Description:
further refine TCP socket connect behavior in the RPC client. this
patch implements the following behavior changes in the RPC client:
+ the RPC client's TCP socket connect timeout is now the same as the
RPC TCP retransmit timeout value, giving sysadmins a means to adjust
the RPC connect timeout for links with long RTTs (like, to Mars).
+ if multiple RPC requests notice the TCP transport socket is
disconnected, cause them all to wait at least RPC_REESTABLISH_TIMEOUT
seconds before retrying to connect. before, only one would wait, and
the rest would retry immediately, resulting in unpredictable behavior.
+ if an unrecognized error occurs when trying to establish a connection,
just exit without retrying. This prevents potential infinite hangs.
Apply Against:
2.5.49
Test status:
Pull ethernet cable while client is under load and watch RPC debug
output. Does not affect normal operation of RPC client.
diff -Naur 03-req_offset/include/linux/sunrpc/xprt.h 04-connect3/include/linux/sunrpc/xprt.h
--- 03-req_offset/include/linux/sunrpc/xprt.h Fri Nov 22 16:40:53 2002
+++ 04-connect3/include/linux/sunrpc/xprt.h Mon Nov 25 13:24:29 2002
@@ -45,13 +45,6 @@
#define RPC_MAX_TCP_TIMEOUT (600*HZ)
/*
- * Wait duration for an RPC TCP connection to be established. Solaris
- * NFS over TCP uses 60 seconds, for example, which is in line with how
- * long a server takes to reboot.
- */
-#define RPC_CONNECT_TIMEOUT (60*HZ)
-
-/*
* Delay an arbitrary number of seconds before attempting to reconnect
* after an error.
*/
diff -Naur 03-req_offset/net/sunrpc/clnt.c 04-connect3/net/sunrpc/clnt.c
--- 03-req_offset/net/sunrpc/clnt.c Fri Nov 22 16:40:30 2002
+++ 04-connect3/net/sunrpc/clnt.c Mon Nov 25 13:24:29 2002
@@ -557,7 +557,7 @@
if (!clnt->cl_port) {
task->tk_action = call_connect;
- task->tk_timeout = RPC_CONNECT_TIMEOUT;
+ task->tk_timeout = xprt->timeout.to_initval;
rpc_getport(task, clnt);
}
}
diff -Naur 03-req_offset/net/sunrpc/xprt.c 04-connect3/net/sunrpc/xprt.c
--- 03-req_offset/net/sunrpc/xprt.c Fri Nov 22 16:40:51 2002
+++ 04-connect3/net/sunrpc/xprt.c Mon Nov 25 13:24:29 2002
@@ -461,7 +461,7 @@
if (inet->state != TCP_ESTABLISHED) {
dprintk("RPC: %4d waiting for connection\n",
task->tk_pid);
- task->tk_timeout = RPC_CONNECT_TIMEOUT;
+ task->tk_timeout = xprt->timeout.to_initval;
/* if the socket is already closing, delay briefly */
if ((1 << inet->state) & ~(TCPF_SYN_SENT|TCPF_SYN_RECV))
task->tk_timeout = RPC_REESTABLISH_TIMEOUT;
@@ -481,7 +481,7 @@
if (inet->state != TCP_ESTABLISHED) {
xprt_close(xprt);
task->tk_status = -EAGAIN;
- goto out_write;
+ break;
}
/* Otherwise, the connection is already established. */
@@ -491,24 +491,14 @@
case -EPIPE:
xprt_close(xprt);
task->tk_status = -ENOTCONN;
- goto out_write;
+ break;
default:
- /* Report myriad other possible returns. If this file
- * system is soft mounted, just error out, like Solaris. */
+ /* Report myriad other possible returns, and exit. */
xprt_close(xprt);
- if (task->tk_client->cl_softrtry) {
- printk(KERN_WARNING
+ printk(KERN_WARNING
"RPC: error %d connecting to server %s, exiting\n",
-status, task->tk_client->cl_server);
- task->tk_status = -EIO;
- } else {
- printk(KERN_WARNING
- "RPC: error %d connecting to server %s\n",
- -status, task->tk_client->cl_server);
- rpc_delay(task, RPC_REESTABLISH_TIMEOUT);
- task->tk_status = status;
- }
break;
}
@@ -528,26 +518,37 @@
case 0:
dprintk("RPC: %4d xprt_conn_status: connection established\n",
task->tk_pid);
- goto out;
+ xprt_release_write(xprt, task);
+ return;
case -ETIMEDOUT:
dprintk("RPC: %4d xprt_conn_status: timed out\n",
task->tk_pid);
- /* prevent TCP from continuing to retry SYNs */
- xprt_close(xprt);
+ task->tk_status = -EAGAIN;
+ if (task->tk_client->cl_softrtry)
+ task->tk_status = -EIO;
+ break;
+ case -ENOTCONN:
+ dprintk("RPC: %4d xprt_conn_status: no network path\n",
+ task->tk_pid);
+ if (!task->tk_client->cl_softrtry) {
+ rpc_delay(task, RPC_REESTABLISH_TIMEOUT);
+ task->tk_status = -EAGAIN;
+ } else
+ task->tk_status = -EIO;
break;
default:
- printk(KERN_ERR "RPC: error %d connecting to server %s\n",
+ printk(KERN_WARNING
+ "RPC: error %d connecting to server %s, exiting\n",
-task->tk_status, task->tk_client->cl_server);
- xprt_close(xprt);
- rpc_delay(task, RPC_REESTABLISH_TIMEOUT);
break;
}
- /* if soft mounted, cause this RPC to fail */
- if (task->tk_client->cl_softrtry)
- task->tk_status = -EIO;
+ /* prevent TCP from continuing to retry SYNs */
+ xprt_close(xprt);
- out:
- xprt_release_write(xprt, task);
+ /* if we're retrying, hold the write lock to prevent other
+ * requests from retrying the connect */
+ if (task->tk_status != -EAGAIN)
+ xprt_release_write(xprt, task);
}
/*
-
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This archive was generated by hypermail 2b29 : Sat Nov 30 2002 - 22:00:14 EST