NFSv4: Fix a race in the net namespace mount notification

Since the struct nfs_client gets added to the global nfs_client_list
before it is initialised, it is possible that rpc_pipefs_event can
end up trying to create idmapper entries on such a thing.

The solution is to have the mount notification wait for the
initialisation of each nfs_client to complete, and then to
skip any entries for which the it failed.

Reported-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
This commit is contained in:
Trond Myklebust
2012-05-23 13:24:36 -04:00
parent 7b38c3682c
commit 4697bd5e94
3 changed files with 29 additions and 3 deletions

View File

@@ -530,9 +530,24 @@ static struct nfs_client *nfs_get_client_for_event(struct net *net, int event)
struct nfs_net *nn = net_generic(net, nfs_net_id);
struct dentry *cl_dentry;
struct nfs_client *clp;
int err;
restart:
spin_lock(&nn->nfs_client_lock);
list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
/* Wait for initialisation to finish */
if (clp->cl_cons_state == NFS_CS_INITING) {
atomic_inc(&clp->cl_count);
spin_unlock(&nn->nfs_client_lock);
err = nfs_wait_client_init_complete(clp);
nfs_put_client(clp);
if (err)
return NULL;
goto restart;
}
/* Skip nfs_clients that failed to initialise */
if (clp->cl_cons_state < 0)
continue;
if (clp->rpc_ops != &nfs_v4_clientops)
continue;
cl_dentry = clp->cl_idmap->idmap_pipe->dentry;