From da3b462296e421e8f54b54b7d2706488661c36e2 Mon Sep 17 00:00:00 2001 From: Stanislav Kinsbursky Date: Mon, 27 Feb 2012 22:05:29 +0400 Subject: [PATCH] SUNRPC: release per-net clients lock before calling PipeFS dentries creation v3: 1) Lookup for client is performed from the beginning of the list on each PipeFS event handling operation. 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 Signed-off-by: Trond Myklebust --- net/sunrpc/clnt.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index bb7ed2f3aee6..25c3da53fb69 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -204,21 +204,37 @@ static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event, return err; } +static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event) +{ + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + struct rpc_clnt *clnt; + + spin_lock(&sn->rpc_client_lock); + list_for_each_entry(clnt, &sn->all_clients, cl_clients) { + if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) || + ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry)) + continue; + atomic_inc(&clnt->cl_count); + spin_unlock(&sn->rpc_client_lock); + return clnt; + } + spin_unlock(&sn->rpc_client_lock); + return NULL; +} + static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event, void *ptr) { struct super_block *sb = ptr; struct rpc_clnt *clnt; int error = 0; - struct sunrpc_net *sn = net_generic(sb->s_fs_info, sunrpc_net_id); - spin_lock(&sn->rpc_client_lock); - list_for_each_entry(clnt, &sn->all_clients, cl_clients) { + while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) { error = __rpc_pipefs_event(clnt, event, sb); + rpc_release_client(clnt); if (error) break; } - spin_unlock(&sn->rpc_client_lock); return error; } -- 2.34.1