On Jan 5, 2010, at 3:41 PM, Steve Dickson wrote:
Revised patch incorporating the code review comments...
steved.
commit a96b79f57f49ce5b4d05b6b9da79bdec03b13764
Author: Steve Dickson <steved@xxxxxxxxxx>
Date: Tue Jan 5 15:39:00 2010 -0500
showmount: Try the highest mount version then fall back to lower
ones
Showmount should try the highest mount version first then fall
back to the lower ones when the server returns a
RPC_PROGVERSMISMATCH
error. The idea being not using the lower mount versions will begin
the process of moving away from NFSv2 support.
Signed-off-by: Steve Dickson <steved@xxxxxxxxxx>
diff --git a/utils/showmount/showmount.c b/utils/showmount/showmount.c
index 418e8b9..74cf116 100644
--- a/utils/showmount/showmount.c
+++ b/utils/showmount/showmount.c
@@ -78,29 +78,36 @@ static void usage(FILE *fp, int n)
exit(n);
}
-static const char *nfs_sm_pgmtbl[] = {
+static const char *mount_pgm_tbl[] = {
"showmount",
"mount",
"mountd",
NULL,
};
+static const rpcvers_t mount_vers_tbl[] = {
+ MOUNTVERS_NFSV3,
+ MOUNTVERS_POSIX,
+ MOUNTVERS,
+};
+static const int max_vers_tblsz =
+ (sizeof(mount_vers_tbl)/sizeof(mount_vers_tbl[0]));
+
/*
* Generate an RPC client handle connected to the mountd service
* at @hostname, or die trying.
*
* Supports both AF_INET and AF_INET6 server addresses.
*/
-static CLIENT *nfs_get_mount_client(const char *hostname)
+static CLIENT *nfs_get_mount_client(const char *hostname, rpcvers_t
vers)
{
- rpcprog_t program = nfs_getrpcbyname(MOUNTPROG, nfs_sm_pgmtbl);
+ rpcprog_t program = nfs_getrpcbyname(MOUNTPROG, mount_pgm_tbl);
CLIENT *client;
- client = clnt_create(hostname, program, MOUNTVERS, "tcp");
+ client = clnt_create(hostname, program, vers, "tcp");
if (client)
return client;
-
- client = clnt_create(hostname, program, MOUNTVERS, "udp");
+ client = clnt_create(hostname, program, vers, "udp");
if (client)
return client;
@@ -123,6 +130,7 @@ int main(int argc, char **argv)
int i;
int n;
int maxlen;
+ int unsigned vers=0;
char **dumpv;
program_name = argv[0];
@@ -185,7 +193,8 @@ int main(int argc, char **argv)
break;
}
- mclient = nfs_get_mount_client(hostname);
+again:
+ mclient = nfs_get_mount_client(hostname, mount_vers_tbl[vers]);
mclient->cl_auth = authunix_create_default();
total_timeout.tv_sec = TOTAL_TIMEOUT;
total_timeout.tv_usec = 0;
@@ -197,6 +206,10 @@ int main(int argc, char **argv)
(xdrproc_t) xdr_void, NULL,
(xdrproc_t) xdr_exports, (caddr_t) &exportlist,
total_timeout);
+ if (clnt_stat == RPC_PROGVERSMISMATCH) {
+ if (++vers < max_vers_tblsz)
+ goto again;
+ }
If you're going to do this, you should destroy the clnt before
retrying. Better yet you can use CLNT_CONTROL() to change the RPC
version of the clnt on the fly... that way you don't have to destroy
the clnt and create a new one, which has to try creating both "tcp"
and "udp" in some cases, making for a long timeout each time if the
server doesn't support "tcp".
My preference however, is to do the simple thing, and use
clnt_create_vers(3t) in nfs_get_mount_client(). AFAICT you wouldn't
need any of this extra logic or the new table.
if (clnt_stat != RPC_SUCCESS) {
clnt_perror(mclient, "rpc mount export");
clnt_destroy(mclient);
@@ -232,6 +245,10 @@ int main(int argc, char **argv)
(xdrproc_t) xdr_void, NULL,
(xdrproc_t) xdr_mountlist, (caddr_t) &dumplist,
total_timeout);
+ if (clnt_stat == RPC_PROGVERSMISMATCH) {
+ if (++vers < max_vers_tblsz)
+ goto again;
+ }
if (clnt_stat != RPC_SUCCESS) {
clnt_perror(mclient, "rpc mount dump");
clnt_destroy(mclient);
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--
Chuck Lever
chuck[dot]lever[at]oracle[dot]com
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