From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: [PATCH 003 of 4] knfsd: Fix recently introduced problem with shutting down a busy NFS server. Date: Tue, 6 Mar 2007 13:15:15 +1100 Message-ID: <1070306021515.26922@suse.de> References: <20070306131103.26638.patches@notabene> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: nfs@lists.sourceforge.net, linux-kernel@vger.kernel.org To: Andrew Morton Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1HOPEB-0006hc-Ti for nfs@lists.sourceforge.net; Mon, 05 Mar 2007 18:16:36 -0800 Received: from mail.suse.de ([195.135.220.2] helo=mx1.suse.de) by mail.sourceforge.net with esmtp (Exim 4.44) id 1HOPEB-0005W1-E1 for nfs@lists.sourceforge.net; Mon, 05 Mar 2007 18:16:38 -0800 List-Id: "Discussion of NFS under Linux development, interoperability, and testing." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfs-bounces@lists.sourceforge.net Errors-To: nfs-bounces@lists.sourceforge.net When the last thread of nfsd exits, it shuts down all related sockets. It currently uses svc_close_socket to do this, but that only is immediately effective if the socket is not SK_BUSY. If the socket is busy - i.e. if a request has arrived that has not yet been processes - svc_close_socket is not effective and the shutdown process spins. So create a new svc_force_close_socket which removes the SK_BUSY flag is set and then calls svc_close_socket. Also change some open-codes loops in svc_destroy to use list_for_each_entry_safe. Signed-off-by: Neil Brown ### Diffstat output ./include/linux/sunrpc/svcsock.h | 2 +- ./net/sunrpc/svc.c | 21 +++++++++------------ ./net/sunrpc/svcsock.c | 16 +++++++++++++++- 3 files changed, 25 insertions(+), 14 deletions(-) diff .prev/include/linux/sunrpc/svcsock.h ./include/linux/sunrpc/svcsock.h --- .prev/include/linux/sunrpc/svcsock.h 2007-03-06 12:19:18.000000000 +1100 +++ ./include/linux/sunrpc/svcsock.h 2007-03-06 12:19:23.000000000 +1100 @@ -66,7 +66,7 @@ struct svc_sock { * Function prototypes. */ int svc_makesock(struct svc_serv *, int, unsigned short, int flags); -void svc_close_socket(struct svc_sock *); +void svc_force_close_socket(struct svc_sock *); int svc_recv(struct svc_rqst *, long); int svc_send(struct svc_rqst *); void svc_drop(struct svc_rqst *); diff .prev/net/sunrpc/svc.c ./net/sunrpc/svc.c --- .prev/net/sunrpc/svc.c 2007-03-06 12:02:18.000000000 +1100 +++ ./net/sunrpc/svc.c 2007-03-06 12:27:12.000000000 +1100 @@ -367,6 +367,7 @@ void svc_destroy(struct svc_serv *serv) { struct svc_sock *svsk; + struct svc_sock *tmp; dprintk("svc: svc_destroy(%s, %d)\n", serv->sv_program->pg_name, @@ -382,21 +383,17 @@ svc_destroy(struct svc_serv *serv) del_timer_sync(&serv->sv_temptimer); - while (!list_empty(&serv->sv_tempsocks)) { - svsk = list_entry(serv->sv_tempsocks.next, - struct svc_sock, - sk_list); - svc_close_socket(svsk); - } + list_for_each_entry_safe(svsk, tmp, &serv->sv_tempsocks, sk_list) + svc_force_close_socket(svsk); + if (serv->sv_shutdown) serv->sv_shutdown(serv); - while (!list_empty(&serv->sv_permsocks)) { - svsk = list_entry(serv->sv_permsocks.next, - struct svc_sock, - sk_list); - svc_close_socket(svsk); - } + list_for_each_entry_safe(svsk, tmp, &serv->sv_permsocks, sk_list) + svc_force_close_socket(svsk); + + BUG_ON(!list_empty(&serv->sv_permsocks)); + BUG_ON(!list_empty(&serv->sv_tempsocks)); cache_clean_deferred(serv); diff .prev/net/sunrpc/svcsock.c ./net/sunrpc/svcsock.c --- .prev/net/sunrpc/svcsock.c 2007-03-06 11:12:40.000000000 +1100 +++ ./net/sunrpc/svcsock.c 2007-03-06 12:36:20.000000000 +1100 @@ -82,6 +82,7 @@ static void svc_delete_socket(struct sv static void svc_udp_data_ready(struct sock *, int); static int svc_udp_recvfrom(struct svc_rqst *); static int svc_udp_sendto(struct svc_rqst *); +static void svc_close_socket(struct svc_sock *svsk); static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk); static int svc_deferred_recv(struct svc_rqst *rqstp); @@ -1787,7 +1788,7 @@ svc_delete_socket(struct svc_sock *svsk) spin_unlock_bh(&serv->sv_lock); } -void svc_close_socket(struct svc_sock *svsk) +static void svc_close_socket(struct svc_sock *svsk) { set_bit(SK_CLOSE, &svsk->sk_flags); if (test_and_set_bit(SK_BUSY, &svsk->sk_flags)) @@ -1800,6 +1801,19 @@ void svc_close_socket(struct svc_sock *s svc_sock_put(svsk); } +void svc_force_close_socket(struct svc_sock *svsk) +{ + set_bit(SK_CLOSE, &svsk->sk_flags); + if (test_bit(SK_BUSY, &svsk->sk_flags)) { + /* Waiting to be processed, but no threads left, + * So just remove it from the waiting list + */ + list_del_init(&svsk->sk_ready); + clear_bit(SK_BUSY, &svsk->sk_flags); + } + svc_close_socket(svsk); +} + /** * svc_makesock - Make a socket for nfsd and lockd * @serv: RPC server structure ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965748AbXCFCQt (ORCPT ); Mon, 5 Mar 2007 21:16:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965747AbXCFCQs (ORCPT ); Mon, 5 Mar 2007 21:16:48 -0500 Received: from ns.suse.de ([195.135.220.2]:47926 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933861AbXCFCQb (ORCPT ); Mon, 5 Mar 2007 21:16:31 -0500 From: NeilBrown To: Andrew Morton Date: Tue, 6 Mar 2007 13:15:15 +1100 Message-Id: <1070306021515.26922@suse.de> X-face: [Gw_3E*Gng}4rRrKRYotwlE?.2|**#s9D Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org When the last thread of nfsd exits, it shuts down all related sockets. It currently uses svc_close_socket to do this, but that only is immediately effective if the socket is not SK_BUSY. If the socket is busy - i.e. if a request has arrived that has not yet been processes - svc_close_socket is not effective and the shutdown process spins. So create a new svc_force_close_socket which removes the SK_BUSY flag is set and then calls svc_close_socket. Also change some open-codes loops in svc_destroy to use list_for_each_entry_safe. Signed-off-by: Neil Brown ### Diffstat output ./include/linux/sunrpc/svcsock.h | 2 +- ./net/sunrpc/svc.c | 21 +++++++++------------ ./net/sunrpc/svcsock.c | 16 +++++++++++++++- 3 files changed, 25 insertions(+), 14 deletions(-) diff .prev/include/linux/sunrpc/svcsock.h ./include/linux/sunrpc/svcsock.h --- .prev/include/linux/sunrpc/svcsock.h 2007-03-06 12:19:18.000000000 +1100 +++ ./include/linux/sunrpc/svcsock.h 2007-03-06 12:19:23.000000000 +1100 @@ -66,7 +66,7 @@ struct svc_sock { * Function prototypes. */ int svc_makesock(struct svc_serv *, int, unsigned short, int flags); -void svc_close_socket(struct svc_sock *); +void svc_force_close_socket(struct svc_sock *); int svc_recv(struct svc_rqst *, long); int svc_send(struct svc_rqst *); void svc_drop(struct svc_rqst *); diff .prev/net/sunrpc/svc.c ./net/sunrpc/svc.c --- .prev/net/sunrpc/svc.c 2007-03-06 12:02:18.000000000 +1100 +++ ./net/sunrpc/svc.c 2007-03-06 12:27:12.000000000 +1100 @@ -367,6 +367,7 @@ void svc_destroy(struct svc_serv *serv) { struct svc_sock *svsk; + struct svc_sock *tmp; dprintk("svc: svc_destroy(%s, %d)\n", serv->sv_program->pg_name, @@ -382,21 +383,17 @@ svc_destroy(struct svc_serv *serv) del_timer_sync(&serv->sv_temptimer); - while (!list_empty(&serv->sv_tempsocks)) { - svsk = list_entry(serv->sv_tempsocks.next, - struct svc_sock, - sk_list); - svc_close_socket(svsk); - } + list_for_each_entry_safe(svsk, tmp, &serv->sv_tempsocks, sk_list) + svc_force_close_socket(svsk); + if (serv->sv_shutdown) serv->sv_shutdown(serv); - while (!list_empty(&serv->sv_permsocks)) { - svsk = list_entry(serv->sv_permsocks.next, - struct svc_sock, - sk_list); - svc_close_socket(svsk); - } + list_for_each_entry_safe(svsk, tmp, &serv->sv_permsocks, sk_list) + svc_force_close_socket(svsk); + + BUG_ON(!list_empty(&serv->sv_permsocks)); + BUG_ON(!list_empty(&serv->sv_tempsocks)); cache_clean_deferred(serv); diff .prev/net/sunrpc/svcsock.c ./net/sunrpc/svcsock.c --- .prev/net/sunrpc/svcsock.c 2007-03-06 11:12:40.000000000 +1100 +++ ./net/sunrpc/svcsock.c 2007-03-06 12:36:20.000000000 +1100 @@ -82,6 +82,7 @@ static void svc_delete_socket(struct sv static void svc_udp_data_ready(struct sock *, int); static int svc_udp_recvfrom(struct svc_rqst *); static int svc_udp_sendto(struct svc_rqst *); +static void svc_close_socket(struct svc_sock *svsk); static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk); static int svc_deferred_recv(struct svc_rqst *rqstp); @@ -1787,7 +1788,7 @@ svc_delete_socket(struct svc_sock *svsk) spin_unlock_bh(&serv->sv_lock); } -void svc_close_socket(struct svc_sock *svsk) +static void svc_close_socket(struct svc_sock *svsk) { set_bit(SK_CLOSE, &svsk->sk_flags); if (test_and_set_bit(SK_BUSY, &svsk->sk_flags)) @@ -1800,6 +1801,19 @@ void svc_close_socket(struct svc_sock *s svc_sock_put(svsk); } +void svc_force_close_socket(struct svc_sock *svsk) +{ + set_bit(SK_CLOSE, &svsk->sk_flags); + if (test_bit(SK_BUSY, &svsk->sk_flags)) { + /* Waiting to be processed, but no threads left, + * So just remove it from the waiting list + */ + list_del_init(&svsk->sk_ready); + clear_bit(SK_BUSY, &svsk->sk_flags); + } + svc_close_socket(svsk); +} + /** * svc_makesock - Make a socket for nfsd and lockd * @serv: RPC server structure