re: SUNRPC: Convert auth_gss pipe detection to work in namespaces

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello Trond Myklebust,

The patch 11575f2498f5: "SUNRPC: Convert auth_gss pipe detection to
work in namespaces" from May 15, 2013, leads to the following Smatch
warnings:

net/sunrpc/auth_gss/auth_gss.c:275 get_pipe_version() warn: always true condition '(sn->pipe_version >= 0) => (0-u32max >= 0)'"
net/sunrpc/auth_gss/auth_gss.c:732 gss_pipe_open() warn: unsigned 'sn->pipe_version' is never less than zero.
net/sunrpc/auth_gss/auth_gss.c:590 gss_create_upcall() warn: unsigned 'sn->pipe_version' is never less than zero.

net/sunrpc/auth_gss/auth_gss.c
   274          spin_lock(&pipe_version_lock);
>  275          if (sn->pipe_version >= 0) {
   276                  atomic_inc(&sn->pipe_users);
   277                  ret = sn->pipe_version;
   278          } else
   279                  ret = -EAGAIN;

[snip]

>  590                  if (sn->pipe_version < 0) {
   591                          if (err == 0)
   592                                  sn->gssd_running = 0;
   593                          warn_gssd();
   594                          err = -EACCES;
   595                  }
   596                  if (err < 0)
   597                          goto out;

[snip]

   731          spin_lock(&pipe_version_lock);
>  732          if (sn->pipe_version < 0) {
   733                  /* First open of any gss pipe determines the version: */
   734                  sn->pipe_version = new_version;
   735                  rpc_wake_up(&pipe_version_rpc_waitqueue);
   736                  wake_up(&pipe_version_waitqueue);
   737          } else if (sn->pipe_version != new_version) {
   738                  /* Trying to open a pipe of a different version */
   739                  ret = -EBUSY;
   740                  goto out;
   741          }

regards,
dan carpenter