NFS: Add a mount option to specify number of TCP connections to use

Allow the user to specify that the client should use multiple connections
to the server. For the moment, this functionality will be limited to
TCP and to NFSv4.x (x>0).

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

2 files changed, 11 insertions, 0 deletions

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 498fab72f70b..bba09dace5d6 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -123,6 +123,7 @@ struct nfs_parsed_mount_data {
                 char                    *export_path;
                 int                     port;
                 unsigned short          protocol;
+                unsigned short          nconnect;
         } nfs_server;
 
         void                    *lsm_opts;
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index f88ddac2dcdf..68ad0b8bcabd 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -77,6 +77,8 @@
 #define NFS_DEFAULT_VERSION 2
 #endif
 
+#define NFS_MAX_CONNECTIONS 16
+
 enum {
         /* Mount options that take no arguments */
         Opt_soft, Opt_softerr, Opt_hard,
@@ -108,6 +110,7 @@ enum {
         Opt_nfsvers,
         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
         Opt_addr, Opt_mountaddr, Opt_clientaddr,
+        Opt_nconnect,
         Opt_lookupcache,
         Opt_fscache_uniq,
         Opt_local_lock,
@@ -181,6 +184,8 @@ static const match_table_t nfs_mount_option_tokens = {
         { Opt_mounthost, "mounthost=%s" },
         { Opt_mountaddr, "mountaddr=%s" },
 
+        { Opt_nconnect, "nconnect=%s" },
+
         { Opt_lookupcache, "lookupcache=%s" },
         { Opt_fscache_uniq, "fsc=%s" },
         { Opt_local_lock, "local_lock=%s" },
@@ -1549,6 +1554,11 @@ static int nfs_parse_mount_options(char *raw,
                         if (mnt->mount_server.addrlen == 0)
                                 goto out_invalid_address;
                         break;
+                case Opt_nconnect:
+                        if (nfs_get_option_ul_bound(args, &option, 1, NFS_MAX_CONNECTIONS))
+                                goto out_invalid_value;
+                        mnt->nfs_server.nconnect = option;
+                        break;
                 case Opt_lookupcache:
                         string = match_strdup(args);
                         if (string == NULL)