From patchwork Fri Sep 18 12:50:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: He Zhe X-Patchwork-Id: 11785247 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 AF6486CB for ; Fri, 18 Sep 2020 15:00:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A046D2073A for ; Fri, 18 Sep 2020 15:00:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726154AbgIRPA0 (ORCPT ); Fri, 18 Sep 2020 11:00:26 -0400 Received: from mail1.windriver.com ([147.11.146.13]:61950 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726130AbgIRPA0 (ORCPT ); Fri, 18 Sep 2020 11:00:26 -0400 X-Greylist: delayed 7316 seconds by postgrey-1.27 at vger.kernel.org; Fri, 18 Sep 2020 11:00:12 EDT Received: from ALA-HCB.corp.ad.wrs.com (ala-hcb.corp.ad.wrs.com [147.11.189.41]) by mail1.windriver.com (8.15.2/8.15.2) with ESMTPS id 08ICvm7X029634 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Fri, 18 Sep 2020 05:57:49 -0700 (PDT) Received: from pek-lpg-core2.corp.ad.wrs.com (128.224.153.41) by ALA-HCB.corp.ad.wrs.com (147.11.189.41) with Microsoft SMTP Server id 14.3.487.0; Fri, 18 Sep 2020 05:57:27 -0700 From: To: , , , , , , , , , Subject: [PATCH] SUNRPC: Flush dcache only when receiving more seeking Date: Fri, 18 Sep 2020 20:50:52 +0800 Message-ID: <20200918125052.2493006-1-zhe.he@windriver.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: He Zhe commit ca07eda33e01 ("SUNRPC: Refactor svc_recvfrom()") introduces svc_flush_bvec to after sock_recvmsg, but sometimes we receive less than we seek, which triggers the following warning. WARNING: CPU: 0 PID: 18266 at include/linux/bvec.h:101 bvec_iter_advance+0x44/0xa8 Attempted to advance past end of bvec iter Modules linked in: sch_fq_codel openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 CPU: 1 PID: 18266 Comm: nfsd Not tainted 5.9.0-rc5 #1 Hardware name: Xilinx Zynq Platform [<80112ec0>] (unwind_backtrace) from [<8010c3a8>] (show_stack+0x18/0x1c) [<8010c3a8>] (show_stack) from [<80755214>] (dump_stack+0x9c/0xd0) [<80755214>] (dump_stack) from [<80125e64>] (__warn+0xdc/0xf4) [<80125e64>] (__warn) from [<80126244>] (warn_slowpath_fmt+0x84/0xac) [<80126244>] (warn_slowpath_fmt) from [<80c88514>] (bvec_iter_advance+0x44/0xa8) [<80c88514>] (bvec_iter_advance) from [<80c88940>] (svc_tcp_read_msg+0x10c/0x1bc) [<80c88940>] (svc_tcp_read_msg) from [<80c895d4>] (svc_tcp_recvfrom+0x98/0x63c) [<80c895d4>] (svc_tcp_recvfrom) from [<80c97bf4>] (svc_handle_xprt+0x48c/0x4f8) [<80c97bf4>] (svc_handle_xprt) from [<80c98038>] (svc_recv+0x94/0x1e0) [<80c98038>] (svc_recv) from [<804747cc>] (nfsd+0xf0/0x168) [<804747cc>] (nfsd) from [<80148a0c>] (kthread+0x144/0x154) [<80148a0c>] (kthread) from [<80100114>] (ret_from_fork+0x14/0x20) Fixes: ca07eda33e01 ("SUNRPC: Refactor svc_recvfrom()") Cc: # 5.8+ Signed-off-by: He Zhe --- net/sunrpc/svcsock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index d5805fa1d066..ea3bc9635448 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -277,7 +277,7 @@ static ssize_t svc_tcp_read_msg(struct svc_rqst *rqstp, size_t buflen, buflen -= seek; } len = sock_recvmsg(svsk->sk_sock, &msg, MSG_DONTWAIT); - if (len > 0) + if (len > (seek & PAGE_MASK)) svc_flush_bvec(bvec, len, seek); /* If we read a full record, then assume there may be more