Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx.bwstor.com.cn ([211.103.180.228]:32825 "EHLO mx.bwstor.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751004AbaBHCeT (ORCPT ); Fri, 7 Feb 2014 21:34:19 -0500 From: shaobingqing To: trond.myklebust@primarydata.com, bfields@redhat.com, davem@davemloft.net Cc: linux-nfs@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, shaobingqing Subject: [PATCH v2] SUNRPC: Allow one callback request to be received from two sk_buff Date: Sat, 8 Feb 2014 10:29:03 +0800 Message-Id: <1391826543-3102-1-git-send-email-shaobingqing@bwstor.com.cn> In-Reply-To: References: Sender: linux-nfs-owner@vger.kernel.org List-ID: In current code, there only one struct rpc_rqst is prealloced. If one callback request is received from two sk_buff, the xprt_alloc_bc_request would be execute two times with the same transport->xid. The first time xprt_alloc_bc_request will alloc one struct rpc_rqst and the TCP_RCV_COPY_DATA bit of transport->tcp_flags will not be cleared. The second time xprt_alloc_bc_request could not alloc struct rpc_rqst any more and NULL pointer will be returned, then xprt_force_disconnect occur. I think one callback request can be allowed to be received from two sk_buff. Signed-off-by: shaobingqing --- include/linux/sunrpc/xprt.h | 1 + net/sunrpc/xprt.c | 1 + net/sunrpc/xprtsock.c | 13 ++++++++++++- 3 files changed, 14 insertions(+), 1 deletions(-) diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index cec7b9b..82bfe01 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -211,6 +211,7 @@ struct rpc_xprt { * items */ struct list_head bc_pa_list; /* List of preallocated * backchannel rpc_rqst's */ + struct rpc_rqst *req_first; #endif /* CONFIG_SUNRPC_BACKCHANNEL */ struct list_head recv; diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 095363e..93ad8bc 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -1256,6 +1256,7 @@ static void xprt_init(struct rpc_xprt *xprt, struct net *net) #if defined(CONFIG_SUNRPC_BACKCHANNEL) spin_lock_init(&xprt->bc_pa_lock); INIT_LIST_HEAD(&xprt->bc_pa_list); + xprt->req_first = NULL; #endif /* CONFIG_SUNRPC_BACKCHANNEL */ xprt->last_used = jiffies; diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index ee03d35..c43dca4 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -1272,7 +1272,16 @@ static inline int xs_tcp_read_callback(struct rpc_xprt *xprt, container_of(xprt, struct sock_xprt, xprt); struct rpc_rqst *req; - req = xprt_alloc_bc_request(xprt); + if (xprt->req_first != NULL && + xprt->req_first->rq_xid == transport->tcp_xid) { + req = xprt->req_first; + } else if (xprt->req_first != NULL && + xprt->req_first->rq_xid != transport->tcp_xid) { + xprt_free_bc_request(xprt); + req = xprt_alloc_bc_request(xprt); + } else { + req = xprt_alloc_bc_request(xprt); + } if (req == NULL) { printk(KERN_WARNING "Callback slot table overflowed\n"); xprt_force_disconnect(xprt); @@ -1297,6 +1306,8 @@ static inline int xs_tcp_read_callback(struct rpc_xprt *xprt, list_add(&req->rq_bc_list, &bc_serv->sv_cb_list); spin_unlock(&bc_serv->sv_cb_lock); wake_up(&bc_serv->sv_cb_waitq); + } else { + xprt->req_first = req; } req->rq_private_buf.len = transport->tcp_copied; -- 1.7.4.2