[Cluster-devel] [bug report] GFS2: Use resizable hash table for glocks

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

Hello Bob Peterson,

The patch 88ffbf3e037e: "GFS2: Use resizable hash table for glocks"
from Mar 16, 2015, leads to the following static checker warning:

	fs/gfs2/glock.c:1813 gfs2_glock_iter_next()
	error: 'gi->gl' dereferencing possible ERR_PTR()

fs/gfs2/glock.c
  1803  static void gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
  1804  {
  1805          do {
  1806                  gi->gl = rhashtable_walk_next(&gi->hti);
  1807                  if (IS_ERR(gi->gl)) {
  1808                          if (PTR_ERR(gi->gl) == -EAGAIN)
  1809                                  continue;

This continue was probably intended to go to the top of the loop, but
it's a do while loop so it actually drops down

  1810                          gi->gl = NULL;
  1811                  }
  1812          /* Skip entries for other sb and dead entries */
  1813          } while ((gi->gl) && ((gi->sdp != gi->gl->gl_name.ln_sbd) ||
                                                  ^^^^^^^^
to here where we dereference gi->gl.  It's weird that Smatch is only
complaining about this now though...

  1814                                __lockref_is_dead(&gi->gl->gl_lockref)));
  1815  }

regards,
dan carpenter