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>

1 files changed, 19 insertions, 83 deletions

diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index f25b26bc5670..5bc4dc60ea4c 100644
--- a/fs/nfsd/nfssvc.c
+++ b/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;