Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966539AbaLLGzn (ORCPT ); Fri, 12 Dec 2014 01:55:43 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51760 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758677AbaLLGQy (ORCPT ); Fri, 12 Dec 2014 01:16:54 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "J. Bruce Fields" , "Jeff Layton" , "Trond Myklebust" Date: Fri, 12 Dec 2014 06:14:25 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 141/164] SUNRPC: Fix locking around callback channel reply receive In-Reply-To: X-SA-Exim-Connect-IP: 2001:470:1f08:1539:c97:8151:cc89:c28d X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.65-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Trond Myklebust commit 093a1468b6edb0e568be7311b8d2228d205702db upstream. Both xprt_lookup_rqst() and xprt_complete_rqst() require that you take the transport lock in order to avoid races with xprt_transmit(). Signed-off-by: Trond Myklebust Reviewed-by: Jeff Layton Signed-off-by: J. Bruce Fields [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- net/sunrpc/svcsock.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -1054,17 +1054,12 @@ static int receive_cb_reply(struct svc_s xid = *p++; calldir = *p; - if (bc_xprt) - req = xprt_lookup_rqst(bc_xprt, xid); - - if (!req) { - printk(KERN_NOTICE - "%s: Got unrecognized reply: " - "calldir 0x%x xpt_bc_xprt %p xid %08x\n", - __func__, ntohl(calldir), - bc_xprt, ntohl(xid)); + if (!bc_xprt) return -EAGAIN; - } + spin_lock_bh(&bc_xprt->transport_lock); + req = xprt_lookup_rqst(bc_xprt, xid); + if (!req) + goto unlock_notfound; memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(struct xdr_buf)); /* @@ -1075,11 +1070,21 @@ static int receive_cb_reply(struct svc_s dst = &req->rq_private_buf.head[0]; src = &rqstp->rq_arg.head[0]; if (dst->iov_len < src->iov_len) - return -EAGAIN; /* whatever; just giving up. */ + goto unlock_eagain; /* whatever; just giving up. */ memcpy(dst->iov_base, src->iov_base, src->iov_len); xprt_complete_rqst(req->rq_task, svsk->sk_reclen); rqstp->rq_arg.len = 0; + spin_unlock_bh(&bc_xprt->transport_lock); return 0; +unlock_notfound: + printk(KERN_NOTICE + "%s: Got unrecognized reply: " + "calldir 0x%x xpt_bc_xprt %p xid %08x\n", + __func__, ntohl(calldir), + bc_xprt, ntohl(xid)); +unlock_eagain: + spin_unlock_bh(&bc_xprt->transport_lock); + return -EAGAIN; } static int copy_pages_to_kvecs(struct kvec *vec, struct page **pages, int len) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/