提交 43d78ef2 编写于 作者: C Chuck Lever 提交者: Trond Myklebust

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=6Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
上级 a301b777
......@@ -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));
......
......@@ -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 *,
......
......@@ -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;
}
......
......@@ -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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