr); - nfs_free_fhandle(entry.fh); + nfs_free_fattr(entry->fattr); + nfs_free_fhandle(entry->fh); + kfree(entry); return status; } @@ -829,8 +830,7 @@ nfs_readdir_page_get_cached(struct nfs_readdir_descriptor *desc) * Returns 0 if desc->dir_cookie was found on page desc->page_index * and locks the page to prevent removal from the page cache. */ -static -int find_and_lock_cache_page(nfs_readdir_descriptor_t *desc) +static int find_and_lock_cache_page(struct nfs_readdir_descriptor *desc) { struct inode *inode = file_inode(desc->file); struct nfs_inode *nfsi = NFS_I(inode); @@ -856,8 +856,7 @@ int find_and_lock_cache_page(nfs_readdir_descriptor_t *desc) } /* Search for desc->dir_cookie from the beginning of the page cache */ -static inline -int readdir_search_pagecache(nfs_readdir_descriptor_t *desc) +static int readdir_search_pagecache(struct nfs_readdir_descriptor *desc) { int res; @@ -922,8 +921,7 @@ static void nfs_do_filldir(struct nfs_readdir_descriptor *desc) * we should already have a complete representation of the * directory in the page cache by the time we get here. */ -static inline -int uncached_readdir(nfs_readdir_descriptor_t *desc) +static int uncached_readdir(struct nfs_readdir_descriptor *desc) { struct page *page = NULL; int status; @@ -968,13 +966,8 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx) struct dentry *dentry = file_dentry(file); struct inode *inode = d_inode(dentry); struct nfs_open_dir_context *dir_ctx = file->private_data; - nfs_readdir_descriptor_t my_desc = { - .file = file, - .ctx = ctx, - .plus = nfs_use_readdirplus(inode, ctx), - }, - *desc = &my_desc; - int res = 0; + struct nfs_readdir_descriptor *desc; + int res; dfprintk(FILE, "NFS: readdir(%pD2) starting at cookie %llu\n", file, (long long)ctx->pos); @@ -986,10 +979,19 @@ 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)) + if (ctx->pos == 0 || nfs_attribute_cache_expired(inode)) { res = nfs_revalidate_mapping(inode, file->f_mapping); - if (res < 0) + if (res < 0) + goto out; + } + + res = -ENOMEM; + desc = kzalloc(sizeof(*desc), GFP_KERNEL); + if (!desc) goto out; + desc->file = file; + desc->ctx = ctx; + desc->plus = nfs_use_readdirplus(inode, ctx); spin_lock(&file->f_lock); desc->dir_cookie = dir_ctx->dir_cookie; @@ -1035,6 +1037,8 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx) dir_ctx->attr_gencount = desc->attr_gencount; spin_unlock(&file->f_lock); + kfree(desc); + out: dfprintk(FILE, "NFS: readdir(%pD2) returns %d\n", file, res); return res;