dlm: use a new list for recovery of master rsb names

Add a new "masters_list" for master rsb structs, with a new
rwlock. The new list is created and used during the recovery
process to send the master rsb names to new nodes. With this
change, the current "root_list" can be used without locking.

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

1 files changed, 64 insertions, 0 deletions

diff --git a/fs/dlm/recoverd.c b/fs/dlm/recoverd.c
index 8eb42554ccb0..dfce8fc6a783 100644
--- a/fs/dlm/recoverd.c
+++ b/fs/dlm/recoverd.c
@@ -20,6 +20,48 @@
 #include "requestqueue.h"
 #include "recoverd.h"
 
+static int dlm_create_masters_list(struct dlm_ls *ls)
+{
+	struct rb_node *n;
+	struct dlm_rsb *r;
+	int i, error = 0;
+
+	write_lock(&ls->ls_masters_lock);
+	if (!list_empty(&ls->ls_masters_list)) {
+		log_error(ls, "root list not empty");
+		error = -EINVAL;
+		goto out;
+	}
+
+	for (i = 0; i < ls->ls_rsbtbl_size; i++) {
+		spin_lock_bh(&ls->ls_rsbtbl[i].lock);
+		for (n = rb_first(&ls->ls_rsbtbl[i].keep); n; n = rb_next(n)) {
+			r = rb_entry(n, struct dlm_rsb, res_hashnode);
+			if (r->res_nodeid)
+				continue;
+
+			list_add(&r->res_masters_list, &ls->ls_masters_list);
+			dlm_hold_rsb(r);
+		}
+		spin_unlock_bh(&ls->ls_rsbtbl[i].lock);
+	}
+ out:
+	write_unlock(&ls->ls_masters_lock);
+	return error;
+}
+
+static void dlm_release_masters_list(struct dlm_ls *ls)
+{
+	struct dlm_rsb *r, *safe;
+
+	write_lock(&ls->ls_masters_lock);
+	list_for_each_entry_safe(r, safe, &ls->ls_masters_list, res_masters_list) {
+		list_del_init(&r->res_masters_list);
+		dlm_put_rsb(r);
+	}
+	write_unlock(&ls->ls_masters_lock);
+}
+
 static void dlm_create_root_list(struct dlm_ls *ls)
 {
 	struct rb_node *n;
@@ -123,6 +165,23 @@ static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
 
 	dlm_recover_dir_nodeid(ls);
 
+	/* Create a snapshot of all active rsbs were we are the master of.
+	 * During the barrier between dlm_recover_members_wait() and
+	 * dlm_recover_directory() other nodes can dump their necessary
+	 * directory dlm_rsb (r->res_dir_nodeid == nodeid) in rcom
+	 * communication dlm_copy_master_names() handling.
+	 *
+	 * TODO We should create a per lockspace list that contains rsbs
+	 * that we are the master of. Instead of creating this list while
+	 * recovery we keep track of those rsbs while locking handling and
+	 * recovery can use it when necessary.
+	 */
+	error = dlm_create_masters_list(ls);
+	if (error) {
+		log_rinfo(ls, "dlm_create_masters_list error %d", error);
+		goto fail;
+	}
+
 	ls->ls_recover_dir_sent_res = 0;
 	ls->ls_recover_dir_sent_msg = 0;
 	ls->ls_recover_locks_in = 0;
@@ -132,6 +191,7 @@ static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
 	error = dlm_recover_members_wait(ls, rv->seq);
 	if (error) {
 		log_rinfo(ls, "dlm_recover_members_wait error %d", error);
+		dlm_release_masters_list(ls);
 		goto fail;
 	}
 
@@ -145,6 +205,7 @@ static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
 	error = dlm_recover_directory(ls, rv->seq);
 	if (error) {
 		log_rinfo(ls, "dlm_recover_directory error %d", error);
+		dlm_release_masters_list(ls);
 		goto fail;
 	}
 
@@ -153,9 +214,12 @@ static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
 	error = dlm_recover_directory_wait(ls, rv->seq);
 	if (error) {
 		log_rinfo(ls, "dlm_recover_directory_wait error %d", error);
+		dlm_release_masters_list(ls);
 		goto fail;
 	}
 
+	dlm_release_masters_list(ls);
+
 	log_rinfo(ls, "dlm_recover_directory %u out %u messages",
 		  ls->ls_recover_dir_sent_res, ls->ls_recover_dir_sent_msg);