nfs41: create NFSv3 DS connection if specified

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Tom Haynes <Thomas.Haynes@primarydata.com>

3 files changed, 93 insertions, 5 deletions

diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c
index 6f340f02f2ba..48cea3c30e5d 100644
--- a/fs/nfs/nfs4super.c
+++ b/fs/nfs/nfs4super.c
@@ -346,6 +346,9 @@ out:
 
 static void __exit exit_nfs_v4(void)
 {
+        /* Not called in the _init(), conditionally loaded */
+        nfs4_pnfs_v3_ds_connect_unload();
+
         unregister_nfs_version(&nfs_v4);
         nfs4_unregister_sysctl();
         nfs_idmap_quit();
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 70ffec135696..c39882191651 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -323,9 +323,10 @@ void pnfs_generic_write_commit_done(struct rpc_task *task, void *data);
 void nfs4_pnfs_ds_put(struct nfs4_pnfs_ds *ds);
 struct nfs4_pnfs_ds *nfs4_pnfs_ds_add(struct list_head *dsaddrs,
                                       gfp_t gfp_flags);
+void nfs4_pnfs_v3_ds_connect_unload(void);
 void nfs4_pnfs_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds,
                           struct nfs4_deviceid_node *devid, unsigned int timeo,
-                          unsigned int retrans, u32 versoin, u32 minor_version,
+                          unsigned int retrans, u32 version, u32 minor_version,
                           rpc_authflavor_t au_flavor);
 struct nfs4_pnfs_ds_addr *nfs4_decode_mp_ds_addr(struct net *net,
                                                  struct xdr_stream *xdr,
@@ -615,6 +616,10 @@ static inline struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
         return NULL;
 }
 
+static inline void nfs4_pnfs_v3_ds_connect_unload(void)
+{
+}
+
 #endif /* CONFIG_NFS_V4_1 */
 
 #endif /* FS_NFS_PNFS_H */
diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c
index ad211a4e1874..23c851d4c9a9 100644
--- a/fs/nfs/pnfs_nfs.c
+++ b/fs/nfs/pnfs_nfs.c
@@ -10,6 +10,7 @@
 #include <linux/nfs_fs.h>
 #include <linux/nfs_page.h>
 #include <linux/sunrpc/addr.h>
+#include <linux/module.h>
 
 #include "nfs4session.h"
 #include "internal.h"
@@ -550,7 +551,75 @@ static void nfs4_clear_ds_conn_bit(struct nfs4_pnfs_ds *ds)
         wake_up_bit(&ds->ds_state, NFS4DS_CONNECTING);
 }
 
-static int _nfs4_pnfs_ds_connect(struct nfs_server *mds_srv,
+static struct nfs_client *(*get_v3_ds_connect)(
+                        struct nfs_client *mds_clp,
+                        const struct sockaddr *ds_addr,
+                        int ds_addrlen,
+                        int ds_proto,
+                        unsigned int ds_timeo,
+                        unsigned int ds_retrans,
+                        rpc_authflavor_t au_flavor);
+
+static bool load_v3_ds_connect(void)
+{
+        if (!get_v3_ds_connect) {
+                get_v3_ds_connect = symbol_request(nfs3_set_ds_client);
+                WARN_ON_ONCE(!get_v3_ds_connect);
+        }
+
+        return(get_v3_ds_connect != NULL);
+}
+
+void __exit nfs4_pnfs_v3_ds_connect_unload(void)
+{
+        if (get_v3_ds_connect) {
+                symbol_put(nfs3_set_ds_client);
+                get_v3_ds_connect = NULL;
+        }
+}
+EXPORT_SYMBOL_GPL(nfs4_pnfs_v3_ds_connect_unload);
+
+static int _nfs4_pnfs_v3_ds_connect(struct nfs_server *mds_srv,
+                                 struct nfs4_pnfs_ds *ds,
+                                 unsigned int timeo,
+                                 unsigned int retrans,
+                                 rpc_authflavor_t au_flavor)
+{
+        struct nfs_client *clp = ERR_PTR(-EIO);
+        struct nfs4_pnfs_ds_addr *da;
+        int status = 0;
+
+        dprintk("--> %s DS %s au_flavor %d\n", __func__,
+                ds->ds_remotestr, au_flavor);
+
+        if (!load_v3_ds_connect())
+                goto out;
+
+        list_for_each_entry(da, &ds->ds_addrs, da_node) {
+                dprintk("%s: DS %s: trying address %s\n",
+                        __func__, ds->ds_remotestr, da->da_remotestr);
+
+                clp = get_v3_ds_connect(mds_srv->nfs_client,
+                                        (struct sockaddr *)&da->da_addr,
+                                        da->da_addrlen, IPPROTO_TCP,
+                                        timeo, retrans, au_flavor);
+                if (!IS_ERR(clp))
+                        break;
+        }
+
+        if (IS_ERR(clp)) {
+                status = PTR_ERR(clp);
+                goto out;
+        }
+
+        smp_wmb();
+        ds->ds_clp = clp;
+        dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
+out:
+        return status;
+}
+
+static int _nfs4_pnfs_v4_ds_connect(struct nfs_server *mds_srv,
                                  struct nfs4_pnfs_ds *ds,
                                  unsigned int timeo,
                                  unsigned int retrans,
@@ -562,7 +631,7 @@ static int _nfs4_pnfs_ds_connect(struct nfs_server *mds_srv,
         int status = 0;
 
         dprintk("--> %s DS %s au_flavor %d\n", __func__, ds->ds_remotestr,
-                mds_srv->nfs_client->cl_rpcclient->cl_auth->au_flavor);
+                au_flavor);
 
         list_for_each_entry(da, &ds->ds_addrs, da_node) {
                 dprintk("%s: DS %s: trying address %s\n",
@@ -609,8 +678,19 @@ void nfs4_pnfs_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds,
         if (test_and_set_bit(NFS4DS_CONNECTING, &ds->ds_state) == 0) {
                 int err = 0;
 
-                err = _nfs4_pnfs_ds_connect(mds_srv, ds, timeo, retrans,
-                                            minor_version, au_flavor);
+                if (version == 3) {
+                        err = _nfs4_pnfs_v3_ds_connect(mds_srv, ds, timeo,
+                                                       retrans, au_flavor);
+                } else if (version == 4) {
+                        err = _nfs4_pnfs_v4_ds_connect(mds_srv, ds, timeo,
+                                                       retrans, minor_version,
+                                                       au_flavor);
+                } else {
+                        dprintk("%s: unsupported DS version %d\n", __func__,
+                                version);
+                        err = -EPROTONOSUPPORT;
+                }
+
                 if (err)
                         nfs4_mark_deviceid_unavailable(devid);
                 nfs4_clear_ds_conn_bit(ds);