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Commit 7b38c368 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4.1: Fix session initialisation races 



Session initialisation is not complete until the lease manager
has run. We need to ensure that both nfs4_init_session and
nfs4_init_ds_session do so, and that they check for any resulting
errors in clp->cl_cons_state.

Only after this is done, can nfs4_ds_connect check the contents
of clp->cl_exchange_flags.

Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: Andy Adamson <andros@netapp.com>
parent acdeb69d

fs/nfs/client.c

+0 −16
Original line number Diff line number Diff line
@@ -591,22 +591,6 @@ void nfs_mark_client_ready(struct nfs_client *clp, int state) 
	wake_up_all(&nfs_client_active_wq);

}



/*

 * With sessions, the client is not marked ready until after a

 * successful EXCHANGE_ID and CREATE_SESSION.

 *

 * Map errors cl_cons_state errors to EPROTONOSUPPORT to indicate

 * other versions of NFS can be tried.

 */

int nfs4_check_client_ready(struct nfs_client *clp)

{

	if (!nfs4_has_session(clp))

		return 0;

	if (clp->cl_cons_state < NFS_CS_READY)

		return -EPROTONOSUPPORT;

	return 0;

}



/*

 * Initialise the timeout values for a connection

 */

fs/nfs/internal.h

+1 −2
Original line number Diff line number Diff line
@@ -169,7 +169,6 @@ extern struct nfs_server *nfs_clone_server(struct nfs_server *, 
					   struct nfs_fattr *,

					   rpc_authflavor_t);

extern void nfs_mark_client_ready(struct nfs_client *clp, int state);

extern int nfs4_check_client_ready(struct nfs_client *clp);

extern struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp,

					     const struct sockaddr *ds_addr,

					     int ds_addrlen, int ds_proto,
@@ -234,7 +233,7 @@ extern const u32 nfs41_maxwrite_overhead; 
extern struct rpc_procinfo nfs4_procedures[];

#endif



extern int nfs4_init_ds_session(struct nfs_client *clp);

extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);



/* proc.c */

void nfs_close_context(struct nfs_open_context *ctx, int is_sync);

fs/nfs/nfs4filelayoutdev.c

+1 −22
Original line number Diff line number Diff line
@@ -203,28 +203,7 @@ nfs4_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds) 
		goto out;

	}



	if ((clp->cl_exchange_flags & EXCHGID4_FLAG_MASK_PNFS) != 0) {

		if (!is_ds_client(clp)) {

			status = -ENODEV;

			goto out_put;

		}

		ds->ds_clp = clp;

		dprintk("%s [existing] server=%s\n", __func__,

			ds->ds_remotestr);

		goto out;

	}



	/*

	 * Do not set NFS_CS_CHECK_LEASE_TIME instead set the DS lease to

	 * be equal to the MDS lease. Renewal is scheduled in create_session.

	 */

	spin_lock(&mds_srv->nfs_client->cl_lock);

	clp->cl_lease_time = mds_srv->nfs_client->cl_lease_time;

	spin_unlock(&mds_srv->nfs_client->cl_lock);

	clp->cl_last_renewal = jiffies;



	/* New nfs_client */

	status = nfs4_init_ds_session(clp);

	status = nfs4_init_ds_session(clp, mds_srv->nfs_client->cl_lease_time);

	if (status)

		goto out_put;

fs/nfs/nfs4proc.c

+52 −27
Original line number Diff line number Diff line
@@ -5603,19 +5603,39 @@ int nfs4_proc_destroy_session(struct nfs4_session *session) 
	return status;

}



/*

 * With sessions, the client is not marked ready until after a

 * successful EXCHANGE_ID and CREATE_SESSION.

 *

 * Map errors cl_cons_state errors to EPROTONOSUPPORT to indicate

 * other versions of NFS can be tried.

 */

static int nfs41_check_session_ready(struct nfs_client *clp)

{

	int ret;

	

	if (clp->cl_cons_state == NFS_CS_SESSION_INITING) {

		ret = nfs4_client_recover_expired_lease(clp);

		if (ret)

			return ret;

	}

	if (clp->cl_cons_state < NFS_CS_READY)

		return -EPROTONOSUPPORT;

	return 0;

}



int nfs4_init_session(struct nfs_server *server)

{

	struct nfs_client *clp = server->nfs_client;

	struct nfs4_session *session;

	unsigned int rsize, wsize;

	int ret;



	if (!nfs4_has_session(clp))

		return 0;



	session = clp->cl_session;

	if (!test_and_clear_bit(NFS4_SESSION_INITING, &session->session_state))

		return 0;

	spin_lock(&clp->cl_lock);

	if (test_and_clear_bit(NFS4_SESSION_INITING, &session->session_state)) {



		rsize = server->rsize;

		if (rsize == 0)
@@ -5626,30 +5646,35 @@ int nfs4_init_session(struct nfs_server *server) 


		session->fc_attrs.max_rqst_sz = wsize + nfs41_maxwrite_overhead;

		session->fc_attrs.max_resp_sz = rsize + nfs41_maxread_overhead;

	}

	spin_unlock(&clp->cl_lock);



	ret = nfs4_recover_expired_lease(server);

	if (!ret)

		ret = nfs4_check_client_ready(clp);

	return ret;

	return nfs41_check_session_ready(clp);

}



int nfs4_init_ds_session(struct nfs_client *clp)

int nfs4_init_ds_session(struct nfs_client *clp, unsigned long lease_time)

{

	struct nfs4_session *session = clp->cl_session;

	int ret;



	if (!test_and_clear_bit(NFS4_SESSION_INITING, &session->session_state))

		return 0;

	spin_lock(&clp->cl_lock);

	if (test_and_clear_bit(NFS4_SESSION_INITING, &session->session_state)) {

		/*

		 * Do not set NFS_CS_CHECK_LEASE_TIME instead set the

		 * DS lease to be equal to the MDS lease.

		 */

		clp->cl_lease_time = lease_time;

		clp->cl_last_renewal = jiffies;

	}

	spin_unlock(&clp->cl_lock);



	ret = nfs4_client_recover_expired_lease(clp);

	if (!ret)

	ret = nfs41_check_session_ready(clp);

	if (ret)

		return ret;

	/* Test for the DS role */

	if (!is_ds_client(clp))

			ret = -ENODEV;

	if (!ret)

		ret = nfs4_check_client_ready(clp);

	return ret;



		return -ENODEV;

	return 0;

}

EXPORT_SYMBOL_GPL(nfs4_init_ds_session);