Commit fca5238e authored by Chuck Lever's avatar Chuck Lever Committed by Trond Myklebust
Browse files

NFS: Allow walking nfs_client.cl_superblocks list outside client.c 



We're about to move some fields from struct nfs_client to struct
nfs_server.  There is a many-to-one relationship between nfs_servers
and nfs_clients.  After these fields are moved to the nfs_server
struct, to visit all of the data in these fields that is owned by one
nfs_client, code will need to visit each nfs_server on the
cl_superblocks list for that nfs_client.

To serialize changes to the cl_superblocks list during these little
expeditions, protect the list with RCU.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent f7e8917a

fs/nfs/client.c

+25 −19
Original line number Diff line number Diff line
@@ -1003,6 +1003,27 @@ static void nfs_server_copy_userdata(struct nfs_server *target, struct nfs_serve 
	target->options = source->options;

}



static void nfs_server_insert_lists(struct nfs_server *server)

{

	struct nfs_client *clp = server->nfs_client;



	spin_lock(&nfs_client_lock);

	list_add_tail_rcu(&server->client_link, &clp->cl_superblocks);

	list_add_tail(&server->master_link, &nfs_volume_list);

	spin_unlock(&nfs_client_lock);



}



static void nfs_server_remove_lists(struct nfs_server *server)

{

	spin_lock(&nfs_client_lock);

	list_del_rcu(&server->client_link);

	list_del(&server->master_link);

	spin_unlock(&nfs_client_lock);



	synchronize_rcu();

}



/*

 * Allocate and initialise a server record

 */
@@ -1046,11 +1067,8 @@ void nfs_free_server(struct nfs_server *server) 
{

	dprintk("--> nfs_free_server()\n");



	nfs_server_remove_lists(server);

	unset_pnfs_layoutdriver(server);

	spin_lock(&nfs_client_lock);

	list_del(&server->client_link);

	list_del(&server->master_link);

	spin_unlock(&nfs_client_lock);



	if (server->destroy != NULL)

		server->destroy(server);
@@ -1125,11 +1143,7 @@ struct nfs_server *nfs_create_server(const struct nfs_parsed_mount_data *data, 
		(unsigned long long) server->fsid.major,

		(unsigned long long) server->fsid.minor);



	spin_lock(&nfs_client_lock);

	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);

	list_add_tail(&server->master_link, &nfs_volume_list);

	spin_unlock(&nfs_client_lock);



	nfs_server_insert_lists(server);

	server->mount_time = jiffies;

	nfs_free_fattr(fattr);

	return server;
@@ -1454,11 +1468,7 @@ static int nfs4_server_common_setup(struct nfs_server *server, 
	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)

		server->namelen = NFS4_MAXNAMLEN;



	spin_lock(&nfs_client_lock);

	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);

	list_add_tail(&server->master_link, &nfs_volume_list);

	spin_unlock(&nfs_client_lock);



	nfs_server_insert_lists(server);

	server->mount_time = jiffies;

out:

	nfs_free_fattr(fattr);
@@ -1663,11 +1673,7 @@ struct nfs_server *nfs_clone_server(struct nfs_server *source, 
	if (error < 0)

		goto out_free_server;



	spin_lock(&nfs_client_lock);

	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);

	list_add_tail(&server->master_link, &nfs_volume_list);

	spin_unlock(&nfs_client_lock);



	nfs_server_insert_lists(server);

	server->mount_time = jiffies;



	nfs_free_fattr(fattr_fsinfo);

fs/nfs/nfs4renewd.c

+7 −2
Original line number Diff line number Diff line
@@ -63,9 +63,14 @@ nfs4_renew_state(struct work_struct *work) 


	ops = clp->cl_mvops->state_renewal_ops;

	dprintk("%s: start\n", __func__);

	/* Are there any active superblocks? */

	if (list_empty(&clp->cl_superblocks))



	rcu_read_lock();

	if (list_empty(&clp->cl_superblocks)) {

		rcu_read_unlock();

		goto out;

	}

	rcu_read_unlock();



	spin_lock(&clp->cl_lock);

	lease = clp->cl_lease_time;

	last = clp->cl_last_renewal;

CRA Git | Maintained and supported by SUSTech CRA and CCSE