Commit 202c312d authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4: Fix NFSv4 trunking discovery 



If walking the list in nfs4[01]_walk_client_list fails, then the most
likely explanation is that the server dropped the clientid before we
actually managed to confirm it. As long as our nfs_client is the very
last one in the list to be tested, the caller can be assured that this
is the case when the final return value is NFS4ERR_STALE_CLIENTID.

Reported-by: default avatarBen Greear <greearb@candelatech.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org [>=3.7]
Tested-by: default avatarBen Greear <greearb@candelatech.com>
parent 4ae19c2d

fs/nfs/nfs4client.c

+7 −19
Original line number Diff line number Diff line
@@ -352,14 +352,8 @@ int nfs40_walk_client_list(struct nfs_client *new, 
	}

	spin_unlock(&nn->nfs_client_lock);



	/* No match found. The server lost our clientid */

out:

	/*

	 * No matching nfs_client found.  This should be impossible,

	 * because the new nfs_client has already been added to

	 * nfs_client_list by nfs_get_client().

	 *

	 * Don't BUG(), since the caller is holding a mutex.

	 */

	if (prev)

		nfs_put_client(prev);

	dprintk("NFS: <-- %s status = %d\n", __func__, status);
@@ -430,7 +424,7 @@ int nfs41_walk_client_list(struct nfs_client *new, 
{

	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);

	struct nfs_client *pos, *n, *prev = NULL;

	int error;

	int status = -NFS4ERR_STALE_CLIENTID;



	spin_lock(&nn->nfs_client_lock);

	list_for_each_entry_safe(pos, n, &nn->nfs_client_list, cl_share_link) {
@@ -446,8 +440,8 @@ int nfs41_walk_client_list(struct nfs_client *new, 
				nfs_put_client(prev);

			prev = pos;



			error = nfs_wait_client_init_complete(pos);

			if (error < 0) {

			status = nfs_wait_client_init_complete(pos);

			if (status < 0) {

				nfs_put_client(pos);

				spin_lock(&nn->nfs_client_lock);

				continue;
@@ -480,16 +474,10 @@ int nfs41_walk_client_list(struct nfs_client *new, 
		return 0;

	}



	/*

	 * No matching nfs_client found.  This should be impossible,

	 * because the new nfs_client has already been added to

	 * nfs_client_list by nfs_get_client().

	 *

	 * Don't BUG(), since the caller is holding a mutex.

	 */

	/* No matching nfs_client found. */

	spin_unlock(&nn->nfs_client_lock);

	pr_err("NFS: %s Error: no matching nfs_client found\n", __func__);

	return -NFS4ERR_STALE_CLIENTID;

	dprintk("NFS: <-- %s status = %d\n", __func__, status);

	return status;

}

#endif	/* CONFIG_NFS_V4_1 */

fs/nfs/nfs4state.c

+2 −6
Original line number Diff line number Diff line
@@ -136,16 +136,11 @@ int nfs40_discover_server_trunking(struct nfs_client *clp, 
	clp->cl_confirm = clid.confirm;



	status = nfs40_walk_client_list(clp, result, cred);

	switch (status) {

	case -NFS4ERR_STALE_CLIENTID:

		set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);

	case 0:

	if (status == 0) {

		/* Sustain the lease, even if it's empty.  If the clientid4

		 * goes stale it's of no use for trunking discovery. */

		nfs4_schedule_state_renewal(*result);

		break;

	}



out:

	return status;

}
@@ -1863,6 +1858,7 @@ again: 
	case -ETIMEDOUT:

	case -EAGAIN:

		ssleep(1);

	case -NFS4ERR_STALE_CLIENTID:

		dprintk("NFS: %s after status %d, retrying\n",

			__func__, status);

		goto again;

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