GFS2: Fix glock ref counting bug

Depending on the ordering of events as we go around the
glock shrinker loop, it is possible to drop the ref count
of a glock incorrectly. It doesn't happen very often. This
patch corrects the got_ref variable, fixing the problem.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 1afd9f2..ff49810 100644 (file)
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1304,6 +1304,7 @@ static int gfs2_shrink_glock_memory(int nr, gfp_t gfp_mask)
                                nr--;
                                if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
                                        gfs2_glock_put(gl);
+                               got_ref = 0;
                        }
                        spin_lock(&lru_lock);
                        if (may_demote)