From: "J. Bruce Fields" Subject: [PATCH 04/12] lockd: unmonitor only when last host goes away Date: Wed, 5 Nov 2008 15:06:43 -0500 Message-ID: <1225915611-2401-4-git-send-email-bfields@citi.umich.edu> References: <20081105172351.7330.50739.stgit@ingres.1015granger.net> <1225915611-2401-1-git-send-email-bfields@citi.umich.edu> <1225915611-2401-2-git-send-email-bfields@citi.umich.edu> <1225915611-2401-3-git-send-email-bfields@citi.umich.edu> Cc: linux-nfs@vger.kernel.org, "J. Bruce Fields" To: Chuck Lever Return-path: Received: from mail.fieldses.org ([66.93.2.214]:39489 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757500AbYKEUGz (ORCPT ); Wed, 5 Nov 2008 15:06:55 -0500 In-Reply-To: <1225915611-2401-3-git-send-email-bfields@citi.umich.edu> Sender: linux-nfs-owner@vger.kernel.org List-ID: The sm_sticky logic seems racy; instead just unmonitor before destruction of handle. XXX: how to test? Signed-off-by: J. Bruce Fields --- fs/lockd/host.c | 24 ++++++++++++++++++++---- fs/lockd/mon.c | 15 +-------------- fs/lockd/svcsubs.c | 6 ------ include/linux/lockd/lockd.h | 3 +-- 4 files changed, 22 insertions(+), 26 deletions(-) diff --git a/fs/lockd/host.c b/fs/lockd/host.c index e9069c2..1a1adb9 100644 --- a/fs/lockd/host.c +++ b/fs/lockd/host.c @@ -683,6 +683,10 @@ found: return nsm; } + +/* XXX: */ +int nsm_mon_unmon(struct nsm_handle *, u32, struct nsm_res *); + /* * Release an NSM handle */ @@ -691,9 +695,21 @@ nsm_release(struct nsm_handle *nsm) { if (!nsm) return; - if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) { - list_del(&nsm->sm_link); - spin_unlock(&nsm_lock); - kfree(nsm); + if (!atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) + return; + list_del(&nsm->sm_link); + spin_unlock(&nsm_lock); + if (nsm->sm_monitored) { + struct nsm_res res; + int status; + + dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name); + status = nsm_mon_unmon(nsm, SM_UNMON, &res); + if (status < 0) + printk(KERN_NOTICE "lockd: cannot unmonitor %s\n", + nsm->sm_name); + else + nsm->sm_monitored = 0; } + kfree(nsm); } diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c index 480f197..8cc0e97 100644 --- a/fs/lockd/mon.c +++ b/fs/lockd/mon.c @@ -32,7 +32,7 @@ int nsm_local_state; /* * Common procedure for SM_MON/SM_UNMON calls */ -static int +int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res) { struct rpc_clnt *clnt; @@ -100,24 +100,11 @@ nsm_monitor(struct nlm_host *host) void nsm_unmonitor(struct nlm_host *host) { struct nsm_handle *nsm = host->h_nsmhandle; - struct nsm_res res; - int status; if (nsm == NULL) return; host->h_nsmhandle = NULL; - if (atomic_read(&nsm->sm_count) == 1 - && nsm->sm_monitored && !nsm->sm_sticky) { - dprintk("lockd: nsm_unmonitor(%s)\n", host->h_name); - - status = nsm_mon_unmon(nsm, SM_UNMON, &res); - if (status < 0) - printk(KERN_NOTICE "lockd: cannot unmonitor %s\n", - host->h_name); - else - nsm->sm_monitored = 0; - } nsm_release(nsm); } diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c index 9c186f0..0296904 100644 --- a/fs/lockd/svcsubs.c +++ b/fs/lockd/svcsubs.c @@ -336,12 +336,6 @@ nlmsvc_is_client(void *data, struct nlm_host *dummy) struct nlm_host *host = data; BUG_ON(!host->h_server); - /* we are destroying locks even though the client - * hasn't asked us too, so don't unmonitor the - * client - */ - if (host->h_nsmhandle) - host->h_nsmhandle->sm_sticky = 1; return 1; } diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h index b56d5aa..e1c2690 100644 --- a/include/linux/lockd/lockd.h +++ b/include/linux/lockd/lockd.h @@ -75,8 +75,7 @@ struct nsm_handle { char * sm_name; struct sockaddr_storage sm_addr; size_t sm_addrlen; - unsigned int sm_monitored : 1, - sm_sticky : 1; /* don't unmonitor */ + unsigned int sm_monitored : 1; char sm_addrbuf[48]; /* address eyecatcher */ }; -- 1.5.5.rc1