+ldlm_inodebits_compat_queue(struct list_head *queue, struct ldlm_lock *req,
+ struct list_head *work_list)
+{
+ struct list_head *tmp;
+ struct ldlm_lock *lock;
+ __u64 req_bits = req->l_policy_data.l_inodebits.bits;
+ __u64 *try_bits = &req->l_policy_data.l_inodebits.try_bits;
+ int compat = 1;
+
+ ENTRY;
+
+ /* There is no sense in lock with no bits set. Also such a lock
+ * would be compatible with any other bit lock.
+ * Meanwhile that can be true if there were just try_bits and all
+ * are failed, so just exit gracefully and let the caller to care.
+ */
+ if ((req_bits | *try_bits) == 0)
+ RETURN(0);
+
+ list_for_each(tmp, queue) {
+ struct list_head *mode_tail;
+
+ lock = list_entry(tmp, struct ldlm_lock, l_res_link);
+
+ /* We stop walking the queue if we hit ourselves so we don't
+ * take conflicting locks enqueued after us into account,
+ * or we'd wait forever. */
+ if (req == lock)
+ RETURN(compat);
+
+ /* last lock in mode group */
+ LASSERT(lock->l_sl_mode.prev != NULL);
+ mode_tail = &list_entry(lock->l_sl_mode.prev, struct ldlm_lock,
+ l_sl_mode)->l_res_link;
+
+ /* if request lock is not COS_INCOMPAT and COS is disabled,
+ * they are compatible, IOW this request is from a local
+ * transaction on a DNE system. */
+ if (lock->l_req_mode == LCK_COS && !ldlm_is_cos_incompat(req) &&
+ !ldlm_is_cos_enabled(req)) {
+ /* jump to last lock in mode group */
+ tmp = mode_tail;
+ continue;
+ }
+
+ /* locks' mode are compatible, bits don't matter */
+ if (lockmode_compat(lock->l_req_mode, req->l_req_mode)) {
+ /* jump to last lock in mode group */
+ tmp = mode_tail;
+ continue;
+ }
+
+ for (;;) {
+ struct list_head *head;
+
+ /* Advance loop cursor to last lock in policy group. */
+ tmp = &list_entry(lock->l_sl_policy.prev,
+ struct ldlm_lock,
+ l_sl_policy)->l_res_link;
+
+ /* New lock's try_bits are filtered out by ibits
+ * of all locks in both granted and waiting queues.
+ */
+ *try_bits &= ~(lock->l_policy_data.l_inodebits.bits |
+ lock->l_policy_data.l_inodebits.try_bits);
+
+ if ((req_bits | *try_bits) == 0)
+ RETURN(0);
+
+ /* The new lock ibits is more preferable than try_bits
+ * of waiting locks so drop conflicting try_bits in
+ * the waiting queue.
+ * Notice that try_bits of granted locks must be zero.
+ */
+ lock->l_policy_data.l_inodebits.try_bits &= ~req_bits;
+
+ /* Locks with overlapping bits conflict. */
+ if (lock->l_policy_data.l_inodebits.bits & req_bits) {
+ /* COS lock mode has a special compatibility
+ * requirement: it is only compatible with
+ * locks from the same client. */
+ if (lock->l_req_mode == LCK_COS &&
+ !ldlm_is_cos_incompat(req) &&
+ ldlm_is_cos_enabled(req) &&
+ lock->l_client_cookie == req->l_client_cookie)
+ goto not_conflicting;
+
+ /* Found a conflicting policy group. */
+ if (!work_list)
+ RETURN(0);
+
+ compat = 0;
+
+ /* Add locks of the policy group to @work_list
+ * as blocking locks for @req */
+ if (lock->l_blocking_ast)
+ ldlm_add_ast_work_item(lock, req,
+ work_list);
+ head = &lock->l_sl_policy;
+ list_for_each_entry(lock, head, l_sl_policy)
+ if (lock->l_blocking_ast)
+ ldlm_add_ast_work_item(lock,
+ req, work_list);
+ }
+not_conflicting:
+ if (tmp == mode_tail)
+ break;
+
+ tmp = tmp->next;
+ lock = list_entry(tmp, struct ldlm_lock, l_res_link);
+ } /* Loop over policy groups within one mode group. */
+ } /* Loop over mode groups within @queue. */
+
+ RETURN(compat);
+}
+
+/**
+ * Process a granting attempt for IBITS lock.
+ * Must be called with ns lock held
+ *
+ * This function looks for any conflicts for \a lock in the granted or
+ * waiting queues. The lock is granted if no conflicts are found in
+ * either queue.
+ */
+int ldlm_process_inodebits_lock(struct ldlm_lock *lock, __u64 *flags,
+ enum ldlm_process_intention intention,
+ enum ldlm_error *err,
+ struct list_head *work_list)
+{
+ struct ldlm_resource *res = lock->l_resource;
+ struct list_head *grant_work = intention == LDLM_PROCESS_ENQUEUE ?
+ NULL : work_list;
+ int rc;
+
+ ENTRY;
+
+ LASSERT(!ldlm_is_granted(lock));
+ check_res_locked(res);
+
+ if (intention == LDLM_PROCESS_RESCAN) {
+ struct list_head *bl_list;
+
+ if (*flags & LDLM_FL_BLOCK_NOWAIT) {
+ bl_list = NULL;
+ *err = ELDLM_LOCK_WOULDBLOCK;
+ } else {
+ bl_list = work_list;
+ *err = ELDLM_LOCK_ABORTED;
+ }
+
+ LASSERT(lock->l_policy_data.l_inodebits.bits != 0);
+
+ /* It is possible that some of granted locks was not canceled
+ * but converted and is kept in granted queue. So there is
+ * a window where lock with 'ast_sent' might become granted
+ * again. Meanwhile a new lock may appear in that window and
+ * conflicts with the converted lock so the following scenario
+ * is possible:
+ *
+ * 1) lock1 conflicts with lock2
+ * 2) bl_ast was sent for lock2
+ * 3) lock3 comes and conflicts with lock2 too
+ * 4) no bl_ast sent because lock2->l_bl_ast_sent is 1
+ * 5) lock2 was converted for lock1 but not for lock3
+ * 6) lock1 granted, lock3 still is waiting for lock2, but
+ * there will never be another bl_ast for that
+ *
+ * To avoid this scenario the work_list is used below to collect
+ * any blocked locks from granted queue during every reprocess
+ * and bl_ast will be sent if needed.
+ */
+ rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock,
+ bl_list);
+ if (!rc)
+ RETURN(LDLM_ITER_STOP);
+ rc = ldlm_inodebits_compat_queue(&res->lr_waiting, lock, NULL);
+ if (!rc)
+ RETURN(LDLM_ITER_STOP);
+
+ /* grant also try_bits if any */
+ if (lock->l_policy_data.l_inodebits.try_bits != 0) {
+ lock->l_policy_data.l_inodebits.bits |=
+ lock->l_policy_data.l_inodebits.try_bits;
+ lock->l_policy_data.l_inodebits.try_bits = 0;
+ *flags |= LDLM_FL_LOCK_CHANGED;
+ }
+ ldlm_resource_unlink_lock(lock);
+ ldlm_grant_lock(lock, grant_work);
+
+ *err = ELDLM_OK;
+ RETURN(LDLM_ITER_CONTINUE);
+ }
+
+ rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, work_list);
+ rc += ldlm_inodebits_compat_queue(&res->lr_waiting, lock, work_list);
+
+ if (rc != 2) {
+ /* if there were only bits to try and all are conflicting */
+ if ((lock->l_policy_data.l_inodebits.bits |
+ lock->l_policy_data.l_inodebits.try_bits) == 0) {
+ *err = ELDLM_LOCK_WOULDBLOCK;
+ } else {
+ *err = ELDLM_OK;
+ }
+ } else {
+ /* grant also all remaining try_bits */
+ if (lock->l_policy_data.l_inodebits.try_bits != 0) {
+ lock->l_policy_data.l_inodebits.bits |=
+ lock->l_policy_data.l_inodebits.try_bits;
+ lock->l_policy_data.l_inodebits.try_bits = 0;
+ *flags |= LDLM_FL_LOCK_CHANGED;
+ }
+ LASSERT(lock->l_policy_data.l_inodebits.bits);
+ ldlm_resource_unlink_lock(lock);
+ ldlm_grant_lock(lock, grant_work);
+ *err = ELDLM_OK;
+ }
+
+ RETURN(LDLM_ITER_CONTINUE);
+}
+#endif /* HAVE_SERVER_SUPPORT */
+
+void ldlm_ibits_policy_wire_to_local(const union ldlm_wire_policy_data *wpolicy,
+ union ldlm_policy_data *lpolicy)
+{
+ lpolicy->l_inodebits.bits = wpolicy->l_inodebits.bits;
+ lpolicy->l_inodebits.try_bits = wpolicy->l_inodebits.try_bits;
+}
+
+void ldlm_ibits_policy_local_to_wire(const union ldlm_policy_data *lpolicy,
+ union ldlm_wire_policy_data *wpolicy)
+{
+ memset(wpolicy, 0, sizeof(*wpolicy));
+ wpolicy->l_inodebits.bits = lpolicy->l_inodebits.bits;
+ wpolicy->l_inodebits.try_bits = lpolicy->l_inodebits.try_bits;
+}
+
+/**
+ * Attempt to convert already granted IBITS lock with several bits set to
+ * a lock with less bits (downgrade).
+ *
+ * Such lock conversion is used to keep lock with non-blocking bits instead of
+ * cancelling it, introduced for better support of DoM files.
+ */
+int ldlm_inodebits_drop(struct ldlm_lock *lock, __u64 to_drop)