nfsd: Allow containers to set supported nfs versions

Support use of the --nfs-version/--no-nfs-version arguments to rpc.nfsd
in containers.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

5 files changed, 197 insertions, 61 deletions

diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index b42aaa22fba2..789abc4dd1d2 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -134,10 +134,18 @@ struct nfsd_net {
         u32             s2s_cp_cl_id;
         struct idr      s2s_cp_stateids;
         spinlock_t      s2s_cp_lock;
+
+        /*
+         * Version information
+         */
+        bool *nfsd_versions;
+        bool *nfsd4_minorversions;
 };
 
 /* Simple check to find out if a given net was properly initialized */
 #define nfsd_netns_ready(nn) ((nn)->sessionid_hashtbl)
 
+extern void nfsd_netns_free_versions(struct nfsd_net *nn);
+
 extern unsigned int nfsd_net_id;
 #endif /* __NFSD_NETNS_H__ */
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 0cfd257ffdaf..b0ad72d701b1 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1926,6 +1926,7 @@ nfsd4_proc_compound(struct svc_rqst *rqstp)
         struct nfsd4_compound_state *cstate = &resp->cstate;
         struct svc_fh *current_fh = &cstate->current_fh;
         struct svc_fh *save_fh = &cstate->save_fh;
+        struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
         __be32          status;
 
         svcxdr_init_encode(rqstp, resp);
@@ -1948,7 +1949,7 @@ nfsd4_proc_compound(struct svc_rqst *rqstp)
          * According to RFC3010, this takes precedence over all other errors.
          */
         status = nfserr_minor_vers_mismatch;
-        if (nfsd_minorversion(args->minorversion, NFSD_TEST) <= 0)
+        if (nfsd_minorversion(nn, args->minorversion, NFSD_TEST) <= 0)
                 goto out;
         status = nfserr_resource;
         if (args->opcnt > NFSD_MAX_OPS_PER_COMPOUND)
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 6667d3a4f839..630d629090be 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -537,14 +537,14 @@ out_free:
 }
 
 static ssize_t
-nfsd_print_version_support(char *buf, int remaining, const char *sep,
-                unsigned vers, int minor)
+nfsd_print_version_support(struct nfsd_net *nn, char *buf, int remaining,
+                const char *sep, unsigned vers, int minor)
 {
         const char *format = minor < 0 ? "%s%c%u" : "%s%c%u.%u";
-        bool supported = !!nfsd_vers(vers, NFSD_TEST);
+        bool supported = !!nfsd_vers(nn, vers, NFSD_TEST);
 
         if (vers == 4 && minor >= 0 &&
-            !nfsd_minorversion(minor, NFSD_TEST))
+            !nfsd_minorversion(nn, minor, NFSD_TEST))
                 supported = false;
         if (minor == 0 && supported)
                 /*
@@ -599,20 +599,20 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size)
                         switch(num) {
                         case 2:
                         case 3:
-                                nfsd_vers(num, cmd);
+                                nfsd_vers(nn, num, cmd);
                                 break;
                         case 4:
                                 if (*minorp == '.') {
-                                        if (nfsd_minorversion(minor, cmd) < 0)
+                                        if (nfsd_minorversion(nn, minor, cmd) < 0)
                                                 return -EINVAL;
-                                } else if ((cmd == NFSD_SET) != nfsd_vers(num, NFSD_TEST)) {
+                                } else if ((cmd == NFSD_SET) != nfsd_vers(nn, num, NFSD_TEST)) {
                                         /*
                                          * Either we have +4 and no minors are enabled,
                                          * or we have -4 and at least one minor is enabled.
                                          * In either case, propagate 'cmd' to all minors.
                                          */
                                         minor = 0;
-                                        while (nfsd_minorversion(minor, cmd) >= 0)
+                                        while (nfsd_minorversion(nn, minor, cmd) >= 0)
                                                 minor++;
                                 }
                                 break;
@@ -624,7 +624,7 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size)
                 /* If all get turned off, turn them back on, as
                  * having no versions is BAD
                  */
-                nfsd_reset_versions();
+                nfsd_reset_versions(nn);
         }
 
         /* Now write current state into reply buffer */
@@ -633,12 +633,12 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size)
         remaining = SIMPLE_TRANSACTION_LIMIT;
         for (num=2 ; num <= 4 ; num++) {
                 int minor;
-                if (!nfsd_vers(num, NFSD_AVAIL))
+                if (!nfsd_vers(nn, num, NFSD_AVAIL))
                         continue;
 
                 minor = -1;
                 do {
-                        len = nfsd_print_version_support(buf, remaining,
+                        len = nfsd_print_version_support(nn, buf, remaining,
                                         sep, num, minor);
                         if (len >= remaining)
                                 goto out;
@@ -1239,6 +1239,8 @@ static __net_init int nfsd_init_net(struct net *net)
         retval = nfsd_idmap_init(net);
         if (retval)
                 goto out_idmap_error;
+        nn->nfsd_versions = NULL;
+        nn->nfsd4_minorversions = NULL;
         nn->nfsd4_lease = 90;   /* default lease time */
         nn->nfsd4_grace = 90;
         nn->somebody_reclaimed = false;
@@ -1261,6 +1263,7 @@ static __net_exit void nfsd_exit_net(struct net *net)
 {
         nfsd_idmap_shutdown(net);
         nfsd_export_shutdown(net);
+        nfsd_netns_free_versions(net_generic(net, nfsd_net_id));
 }
 
 static struct pernet_operations nfsd_net_ops = {
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index 066899929863..6bae2554b2b2 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -98,10 +98,12 @@ extern const struct svc_version nfsd_acl_version3;
 #endif
 #endif
 
+struct nfsd_net;
+
 enum vers_op {NFSD_SET, NFSD_CLEAR, NFSD_TEST, NFSD_AVAIL };
-int nfsd_vers(int vers, enum vers_op change);
-int nfsd_minorversion(u32 minorversion, enum vers_op change);
-void nfsd_reset_versions(void);
+int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change);
+int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change);
+void nfsd_reset_versions(struct nfsd_net *nn);
 int nfsd_create_serv(struct net *net);
 
 extern int nfsd_max_blksize;
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 378edcfe9701..520757774614 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -38,12 +38,18 @@ static int			nfsd_acl_rpcbind_set(struct net *,
                                                      u32, int,
                                                      unsigned short,
                                                      unsigned short);
+static __be32                   nfsd_acl_init_request(struct svc_rqst *,
+                                                const struct svc_program *,
+                                                struct svc_process_info *);
 #endif
 static int                      nfsd_rpcbind_set(struct net *,
                                                  const struct svc_program *,
                                                  u32, int,
                                                  unsigned short,
                                                  unsigned short);
+static __be32                   nfsd_init_request(struct svc_rqst *,
+                                                const struct svc_program *,
+                                                struct svc_process_info *);
 
 /*
  * nfsd_mutex protects nn->nfsd_serv -- both the pointer itself and the members
@@ -98,7 +104,7 @@ static struct svc_program	nfsd_acl_program = {
         .pg_class               = "nfsd",
         .pg_stats               = &nfsd_acl_svcstats,
         .pg_authenticate        = &svc_set_client,
-        .pg_init_request        = svc_generic_init_request,
+        .pg_init_request        = nfsd_acl_init_request,
         .pg_rpcbind_set         = nfsd_acl_rpcbind_set,
 };
 
@@ -119,7 +125,6 @@ static const struct svc_version *nfsd_version[] = {
 
 #define NFSD_MINVERS            2
 #define NFSD_NRVERS             ARRAY_SIZE(nfsd_version)
-static const struct svc_version *nfsd_versions[NFSD_NRVERS];
 
 struct svc_program              nfsd_program = {
 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
@@ -127,78 +132,136 @@ struct svc_program		nfsd_program = {
 #endif
         .pg_prog                = NFS_PROGRAM,          /* program number */
         .pg_nvers               = NFSD_NRVERS,          /* nr of entries in nfsd_version */
-        .pg_vers                = nfsd_versions,        /* version table */
+        .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 */
-        .pg_init_request        = svc_generic_init_request,
+        .pg_init_request        = nfsd_init_request,
         .pg_rpcbind_set         = nfsd_rpcbind_set,
 };
 
-static bool nfsd_supported_minorversions[NFSD_SUPPORTED_MINOR_VERSION + 1] = {
-        [0] = 1,
-        [1] = 1,
-        [2] = 1,
-};
+static bool
+nfsd_support_version(int vers)
+{
+        if (vers >= NFSD_MINVERS && vers < NFSD_NRVERS)
+                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;
 
-int nfsd_vers(int vers, enum vers_op change)
+        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)
                 return 0;
         switch(change) {
         case NFSD_SET:
-                nfsd_versions[vers] = nfsd_version[vers];
-#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
-                if (vers < NFSD_ACL_NRVERS)
-                        nfsd_acl_versions[vers] = nfsd_acl_version[vers];
-#endif
+                if (nn->nfsd_versions)
+                        nn->nfsd_versions[vers] = nfsd_support_version(vers);
                 break;
         case NFSD_CLEAR:
-                nfsd_versions[vers] = NULL;
-#if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
-                if (vers < NFSD_ACL_NRVERS)
-                        nfsd_acl_versions[vers] = NULL;
-#endif
+                nfsd_netns_init_versions(nn);
+                if (nn->nfsd_versions)
+                        nn->nfsd_versions[vers] = false;
                 break;
         case NFSD_TEST:
-                return nfsd_versions[vers] != NULL;
+                if (nn->nfsd_versions)
+                        return nn->nfsd_versions[vers];
+                /* Fallthrough */
         case NFSD_AVAIL:
-                return nfsd_version[vers] != NULL;
+                return nfsd_support_version(vers);
         }
         return 0;
 }
 
 static void
-nfsd_adjust_nfsd_versions4(void)
+nfsd_adjust_nfsd_versions4(struct nfsd_net *nn)
 {
         unsigned i;
 
         for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) {
-                if (nfsd_supported_minorversions[i])
+                if (nn->nfsd4_minorversions[i])
                         return;
         }
-        nfsd_vers(4, NFSD_CLEAR);
+        nfsd_vers(nn, 4, NFSD_CLEAR);
 }
 
-int nfsd_minorversion(u32 minorversion, enum vers_op change)
+int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change)
 {
         if (minorversion > NFSD_SUPPORTED_MINOR_VERSION &&
             change != NFSD_AVAIL)
                 return -1;
+
         switch(change) {
         case NFSD_SET:
-                nfsd_supported_minorversions[minorversion] = true;
-                nfsd_vers(4, NFSD_SET);
+                if (nn->nfsd4_minorversions) {
+                        nfsd_vers(nn, 4, NFSD_SET);
+                        nn->nfsd4_minorversions[minorversion] =
+                                nfsd_vers(nn, 4, NFSD_TEST);
+                }
                 break;
         case NFSD_CLEAR:
-                nfsd_supported_minorversions[minorversion] = false;
-                nfsd_adjust_nfsd_versions4();
+                nfsd_netns_init_versions(nn);
+                if (nn->nfsd4_minorversions) {
+                        nn->nfsd4_minorversions[minorversion] = false;
+                        nfsd_adjust_nfsd_versions4(nn);
+                }
                 break;
         case NFSD_TEST:
-                return nfsd_supported_minorversions[minorversion];
+                if (nn->nfsd4_minorversions)
+                        return nn->nfsd4_minorversions[minorversion];
+                return nfsd_vers(nn, 4, NFSD_TEST);
         case NFSD_AVAIL:
-                return minorversion <= NFSD_SUPPORTED_MINOR_VERSION;
+                return minorversion <= NFSD_SUPPORTED_MINOR_VERSION &&
+                        nfsd_vers(nn, 4, NFSD_AVAIL);
         }
         return 0;
 }
@@ -280,13 +343,9 @@ static void nfsd_shutdown_generic(void)
         nfsd_racache_shutdown();
 }
 
-static bool nfsd_needs_lockd(void)
+static bool nfsd_needs_lockd(struct nfsd_net *nn)
 {
-#if defined(CONFIG_NFSD_V3)
-        return (nfsd_versions[2] != NULL) || (nfsd_versions[3] != NULL);
-#else
-        return (nfsd_versions[2] != NULL);
-#endif
+        return nfsd_vers(nn, 2, NFSD_TEST) || nfsd_vers(nn, 3, NFSD_TEST);
 }
 
 static int nfsd_startup_net(int nrservs, struct net *net)
@@ -304,7 +363,7 @@ static int nfsd_startup_net(int nrservs, struct net *net)
         if (ret)
                 goto out_socks;
 
-        if (nfsd_needs_lockd() && !nn->lockd_up) {
+        if (nfsd_needs_lockd(nn) && !nn->lockd_up) {
                 ret = lockd_up(net);
                 if (ret)
                         goto out_socks;
@@ -437,20 +496,20 @@ static void nfsd_last_thread(struct svc_serv *serv, struct net *net)
         nfsd_export_flush(net);
 }
 
-void nfsd_reset_versions(void)
+void nfsd_reset_versions(struct nfsd_net *nn)
 {
         int i;
 
         for (i = 0; i < NFSD_NRVERS; i++)
-                if (nfsd_vers(i, NFSD_TEST))
+                if (nfsd_vers(nn, i, NFSD_TEST))
                         return;
 
         for (i = 0; i < NFSD_NRVERS; i++)
                 if (i != 4)
-                        nfsd_vers(i, NFSD_SET);
+                        nfsd_vers(nn, i, NFSD_SET);
                 else {
                         int minor = 0;
-                        while (nfsd_minorversion(minor, NFSD_SET) >= 0)
+                        while (nfsd_minorversion(nn, minor, NFSD_SET) >= 0)
                                 minor++;
                 }
 }
@@ -518,7 +577,7 @@ int nfsd_create_serv(struct net *net)
         }
         if (nfsd_max_blksize == 0)
                 nfsd_max_blksize = nfsd_get_default_max_blksize();
-        nfsd_reset_versions();
+        nfsd_reset_versions(nn);
         nn->nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize,
                                                 &nfsd_thread_sv_ops);
         if (nn->nfsd_serv == NULL)
@@ -697,11 +756,44 @@ nfsd_acl_rpcbind_set(struct net *net, const struct svc_program *progp,
                      unsigned short port)
 {
         if (!nfsd_support_acl_version(version) ||
-            !nfsd_vers(version, NFSD_TEST))
+            !nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST))
                 return 0;
         return svc_generic_rpcbind_set(net, progp, version, family,
                         proto, port);
 }
+
+static __be32
+nfsd_acl_init_request(struct svc_rqst *rqstp,
+                      const struct svc_program *progp,
+                      struct svc_process_info *ret)
+{
+        struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+        int i;
+
+        if (likely(nfsd_support_acl_version(rqstp->rq_vers) &&
+            nfsd_vers(nn, rqstp->rq_vers, NFSD_TEST)))
+                return svc_generic_init_request(rqstp, progp, ret);
+
+        ret->mismatch.lovers = NFSD_ACL_NRVERS;
+        for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++) {
+                if (nfsd_support_acl_version(rqstp->rq_vers) &&
+                    nfsd_vers(nn, i, NFSD_TEST)) {
+                        ret->mismatch.lovers = i;
+                        break;
+                }
+        }
+        if (ret->mismatch.lovers == NFSD_ACL_NRVERS)
+                return rpc_prog_unavail;
+        ret->mismatch.hivers = NFSD_ACL_MINVERS;
+        for (i = NFSD_ACL_NRVERS - 1; i >= NFSD_ACL_MINVERS; i--) {
+                if (nfsd_support_acl_version(rqstp->rq_vers) &&
+                    nfsd_vers(nn, i, NFSD_TEST)) {
+                        ret->mismatch.hivers = i;
+                        break;
+                }
+        }
+        return rpc_prog_mismatch;
+}
 #endif
 
 static int
@@ -709,12 +801,42 @@ nfsd_rpcbind_set(struct net *net, const struct svc_program *progp,
                  u32 version, int family, unsigned short proto,
                  unsigned short port)
 {
-        if (!nfsd_vers(version, NFSD_TEST))
+        if (!nfsd_vers(net_generic(net, nfsd_net_id), version, NFSD_TEST))
                 return 0;
         return svc_generic_rpcbind_set(net, progp, version, family,
                         proto, port);
 }
 
+static __be32
+nfsd_init_request(struct svc_rqst *rqstp,
+                  const struct svc_program *progp,
+                  struct svc_process_info *ret)
+{
+        struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+        int i;
+
+        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++) {
+                if (nfsd_vers(nn, i, NFSD_TEST)) {
+                        ret->mismatch.lovers = i;
+                        break;
+                }
+        }
+        if (ret->mismatch.lovers == NFSD_NRVERS)
+                return rpc_prog_unavail;
+        ret->mismatch.hivers = NFSD_MINVERS;
+        for (i = NFSD_NRVERS - 1; i >= NFSD_MINVERS; i--) {
+                if (nfsd_vers(nn, i, NFSD_TEST)) {
+                        ret->mismatch.hivers = i;
+                        break;
+                }
+        }
+        return rpc_prog_mismatch;
+}
+
 /*
  * This is the NFS server kernel thread
  */