NFSv4: Introduce new label structure

In order to mimic the way that NFSv4 ACLs are implemented we have created a
structure to be used to pass label data up and down the call chain. This patch
adds the new structure and new members to the required NFSv4 call structures.

Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: Miguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index c1c7a9d78722..07fcf0b90669 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -257,6 +257,34 @@ nfs_init_locked(struct inode *inode, void *opaque)
         return 0;
 }
 
+#ifdef CONFIG_NFS_V4_SECURITY_LABEL
+struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags)
+{
+        struct nfs4_label *label = NULL;
+        int minor_version = server->nfs_client->cl_minorversion;
+
+        if (minor_version < 2)
+                return label;
+
+        if (!(server->caps & NFS_CAP_SECURITY_LABEL))
+                return label;
+
+        label = kzalloc(sizeof(struct nfs4_label), flags);
+        if (label == NULL)
+                return ERR_PTR(-ENOMEM);
+
+        label->label = kzalloc(NFS4_MAXLABELLEN, flags);
+        if (label->label == NULL) {
+                kfree(label);
+                return ERR_PTR(-ENOMEM);
+        }
+        label->len = NFS4_MAXLABELLEN;
+
+        return label;
+}
+EXPORT_SYMBOL_GPL(nfs4_label_alloc);
+#endif
+
 /*
  * This is our front-end to iget that looks up inodes by file handle
  * instead of inode number.