MDEV-12699 preparation: Clean up recv_sys

The recv_sys data structures are accessed not only from the thread
that executes InnoDB plugin initialization, but also from the
InnoDB I/O threads, which can invoke recv_recover_page().

Assert that sufficient concurrency control is in place.
Some code was accessing recv_sys data structures without
holding recv_sys->mutex.

recv_recover_page(bpage): Refactor the call from buf_page_io_complete()
into a separate function that performs necessary steps. The
main thread was unnecessarily releasing and reacquiring recv_sys->mutex.

recv_recover_page(block,mtr,recv_addr): Pass more parameters from
the caller. Avoid redundant lookups and computations. Eliminate some
redundant variables.

recv_get_fil_addr_struct(): Assert that recv_sys->mutex is being held.
That was not always the case!

recv_scan_log_recs(): Acquire recv_sys->mutex for the whole duration
of the function. (While we are scanning and buffering redo log records,
no pages can be read in.)

recv_read_in_area(): Properly protect access with recv_sys->mutex.

recv_apply_hashed_log_recs(): Check recv_addr->state only once,
and continuously hold recv_sys->mutex. The mutex will be released
and reacquired inside recv_recover_page() and recv_read_in_area(),
allowing concurrent processing by buf_page_io_complete() in I/O threads.

extra/mariabackup/xtrabackup.cc

@@ -2752,8 +2752,13 @@ static bool xtrabackup_copy_logfile(bool last = false)
 			my_sleep(1000);
 		}
 
-		start_lsn = (lsn == start_lsn)
-			? 0 : xtrabackup_copy_log(start_lsn, lsn, last);
+		if (lsn == start_lsn) {
+			start_lsn = 0;
+		} else {
+			mutex_enter(&recv_sys->mutex);
+			start_lsn = xtrabackup_copy_log(start_lsn, lsn, last);
+			mutex_exit(&recv_sys->mutex);
+		}
 
 		log_mutex_exit();
 

storage/innobase/buf/buf0buf.cc

@@ -6057,9 +6057,7 @@ buf_page_io_complete(buf_page_t* bpage, bool dblwr, bool evict)
 				page_not_corrupt: bpage = bpage; );
 
 		if (recv_recovery_is_on()) {
-			/* Pages must be uncompressed for crash recovery. */
-			ut_a(uncompressed);
-			recv_recover_page(TRUE, (buf_block_t*) bpage);
+			recv_recover_page(bpage);
 		}
 
 		/* If space is being truncated then avoid ibuf operation.
@@ -6079,7 +6077,7 @@ buf_page_io_complete(buf_page_t* bpage, bool dblwr, bool evict)
 					<< " encrypted. However key "
 					"management plugin or used "
 					<< "key_version " << key_version
-					<< "is not found or"
+					<< " is not found or"
 					" used encryption algorithm or method does not match."
 					" Can't continue opening the table.";
 			} else {

storage/innobase/include/log0recv.h

@@ -49,12 +49,9 @@ dberr_t
 recv_find_max_checkpoint(ulint* max_field)
 	MY_ATTRIBUTE((nonnull, warn_unused_result));
 
-/** Apply the hashed log records to the page, if the page lsn is less than the
-lsn of a log record.
-@param just_read_in	whether the page recently arrived to the I/O handler
-@param block		the page in the buffer pool */
-void
-recv_recover_page(bool just_read_in, buf_block_t* block);
+/** Apply any buffered redo log to a page that was just read from a data file.
+@param[in,out]	bpage	buffer pool page */
+ATTRIBUTE_COLD void recv_recover_page(buf_page_t* bpage);
 
 /** Start recovering from a redo log checkpoint.
 @see recv_recovery_from_checkpoint_finish

storage/innobase/log/log0recv.cc

@@ -1766,6 +1766,8 @@ recv_get_fil_addr_struct(
 	ulint	space,	/*!< in: space id */
 	ulint	page_no)/*!< in: page number */
 {
+	ut_ad(mutex_own(&recv_sys->mutex));
+
 	recv_addr_t*	recv_addr;
 
 	for (recv_addr = static_cast<recv_addr_t*>(
@@ -1839,10 +1841,6 @@ recv_add_to_hash_table(
 		HASH_INSERT(recv_addr_t, addr_hash, recv_sys->addr_hash,
 			    recv_fold(space, page_no), recv_addr);
 		recv_sys->n_addrs++;
-#if 0
-		fprintf(stderr, "Inserting log rec for space %lu, page %lu\n",
-			space, page_no);
-#endif
 	}
 
 	UT_LIST_ADD_LAST(recv_addr->rec_list, recv);
@@ -1911,151 +1909,71 @@ recv_data_copy_to_buf(
 
 /** Apply the hashed log records to the page, if the page lsn is less than the
 lsn of a log record.
-@param just_read_in	whether the page recently arrived to the I/O handler
-@param block		the page in the buffer pool */
-void
-recv_recover_page(bool just_read_in, buf_block_t* block)
+@param[in,out]	block		buffer pool page
+@param[in,out]	mtr		mini-transaction
+@param[in,out]	recv_addr	recovery address */
+static void recv_recover_page(buf_block_t* block, mtr_t& mtr,
+			      recv_addr_t* recv_addr)
 {
 	page_t*		page;
 	page_zip_des_t*	page_zip;
-	recv_addr_t*	recv_addr;
-	recv_t*		recv;
-	byte*		buf;
-	lsn_t		start_lsn;
-	lsn_t		end_lsn;
-	lsn_t		page_lsn;
-	lsn_t		page_newest_lsn;
-	ibool		modification_to_page;
-	mtr_t		mtr;
-
-	mutex_enter(&(recv_sys->mutex));
-
-	if (recv_sys->apply_log_recs == FALSE) {
-
-		/* Log records should not be applied now */
-
-		mutex_exit(&(recv_sys->mutex));
-
-		return;
-	}
-
-	recv_addr = recv_get_fil_addr_struct(block->page.id.space(),
-					     block->page.id.page_no());
-
-	if ((recv_addr == NULL)
-	    || (recv_addr->state == RECV_BEING_PROCESSED)
-	    || (recv_addr->state == RECV_PROCESSED)) {
-		ut_ad(recv_addr == NULL || recv_needed_recovery);
-
-		mutex_exit(&(recv_sys->mutex));
-
-		return;
-	}
 
+	ut_ad(mutex_own(&recv_sys->mutex));
+	ut_ad(recv_sys->apply_log_recs);
 	ut_ad(recv_needed_recovery);
+	ut_ad(recv_addr->state != RECV_BEING_PROCESSED);
+	ut_ad(recv_addr->state != RECV_PROCESSED);
 
 	if (UNIV_UNLIKELY(srv_print_verbose_log == 2)) {
 		fprintf(stderr, "Applying log to page %u:%u\n",
 			recv_addr->space, recv_addr->page_no);
 	}
 
-	DBUG_PRINT("ib_log",
-		   ("Applying log to page %u:%u",
-		    recv_addr->space, recv_addr->page_no));
+	DBUG_LOG("ib_log", "Applying log to page " << block->page.id);
 
 	recv_addr->state = RECV_BEING_PROCESSED;
-
-	mutex_exit(&(recv_sys->mutex));
-
-	mtr_start(&mtr);
-	mtr_set_log_mode(&mtr, MTR_LOG_NONE);
+	mutex_exit(&recv_sys->mutex);
 
 	page = block->frame;
 	page_zip = buf_block_get_page_zip(block);
 
-	if (just_read_in) {
-		/* Move the ownership of the x-latch on the page to
-		this OS thread, so that we can acquire a second
-		x-latch on it.  This is needed for the operations to
-		the page to pass the debug checks. */
-
-		rw_lock_x_lock_move_ownership(&block->lock);
-	}
-
-	ibool	success = buf_page_get_known_nowait(
-		RW_X_LATCH, block, BUF_KEEP_OLD,
-		__FILE__, __LINE__, &mtr);
-	ut_a(success);
-
-	buf_block_dbg_add_level(block, SYNC_NO_ORDER_CHECK);
-
-	/* Read the newest modification lsn from the page */
+	/* The page may have been modified in the buffer pool.
+	FIL_PAGE_LSN would only be updated right before flushing. */
+	lsn_t page_lsn = buf_page_get_newest_modification(&block->page);
+	if (!page_lsn) {
 		page_lsn = mach_read_from_8(page + FIL_PAGE_LSN);
-
-	/* It may be that the page has been modified in the buffer
-	pool: read the newest modification lsn there */
-
-	page_newest_lsn = buf_page_get_newest_modification(&block->page);
-
-	if (page_newest_lsn) {
-
-		page_lsn = page_newest_lsn;
 	}
 
-	modification_to_page = FALSE;
-	start_lsn = end_lsn = 0;
+	lsn_t start_lsn = 0, end_lsn = 0;
 
-	recv = UT_LIST_GET_FIRST(recv_addr->rec_list);
+	if (srv_is_tablespace_truncated(recv_addr->space)) {
+		/* The table will be truncated after applying
+		normal redo log records. */
+		goto skip_log;
+	}
 
-	while (recv) {
+	for (recv_t* recv = UT_LIST_GET_FIRST(recv_addr->rec_list);
+	     recv; recv = UT_LIST_GET_NEXT(rec_list, recv)) {
+		ut_ad(recv->start_lsn);
 		end_lsn = recv->end_lsn;
-
 		ut_ad(end_lsn <= log_sys->log.scanned_lsn);
 
-		if (recv->len > RECV_DATA_BLOCK_SIZE) {
-			/* We have to copy the record body to a separate
-			buffer */
-
-			buf = static_cast<byte*>(ut_malloc_nokey(recv->len));
-
-			recv_data_copy_to_buf(buf, recv);
+		if (recv->start_lsn < page_lsn) {
+			/* Ignore this record, because there are later changes
+			for this page. */
+		} else if (srv_was_tablespace_truncated(
+				   fil_space_get(recv_addr->space))
+			   && recv->start_lsn
+			   < truncate_t::get_truncated_tablespace_init_lsn(
+				   recv_addr->space)) {
+			/* If per-table tablespace was truncated and
+			there exist REDO records before truncate that
+			are to be applied as part of recovery
+			(checkpoint didn't happen since truncate was
+			done) skip such records using lsn check as
+			they may not stand valid post truncate. */
 		} else {
-			buf = ((byte*)(recv->data)) + sizeof(recv_data_t);
-		}
-
-		/* If per-table tablespace was truncated and there exist REDO
-		records before truncate that are to be applied as part of
-		recovery (checkpoint didn't happen since truncate was done)
-		skip such records using lsn check as they may not stand valid
-		post truncate.
-		LSN at start of truncate is recorded and any redo record
-		with LSN less than recorded LSN is skipped.
-		Note: We can't skip complete recv_addr as same page may have
-		valid REDO records post truncate those needs to be applied. */
-		bool	skip_recv = false;
-		if (srv_was_tablespace_truncated(fil_space_get(recv_addr->space))) {
-			lsn_t	init_lsn =
-				truncate_t::get_truncated_tablespace_init_lsn(
-				recv_addr->space);
-			skip_recv = (recv->start_lsn < init_lsn);
-		}
-
-		/* Ignore applying the redo logs for tablespace that is
-		truncated. Post recovery there is fixup action that will
-		restore the tablespace back to normal state.
-		Applying redo at this stage can result in error given that
-		redo will have action recorded on page before tablespace
-		was re-inited and that would lead to an error while applying
-		such action. */
-		if (recv->start_lsn >= page_lsn
-		    && !srv_is_tablespace_truncated(recv_addr->space)
-		    && !skip_recv) {
-
-			lsn_t	end_lsn;
-
-			if (!modification_to_page) {
-
-				modification_to_page = TRUE;
+			if (!start_lsn) {
 				start_lsn = recv->start_lsn;
 			}
 
@@ -2066,50 +1984,54 @@ recv_recover_page(bool just_read_in, buf_block_t* block)
 					recv_addr->space, recv_addr->page_no);
 			}
 
-			DBUG_PRINT("ib_log",
-				   ("apply " LSN_PF ":"
-				    " %s len " ULINTPF " page %u:%u",
-				    recv->start_lsn,
-				    get_mlog_string(recv->type), recv->len,
-				    recv_addr->space,
-				    recv_addr->page_no));
+			DBUG_LOG("ib_log", "apply " << recv->start_lsn << ": "
+				 << get_mlog_string(recv->type)
+				 << " len " << recv->len
+				 << " page " << block->page.id);
+
+			byte* buf;
+
+			if (recv->len > RECV_DATA_BLOCK_SIZE) {
+				/* We have to copy the record body to
+				a separate buffer */
+				buf = static_cast<byte*>
+					(ut_malloc_nokey(recv->len));
+				recv_data_copy_to_buf(buf, recv);
+			} else {
+				buf = reinterpret_cast<byte*>(recv->data)
+					+ sizeof *recv->data;
+			}
 
 			recv_parse_or_apply_log_rec_body(
 				recv->type, buf, buf + recv->len,
-				recv_addr->space, recv_addr->page_no,
-				true, block, &mtr);
+				block->page.id.space(),
+				block->page.id.page_no(), true, block, &mtr);
 
 			end_lsn = recv->start_lsn + recv->len;
 			mach_write_to_8(FIL_PAGE_LSN + page, end_lsn);
-			mach_write_to_8(UNIV_PAGE_SIZE
+			mach_write_to_8(srv_page_size
 					- FIL_PAGE_END_LSN_OLD_CHKSUM
 					+ page, end_lsn);
 
 			if (page_zip) {
-				mach_write_to_8(FIL_PAGE_LSN
-						+ page_zip->data, end_lsn);
-			}
+				mach_write_to_8(FIL_PAGE_LSN + page_zip->data,
+						end_lsn);
 			}
 
 			if (recv->len > RECV_DATA_BLOCK_SIZE) {
 				ut_free(buf);
 			}
-
-		recv = UT_LIST_GET_NEXT(rec_list, recv);
+		}
 	}
 
+skip_log:
 #ifdef UNIV_ZIP_DEBUG
-	if (fil_page_index_page_check(page)) {
-		page_zip_des_t*	page_zip = buf_block_get_page_zip(block);
-
-		ut_a(!page_zip
+	ut_ad(!fil_page_index_page_check(page)
+	      || !page_zip
 	      || page_zip_validate_low(page_zip, page, NULL, FALSE));
-	}
 #endif /* UNIV_ZIP_DEBUG */
 
-	if (modification_to_page) {
-		ut_a(block);
-
+	if (start_lsn) {
 		log_flush_order_mutex_enter();
 		buf_flush_recv_note_modification(block, start_lsn, end_lsn);
 		log_flush_order_mutex_exit();
@@ -2119,8 +2041,7 @@ recv_recover_page(bool just_read_in, buf_block_t* block)
 	lsn values of page */
 
 	mtr.discard_modifications();
-
-	mtr_commit(&mtr);
+	mtr.commit();
 
 	ib_time_t time = ut_time();
 
@@ -2130,6 +2051,7 @@ recv_recover_page(bool just_read_in, buf_block_t* block)
 		recv_max_page_lsn = page_lsn;
 	}
 
+	ut_ad(recv_addr->state == RECV_BEING_PROCESSED);
 	recv_addr->state = RECV_PROCESSED;
 
 	ut_a(recv_sys->n_addrs > 0);
@@ -2140,52 +2062,76 @@ recv_recover_page(bool just_read_in, buf_block_t* block)
 				INNODB_EXTEND_TIMEOUT_INTERVAL, "To recover: " ULINTPF " pages from log", n);
 		}
 	}
+}
+
+/** Apply any buffered redo log to a page that was just read from a data file.
+@param[in,out]	bpage	buffer pool page */
+void recv_recover_page(buf_page_t* bpage)
+{
+	mtr_t mtr;
+	mtr.start();
+	mtr.set_log_mode(MTR_LOG_NONE);
+
+	ut_ad(buf_page_get_state(bpage) == BUF_BLOCK_FILE_PAGE);
+	buf_block_t* block = reinterpret_cast<buf_block_t*>(bpage);
 
+	/* Move the ownership of the x-latch on the page to
+	this OS thread, so that we can acquire a second
+	x-latch on it.  This is needed for the operations to
+	the page to pass the debug checks. */
+	rw_lock_x_lock_move_ownership(&block->lock);
+	buf_block_dbg_add_level(block, SYNC_NO_ORDER_CHECK);
+	ibool	success = buf_page_get_known_nowait(
+		RW_X_LATCH, block, BUF_KEEP_OLD,
+		__FILE__, __LINE__, &mtr);
+	ut_a(success);
+
+	mutex_enter(&recv_sys->mutex);
+	if (!recv_sys->apply_log_recs) {
+	} else if (recv_addr_t* recv_addr = recv_get_fil_addr_struct(
+			   bpage->id.space(), bpage->id.page_no())) {
+		switch (recv_addr->state) {
+		case RECV_BEING_PROCESSED:
+		case RECV_PROCESSED:
+			break;
+		default:
+			recv_recover_page(block, mtr, recv_addr);
+			goto func_exit;
+		}
+	}
+
+	mtr.commit();
+func_exit:
 	mutex_exit(&recv_sys->mutex);
+	ut_ad(mtr.has_committed());
 }
 
 /** Reads in pages which have hashed log records, from an area around a given
 page number.
-@param[in]	page_id	page id
-@return number of pages found */
-static ulint recv_read_in_area(const page_id_t page_id)
+@param[in]	page_id	page id */
+static void recv_read_in_area(const page_id_t page_id)
 {
-	recv_addr_t* recv_addr;
 	ulint	page_nos[RECV_READ_AHEAD_AREA];
-	ulint	low_limit;
-	ulint	n;
-
-	low_limit = page_id.page_no()
+	ulint	page_no = page_id.page_no()
 		- (page_id.page_no() % RECV_READ_AHEAD_AREA);
-
-	n = 0;
-
-	for (ulint page_no = low_limit;
-	     page_no < low_limit + RECV_READ_AHEAD_AREA;
-	     page_no++) {
-
-		recv_addr = recv_get_fil_addr_struct(page_id.space(), page_no);
-
-		const page_id_t	cur_page_id(page_id.space(), page_no);
-
-		if (recv_addr && !buf_page_peek(cur_page_id)) {
-
-			mutex_enter(&(recv_sys->mutex));
-
-			if (recv_addr->state == RECV_NOT_PROCESSED) {
+	ulint*	p = page_nos;
+
+	for (const ulint up_limit = page_no + RECV_READ_AHEAD_AREA;
+	     page_no < up_limit; page_no++) {
+		recv_addr_t* recv_addr = recv_get_fil_addr_struct(
+			page_id.space(), page_no);
+		if (recv_addr
+		    && recv_addr->state == RECV_NOT_PROCESSED
+		    && !buf_page_peek(page_id_t(page_id.space(), page_no))) {
 			recv_addr->state = RECV_BEING_READ;
-
-				page_nos[n] = page_no;
-
-				n++;
-			}
-
-			mutex_exit(&(recv_sys->mutex));
+			*p++ = page_no;
 		}
 	}
 
-	buf_read_recv_pages(FALSE, page_id.space(), page_nos, n);
-	return(n);
+	mutex_exit(&recv_sys->mutex);
+	buf_read_recv_pages(FALSE, page_id.space(), page_nos,
+			    ulint(p - page_nos));
+	mutex_enter(&recv_sys->mutex);
 }
 
 /** Apply the hash table of stored log records to persistent data pages.
@@ -2238,49 +2184,55 @@ void recv_apply_hashed_log_recs(bool last_batch)
 		}
 	}
 
+	mtr_t mtr;
+
 	for (ulint i = 0; i < hash_get_n_cells(recv_sys->addr_hash); i++) {
 		for (recv_addr_t* recv_addr = static_cast<recv_addr_t*>(
 			     HASH_GET_FIRST(recv_sys->addr_hash, i));
 		     recv_addr;
 		     recv_addr = static_cast<recv_addr_t*>(
 				HASH_GET_NEXT(addr_hash, recv_addr))) {
-
-			if (srv_is_tablespace_truncated(recv_addr->space)) {
-				/* Avoid applying REDO log for the tablespace
-				that is schedule for TRUNCATE. */
+			if (!UT_LIST_GET_LEN(recv_addr->rec_list)) {
+ignore:
 				ut_a(recv_sys->n_addrs);
-				recv_addr->state = RECV_DISCARDED;
 				recv_sys->n_addrs--;
 				continue;
 			}
 
-			if (recv_addr->state == RECV_DISCARDED
-			    || !UT_LIST_GET_LEN(recv_addr->rec_list)) {
-				ut_a(recv_sys->n_addrs);
-				recv_sys->n_addrs--;
+			switch (recv_addr->state) {
+			case RECV_BEING_READ:
+			case RECV_BEING_PROCESSED:
+			case RECV_PROCESSED:
 				continue;
+			case RECV_DISCARDED:
+				goto ignore;
+			case RECV_NOT_PROCESSED:
+				break;
+			}
+
+			if (srv_is_tablespace_truncated(recv_addr->space)) {
+				/* Avoid applying REDO log for the tablespace
+				that is schedule for TRUNCATE. */
+				recv_addr->state = RECV_DISCARDED;
+				goto ignore;
 			}
 
 			const page_id_t page_id(recv_addr->space,
 						recv_addr->page_no);
 
-			if (recv_addr->state == RECV_NOT_PROCESSED) {
-				mutex_exit(&recv_sys->mutex);
-				mtr_t mtr;
 			mtr.start();
+			mtr.set_log_mode(MTR_LOG_NONE);
 			if (buf_block_t* block = buf_page_get_gen(
-					    page_id, univ_page_size,
-					    RW_X_LATCH, NULL,
-					    BUF_GET_IF_IN_POOL,
+				    page_id, univ_page_size, RW_X_LATCH,
+				    NULL, BUF_GET_IF_IN_POOL,
 				    __FILE__, __LINE__, &mtr, NULL)) {
 				buf_block_dbg_add_level(
 					block, SYNC_NO_ORDER_CHECK);
-					recv_recover_page(FALSE, block);
+				recv_recover_page(block, mtr, recv_addr);
+				ut_ad(mtr.has_committed());
 			} else {
-					recv_read_in_area(page_id);
-				}
 				mtr.commit();
-				mutex_enter(&recv_sys->mutex);
+				recv_read_in_area(page_id);
 			}
 		}
 	}
@@ -2557,6 +2509,7 @@ bool recv_parse_log_recs(lsn_t checkpoint_lsn, store_t store, bool apply)
 	byte*		body;
 
 	ut_ad(log_mutex_own());
+	ut_ad(mutex_own(&recv_sys->mutex));
 	ut_ad(recv_sys->parse_start_lsn != 0);
 loop:
 	ptr = recv_sys->buf + recv_sys->recovered_offset;
@@ -3125,6 +3078,8 @@ recv_scan_log_recs(
 
 	*group_scanned_lsn = scanned_lsn;
 
+	mutex_enter(&recv_sys->mutex);
+
 	if (more_data && !recv_sys->found_corrupt_log) {
 		/* Try to parse more log records */
 
@@ -3134,7 +3089,8 @@ recv_scan_log_recs(
 			      || recv_sys->found_corrupt_fs
 			      || recv_sys->mlog_checkpoint_lsn
 			      == recv_sys->recovered_lsn);
-			return(true);
+			finished = true;
+			goto func_exit;
 		}
 
 		if (*store_to_hash != STORE_NO
@@ -3155,6 +3111,8 @@ recv_scan_log_recs(
 		}
 	}
 
+func_exit:
+	mutex_exit(&recv_sys->mutex);
 	return(finished);
 }