SUNRPC: Add a helper to allow sharing of rpc_pipefs directory objects
Add support for looking up existing objects and creating new ones if there
is no match.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index a35b2f4..f94567b 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -982,6 +982,41 @@
}
EXPORT_SYMBOL_GPL(rpc_remove_pipe_dir_object);
+/**
+ * rpc_find_or_alloc_pipe_dir_object
+ * @net: pointer to struct net
+ * @pdh: pointer to struct rpc_pipe_dir_head
+ * @match: match struct rpc_pipe_dir_object to data
+ * @alloc: allocate a new struct rpc_pipe_dir_object
+ * @data: user defined data for match() and alloc()
+ *
+ */
+struct rpc_pipe_dir_object *
+rpc_find_or_alloc_pipe_dir_object(struct net *net,
+ struct rpc_pipe_dir_head *pdh,
+ int (*match)(struct rpc_pipe_dir_object *, void *),
+ struct rpc_pipe_dir_object *(*alloc)(void *),
+ void *data)
+{
+ struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+ struct rpc_pipe_dir_object *pdo;
+
+ mutex_lock(&sn->pipefs_sb_lock);
+ list_for_each_entry(pdo, &pdh->pdh_entries, pdo_head) {
+ if (!match(pdo, data))
+ continue;
+ goto out;
+ }
+ pdo = alloc(data);
+ if (!pdo)
+ goto out;
+ rpc_add_pipe_dir_object_locked(net, pdh, pdo);
+out:
+ mutex_unlock(&sn->pipefs_sb_lock);
+ return pdo;
+}
+EXPORT_SYMBOL_GPL(rpc_find_or_alloc_pipe_dir_object);
+
static void
rpc_create_pipe_dir_objects(struct rpc_pipe_dir_head *pdh)
{