Many files:

  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
  Track crash in buf_LRU_block_remove_hashed_page + 1807 reported in MySQL-3.23.5x


sql/ha_innodb.cc:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
sql/sql_class.cc:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
sql/sql_parse.cc:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
sql/sql_table.cc:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
sql/ha_innodb.h:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
sql/handler.h:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
sql/lex.h:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
sql/mysql_priv.h:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
sql/sql_class.h:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
sql/sql_lex.h:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
sql/sql_yacc.yy:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
innobase/ha/ha0ha.c:
  Track crash in buf_LRU_block_remove_hashed_page + 1807 reported in MySQL-3.23.5x
innobase/ha/hash0hash.c:
  Track crash in buf_LRU_block_remove_hashed_page + 1807 reported in MySQL-3.23.5x
innobase/buf/buf0buf.c:
  Track crash in buf_LRU_block_remove_hashed_page + 1807 reported in MySQL-3.23.5x
innobase/buf/buf0flu.c:
  Track crash in buf_LRU_block_remove_hashed_page + 1807 reported in MySQL-3.23.5x
innobase/buf/buf0lru.c:
  Track crash in buf_LRU_block_remove_hashed_page + 1807 reported in MySQL-3.23.5x
innobase/buf/buf0rea.c:
  Track crash in buf_LRU_block_remove_hashed_page + 1807 reported in MySQL-3.23.5x
innobase/btr/btr0btr.c:
  Track crash in buf_LRU_block_remove_hashed_page + 1807 reported in MySQL-3.23.5x
innobase/btr/btr0sea.c:
  Track crash in buf_LRU_block_remove_hashed_page + 1807 reported in MySQL-3.23.5x
innobase/fil/fil0fil.c:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
innobase/include/buf0buf.h:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
innobase/include/ha0ha.h:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
innobase/include/hash0hash.h:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
innobase/include/row0mysql.h:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
innobase/include/buf0buf.ic:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
innobase/include/ha0ha.ic:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
innobase/include/ibuf0ibuf.ic:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
innobase/page/page0page.c:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
innobase/row/row0mysql.c:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
innobase/row/row0purge.c:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
innobase/row/row0uins.c:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE
innobase/row/row0umod.c:
  ALTER TABLE ... DISCARD/IMPORT TABLESPACE

4 files changed, 108 insertions, 36 deletions

diff --git a/innobase/buf/buf0buf.c b/innobase/buf/buf0buf.c
index 1e1c6b25c1d..b403cc4df0d 100644
--- a/innobase/buf/buf0buf.c
+++ b/innobase/buf/buf0buf.c
@@ -468,6 +468,11 @@ buf_block_init(
 
 	block->check_index_page_at_flush = FALSE;
 
+	block->in_free_list = FALSE;
+	block->in_LRU_list = FALSE;
+
+	block->n_pointers = 0;
+
 	rw_lock_create(&(block->lock));
 	ut_ad(rw_lock_validate(&(block->lock)));
 	
@@ -687,6 +692,7 @@ buf_pool_init(
 		}
 
 		UT_LIST_ADD_LAST(free, buf_pool->free, block);
+		block->in_free_list = TRUE;
 	}
 
 	mutex_exit(&(buf_pool->mutex));
@@ -830,7 +836,7 @@ buf_page_make_young(
 
 	block = buf_block_align(frame);
 
-	ut_ad(block->state == BUF_BLOCK_FILE_PAGE);
+	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
 
 	buf_LRU_make_block_young(block);
 
@@ -845,7 +851,7 @@ buf_block_free(
 /*===========*/
 	buf_block_t*	block)	/* in, own: block to be freed */
 {
-	ut_ad(block->state != BUF_BLOCK_FILE_PAGE);
+	ut_a(block->state != BUF_BLOCK_FILE_PAGE);
 
 	mutex_enter(&(buf_pool->mutex));
 
@@ -1109,6 +1115,8 @@ loop:
 		goto loop;
 	}
 
+	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
+
 	must_read = FALSE;
 	
 	if (block->io_fix == BUF_IO_READ) {
@@ -1407,6 +1415,8 @@ buf_page_get_known_nowait(
 		return(FALSE);
 	}
 
+	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
+
 #ifdef UNIV_SYNC_DEBUG
 	buf_block_buf_fix_inc_debug(block, file, line);
 #else
@@ -1517,7 +1527,7 @@ buf_page_init(
 	buf_block_t*	block)	/* in: block to init */
 {
 	ut_ad(mutex_own(&(buf_pool->mutex)));
-	ut_ad(block->state == BUF_BLOCK_READY_FOR_USE);
+	ut_a(block->state != BUF_BLOCK_FILE_PAGE);
 
 	/* Set the state of the block */
 	block->magic_n		= BUF_BLOCK_MAGIC_N;
@@ -1533,6 +1543,18 @@ buf_page_init(
 	
 	/* Insert into the hash table of file pages */
 
+        if (buf_page_hash_get(space, offset)) {
+                fprintf(stderr,
+"InnoDB: Error: page %lu %lu already found from the hash table\n", space,
+							offset);
+                buf_print();
+                buf_LRU_print();
+                buf_validate();
+                buf_LRU_validate();
+
+                ut_a(0);
+        }
+
 	HASH_INSERT(buf_block_t, hash, buf_pool->page_hash,
 				buf_page_address_fold(space, offset), block);
 
@@ -1605,7 +1627,7 @@ buf_page_init_for_read(
 	
 	block = buf_block_alloc();
 
-	ut_ad(block);
+	ut_a(block);
 
 	mutex_enter(&(buf_pool->mutex));
 
@@ -1769,6 +1791,8 @@ buf_page_io_complete(
 	
 	ut_ad(block);
 
+	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
+
 	io_type = block->io_fix;
 
 	if (io_type == BUF_IO_READ) {
diff --git a/innobase/buf/buf0flu.c b/innobase/buf/buf0flu.c
index 3f8022f36bc..27a1829942d 100644
--- a/innobase/buf/buf0flu.c
+++ b/innobase/buf/buf0flu.c
@@ -50,6 +50,8 @@ buf_flush_insert_into_flush_list(
 {
 	ut_ad(mutex_own(&(buf_pool->mutex)));
 
+	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
+
 	ut_ad((UT_LIST_GET_FIRST(buf_pool->flush_list) == NULL)
 	      || (ut_dulint_cmp(
 			(UT_LIST_GET_FIRST(buf_pool->flush_list))
@@ -131,7 +133,7 @@ buf_flush_ready_for_flush(
 	ulint		flush_type)/* in: BUF_FLUSH_LRU or BUF_FLUSH_LIST */
 {
 	ut_ad(mutex_own(&(buf_pool->mutex)));
-	ut_ad(block->state == BUF_BLOCK_FILE_PAGE);
+	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
 
 	if ((ut_dulint_cmp(block->oldest_modification, ut_dulint_zero) > 0)
 	    					&& (block->io_fix == 0)) {
@@ -163,6 +165,8 @@ buf_flush_write_complete(
 	ut_ad(block);
 	ut_ad(mutex_own(&(buf_pool->mutex)));
 
+	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
+
 	block->oldest_modification = ut_dulint_zero;
 
 	UT_LIST_REMOVE(flush_list, buf_pool->flush_list, block);
@@ -282,6 +286,8 @@ buf_flush_buffered_writes(void)
 	for (i = 0; i < trx_doublewrite->first_free; i++) {
 		block = trx_doublewrite->buf_block_arr[i];
 
+		ut_a(block->state == BUF_BLOCK_FILE_PAGE);
+
 		fil_io(OS_FILE_WRITE | OS_AIO_SIMULATED_WAKE_LATER,
 			FALSE, block->space, block->offset, 0, UNIV_PAGE_SIZE,
 		 			(void*)block->frame, (void*)block);
@@ -321,6 +327,8 @@ buf_flush_post_to_doublewrite_buf(
 try_again:
 	mutex_enter(&(trx_doublewrite->mutex));
 
+	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
+
 	if (trx_doublewrite->first_free
 				>= 2 * TRX_SYS_DOUBLEWRITE_BLOCK_SIZE) {
 		mutex_exit(&(trx_doublewrite->mutex));
@@ -395,6 +403,8 @@ buf_flush_write_block_low(
 /*======================*/
 	buf_block_t*	block)	/* in: buffer block to write */
 {
+	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
+
 #ifdef UNIV_IBUF_DEBUG
 	ut_a(ibuf_count_get(block->space, block->offset) == 0);
 #endif
@@ -443,7 +453,7 @@ buf_flush_try_page(
 
 	block = buf_page_hash_get(space, offset);
 
-	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
+	ut_a(!block || block->state == BUF_BLOCK_FILE_PAGE);
 
 	if (flush_type == BUF_FLUSH_LIST
 	    && block && buf_flush_ready_for_flush(block, flush_type)) {
@@ -635,6 +645,7 @@ buf_flush_try_neighbors(
 	for (i = low; i < high; i++) {
 
 		block = buf_page_hash_get(space, i);
+		ut_a(!block || block->state == BUF_BLOCK_FILE_PAGE);
 
 		if (block && flush_type == BUF_FLUSH_LRU && i != offset
 		    && !block->old) {
@@ -703,10 +714,10 @@ buf_flush_batch(
 	ulint		offset;
 	ibool		found;
 	
-	ut_ad((flush_type == BUF_FLUSH_LRU) || (flush_type == BUF_FLUSH_LIST)); 
-	ut_ad((flush_type != BUF_FLUSH_LIST) ||
-					sync_thread_levels_empty_gen(TRUE));
-
+	ut_ad((flush_type == BUF_FLUSH_LRU)
+					|| (flush_type == BUF_FLUSH_LIST)); 
+	ut_ad((flush_type != BUF_FLUSH_LIST)
+					|| sync_thread_levels_empty_gen(TRUE));
 	mutex_enter(&(buf_pool->mutex));
 
 	if ((buf_pool->n_flush[flush_type] > 0)
@@ -737,7 +748,6 @@ buf_flush_batch(
 			ut_ad(flush_type == BUF_FLUSH_LIST);
 
 			block = UT_LIST_GET_LAST(buf_pool->flush_list);
-
 			if (!block
 			    || (ut_dulint_cmp(block->oldest_modification,
 			    				lsn_limit) >= 0)) {
@@ -756,6 +766,7 @@ buf_flush_batch(
 		function a pointer to a block in the list! */
 
 	    	while ((block != NULL) && !found) {
+			ut_a(block->state == BUF_BLOCK_FILE_PAGE);
 
 			if (buf_flush_ready_for_flush(block, flush_type)) {
 
@@ -781,7 +792,6 @@ buf_flush_batch(
 			} else if (flush_type == BUF_FLUSH_LRU) {
 
 				block = UT_LIST_GET_PREV(LRU, block);
-
 			} else {
 				ut_ad(flush_type == BUF_FLUSH_LIST);
 
diff --git a/innobase/buf/buf0lru.c b/innobase/buf/buf0lru.c
index 5d48d460745..55a5ecbeba5 100644
--- a/innobase/buf/buf0lru.c
+++ b/innobase/buf/buf0lru.c
@@ -82,6 +82,8 @@ scan_again:
 	block = UT_LIST_GET_LAST(buf_pool->LRU);
 
 	while (block != NULL) {
+	        ut_a(block->state == BUF_BLOCK_FILE_PAGE);
+
 		if (block->space == id
 		    && (block->buf_fix_count > 0 || block->io_fix != 0)) {
 
@@ -199,19 +201,16 @@ buf_LRU_search_and_free_block(
 	mutex_enter(&(buf_pool->mutex));
 	
 	freed = FALSE;
-	
 	block = UT_LIST_GET_LAST(buf_pool->LRU);
 
 	while (block != NULL) {
-
+	        ut_a(block->in_LRU_list);
 		if (buf_flush_ready_for_replace(block)) {
-
 			if (buf_debug_prints) {
 				printf(
 				"Putting space %lu page %lu to free list\n",
 					block->space, block->offset);
 			}
-			
 			buf_LRU_block_remove_hashed_page(block);
 
 			mutex_exit(&(buf_pool->mutex));
@@ -223,25 +222,21 @@ buf_LRU_search_and_free_block(
 			if (block->frame) {
 				btr_search_drop_page_hash_index(block->frame);
 			}
-
 			mutex_enter(&(buf_pool->mutex));
 
 			ut_a(block->buf_fix_count == 0);
 
 			buf_LRU_block_free_hashed_page(block);
-
 			freed = TRUE;
 
 			break;
 		}
-
 		block = UT_LIST_GET_PREV(LRU, block);
 		distance++;
 
 		if (!freed && n_iterations <= 10
 		    && distance > 100 + (n_iterations * buf_pool->curr_size)
 					/ 10) {
-
 			buf_pool->LRU_flush_ended = 0;
 
 			mutex_exit(&(buf_pool->mutex));
@@ -249,15 +244,12 @@ buf_LRU_search_and_free_block(
 			return(FALSE);
 		}
 	}
-
 	if (buf_pool->LRU_flush_ended > 0) {
 		buf_pool->LRU_flush_ended--;
 	}
- 
-	if (!freed) {
+ 	if (!freed) {
 		buf_pool->LRU_flush_ended = 0;
 	}
-
 	mutex_exit(&(buf_pool->mutex));
 	
 	return(freed);
@@ -355,7 +347,11 @@ loop:
 	if (UT_LIST_GET_LEN(buf_pool->free) > 0) {
 		
 		block = UT_LIST_GET_FIRST(buf_pool->free);
+		ut_a(block->in_free_list);
 		UT_LIST_REMOVE(free, buf_pool->free, block);
+		block->in_free_list = FALSE;
+		ut_a(block->state != BUF_BLOCK_FILE_PAGE);
+	        ut_a(!block->in_LRU_list);
 
 		if (srv_use_awe) {
 			if (block->frame) {
@@ -466,7 +462,7 @@ buf_LRU_old_adjust_len(void)
 	ulint	old_len;
 	ulint	new_len;
 
-	ut_ad(buf_pool->LRU_old);
+	ut_a(buf_pool->LRU_old);
 	ut_ad(mutex_own(&(buf_pool->mutex)));
 	ut_ad(3 * (BUF_LRU_OLD_MIN_LEN / 8) > BUF_LRU_OLD_TOLERANCE + 5);
 
@@ -474,6 +470,8 @@ buf_LRU_old_adjust_len(void)
 		old_len = buf_pool->LRU_old_len;
 		new_len = 3 * (UT_LIST_GET_LEN(buf_pool->LRU) / 8);
 
+		ut_a(buf_pool->LRU_old->in_LRU_list);
+
 		/* Update the LRU_old pointer if necessary */
 	
 		if (old_len < new_len - BUF_LRU_OLD_TOLERANCE) {
@@ -490,7 +488,7 @@ buf_LRU_old_adjust_len(void)
 							buf_pool->LRU_old);
 			buf_pool->LRU_old_len--;
 		} else {
-			ut_ad(buf_pool->LRU_old); /* Check that we did not
+			ut_a(buf_pool->LRU_old); /* Check that we did not
 						fall out of the LRU list */
 			return;
 		}
@@ -498,9 +496,8 @@ buf_LRU_old_adjust_len(void)
 }
 
 /***********************************************************************
-Initializes the old blocks pointer in the LRU list.
-This function should be called when the LRU list grows to
-BUF_LRU_OLD_MIN_LEN length. */
+Initializes the old blocks pointer in the LRU list. This function should be
+called when the LRU list grows to BUF_LRU_OLD_MIN_LEN length. */
 static
 void
 buf_LRU_old_init(void)
@@ -508,7 +505,7 @@ buf_LRU_old_init(void)
 {
 	buf_block_t*	block;
 
-	ut_ad(UT_LIST_GET_LEN(buf_pool->LRU) == BUF_LRU_OLD_MIN_LEN);
+	ut_a(UT_LIST_GET_LEN(buf_pool->LRU) == BUF_LRU_OLD_MIN_LEN);
 
 	/* We first initialize all blocks in the LRU list as old and then use
 	the adjust function to move the LRU_old pointer to the right
@@ -517,6 +514,8 @@ buf_LRU_old_init(void)
 	block = UT_LIST_GET_FIRST(buf_pool->LRU);
 
 	while (block != NULL) {
+		ut_a(block->state == BUF_BLOCK_FILE_PAGE);
+	        ut_a(block->in_LRU_list);
 		block->old = TRUE;
 		block = UT_LIST_GET_NEXT(LRU, block);
 	}
@@ -539,6 +538,9 @@ buf_LRU_remove_block(
 	ut_ad(block);
 	ut_ad(mutex_own(&(buf_pool->mutex)));
 		
+	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
+	ut_a(block->in_LRU_list);
+
 	/* If the LRU_old pointer is defined and points to just this block,
 	move it backward one step */
 
@@ -552,11 +554,12 @@ buf_LRU_remove_block(
 		(buf_pool->LRU_old)->old = TRUE;
 
 		buf_pool->LRU_old_len++;
-		ut_ad(buf_pool->LRU_old);
+		ut_a(buf_pool->LRU_old);
 	}
 
 	/* Remove the block from the LRU list */
 	UT_LIST_REMOVE(LRU, buf_pool->LRU, block);
+	block->in_LRU_list = FALSE;
 
 	if (srv_use_awe && block->frame) {
 		/* Remove from the list of mapped pages */
@@ -599,6 +602,8 @@ buf_LRU_add_block_to_end_low(
 	ut_ad(block);
 	ut_ad(mutex_own(&(buf_pool->mutex)));
 
+	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
+
 	block->old = TRUE;
 
 	last_block = UT_LIST_GET_LAST(buf_pool->LRU);
@@ -609,7 +614,9 @@ buf_LRU_add_block_to_end_low(
 		block->LRU_position = buf_pool_clock_tic();
 	}			
 
+	ut_a(!block->in_LRU_list);
 	UT_LIST_ADD_LAST(LRU, buf_pool->LRU, block);
+	block->in_LRU_list = TRUE;
 
 	if (srv_use_awe && block->frame) {
 		/* Add to the list of mapped pages */
@@ -658,6 +665,9 @@ buf_LRU_add_block_low(
 	ut_ad(block);
 	ut_ad(mutex_own(&(buf_pool->mutex)));
 
+	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
+	ut_a(!block->in_LRU_list);
+
 	block->old = old;
 	cl = buf_pool_clock_tic();
 
@@ -687,6 +697,8 @@ buf_LRU_add_block_low(
 		block->LRU_position = (buf_pool->LRU_old)->LRU_position;
 	}
 
+	block->in_LRU_list = TRUE;
+
 	if (UT_LIST_GET_LEN(buf_pool->LRU) > BUF_LRU_OLD_MIN_LEN) {
 
 		ut_ad(buf_pool->LRU_old);
@@ -755,9 +767,12 @@ buf_LRU_block_free_non_file_page(
 	ut_ad(mutex_own(&(buf_pool->mutex)));
 	ut_ad(block);
 	
-	ut_ad((block->state == BUF_BLOCK_MEMORY)
+	ut_a((block->state == BUF_BLOCK_MEMORY)
 	      || (block->state == BUF_BLOCK_READY_FOR_USE));
 
+	ut_a(block->n_pointers == 0);
+	ut_a(!block->in_free_list);
+
 	block->state = BUF_BLOCK_NOT_USED;
 
 #ifdef UNIV_DEBUG	
@@ -765,6 +780,7 @@ buf_LRU_block_free_non_file_page(
 	memset(block->frame, '\0', UNIV_PAGE_SIZE);
 #endif	
 	UT_LIST_ADD_FIRST(free, buf_pool->free, block);
+	block->in_free_list = TRUE;
 
 	if (srv_use_awe && block->frame) {
 		/* Add to the list of mapped pages */
@@ -788,8 +804,7 @@ buf_LRU_block_remove_hashed_page(
 	ut_ad(mutex_own(&(buf_pool->mutex)));
 	ut_ad(block);
 	
-	ut_ad(block->state == BUF_BLOCK_FILE_PAGE);
-
+	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
 	ut_a(block->io_fix == 0);
 	ut_a(block->buf_fix_count == 0);
 	ut_a(ut_dulint_cmp(block->oldest_modification, ut_dulint_zero) == 0);
@@ -802,6 +817,28 @@ buf_LRU_block_remove_hashed_page(
 	
  	buf_block_modify_clock_inc(block);
 		
+        if (block != buf_page_hash_get(block->space, block->offset)) {
+                fprintf(stderr,
+"InnoDB: Error: page %lu %lu not found from the hash table\n",
+                                 block->space,
+                                block->offset);
+                if (buf_page_hash_get(block->space, block->offset)) {
+                        fprintf(stderr,
+"InnoDB: From hash table we find block %lx of %lu %lu which is not %lx\n",
+                (ulint)buf_page_hash_get(block->space, block->offset),
+                        buf_page_hash_get(block->space, block->offset)->space,
+                        buf_page_hash_get(block->space, block->offset)->offset,
+                        (ulint)block);
+                }
+
+                buf_print();
+                buf_LRU_print();
+                buf_validate();
+                buf_LRU_validate();
+
+                ut_a(0);
+        }	
+
 	HASH_DELETE(buf_block_t, hash, buf_pool->page_hash,
 			buf_page_address_fold(block->space, block->offset),
 			block);
@@ -819,7 +856,7 @@ buf_LRU_block_free_hashed_page(
 				be in a state where it can be freed */
 {
 	ut_ad(mutex_own(&(buf_pool->mutex)));
-	ut_ad(block->state == BUF_BLOCK_REMOVE_HASH);
+	ut_a(block->state == BUF_BLOCK_REMOVE_HASH);
 
 	block->state = BUF_BLOCK_MEMORY;
 
diff --git a/innobase/buf/buf0rea.c b/innobase/buf/buf0rea.c
index 8cc379e75d8..0fa6912ba1d 100644
--- a/innobase/buf/buf0rea.c
+++ b/innobase/buf/buf0rea.c
@@ -129,6 +129,8 @@ buf_read_page_low(
 							   offset, sync);
 	}
 
+	ut_a(block->state == BUF_BLOCK_FILE_PAGE);
+
 	*err = fil_io(OS_FILE_READ | wake_later,
 			sync, space,
 			offset, 0, UNIV_PAGE_SIZE,
@@ -604,7 +606,6 @@ buf_read_ibuf_merge_pages(
 	}	
 
 	for (i = 0; i < n_stored; i++) {
-
 		if ((i + 1 == n_stored) && sync) {
 			buf_read_page_low(&err, TRUE, BUF_READ_ANY_PAGE,
 				space_ids[i], space_versions[i], page_nos[i]);