Commit 15fd7e55 authored by Alexander Aring's avatar Alexander Aring Committed by David Teigland
Browse files

dlm: use rwlock for lkbidr 



Convert the lock for lkbidr to an rwlock.  Most idr lookups will use
the read lock.

Signed-off-by: default avatarAlexander Aring <aahringo@redhat.com>
Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
parent e9131359

fs/dlm/dlm_internal.h

+1 −1
Original line number Diff line number Diff line
@@ -582,7 +582,7 @@ struct dlm_ls { 
	struct kobject		ls_kobj;



	struct idr		ls_lkbidr;

	spinlock_t		ls_lkbidr_spin;

	rwlock_t		ls_lkbidr_lock;



	struct rhashtable	ls_rsbtbl;

	rwlock_t		ls_rsbtbl_lock;

fs/dlm/lock.c

+7 −37
Original line number Diff line number Diff line
@@ -1522,11 +1522,11 @@ static int _create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret, 
	INIT_LIST_HEAD(&lkb->lkb_ownqueue);

	INIT_LIST_HEAD(&lkb->lkb_rsb_lookup);



	spin_lock_bh(&ls->ls_lkbidr_spin);

	write_lock_bh(&ls->ls_lkbidr_lock);

	rv = idr_alloc(&ls->ls_lkbidr, lkb, start, end, GFP_NOWAIT);

	if (rv >= 0)

		lkb->lkb_id = rv;

	spin_unlock_bh(&ls->ls_lkbidr_spin);

	write_unlock_bh(&ls->ls_lkbidr_lock);



	if (rv < 0) {

		log_error(ls, "create_lkb idr error %d", rv);
@@ -1547,11 +1547,11 @@ static int find_lkb(struct dlm_ls *ls, uint32_t lkid, struct dlm_lkb **lkb_ret) 
{

	struct dlm_lkb *lkb;



	spin_lock_bh(&ls->ls_lkbidr_spin);

	read_lock_bh(&ls->ls_lkbidr_lock);

	lkb = idr_find(&ls->ls_lkbidr, lkid);

	if (lkb)

		kref_get(&lkb->lkb_ref);

	spin_unlock_bh(&ls->ls_lkbidr_spin);

	read_unlock_bh(&ls->ls_lkbidr_lock);



	*lkb_ret = lkb;

	return lkb ? 0 : -ENOENT;
@@ -1567,36 +1567,6 @@ static void kill_lkb(struct kref *kref) 
	DLM_ASSERT(!lkb->lkb_status, dlm_print_lkb(lkb););

}



/* TODO move this to lib/refcount.c */

static __must_check bool

dlm_refcount_dec_and_lock_bh(refcount_t *r, spinlock_t *lock)

__cond_acquires(lock)

{

	if (refcount_dec_not_one(r))

		return false;



	spin_lock_bh(lock);

	if (!refcount_dec_and_test(r)) {

		spin_unlock_bh(lock);

		return false;

	}



	return true;

}



/* TODO move this to include/linux/kref.h */

static inline int dlm_kref_put_lock_bh(struct kref *kref,

				       void (*release)(struct kref *kref),

				       spinlock_t *lock)

{

	if (dlm_refcount_dec_and_lock_bh(&kref->refcount, lock)) {

		release(kref);

		return 1;

	}



	return 0;

}



/* __put_lkb() is used when an lkb may not have an rsb attached to

   it so we need to provide the lockspace explicitly */
@@ -1605,11 +1575,11 @@ static int __put_lkb(struct dlm_ls *ls, struct dlm_lkb *lkb) 
	uint32_t lkid = lkb->lkb_id;

	int rv;



	rv = dlm_kref_put_lock_bh(&lkb->lkb_ref, kill_lkb,

				  &ls->ls_lkbidr_spin);

	rv = dlm_kref_put_write_lock_bh(&lkb->lkb_ref, kill_lkb,

					&ls->ls_lkbidr_lock);

	if (rv) {

		idr_remove(&ls->ls_lkbidr, lkid);

		spin_unlock_bh(&ls->ls_lkbidr_spin);

		write_unlock_bh(&ls->ls_lkbidr_lock);



		detach_lkb(lkb);

fs/dlm/lockspace.c

+3 −3
Original line number Diff line number Diff line
@@ -431,7 +431,7 @@ static int new_lockspace(const char *name, const char *cluster, 
		goto out_lsfree;



	idr_init(&ls->ls_lkbidr);

	spin_lock_init(&ls->ls_lkbidr_spin);

	rwlock_init(&ls->ls_lkbidr_lock);



	INIT_LIST_HEAD(&ls->ls_waiters);

	spin_lock_init(&ls->ls_waiters_lock);
@@ -676,7 +676,7 @@ static int lockspace_busy(struct dlm_ls *ls, int force) 
{

	int rv;



	spin_lock_bh(&ls->ls_lkbidr_spin);

	read_lock_bh(&ls->ls_lkbidr_lock);

	if (force == 0) {

		rv = idr_for_each(&ls->ls_lkbidr, lkb_idr_is_any, ls);

	} else if (force == 1) {
@@ -684,7 +684,7 @@ static int lockspace_busy(struct dlm_ls *ls, int force) 
	} else {

		rv = 0;

	}

	spin_unlock_bh(&ls->ls_lkbidr_spin);

	read_unlock_bh(&ls->ls_lkbidr_lock);

	return rv;

}