[PATCHv2 dlm/next 9/9] dlm: convert lkbidr to rwlock

Alexander Aring
2024-04-15T18:39:48Z

This patch converts lkbidr lock to rwlock. The most time we doing
lookups of idr only this can be done by holding the read lock only.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
---
fs/dlm/dlm_internal.h | 2 +-
fs/dlm/lock.c | 44 +++++++------------------------------------
fs/dlm/lockspace.c | 6 +++---
3 files changed, 11 insertions(+), 41 deletions(-)

diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index b675bffb61ae..19e57cbd5b13 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -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;
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index 790d0fd76bbe..bbbc9593a64e 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -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);

diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index 04f4c74831ce..5ce26882159e 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -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;
}

--
2.43.0