NFS: use secinfo when crossing mountpoints

A submount may use different security than the parent
mount does.  We should figure out what sec flavor the
submount uses at mount time.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 0b8bae119976..563463777d9d 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -87,6 +87,8 @@ static int nfs4_map_errors(int err)
         switch (err) {
         case -NFS4ERR_RESOURCE:
                 return -EREMOTEIO;
+        case -NFS4ERR_WRONGSEC:
+                return -EPERM;
         case -NFS4ERR_BADOWNER:
         case -NFS4ERR_BADNAME:
                 return -EINVAL;
@@ -2383,6 +2385,16 @@ static int _nfs4_proc_lookup(struct rpc_clnt *clnt, struct inode *dir,
         return status;
 }
 
+void nfs_fixup_secinfo_attributes(struct nfs_fattr *fattr, struct nfs_fh *fh)
+{
+        memset(fh, 0, sizeof(struct nfs_fh));
+        fattr->fsid.major = 1;
+        fattr->valid |= NFS_ATTR_FATTR_TYPE | NFS_ATTR_FATTR_MODE |
+                NFS_ATTR_FATTR_NLINK | NFS_ATTR_FATTR_FSID | NFS_ATTR_FATTR_MOUNTPOINT;
+        fattr->mode = S_IFDIR | S_IRUGO | S_IXUGO;
+        fattr->nlink = 2;
+}
+
 static int nfs4_proc_lookup(struct rpc_clnt *clnt, struct inode *dir, struct qstr *name,
                             struct nfs_fh *fhandle, struct nfs_fattr *fattr)
 {
@@ -2392,6 +2404,8 @@ static int nfs4_proc_lookup(struct rpc_clnt *clnt, struct inode *dir, struct qst
                 err = nfs4_handle_exception(NFS_SERVER(dir),
                                 _nfs4_proc_lookup(clnt, dir, name, fhandle, fattr),
                                 &exception);
+                if (err == -EPERM)
+                        nfs_fixup_secinfo_attributes(fattr, fhandle);
         } while (exception.retry);
         return err;
 }