Commit 43d78ef2 authored by Chuck Lever's avatar Chuck Lever Committed by Trond Myklebust
Browse files

NFS: disconnect before retrying NFSv4 requests over TCP 

RFC3530 section 3.1.1 states an NFSv4 client MUST NOT send a request
twice on the same connection unless it is the NULL procedure.  Section
3.1.1 suggests that the client should disconnect and reconnect if it
wants to retry a request.

Implement this by adding an rpc_clnt flag that an ULP can use to
specify that the underlying transport should be disconnected on a
major timeout.  The NFSv4 client asserts this new flag, and requests
no retries after a minor retransmit timeout.

Note that disconnecting on a retransmit is in general not safe to do
if the RPC client does not reuse the TCP port number when reconnecting.

See http://bugzilla.linux-nfs.org/show_bug.cgi?id=6



Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent a301b777

fs/nfs/client.c

+6 −3
Original line number Diff line number Diff line
@@ -394,7 +394,8 @@ static void nfs_init_timeout_values(struct rpc_timeout *to, int proto, 
static int nfs_create_rpc_client(struct nfs_client *clp, int proto,

						unsigned int timeo,

						unsigned int retrans,

						rpc_authflavor_t flavor)

						rpc_authflavor_t flavor,

						int flags)

{

	struct rpc_timeout	timeparms;

	struct rpc_clnt		*clnt = NULL;
@@ -407,6 +408,7 @@ static int nfs_create_rpc_client(struct nfs_client *clp, int proto, 
		.program	= &nfs_program,

		.version	= clp->rpc_ops->version,

		.authflavor	= flavor,

		.flags		= flags,

	};



	if (!IS_ERR(clp->cl_rpcclient))
@@ -548,7 +550,7 @@ static int nfs_init_client(struct nfs_client *clp, const struct nfs_mount_data * 
	 * - RFC 2623, sec 2.3.2

	 */

	error = nfs_create_rpc_client(clp, proto, data->timeo, data->retrans,

			RPC_AUTH_UNIX);

					RPC_AUTH_UNIX, 0);

	if (error < 0)

		goto error;

	nfs_mark_client_ready(clp, NFS_CS_READY);
@@ -868,7 +870,8 @@ static int nfs4_init_client(struct nfs_client *clp, 
	/* Check NFS protocol revision and initialize RPC op vector */

	clp->rpc_ops = &nfs_v4_clientops;



	error = nfs_create_rpc_client(clp, proto, timeo, retrans, authflavour);

	error = nfs_create_rpc_client(clp, proto, timeo, retrans, authflavour,

					RPC_CLNT_CREATE_DISCRTRY);

	if (error < 0)

		goto error;

	memcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));

include/linux/sunrpc/clnt.h

+2 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ struct rpc_clnt { 


	unsigned int		cl_softrtry : 1,/* soft timeouts */

				cl_intr     : 1,/* interruptible */

				cl_discrtry : 1,/* disconnect before retry */

				cl_autobind : 1,/* use getport() */

				cl_oneshot  : 1,/* dispose after use */

				cl_dead     : 1;/* abandoned */
@@ -111,6 +112,7 @@ struct rpc_create_args { 
#define RPC_CLNT_CREATE_ONESHOT		(1UL << 3)

#define RPC_CLNT_CREATE_NONPRIVPORT	(1UL << 4)

#define RPC_CLNT_CREATE_NOPING		(1UL << 5)

#define RPC_CLNT_CREATE_DISCRTRY	(1UL << 6)



struct rpc_clnt *rpc_create(struct rpc_create_args *args);

struct rpc_clnt	*rpc_bind_new_program(struct rpc_clnt *,

net/sunrpc/clnt.c

+2 −0
Original line number Diff line number Diff line
@@ -249,6 +249,8 @@ struct rpc_clnt *rpc_create(struct rpc_create_args *args) 
		clnt->cl_autobind = 1;

	if (args->flags & RPC_CLNT_CREATE_ONESHOT)

		clnt->cl_oneshot = 1;

	if (args->flags & RPC_CLNT_CREATE_DISCRTRY)

		clnt->cl_discrtry = 1;



	return clnt;

}

net/sunrpc/xprt.c

+10 −0
Original line number Diff line number Diff line
@@ -735,6 +735,16 @@ void xprt_transmit(struct rpc_task *task) 
			xprt_reset_majortimeo(req);

			/* Turn off autodisconnect */

			del_singleshot_timer_sync(&xprt->timer);

		} else {

			/* If all request bytes have been sent,

			 * then we must be retransmitting this one */

			if (!req->rq_bytes_sent) {

				if (task->tk_client->cl_discrtry) {

					xprt_disconnect(xprt);

					task->tk_status = -ENOTCONN;

					return;

				}

			}

		}

	} else if (!req->rq_bytes_sent)

		return;

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