Commit c217adfc authored by David Teigland's avatar David Teigland
Browse files

dlm: fix add_scan and del_scan usage 



Remove a few calls to add_scan() and del_scan() in cases where
the rsb is a dir record, so the rsb should never be placed on
the scan list at all.  Add WARN_ON to catch cases where this
is done.

Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
parent 4f5957a9

fs/dlm/lock.c

+35 −22
Original line number Diff line number Diff line
@@ -420,6 +420,9 @@ static void del_scan(struct dlm_ls *ls, struct dlm_rsb *r) 
{

	struct dlm_rsb *first;



	/* active rsbs should never be on the scan list */

	WARN_ON(!rsb_flag(r, RSB_INACTIVE));



	spin_lock_bh(&ls->ls_scan_lock);

	r->res_toss_time = 0;
@@ -457,17 +460,16 @@ static void add_scan(struct dlm_ls *ls, struct dlm_rsb *r) 
	int our_nodeid = dlm_our_nodeid();

	struct dlm_rsb *first;



	/* If we're the directory record for this rsb, and

	 * we're not the master of it, then we need to wait

	 * for the master node to send us a dir remove for

	 * before removing the dir record.

	 */

	if (!dlm_no_directory(ls) &&

	/* A dir record for a remote master rsb should never be on the scan list. */

	WARN_ON(!dlm_no_directory(ls) &&

		(r->res_master_nodeid != our_nodeid) &&

	    (dlm_dir_nodeid(r) == our_nodeid)) {

		del_scan(ls, r);

		return;

	}

		(dlm_dir_nodeid(r) == our_nodeid));



	/* An active rsb should never be on the scan list. */

	WARN_ON(!rsb_flag(r, RSB_INACTIVE));



	/* An rsb should not already be on the scan list. */

	WARN_ON(!list_empty(&r->res_scan_list));



	spin_lock_bh(&ls->ls_scan_lock);

	/* set the new rsb absolute expire time in the rsb */
@@ -479,12 +481,6 @@ static void add_scan(struct dlm_ls *ls, struct dlm_rsb *r) 
		list_add_tail(&r->res_scan_list, &ls->ls_scan_list);

		enable_scan_timer(ls, r->res_toss_time);

	} else {

		/* check if the rsb was already queued, if so delete

		 * it from the toss queue

		 */

		if (!list_empty(&r->res_scan_list))

			list_del(&r->res_scan_list);



		/* try to get the maybe new first element and then add

		 * to this rsb with the oldest expire time to the end

		 * of the queue. If the list was empty before this
@@ -807,10 +803,12 @@ static int find_rsb_dir(struct dlm_ls *ls, const void *name, int len, 
		r->res_first_lkid = 0;

	}



	/* A dir record will not be on the scan list. */

	if (r->res_dir_nodeid != our_nodeid)

		del_scan(ls, r);

	list_move(&r->res_slow_list, &ls->ls_slow_active);

	rsb_clear_flag(r, RSB_INACTIVE);

	kref_init(&r->res_ref);

	del_scan(ls, r);

	kref_init(&r->res_ref); /* ref is now used in active state */

	write_unlock_bh(&ls->ls_rsbtbl_lock);



	goto out;
@@ -1272,7 +1270,10 @@ int dlm_master_lookup(struct dlm_ls *ls, int from_nodeid, const char *name, 
	__dlm_master_lookup(ls, r, our_nodeid, from_nodeid, true, flags,

			    r_nodeid, result);



	add_scan(ls, r);

	/* A dir record rsb should never be on scan list. */

	/* Try to fix this with del_scan? */

	WARN_ON(!list_empty(&r->res_scan_list));



	write_unlock_bh(&ls->ls_rsbtbl_lock);



	return 0;
@@ -1305,7 +1306,6 @@ int dlm_master_lookup(struct dlm_ls *ls, int from_nodeid, const char *name, 
	}



	list_add(&r->res_slow_list, &ls->ls_slow_inactive);

	add_scan(ls, r);

	write_unlock_bh(&ls->ls_rsbtbl_lock);



	if (result)
@@ -1346,10 +1346,23 @@ static void deactivate_rsb(struct kref *kref) 
{

	struct dlm_rsb *r = container_of(kref, struct dlm_rsb, res_ref);

	struct dlm_ls *ls = r->res_ls;

	int our_nodeid = dlm_our_nodeid();



	DLM_ASSERT(list_empty(&r->res_root_list), dlm_print_rsb(r););

	rsb_set_flag(r, RSB_INACTIVE);

	list_move(&r->res_slow_list, &ls->ls_slow_inactive);



	/*

	 * When the rsb becomes unused:

	 * - If it's not a dir record for a remote master rsb,

	 *   then it is put on the scan list to be freed.

	 * - If it's a dir record for a remote master rsb,

	 *   then it is kept in the inactive state until

	 *   receive_remove() from the master node.

	 */

	if (!dlm_no_directory(ls) &&

	    (r->res_master_nodeid != our_nodeid) &&

	    (dlm_dir_nodeid(r) != our_nodeid))

		add_scan(ls, r);



	if (r->res_lvbptr) {