#include <linux/lustre_dlm.h>
#include <linux/lustre_lib.h>
-/* invariants:
- - only the owner of the lock changes l_owner/l_depth
- - if a non-owner changes or checks the variables a spin lock is taken
-*/
-
-void l_lock_init(struct lustre_lock *lock)
+/*
+ * ldlm locking uses resource to serialize access to locks
+ * but there is a case when we change resource of lock upon
+ * enqueue reply. we rely on that lock->l_resource = new_res
+ * is atomic
+ */
+struct ldlm_resource * lock_res_and_lock(struct ldlm_lock *lock)
{
- sema_init(&lock->l_sem, 1);
- spin_lock_init(&lock->l_spin);
+ struct ldlm_resource *res = lock->l_resource;
+
+ if (!res->lr_namespace->ns_client) {
+ /* on server-side resource of lock doesn't change */
+ lock_res(res);
+ return res;
+ }
+
+ lock_bitlock(lock);
+ res = lock->l_resource;
+ lock_res(res);
+ return res;
}
-void l_lock(struct lustre_lock *lock)
+void unlock_res_and_lock(struct ldlm_lock *lock)
{
- int owner = 0;
-
- spin_lock(&lock->l_spin);
- if (lock->l_owner == current)
- owner = 1;
- spin_unlock(&lock->l_spin);
-
- /* This is safe to increment outside the spinlock because we
- * can only have 1 CPU running on the current task
- * (i.e. l_owner == current), regardless of the number of CPUs.
- */
- if (owner) {
- ++lock->l_depth;
- } else {
- down(&lock->l_sem);
- spin_lock(&lock->l_spin);
- lock->l_owner = current;
- lock->l_depth = 0;
- spin_unlock(&lock->l_spin);
- }
-}
+ struct ldlm_resource *res = lock->l_resource;
-void l_unlock(struct lustre_lock *lock)
-{
- LASSERTF(lock->l_owner == current, "lock %p, current %p\n",
- lock->l_owner, current);
- LASSERTF(lock->l_depth >= 0, "depth %d\n", lock->l_depth);
- spin_lock(&lock->l_spin);
- if (--lock->l_depth < 0) {
- lock->l_owner = NULL;
- spin_unlock(&lock->l_spin);
- up(&lock->l_sem);
+ if (!res->lr_namespace->ns_client) {
+ /* on server-side resource of lock doesn't change */
+ unlock_res(res);
return;
}
- spin_unlock(&lock->l_spin);
-}
-int l_has_lock(struct lustre_lock *lock)
-{
- int depth = -1, owner = 0;
-
- spin_lock(&lock->l_spin);
- if (lock->l_owner == current) {
- depth = lock->l_depth;
- owner = 1;
- }
- spin_unlock(&lock->l_spin);
-
- if (depth >= 0)
- CDEBUG(D_INFO, "lock_depth: %d\n", depth);
- return owner;
-}
-
-#ifdef __KERNEL__
-#include <linux/lustre_version.h>
-void l_check_no_ns_lock(struct ldlm_namespace *ns)
-{
- static unsigned long next_msg;
-
- if (l_has_lock(&ns->ns_lock) && time_after(jiffies, next_msg)) {
- CERROR("namespace %s lock held illegally; tell phil\n",
- ns->ns_name);
- next_msg = jiffies + 60 * HZ;
- }
+ unlock_res(res);
+ unlock_bitlock(lock);
}
-#else
-void l_check_no_ns_lock(struct ldlm_namespace *ns)
-{
- if (l_has_lock(&ns->ns_lock)) {
- CERROR("namespace %s lock held illegally; tell phil\n",
- ns->ns_name);
- }
-}
-#endif /* __KERNEL__ */