MDEV-24182 ibuf_merge_or_delete_for_page() contains dead code

The function ibuf_merge_or_delete_for_page() was always being
invoked with update_ibuf_bitmap=true ever since
commit cd623508
fixed up something after MDEV-9566.

Furthermore, the parameter page_size is never being passed as a
null pointer, and therefore it should better be a reference to
a constant object.

storage/innobase/buf/buf0buf.cc

@@ -4601,7 +4601,7 @@ buf_page_get_low(
 
 		if (!access_time && !recv_no_ibuf_operations) {
 			ibuf_merge_or_delete_for_page(
-				block, page_id, &page_size, TRUE);
+				block, page_id, page_size);
 		}
 
 		buf_pool_mutex_enter(buf_pool);
@@ -5678,7 +5678,7 @@ buf_page_create(
 	/* Delete possible entries for the page from the insert buffer:
 	such can exist if the page belonged to an index which was dropped */
 	if (!recv_recovery_is_on()) {
-		ibuf_merge_or_delete_for_page(NULL, page_id, &page_size, TRUE);
+		ibuf_merge_or_delete_for_page(NULL, page_id, page_size);
 	}
 
 	frame = block->frame;
@@ -6133,7 +6133,7 @@ buf_page_io_complete(buf_page_t* bpage, bool dblwr, bool evict)
 
 			ibuf_merge_or_delete_for_page(
 				(buf_block_t*) bpage, bpage->id,
-				&bpage->size, TRUE);
+				bpage->size);
 		}
 
 		fil_space_release_for_io(space);

storage/innobase/ibuf/ibuf0ibuf.cc

@@ -4384,16 +4384,12 @@ exist entries for such a page if the page belonged to an index which
 subsequently was dropped.
 @param[in,out]	block			if page has been read from disk,
 pointer to the page x-latched, else NULL
-@param[in]	page_id			page id of the index page
-@param[in]	update_ibuf_bitmap	normally this is set to TRUE, but
-if we have deleted or are deleting the tablespace, then we naturally do not
-want to update a non-existent bitmap page */
+@param[in]	page_id			page id of the index page */
 void
 ibuf_merge_or_delete_for_page(
 	buf_block_t*		block,
 	const page_id_t		page_id,
-	const page_size_t*	page_size,
-	ibool			update_ibuf_bitmap)
+	const page_size_t&	page_size)
 {
 	btr_pcur_t	pcur;
 #ifdef UNIV_IBUF_DEBUG
@@ -4417,81 +4413,50 @@ ibuf_merge_or_delete_for_page(
 		return;
 	}
 
-	/* We cannot refer to page_size in the following, because it is passed
-	as NULL (it is unknown) when buf_read_ibuf_merge_pages() is merging
-	(discarding) changes for a dropped tablespace. When block != NULL or
-	update_ibuf_bitmap is specified, then page_size must be known.
-	That is why we will repeat the check below, with page_size in
-	place of univ_page_size. Passing univ_page_size assumes that the
-	uncompressed page size always is a power-of-2 multiple of the
-	compressed page size. */
-
-	if (ibuf_fixed_addr_page(page_id, univ_page_size)
-	    || fsp_descr_page(page_id, univ_page_size)) {
+	if (ibuf_fixed_addr_page(page_id, page_size)
+	    || fsp_descr_page(page_id, page_size)) {
 		return;
 	}
 
-	fil_space_t*	space;
-
-	if (update_ibuf_bitmap) {
-
-		ut_ad(page_size != NULL);
-
-		if (ibuf_fixed_addr_page(page_id, *page_size)
-		    || fsp_descr_page(page_id, *page_size)) {
-			return;
-		}
+	fil_space_t* space = fil_space_acquire_silent(page_id.space());
 
-		space = fil_space_acquire_silent(page_id.space());
-
-		if (UNIV_UNLIKELY(!space)) {
-			/* Do not try to read the bitmap page from the
-			non-existent tablespace, delete the ibuf records */
-			block = NULL;
-			update_ibuf_bitmap = FALSE;
-		} else {
-			page_t*	bitmap_page = NULL;
-			ulint	bitmap_bits = 0;
+	if (UNIV_UNLIKELY(!space)) {
+		block = NULL;
+	} else {
+		page_t*	bitmap_page = NULL;
+		ulint	bitmap_bits = 0;
 
-			ibuf_mtr_start(&mtr);
+		ibuf_mtr_start(&mtr);
 
-			bitmap_page = ibuf_bitmap_get_map_page(
-				page_id, *page_size, &mtr);
+		bitmap_page = ibuf_bitmap_get_map_page(
+			page_id, page_size, &mtr);
 
-			if (bitmap_page &&
-			    fil_page_get_type(bitmap_page) != FIL_PAGE_TYPE_ALLOCATED) {
-				bitmap_bits = ibuf_bitmap_page_get_bits(
-				bitmap_page, page_id, *page_size,
-					IBUF_BITMAP_BUFFERED, &mtr);
-			}
+		if (bitmap_page &&
+		    fil_page_get_type(bitmap_page) != FIL_PAGE_TYPE_ALLOCATED) {
+			bitmap_bits = ibuf_bitmap_page_get_bits(
+				bitmap_page, page_id, page_size,
+				IBUF_BITMAP_BUFFERED, &mtr);
+		}
 
-			ibuf_mtr_commit(&mtr);
+		ibuf_mtr_commit(&mtr);
 
-			if (!bitmap_bits) {
-				/* No changes are buffered for this page. */
-
-				fil_space_release(space);
-				if (UNIV_UNLIKELY(srv_shutdown_state)
-				    && !srv_fast_shutdown
-				    && (!block
-					|| btr_page_get_index_id(block->frame)
-					!= DICT_IBUF_ID_MIN + IBUF_SPACE_ID)) {
-					/* Prevent an infinite loop on slow
-					shutdown, in case the bitmap bits are
-					wrongly clear even though buffered
-					changes exist. */
-					ibuf_delete_recs(page_id);
-				}
-				return;
+		if (!bitmap_bits) {
+			/* No changes are buffered for this page. */
+
+			fil_space_release(space);
+			if (UNIV_UNLIKELY(srv_shutdown_state)
+			    && !srv_fast_shutdown
+			    && (!block
+				|| btr_page_get_index_id(block->frame)
+				!= DICT_IBUF_ID_MIN + IBUF_SPACE_ID)) {
+				/* Prevent an infinite loop on slow
+				shutdown, in case the bitmap bits are
+				wrongly clear even though buffered
+				changes exist. */
+				ibuf_delete_recs(page_id);
 			}
+			return;
 		}
-	} else if (block != NULL
-		   && (ibuf_fixed_addr_page(page_id, *page_size)
-		       || fsp_descr_page(page_id, *page_size))) {
-
-		return;
-	} else {
-		space = NULL;
 	}
 
 	mem_heap_t* heap = mem_heap_create(512);
@@ -4541,7 +4506,7 @@ ibuf_merge_or_delete_for_page(
 	if (block != NULL) {
 		ibool success;
 
-		mtr.set_named_space(page_id.space());
+		mtr.set_named_space(space);
 
 		success = buf_page_get_known_nowait(
 			RW_X_LATCH, block,
@@ -4556,8 +4521,8 @@ ibuf_merge_or_delete_for_page(
 		the block is io-fixed. Other threads must not try to
 		latch an io-fixed block. */
 		buf_block_dbg_add_level(block, SYNC_IBUF_TREE_NODE);
-	} else if (update_ibuf_bitmap) {
-		mtr.set_named_space(page_id.space());
+	} else if (space) {
+		mtr.set_named_space(space);
 	}
 
 	if (!btr_pcur_is_on_user_rec(&pcur)) {
@@ -4658,7 +4623,7 @@ ibuf_merge_or_delete_for_page(
 				ibuf_btr_pcur_commit_specify_mtr(&pcur, &mtr);
 
 				ibuf_mtr_start(&mtr);
-				mtr.set_named_space(page_id.space());
+				mtr.set_named_space(space);
 
 				success = buf_page_get_known_nowait(
 					RW_X_LATCH, block,
@@ -4714,26 +4679,26 @@ ibuf_merge_or_delete_for_page(
 	}
 
 reset_bit:
-	if (update_ibuf_bitmap) {
+	if (space) {
 		page_t*	bitmap_page;
 
-		bitmap_page = ibuf_bitmap_get_map_page(page_id, *page_size,
+		bitmap_page = ibuf_bitmap_get_map_page(page_id, page_size,
 						       &mtr);
 
 		ibuf_bitmap_page_set_bits(
-			bitmap_page, page_id, *page_size,
+			bitmap_page, page_id, page_size,
 			IBUF_BITMAP_BUFFERED, FALSE, &mtr);
 
 		if (block != NULL) {
 			ulint old_bits = ibuf_bitmap_page_get_bits(
-				bitmap_page, page_id, *page_size,
+				bitmap_page, page_id, page_size,
 				IBUF_BITMAP_FREE, &mtr);
 
 			ulint new_bits = ibuf_index_page_calc_free(block);
 
 			if (old_bits != new_bits) {
 				ibuf_bitmap_page_set_bits(
-					bitmap_page, page_id, *page_size,
+					bitmap_page, page_id, page_size,
 					IBUF_BITMAP_FREE, new_bits, &mtr);
 			}
 		}

storage/innobase/include/ibuf0ibuf.h

@@ -342,16 +342,12 @@ exist entries for such a page if the page belonged to an index which
 subsequently was dropped.
 @param[in,out]	block			if page has been read from disk,
 pointer to the page x-latched, else NULL
-@param[in]	page_id			page id of the index page
-@param[in]	update_ibuf_bitmap	normally this is set to TRUE, but
-if we have deleted or are deleting the tablespace, then we naturally do not
-want to update a non-existent bitmap page */
+@param[in]	page_id			page id of the index page */
 void
 ibuf_merge_or_delete_for_page(
 	buf_block_t*		block,
 	const page_id_t		page_id,
-	const page_size_t*	page_size,
-	ibool			update_ibuf_bitmap);
+	const page_size_t&	page_size);
 
 /*********************************************************************//**
 Deletes all entries in the insert buffer for a given space id. This is used

storage/innobase/log/log0recv.cc

@@ -320,8 +320,7 @@ class mlog_init_t
 				    &mtr, NULL)) {
 				mutex_exit(&recv_sys->mutex);
 				ibuf_merge_or_delete_for_page(
-					block, i->first,
-					&block->page.size, true);
+					block, i->first, block->page.size);
 				mtr.commit();
 				mtr.start();
 				mutex_enter(&recv_sys->mutex);