nfsd: add more information to client info file

Add ip address, full client-provided identifier, and minor version.
There's much more that could possibly be useful but this is a start.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4state.c

@@ -42,6 +42,7 @@
 #include <linux/sunrpc/svcauth_gss.h>
 #include <linux/sunrpc/addr.h>
 #include <linux/jhash.h>
+#include <linux/string_helpers.h>
 #include "xdr4.h"
 #include "xdr4cb.h"
 #include "vfs.h"
@@ -2214,6 +2215,13 @@ find_stateid_by_type(struct nfs4_client *cl, stateid_t *t, char typemask)
 	return s;
 }
 
+static void seq_quote_mem(struct seq_file *m, char *data, int len)
+{
+	seq_printf(m, "\"");
+	seq_escape_mem_ascii(m, data, len);
+	seq_printf(m, "\"");
+}
+
 static int client_info_show(struct seq_file *m, void *v)
 {
 	struct inode *inode = m->private;
@@ -2227,6 +2235,10 @@ static int client_info_show(struct seq_file *m, void *v)
 	clp = container_of(nc, struct nfs4_client, cl_nfsdfs);
 	memcpy(&clid, &clp->cl_clientid, sizeof(clid));
 	seq_printf(m, "clientid: 0x%llx\n", clid);
+	seq_printf(m, "address: \"%pISpc\"\n", (struct sockaddr *)&clp->cl_addr);
+	seq_printf(m, "name: ");
+	seq_quote_mem(m, clp->cl_name.data, clp->cl_name.len);
+	seq_printf(m, "\nminor version: %d\n", clp->cl_minorversion);
 	drop_client(clp);
 
 	return 0;