dlm: convert rsb list to rb_tree

Change the linked lists to rb_tree's in the rsb
hash table to speed up searches.  Slow rsb searches
were having a large impact on gfs2 performance due
to the large number of dlm locks gfs2 uses.

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

1 files changed, 13 insertions, 8 deletions

diff --git a/fs/dlm/recover.c b/fs/dlm/recover.c
index 14638235f7b2..50467cefdbd8 100644
--- a/fs/dlm/recover.c
+++ b/fs/dlm/recover.c
@@ -715,6 +715,7 @@ void dlm_recover_rsbs(struct dlm_ls *ls)
 
 int dlm_create_root_list(struct dlm_ls *ls)
 {
+	struct rb_node *n;
 	struct dlm_rsb *r;
 	int i, error = 0;
 
@@ -727,7 +728,8 @@ int dlm_create_root_list(struct dlm_ls *ls)
 
 	for (i = 0; i < ls->ls_rsbtbl_size; i++) {
 		spin_lock(&ls->ls_rsbtbl[i].lock);
-		list_for_each_entry(r, &ls->ls_rsbtbl[i].list, res_hashchain) {
+		for (n = rb_first(&ls->ls_rsbtbl[i].keep); n; n = rb_next(n)) {
+			r = rb_entry(n, struct dlm_rsb, res_hashnode);
 			list_add(&r->res_root_list, &ls->ls_root_list);
 			dlm_hold_rsb(r);
 		}
@@ -741,7 +743,8 @@ int dlm_create_root_list(struct dlm_ls *ls)
 			continue;
 		}
 
-		list_for_each_entry(r, &ls->ls_rsbtbl[i].toss, res_hashchain) {
+		for (n = rb_first(&ls->ls_rsbtbl[i].toss); n; n = rb_next(n)) {
+			r = rb_entry(n, struct dlm_rsb, res_hashnode);
 			list_add(&r->res_root_list, &ls->ls_root_list);
 			dlm_hold_rsb(r);
 		}
@@ -771,16 +774,18 @@ void dlm_release_root_list(struct dlm_ls *ls)
 
 void dlm_clear_toss_list(struct dlm_ls *ls)
 {
-	struct dlm_rsb *r, *safe;
+	struct rb_node *n, *next;
+	struct dlm_rsb *rsb;
 	int i;
 
 	for (i = 0; i < ls->ls_rsbtbl_size; i++) {
 		spin_lock(&ls->ls_rsbtbl[i].lock);
-		list_for_each_entry_safe(r, safe, &ls->ls_rsbtbl[i].toss,
-					 res_hashchain) {
-			if (dlm_no_directory(ls) || !is_master(r)) {
-				list_del(&r->res_hashchain);
-				dlm_free_rsb(r);
+		for (n = rb_first(&ls->ls_rsbtbl[i].toss); n; n = next) {
+			next = rb_next(n);;
+			rsb = rb_entry(n, struct dlm_rsb, res_hashnode);
+			if (dlm_no_directory(ls) || !is_master(rsb)) {
+				rb_erase(n, &ls->ls_rsbtbl[i].toss);
+				dlm_free_rsb(rsb);
 			}
 		}
 		spin_unlock(&ls->ls_rsbtbl[i].lock);