Exemplo n.º 1
0
int4 gds_rundown(void)
{
	boolean_t		canceled_dbsync_timer, canceled_flush_timer, ok_to_write_pfin;
	boolean_t		have_standalone_access, ipc_deleted, err_caught;
	boolean_t		is_cur_process_ss_initiator, remove_shm, vermismatch, we_are_last_user, we_are_last_writer, is_mm;
	boolean_t		unsafe_last_writer;
	char			time_str[CTIME_BEFORE_NL + 2]; /* for GET_CUR_TIME macro */
	gd_region		*reg;
	int			save_errno, status, rc;
	int4			semval, ftok_semval, sopcnt, ftok_sopcnt;
	short			crash_count;
	sm_long_t		munmap_len;
	sgmnt_addrs		*csa;
	sgmnt_data_ptr_t	csd;
	node_local_ptr_t	cnl;
	struct shmid_ds		shm_buf;
	struct sembuf		sop[2], ftok_sop[2];
	uint4           	jnl_status;
	unix_db_info		*udi;
	jnl_private_control	*jpc;
	jnl_buffer_ptr_t	jbp;
	shm_snapshot_t		*ss_shm_ptr;
	uint4			ss_pid, onln_rlbk_pid, holder_pid;
	boolean_t		was_crit;
	boolean_t		safe_mode; /* Do not flush or take down shared memory. */
	boolean_t		bypassed_ftok = FALSE, bypassed_access = FALSE, may_bypass_ftok, inst_is_frozen,
				ftok_counter_halted,
				access_counter_halted;
	int			secshrstat;
	intrpt_state_t		prev_intrpt_state;
	DCL_THREADGBL_ACCESS;

	SETUP_THREADGBL_ACCESS;
	jnl_status = 0;
	reg = gv_cur_region;			/* Local copy */

	/* early out for cluster regions
	 * to avoid tripping the assert below.
	 * Note:
	 *	This early out is consistent with VMS.  It has been
	 *	noted that all of the gtcm assignments
	 *      to gv_cur_region should use the TP_CHANGE_REG
	 *	macro.  This would also avoid the assert problem
	 *	and should be done eventually.
	 */
	if (dba_cm == reg->dyn.addr->acc_meth)
		return EXIT_NRM;

	udi = FILE_INFO(reg);
	csa = &udi->s_addrs;
	csd = csa->hdr;
	assert(csa == cs_addrs && csd == cs_data);
	if ((reg->open) && (dba_usr == csd->acc_meth))
	{
		change_reg();
		gvusr_rundown();
		return EXIT_NRM;
	}
	/* If the process has standalone access, it has udi->grabbed_access_sem set to TRUE at this point. Note that down in a local
	 * variable as the udi->grabbed_access_sem is set to TRUE even for non-standalone access below and hence we can't rely on
	 * that later to determine if the process had standalone access or not when it entered this function.  We need to guarantee
	 * that none else access database file header when semid/shmid fields are reset.  We already have created ftok semaphore in
	 * db_init or, mu_rndwn_file and did not remove it.  So just lock it. We do it in blocking mode.
	 */
	have_standalone_access = udi->grabbed_access_sem; /* process holds standalone access */
	DEFER_INTERRUPTS(INTRPT_IN_GDS_RUNDOWN, prev_intrpt_state);
	ESTABLISH_NORET(gds_rundown_ch, err_caught);
	if (err_caught)
	{
		REVERT;
		WITH_CH(gds_rundown_ch, gds_rundown_err_cleanup(have_standalone_access), 0);
		ENABLE_INTERRUPTS(INTRPT_IN_GDS_RUNDOWN, prev_intrpt_state);
		DEBUG_ONLY(ok_to_UNWIND_in_exit_handling = FALSE);
		return EXIT_ERR;
	}
	assert(reg->open);			/* if we failed to open, dbinit_ch should have taken care of proper clean up */
	assert(!reg->opening);			/* see comment above */
	assert((dba_bg == csd->acc_meth) || (dba_mm == csd->acc_meth));
	is_mm = (dba_bg != csd->acc_meth);
	assert(!csa->hold_onto_crit || (csa->now_crit && jgbl.onlnrlbk));
	/* If we are online rollback, we should already be holding crit and should release it only at the end of this module. This
	 * is usually done by noting down csa->now_crit in a local variable (was_crit) and using it whenever we are about to
	 * grab_crit. But, there are instances (like mupip_set_journal.c) where we grab_crit but invoke gds_rundown without any
	 * preceeding rel_crit. Such code relies on the fact that gds_rundown does rel_crit unconditionally (to get locks to a known
	 * state). So, augment csa->now_crit with jgbl.onlnrlbk to track if we can rel_crit unconditionally or not in gds_rundown.
	 */
	was_crit = (csa->now_crit && jgbl.onlnrlbk);
	/* Cancel any pending flush timer for this region by this task */
	canceled_flush_timer = FALSE;
	canceled_dbsync_timer = FALSE;
	CANCEL_DB_TIMERS(reg, csa, canceled_flush_timer, canceled_dbsync_timer);
	we_are_last_user = FALSE;
	inst_is_frozen = IS_REPL_INST_FROZEN && REPL_ALLOWED(csa->hdr);
	if (!csa->persistent_freeze)
		region_freeze(reg, FALSE, FALSE, FALSE);
	if (!was_crit)
	{
		rel_crit(reg);		/* get locks to known state */
		mutex_cleanup(reg);
	}
	/* The only process that can invoke gds_rundown while holding access control semaphore is RECOVER/ROLLBACK. All the others
	 * (like MUPIP SET -FILE/MUPIP EXTEND would have invoked db_ipcs_reset() before invoking gds_rundown (from
	 * mupip_exit_handler). The only exception is when these processes encounter a terminate signal and they reach
	 * mupip_exit_handler while holding access control semaphore. Assert accordingly.
	 */
	assert(!have_standalone_access || mupip_jnl_recover || process_exiting);
	/* If we have standalone access, then ensure that a concurrent online rollback cannot be running at the same time as it
	 * needs the access control lock as well. The only expection is we are online rollback and currently running down.
	 */
	cnl = csa->nl;
	onln_rlbk_pid = cnl->onln_rlbk_pid;
	assert(!have_standalone_access || mupip_jnl_recover || !onln_rlbk_pid || !is_proc_alive(onln_rlbk_pid, 0));
	if (!have_standalone_access)
	{
		if (-1 == (ftok_semval = semctl(udi->ftok_semid, DB_COUNTER_SEM, GETVAL))) /* Check # of procs counted on FTOK */
		{
			save_errno = errno;
			assert(FALSE);
			rts_error_csa(CSA_ARG(csa) VARLSTCNT(12) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg), ERR_SYSCALL, 5,
				  RTS_ERROR_TEXT("gds_rundown SEMCTL failed to get ftok_semval"), CALLFROM, errno);
		}
		may_bypass_ftok = CAN_BYPASS(ftok_semval, csd, inst_is_frozen); /* Do we need a blocking wait? */
		/* We need to guarantee that no one else access database file header when semid/shmid fields are reset.
		 * We already have created ftok semaphore in db_init or mu_rndwn_file and did not remove it. So just lock it.
		 */
		if (!ftok_sem_lock(reg, may_bypass_ftok))
		{
			if (may_bypass_ftok)
			{	/* We did a non-blocking wait. It's ok to proceed without locking */
				bypassed_ftok = TRUE;
				holder_pid = semctl(udi->ftok_semid, DB_CONTROL_SEM, GETPID);
				if ((uint4)-1 == holder_pid)
					rts_error_csa(CSA_ARG(csa) VARLSTCNT(12) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg),
							ERR_SYSCALL, 5,
							RTS_ERROR_TEXT("gds_rundown SEMCTL failed to get holder_pid"),
							CALLFROM, errno);
				if (!IS_GTM_IMAGE) /* MUMPS processes should not flood syslog with bypass messages. */
				{
					send_msg_csa(CSA_ARG(csa) VARLSTCNT(12) ERR_RESRCINTRLCKBYPAS, 10,
						 LEN_AND_STR(gtmImageNames[image_type].imageName), process_id, LEN_AND_LIT("FTOK"),
						 REG_LEN_STR(reg), DB_LEN_STR(reg), holder_pid);
					send_msg_csa(CSA_ARG(NULL) VARLSTCNT(4) ERR_TEXT, 2,
							LEN_AND_LIT("FTOK bypassed at rundown"));
				}
			} else
			{	/* We did a blocking wait but something bad happened. */
				FTOK_TRACE(csa, csa->ti->curr_tn, ftok_ops_lock, process_id);
				rts_error_csa(CSA_ARG(csa) VARLSTCNT(4) ERR_DBFILERR, 2, DB_LEN_STR(reg));
			}
		}
		sop[0].sem_num = DB_CONTROL_SEM; sop[0].sem_op = 0;	/* Wait for 0 */
		sop[1].sem_num = DB_CONTROL_SEM; sop[1].sem_op = 1;	/* Lock */
		sopcnt = 2;
		sop[0].sem_flg = sop[1].sem_flg = SEM_UNDO | IPC_NOWAIT; /* Don't wait the first time thru */
		SEMOP(udi->semid, sop, sopcnt, status, NO_WAIT);
		if (0 != status)
		{
			save_errno = errno;
			/* Check # of processes counted on access sem. */
			if (-1 == (semval = semctl(udi->semid, DB_COUNTER_SEM, GETVAL)))
			{
				assert(FALSE);
				rts_error_csa(CSA_ARG(csa) VARLSTCNT(12) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg), ERR_SYSCALL, 5,
					  RTS_ERROR_TEXT("gds_rundown SEMCTL failed to get semval"), CALLFROM, errno);
			}
			bypassed_access = CAN_BYPASS(semval, csd, inst_is_frozen) || onln_rlbk_pid || csd->file_corrupt;
			/* Before attempting again in the blocking mode, see if the holding process is an online rollback.
			 * If so, it is likely we won't get the access control semaphore anytime soon. In that case, we
			 * are better off skipping rundown and continuing with sanity cleanup and exit.
			 */
			holder_pid = semctl(udi->semid, DB_CONTROL_SEM, GETPID);
			if ((uint4)-1 == holder_pid)
				rts_error_csa(CSA_ARG(csa) VARLSTCNT(12) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg), ERR_SYSCALL, 5,
					  RTS_ERROR_TEXT("gds_rundown SEMCTL failed to get holder_pid"), CALLFROM, errno);
			if (!bypassed_access)
			{	/* We couldn't get it in one shot-- see if we already have it */
				if (holder_pid == process_id)
				{
					send_msg_csa(CSA_ARG(csa) VARLSTCNT(5) MAKE_MSG_INFO(ERR_CRITSEMFAIL), 2, DB_LEN_STR(reg),
							ERR_RNDWNSEMFAIL);
					REVERT;
					ENABLE_INTERRUPTS(INTRPT_IN_GDS_RUNDOWN, prev_intrpt_state);
					assert(FALSE);
					return EXIT_ERR;
				}
				if (EAGAIN != save_errno)
				{
					assert(FALSE);
					rts_error_csa(CSA_ARG(csa) VARLSTCNT(12) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg),
							ERR_SYSCALL, 5,
							RTS_ERROR_TEXT("gds_rundown SEMOP on access control semaphore"),
							CALLFROM, save_errno);
				}
				sop[0].sem_flg = sop[1].sem_flg = SEM_UNDO;	/* Try again - blocking this time */
				SEMOP(udi->semid, sop, 2, status, FORCED_WAIT);
				if (-1 == status)			/* We couldn't get it at all.. */
					rts_error_csa(CSA_ARG(csa) VARLSTCNT(12) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg),
							ERR_SYSCALL, 5,
							RTS_ERROR_TEXT("gds_rundown SEMOP on access control semaphore"),
							CALLFROM, errno);
			} else if (!IS_GTM_IMAGE)
			{
				send_msg_csa(CSA_ARG(csa) VARLSTCNT(12) ERR_RESRCINTRLCKBYPAS, 10,
						LEN_AND_STR(gtmImageNames[image_type].imageName), process_id,
						LEN_AND_LIT("access control"), REG_LEN_STR(reg), DB_LEN_STR(reg), holder_pid);
				send_msg_csa(CSA_ARG(NULL) VARLSTCNT(4) ERR_TEXT, 2,
						LEN_AND_LIT("Access control bypassed at rundown"));
			}
			udi->grabbed_access_sem = !bypassed_access;
		}
	} /* else we we hold the access control semaphore and therefore have standalone access. We do not release it now - we
	   * release it later in mupip_exit_handler.c. Since we already hold the access control semaphore, we don't need the
	   * ftok semaphore and trying it could cause deadlock
	   */
	/* Note that in the case of online rollback, "udi->grabbed_access_sem" (and in turn "have_standalone_access") is TRUE.
	 * But there could be other processes still having the database open so we cannot safely reset the halted fields.
	 */
	if (have_standalone_access && !jgbl.onlnrlbk)
		csd->ftok_counter_halted = csd->access_counter_halted = FALSE;
	ftok_counter_halted = csd->ftok_counter_halted;
	access_counter_halted = csd->access_counter_halted;
	/* If we bypassed any of the semaphores, activate safe mode.
	 * Also, if the replication instance is frozen and this db has replication turned on (which means
	 * no flushes of dirty buffers to this db can happen while the instance is frozen) activate safe mode.
	 */
	ok_to_write_pfin = !(bypassed_access || bypassed_ftok || inst_is_frozen);
	safe_mode = !ok_to_write_pfin || ftok_counter_halted || access_counter_halted;
	/* At this point we are guaranteed no one else is doing a db_init/rundown as we hold the access control semaphore */
	assert(csa->ref_cnt);	/* decrement private ref_cnt before shared ref_cnt decrement. */
	csa->ref_cnt--;		/* Currently journaling logic in gds_rundown() in VMS relies on this order to detect last writer */
	assert(!csa->ref_cnt);
	--cnl->ref_cnt;
	if (memcmp(cnl->now_running, gtm_release_name, gtm_release_name_len + 1))
	{	/* VERMISMATCH condition. Possible only if DSE */
		assert(dse_running);
		vermismatch = TRUE;
	} else
		vermismatch = FALSE;
	if (-1 == shmctl(udi->shmid, IPC_STAT, &shm_buf))
	{
		save_errno = errno;
		rts_error_csa(CSA_ARG(csa) VARLSTCNT(12) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg), ERR_SYSCALL, 5,
				RTS_ERROR_TEXT("gds_rundown shmctl"), CALLFROM, save_errno);
	} else
		we_are_last_user =  (1 == shm_buf.shm_nattch) && !vermismatch && !safe_mode;
	/* recover => one user except ONLINE ROLLBACK, or standalone with frozen instance */
	assert(!have_standalone_access || we_are_last_user || jgbl.onlnrlbk || inst_is_frozen);
	if (-1 == (semval = semctl(udi->semid, DB_COUNTER_SEM, GETVAL)))
		rts_error_csa(CSA_ARG(csa) VARLSTCNT(12) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg), ERR_SYSCALL, 5,
			  RTS_ERROR_TEXT("gds_rundown SEMCTL failed to get semval"), CALLFROM, errno);
	/* There's one writer left and I am it */
	assert(reg->read_only || semval >= 0);
	unsafe_last_writer = (DB_COUNTER_SEM_INCR == semval) && (FALSE == reg->read_only) && !vermismatch;
	we_are_last_writer = unsafe_last_writer && !safe_mode;
	assert(!we_are_last_writer || !safe_mode);
	assert(!we_are_last_user || !safe_mode);
	/* recover + R/W region => one writer except ONLINE ROLLBACK, or standalone with frozen instance, leading to safe_mode */
	assert(!(have_standalone_access && !reg->read_only) || we_are_last_writer || jgbl.onlnrlbk || inst_is_frozen);
	GTM_WHITE_BOX_TEST(WBTEST_ANTIFREEZE_JNLCLOSE, we_are_last_writer, 1); /* Assume we are the last writer to invoke wcs_flu */
	if (!have_standalone_access && (-1 == (ftok_semval = semctl(udi->ftok_semid, DB_COUNTER_SEM, GETVAL))))
		rts_error_csa(CSA_ARG(csa) VARLSTCNT(12) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg), ERR_SYSCALL, 5,
			  RTS_ERROR_TEXT("gds_rundown SEMCTL failed to get ftok_semval"), CALLFROM, errno);
	if (NULL != csa->ss_ctx)
		ss_destroy_context(csa->ss_ctx);
	/* SS_MULTI: If multiple snapshots are supported, then we have to run through each of the snapshots */
	assert(1 == MAX_SNAPSHOTS);
	ss_shm_ptr = (shm_snapshot_ptr_t)SS_GETSTARTPTR(csa);
	ss_pid = ss_shm_ptr->ss_info.ss_pid;
	is_cur_process_ss_initiator = (process_id == ss_pid);
	if (ss_pid && (is_cur_process_ss_initiator || we_are_last_user))
	{
		/* Try getting snapshot crit latch. If we don't get latch, we won't hang for eternity and will skip
		 * doing the orphaned snapshot cleanup. It will be cleaned up eventually either by subsequent MUPIP
		 * INTEG or by a MUPIP RUNDOWN.
		 */
		if (ss_get_lock_nowait(reg) && (ss_pid == ss_shm_ptr->ss_info.ss_pid)
			&& (is_cur_process_ss_initiator || !is_proc_alive(ss_pid, 0)))
		{
			ss_release(NULL);
			ss_release_lock(reg);
		}
	}
	/* If cnl->donotflush_dbjnl is set, it means mupip recover/rollback was interrupted and therefore we need not flush
	 * shared memory contents to disk as they might be in an inconsistent state. Moreover, any more flushing will only cause
	 * future rollback to undo more journal records (PBLKs). In this case, we will go ahead and remove shared memory (without
	 * flushing the contents) in this routine. A reissue of the recover/rollback command will restore the database to a
	 * consistent state.
	 */
	if (!cnl->donotflush_dbjnl && !reg->read_only && !vermismatch)
	{	/* If we had an orphaned block and were interrupted, set wc_blocked so we can invoke wcs_recover. Do it ONLY
		 * if there is NO concurrent online rollback running (as we need crit to set wc_blocked)
		 */
		if (csa->wbuf_dqd && !is_mm)
		{	/* If we had an orphaned block and were interrupted, mupip_exit_handler will invoke secshr_db_clnup which
			 * will clear this field and so we should never come to gds_rundown with a non-zero wbuf_dqd. The only
			 * exception is if we are recover/rollback in which case gds_rundown (from mur_close_files) is invoked
			 * BEFORE secshr_db_clnup in mur_close_files.
			 * Note: It is NOT possible for online rollback to reach here with wbuf_dqd being non-zero. This is because
			 * the moment we apply the first PBLK, we stop all interrupts and hence can never be interrupted in
			 * wcs_wtstart or wcs_get_space. Assert accordingly.
			 */
			assert(mupip_jnl_recover && !jgbl.onlnrlbk && !safe_mode);
			if (!was_crit)
				grab_crit(reg);
			SET_TRACEABLE_VAR(cnl->wc_blocked, TRUE);
			BG_TRACE_PRO_ANY(csa, wcb_gds_rundown);
                        send_msg_csa(CSA_ARG(csa) VARLSTCNT(8) ERR_WCBLOCKED, 6, LEN_AND_LIT("wcb_gds_rundown"),
                                process_id, &csa->ti->curr_tn, DB_LEN_STR(reg));
			csa->wbuf_dqd = 0;
			wcs_recover(reg);
			BG_TRACE_PRO_ANY(csa, lost_block_recovery);
			if (!was_crit)
				rel_crit(reg);
		}
		if (JNL_ENABLED(csd) && IS_GTCM_GNP_SERVER_IMAGE)
			originator_prc_vec = NULL;
		/* If we are the last writing user, then everything must be flushed */
		if (we_are_last_writer)
		{	/* Time to flush out all of our buffers */
			assert(!safe_mode);
			if (is_mm)
			{
				MM_DBFILEXT_REMAP_IF_NEEDED(csa, reg);
				cnl->remove_shm = TRUE;
			}
			if (cnl->wc_blocked && jgbl.onlnrlbk)
			{	/* if the last update done by online rollback was not committed in the normal code-path but was
				 * completed by secshr_db_clnup, wc_blocked will be set to TRUE. But, since online rollback never
				 * invokes grab_crit (since csa->hold_onto_crit is set to TRUE), wcs_recover is never invoked. This
				 * could result in the last update never getting flushed to the disk and if online rollback happened
				 * to be the last writer then the shared memory will be flushed and removed and the last update will
				 * be lost. So, force wcs_recover if we find ourselves in such a situation. But, wc_blocked is
				 * possible only if phase1 or phase2 errors are induced using white box test cases
				 */
				assert(WB_COMMIT_ERR_ENABLED);
				wcs_recover(reg);
			}
			/* Note WCSFLU_SYNC_EPOCH ensures the epoch is synced to the journal and indirectly
			 * also ensures that the db is fsynced. We don't want to use it in the calls to
			 * wcs_flu() from t_end() and tp_tend() since we can defer it to out-of-crit there.
			 * In this case, since we are running down, we don't have any such option.
			 */
			cnl->remove_shm = wcs_flu(WCSFLU_FLUSH_HDR | WCSFLU_WRITE_EPOCH | WCSFLU_SYNC_EPOCH);
			/* Since we_are_last_writer, we should be guaranteed that wcs_flu() did not change csd, (in
			 * case of MM for potential file extension), even if it did a grab_crit().  Therefore, make
			 * sure that's true.
			 */
			assert(csd == csa->hdr);
			assert(0 == memcmp(csd->label, GDS_LABEL, GDS_LABEL_SZ - 1));
		} else if (((canceled_flush_timer && (0 > cnl->wcs_timers)) || canceled_dbsync_timer) && !inst_is_frozen)
		{	/* canceled pending db or jnl flush timers - flush database and journal buffers to disk */
			if (!was_crit)
				grab_crit(reg);
			/* we need to sync the epoch as the fact that there is no active pending flush timer implies
			 * there will be noone else who will flush the dirty buffers and EPOCH to disk in a timely fashion
			 */
			wcs_flu(WCSFLU_FLUSH_HDR | WCSFLU_WRITE_EPOCH | WCSFLU_SYNC_EPOCH);
			if (!was_crit)
				rel_crit(reg);
			assert((dba_mm == cs_data->acc_meth) || (csd == cs_data));
			csd = cs_data;	/* In case this is MM and wcs_flu() remapped an extended database, reset csd */
		}
		/* Do rundown journal processing after buffer flushes since they require jnl to be open */
		if (JNL_ENABLED(csd))
		{	/* the following tp_change_reg() is not needed due to the assert csa == cs_addrs at the beginning
			 * of gds_rundown(), but just to be safe. To be removed by 2002!! --- nars -- 2001/04/25.
			 */
			tp_change_reg();	/* call this because jnl_ensure_open checks cs_addrs rather than gv_cur_region */
			jpc = csa->jnl;
			jbp = jpc->jnl_buff;
			if (jbp->fsync_in_prog_latch.u.parts.latch_pid == process_id)
                        {
                                assert(FALSE);
                                COMPSWAP_UNLOCK(&jbp->fsync_in_prog_latch, process_id, 0, LOCK_AVAILABLE, 0);
                        }
                        if (jbp->io_in_prog_latch.u.parts.latch_pid == process_id)
                        {
                                assert(FALSE);
                                COMPSWAP_UNLOCK(&jbp->io_in_prog_latch, process_id, 0, LOCK_AVAILABLE, 0);
                        }
			if ((((NOJNL != jpc->channel) && !JNL_FILE_SWITCHED(jpc))
				|| we_are_last_writer && (0 != cnl->jnl_file.u.inode)) && ok_to_write_pfin)
			{	/* We need to close the journal file cleanly if we have the latest generation journal file open
				 *	or if we are the last writer and the journal file is open in shared memory (not necessarily
				 *	by ourselves e.g. the only process that opened the journal got shot abnormally)
				 * Note: we should not infer anything from the shared memory value of cnl->jnl_file.u.inode
				 * 	if we are not the last writer as it can be concurrently updated.
				 */
				if (!was_crit)
					grab_crit(reg);
				if (JNL_ENABLED(csd))
				{
					SET_GBL_JREC_TIME; /* jnl_ensure_open/jnl_put_jrt_pini/pfin/jnl_file_close all need it */
					/* Before writing to jnlfile, adjust jgbl.gbl_jrec_time if needed to maintain time order
					 * of jnl records. This needs to be done BEFORE the jnl_ensure_open as that could write
					 * journal records (if it decides to switch to a new journal file).
					 */
					ADJUST_GBL_JREC_TIME(jgbl, jbp);
					jnl_status = jnl_ensure_open();
					if (0 == jnl_status)
					{	/* If we_are_last_writer, we would have already done a wcs_flu() which would
						 * have written an epoch record and we are guaranteed no further updates
						 * since we are the last writer. So, just close the journal.
						 * If the freeaddr == post_epoch_freeaddr, wcs_flu may have skipped writing
						 * a pini, so allow for that.
						 */
						assert(!jbp->before_images || is_mm
						    || !we_are_last_writer || (0 != jpc->pini_addr) || jgbl.mur_extract
						    || (jpc->jnl_buff->freeaddr == jpc->jnl_buff->post_epoch_freeaddr));
						/* If we haven't written a pini, let jnl_file_close write the pini/pfin. */
						if (!jgbl.mur_extract && (0 != jpc->pini_addr))
							jnl_put_jrt_pfin(csa);
						/* If not the last writer and no pending flush timer left, do jnl flush now */
						if (!we_are_last_writer && (0 > cnl->wcs_timers))
						{
							if (SS_NORMAL == (jnl_status = jnl_flush(reg)))
							{
								assert(jbp->freeaddr == jbp->dskaddr);
								jnl_fsync(reg, jbp->dskaddr);
								assert(jbp->fsync_dskaddr == jbp->dskaddr);
							} else
							{
								send_msg_csa(CSA_ARG(csa) VARLSTCNT(9) ERR_JNLFLUSH, 2,
									JNL_LEN_STR(csd), ERR_TEXT, 2,
									RTS_ERROR_TEXT("Error with journal flush in gds_rundown"),
									jnl_status);
								assert(NOJNL == jpc->channel);/* jnl file lost has been triggered */
								/* In this routine, all code that follows from here on does not
								 * assume anything about the journaling characteristics of this
								 * database so it is safe to continue execution even though
								 * journaling got closed in the middle.
								 */
							}
						}
						jnl_file_close(reg, we_are_last_writer, FALSE);
					} else
						send_msg_csa(CSA_ARG(csa) VARLSTCNT(6) jnl_status, 4, JNL_LEN_STR(csd),
								DB_LEN_STR(reg));
				}
				if (!was_crit)
					rel_crit(reg);
			}
		}
		if (we_are_last_writer)			/* Flush the fileheader last and harden the file to disk */
		{
			if (!was_crit)
				grab_crit(reg);			/* To satisfy crit requirement in fileheader_sync() */
			memset(csd->machine_name, 0, MAX_MCNAMELEN); /* clear the machine_name field */
			if (!have_standalone_access && we_are_last_user)
			{	/* mupip_exit_handler will do this after mur_close_file */
				csd->semid = INVALID_SEMID;
				csd->shmid = INVALID_SHMID;
				csd->gt_sem_ctime.ctime = 0;
				csd->gt_shm_ctime.ctime = 0;
			}
			fileheader_sync(reg);
			if (!was_crit)
				rel_crit(reg);
			if (!is_mm)
			{
				GTM_DB_FSYNC(csa, udi->fd, rc);		/* Sync it all */
				if (-1 == rc)
				{
					rts_error_csa(CSA_ARG(csa) VARLSTCNT(9) ERR_DBFILERR, 2, DB_LEN_STR(reg),
						  ERR_TEXT, 2, RTS_ERROR_TEXT("Error during file sync at close"), errno);
				}
			} else
			{	/* Now do final MM file sync before exit */
				assert(csa->ti->total_blks == csa->total_blks);
				#ifdef _AIX
				GTM_DB_FSYNC(csa, udi->fd, rc);
				if (-1 == rc)
				#else
				if (-1 == MSYNC((caddr_t)csa->db_addrs[0], (caddr_t)csa->db_addrs[1]))
				#endif
				{
					rts_error_csa(CSA_ARG(csa) VARLSTCNT(9) ERR_DBFILERR, 2, DB_LEN_STR(reg),
						  ERR_TEXT, 2, RTS_ERROR_TEXT("Error during file sync at close"), errno);
				}
			}
		} else if (unsafe_last_writer && !cnl->lastwriterbypas_msg_issued)
		{
			send_msg_csa(CSA_ARG(csa) VARLSTCNT(4) ERR_LASTWRITERBYPAS, 2, DB_LEN_STR(reg));
			cnl->lastwriterbypas_msg_issued = TRUE;
		}
	} /* end if (!reg->read_only && !cnl->donotflush_dbjnl) */
	/* We had canceled all db timers at start of rundown. In case as part of rundown (wcs_flu above), we had started
	 * any timers, cancel them BEFORE setting reg->open to FALSE (assert in wcs_clean_dbsync relies on this).
	 */
	CANCEL_DB_TIMERS(reg, csa, canceled_flush_timer, canceled_dbsync_timer);
	if (reg->read_only && we_are_last_user && !have_standalone_access && cnl->remove_shm)
	{	/* mupip_exit_handler will do this after mur_close_file */
		db_ipcs.semid = INVALID_SEMID;
		db_ipcs.shmid = INVALID_SHMID;
		db_ipcs.gt_sem_ctime = 0;
		db_ipcs.gt_shm_ctime = 0;
		db_ipcs.fn_len = reg->dyn.addr->fname_len;
		memcpy(db_ipcs.fn, reg->dyn.addr->fname, reg->dyn.addr->fname_len);
		db_ipcs.fn[reg->dyn.addr->fname_len] = 0;
 		/* request gtmsecshr to flush. read_only cannot flush itself */
		WAIT_FOR_REPL_INST_UNFREEZE_SAFE(csa);
		if (!csa->read_only_fs)
		{
			secshrstat = send_mesg2gtmsecshr(FLUSH_DB_IPCS_INFO, 0, (char *)NULL, 0);
			if (0 != secshrstat)
				rts_error_csa(CSA_ARG(csa) VARLSTCNT(8) ERR_DBFILERR, 2, DB_LEN_STR(reg),
					  ERR_TEXT, 2, RTS_ERROR_TEXT("gtmsecshr failed to update database file header"));
		}
	}
	/* Done with file now, close it */
	CLOSEFILE_RESET(udi->fd, rc);	/* resets "udi->fd" to FD_INVALID */
	if (-1 == rc)
	{
		rts_error_csa(CSA_ARG(csa) VARLSTCNT(9) ERR_DBFILERR, 2, DB_LEN_STR(reg),
			  ERR_TEXT, 2, LEN_AND_LIT("Error during file close"), errno);
	}
	/* Unmap storage if mm mode but only the part that is not the fileheader (so shows up in dumps) */
#	if !defined(_AIX)
	if (is_mm && (NULL != csa->db_addrs[0]))
	{
		assert(csa->db_addrs[1] > csa->db_addrs[0]);
		munmap_len = (sm_long_t)(csa->db_addrs[1] - csa->db_addrs[0]);
		if (0 < munmap_len)
			munmap((caddr_t)(csa->db_addrs[0]), (size_t)(munmap_len));
	}
#	endif
	/* Detach our shared memory while still under lock so reference counts will be correct for the next process to run down
	 * this region. In the process also get the remove_shm status from node_local before detaching.
	 * If cnl->donotflush_dbjnl is TRUE, it means we can safely remove shared memory without compromising data
	 * integrity as a reissue of recover will restore the database to a consistent state.
	 */
	remove_shm = !vermismatch && (cnl->remove_shm || cnl->donotflush_dbjnl);
	/* We are done with online rollback on this region. Indicate to other processes by setting the onln_rlbk_pid to 0.
	 * Do it before releasing crit (t_end relies on this ordering when accessing cnl->onln_rlbk_pid).
	 */
	if (jgbl.onlnrlbk)
		cnl->onln_rlbk_pid = 0;
	rel_crit(reg); /* Since we are about to detach from the shared memory, release crit and reset onln_rlbk_pid */
	/* If we had skipped flushing journal and database buffers due to a concurrent online rollback, increment the counter
	 * indicating that in the shared memory so that online rollback can report the # of such processes when it shuts down.
	 * The same thing is done for both FTOK and access control semaphores when there are too many MUMPS processes.
	 */
	if (safe_mode) /* indicates flushing was skipped */
	{
		if (bypassed_access)
			cnl->dbrndwn_access_skip++; /* Access semaphore can be bypassed during online rollback */
		if (bypassed_ftok)
			cnl->dbrndwn_ftok_skip++;
	}
	if (jgbl.onlnrlbk)
		csa->hold_onto_crit = FALSE;
	GTM_WHITE_BOX_TEST(WBTEST_HOLD_SEM_BYPASS, cnl->wbox_test_seq_num, 0);
	status = shmdt((caddr_t)cnl);
	csa->nl = NULL; /* dereferencing nl after detach is not right, so we set it to NULL so that we can test before dereference*/
	/* Note that although csa->nl is NULL, we use CSA_ARG(csa) below (not CSA_ARG(NULL)) to be consistent with similar
	 * usages before csa->nl became NULL. The "is_anticipatory_freeze_needed" function (which is in turn called by the
	 * CHECK_IF_FREEZE_ON_ERROR_NEEDED macro) does a check of csa->nl before dereferencing shared memory contents so
	 * we are safe passing "csa".
	 */
	if (-1 == status)
		send_msg_csa(CSA_ARG(csa) VARLSTCNT(9) ERR_DBFILERR, 2, DB_LEN_STR(reg), ERR_TEXT, 2,
				LEN_AND_LIT("Error during shmdt"), errno);
	REMOVE_CSA_FROM_CSADDRSLIST(csa);	/* remove "csa" from list of open regions (cs_addrs_list) */
	reg->open = FALSE;
	/* If file is still not in good shape, die here and now before we get rid of our storage */
	assertpro(0 == csa->wbuf_dqd);
	ipc_deleted = FALSE;
	/* If we are the very last user, remove shared storage id and the semaphores */
	if (we_are_last_user)
	{	/* remove shared storage, only if last writer to rundown did a successful wcs_flu() */
		assert(!vermismatch);
		if (remove_shm)
		{
			ipc_deleted = TRUE;
			if (0 != shm_rmid(udi->shmid))
				rts_error_csa(CSA_ARG(csa) VARLSTCNT(8) ERR_DBFILERR, 2, DB_LEN_STR(reg),
					ERR_TEXT, 2, RTS_ERROR_TEXT("Unable to remove shared memory"));
			/* Note that we no longer have a new shared memory. Currently only used/usable for standalone rollback. */
			udi->new_shm = FALSE;
			/* mupip recover/rollback don't release the semaphore here, but do it later in db_ipcs_reset (invoked from
			 * mur_close_files())
			 */
			if (!have_standalone_access)
			{
				if (0 != sem_rmid(udi->semid))
					rts_error_csa(CSA_ARG(csa) VARLSTCNT(8) ERR_DBFILERR, 2, DB_LEN_STR(reg),
						      ERR_TEXT, 2, RTS_ERROR_TEXT("Unable to remove semaphore"));
				udi->new_sem = FALSE;			/* Note that we no longer have a new semaphore */
				udi->grabbed_access_sem = FALSE;
				udi->counter_acc_incremented = FALSE;
			}
		} else if (is_src_server || is_updproc)
		{
			gtm_putmsg_csa(CSA_ARG(csa) VARLSTCNT(6) ERR_DBRNDWNWRN, 4, DB_LEN_STR(reg), process_id, process_id);
			send_msg_csa(CSA_ARG(csa) VARLSTCNT(6) ERR_DBRNDWNWRN, 4, DB_LEN_STR(reg), process_id, process_id);
		} else
			send_msg_csa(CSA_ARG(csa) VARLSTCNT(6) ERR_DBRNDWNWRN, 4, DB_LEN_STR(reg), process_id, process_id);
	} else
	{
		assert(!have_standalone_access || jgbl.onlnrlbk || safe_mode);
		if (!jgbl.onlnrlbk && !have_standalone_access)
		{ 	/* If we were writing, get rid of our writer access count semaphore */
			if (!reg->read_only)
			{
				if (!access_counter_halted)
				{
					save_errno = do_semop(udi->semid, DB_COUNTER_SEM, -DB_COUNTER_SEM_INCR, SEM_UNDO);
					if (0 != save_errno)
						rts_error_csa(CSA_ARG(csa) VARLSTCNT(12) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg),
								ERR_SYSCALL, 5,
								RTS_ERROR_TEXT("gds_rundown access control semaphore decrement"),
								CALLFROM, save_errno);
				}
				udi->counter_acc_incremented = FALSE;
			}
			assert(safe_mode || !bypassed_access);
			/* Now remove the rundown lock */
			if (!bypassed_access)
			{
				if (0 != (save_errno = do_semop(udi->semid, DB_CONTROL_SEM, -1, SEM_UNDO)))
					rts_error_csa(CSA_ARG(csa) VARLSTCNT(12) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg),
							ERR_SYSCALL, 5,
							RTS_ERROR_TEXT("gds_rundown access control semaphore release"),
							CALLFROM, save_errno);
				udi->grabbed_access_sem = FALSE;
			}
		} /* else access control semaphore will be released in db_ipcs_reset */
	}
	if (!have_standalone_access)
	{
		if (bypassed_ftok)
		{
			if (!ftok_counter_halted)
				if (0 != (save_errno = do_semop(udi->ftok_semid, DB_COUNTER_SEM, -DB_COUNTER_SEM_INCR, SEM_UNDO)))
					rts_error_csa(CSA_ARG(csa) VARLSTCNT(4) ERR_DBFILERR, 2, DB_LEN_STR(reg));
		} else if (!ftok_sem_release(reg, !ftok_counter_halted, FALSE))
		{
			FTOK_TRACE(csa, csa->ti->curr_tn, ftok_ops_release, process_id);
			rts_error_csa(CSA_ARG(csa) VARLSTCNT(4) ERR_DBFILERR, 2, DB_LEN_STR(reg));
		}
		udi->grabbed_ftok_sem = FALSE;
		udi->counter_ftok_incremented = FALSE;
	}
	ENABLE_INTERRUPTS(INTRPT_IN_GDS_RUNDOWN, prev_intrpt_state);
	if (!ipc_deleted)
	{
		GET_CUR_TIME(time_str);
		if (is_src_server)
			gtm_putmsg_csa(CSA_ARG(csa) VARLSTCNT(8) ERR_IPCNOTDEL, 6, CTIME_BEFORE_NL, time_str,
				LEN_AND_LIT("Source server"), REG_LEN_STR(reg));
		if (is_updproc)
			gtm_putmsg_csa(CSA_ARG(csa) VARLSTCNT(8) ERR_IPCNOTDEL, 6, CTIME_BEFORE_NL, time_str,
				LEN_AND_LIT("Update process"), REG_LEN_STR(reg));
		if (mupip_jnl_recover && (!jgbl.onlnrlbk || !we_are_last_user))
		{
			gtm_putmsg_csa(CSA_ARG(csa) VARLSTCNT(8) ERR_IPCNOTDEL, 6, CTIME_BEFORE_NL, time_str,
				LEN_AND_LIT("Mupip journal process"), REG_LEN_STR(reg));
			send_msg_csa(CSA_ARG(csa) VARLSTCNT(8) ERR_IPCNOTDEL, 6, CTIME_BEFORE_NL, time_str,
				LEN_AND_LIT("Mupip journal process"), REG_LEN_STR(reg));
		}
	}
	REVERT;
	return EXIT_NRM;
}
Exemplo n.º 2
0
int	mur_forward_multi_proc(reg_ctl_list *rctl)
{
	boolean_t		multi_proc, this_reg_stuck, release_latch, ok_to_play;
	boolean_t		cancelled_dbsync_timer, cancelled_timer;
	reg_ctl_list		*rctl_top, *prev_rctl;
	jnl_ctl_list		*jctl;
	gd_region		*reg;
	sgmnt_addrs		*csa;
	seq_num 		rec_token_seq;
	jnl_tm_t		rec_time;
	enum broken_type	recstat;
	jnl_record		*rec;
	enum jnl_record_type	rectype;
	char			errstr[256];
	int			i, rctl_index, save_errno, num_procs_stuck, num_reg_stuck;
	uint4			status, regcnt_stuck, num_partners, start_hrtbt_cntr;
	forw_multi_struct	*forw_multi;
	shm_forw_multi_t	*sfm;
	multi_struct 		*multi;
	jnl_tm_t		adjusted_resolve_time;
	shm_reg_ctl_t		*shm_rctl_start, *shm_rctl, *first_shm_rctl;
	size_t			shm_size, reccnt, copy_size;
	int4			*size_ptr;
	char			*shmPtr; /* not using "shm_ptr" since it is already used in an AIX include file */
	int			shmid;
	multi_proc_shm_hdr_t	*mp_hdr;	/* Pointer to "multi_proc_shm_hdr_t" structure in shared memory */

	status = 0;
	/* Although we made sure the # of tasks is the same as the # of processes forked off (in the "gtm_multi_proc"
	 * invocation in "mur_forward"), it is possible one of the forked process finishes one invocation of
	 * "mur_forward_multi_proc" before even another forked process gets assigned one task in "gtm_multi_proc_helper".
	 * In this case, we would be invoked more than once. But the first invocation would have done all the needed stuff
	 * so return for later invocations.
	 */
	if (mur_forward_multi_proc_done)
		return 0;
	mur_forward_multi_proc_done = TRUE;
	/* Note: "rctl" is unused. But cannot avoid passing it since "gtm_multi_proc" expects something */
	prev_rctl = NULL;
	rctl_start = NULL;
	adjusted_resolve_time = murgbl.adjusted_resolve_time;
	assert(0 == murgbl.regcnt_remaining);
	multi_proc = multi_proc_in_use;	/* cache value in "local" to speed up access inside loops below */
	if (multi_proc)
	{
		mp_hdr = multi_proc_shm_hdr;
		shm_rctl_start = mur_shm_hdr->shm_rctl_start;
		if (jgbl.onlnrlbk)
		{
			for (rctl = mur_ctl, rctl_top = mur_ctl + murgbl.reg_total; rctl < rctl_top; rctl++)
			{
				assert(rctl->csa->hold_onto_crit);	/* would have been set in parent process */
				rctl->csa->hold_onto_crit = FALSE;	/* reset since we dont own this region */
				assert(rctl->csa->now_crit);		/* would have been set in parent process */
				rctl->csa->now_crit = FALSE;		/* reset since we dont own this region */
			}
		}
		START_HEARTBEAT_IF_NEEDED; /* heartbeat timer needed later (in case not already started by "gtm_multi_proc") */
	}
	first_shm_rctl = NULL;
	/* Phase1 of forward recovery starts */
	for (rctl = mur_ctl, rctl_top = mur_ctl + murgbl.reg_total; rctl < rctl_top; rctl++)
	{
		/* Check if "rctl" is available for us or if some other concurrent process has taken it */
		if (multi_proc)
		{
			rctl_index = rctl - &mur_ctl[0];
			shm_rctl = &shm_rctl_start[rctl_index];
			if (shm_rctl->owning_pid)
			{
				assert(process_id != shm_rctl->owning_pid);
				continue;
			}
			GRAB_MULTI_PROC_LATCH_IF_NEEDED(release_latch);
			assert(release_latch);
			for ( ; rctl < rctl_top; rctl++, shm_rctl++)
			{
				if (shm_rctl->owning_pid)
				{
					assert(process_id != shm_rctl->owning_pid);
					continue;
				}
				shm_rctl->owning_pid = process_id;	/* Declare ownership */
				rctl->this_pid_is_owner = TRUE;
				if (jgbl.onlnrlbk)
				{	/* This is an online rollback and crit was grabbed on all regions by the parent rollback
					 * process. But this child process now owns this region and does the actual rollback on
					 * this region so borrow crit for the duration of this child process.
					 */
					csa = rctl->csa;
					csa->hold_onto_crit = TRUE;
					csa->now_crit = TRUE;
					assert(csa->nl->in_crit == mp_hdr->parent_pid);
					csa->nl->in_crit = process_id;
					assert(csa->nl->onln_rlbk_pid == mp_hdr->parent_pid);
					csa->nl->onln_rlbk_pid = process_id;
				}
				if (NULL == first_shm_rctl)
					first_shm_rctl = shm_rctl;
				break;
			}
			REL_MULTI_PROC_LATCH_IF_NEEDED(release_latch);
			if (rctl >= rctl_top)
			{
				assert(rctl == rctl_top);
				break;
			}
			/* Set key to print this rctl'ss region-name as prefix in case this forked off process prints any output */
			MUR_SET_MULTI_PROC_KEY(rctl, multi_proc_key);
#			ifdef MUR_DEBUG
			fprintf(stderr, "pid = %d : Owns region %s\n", process_id, multi_proc_key);
#			endif
		} else
			rctl->this_pid_is_owner = TRUE;
		if (mur_options.forward)
		{
			assert(NULL == rctl->jctl_turn_around);
			jctl = rctl->jctl = rctl->jctl_head;
			assert(jctl->reg_ctl == rctl);
			jctl->rec_offset = JNL_HDR_LEN;
			jnl_fence_ctl.fence_list = JNL_FENCE_LIST_END; /* initialized to reflect journaling is not enabled */
			if (mur_options.rollback)
				jgbl.mur_jrec_seqno = jctl->jfh->start_seqno;
		} else
		{
			jctl = rctl->jctl = (NULL == rctl->jctl_turn_around) ? rctl->jctl_head : rctl->jctl_turn_around;
			assert(jctl->reg_ctl == rctl);
			jctl->rec_offset = jctl->turn_around_offset;
			jgbl.mur_jrec_seqno = jctl->turn_around_seqno;
			assert((NULL != rctl->jctl_turn_around) || (0 == jctl->rec_offset));
		}
		if (mur_options.rollback)
		{
			if (murgbl.consist_jnl_seqno < jgbl.mur_jrec_seqno)
			{
				/* Assert that murgbl.losttn_seqno is never lesser than jgbl.mur_jrec_seqno (the turnaround
				 * point seqno) as this is what murgbl.consist_jnl_seqno is going to be set to and will
				 * eventually be the post-rollback seqno. If this condition is violated, the result of the
				 * recovery is a compromised database (the file header will indicate a Region Seqno which
				 * is not necessarily correct since seqnos prior to it might be absent in the database).
				 * Therefore, this is an out-of-design situation with respect to rollback and so stop it.
				 */
				assert(murgbl.losttn_seqno >= jgbl.mur_jrec_seqno);
				murgbl.consist_jnl_seqno = jgbl.mur_jrec_seqno;
			}
			assert(murgbl.consist_jnl_seqno <= murgbl.losttn_seqno);
		}
		if (mur_options.update || mur_options.extr[GOOD_TN])
		{
			reg = rctl->gd;
			gv_cur_region = reg;
			tp_change_reg();	/* note : sets cs_addrs to non-NULL value even if gv_cur_region->open is FALSE
						 * (cs_data could still be NULL). */
			rctl->csa = cs_addrs;
			cs_addrs->miscptr = (void *)rctl;
			rctl->csd = cs_data;
			rctl->sgm_info_ptr = cs_addrs->sgm_info_ptr;
			assert(!reg->open || (NULL != cs_addrs->dir_tree));
			gv_target = cs_addrs->dir_tree;
		}
		jctl->after_end_of_data = FALSE;
		status = mur_next(jctl, jctl->rec_offset);
		assert(ERR_JNLREADEOF != status);	/* cannot get EOF at start of forward processing */
		if (SS_NORMAL != status)
			goto finish;
		PRINT_VERBOSE_STAT(jctl, "mur_forward:at the start");
		rctl->process_losttn = FALSE;
		/* Any multi-region TP transaction will be processed as multiple single-region TP transactions up
		 * until the tp-resolve-time is reached. From then on, they will be treated as one multi-region TP
		 * transaction. This is needed for proper lost-tn determination (any multi-region transaction that
		 * gets played in a region AFTER it has already encountered a broken tn should treat this as a lost tn).
		 */
		do
		{
			if (multi_proc && IS_FORCED_MULTI_PROC_EXIT(mp_hdr))
			{	/* We are at a logical point. So exit if signaled by parent */
				status = ERR_FORCEDHALT;
				goto finish;
			}
			assert(jctl == rctl->jctl);
			rec = rctl->mur_desc->jnlrec;
			rec_time = rec->prefix.time;
			if (rec_time > mur_options.before_time)
				break;	/* Records after -BEFORE_TIME do not go to extract or losttrans or brkntrans files */
			if (rec_time < mur_options.after_time)
			{
				status = mur_next_rec(&jctl);
				continue; /* Records before -AFTER_TIME do not go to extract or losttrans or brkntrans files */
			}
			if (rec_time >= adjusted_resolve_time)
				break;	/* Records after this adjusted resolve_time will be processed below in phase2 */
			/* Note: Since we do hashtable token processing only for records from tp_resolve_time onwards,
			 * it is possible that if we encounter any broken transactions here we wont know they are broken
			 * but will play them as is. That is unavoidable. Specify -SINCE_TIME (for -BACKWARD rollback/recover)
			 * and -VERIFY (for -FORWARD rollback/recover) to control tp_resolve_time (and in turn more
			 * effective broken tn determination).
			 */
			status = mur_forward_play_cur_jrec(rctl);
			if (SS_NORMAL != status)
				break;
			status = mur_next_rec(&jctl);
		} while (SS_NORMAL == status);
		CHECK_IF_EOF_REACHED(rctl, status); /* sets rctl->forw_eof_seen if needed; resets "status" to SS_NORMAL */
		if (SS_NORMAL != status)
		{	/* ERR_FILENOTCREATE is possible from "mur_cre_file_extfmt" OR	ERR_FORCEDHALT is possible
			 * from "mur_forward_play_cur_jrec". No other errors are known to occur here. Assert accordingly.
			 */
			assert((ERR_FILENOTCREATE == status) || (ERR_FORCEDHALT == status));
			goto finish;
		}
		if (rctl->forw_eof_seen)
		{
			PRINT_VERBOSE_STAT(jctl, "mur_forward:Reached EOF before tp_resolve_time");
			continue;	/* Reached EOF before even getting to tp_resolve_time.
					 * Do not even consider region for next processing loop */
		}
		rctl->last_tn = 0;
		murgbl.regcnt_remaining++;	/* # of regions participating in recovery at this point */
		if (NULL == rctl_start)
			rctl_start = rctl;
		if (NULL != prev_rctl)
		{
			prev_rctl->next_rctl = rctl;
			rctl->prev_rctl = prev_rctl;
		}
		prev_rctl = rctl;
		assert(murgbl.ok_to_update_db || !rctl->db_updated);
		PRINT_VERBOSE_STAT(jctl, "mur_forward:at tp_resolve_time");
	}
	if (multi_proc)
		multi_proc_key = NULL;	/* reset key until it can be set to rctl's region-name again */
	/* Note that it is possible for rctl_start to be NULL at this point. That is there is no journal record in any region
	 * AFTER the calculated tp-resolve-time. This is possible if for example -AFTER_TIME was used and has a time later
	 * than any journal record in all journal files. If rctl_start is NULL, prev_rctl should also be NULL and vice versa.
	 */
	if (NULL != rctl_start)
	{
		assert(NULL != prev_rctl);
		prev_rctl->next_rctl = rctl_start;
		rctl_start->prev_rctl = prev_rctl;
	}
	rctl = rctl_start;
	regcnt_stuck = 0; /* # of regions we are stuck in waiting for other regions to resolve a multi-region TP transaction */
	assert((NULL == rctl) || (NULL == rctl->forw_multi));
	gv_cur_region = NULL;	/* clear out any previous value to ensure gv_cur_region/cs_addrs/cs_data
				 * all get set in sync by the MUR_CHANGE_REG macro below.
				 */
	/* Phase2 of forward recovery starts */
	while (NULL != rctl)
	{	/* while there is at least one region remaining with unprocessed journal records */
		assert(NULL != rctl_start);
		assert(0 < murgbl.regcnt_remaining);
		if (NULL != rctl->forw_multi)
		{	/* This region's current journal record is part of a TP transaction waiting for other regions */
			regcnt_stuck++;
			assert(regcnt_stuck <= murgbl.regcnt_remaining);
			if (regcnt_stuck == murgbl.regcnt_remaining)
			{
				assertpro(multi_proc_in_use); /* Else : Out-of-design situation. Stuck in ALL regions. */
				/* Check one last time if all regions are stuck waiting for another process to resolve the
				 * multi-region TP transaction. If so, wait in a sleep loop. If not, we can proceed.
				 */
				rctl = rctl_start;
				start_hrtbt_cntr = heartbeat_counter;
				do
				{
					if (IS_FORCED_MULTI_PROC_EXIT(mp_hdr))
					{	/* We are at a logical point. So exit if signaled by parent */
						status = ERR_FORCEDHALT;
						goto finish;
					}
					forw_multi = rctl->forw_multi;
					assert(NULL != forw_multi);
					sfm = forw_multi->shm_forw_multi;
					assert(NULL != sfm);
					assert(sfm->num_reg_seen_forward <= sfm->num_reg_seen_backward);
#					ifdef MUR_DEBUG
					fprintf(stderr, "Pid = %d : Line %d : token = %llu : forward = %d : backward = %d\n",
						process_id, __LINE__, (long long int)sfm->token,
						sfm->num_reg_seen_forward, sfm->num_reg_seen_backward);
#					endif
					if (sfm->num_reg_seen_forward == sfm->num_reg_seen_backward)
					{	/* We are no longer stuck in this region */
						assert(!forw_multi->no_longer_stuck);
						forw_multi->no_longer_stuck = TRUE;
						break;
					}
					rctl = rctl->next_rctl;	/* Move on to the next available region */
					assert(NULL != rctl);
					if (rctl == rctl_start)
					{	/* We went through all regions once and are still stuck.
						 * Sleep until at leat TWO heartbeats have elapsed after which check for deadlock.
						 * Do this only in the child process that owns the FIRST region in the region list.
						 * This way we dont have contention for the GRAB_MULTI_PROC_LATCH from
						 * all children at more or less the same time.
						 */
						if ((rctl == mur_ctl) && (heartbeat_counter > (start_hrtbt_cntr + 2)))
						{	/* Check if all processes are stuck for a while. If so assertpro */
							GRAB_MULTI_PROC_LATCH_IF_NEEDED(release_latch);
							assert(release_latch);
							shm_rctl_start = mur_shm_hdr->shm_rctl_start;
							num_reg_stuck = 0;
							for (i = 0; i < murgbl.reg_total; i++)
							{
								shm_rctl = &shm_rctl_start[i];
								sfm = shm_rctl->shm_forw_multi;
								if (NULL != sfm)
								{
									if (sfm->num_reg_seen_forward != sfm->num_reg_seen_backward)
										num_reg_stuck++;
								}
							}
							REL_MULTI_PROC_LATCH_IF_NEEDED(release_latch);
							/* If everyone is stuck at this point, it is an out-of-design situation */
							assertpro(num_reg_stuck < murgbl.reg_total);
							start_hrtbt_cntr = heartbeat_counter;
						} else
						{	/* Sleep and recheck if any region we are stuck in got resolved.
							 * To minimize time spent sleeping, we just yield our timeslice.
							 */
							rel_quant();
							continue;
						}
					}
				} while (TRUE);
			} else
			{
				rctl = rctl->next_rctl;	/* Move on to the next available region */
				assert(NULL != rctl);
				continue;
			}
		}
		regcnt_stuck = 0;	/* restart the counter now that we found at least one non-stuck region */
		MUR_CHANGE_REG(rctl);
		jctl = rctl->jctl;
		this_reg_stuck = FALSE;
		for ( status = SS_NORMAL; SS_NORMAL == status; )
		{
			if (multi_proc && IS_FORCED_MULTI_PROC_EXIT(mp_hdr))
			{	/* We are at a logical point. So exit if signaled by parent */
				status = ERR_FORCEDHALT;
				goto finish;
			}
			assert(jctl == rctl->jctl);
			rec = rctl->mur_desc->jnlrec;
			rec_time = rec->prefix.time;
			if (rec_time > mur_options.before_time)
				break;	/* Records after -BEFORE_TIME do not go to extract or losttrans or brkntrans files */
			assert((rec_time >= adjusted_resolve_time) || (mur_options.notncheck && !mur_options.verify));
			assert((0 == mur_options.after_time) || (mur_options.forward && !rctl->db_updated));
			if (rec_time < mur_options.after_time)
			{
				status = mur_next_rec(&jctl);
				continue; /* Records before -AFTER_TIME do not go to extract or losttrans or brkntrans files */
			}
			/* Check if current journal record can be played right away or need to wait for corresponding journal
			 * records from other participating TP regions to be reached. A non-TP or ZTP transaction can be played
			 * without issues (i.e. has no dependencies with any other regions). A single-region TP transaction too
			 * falls in the same category. A multi-region TP transaction needs to wait until all participating regions
			 * have played all journal records BEFORE this TP in order to ensure recover plays records in the exact
			 * same order that GT.M performed them in.
			 */
			/* If FENCE_NONE is specified, we would not have maintained any multi hashtable in mur_back_process for
			 * broken transaction processing. So we process multi-region TP transactions as multiple single-region
			 * TP transactions in forward phase.
			 */
			if (FENCE_NONE != mur_options.fences)
			{
				rectype = (enum jnl_record_type)rec->prefix.jrec_type;
				if (IS_TP(rectype) && IS_TUPD(rectype))
				{
					assert(IS_SET_KILL_ZKILL_ZTWORM_LGTRIG_ZTRIG(rectype));
					assert(&rec->jrec_set_kill.num_participants == &rec->jrec_ztworm.num_participants);
					assert(&rec->jrec_set_kill.num_participants == &rec->jrec_lgtrig.num_participants);
					num_partners = rec->jrec_set_kill.num_participants;
					assert(0 < num_partners);
					if (1 < num_partners)
					{
						this_reg_stuck = TRUE;
						assert(&rec->jrec_set_kill.update_num == &rec->jrec_ztworm.update_num);
						assert(&rec->jrec_set_kill.update_num == &rec->jrec_lgtrig.update_num);
					}
				}
			}
			if (this_reg_stuck)
			{
				rec_token_seq = GET_JNL_SEQNO(rec);
				MUR_FORW_TOKEN_LOOKUP(forw_multi, rec_token_seq, rec_time);
				if (NULL != forw_multi)
				{	/* This token has already been seen in another region in forward processing.
					 * Add current region as well. If all regions have been resolved, then play
					 * the entire transaction maintaining the exact same order of updates within.
					 */
					if (!forw_multi->no_longer_stuck)
						MUR_FORW_TOKEN_ONE_MORE_REG(forw_multi, rctl);
				} else
				{	/* First time we are seeing this token in forward processing. Check if this
					 * has already been determined to be a broken transaction.
					 */
					recstat = GOOD_TN;
					multi = NULL;
					if (IS_REC_POSSIBLY_BROKEN(rec_time, rec_token_seq))
					{
						multi = MUR_TOKEN_LOOKUP(rec_token_seq, rec_time, TPFENCE);
						if ((NULL != multi) && (0 < multi->partner))
							recstat = BROKEN_TN;
					}
					MUR_FORW_TOKEN_ADD(forw_multi, rec_token_seq, rec_time, rctl, num_partners,
								recstat, multi);
				}
				/* Check that "tabent" field has been initialized above (by either the MUR_FORW_TOKEN_LOOKUP
				 * or MUR_FORW_TOKEN_ADD macros). This is relied upon by "mur_forward_play_multireg_tp" below.
				 */
				assert(NULL != forw_multi->u.tabent);
				assert(forw_multi->num_reg_seen_forward <= forw_multi->num_reg_seen_backward);
				if (multi_proc)
				{
					sfm = forw_multi->shm_forw_multi;
					ok_to_play = (NULL == sfm) || (sfm->num_reg_seen_forward == sfm->num_reg_seen_backward);
				} else
					ok_to_play = (forw_multi->num_reg_seen_forward == forw_multi->num_reg_seen_backward);
				assert(ok_to_play || !forw_multi->no_longer_stuck);
				if (ok_to_play )
				{	/* We have enough information to proceed with playing this multi-region TP in
					 * forward processing (even if we might not have seen all needed regions). Now play it.
					 * Note that the TP could be BROKEN_TN or GOOD_TN. The callee handles it.
					 */
					assert(forw_multi == rctl->forw_multi);
					status = mur_forward_play_multireg_tp(forw_multi, rctl);
					this_reg_stuck = FALSE;
					/* Note that as part of playing the TP transaction, we could have reached
					 * the EOF of rctl. In this case, we need to break out of the loop.
					 */
					if ((SS_NORMAL != status) || rctl->forw_eof_seen)
						break;
					assert(NULL == rctl->forw_multi);
					assert(!dollar_tlevel);
					jctl = rctl->jctl;	/* In case the first record after the most recently processed
								 * TP transaction is in the next generation journal file */
					continue;
				}
				break;
			} else
			{
				status = mur_forward_play_cur_jrec(rctl);
				if (SS_NORMAL != status)
					break;
			}
			assert(!this_reg_stuck);
			status = mur_next_rec(&jctl);
		}
		assert((NULL == rctl->forw_multi) || this_reg_stuck);
		assert((NULL != rctl->forw_multi) || !this_reg_stuck);
		if (!this_reg_stuck)
		{	/* We are not stuck in this region (to resolve a multi-region TP).
			 * This means we are done processing all the records of this region.
			 */
			assert(NULL == rctl->forw_multi);
			if (!rctl->forw_eof_seen)
			{
				CHECK_IF_EOF_REACHED(rctl, status);
					/* sets rctl->forw_eof_seen if needed; resets "status" to SS_NORMAL */
				if (SS_NORMAL != status)
				{
					assert(ERR_FILENOTCREATE == status);
					goto finish;
				}
				assert(!dollar_tlevel);
				DELETE_RCTL_FROM_UNPROCESSED_LIST(rctl); /* since all of its records should have been processed */
			} else
			{	/* EOF was seen in rctl inside "mur_forward_play_multireg_tp" and it was removed
				 * from the unprocessed list of rctls. At the time rctl was removed, its "next_rctl"
				 * field could have been pointing to another <rctl> that has since then also been
				 * removed inside the same function. Therefore the "next_rctl" field is not reliable
				 * in this case but instead we should rely on the global variable "rctl_start" which
				 * points to the list of unprocessed rctls. Set "next_rctl" accordingly.
				 */
				rctl->next_rctl = rctl_start;
				if (ERR_JNLREADEOF == status)
					status = SS_NORMAL;
			}
			assert(rctl->deleted_from_unprocessed_list);
		}
		assert(SS_NORMAL == status);
		assert(!this_reg_stuck || !rctl->forw_eof_seen);
		assert((NULL == rctl->next_rctl) || (NULL != rctl_start));
		assert((NULL == rctl->next_rctl) || (0 < murgbl.regcnt_remaining));
		rctl = rctl->next_rctl;	/* Note : even though "rctl" could have been deleted from the doubly linked list above,
					 * rctl->next_rctl is not touched so we can still use it to get to the next element. */
	}
	assert(0 == murgbl.regcnt_remaining);
	jgbl.mur_pini_addr_reset_fnptr = NULL;	/* No more simulation of GT.M activity for any region */
	prc_vec = murgbl.prc_vec;	/* Use process-vector of MUPIP RECOVER (not any simulating GT.M process) now onwards */
	assert(0 == dollar_tlevel);
	for (rctl = mur_ctl, rctl_top = mur_ctl + murgbl.reg_total; rctl < rctl_top; rctl++)
	{
		if (!rctl->this_pid_is_owner)
		{
			assert(multi_proc_in_use);
			continue;	/* in a parallel processing environment, process only regions we own */
		}
		if (multi_proc)
		{	/* Set key to print this rctl's region-name as prefix in case this forked off process prints any output */
			MUR_SET_MULTI_PROC_KEY(rctl, multi_proc_key);
		}
		PRINT_VERBOSE_STAT(rctl->jctl, "mur_forward:at the end");
		assert(!mur_options.rollback || (0 != murgbl.consist_jnl_seqno));
		assert(mur_options.rollback || (0 == murgbl.consist_jnl_seqno));
		assert(!dollar_tlevel);	/* In case it applied a broken TUPD */
		assert(murgbl.ok_to_update_db || !rctl->db_updated);
		rctl->mur_plst = NULL;	/* reset now that simulation of GT.M updates is done */
		/* Ensure mur_block_count_correct is called if updates allowed */
		if (murgbl.ok_to_update_db && (SS_NORMAL != mur_block_count_correct(rctl)))
		{
			gtm_putmsg_csa(CSA_ARG(rctl->csa) VARLSTCNT(4) ERR_BLKCNTEDITFAIL, 2, DB_LEN_STR(rctl->gd));
			murgbl.wrn_count++;
		}
	}
finish:
	if (multi_proc)
		multi_proc_key = NULL;	/* reset key until it can be set to rctl's region-name again */
	if ((SS_NORMAL == status) && mur_options.show)
		mur_output_show();
	if (NULL != first_shm_rctl)
	{	/* Transfer needed process-private information to shared memory so parent process can later inherit this. */
		first_shm_rctl->err_cnt = murgbl.err_cnt;
		first_shm_rctl->wrn_count = murgbl.wrn_count;
		first_shm_rctl->consist_jnl_seqno = murgbl.consist_jnl_seqno;
		/* If extract files were created by this process for one or more regions, then copy that information to
		 * shared memory so parent process can use this information to do a merge sort.
		 */
		shm_rctl = mur_shm_hdr->shm_rctl_start;
		for (rctl = mur_ctl, rctl_top = mur_ctl + murgbl.reg_total; rctl < rctl_top; rctl++, shm_rctl++)
		{
			assert(multi_proc_in_use);
			if (!rctl->this_pid_is_owner)
				continue;	/* in a parallel processing environment, process only regions we own */
			/* Cancel any flush/dbsync timers by this child process for this region. This is because the
			 * child is not going to go through exit handling code (no gds_rundown etc.). And we need to
			 * clear up csa->nl->wcs_timers. (normally done by gds_rundown).
			 */
			if (NULL != rctl->csa)	/* rctl->csa can be NULL in case of "mupip journal -extract" etc. */
				CANCEL_DB_TIMERS(rctl->gd, rctl->csa, cancelled_timer, cancelled_dbsync_timer);
			reccnt = 0;
			for (size_ptr = &rctl->jnlext_multi_list_size[0], recstat = 0;
								recstat < TOT_EXTR_TYPES;
									recstat++, size_ptr++)
			{	/* Assert "extr_file_created" information is in sync between rctl and shm_rctl.
				 * This was done at the end of "mur_cre_file_extfmt".
				 */
				assert(shm_rctl->extr_file_created[recstat] == rctl->extr_file_created[recstat]);
				/* Assert that if *size_ptr is non-zero, then we better have created an extract file.
				 * Note that the converse is not true. It is possible we created a file for example to
				 * write an INCTN record but decided to not write anything because it was not a -detail
				 * type of extract. So *sizeptr could be 0 even though we created the extract file.
				 */
				assert(!*size_ptr || rctl->extr_file_created[recstat]);
				shm_rctl->jnlext_list_size[recstat] = *size_ptr;
				reccnt += *size_ptr;
			}
			assert(INVALID_SHMID == shm_rctl->jnlext_shmid);
			shm_size = reccnt * SIZEOF(jnlext_multi_t);
			/* If we are quitting because of an abnormal status OR a forced signal to terminate
			 * OR if the parent is dead (kill -9) dont bother creating shmid to communicate back with parent.
			 */
			if (mp_hdr->parent_pid != getppid())
			{
				SET_FORCED_MULTI_PROC_EXIT;	/* Also signal sibling children to stop processing */
				if (SS_NORMAL != status)
					status = ERR_FORCEDHALT;
			}
			if ((SS_NORMAL == status) && shm_size)
			{
				shmid = shmget(IPC_PRIVATE, shm_size, 0600 | IPC_CREAT);
				if (-1 == shmid)
				{
					save_errno = errno;
					SNPRINTF(errstr, SIZEOF(errstr),
						"shmget() : shmsize=0x%llx", shm_size);
					MUR_SET_MULTI_PROC_KEY(rctl, multi_proc_key);	/* to print region name prefix */
					rts_error_csa(CSA_ARG(NULL) VARLSTCNT(8)
								ERR_SYSCALL, 5, LEN_AND_STR(errstr), CALLFROM, save_errno);
				}
				shmPtr = (char *)do_shmat(shmid, 0, 0);
				if (-1 == (sm_long_t)shmPtr)
				{
					save_errno = errno;
					SNPRINTF(errstr, SIZEOF(errstr),
						"shmat() : shmid=%d shmsize=0x%llx", shmid, shm_size);
					MUR_SET_MULTI_PROC_KEY(rctl, multi_proc_key);	/* to print region name prefix */
					rts_error_csa(CSA_ARG(NULL) VARLSTCNT(8)
								ERR_SYSCALL, 5, LEN_AND_STR(errstr), CALLFROM, save_errno);
				}
				shm_rctl->jnlext_shmid = shmid;
				shm_rctl->jnlext_shm_size = shm_size;
				for (size_ptr = &rctl->jnlext_multi_list_size[0], recstat = 0;
									recstat < TOT_EXTR_TYPES;
										recstat++, size_ptr++)
				{
					shm_size = *size_ptr;
					if (shm_size)
					{
						copy_size = copy_list_to_buf(rctl->jnlext_multi_list[recstat],
												(int4)shm_size, shmPtr);
						assert(copy_size == (shm_size * SIZEOF(jnlext_multi_t)));
						shmPtr += copy_size;
					}
				}
			}
		}
	}
	mur_close_file_extfmt(IN_MUR_CLOSE_FILES_FALSE);	/* Need to flush buffered extract/losttrans/brokentrans files */
	return (int)status;
}
Exemplo n.º 3
0
void gds_rundown(void)
{
	bool			is_mm, we_are_last_user, we_are_last_writer;
	boolean_t		ipc_deleted, remove_shm, cancelled_timer, cancelled_dbsync_timer, vermismatch;
	now_t			now;	/* for GET_CUR_TIME macro */
	char			*time_ptr, time_str[CTIME_BEFORE_NL + 2]; /* for GET_CUR_TIME macro */
	gd_region		*reg;
	int			save_errno, status;
	int4			semval, ftok_semval, sopcnt, ftok_sopcnt;
	short			crash_count;
	sm_long_t		munmap_len;
	sgmnt_addrs		*csa;
	sgmnt_data_ptr_t	csd;
	struct shmid_ds		shm_buf;
	struct sembuf		sop[2], ftok_sop[2];
	uint4           	jnl_status;
	unix_db_info		*udi;
	jnl_private_control	*jpc;
	jnl_buffer_ptr_t	jbp;

	error_def(ERR_CRITSEMFAIL);
	error_def(ERR_DBCCERR);
	error_def(ERR_DBFILERR);
	error_def(ERR_DBRNDWNWRN);
	error_def(ERR_ERRCALL);
	error_def(ERR_GBLOFLOW);
	error_def(ERR_GTMASSERT);
	error_def(ERR_IPCNOTDEL);
	error_def(ERR_JNLFLUSH);
	error_def(ERR_RNDWNSEMFAIL);
	error_def(ERR_TEXT);
	error_def(ERR_WCBLOCKED);

	forced_exit = FALSE;		/* Okay, we're dying already -- let rel_crit live in peace now.
					 * If coming through a DAL, not necessarily dying. what to do then? -- nars -- 8/15/2001
					 */
	grabbed_access_sem = FALSE;
	jnl_status = 0;
	reg = gv_cur_region;			/* Local copy */

	/*
	 * early out for cluster regions
	 * to avoid tripping the assert below.
	 * Note:
	 *	This early out is consistent with VMS.  It has been
	 *	noted that all of the gtcm assignments
	 *      to gv_cur_region should use the TP_CHANGE_REG
	 *	macro.  This would also avoid the assert problem
	 *	and should be done eventually.
	 */
	if (dba_cm == reg->dyn.addr->acc_meth)
		return;

	udi = FILE_INFO(reg);
	csa = &udi->s_addrs;
	csd = csa->hdr;
	assert(csa == cs_addrs && csd == cs_data);
	if ((reg->open) && (dba_usr == csd->acc_meth))
	{
		change_reg();
		gvusr_rundown();
		return;
	}
	ESTABLISH(gds_rundown_ch);
	if (!reg->open)				/* Not open, no point to rundown */
	{
		if (reg->opening)		/* Died partway open, kill rest of way */
		{
			rel_crit(reg);
			mutex_cleanup(reg);
/* revist this to handle MM properly  SMW 98/12/16
                        if (NULL != csa->nl)
                        {
                                status = shmdt((caddr_t)csa->nl);
                                if (-1 == status)
                                        send_msg(VARLSTCNT(9) ERR_DBFILERR, 2, DB_LEN_STR(reg),
                                                ERR_TEXT, 2, LEN_AND_LIT("Error during shmdt"), errno);
                        }
*/
			shmdt((caddr_t)csa->nl);
			csa->nl = NULL;
		}
		REVERT;
		return;
	}
	switch(csd->acc_meth)
	{	/* Pass mm and bg through */
	    case dba_bg:
		is_mm = FALSE;
		break;
	    case dba_mm:
		is_mm = TRUE;
		break;
	    case dba_usr:
		assert(FALSE);
	    default:
		REVERT;
		return;
	}
	/* Cancel any pending flush timer for this region by this task */
	CANCEL_DB_TIMERS(reg, cancelled_timer, cancelled_dbsync_timer);
	we_are_last_user = FALSE;
	if (!csa->persistent_freeze)
		region_freeze(reg, FALSE, FALSE, FALSE);
	assert(!csa->read_lock);
	rel_crit(reg);		/* get locks to known state */
	mutex_cleanup(reg);
	/*
	 * We need to guarantee that none else access database file header when semid/shmid fields are reset.
	 * We already have created ftok semaphore in db_init or, mu_rndwn_file and did not remove it.
	 * So just lock it. We do it in blocking mode.
	 */
	if (!ftok_sem_lock(reg, FALSE, FALSE))
		rts_error(VARLSTCNT(4) ERR_DBFILERR, 2, DB_LEN_STR(reg));
	/*
	 * For mupip_jnl_recover we already have database access control semaphore.
	 * We do not release it. We release it from  mur_close_files.
	 */
	if (!mupip_jnl_recover)
	{
		sop[0].sem_num = 0; sop[0].sem_op = 0;	/* Wait for 0 */
		sop[1].sem_num = 0; sop[1].sem_op = 1;	/* Lock */
		sopcnt = 2;
		sop[0].sem_flg = sop[1].sem_flg = SEM_UNDO | IPC_NOWAIT; /* Don't wait the first time thru */
		SEMOP(udi->semid, sop, sopcnt, status);
		if (-1 == status)			/* We couldn't get it in one shot -- see if we already have it */
		{
			save_errno = errno;
			/* see comment about Linux specific difference in behaviour of semctl() with GETPID in gds_rundown_ch() */
			if (semctl(udi->semid, 0, GETPID) == process_id)
			{
				send_msg(VARLSTCNT(5) MAKE_MSG_INFO(ERR_CRITSEMFAIL), 2,
					DB_LEN_STR(reg),
					ERR_RNDWNSEMFAIL);
				REVERT;
				return;			/* Already in rundown for this region */
			}
			if (EAGAIN != save_errno)
			{
				assert(FALSE);
				rts_error(VARLSTCNT(9) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg),
					ERR_TEXT, 2, RTS_ERROR_TEXT("gds_rundown first semop/semctl"), save_errno);
			}
			sop[0].sem_flg = sop[1].sem_flg = SEM_UNDO;	/* Try again - blocking this time */
			SEMOP(udi->semid, sop, 2, status);
			if (-1 == status)			/* We couldn't get it at all.. */
				rts_error(VARLSTCNT(5) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg), errno);
		}
	}
	grabbed_access_sem = TRUE;
	/*
	 * We now have the dbinit/rundown lock, so we are alone in this code for this region
	 * and nobody else can attach.
	 * See if we are all alone in accessing this database shared memory.
	 */
	assert(csa->ref_cnt);	/* decrement private ref_cnt before shared ref_cnt decrement. */
	csa->ref_cnt--;		/* Currently journaling logic in gds_rundown() in VMS relies on this order to detect last writer */
	assert(!csa->ref_cnt);
	--csa->nl->ref_cnt;
	if (memcmp(csa->nl->now_running, gtm_release_name, gtm_release_name_len + 1))
	{	/* VERMISMATCH condition. Possible only if DSE */
		assert(dse_running);
		vermismatch = TRUE;
	} else
		vermismatch = FALSE;
	if (-1 == shmctl(udi->shmid, IPC_STAT, &shm_buf))
	{
		save_errno = errno;
		rts_error(VARLSTCNT(9) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg),
			ERR_TEXT, 2, RTS_ERROR_TEXT("gds_rundown shmctl"), save_errno);
	} else
		we_are_last_user =  (1 == shm_buf.shm_nattch) && !vermismatch;
	assert(!mupip_jnl_recover || we_are_last_user); /* recover => one user */
	if (-1 == (semval = semctl(udi->semid, 1, GETVAL)))
		rts_error(VARLSTCNT(5) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg), errno);
	we_are_last_writer = (1 == semval) && (FALSE == reg->read_only) && !vermismatch;/* There's one writer left and I am it */
	assert(!(mupip_jnl_recover && !reg->read_only) || we_are_last_writer); /* recover + R/W region => one writer */
	if (-1 == (ftok_semval = semctl(udi->ftok_semid, 1, GETVAL)))
		rts_error(VARLSTCNT(5) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg), errno);
	/* If csa->nl->donotflush_dbjnl is set, it means mupip recover/rollback was interrupted and therefore we should
	 * 	not flush shared memory contents to disk as they might be in an inconsistent state.
	 * In this case, we will go ahead and remove shared memory (without flushing the contents) in this routine.
	 * A reissue of the recover/rollback command will restore the database to a consistent state.
	 * Otherwise, if we have write access to this region, let us perform a few writing tasks.
	 */
	if (csa->nl->donotflush_dbjnl)
		csa->wbuf_dqd = 0;	/* ignore csa->wbuf_dqd status as we do not care about the cache contents */
	else if (!reg->read_only && !vermismatch)
	{	/* If we had an orphaned block and were interrupted, set wc_blocked so we can invoke wcs_recover */
		if (csa->wbuf_dqd)
		{
			grab_crit(reg);
			SET_TRACEABLE_VAR(csd->wc_blocked, TRUE);
			BG_TRACE_PRO_ANY(csa, wcb_gds_rundown);
                        send_msg(VARLSTCNT(8) ERR_WCBLOCKED, 6, LEN_AND_LIT("wcb_gds_rundown"),
                                process_id, &csa->ti->curr_tn, DB_LEN_STR(reg));
			csa->wbuf_dqd = 0;
			wcs_recover(reg);
			if (is_mm)
			{
				assert(FALSE);
				csd = csa->hdr;
			}
			BG_TRACE_PRO_ANY(csa, lost_block_recovery);
			rel_crit(reg);
		}
		if (JNL_ENABLED(csd) && (GTCM_GNP_SERVER_IMAGE == image_type))
			originator_prc_vec = NULL;
		/* If we are the last writing user, then everything must be flushed */
		if (we_are_last_writer)
		{	/* Time to flush out all of our buffers */
			if (is_mm)
			{
				if (csa->total_blks != csa->ti->total_blks)	/* do remap if file had been extended */
				{
					grab_crit(reg);
					wcs_mm_recover(reg);
					csd = csa->hdr;
					rel_crit(reg);
				}
				csa->nl->remove_shm = TRUE;
			}
			/* Note WCSFLU_SYNC_EPOCH ensures the epoch is synced to the journal and indirectly
			 * also ensures that the db is fsynced. We don't want to use it in the calls to
			 * wcs_flu() from t_end() and tp_tend() since we can defer it to out-of-crit there.
			 * In this case, since we are running down, we don't have any such option.
			 */
			csa->nl->remove_shm = wcs_flu(WCSFLU_FLUSH_HDR | WCSFLU_WRITE_EPOCH | WCSFLU_SYNC_EPOCH);
			/* Since we_are_last_writer, we should be guaranteed that wcs_flu() did not change csd, (in
			 * case of MM for potential file extension), even if it did a grab_crit().  Therefore, make
			 * sure that's true.
			 */
			assert(csd == csa->hdr);
			assert(0 == memcmp(csd->label, GDS_LABEL, GDS_LABEL_SZ - 1));
			csd->trans_hist.header_open_tn = csd->trans_hist.curr_tn;
		} else if ((cancelled_timer && (0 > csa->nl->wcs_timers)) || cancelled_dbsync_timer)
		{	/* cancelled pending db or jnl flush timers - flush database and journal buffers to disk */
			grab_crit(reg);
			/* we need to sync the epoch as the fact that there is no active pending flush timer implies
			 * there will be noone else who will flush the dirty buffers and EPOCH to disk in a timely fashion
			 */
			wcs_flu(WCSFLU_FLUSH_HDR | WCSFLU_WRITE_EPOCH | WCSFLU_SYNC_EPOCH);
			rel_crit(reg);
			assert((dba_mm == cs_data->acc_meth) || (csd == cs_data));
			csd = cs_data;	/* In case this is MM and wcs_flu() remapped an extended database, reset csd */
		}
		/* Do rundown journal processing after buffer flushes since they require jnl to be open */
		if (JNL_ENABLED(csd))
		{	/* the following tp_change_reg() is not needed due to the assert csa == cs_addrs at the beginning
			 * of gds_rundown(), but just to be safe. To be removed by 2002!! --- nars -- 2001/04/25.
			 */
			tp_change_reg();	/* call this because jnl_ensure_open checks cs_addrs rather than gv_cur_region */
			jpc = csa->jnl;
			jbp = jpc->jnl_buff;
			if (jbp->fsync_in_prog_latch.u.parts.latch_pid == process_id)
                        {
                                assert(FALSE);
                                COMPSWAP_UNLOCK(&jbp->fsync_in_prog_latch, process_id, 0, LOCK_AVAILABLE, 0);
                        }
                        if (jbp->io_in_prog_latch.u.parts.latch_pid == process_id)
                        {
                                assert(FALSE);
                                COMPSWAP_UNLOCK(&jbp->io_in_prog_latch, process_id, 0, LOCK_AVAILABLE, 0);
                        }
			if (((NOJNL != jpc->channel) && !JNL_FILE_SWITCHED(jpc))
				|| we_are_last_writer && (0 != csa->nl->jnl_file.u.inode))
			{	/* We need to close the journal file cleanly if we have the latest generation journal file open
				 *	or if we are the last writer and the journal file is open in shared memory (not necessarily
				 *	by ourselves e.g. the only process that opened the journal got shot abnormally)
				 * Note: we should not infer anything from the shared memory value of csa->nl->jnl_file.u.inode
				 * 	if we are not the last writer as it can be concurrently updated.
				 */
				grab_crit(reg);
				if (JNL_ENABLED(csd))
				{
					SET_GBL_JREC_TIME; /* jnl_ensure_open/jnl_put_jrt_pini/pfin/jnl_file_close all need it */
					/* Before writing to jnlfile, adjust jgbl.gbl_jrec_time if needed to maintain time order
					 * of jnl records. This needs to be done BEFORE the jnl_ensure_open as that could write
					 * journal records (if it decides to switch to a new journal file).
					 */
					ADJUST_GBL_JREC_TIME(jgbl, jbp);
					jnl_status = jnl_ensure_open();
					if (0 == jnl_status)
					{	/* If we_are_last_writer, we would have already done a wcs_flu() which would
						 * have written an epoch record and we are guaranteed no further updates
						 * since we are the last writer. So, just close the journal.
						 * Although we assert pini_addr should be non-zero for last_writer, we
						 * play it safe in PRO and write a PINI record if not written already.
						 */
						assert(!jbp->before_images || is_mm
								|| !we_are_last_writer || 0 != jpc->pini_addr);
						if (we_are_last_writer && 0 == jpc->pini_addr)
							jnl_put_jrt_pini(csa);
						if (0 != jpc->pini_addr)
							jnl_put_jrt_pfin(csa);
						/* If not the last writer and no pending flush timer left, do jnl flush now */
						if (!we_are_last_writer && (0 > csa->nl->wcs_timers))
						{
							if (SS_NORMAL == (jnl_status = jnl_flush(reg)))
							{
								assert(jbp->freeaddr == jbp->dskaddr);
								jnl_fsync(reg, jbp->dskaddr);
								assert(jbp->fsync_dskaddr == jbp->dskaddr);
							} else
							{
								send_msg(VARLSTCNT(9) ERR_JNLFLUSH, 2, JNL_LEN_STR(csd),
									ERR_TEXT, 2,
									RTS_ERROR_TEXT("Error with journal flush in gds_rundown"),
									jnl_status);
								assert(NOJNL == jpc->channel);/* jnl file lost has been triggered */
								/* In this routine, all code that follows from here on does not
								 * assume anything about the journaling characteristics of this
								 * database so it is safe to continue execution even though
								 * journaling got closed in the middle.
								 */
							}
						}
						jnl_file_close(reg, we_are_last_writer, FALSE);
					} else
						send_msg(VARLSTCNT(6) jnl_status, 4, JNL_LEN_STR(csd), DB_LEN_STR(reg));
				}
				rel_crit(reg);
			}
		}
		if (we_are_last_writer)			/* Flush the fileheader last and harden the file to disk */
		{
			grab_crit(reg);			/* To satisfy crit requirement in fileheader_sync() */
			memset(csd->machine_name, 0, MAX_MCNAMELEN); /* clear the machine_name field */
			if (!mupip_jnl_recover && we_are_last_user)
			{	/* mupip_jnl_recover will do this after mur_close_file */
				csd->semid = INVALID_SEMID;
				csd->shmid = INVALID_SHMID;
				csd->gt_sem_ctime.ctime = 0;
				csd->gt_shm_ctime.ctime = 0;
			}
			fileheader_sync(reg);
			rel_crit(reg);
			if (FALSE == is_mm)
			{
				if (-1 == fsync(udi->fd))		/* Sync it all */
				{
					rts_error(VARLSTCNT(9) ERR_DBFILERR, 2, DB_LEN_STR(reg),
						  ERR_TEXT, 2, RTS_ERROR_TEXT("Error during file sync at close"), errno);
				}
			} else
			{	/* Now do final MM file sync before exit */
#if !defined(TARGETED_MSYNC) && !defined(NO_MSYNC)
				if (-1 == fsync(udi->fd))		/* Sync it all */
				{
					rts_error(VARLSTCNT(9) ERR_DBFILERR, 2, DB_LEN_STR(reg),
						  ERR_TEXT, 2, RTS_ERROR_TEXT("Error during file sync at close"), errno);
				}
#else
				if (-1 == msync((caddr_t)csa->db_addrs[0], (size_t)(csa->db_addrs[1] - csa->db_addrs[0]), MS_SYNC))
				{
					rts_error(VARLSTCNT(9) ERR_DBFILERR, 2, DB_LEN_STR(reg),
						  ERR_TEXT, 2, RTS_ERROR_TEXT("Error during file msync at close"), errno);
				}
#endif
			}
                }
	} /* end if (!reg->read_only && !csa->nl->donotflush_dbjnl) */
	if (reg->read_only && we_are_last_user && !mupip_jnl_recover)
	{	/* mupip_jnl_recover will do this after mur_close_file */
		db_ipcs.semid = INVALID_SEMID;
		db_ipcs.shmid = INVALID_SHMID;
		db_ipcs.gt_sem_ctime = 0;
		db_ipcs.gt_shm_ctime = 0;
		db_ipcs.fn_len = reg->dyn.addr->fname_len;
		memcpy(db_ipcs.fn, reg->dyn.addr->fname, reg->dyn.addr->fname_len);
		db_ipcs.fn[reg->dyn.addr->fname_len] = 0;
 		/* request gtmsecshr to flush. read_only cannot flush itself */
		if (0 != send_mesg2gtmsecshr(FLUSH_DB_IPCS_INFO, 0, (char *)NULL, 0))
			rts_error(VARLSTCNT(8) ERR_DBFILERR, 2, DB_LEN_STR(reg),
				  ERR_TEXT, 2, RTS_ERROR_TEXT("gtmsecshr failed to update database file header"));
	}
	/* Done with file now, close it */
	if (-1 == close(udi->fd))
	{
		rts_error(VARLSTCNT(9) ERR_DBFILERR, 2, DB_LEN_STR(reg),
			  ERR_TEXT, 2, LEN_AND_LIT("Error during file close"), errno);
	}
	/* Unmap storage if mm mode but only the part that is not the fileheader (so shows up in dumps) */
	if (is_mm)
	{
		munmap_len = (sm_long_t)((csa->db_addrs[1] - csa->db_addrs[0]) - ROUND_UP(SIZEOF_FILE_HDR(csa->hdr),
											 MSYNC_ADDR_INCS));
		if (munmap_len > 0)
		{
			munmap((caddr_t)(csa->db_addrs[0] + ROUND_UP(SIZEOF_FILE_HDR(csa->hdr), MSYNC_ADDR_INCS)),
			       (size_t)(munmap_len));
#ifdef DEBUG_DB64
			rel_mmseg((caddr_t)csa->db_addrs[0]);
#endif
		}
	}
	/* Detach our shared memory while still under lock so reference counts will be
	 * correct for the next process to run down this region.
	 * In the process also get the remove_shm status from node_local before detaching.
	 * If csa->nl->donotflush_dbjnl is TRUE, it means we can safely remove shared memory without compromising data
	 * 	integrity as a reissue of recover will restore the database to a consistent state.
	 */
	remove_shm = !vermismatch && (csa->nl->remove_shm || csa->nl->donotflush_dbjnl);
	status = shmdt((caddr_t)csa->nl);
	csa->nl = NULL; /* dereferencing nl after detach is not right, so we set it to NULL so that we can test before dereference*/
	if (-1 == status)
		send_msg(VARLSTCNT(9) ERR_DBFILERR, 2, DB_LEN_STR(reg), ERR_TEXT, 2, LEN_AND_LIT("Error during shmdt"), errno);
	reg->open = FALSE;

	/* If file is still not in good shape, die here and now before we get rid of our storage */
	if (csa->wbuf_dqd)
		GTMASSERT;
	ipc_deleted = FALSE;
	/* If we are the very last user, remove shared storage id and the semaphores */
	if (we_are_last_user)
	{	/* remove shared storage, only if last writer to rundown did a successful wcs_flu() */
		assert(!vermismatch);
		if (remove_shm)
		{
			ipc_deleted = TRUE;
			if (0 != shm_rmid(udi->shmid))
				rts_error(VARLSTCNT(8) ERR_DBFILERR, 2, DB_LEN_STR(reg),
					ERR_TEXT, 2, RTS_ERROR_TEXT("Unable to remove shared memory"));
		} else if (is_src_server || is_updproc)
		{
			gtm_putmsg(VARLSTCNT(6) ERR_DBRNDWNWRN, 4, DB_LEN_STR(reg), process_id, process_id);
			send_msg(VARLSTCNT(6) ERR_DBRNDWNWRN, 4, DB_LEN_STR(reg), process_id, process_id);
		} else
			send_msg(VARLSTCNT(6) ERR_DBRNDWNWRN, 4, DB_LEN_STR(reg), process_id, process_id);
		/*
		 * Don't release semaphore in case of mupip recover/rollback; since it has standalone access.
		 * It will release the semaphore in mur_close_files.
		 */
		if (!mupip_jnl_recover)
		{
			if (0 != sem_rmid(udi->semid))
				rts_error(VARLSTCNT(8) ERR_DBFILERR, 2, DB_LEN_STR(reg),
					ERR_TEXT, 2, RTS_ERROR_TEXT("Unable to remove semaphore"));
			grabbed_access_sem = FALSE;
		}
	} else
	{
		assert(!mupip_jnl_recover);
		/* If we were writing, get rid of our writer access count semaphore */
		if (!reg->read_only)
			if (0 != (save_errno = do_semop(udi->semid, 1, -1, SEM_UNDO)))
				rts_error(VARLSTCNT(9) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg),
					ERR_TEXT, 2, RTS_ERROR_TEXT("gds_rundown write semaphore release"), save_errno);
		/* Now remove the rundown lock */
		if (0 != (save_errno = do_semop(udi->semid, 0, -1, SEM_UNDO)))
			rts_error(VARLSTCNT(9) ERR_CRITSEMFAIL, 2, DB_LEN_STR(reg),
				ERR_TEXT, 2, RTS_ERROR_TEXT("gds_rundown rundown semaphore release"), save_errno);
		grabbed_access_sem = FALSE;
	}
	if (!ftok_sem_release(reg, !mupip_jnl_recover, FALSE))
			rts_error(VARLSTCNT(4) ERR_DBFILERR, 2, DB_LEN_STR(reg));
	if (!ipc_deleted)
	{
		GET_CUR_TIME;
		if (is_src_server)
			gtm_putmsg(VARLSTCNT(8) ERR_IPCNOTDEL, 6, CTIME_BEFORE_NL, time_ptr,
				LEN_AND_LIT("Source server"), REG_LEN_STR(reg));
		if (is_updproc)
			gtm_putmsg(VARLSTCNT(8) ERR_IPCNOTDEL, 6, CTIME_BEFORE_NL, time_ptr,
				LEN_AND_LIT("Update process"), REG_LEN_STR(reg));
		if (mupip_jnl_recover)
		{
			gtm_putmsg(VARLSTCNT(8) ERR_IPCNOTDEL, 6, CTIME_BEFORE_NL, time_ptr,
				LEN_AND_LIT("Mupip journal process"), REG_LEN_STR(reg));
			send_msg(VARLSTCNT(8) ERR_IPCNOTDEL, 6, CTIME_BEFORE_NL, time_ptr,
				LEN_AND_LIT("Mupip journal process"), REG_LEN_STR(reg));
		}
	}
	REVERT;
}