dlm: avoid scanning unchanged toss lists

Keep track of whether a toss list contains any
shrinkable rsbs.  If not, dlm_scand can avoid
scanning the list for rsbs to shrink.  Unnecessary
scanning can otherwise waste a lot of time because
the toss lists can contain a large number of rsbs
that are non-shrinkable (directory records).

Signed-off-by: David Teigland <teigland@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index 77c0f70..e7665c3 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -96,10 +96,13 @@ do { \
 }
 
 
+#define DLM_RTF_SHRINK		0x00000001
+
 struct dlm_rsbtable {
 	struct rb_root		keep;
 	struct rb_root		toss;
 	spinlock_t		lock;
+	uint32_t		flags;
 };