Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4b21d0de authored by J. Bruce Fields's avatar J. Bruce Fields
Browse files

nfsd4: allow 4.0 clients to change callback path 



The rfc allows a client to change the callback parameters, but we didn't
previously implement it.

Teach the callbacks to rerun themselves (by placing themselves on a
workqueue) when they recognize that their rpc task has been killed and
that the callback connection has changed.

Then we can change the callback connection by setting up a new rpc
client, modifying the nfs4 client to point at it, waiting for any work
in progress to complete, and then shutting down the old client.

Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
parent 2bf23875

fs/nfsd/nfs4callback.c

+20 −9
Original line number Diff line number Diff line
@@ -457,9 +457,8 @@ static int max_cb_time(void) 
/* Reference counting, callback cleanup, etc., all look racy as heck.

 * And why is cl_cb_set an atomic? */



int setup_callback_client(struct nfs4_client *clp)

int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *cb)

{

	struct nfs4_cb_conn *cb = &clp->cl_cb_conn;

	struct rpc_timeout	timeparms = {

		.to_initval	= max_cb_time(),

		.to_retries	= 0,
@@ -481,7 +480,7 @@ int setup_callback_client(struct nfs4_client *clp) 
	if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))

		return -EINVAL;

	if (cb->cb_minorversion) {

		args.bc_xprt = clp->cl_cb_conn.cb_xprt;

		args.bc_xprt = cb->cb_xprt;

		args.protocol = XPRT_TRANSPORT_BC_TCP;

	}

	/* Create RPC client */
@@ -491,7 +490,7 @@ int setup_callback_client(struct nfs4_client *clp) 
			PTR_ERR(client));

		return PTR_ERR(client);

	}

	clp->cl_cb_client = client;

	nfsd4_set_callback_client(clp, client);

	return 0;



}
@@ -548,14 +547,13 @@ void do_probe_callback(struct nfs4_client *clp) 
/*

 * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...

 */

void

nfsd4_probe_callback(struct nfs4_client *clp)

void nfsd4_probe_callback(struct nfs4_client *clp, struct nfs4_cb_conn *cb)

{

	int status;



	BUG_ON(atomic_read(&clp->cl_cb_set));



	status = setup_callback_client(clp);

	status = setup_callback_client(clp, cb);

	if (status) {

		warn_no_callback_path(clp, status);

		return;
@@ -645,18 +643,32 @@ static void nfsd4_cb_done(struct rpc_task *task, void *calldata) 
	}

}





static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)

{

	struct nfs4_delegation *dp = calldata;

	struct nfs4_client *clp = dp->dl_client;

	struct rpc_clnt *current_rpc_client = clp->cl_cb_client;



	nfsd4_cb_done(task, calldata);



	if (current_rpc_client == NULL) {

		/* We're shutting down; give up. */

		/* XXX: err, or is it ok just to fall through

		 * and rpc_restart_call? */

		return;

	}



	switch (task->tk_status) {

	case -EIO:

		/* Network partition? */

		atomic_set(&clp->cl_cb_set, 0);

		warn_no_callback_path(clp, task->tk_status);

		if (current_rpc_client != task->tk_client) {

			/* queue a callback on the new connection: */

			nfsd4_cb_recall(dp);

			return;

		}

	case -EBADHANDLE:

	case -NFS4ERR_BAD_STATEID:

		/* Race: client probably got cb_recall
@@ -705,8 +717,7 @@ void nfsd4_destroy_callback_queue(void) 
	destroy_workqueue(callback_wq);

}



void nfsd4_set_callback_client(struct nfs4_client *clp, struct rpc_clnt

*new)

void nfsd4_set_callback_client(struct nfs4_client *clp, struct rpc_clnt *new)

{

	struct rpc_clnt *old = clp->cl_cb_client;

fs/nfsd/nfs4state.c

+3 −4
Original line number Diff line number Diff line
@@ -1312,7 +1312,7 @@ nfsd4_create_session(struct svc_rqst *rqstp, 
				cstate->minorversion;

			unconf->cl_cb_conn.cb_prog = cr_ses->callback_prog;

			unconf->cl_cb_seq_nr = 1;

			nfsd4_probe_callback(unconf);

			nfsd4_probe_callback(unconf, &unconf->cl_cb_conn);

		}

		conf = unconf;

	} else {
@@ -1605,9 +1605,8 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp, 
		if (!same_creds(&conf->cl_cred, &unconf->cl_cred))

			status = nfserr_clid_inuse;

		else {

			/* XXX: We just turn off callbacks until we can handle

			  * change request correctly. */

			atomic_set(&conf->cl_cb_set, 0);

			nfsd4_probe_callback(conf, &unconf->cl_cb_conn);

			expire_client(unconf);

			status = nfs_ok;
@@ -1641,7 +1640,7 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp, 
			}

			move_to_confirmed(unconf);

			conf = unconf;

			nfsd4_probe_callback(conf);

			nfsd4_probe_callback(conf, &conf->cl_cb_conn);

			status = nfs_ok;

		}

	} else if ((!conf || (conf && !same_verf(&conf->cl_confirm, &confirm)))

fs/nfsd/state.h

+1 −1
Original line number Diff line number Diff line
@@ -390,7 +390,7 @@ extern int nfs4_in_grace(void); 
extern __be32 nfs4_check_open_reclaim(clientid_t *clid);

extern void nfs4_free_stateowner(struct kref *kref);

extern int set_callback_cred(void);

extern void nfsd4_probe_callback(struct nfs4_client *clp);

extern void nfsd4_probe_callback(struct nfs4_client *clp, struct nfs4_cb_conn *);

extern void nfsd4_do_callback_rpc(struct work_struct *);

extern void nfsd4_cb_recall(struct nfs4_delegation *dp);

extern int nfsd4_create_callback_queue(void);