Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756823Ab3CDDoR (ORCPT ); Sun, 3 Mar 2013 22:44:17 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33005 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756673Ab3CDDoL (ORCPT ); Sun, 3 Mar 2013 22:44:11 -0500 Message-Id: <20130304033713.869066939@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 04 Mar 2013 03:38:11 +0000 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, "J. Bruce Fields" , Jason Tibbitts , =?ISO-8859-15?q?Pawe=C5=82=20Sikora?= Subject: [ 064/153] svcrpc: make svc_age_temp_xprts enqueue under sv_lock In-Reply-To: <20130304033707.648729212@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:a11:96ff:fec6:70c4 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 Content-Length: 2357 Lines: 71 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: "J. Bruce Fields" commit e75bafbff2270993926abcc31358361db74a9bc2 upstream. svc_age_temp_xprts expires xprts in a two-step process: first it takes the sv_lock and moves the xprts to expire off their server-wide list (sv_tempsocks or sv_permsocks) to a local list. Then it drops the sv_lock and enqueues and puts each one. I see no reason for this: svc_xprt_enqueue() will take sp_lock, but the sv_lock and sp_lock are not otherwise nested anywhere (and documentation at the top of this file claims it's correct to nest these with sp_lock inside.) Tested-by: Jason Tibbitts Tested-by: Paweł Sikora Signed-off-by: J. Bruce Fields Signed-off-by: Ben Hutchings --- net/sunrpc/svc_xprt.c | 15 ++------------- 1 file changed, 2 insertions(+), 13 deletions(-) --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -816,7 +816,6 @@ static void svc_age_temp_xprts(unsigned struct svc_serv *serv = (struct svc_serv *)closure; struct svc_xprt *xprt; struct list_head *le, *next; - LIST_HEAD(to_be_aged); dprintk("svc_age_temp_xprts\n"); @@ -837,25 +836,15 @@ static void svc_age_temp_xprts(unsigned if (atomic_read(&xprt->xpt_ref.refcount) > 1 || test_bit(XPT_BUSY, &xprt->xpt_flags)) continue; - svc_xprt_get(xprt); - list_move(le, &to_be_aged); + list_del_init(le); set_bit(XPT_CLOSE, &xprt->xpt_flags); set_bit(XPT_DETACHED, &xprt->xpt_flags); - } - spin_unlock_bh(&serv->sv_lock); - - while (!list_empty(&to_be_aged)) { - le = to_be_aged.next; - /* fiddling the xpt_list node is safe 'cos we're XPT_DETACHED */ - list_del_init(le); - xprt = list_entry(le, struct svc_xprt, xpt_list); - dprintk("queuing xprt %p for closing\n", xprt); /* a thread will dequeue and close it soon */ svc_xprt_enqueue(xprt); - svc_xprt_put(xprt); } + spin_unlock_bh(&serv->sv_lock); mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); } -- 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/