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: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever 2013-10-17 14:13:35 -04:00 committed by Trond Myklebust
parent 44c9993384
commit b7f7a66e42
2 changed files with 74 additions and 1 deletions

View file

@ -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 **);

View file

@ -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 @@ static int nfs4_handle_migration(struct nfs_client *clp)
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";