diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h index 0562099e60eb..d534a4bc162b 100644 --- a/fs/dlm/dlm_internal.h +++ b/fs/dlm/dlm_internal.h @@ -295,6 +295,7 @@ struct dlm_lkb { void *lkb_astparam; /* caller's ast arg */ struct dlm_user_args *lkb_ua; }; + struct rcu_head rcu; }; /* diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index 9d3ec359d5e3..865dc70a9dfc 100644 --- a/fs/dlm/lock.c +++ b/fs/dlm/lock.c @@ -1527,11 +1527,21 @@ static int find_lkb(struct dlm_ls *ls, uint32_t lkid, struct dlm_lkb **lkb_ret) { struct dlm_lkb *lkb; - read_lock_bh(&ls->ls_lkbxa_lock); + rcu_read_lock(); lkb = xa_load(&ls->ls_lkbxa, lkid); - if (lkb) - kref_get(&lkb->lkb_ref); - read_unlock_bh(&ls->ls_lkbxa_lock); + if (lkb) { + /* check if lkb is still part of lkbxa under lkbxa_lock as + * the lkb_ref is tight to the lkbxa data structure, see + * __put_lkb(). + */ + read_lock_bh(&ls->ls_lkbxa_lock); + if (kref_read(&lkb->lkb_ref)) + kref_get(&lkb->lkb_ref); + else + lkb = NULL; + read_unlock_bh(&ls->ls_lkbxa_lock); + } + rcu_read_unlock(); *lkb_ret = lkb; return lkb ? 0 : -ENOENT; diff --git a/fs/dlm/memory.c b/fs/dlm/memory.c index 442898cf7185..5c35cc67aca4 100644 --- a/fs/dlm/memory.c +++ b/fs/dlm/memory.c @@ -115,8 +115,10 @@ struct dlm_lkb *dlm_allocate_lkb(void) return kmem_cache_zalloc(lkb_cache, GFP_ATOMIC); } -void dlm_free_lkb(struct dlm_lkb *lkb) +static void __free_lkb_rcu(struct rcu_head *rcu) { + struct dlm_lkb *lkb = container_of(rcu, struct dlm_lkb, rcu); + if (test_bit(DLM_DFL_USER_BIT, &lkb->lkb_dflags)) { struct dlm_user_args *ua; ua = lkb->lkb_ua; @@ -129,6 +131,11 @@ void dlm_free_lkb(struct dlm_lkb *lkb) kmem_cache_free(lkb_cache, lkb); } +void dlm_free_lkb(struct dlm_lkb *lkb) +{ + call_rcu(&lkb->rcu, __free_lkb_rcu); +} + struct dlm_mhandle *dlm_allocate_mhandle(void) { return kmem_cache_alloc(mhandle_cache, GFP_ATOMIC);