Commit b7f7a66e authored by Chuck Lever's avatar Chuck Lever Committed by Trond Myklebust
Browse files

NFS: Support NFS4ERR_LEASE_MOVED recovery in state manager 



A migration on the FSID in play for the current NFS operation
is reported via the error status code NFS4ERR_MOVED.

"Lease moved" means that a migration has occurred on some other
FSID than the one for the current operation.  It's a signal that
the client should take action immediately to handle a migration
that it may not have noticed otherwise.  This is so that the
client's lease does not expire unnoticed on the destination server.

In NFSv4.0, a moved lease is reported with the NFS4ERR_LEASE_MOVED
error status code.

To recover from NFS4ERR_LEASE_MOVED, check each FSID for that server
to see if it is still present.  Invoke nfs4_try_migration() if the
FSID is no longer present on the server.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 44c99933

fs/nfs/nfs4_fs.h

+2 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ enum nfs4_client_state { 
	NFS4CLNT_PURGE_STATE,

	NFS4CLNT_BIND_CONN_TO_SESSION,

	NFS4CLNT_MOVED,

	NFS4CLNT_LEASE_MOVED,

};



#define NFS4_RENEW_TIMEOUT		0x01
@@ -425,6 +426,7 @@ extern void nfs4_schedule_state_manager(struct nfs_client *); 
extern void nfs4_schedule_path_down_recovery(struct nfs_client *clp);

extern int nfs4_schedule_stateid_recovery(const struct nfs_server *, struct nfs4_state *);

extern int nfs4_schedule_migration_recovery(const struct nfs_server *);

extern void nfs4_schedule_lease_moved_recovery(struct nfs_client *);

extern void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags);

extern void nfs41_handle_server_scope(struct nfs_client *,

				      struct nfs41_server_scope **);

fs/nfs/nfs4state.c

+72 −1
Original line number Diff line number Diff line
@@ -1233,6 +1233,22 @@ int nfs4_schedule_migration_recovery(const struct nfs_server *server) 
}

EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);



/**

 * nfs4_schedule_lease_moved_recovery - start lease-moved recovery

 *

 * @clp: server to check for moved leases

 *

 */

void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)

{

	dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",

		__func__, clp->cl_clientid, clp->cl_hostname);



	set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);

	nfs4_schedule_state_manager(clp);

}

EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);



int nfs4_wait_clnt_recover(struct nfs_client *clp)

{

	int res;
@@ -1661,7 +1677,6 @@ static int nfs4_recovery_handle_error(struct nfs_client *clp, int error) 
			nfs4_state_end_reclaim_reboot(clp);

			break;

		case -NFS4ERR_STALE_CLIENTID:

		case -NFS4ERR_LEASE_MOVED:

			set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);

			nfs4_state_clear_reclaim_reboot(clp);

			nfs4_state_start_reclaim_reboot(clp);
@@ -1975,6 +1990,55 @@ restart: 
	return 0;

}



/*

 * Test each nfs_server on the clp's cl_superblocks list to see

 * if it's moved to another server.  Stop when the server no longer

 * returns NFS4ERR_LEASE_MOVED.

 */

static int nfs4_handle_lease_moved(struct nfs_client *clp)

{

	const struct nfs4_state_maintenance_ops *ops =

				clp->cl_mvops->state_renewal_ops;

	struct nfs_server *server;

	struct rpc_cred *cred;



	dprintk("%s: lease moved reported on \"%s\"\n", __func__,

			clp->cl_hostname);



	spin_lock(&clp->cl_lock);

	cred = ops->get_state_renewal_cred_locked(clp);

	spin_unlock(&clp->cl_lock);

	if (cred == NULL)

		return -NFS4ERR_NOENT;



	clp->cl_mig_gen++;

restart:

	rcu_read_lock();

	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {

		struct inode *inode;

		int status;



		if (server->mig_gen == clp->cl_mig_gen)

			continue;

		server->mig_gen = clp->cl_mig_gen;



		rcu_read_unlock();



		inode = server->super->s_root->d_inode;

		status = nfs4_proc_fsid_present(inode, cred);

		if (status != -NFS4ERR_MOVED)

			goto restart;	/* wasn't this one */

		if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)

			goto restart;	/* there are more */

		goto out;

	}

	rcu_read_unlock();



out:

	put_rpccred(cred);

	return 0;

}



/**

 * nfs4_discover_server_trunking - Detect server IP address trunking

 *
@@ -2312,6 +2376,13 @@ static void nfs4_state_manager(struct nfs_client *clp) 
				goto out_error;

		}



		if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {

			section = "lease moved";

			status = nfs4_handle_lease_moved(clp);

			if (status < 0)

				goto out_error;

		}



		/* First recover reboot state... */

		if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {

			section = "reclaim reboot";

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