From patchwork Wed Dec 2 00:34:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frank van der Linden X-Patchwork-Id: 11944417 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5519BC64E90 for ; Wed, 2 Dec 2020 00:35:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECAE6204FD for ; Wed, 2 Dec 2020 00:35:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726655AbgLBAfS (ORCPT ); Tue, 1 Dec 2020 19:35:18 -0500 Received: from smtp-fw-6002.amazon.com ([52.95.49.90]:54902 "EHLO smtp-fw-6002.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726484AbgLBAfR (ORCPT ); Tue, 1 Dec 2020 19:35:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1606869317; x=1638405317; h=from:to:cc:subject:date:message-id:mime-version; bh=NM9uzIA6eqTdAxM6MN04gnMaktbZtOmkPWI+E9wYDLM=; b=LIeM/eykvaSRYvuWiZiBlp2H62TsdARrZhqQPXdSwAaDbsFET2KFvFXl AL94DhwtJtlVV6/bLgsUgZpyP0BnLxfpjfcy+WrWh8L2zPWQv90IpNIb0 r/yt7QnqZSgVQz3ttePh9aHK6AVaiUXJwk8D4RGzbWJQaCafaXFd7I7o9 Y=; X-IronPort-AV: E=Sophos;i="5.78,385,1599523200"; d="scan'208";a="68473683" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-1a-715bee71.us-east-1.amazon.com) ([10.43.8.2]) by smtp-border-fw-out-6002.iad6.amazon.com with ESMTP; 02 Dec 2020 00:34:15 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-1a-715bee71.us-east-1.amazon.com (Postfix) with ESMTPS id C32F4A1F65; Wed, 2 Dec 2020 00:34:12 +0000 (UTC) Received: from EX13D13UWB004.ant.amazon.com (10.43.161.218) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 2 Dec 2020 00:34:11 +0000 Received: from EX13MTAUWB001.ant.amazon.com (10.43.161.207) by EX13D13UWB004.ant.amazon.com (10.43.161.218) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 2 Dec 2020 00:34:11 +0000 Received: from dev-dsk-fllinden-2c-c1893d73.us-west-2.amazon.com (172.23.141.97) by mail-relay.amazon.com (10.43.161.249) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Wed, 2 Dec 2020 00:34:11 +0000 Received: by dev-dsk-fllinden-2c-c1893d73.us-west-2.amazon.com (Postfix, from userid 6262777) id D17B4C1321; Wed, 2 Dec 2020 00:34:11 +0000 (UTC) From: Frank van der Linden To: , , CC: , , Frank van der Linden Subject: [PATCH v2] NFSv4.2: improve page handling for GETXATTR Date: Wed, 2 Dec 2020 00:34:11 +0000 Message-ID: <20201202003411.659-1-fllinden@amazon.com> X-Mailer: git-send-email 2.16.6 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org XDRBUF_SPARSE_PAGES can cause problems for the RDMA transport, and it's easy enough to allocate enough pages for the request up front, so do that. Also, since we've allocated the pages anyway, use the full page aligned length for the receive buffer. This will allow caching of valid replies that are too large for the caller, but that still fit in the allocated pages. Signed-off-by: Frank van der Linden --- fs/nfs/nfs42proc.c | 47 +++++++++++++++++++++++++++++++++++----------- fs/nfs/nfs42xdr.c | 14 ++++++++------ 2 files changed, 44 insertions(+), 17 deletions(-) diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c index faa673667fce..378a9edf9de9 100644 --- a/fs/nfs/nfs42proc.c +++ b/fs/nfs/nfs42proc.c @@ -1173,14 +1173,12 @@ static int _nfs42_proc_setxattr(struct inode *inode, const char *name, } static ssize_t _nfs42_proc_getxattr(struct inode *inode, const char *name, - void *buf, size_t buflen) + void *buf, size_t buflen, struct page **pages, + size_t plen) { struct nfs_server *server = NFS_SERVER(inode); - struct page *pages[NFS4XATTR_MAXPAGES] = {}; struct nfs42_getxattrargs arg = { .fh = NFS_FH(inode), - .xattr_pages = pages, - .xattr_len = buflen, .xattr_name = name, }; struct nfs42_getxattrres res; @@ -1189,7 +1187,10 @@ static ssize_t _nfs42_proc_getxattr(struct inode *inode, const char *name, .rpc_argp = &arg, .rpc_resp = &res, }; - int ret, np; + ssize_t ret; + + arg.xattr_len = plen; + arg.xattr_pages = pages; ret = nfs4_call_sync(server->client, server, &msg, &arg.seq_args, &res.seq_res, 0); @@ -1214,10 +1215,6 @@ static ssize_t _nfs42_proc_getxattr(struct inode *inode, const char *name, _copy_from_pages(buf, pages, 0, res.xattr_len); } - np = DIV_ROUND_UP(res.xattr_len, PAGE_SIZE); - while (--np >= 0) - __free_page(pages[np]); - return res.xattr_len; } @@ -1294,16 +1291,44 @@ ssize_t nfs42_proc_getxattr(struct inode *inode, const char *name, void *buf, size_t buflen) { struct nfs4_exception exception = { }; - ssize_t err; + ssize_t err, np, i; + struct page **pages; + np = nfs_page_array_len(0, buflen ?: XATTR_SIZE_MAX); + pages = kmalloc_array(np, sizeof(*pages), GFP_KERNEL); + if (!pages) + return -ENOMEM; + + for (i = 0; i < np; i++) { + pages[i] = alloc_page(GFP_KERNEL); + if (!pages[i]) { + np = i + 1; + goto out; + } + } + + /* + * The GETXATTR op has no length field in the call, and the + * xattr data is at the end of the reply. + * + * There is no downside in using the page-aligned length. It will + * allow receiving and caching xattrs that are too large for the + * caller but still fit in the page-rounded value. + */ do { - err = _nfs42_proc_getxattr(inode, name, buf, buflen); + err = _nfs42_proc_getxattr(inode, name, buf, buflen, + pages, np * PAGE_SIZE); if (err >= 0) break; err = nfs4_handle_exception(NFS_SERVER(inode), err, &exception); } while (exception.retry); +out: + while (--np >= 0) + __free_page(pages[np]); + kfree(pages); + return err; } diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c index 6e060a88f98c..f4eef4c49868 100644 --- a/fs/nfs/nfs42xdr.c +++ b/fs/nfs/nfs42xdr.c @@ -489,6 +489,12 @@ static int decode_getxattr(struct xdr_stream *xdr, return -EIO; len = be32_to_cpup(p); + + /* + * Only check against the page length here. The actual + * requested length may be smaller, but that is only + * checked against after possibly caching a valid reply. + */ if (len > req->rq_rcv_buf.page_len) return -ERANGE; @@ -1476,18 +1482,14 @@ static void nfs4_xdr_enc_getxattr(struct rpc_rqst *req, struct xdr_stream *xdr, struct compound_hdr hdr = { .minorversion = nfs4_xdr_minorversion(&args->seq_args), }; - size_t plen; encode_compound_hdr(xdr, req, &hdr); encode_sequence(xdr, &args->seq_args, &hdr); encode_putfh(xdr, args->fh, &hdr); encode_getxattr(xdr, args->xattr_name, &hdr); - plen = args->xattr_len ? args->xattr_len : XATTR_SIZE_MAX; - - rpc_prepare_reply_pages(req, args->xattr_pages, 0, plen, - hdr.replen); - req->rq_rcv_buf.flags |= XDRBUF_SPARSE_PAGES; + rpc_prepare_reply_pages(req, args->xattr_pages, 0, + args->xattr_len, hdr.replen); encode_nops(&hdr); }