From mboxrd@z Thu Jan 1 00:00:00 1970 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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_RED, 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 CC19DC433DB for ; Mon, 28 Dec 2020 14:28:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AED4D22573 for ; Mon, 28 Dec 2020 14:28:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2501859AbgL1O2H (ORCPT ); Mon, 28 Dec 2020 09:28:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:34806 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2503964AbgL1O1t (ORCPT ); Mon, 28 Dec 2020 09:27:49 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id A305E20715; Mon, 28 Dec 2020 14:27:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609165653; bh=Se0yAx/+GCP76IQO6UyKXtyTSG3emY9mc/wr5WGYCcs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ziw8LSwgymtONJiKhoXLzGirWx+SCxQAXFcLZSEKkB+fjt4BG2NXaFGN9/v1WfPk4 v87MpDB5hyfLZyY6+Cj4ZTDEAzKBXhgyyPCRuUXgIByd7K814lCI+Q4RFsXQy051Uq XSfS4iMehhZC4oYwCLqwRiE2tIEbop+eiE+A/QsE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Olga Kornievskaia , Chuck Lever , Trond Myklebust Subject: [PATCH 5.10 606/717] xprtrdma: Fix XDRBUF_SPARSE_PAGES support Date: Mon, 28 Dec 2020 13:50:04 +0100 Message-Id: <20201228125049.945106897@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228125020.963311703@linuxfoundation.org> References: <20201228125020.963311703@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chuck Lever commit 15261b9126cd5bb2ad8521da49d8f5c042d904c7 upstream. Olga K. observed that rpcrdma_marsh_req() allocates sparse pages only when it has determined that a Reply chunk is necessary. There are plenty of cases where no Reply chunk is needed, but the XDRBUF_SPARSE_PAGES flag is set. The result would be a crash in rpcrdma_inline_fixup() when it tries to copy parts of the received Reply into a missing page. To avoid crashing, handle sparse page allocation up front. Until XATTR support was added, this issue did not appear often because the only SPARSE_PAGES consumer always expected a reply large enough to always require a Reply chunk. Reported-by: Olga Kornievskaia Signed-off-by: Chuck Lever Cc: Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- net/sunrpc/xprtrdma/rpc_rdma.c | 40 +++++++++++++++++++++++++++++++--------- 1 file changed, 31 insertions(+), 9 deletions(-) --- a/net/sunrpc/xprtrdma/rpc_rdma.c +++ b/net/sunrpc/xprtrdma/rpc_rdma.c @@ -179,6 +179,31 @@ rpcrdma_nonpayload_inline(const struct r r_xprt->rx_ep->re_max_inline_recv; } +/* ACL likes to be lazy in allocating pages. For TCP, these + * pages can be allocated during receive processing. Not true + * for RDMA, which must always provision receive buffers + * up front. + */ +static noinline int +rpcrdma_alloc_sparse_pages(struct xdr_buf *buf) +{ + struct page **ppages; + int len; + + len = buf->page_len; + ppages = buf->pages + (buf->page_base >> PAGE_SHIFT); + while (len > 0) { + if (!*ppages) + *ppages = alloc_page(GFP_NOWAIT | __GFP_NOWARN); + if (!*ppages) + return -ENOBUFS; + ppages++; + len -= PAGE_SIZE; + } + + return 0; +} + /* Split @vec on page boundaries into SGEs. FMR registers pages, not * a byte range. Other modes coalesce these SGEs into a single MR * when they can. @@ -233,15 +258,6 @@ rpcrdma_convert_iovs(struct rpcrdma_xprt ppages = xdrbuf->pages + (xdrbuf->page_base >> PAGE_SHIFT); page_base = offset_in_page(xdrbuf->page_base); while (len) { - /* ACL likes to be lazy in allocating pages - ACLs - * are small by default but can get huge. - */ - if (unlikely(xdrbuf->flags & XDRBUF_SPARSE_PAGES)) { - if (!*ppages) - *ppages = alloc_page(GFP_NOWAIT | __GFP_NOWARN); - if (!*ppages) - return -ENOBUFS; - } seg->mr_page = *ppages; seg->mr_offset = (char *)page_base; seg->mr_len = min_t(u32, PAGE_SIZE - page_base, len); @@ -867,6 +883,12 @@ rpcrdma_marshal_req(struct rpcrdma_xprt __be32 *p; int ret; + if (unlikely(rqst->rq_rcv_buf.flags & XDRBUF_SPARSE_PAGES)) { + ret = rpcrdma_alloc_sparse_pages(&rqst->rq_rcv_buf); + if (ret) + return ret; + } + rpcrdma_set_xdrlen(&req->rl_hdrbuf, 0); xdr_init_encode(xdr, &req->rl_hdrbuf, rdmab_data(req->rl_rdmabuf), rqst);