4 files changed, 67 insertions, 5 deletions

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 592b5583aa3a..1506adf4d4ed 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -304,6 +304,7 @@ static void nfs_free_client(struct nfs_client *clp)
         put_net(clp->net);
         kfree(clp->cl_hostname);
         kfree(clp->server_scope);
+        kfree(clp->impl_id);
         kfree(clp);
 
         dprintk("<-- nfs_free_client()\n");
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 20c3bb06763a..90a17cc3ebc9 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4950,11 +4950,24 @@ int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred)
                 goto out;
         }
 
+        res.impl_id = kzalloc(sizeof(struct nfs41_impl_id), GFP_KERNEL);
+        if (unlikely(!res.impl_id)) {
+                status = -ENOMEM;
+                goto out_server_scope;
+        }
+
         status = rpc_call_sync(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
         if (!status)
                 status = nfs4_check_cl_exchange_flags(clp->cl_exchange_flags);
 
         if (!status) {
+                /* use the most recent implementation id */
+                kfree(clp->impl_id);
+                clp->impl_id = res.impl_id;
+        } else
+                kfree(res.impl_id);
+
+        if (!status) {
                 if (clp->server_scope &&
                     !nfs41_same_server_scope(clp->server_scope,
                                              res.server_scope)) {
@@ -4970,8 +4983,16 @@ int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred)
                         goto out;
                 }
         }
+
+out_server_scope:
         kfree(res.server_scope);
 out:
+        if (clp->impl_id)
+                dprintk("%s: Server Implementation ID: "
+                        "domain: %s, name: %s, date: %llu,%u\n",
+                        __func__, clp->impl_id->domain, clp->impl_id->name,
+                        clp->impl_id->date.seconds,
+                        clp->impl_id->date.nseconds);
         dprintk("<-- %s status= %d\n", __func__, status);
         return status;
 }
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index d824aedb1237..b7c04339fdc1 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -291,7 +291,11 @@ static int nfs4_stat_to_errno(int);
                                 /* eir_server_scope<> */ \
                                 XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + 1 + \
                                 1 /* eir_server_impl_id array length */ + \
-                                0 /* ignored eir_server_impl_id contents */)
+                                1 /* nii_domain */ + \
+                                XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + \
+                                1 /* nii_name */ + \
+                                XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + \
+                                3 /* nii_date */)
 #define encode_channel_attrs_maxsz  (6 + 1 /* ca_rdma_ird.len (0) */)
 #define decode_channel_attrs_maxsz  (6 + \
                                      1 /* ca_rdma_ird.len */ + \
@@ -5256,6 +5260,7 @@ static int decode_exchange_id(struct xdr_stream *xdr,
         char *dummy_str;
         int status;
         struct nfs_client *clp = res->client;
+        uint32_t impl_id_count;
 
         status = decode_op_hdr(xdr, OP_EXCHANGE_ID);
         if (status)
@@ -5297,11 +5302,38 @@ static int decode_exchange_id(struct xdr_stream *xdr,
         memcpy(res->server_scope->server_scope, dummy_str, dummy);
         res->server_scope->server_scope_sz = dummy;
 
-        /* Throw away Implementation id array */
-        status = decode_opaque_inline(xdr, &dummy, &dummy_str);
-        if (unlikely(status))
-                return status;
+        /* Implementation Id */
+        p = xdr_inline_decode(xdr, 4);
+        if (unlikely(!p))
+                goto out_overflow;
+        impl_id_count = be32_to_cpup(p++);
 
+        if (impl_id_count) {
+                /* nii_domain */
+                status = decode_opaque_inline(xdr, &dummy, &dummy_str);
+                if (unlikely(status))
+                        return status;
+                if (unlikely(dummy > NFS4_OPAQUE_LIMIT))
+                        return -EIO;
+                memcpy(res->impl_id->domain, dummy_str, dummy);
+
+                /* nii_name */
+                status = decode_opaque_inline(xdr, &dummy, &dummy_str);
+                if (unlikely(status))
+                        return status;
+                if (unlikely(dummy > NFS4_OPAQUE_LIMIT))
+                        return -EIO;
+                memcpy(res->impl_id->name, dummy_str, dummy);
+
+                /* nii_date */
+                p = xdr_inline_decode(xdr, 12);
+                if (unlikely(!p))
+                        goto out_overflow;
+                p = xdr_decode_hyper(p, &res->impl_id->date.seconds);
+                res->impl_id->date.nseconds = be32_to_cpup(p);
+
+                /* if there's more than one entry, ignore the rest */
+        }
         return 0;
 out_overflow:
         print_overflow_msg(__func__, xdr);
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 6708f3044eb0..8154accd1168 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -809,6 +809,14 @@ static int nfs_show_stats(struct seq_file *m, struct dentry *root)
 
         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
 
+        if (nfss->nfs_client && nfss->nfs_client->impl_id) {
+                struct nfs41_impl_id *impl_id = nfss->nfs_client->impl_id;
+                seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
+                           "date='%llu,%u'",
+                           impl_id->name, impl_id->domain,
+                           impl_id->date.seconds, impl_id->date.nseconds);
+        }
+
         seq_printf(m, "\n\tcaps:\t");
         seq_printf(m, "caps=0x%x", nfss->caps);
         seq_printf(m, ",wtmult=%u", nfss->wtmult);