nfsd: fix dependency of nfsd on auth_rpcgss

Commit b0b0c0a2 "nfsd: add proc file listing kernel's gss_krb5
enctypes" added an nunnecessary dependency of nfsd on the auth_rpcgss
module.

It's a little ad hoc, but since the only piece of information nfsd needs
from rpcsec_gss_krb5 is a single static string, one solution is just to
share it with an include file.

Cc: stable@kernel.org
Reported-by: Michael Guntsche <mike@it-loops.com>
Cc: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfsctl.c

@@ -13,6 +13,7 @@
 #include <linux/lockd/lockd.h>
 #include <linux/sunrpc/clnt.h>
 #include <linux/sunrpc/gss_api.h>
+#include <linux/sunrpc/gss_krb5_enctypes.h>
 
 #include "idmap.h"
 #include "nfsd.h"
@@ -189,18 +190,10 @@ static struct file_operations export_features_operations = {
 	.release	= single_release,
 };
 
-#ifdef CONFIG_SUNRPC_GSS
+#if defined(CONFIG_SUNRPC_GSS) || defined(CONFIG_SUNRPC_GSS_MODULE)
 static int supported_enctypes_show(struct seq_file *m, void *v)
 {
-	struct gss_api_mech *k5mech;
-
-	k5mech = gss_mech_get_by_name("krb5");
-	if (k5mech == NULL)
-		goto out;
-	if (k5mech->gm_upcall_enctypes != NULL)
-		seq_printf(m, k5mech->gm_upcall_enctypes);
-	gss_mech_put(k5mech);
-out:
+	seq_printf(m, KRB5_SUPPORTED_ENCTYPES);
 	return 0;
 }
 
@@ -215,7 +208,7 @@ static struct file_operations supported_enctypes_ops = {
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
-#endif /* CONFIG_SUNRPC_GSS */
+#endif /* CONFIG_SUNRPC_GSS or CONFIG_SUNRPC_GSS_MODULE */
 
 extern int nfsd_pool_stats_open(struct inode *inode, struct file *file);
 extern int nfsd_pool_stats_release(struct inode *inode, struct file *file);
@@ -1427,9 +1420,9 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent)
 		[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
 		[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
 		[NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
-#ifdef CONFIG_SUNRPC_GSS
+#if defined(CONFIG_SUNRPC_GSS) || defined(CONFIG_SUNRPC_GSS_MODULE)
 		[NFSD_SupportedEnctypes] = {"supported_krb5_enctypes", &supported_enctypes_ops, S_IRUGO},
-#endif /* CONFIG_SUNRPC_GSS */
+#endif /* CONFIG_SUNRPC_GSS or CONFIG_SUNRPC_GSS_MODULE */
 #ifdef CONFIG_NFSD_V4
 		[NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
 		[NFSD_Gracetime] = {"nfsv4gracetime", &transaction_ops, S_IWUSR|S_IRUSR},

include/linux/sunrpc/gss_krb5_enctypes.h

+/*
+ * Dumb way to share this static piece of information with nfsd
+ */
+#define KRB5_SUPPORTED_ENCTYPES "18,17,16,23,3,1,2"

net/sunrpc/auth_gss/gss_krb5_mech.c

@@ -43,6 +43,7 @@
 #include <linux/sunrpc/gss_krb5.h>
 #include <linux/sunrpc/xdr.h>
 #include <linux/crypto.h>
+#include <linux/sunrpc/gss_krb5_enctypes.h>
 
 #ifdef RPC_DEBUG
 # define RPCDBG_FACILITY	RPCDBG_AUTH
@@ -750,7 +751,7 @@ static struct gss_api_mech gss_kerberos_mech = {
 	.gm_ops		= &gss_kerberos_ops,
 	.gm_pf_num	= ARRAY_SIZE(gss_kerberos_pfs),
 	.gm_pfs		= gss_kerberos_pfs,
-	.gm_upcall_enctypes = "18,17,16,23,3,1,2",
+	.gm_upcall_enctypes = KRB5_SUPPORTED_ENCTYPES,
 };
 
 static int __init init_kerberos_module(void)