/** * Process a granting attempt for plain 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. * * If \a first_enq is 0 (ie, called from ldlm_reprocess_queue): * - blocking ASTs have already been sent * * If \a first_enq is 1 (ie, called from ldlm_lock_enqueue): * - blocking ASTs have not been sent yet, so list of conflicting locks * would be collected and ASTs sent. */ int ldlm_process_plain_lock(struct ldlm_lock *lock, __u64 *flags, int first_enq, ldlm_error_t *err, struct list_head *work_list) { struct ldlm_resource *res = lock->l_resource; struct list_head rpc_list; int rc; ENTRY; LASSERT(lock->l_granted_mode != lock->l_req_mode); check_res_locked(res); LASSERT(list_empty(&res->lr_converting)); INIT_LIST_HEAD(&rpc_list); if (!first_enq) { LASSERT(work_list != NULL); rc = ldlm_plain_compat_queue(&res->lr_granted, lock, NULL); if (!rc) RETURN(LDLM_ITER_STOP); rc = ldlm_plain_compat_queue(&res->lr_waiting, lock, NULL); if (!rc) RETURN(LDLM_ITER_STOP); ldlm_resource_unlink_lock(lock); ldlm_grant_lock(lock, work_list); RETURN(LDLM_ITER_CONTINUE); } restart: rc = ldlm_plain_compat_queue(&res->lr_granted, lock, &rpc_list); rc += ldlm_plain_compat_queue(&res->lr_waiting, lock, &rpc_list); if (rc != 2) { /* If either of the compat_queue()s returned 0, then we * have ASTs to send and must go onto the waiting list. * * bug 2322: we used to unlink and re-add here, which was a * terrible folly -- if we goto restart, we could get * re-ordered! Causes deadlock, because ASTs aren't sent! */ if (list_empty(&lock->l_res_link)) ldlm_resource_add_lock(res, &res->lr_waiting, lock); unlock_res(res); rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &rpc_list, LDLM_WORK_BL_AST); lock_res(res); if (rc == -ERESTART) GOTO(restart, rc); *flags |= LDLM_FL_BLOCK_GRANTED; } else { ldlm_resource_unlink_lock(lock); ldlm_grant_lock(lock, NULL); } RETURN(0); }
/** * Callback handler for receiving incoming completion ASTs. * * This only can happen on client side. */ static void ldlm_handle_cp_callback(struct ptlrpc_request *req, struct ldlm_namespace *ns, struct ldlm_request *dlm_req, struct ldlm_lock *lock) { int lvb_len; LIST_HEAD(ast_list); int rc = 0; LDLM_DEBUG(lock, "client completion callback handler START"); if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_CANCEL_BL_CB_RACE)) { int to = cfs_time_seconds(1); while (to > 0) { schedule_timeout_and_set_state( TASK_INTERRUPTIBLE, to); if (lock->l_granted_mode == lock->l_req_mode || lock->l_flags & LDLM_FL_DESTROYED) break; } } lvb_len = req_capsule_get_size(&req->rq_pill, &RMF_DLM_LVB, RCL_CLIENT); if (lvb_len < 0) { LDLM_ERROR(lock, "Fail to get lvb_len, rc = %d", lvb_len); GOTO(out, rc = lvb_len); } else if (lvb_len > 0) { if (lock->l_lvb_len > 0) { /* for extent lock, lvb contains ost_lvb{}. */ LASSERT(lock->l_lvb_data != NULL); if (unlikely(lock->l_lvb_len < lvb_len)) { LDLM_ERROR(lock, "Replied LVB is larger than " "expectation, expected = %d, " "replied = %d", lock->l_lvb_len, lvb_len); GOTO(out, rc = -EINVAL); } } else if (ldlm_has_layout(lock)) { /* for layout lock, lvb has * variable length */ void *lvb_data; OBD_ALLOC(lvb_data, lvb_len); if (lvb_data == NULL) { LDLM_ERROR(lock, "No memory: %d.\n", lvb_len); GOTO(out, rc = -ENOMEM); } lock_res_and_lock(lock); LASSERT(lock->l_lvb_data == NULL); lock->l_lvb_data = lvb_data; lock->l_lvb_len = lvb_len; unlock_res_and_lock(lock); } } lock_res_and_lock(lock); if ((lock->l_flags & LDLM_FL_DESTROYED) || lock->l_granted_mode == lock->l_req_mode) { /* bug 11300: the lock has already been granted */ unlock_res_and_lock(lock); LDLM_DEBUG(lock, "Double grant race happened"); GOTO(out, rc = 0); } /* If we receive the completion AST before the actual enqueue returned, * then we might need to switch lock modes, resources, or extents. */ if (dlm_req->lock_desc.l_granted_mode != lock->l_req_mode) { lock->l_req_mode = dlm_req->lock_desc.l_granted_mode; LDLM_DEBUG(lock, "completion AST, new lock mode"); } if (lock->l_resource->lr_type != LDLM_PLAIN) { ldlm_convert_policy_to_local(req->rq_export, dlm_req->lock_desc.l_resource.lr_type, &dlm_req->lock_desc.l_policy_data, &lock->l_policy_data); LDLM_DEBUG(lock, "completion AST, new policy data"); } ldlm_resource_unlink_lock(lock); if (memcmp(&dlm_req->lock_desc.l_resource.lr_name, &lock->l_resource->lr_name, sizeof(lock->l_resource->lr_name)) != 0) { unlock_res_and_lock(lock); rc = ldlm_lock_change_resource(ns, lock, &dlm_req->lock_desc.l_resource.lr_name); if (rc < 0) { LDLM_ERROR(lock, "Failed to allocate resource"); GOTO(out, rc); } LDLM_DEBUG(lock, "completion AST, new resource"); CERROR("change resource!\n"); lock_res_and_lock(lock); } if (dlm_req->lock_flags & LDLM_FL_AST_SENT) { /* BL_AST locks are not needed in LRU. * Let ldlm_cancel_lru() be fast. */ ldlm_lock_remove_from_lru(lock); lock->l_flags |= LDLM_FL_CBPENDING | LDLM_FL_BL_AST; LDLM_DEBUG(lock, "completion AST includes blocking AST"); } if (lock->l_lvb_len > 0) { rc = ldlm_fill_lvb(lock, &req->rq_pill, RCL_CLIENT, lock->l_lvb_data, lvb_len); if (rc < 0) { unlock_res_and_lock(lock); GOTO(out, rc); } } ldlm_grant_lock(lock, &ast_list); unlock_res_and_lock(lock); LDLM_DEBUG(lock, "callback handler finished, about to run_ast_work"); /* Let Enqueue to call osc_lock_upcall() and initialize * l_ast_data */ OBD_FAIL_TIMEOUT(OBD_FAIL_OSC_CP_ENQ_RACE, 2); ldlm_run_ast_work(ns, &ast_list, LDLM_WORK_CP_AST); LDLM_DEBUG_NOLOCK("client completion callback handler END (lock %p)", lock); GOTO(out, rc); out: if (rc < 0) { lock_res_and_lock(lock); lock->l_flags |= LDLM_FL_FAILED; unlock_res_and_lock(lock); wake_up(&lock->l_waitq); } LDLM_LOCK_RELEASE(lock); }