Chuck Lever <chuck.lever@xxxxxxxxxx> wrote:
> On Nov 12, 2011, at 1:49 PM, Jim Rees wrote:
>
>> The question for us is how long should an nfsroot client wait for the
> server
>> to reply. It sounds like the client used to wait longer than it does now.
>
> Before, the client performed the GETPORT(NFS) step synchronously, first. This
> took 30 seconds or so to timeout. When it did, the client decided to proceed
> with port 2049. Then it went on to do the other mount tasks, and at the point
> had waited long enough that these tasks did not time out while waiting for the
> switch port.
>
>> It seems to me the client should wait at least 90 seconds so that the
>> situation you're in (servers on non-portfast ports) will work. I would
>> think they should wait indefinitely, since there's not much else they
> can
>> do.
>
> It should be simple to wrap the (MNT(mnt), NFS(getroot)) steps in a while(true)
> loop. Would mount_root_nfs() be the right place for this?
>
I thought it would be harder and I had no time to look inside the kernel but now I wrote a patch:
The kernel tries to create the MNT RPC client not once as before but three times - then it gives up.
Third time lucky... ;-)
In my case the 2. MNT request is successful:
---
[ 71.594744] ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 72.617007] IP-Config: Complete:
[ 72.617077] device=eth0, addr=137.226.167.242, mask=255.255.255.224, gw=137.226.167.225,
[ 72.617278] host=137.226.167.242, domain=, nis-domain=(none),
[ 72.617393] bootserver=255.255.255.255, rootserver=137.226.167.241, rootpath=
[ 72.617741] Root-NFS: nfsroot=/srv/nfs/cluster2
[ 72.618010] NFS: nfs mount opts='udp,nolock,addr=137.226.167.241'
[ 72.618147] NFS: parsing nfs mount option 'udp'
[ 72.618187] NFS: parsing nfs mount option 'nolock'
[ 72.618233] NFS: parsing nfs mount option 'addr=137.226.167.241'
[ 72.618301] NFS: MNTPATH: '/srv/nfs/cluster2'
[ 72.618335] NFS: sending MNT request for 137.226.167.241:/srv/nfs/cluster2
[ 72.618383] NFS: 1. MNT request
[ 73.691872] e1000e: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx
[ 73.711988] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 107.697332] NFS: 2. MNT request
[ 107.704591] NFS: received 1 auth flavors
[ 107.704653] NFS: auth flavor[0]: 1
[ 107.704834] NFS: MNT request succeeded
[ 107.704897] NFS: using auth flavor 1
[ 107.711857] VFS: Mounted root (nfs filesystem) on device 0:13.
INIT: version 2.88 booting
---
So many thanks again for your help and your very helpful hints!
Regards,
Lukas
PS: That's what I've done:
--- linux-2.6.39.4/fs/nfs/mount_clnt.c 2011-08-03 21:43:28.000000000 +0200
+++ linux-2.6.39.4-fix/fs/nfs/mount_clnt.c 2011-11-13 01:58:13.000000000 +0100
@@ -164,6 +164,7 @@
};
struct rpc_clnt *mnt_clnt;
int status;
+ int attempt = 0;
dprintk("NFS: sending MNT request for %s:%s\n",
(info->hostname ? info->hostname : "server"),
@@ -172,7 +173,13 @@
if (info->noresvport)
args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
- mnt_clnt = rpc_create(&args);
+ do {
+ attempt++;
+ dprintk("NFS: %d. MNT request\n", attempt);
+ mnt_clnt = rpc_create(&args);
+ } while (IS_ERR(mnt_clnt) && attempt < 3);
+
+
if (IS_ERR(mnt_clnt))
goto out_clnt_err;
--
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
