From patchwork Thu Jan 5 17:13:44 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Campbell X-Patchwork-Id: 134521 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id EC2F3B6FAA for ; Fri, 6 Jan 2012 04:23:55 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932368Ab2AERXu (ORCPT ); Thu, 5 Jan 2012 12:23:50 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:41658 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757749Ab2AERXt (ORCPT ); Thu, 5 Jan 2012 12:23:49 -0500 X-Greylist: delayed 584 seconds by postgrey-1.27 at vger.kernel.org; Thu, 05 Jan 2012 12:23:48 EST X-IronPort-AV: E=Sophos;i="4.71,462,1320642000"; d="scan'208";a="176424874" Received: from ftlpmailmx02.citrite.net ([10.13.107.66]) by FTLPIPO02.CITRIX.COM with ESMTP/TLS/RC4-MD5; 05 Jan 2012 12:14:03 -0500 Received: from smtp01.ad.xensource.com (10.219.128.104) by smtprelay.citrix.com (10.13.107.66) with Microsoft SMTP Server id 8.3.213.0; Thu, 5 Jan 2012 12:14:03 -0500 Received: from cosworth.uk.xensource.com (cosworth.uk.xensource.com [10.80.16.52]) by smtp01.ad.xensource.com (8.13.1/8.13.1) with ESMTP id q05HDjo9015239; Thu, 5 Jan 2012 09:14:00 -0800 From: Ian Campbell To: netdev@vger.kernel.org CC: David Miller , Eric Dumazet , Ian Campbell , Neil Brown , "J. Bruce Fields" , linux-nfs@vger.kernel.org Subject: [PATCH 6/6] sunrpc: use SKB fragment destructors to delay completion until page is released by network stack. Date: Thu, 5 Jan 2012 17:13:44 +0000 Message-ID: <1325783624-14601-6-git-send-email-ian.campbell@citrix.com> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1325783399.25206.413.camel@zakaz.uk.xensource.com> References: <1325783399.25206.413.camel@zakaz.uk.xensource.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This prevents an issue where an ACK is delayed, a retransmit is queued (either at the RPC or TCP level) and the ACK arrives before the retransmission hits the wire. If this happens to an NFS WRITE RPC then the write() system call completes and the userspace process can continue, potentially modifying data referenced by the retransmission before the retransmission occurs. Signed-off-by: Ian Campbell Acked-by: Trond Myklebust Cc: "David S. Miller" Cc: Neil Brown Cc: "J. Bruce Fields" Cc: linux-nfs@vger.kernel.org Cc: netdev@vger.kernel.org --- include/linux/sunrpc/xdr.h | 2 ++ include/linux/sunrpc/xprt.h | 5 ++++- net/sunrpc/clnt.c | 27 ++++++++++++++++++++++----- net/sunrpc/svcsock.c | 3 ++- net/sunrpc/xprt.c | 13 +++++++++++++ net/sunrpc/xprtsock.c | 3 ++- 6 files changed, 45 insertions(+), 8 deletions(-) diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h index a20970e..172f81e 100644 --- a/include/linux/sunrpc/xdr.h +++ b/include/linux/sunrpc/xdr.h @@ -16,6 +16,7 @@ #include #include #include +#include /* * Buffer adjustment @@ -57,6 +58,7 @@ struct xdr_buf { tail[1]; /* Appended after page data */ struct page ** pages; /* Array of contiguous pages */ + struct skb_frag_destructor *destructor; unsigned int page_base, /* Start of page data */ page_len, /* Length of page data */ flags; /* Flags for data disposition */ diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h index 15518a1..75131eb 100644 --- a/include/linux/sunrpc/xprt.h +++ b/include/linux/sunrpc/xprt.h @@ -92,7 +92,10 @@ struct rpc_rqst { /* A cookie used to track the state of the transport connection */ - + struct skb_frag_destructor destructor; /* SKB paged fragment + * destructor for + * transmitted pages*/ + /* * Partial send handling */ diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index f0268ea..06f363f 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -61,6 +61,7 @@ static void call_reserve(struct rpc_task *task); static void call_reserveresult(struct rpc_task *task); static void call_allocate(struct rpc_task *task); static void call_decode(struct rpc_task *task); +static void call_complete(struct rpc_task *task); static void call_bind(struct rpc_task *task); static void call_bind_status(struct rpc_task *task); static void call_transmit(struct rpc_task *task); @@ -1115,6 +1116,8 @@ rpc_xdr_encode(struct rpc_task *task) (char *)req->rq_buffer + req->rq_callsize, req->rq_rcvsize); + req->rq_snd_buf.destructor = &req->destructor; + p = rpc_encode_header(task); if (p == NULL) { printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n"); @@ -1278,6 +1281,7 @@ call_connect_status(struct rpc_task *task) static void call_transmit(struct rpc_task *task) { + struct rpc_rqst *req = task->tk_rqstp; dprint_status(task); task->tk_action = call_status; @@ -1311,8 +1315,8 @@ call_transmit(struct rpc_task *task) call_transmit_status(task); if (rpc_reply_expected(task)) return; - task->tk_action = rpc_exit_task; - rpc_wake_up_queued_task(&task->tk_xprt->pending, task); + task->tk_action = call_complete; + skb_frag_destructor_unref(&req->destructor); } /* @@ -1385,7 +1389,8 @@ call_bc_transmit(struct rpc_task *task) return; } - task->tk_action = rpc_exit_task; + task->tk_action = call_complete; + skb_frag_destructor_unref(&req->destructor); if (task->tk_status < 0) { printk(KERN_NOTICE "RPC: Could not send backchannel reply " "error: %d\n", task->tk_status); @@ -1425,7 +1430,6 @@ call_bc_transmit(struct rpc_task *task) "error: %d\n", task->tk_status); break; } - rpc_wake_up_queued_task(&req->rq_xprt->pending, task); } #endif /* CONFIG_SUNRPC_BACKCHANNEL */ @@ -1591,12 +1595,14 @@ call_decode(struct rpc_task *task) return; } - task->tk_action = rpc_exit_task; + task->tk_action = call_complete; if (decode) { task->tk_status = rpcauth_unwrap_resp(task, decode, req, p, task->tk_msg.rpc_resp); } + rpc_sleep_on(&req->rq_xprt->pending, task, NULL); + skb_frag_destructor_unref(&req->destructor); dprintk("RPC: %5u call_decode result %d\n", task->tk_pid, task->tk_status); return; @@ -1611,6 +1617,17 @@ out_retry: } } +/* + * 8. Wait for pages to be released by the network stack. + */ +static void +call_complete(struct rpc_task *task) +{ + dprintk("RPC: %5u call_complete result %d\n", + task->tk_pid, task->tk_status); + task->tk_action = rpc_exit_task; +} + static __be32 * rpc_encode_header(struct rpc_task *task) { diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 0e6b919..aa7f108 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -198,7 +198,8 @@ int svc_send_common(struct socket *sock, struct xdr_buf *xdr, while (pglen > 0) { if (slen == size) flags = 0; - result = kernel_sendpage(sock, *ppage, NULL, base, size, flags); + result = kernel_sendpage(sock, *ppage, xdr->destructor, + base, size, flags); if (result > 0) len += result; if (result != size) diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index c64c0ef..5f28bc7 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -1101,6 +1101,16 @@ static inline void xprt_init_xid(struct rpc_xprt *xprt) xprt->xid = net_random(); } +static int xprt_complete_skb_pages(void *calldata) +{ + struct rpc_task *task = calldata; + struct rpc_rqst *req = task->tk_rqstp; + + dprintk("RPC: %5u completing skb pages\n", task->tk_pid); + rpc_wake_up_queued_task(&req->rq_xprt->pending, task); + return 0; +} + static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt) { struct rpc_rqst *req = task->tk_rqstp; @@ -1113,6 +1123,9 @@ static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt) req->rq_xid = xprt_alloc_xid(xprt); req->rq_release_snd_buf = NULL; xprt_reset_majortimeo(req); + atomic_set(&req->destructor.ref, 1); + req->destructor.destroy = &xprt_complete_skb_pages; + req->destructor.data = task; dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid, req, ntohl(req->rq_xid)); } diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 38b2fec..5406977 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -408,7 +408,8 @@ static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned i remainder -= len; if (remainder != 0 || more) flags |= MSG_MORE; - err = sock->ops->sendpage(sock, *ppage, NULL, base, len, flags); + err = sock->ops->sendpage(sock, *ppage, xdr->destructor, + base, len, flags); if (remainder == 0 || err != len) break; sent += err;