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Commit 2f5bf1f2 authored by Sunil Mushran's avatar Sunil Mushran Committed by Mark Fasheh
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ocfs2_dlm: Check for migrateable lockres in dlm_empty_lockres() 



In dlm_migrate_lockres(), we check upfront whether the lockres is a
candidate for migration. This patch encapsulates that code in a separate
function so that dlm_empty_lockres() can also use it during umount. This
patch addresses the umount process spinning problem.

Signed-off-by: default avatarSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: default avatarMark Fasheh <mark.fasheh@oracle.com>
parent 78062cb2

fs/ocfs2/dlm/dlmdomain.c

+2 −0
Original line number Diff line number Diff line
@@ -657,6 +657,8 @@ void dlm_unregister_domain(struct dlm_ctxt *dlm) 
		dlm_kick_thread(dlm, NULL);



		while (dlm_migrate_all_locks(dlm)) {

			/* Give dlm_thread time to purge the lockres' */

			msleep(500);

			mlog(0, "%s: more migration to do\n", dlm->name);

		}

		dlm_mark_domain_leaving(dlm);

fs/ocfs2/dlm/dlmmaster.c

+65 −34
Original line number Diff line number Diff line
@@ -2424,6 +2424,57 @@ static void dlm_deref_lockres_worker(struct dlm_work_item *item, void *data) 
	dlm_lockres_put(res);

}



/* Checks whether the lockres can be migrated. Returns 0 if yes, < 0

 * if not. If 0, numlocks is set to the number of locks in the lockres.

 */

static int dlm_is_lockres_migrateable(struct dlm_ctxt *dlm,

				      struct dlm_lock_resource *res,

				      int *numlocks)

{

	int ret;

	int i;

	int count = 0;

	struct list_head *queue, *iter;

	struct dlm_lock *lock;



	assert_spin_locked(&res->spinlock);



	ret = -EINVAL;

	if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {

		mlog(0, "cannot migrate lockres with unknown owner!\n");

		goto leave;

	}



	if (res->owner != dlm->node_num) {

		mlog(0, "cannot migrate lockres this node doesn't own!\n");

		goto leave;

	}



	ret = 0;

	queue = &res->granted;

	for (i = 0; i < 3; i++) {

		list_for_each(iter, queue) {

			lock = list_entry(iter, struct dlm_lock, list);

			++count;

			if (lock->ml.node == dlm->node_num) {

				mlog(0, "found a lock owned by this node still "

				     "on the %s queue!  will not migrate this "

				     "lockres\n", (i == 0 ? "granted" :

						   (i == 1 ? "converting" :

						    "blocked")));

				ret = -ENOTEMPTY;

				goto leave;

			}

		}

		queue++;

	}



	*numlocks = count;

	mlog(0, "migrateable lockres having %d locks\n", *numlocks);



leave:

	return ret;

}



/*

 * DLM_MIGRATE_LOCKRES
@@ -2437,14 +2488,12 @@ static int dlm_migrate_lockres(struct dlm_ctxt *dlm, 
	struct dlm_master_list_entry *mle = NULL;

	struct dlm_master_list_entry *oldmle = NULL;

 	struct dlm_migratable_lockres *mres = NULL;

	int ret = -EINVAL;

	int ret = 0;

	const char *name;

	unsigned int namelen;

	int mle_added = 0;

	struct list_head *queue, *iter;

	int i;

	struct dlm_lock *lock;

	int empty = 1, wake = 0;

	int numlocks;

	int wake = 0;



	if (!dlm_grab(dlm))

		return -EINVAL;
@@ -2458,42 +2507,16 @@ static int dlm_migrate_lockres(struct dlm_ctxt *dlm, 
	 * ensure this lockres is a proper candidate for migration

	 */

	spin_lock(&res->spinlock);

	if (res->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {

		mlog(0, "cannot migrate lockres with unknown owner!\n");

		spin_unlock(&res->spinlock);

		goto leave;

	}

	if (res->owner != dlm->node_num) {

		mlog(0, "cannot migrate lockres this node doesn't own!\n");

		spin_unlock(&res->spinlock);

		goto leave;

	}

	mlog(0, "checking queues...\n");

	queue = &res->granted;

	for (i=0; i<3; i++) {

		list_for_each(iter, queue) {

			lock = list_entry (iter, struct dlm_lock, list);

			empty = 0;

			if (lock->ml.node == dlm->node_num) {

				mlog(0, "found a lock owned by this node "

				     "still on the %s queue!  will not "

				     "migrate this lockres\n",

				     i==0 ? "granted" :

				     (i==1 ? "converting" : "blocked"));

	ret = dlm_is_lockres_migrateable(dlm, res, &numlocks);

	if (ret < 0) {

		spin_unlock(&res->spinlock);

				ret = -ENOTEMPTY;

		goto leave;

	}

		}

		queue++;

	}

	mlog(0, "all locks on this lockres are nonlocal.  continuing\n");

	spin_unlock(&res->spinlock);



	/* no work to do */

	if (empty) {

	if (numlocks == 0) {

		mlog(0, "no locks were found on this lockres! done!\n");

		ret = 0;

		goto leave;

	}
@@ -2729,6 +2752,7 @@ int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) 
{

	int ret;

	int lock_dropped = 0;

	int numlocks;



	spin_lock(&res->spinlock);

	if (res->owner != dlm->node_num) {
@@ -2740,6 +2764,13 @@ int dlm_empty_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) 
		spin_unlock(&res->spinlock);

		goto leave;

	}



	/* No need to migrate a lockres having no locks */

	ret = dlm_is_lockres_migrateable(dlm, res, &numlocks);

	if (ret >= 0 && numlocks == 0) {

		spin_unlock(&res->spinlock);

		goto leave;

	}

	spin_unlock(&res->spinlock);



	/* Wheee! Migrate lockres here! Will sleep so drop spinlock. */