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: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever
2007-02-06 18:26:11 -05:00
committed by Trond Myklebust
parent a301b77771
commit 43d78ef2ba
4 changed files with 20 additions and 3 deletions

View File

@@ -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));