[PATCH] knfsd: Allow run-time selection of NFS versions to export

Provide a file in the NFSD filesystem that allows setting and querying of
which version of NFS are being exported.  Changes are only allowed while no
server is running.

Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 51 insertions, 28 deletions

diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 1697539a7171..0568ff8565b1 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -30,6 +30,7 @@
 #include <linux/nfsd/nfsd.h>
 #include <linux/nfsd/stats.h>
 #include <linux/nfsd/cache.h>
+#include <linux/nfsd/syscall.h>
 #include <linux/lockd/bind.h>
 #include <linux/nfsacl.h>
 
@@ -52,7 +53,7 @@
 extern struct svc_program       nfsd_program;
 static void                     nfsd(struct svc_rqst *rqstp);
 struct timeval                  nfssvc_boot;
-static struct svc_serv          *nfsd_serv;
+       struct svc_serv          *nfsd_serv;
 static atomic_t                 nfsd_busy;
 static unsigned long            nfsd_last_call;
 static DEFINE_SPINLOCK(nfsd_call_lock);
@@ -63,6 +64,31 @@ struct nfsd_list {
 };
 static struct list_head nfsd_list = LIST_HEAD_INIT(nfsd_list);
 
+static struct svc_version *     nfsd_version[] = {
+        [2] = &nfsd_version2,
+#if defined(CONFIG_NFSD_V3)
+        [3] = &nfsd_version3,
+#endif
+#if defined(CONFIG_NFSD_V4)
+        [4] = &nfsd_version4,
+#endif
+};
+
+#define NFSD_MINVERS            2
+#define NFSD_NRVERS             (sizeof(nfsd_version)/sizeof(nfsd_version[0]))
+static struct svc_version *nfsd_versions[NFSD_NRVERS];
+
+struct svc_program              nfsd_program = {
+        .pg_prog                = NFS_PROGRAM,          /* program number */
+        .pg_nvers               = NFSD_NRVERS,          /* nr of entries in nfsd_version */
+        .pg_vers                = nfsd_versions,        /* version table */
+        .pg_name                = "nfsd",               /* program name */
+        .pg_class               = "nfsd",               /* authentication class */
+        .pg_stats               = &nfsd_svcstats,       /* version table */
+        .pg_authenticate        = &svc_set_client,      /* export authentication */
+
+};
+
 /*
  * Maximum number of nfsd processes
  */
@@ -80,11 +106,12 @@ int
 nfsd_svc(unsigned short port, int nrservs)
 {
         int     error;
-        int     none_left;      
+        int     none_left, found_one, i;
         struct list_head *victim;
         
         lock_kernel();
-        dprintk("nfsd: creating service\n");
+        dprintk("nfsd: creating service: vers 0x%x\n",
+                nfsd_versbits);
         error = -EINVAL;
         if (nrservs <= 0)
                 nrservs = 0;
@@ -99,6 +126,27 @@ nfsd_svc(unsigned short port, int nrservs)
         if (error<0)
                 goto out;
         if (!nfsd_serv) {
+                /*
+                 * Use the nfsd_ctlbits to define which
+                 * versions that will be advertised.
+                 * If nfsd_ctlbits doesn't list any version,
+                 * export them all.
+                 */
+                found_one = 0;
+
+                for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
+                        if (NFSCTL_VERISSET(nfsd_versbits, i)) {
+                                nfsd_program.pg_vers[i] = nfsd_version[i];
+                                found_one = 1;
+                        } else
+                                nfsd_program.pg_vers[i] = NULL;
+                }
+
+                if (!found_one) {
+                        for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++)
+                                nfsd_program.pg_vers[i] = nfsd_version[i];
+                }
+
                 atomic_set(&nfsd_busy, 0);
                 error = -ENOMEM;
                 nfsd_serv = svc_create(&nfsd_program, NFSD_BUFSIZE);
@@ -389,28 +437,3 @@ static struct svc_stat	nfsd_acl_svcstats = {
 #else
 #define nfsd_acl_program_p      NULL
 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
-
-extern struct svc_version nfsd_version2, nfsd_version3, nfsd_version4;
-
-static struct svc_version *     nfsd_version[] = {
-        [2] = &nfsd_version2,
-#if defined(CONFIG_NFSD_V3)
-        [3] = &nfsd_version3,
-#endif
-#if defined(CONFIG_NFSD_V4)
-        [4] = &nfsd_version4,
-#endif
-};
-
-#define NFSD_NRVERS             (sizeof(nfsd_version)/sizeof(nfsd_version[0]))
-struct svc_program              nfsd_program = {
-        .pg_next                = nfsd_acl_program_p,
-        .pg_prog                = NFS_PROGRAM,          /* program number */
-        .pg_nvers               = NFSD_NRVERS,          /* nr of entries in nfsd_version */
-        .pg_vers                = nfsd_version,         /* version table */
-        .pg_name                = "nfsd",               /* program name */
-        .pg_class               = "nfsd",               /* authentication class */
-        .pg_stats               = &nfsd_svcstats,       /* version table */
-        .pg_authenticate        = &svc_set_client,      /* export authentication */
-
-};