On Jan 5, 2010, at 1:38 PM, Steve Dickson wrote:
On 01/05/2010 12:31 PM, Chuck Lever wrote:
On Jan 4, 2010, at 8:34 PM, Dan McGee wrote:
A lot of people don't have anything below v3 enabled, so showmount
is
completely unusable. Try v3 {tcp, udp} first; if they don't work,
fall
back
to v1 {tcp, udp}; if those don't work then just fail as before.
I don't see any immediate problems with this.
Well I do have a bz request that we stop using the lower mount
version so we can move away from NFSv2 support... so here is
my version of this patch...
Comments??
steved.
Author: Steve Dickson <steved@xxxxxxxxxx>
Date: Tue Jan 5 13:29:07 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..17224a6 100644
--- a/utils/showmount/showmount.c
+++ b/utils/showmount/showmount.c
@@ -85,22 +85,29 @@ static const char *nfs_sm_pgmtbl[] = {
NULL,
};
+static const int mount_vers[] = {
RPC version numbers are rpcvers_t, not int.
The array above this one is called "nfs_sm_pgmtbl"... to be consistent
with existing code you should name this one "nfs_sm_verstbl".
+ MOUNTVERS_NFSV3,
+ MOUNTVERS_POSIX,
+ MOUNTVERS,
+};
+static const int max_vers = (sizeof(mount_vers)/
sizeof(mount_vers[0]));
Array indices are unsigned.
Calling this "max_vers" suggests it's actually a version number, and
not an index into the version array; that's confusing.
The array above this one has a NULL entry as it's final element. To
be consistent with existing code, you should copy that logic for this
array instead of using a separate "max_vers" variable.
+
/*
* 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, int vers)
RPC version numbers are rpcvers_t, not int. At the very least,
clnt_create(3t) takes an unsigned version number argument.
{
rpcprog_t program = nfs_getrpcbyname(MOUNTPROG, nfs_sm_pgmtbl);
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;
@@ -122,7 +129,7 @@ int main(int argc, char **argv)
mountlist list;
int i;
int n;
- int maxlen;
+ int maxlen, vers=0;
Array indices are unsigned integers.
Calling this "vers" suggests it's actually a version number, and not
an index into the version array; that's confusing.
char **dumpv;
program_name = argv[0];
@@ -185,7 +192,8 @@ int main(int argc, char **argv)
break;
}
- mclient = nfs_get_mount_client(hostname);
+again:
+ mclient = nfs_get_mount_client(hostname, mount_vers[vers]);
mclient->cl_auth = authunix_create_default();
total_timeout.tv_sec = TOTAL_TIMEOUT;
total_timeout.tv_usec = 0;
@@ -197,6 +205,10 @@ 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)
+ goto again;
+ }
clnt_create(3t) should tell you if the requested version number is
working; libtirpc's version does a NULLPROC call, for example. It
would be simpler to move this check into nfs_get_mount_client(), then
you wouldn't need the retry loop here.
But nfs_get_mount_client() already doesn't care why the
clnt_create(3t) call fails, it just retries the creation with
different parameters if it didn't succeed. Do we really care enough
to retry _only_ if the specific RPC version isn't available? We use
the same procedure number with the same arguments and the same results
for all three protocol versions, yes?
if (clnt_stat != RPC_SUCCESS) {
clnt_perror(mclient, "rpc mount export");
clnt_destroy(mclient);
@@ -232,6 +244,10 @@ 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)
+ goto again;
+ }
if (clnt_stat != RPC_SUCCESS) {
clnt_perror(mclient, "rpc mount dump");
clnt_destroy(mclient);
--
Chuck Lever
chuck[dot]lever[at]oracle[dot]com
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