[SMB3] Fix oops when creating symlinks on smb3

We were not checking for symlink support properly for SMB2/SMB3
mounts so could oops when mounted with mfsymlinks when try
to create symlink when mfsymlinks on smb2/smb3 mounts

Signed-off-by: Steve French <smfrench@gmail.com>
Cc: <stable@vger.kernel.org> # 3.14+
CC: Sachin Prabhu <sprabhu@redhat.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 68559fd557fb..a5c2812ead68 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -213,8 +213,12 @@ create_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
         if (rc)
                 goto out;
 
-        rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon, cifs_sb,
-                                        fromName, buf, &bytes_written);
+        if (tcon->ses->server->ops->create_mf_symlink)
+                rc = tcon->ses->server->ops->create_mf_symlink(xid, tcon,
+                                        cifs_sb, fromName, buf, &bytes_written);
+        else
+                rc = -EOPNOTSUPP;
+
         if (rc)
                 goto out;