[PATCH] NFS: use a constant value for TCP retransmit timeouts

Implement a best practice: don't use exponential backoff when computing
 retransmit timeout values on TCP connections, but simply retransmit
 at regular intervals.

 This also fixes a bug introduced when xprt_reset_majortimeo() was added.

 Test-plan:
 Enable RPC debugging and watch timeout behavior on a NFS/TCP mount.

 Version: Thu, 11 Aug 2005 16:02:19 -0400

 Signed-off-by: Chuck Lever <cel@netapp.com>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever 2005-08-11 16:25:14 -04:00 committed by Trond Myklebust
parent da35187801
commit eab5c084b8
2 changed files with 37 additions and 40 deletions

View File

@ -358,6 +358,35 @@ out_no_root:
return no_root_error;
}
static void nfs_init_timeout_values(struct rpc_timeout *to, int proto, unsigned int timeo, unsigned int retrans)
{
to->to_initval = timeo * HZ / 10;
to->to_retries = retrans;
if (!to->to_retries)
to->to_retries = 2;
switch (proto) {
case IPPROTO_TCP:
if (!to->to_initval)
to->to_initval = 60 * HZ;
if (to->to_initval > RPC_MAX_TCP_TIMEOUT)
to->to_initval = RPC_MAX_TCP_TIMEOUT;
to->to_increment = to->to_initval;
to->to_maxval = to->to_initval + (to->to_increment * to->to_retries);
to->to_exponential = 0;
break;
case IPPROTO_UDP:
default:
if (!to->to_initval)
to->to_initval = 11 * HZ / 10;
if (to->to_initval > RPC_MAX_UDP_TIMEOUT)
to->to_initval = RPC_MAX_UDP_TIMEOUT;
to->to_maxval = RPC_MAX_UDP_TIMEOUT;
to->to_exponential = 1;
break;
}
}
/*
* Create an RPC client handle.
*/
@ -367,22 +396,12 @@ nfs_create_client(struct nfs_server *server, const struct nfs_mount_data *data)
struct rpc_timeout timeparms;
struct rpc_xprt *xprt = NULL;
struct rpc_clnt *clnt = NULL;
int tcp = (data->flags & NFS_MOUNT_TCP);
int proto = (data->flags & NFS_MOUNT_TCP) ? IPPROTO_TCP : IPPROTO_UDP;
/* Initialize timeout values */
timeparms.to_initval = data->timeo * HZ / 10;
timeparms.to_retries = data->retrans;
timeparms.to_maxval = tcp ? RPC_MAX_TCP_TIMEOUT : RPC_MAX_UDP_TIMEOUT;
timeparms.to_exponential = 1;
if (!timeparms.to_initval)
timeparms.to_initval = (tcp ? 600 : 11) * HZ / 10;
if (!timeparms.to_retries)
timeparms.to_retries = 5;
nfs_init_timeout_values(&timeparms, proto, data->timeo, data->retrans);
/* create transport and client */
xprt = xprt_create_proto(tcp ? IPPROTO_TCP : IPPROTO_UDP,
&server->addr, &timeparms);
xprt = xprt_create_proto(proto, &server->addr, &timeparms);
if (IS_ERR(xprt)) {
dprintk("%s: cannot create RPC transport. Error = %ld\n",
__FUNCTION__, PTR_ERR(xprt));
@ -1674,7 +1693,7 @@ static int nfs4_fill_super(struct super_block *sb, struct nfs4_mount_data *data,
struct rpc_clnt *clnt = NULL;
struct rpc_timeout timeparms;
rpc_authflavor_t authflavour;
int proto, err = -EIO;
int err = -EIO;
sb->s_blocksize_bits = 0;
sb->s_blocksize = 0;
@ -1692,30 +1711,8 @@ static int nfs4_fill_super(struct super_block *sb, struct nfs4_mount_data *data,
server->acdirmax = data->acdirmax*HZ;
server->rpc_ops = &nfs_v4_clientops;
/* Initialize timeout values */
timeparms.to_initval = data->timeo * HZ / 10;
timeparms.to_retries = data->retrans;
timeparms.to_exponential = 1;
if (!timeparms.to_retries)
timeparms.to_retries = 5;
proto = data->proto;
/* Which IP protocol do we use? */
switch (proto) {
case IPPROTO_TCP:
timeparms.to_maxval = RPC_MAX_TCP_TIMEOUT;
if (!timeparms.to_initval)
timeparms.to_initval = 600 * HZ / 10;
break;
case IPPROTO_UDP:
timeparms.to_maxval = RPC_MAX_UDP_TIMEOUT;
if (!timeparms.to_initval)
timeparms.to_initval = 11 * HZ / 10;
break;
default:
return -EINVAL;
}
nfs_init_timeout_values(&timeparms, data->proto, data->timeo, data->retrans);
clp = nfs4_get_client(&server->addr.sin_addr);
if (!clp) {
@ -1740,7 +1737,7 @@ static int nfs4_fill_super(struct super_block *sb, struct nfs4_mount_data *data,
down_write(&clp->cl_sem);
if (IS_ERR(clp->cl_rpcclient)) {
xprt = xprt_create_proto(proto, &server->addr, &timeparms);
xprt = xprt_create_proto(data->proto, &server->addr, &timeparms);
if (IS_ERR(xprt)) {
up_write(&clp->cl_sem);
err = PTR_ERR(xprt);

View File

@ -1453,7 +1453,7 @@ xprt_default_timeout(struct rpc_timeout *to, int proto)
if (proto == IPPROTO_UDP)
xprt_set_timeout(to, 5, 5 * HZ);
else
xprt_set_timeout(to, 5, 60 * HZ);
xprt_set_timeout(to, 2, 60 * HZ);
}
/*
@ -1464,7 +1464,7 @@ xprt_set_timeout(struct rpc_timeout *to, unsigned int retr, unsigned long incr)
{
to->to_initval =
to->to_increment = incr;
to->to_maxval = incr * retr;
to->to_maxval = to->to_initval + (incr * retr);
to->to_retries = retr;
to->to_exponential = 0;
}