[PATCH v2 2/4] NFS: release per-net clients lock before calling PipeFS dentries creation
From: Stanislav Kinsbursky <hidden>
Date: 2012-02-27 15:51:21
Also in:
linux-nfs, lkml
Subsystem:
filesystems (vfs and infrastructure), nfs, sunrpc, and lockd clients, the rest · Maintainers:
Alexander Viro, Christian Brauner, Trond Myklebust, Anna Schumaker, Linus Torvalds
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 <redacted> --- 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;