NFSv4: Handle the NFS4ERR_CLID_INUSE error in SETCLIENTID

 Encode the AUTH flavour in the clientid, since AUTH_UNIX and AUTH_GSS
 credentials will always conflict.

 Then, strategy is to first retry after sleeping for a lease period. If
 the server then still refuses our clientid, assume we have a conflicting
 client, out there, and try bumping a "uniquifier" variable.

 Give up if we're signalled, or if we've gone through the entire range
 of uniquifiers...

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
---
 fs/nfs/nfs4proc.c      |   54 +++++++++++++++++++++++++++++--------------------
 fs/nfs/nfs4state.c     |    1 
 fs/nfs/nfs4xdr.c       |    2 -
 include/linux/nfs_fs.h |    4 +++
 4 files changed, 38 insertions(+), 23 deletions(-)

Index: linux-2.6.11/fs/nfs/nfs4proc.c
===================================================================
--- linux-2.6.11.orig/fs/nfs/nfs4proc.c
+++ linux-2.6.11/fs/nfs/nfs4proc.c
@@ -37,6 +37,7 @@
 
 #include <linux/mm.h>
 #include <linux/utsname.h>
+#include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/string.h>
 #include <linux/sunrpc/clnt.h>
@@ -2163,9 +2164,7 @@ int nfs4_handle_exception(struct nfs_ser
 
 int nfs4_proc_setclientid(struct nfs4_client *clp, u32 program, unsigned short port)
 {
-	static nfs4_verifier sc_verifier;
-	static int initialized;
-	
+	nfs4_verifier sc_verifier;
 	struct nfs4_setclientid setclientid = {
 		.sc_verifier = &sc_verifier,
 		.sc_prog = program,
@@ -2176,27 +2175,38 @@ int nfs4_proc_setclientid(struct nfs4_cl
 		.rpc_resp = clp,
 		.rpc_cred = clp->cl_cred,
 	};
+	u32 *p;
+	int loop = 0;
+	int status;
 
-	if (!initialized) {
-		struct timespec boot_time;
-		u32 *p;
-
-		initialized = 1;
-		boot_time = CURRENT_TIME;
-		p = (u32*)sc_verifier.data;
-		*p++ = htonl((u32)boot_time.tv_sec);
-		*p = htonl((u32)boot_time.tv_nsec);
-	}
-	setclientid.sc_name_len = scnprintf(setclientid.sc_name,
-			sizeof(setclientid.sc_name), "%s/%u.%u.%u.%u",
-			clp->cl_ipaddr, NIPQUAD(clp->cl_addr.s_addr));
-	setclientid.sc_netid_len = scnprintf(setclientid.sc_netid,
-			sizeof(setclientid.sc_netid), "tcp");
-	setclientid.sc_uaddr_len = scnprintf(setclientid.sc_uaddr,
-			sizeof(setclientid.sc_uaddr), "%s.%d.%d",
-			clp->cl_ipaddr, port >> 8, port & 255);
+	p = (u32*)sc_verifier.data;
+	*p++ = htonl((u32)clp->cl_boot_time.tv_sec);
+	*p = htonl((u32)clp->cl_boot_time.tv_nsec);
+
+	for(;;) {
+		setclientid.sc_name_len = scnprintf(setclientid.sc_name,
+				sizeof(setclientid.sc_name), "%s/%u.%u.%u.%u %s %u",
+				clp->cl_ipaddr, NIPQUAD(clp->cl_addr.s_addr),
+				clp->cl_cred->cr_ops->cr_name,
+				clp->cl_id_uniquifier);
+		setclientid.sc_netid_len = scnprintf(setclientid.sc_netid,
+				sizeof(setclientid.sc_netid), "tcp");
+		setclientid.sc_uaddr_len = scnprintf(setclientid.sc_uaddr,
+				sizeof(setclientid.sc_uaddr), "%s.%d.%d",
+				clp->cl_ipaddr, port >> 8, port & 255);
 
-	return rpc_call_sync(clp->cl_rpcclient, &msg, 0);
+		status = rpc_call_sync(clp->cl_rpcclient, &msg, 0);
+		if (status != -NFS4ERR_CLID_INUSE)
+			break;
+		if (signalled())
+			break;
+		if (loop++ & 1)
+			ssleep(clp->cl_lease_time + 1);
+		else
+			if (++clp->cl_id_uniquifier == 0)
+				break;
+	}
+	return status;
 }
 
 int
Index: linux-2.6.11/include/linux/nfs_fs.h
===================================================================
--- linux-2.6.11.orig/include/linux/nfs_fs.h
+++ linux-2.6.11/include/linux/nfs_fs.h
@@ -583,6 +583,9 @@ struct nfs4_client {
 	wait_queue_head_t	cl_waitq;
 	struct rpc_wait_queue	cl_rpcwaitq;
 
+	/* used for the setclientid verifier */
+	struct timespec		cl_boot_time;
+
 	/* idmapper */
 	struct idmap *		cl_idmap;
 
@@ -590,6 +593,7 @@ struct nfs4_client {
 	 * This is used to generate the clientid, and the callback address.
 	 */
 	char			cl_ipaddr[16];
+	unsigned char		cl_id_uniquifier;
 };
 
 /*
Index: linux-2.6.11/fs/nfs/nfs4state.c
===================================================================
--- linux-2.6.11.orig/fs/nfs/nfs4state.c
+++ linux-2.6.11/fs/nfs/nfs4state.c
@@ -116,6 +116,7 @@ nfs4_alloc_client(struct in_addr *addr)
 	INIT_LIST_HEAD(&clp->cl_superblocks);
 	init_waitqueue_head(&clp->cl_waitq);
 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS4 client");
+	clp->cl_boot_time = CURRENT_TIME;
 	clp->cl_state = 1 << NFS4CLNT_OK;
 	return clp;
 }
Index: linux-2.6.11/fs/nfs/nfs4xdr.c
===================================================================
--- linux-2.6.11.orig/fs/nfs/nfs4xdr.c
+++ linux-2.6.11/fs/nfs/nfs4xdr.c
@@ -3175,7 +3175,7 @@ static int decode_setclientid(struct xdr
 		READ_BUF(4);
 		READ32(len);
 		READ_BUF(len);
-		return -EEXIST;
+		return -NFSERR_CLID_INUSE;
 	} else
 		return -nfs_stat_to_errno(nfserr);