From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stanislav Kinsbursky Subject: [PATCH v2 2/4] NFS: release per-net clients lock before calling PipeFS dentries creation Date: Mon, 27 Feb 2012 19:51:04 +0400 Message-ID: <20120227155103.7941.17006.stgit@localhost6.localdomain6> References: <20120227154713.7941.17963.stgit@localhost6.localdomain6> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: linux-nfs@vger.kernel.org, xemul@parallels.com, neilb@suse.de, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, jbottomley@parallels.com, bfields@fieldses.org, davem@davemloft.net, devel@openvz.org To: Trond.Myklebust@netapp.com Return-path: In-Reply-To: <20120227154713.7941.17963.stgit@localhost6.localdomain6> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Lockdep is sad otherwise, because inode mutex is taken on PipeFS dentry creation, which can be called on mount notification, where this per-net client lock is taken on clients list walk. Signed-off-by: Stanislav Kinsbursky --- fs/nfs/client.c | 2 +- fs/nfs/idmap.c | 8 ++++++-- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/nfs/client.c b/fs/nfs/client.c index 8563585..6aeb6b3 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -538,7 +538,7 @@ nfs_get_client(const struct nfs_client_initdata *cl_init, /* install a new client and return with it unready */ install_client: clp = new; - list_add(&clp->cl_share_link, &nn->nfs_client_list); + list_add_tail(&clp->cl_share_link, &nn->nfs_client_list); spin_unlock(&nn->nfs_client_lock); error = cl_init->rpc_ops->init_client(clp, timeparms, ip_addr, diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c index b5c6d8e..8a9e7a4 100644 --- a/fs/nfs/idmap.c +++ b/fs/nfs/idmap.c @@ -558,16 +558,20 @@ static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event, { struct super_block *sb = ptr; struct nfs_net *nn = net_generic(sb->s_fs_info, nfs_net_id); - struct nfs_client *clp; + struct nfs_client *clp, *tmp; int error = 0; spin_lock(&nn->nfs_client_lock); - list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) { + list_for_each_entry_safe(clp, tmp, &nn->nfs_client_list, cl_share_link) { if (clp->rpc_ops != &nfs_v4_clientops) continue; + atomic_inc(&clp->cl_count); + spin_unlock(&nn->nfs_client_lock); error = __rpc_pipefs_event(clp, event, sb); + nfs_put_client(clp); if (error) break; + spin_lock(&nn->nfs_client_lock); } spin_unlock(&nn->nfs_client_lock); return error;