nfsd: don't allocate the versions array.

Instead of using kmalloc to allocate an array for storing active version
info, just declare an array to the max size - it is only 5 or so.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/cache.h

@@ -10,7 +10,7 @@
 #define NFSCACHE_H
 
 #include <linux/sunrpc/svc.h>
-#include "netns.h"
+#include "nfsd.h"
 
 /*
  * Representation of a reply cache entry.

fs/nfsd/netns.h

@@ -152,8 +152,8 @@ struct nfsd_net {
 	/*
 	 * Version information
 	 */
-	bool *nfsd_versions;
-	bool *nfsd4_minorversions;
+	bool nfsd_versions[NFSD_MAXVERS + 1];
+	bool nfsd4_minorversions[NFSD_SUPPORTED_MINOR_VERSION + 1];
 
 	/*
 	 * Duplicate reply cache
@@ -219,8 +219,6 @@ struct nfsd_net {
 #define nfsd_netns_ready(nn) ((nn)->sessionid_hashtbl)
 
 extern bool nfsd_support_version(int vers);
-extern void nfsd_netns_free_versions(struct nfsd_net *nn);
-
 extern unsigned int nfsd_net_id;
 
 void nfsd_copy_write_verifier(__be32 verf[2], struct nfsd_net *nn);

fs/nfsd/nfsctl.c

@@ -2231,8 +2231,9 @@ int nfsd_nl_pool_mode_get_doit(struct sk_buff *skb, struct genl_info *info)
  */
 static __net_init int nfsd_net_init(struct net *net)
 {
-	int retval;
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+	int retval;
+	int i;
 
 	retval = nfsd_export_init(net);
 	if (retval)
@@ -2246,8 +2247,10 @@ static __net_init int nfsd_net_init(struct net *net)
 		goto out_repcache_error;
 	memset(&nn->nfsd_svcstats, 0, sizeof(nn->nfsd_svcstats));
 	nn->nfsd_svcstats.program = &nfsd_program;
-	nn->nfsd_versions = NULL;
-	nn->nfsd4_minorversions = NULL;
+	for (i = 0; i < sizeof(nn->nfsd_versions); i++)
+		nn->nfsd_versions[i] = nfsd_support_version(i);
+	for (i = 0; i < sizeof(nn->nfsd4_minorversions); i++)
+		nn->nfsd4_minorversions[i] = nfsd_support_version(4);
 	nn->nfsd_info.mutex = &nfsd_mutex;
 	nn->nfsd_serv = NULL;
 	nfsd4_init_leases_net(nn);
@@ -2278,7 +2281,6 @@ static __net_exit void nfsd_net_exit(struct net *net)
 	percpu_counter_destroy_many(nn->counter, NFSD_STATS_COUNTERS_NUM);
 	nfsd_idmap_shutdown(net);
 	nfsd_export_shutdown(net);
-	nfsd_netns_free_versions(nn);
 }
 
 static struct pernet_operations nfsd_net_ops = {

fs/nfsd/nfsd.h

@@ -23,9 +23,7 @@
 
 #include <uapi/linux/nfsd/debug.h>
 
-#include "netns.h"
 #include "export.h"
-#include "stats.h"
 
 #undef ifdebug
 #ifdef CONFIG_SUNRPC_DEBUG
@@ -37,7 +35,14 @@
 /*
  * nfsd version
  */
+#define NFSD_MINVERS			2
+#define	NFSD_MAXVERS			4
 #define NFSD_SUPPORTED_MINOR_VERSION	2
+bool nfsd_support_version(int vers);
+
+#include "netns.h"
+#include "stats.h"
+
 /*
  * Maximum blocksizes supported by daemon under various circumstances.
  */

fs/nfsd/nfssvc.c

@@ -106,7 +106,7 @@ static struct svc_program	nfsd_acl_program = {
 
 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
 
-static const struct svc_version *nfsd_version[] = {
+static const struct svc_version *nfsd_version[NFSD_MAXVERS+1] = {
 #if defined(CONFIG_NFSD_V2)
 	[2] = &nfsd_version2,
 #endif
@@ -116,15 +116,12 @@ static const struct svc_version *nfsd_version[] = {
 #endif
 };
 
-#define NFSD_MINVERS    	2
-#define NFSD_NRVERS		ARRAY_SIZE(nfsd_version)
-
 struct svc_program		nfsd_program = {
 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
 	.pg_next		= &nfsd_acl_program,
 #endif
 	.pg_prog		= NFS_PROGRAM,		/* program number */
-	.pg_nvers		= NFSD_NRVERS,		/* nr of entries in nfsd_version */
+	.pg_nvers		= NFSD_MAXVERS+1,	/* nr of entries in nfsd_version */
 	.pg_vers		= nfsd_version,		/* version table */
 	.pg_name		= "nfsd",		/* program name */
 	.pg_class		= "nfsd",		/* authentication class */
@@ -135,78 +132,24 @@ struct svc_program		nfsd_program = {
 
 bool nfsd_support_version(int vers)
 {
-	if (vers >= NFSD_MINVERS && vers < NFSD_NRVERS)
+	if (vers >= NFSD_MINVERS && vers <= NFSD_MAXVERS)
 		return nfsd_version[vers] != NULL;
 	return false;
 }
 
-static bool *
-nfsd_alloc_versions(void)
-{
-	bool *vers = kmalloc_array(NFSD_NRVERS, sizeof(bool), GFP_KERNEL);
-	unsigned i;
-
-	if (vers) {
-		/* All compiled versions are enabled by default */
-		for (i = 0; i < NFSD_NRVERS; i++)
-			vers[i] = nfsd_support_version(i);
-	}
-	return vers;
-}
-
-static bool *
-nfsd_alloc_minorversions(void)
-{
-	bool *vers = kmalloc_array(NFSD_SUPPORTED_MINOR_VERSION + 1,
-			sizeof(bool), GFP_KERNEL);
-	unsigned i;
-
-	if (vers) {
-		/* All minor versions are enabled by default */
-		for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++)
-			vers[i] = nfsd_support_version(4);
-	}
-	return vers;
-}
-
-void
-nfsd_netns_free_versions(struct nfsd_net *nn)
-{
-	kfree(nn->nfsd_versions);
-	kfree(nn->nfsd4_minorversions);
-	nn->nfsd_versions = NULL;
-	nn->nfsd4_minorversions = NULL;
-}
-
-static void
-nfsd_netns_init_versions(struct nfsd_net *nn)
-{
-	if (!nn->nfsd_versions) {
-		nn->nfsd_versions = nfsd_alloc_versions();
-		nn->nfsd4_minorversions = nfsd_alloc_minorversions();
-		if (!nn->nfsd_versions || !nn->nfsd4_minorversions)
-			nfsd_netns_free_versions(nn);
-	}
-}
-
 int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change)
 {
-	if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
+	if (vers < NFSD_MINVERS || vers > NFSD_MAXVERS)
 		return 0;
 	switch(change) {
 	case NFSD_SET:
-		if (nn->nfsd_versions)
-			nn->nfsd_versions[vers] = nfsd_support_version(vers);
+		nn->nfsd_versions[vers] = nfsd_support_version(vers);
 		break;
 	case NFSD_CLEAR:
-		nfsd_netns_init_versions(nn);
-		if (nn->nfsd_versions)
-			nn->nfsd_versions[vers] = false;
+		nn->nfsd_versions[vers] = false;
 		break;
 	case NFSD_TEST:
-		if (nn->nfsd_versions)
-			return nn->nfsd_versions[vers];
-		fallthrough;
+		return nn->nfsd_versions[vers];
 	case NFSD_AVAIL:
 		return nfsd_support_version(vers);
 	}
@@ -233,23 +176,16 @@ int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change
 
 	switch(change) {
 	case NFSD_SET:
-		if (nn->nfsd4_minorversions) {
-			nfsd_vers(nn, 4, NFSD_SET);
-			nn->nfsd4_minorversions[minorversion] =
-				nfsd_vers(nn, 4, NFSD_TEST);
-		}
+		nfsd_vers(nn, 4, NFSD_SET);
+		nn->nfsd4_minorversions[minorversion] =
+			nfsd_vers(nn, 4, NFSD_TEST);
 		break;
 	case NFSD_CLEAR:
-		nfsd_netns_init_versions(nn);
-		if (nn->nfsd4_minorversions) {
-			nn->nfsd4_minorversions[minorversion] = false;
-			nfsd_adjust_nfsd_versions4(nn);
-		}
+		nn->nfsd4_minorversions[minorversion] = false;
+		nfsd_adjust_nfsd_versions4(nn);
 		break;
 	case NFSD_TEST:
-		if (nn->nfsd4_minorversions)
-			return nn->nfsd4_minorversions[minorversion];
-		return nfsd_vers(nn, 4, NFSD_TEST);
+		return nn->nfsd4_minorversions[minorversion];
 	case NFSD_AVAIL:
 		return minorversion <= NFSD_SUPPORTED_MINOR_VERSION &&
 			nfsd_vers(nn, 4, NFSD_AVAIL);
@@ -568,11 +504,11 @@ void nfsd_reset_versions(struct nfsd_net *nn)
 {
 	int i;
 
-	for (i = 0; i < NFSD_NRVERS; i++)
+	for (i = 0; i <= NFSD_MAXVERS; i++)
 		if (nfsd_vers(nn, i, NFSD_TEST))
 			return;
 
-	for (i = 0; i < NFSD_NRVERS; i++)
+	for (i = 0; i <= NFSD_MAXVERS; i++)
 		if (i != 4)
 			nfsd_vers(nn, i, NFSD_SET);
 		else {
@@ -905,17 +841,17 @@ nfsd_init_request(struct svc_rqst *rqstp,
 	if (likely(nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST)))
 		return svc_generic_init_request(rqstp, progp, ret);
 
-	ret->mismatch.lovers = NFSD_NRVERS;
-	for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
+	ret->mismatch.lovers = NFSD_MAXVERS + 1;
+	for (i = NFSD_MINVERS; i <= NFSD_MAXVERS; i++) {
 		if (nfsd_vers(nn, i, NFSD_TEST)) {
 			ret->mismatch.lovers = i;
 			break;
 		}
 	}
-	if (ret->mismatch.lovers == NFSD_NRVERS)
+	if (ret->mismatch.lovers > NFSD_MAXVERS)
 		return rpc_prog_unavail;
 	ret->mismatch.hivers = NFSD_MINVERS;
-	for (i = NFSD_NRVERS - 1; i >= NFSD_MINVERS; i--) {
+	for (i = NFSD_MAXVERS; i >= NFSD_MINVERS; i--) {
 		if (nfsd_vers(nn, i, NFSD_TEST)) {
 			ret->mismatch.hivers = i;
 			break;