MDEV-12266: Clean up btr_search_drop_page_hash_when_freed()

Remove the parameter page_size, and pass a dummy page size
to buf_page_get_gen() along with BUF_PEEK_IF_IN_POOL.

storage/innobase/btr/btr0sea.cc

@@ -1280,12 +1280,8 @@ btr_search_drop_page_hash_index(buf_block_t* block)
 /** Drop any adaptive hash index entries that may point to an index
 page that may be in the buffer pool, when a page is evicted from the
 buffer pool or freed in a file segment.
-@param[in]	page_id		page id
-@param[in]	page_size	page size */
-void
-btr_search_drop_page_hash_when_freed(
-	const page_id_t&	page_id,
-	const page_size_t&	page_size)
+@param[in]	page_id		page id */
+void btr_search_drop_page_hash_when_freed(const page_id_t& page_id)
 {
 	buf_block_t*	block;
 	mtr_t		mtr;
@@ -1301,7 +1297,7 @@ btr_search_drop_page_hash_when_freed(
 	are possibly holding, we cannot s-latch the page, but must
 	(recursively) x-latch it, even though we are only reading. */
 
-	block = buf_page_get_gen(page_id, page_size, RW_X_LATCH, NULL,
+	block = buf_page_get_gen(page_id, univ_page_size, RW_X_LATCH, NULL,
 				 BUF_PEEK_IF_IN_POOL, __FILE__, __LINE__,
 				 &mtr, &err);
 

storage/innobase/buf/buf0buf.cc

@@ -4247,6 +4247,10 @@ buf_page_get_gen(
 		replace any old pages, which were not evicted during DISCARD.
 		Skip the assertion on space_page_size. */
 		break;
+	case BUF_PEEK_IF_IN_POOL:
+		/* In this mode, the caller may pass a dummy page size,
+		because it does not really matter. */
+		break;
 	default:
 		ut_error;
 	case BUF_GET_NO_LATCH:
@@ -4254,7 +4258,6 @@ buf_page_get_gen(
 		/* fall through */
 	case BUF_GET:
 	case BUF_GET_IF_IN_POOL:
-	case BUF_PEEK_IF_IN_POOL:
 	case BUF_GET_IF_IN_POOL_OR_WATCH:
 	case BUF_GET_POSSIBLY_FREED:
 		bool			found;

storage/innobase/buf/buf0lru.cc

@@ -224,14 +224,12 @@ buf_LRU_evict_from_unzip_LRU(
 /** Attempts to drop page hash index on a batch of pages belonging to a
 particular space id.
 @param[in]	space_id	space id
-@param[in]	page_size	page size
 @param[in]	arr		array of page_no
 @param[in]	count		number of entries in array */
 static
 void
 buf_LRU_drop_page_hash_batch(
 	ulint			space_id,
-	const page_size_t&	page_size,
 	const ulint*		arr,
 	ulint			count)
 {
@@ -247,7 +245,7 @@ buf_LRU_drop_page_hash_batch(
 		in the tablespace, and a previous DROP TABLE would have
 		already removed the AHI entries. */
 		btr_search_drop_page_hash_when_freed(
-			page_id_t(space_id, *arr), page_size);
+			page_id_t(space_id, *arr));
 	}
 }
 
@@ -263,15 +261,6 @@ buf_LRU_drop_page_hash_for_tablespace(
 	buf_pool_t*	buf_pool,	/*!< in: buffer pool instance */
 	ulint		id)		/*!< in: space id */
 {
-	bool			found;
-	const page_size_t	page_size(fil_space_get_page_size(id, &found));
-
-	if (!found) {
-		/* Somehow, the tablespace does not exist.  Nothing to drop. */
-		ut_ad(0);
-		return;
-	}
-
 	ulint*	page_arr = static_cast<ulint*>(ut_malloc_nokey(
 			sizeof(ulint) * BUF_LRU_DROP_SEARCH_SIZE));
 
@@ -338,8 +327,7 @@ buf_LRU_drop_page_hash_for_tablespace(
 		the latching order. */
 		buf_pool_mutex_exit(buf_pool);
 
-		buf_LRU_drop_page_hash_batch(
-			id, page_size, page_arr, num_entries);
+		buf_LRU_drop_page_hash_batch(id, page_arr, num_entries);
 
 		num_entries = 0;
 
@@ -371,7 +359,7 @@ buf_LRU_drop_page_hash_for_tablespace(
 	buf_pool_mutex_exit(buf_pool);
 
 	/* Drop any remaining batch of search hashed pages. */
-	buf_LRU_drop_page_hash_batch(id, page_size, page_arr, num_entries);
+	buf_LRU_drop_page_hash_batch(id, page_arr, num_entries);
 	ut_free(page_arr);
 }
 #endif /* BTR_CUR_HASH_ADAPT */

storage/innobase/fsp/fsp0fsp.cc

@@ -2973,7 +2973,7 @@ fseg_free_page_low(
 
 	if (ahi) {
 		btr_search_drop_page_hash_when_freed(
-			page_id_t(space->id, offset), page_size);
+			page_id_t(space->id, offset));
 	}
 #endif /* BTR_CUR_HASH_ADAPT */
 
@@ -3177,8 +3177,7 @@ fseg_free_extent(
 
 				btr_search_drop_page_hash_when_freed(
 					page_id_t(space->id,
-						  first_page_in_extent + i),
-					page_size);
+						  first_page_in_extent + i));
 			}
 		}
 	}

storage/innobase/include/btr0sea.h

@@ -131,10 +131,7 @@ page that may be in the buffer pool, when a page is evicted from the
 buffer pool or freed in a file segment.
 @param[in]	page_id		page id
 @param[in]	page_size	page size */
-void
-btr_search_drop_page_hash_when_freed(
-	const page_id_t&	page_id,
-	const page_size_t&	page_size);
+void btr_search_drop_page_hash_when_freed(const page_id_t& page_id);
 
 /** Updates the page hash index when a single record is inserted on a page.
 @param[in]	cursor	cursor which was positioned to the place to insert