MDEV-15528: Simplify buf_page_create()bb-10.5-MDEV-15528-latest

buf_page_create(): Let the callers assign buf_page_t::status.
Every caller should eventually invoke mtr_t::init().

fsp_page_create(): Remove the unused mtr_t parameter.

In all other callers of buf_page_create() except fsp_page_create(),
before invoking mtr_t::init(), invoke
mtr_t::sx_latch_at_savepoint() or mtr_t::x_latch_at_savepoint().

mtr_t::init(): Initialize buf_page_t::status also for the temporary
tablespace (when redo logging is disabled), to avoid assertion failures.

4 files changed, 30 insertions, 42 deletions

diff --git a/storage/innobase/buf/buf0buf.cc b/storage/innobase/buf/buf0buf.cc
index 3d90380eaf3..7ae510a8851 100644
--- a/storage/innobase/buf/buf0buf.cc
+++ b/storage/innobase/buf/buf0buf.cc
@@ -4930,21 +4930,20 @@ buf_page_create(
 	if (block
 	    && buf_page_in_file(&block->page)
 	    && !buf_pool_watch_is_sentinel(&block->page)) {
-		BPageMutex*	block_mutex = buf_page_get_mutex(&block->page);
-		mutex_enter(block_mutex);
-
 		/* Page can be found in buf_pool */
 		mutex_exit(&buf_pool->mutex);
 		rw_lock_x_unlock(hash_lock);
 
-		block->page.status = buf_page_t::NORMAL;
-		mutex_exit(block_mutex);
-
 		buf_block_free(free_block);
 
 		if (!recv_recovery_is_on()) {
-			return buf_page_get_with_no_latch(page_id, zip_size,
-							  mtr);
+			/* FIXME: Remove the redundant lookup and avoid
+			the unnecessary invocation of buf_zip_decompress().
+			We may have to convert buf_page_t to buf_block_t,
+			but we are going to initialize the page. */
+			return buf_page_get_gen(page_id, zip_size, RW_NO_LATCH,
+						block, BUF_GET_POSSIBLY_FREED,
+						__FILE__, __LINE__, mtr);
 		}
 
 		mutex_exit(&recv_sys.mutex);
diff --git a/storage/innobase/fsp/fsp0fsp.cc b/storage/innobase/fsp/fsp0fsp.cc
index 99f17f9224d..c47a1d0a95c 100644
--- a/storage/innobase/fsp/fsp0fsp.cc
+++ b/storage/innobase/fsp/fsp0fsp.cc
@@ -554,8 +554,10 @@ void fsp_header_init(fil_space_t* space, ulint size, mtr_t* mtr)
 	const ulint zip_size = space->zip_size();
 
 	mtr_x_lock_space(space, mtr);
+
+	const auto savepoint = mtr->get_savepoint();
 	buf_block_t* block = buf_page_create(page_id, zip_size, mtr);
-	buf_page_get(page_id, zip_size, RW_SX_LATCH, mtr);
+	mtr->sx_latch_at_savepoint(savepoint, block);
 	buf_block_dbg_add_level(block, SYNC_FSP_PAGE);
 
 	space->size_in_header = size;
@@ -873,16 +875,12 @@ fsp_fill_free_list(
 			pages should be ignored. */
 
 			if (i > 0) {
-				const page_id_t	page_id(space->id, i);
-
-				block = buf_page_create(
-					page_id, zip_size, mtr);
-
-				buf_page_get(
-					page_id, zip_size, RW_SX_LATCH, mtr);
+				const auto savepoint = mtr->get_savepoint();
+				block= buf_page_create(page_id_t(space->id, i),
+						       zip_size, mtr);
+				mtr->sx_latch_at_savepoint(savepoint, block);
 
 				buf_block_dbg_add_level(block, SYNC_FSP_PAGE);
-
 				fsp_init_file_page(space, block, mtr);
 				mtr->write<2>(*block,
 					      FIL_PAGE_TYPE + block->frame,
@@ -900,17 +898,11 @@ fsp_fill_free_list(
 				ibuf_mtr.start();
 				ibuf_mtr.set_named_space(space);
 
-				const page_id_t	page_id(
-					space->id,
-					i + FSP_IBUF_BITMAP_OFFSET);
-
 				block = buf_page_create(
-					page_id, zip_size, &ibuf_mtr);
-
-				buf_page_get(
-					page_id, zip_size, RW_SX_LATCH,
-					&ibuf_mtr);
-
+					page_id_t(space->id,
+						  i + FSP_IBUF_BITMAP_OFFSET),
+					zip_size, &ibuf_mtr);
+				ibuf_mtr.sx_latch_at_savepoint(0, block);
 				buf_block_dbg_add_level(block, SYNC_FSP_PAGE);
 
 				fsp_init_file_page(space, block, &ibuf_mtr);
@@ -1060,8 +1052,7 @@ fsp_alloc_from_free_frag(buf_block_t *header, buf_block_t *xdes, xdes_t *descr,
 @param[in,out]	space		tablespace
 @param[in]	offset		page number of the allocated page
 @param[in]	rw_latch	RW_SX_LATCH, RW_X_LATCH
-@param[in,out]	mtr		mini-transaction of the allocation
-@param[in,out]	init_mtr	mini-transaction for initializing the page
+@param[in,out]	mtr		mini-transaction
 @return block, initialized */
 static
 buf_block_t*
@@ -1069,13 +1060,13 @@ fsp_page_create(
 	fil_space_t*		space,
 	page_no_t		offset,
 	rw_lock_type_t		rw_latch,
-	mtr_t*			mtr,
-	mtr_t*			init_mtr)
+	mtr_t*			mtr)
 {
 	buf_block_t*	block = buf_page_create(page_id_t(space->id, offset),
-						space->zip_size(), init_mtr);
+						space->zip_size(), mtr);
 
-	/* Mimic buf_page_get(), but avoid the buf_pool->page_hash lookup. */
+	/* The latch may already have been acquired, so we cannot invoke
+	mtr_t::x_latch_at_savepoint() or mtr_t::sx_latch_at_savepoint(). */
 	mtr_memo_type_t memo;
 
 	if (rw_latch == RW_X_LATCH) {
@@ -1087,9 +1078,9 @@ fsp_page_create(
 		memo = MTR_MEMO_PAGE_SX_FIX;
 	}
 
-	mtr_memo_push(init_mtr, block, memo);
+	mtr_memo_push(mtr, block, memo);
 	buf_block_buf_fix_inc(block, __FILE__, __LINE__);
-	fsp_init_file_page(space, block, init_mtr);
+	fsp_init_file_page(space, block, mtr);
 
 	return(block);
 }
@@ -1202,7 +1193,7 @@ fsp_alloc_free_page(
 	}
 
 	fsp_alloc_from_free_frag(block, xdes, descr, free, mtr);
-	return fsp_page_create(space, page_no, rw_latch, mtr, init_mtr);
+	return fsp_page_create(space, page_no, rw_latch, init_mtr);
 }
 
 /** Frees a single page of a space.
@@ -2233,7 +2224,7 @@ got_hinted_page:
 				    xdes, mtr);
 	}
 
-	return fsp_page_create(space, ret_page, rw_latch, mtr, init_mtr);
+	return fsp_page_create(space, ret_page, rw_latch, init_mtr);
 }
 
 /**********************************************************************//**
diff --git a/storage/innobase/include/buf0buf.h b/storage/innobase/include/buf0buf.h
index 614da25dd13..3afb6e49431 100644
--- a/storage/innobase/include/buf0buf.h
+++ b/storage/innobase/include/buf0buf.h
@@ -372,10 +372,7 @@ FILE_PAGE (the other is buf_page_get_gen).
 @param[in,out]	mtr		mini-transaction
 @return pointer to the block, page bufferfixed */
 buf_block_t*
-buf_page_create(
-	const page_id_t		page_id,
-	ulint			zip_size,
-	mtr_t*			mtr);
+buf_page_create(const page_id_t page_id, ulint zip_size, mtr_t *mtr);
 
 /********************************************************************//**
 Releases a compressed-only page acquired with buf_page_get_zip(). */
diff --git a/storage/innobase/include/mtr0log.h b/storage/innobase/include/mtr0log.h
index a6a8f696b87..29765faa017 100644
--- a/storage/innobase/include/mtr0log.h
+++ b/storage/innobase/include/mtr0log.h
@@ -502,6 +502,8 @@ inline void mtr_t::memcpy(const buf_block_t &b, void *dest, const void *str,
 @param[in,out]        b       buffer page */
 inline void mtr_t::init(buf_block_t *b)
 {
+  b->page.status= buf_page_t::INIT_ON_FLUSH;
+
   if (m_log_mode != MTR_LOG_ALL)
   {
     ut_ad(m_log_mode == MTR_LOG_NONE || m_log_mode == MTR_LOG_NO_REDO);
@@ -510,7 +512,6 @@ inline void mtr_t::init(buf_block_t *b)
 
   m_log.close(log_write<INIT_PAGE>(b->page.id, &b->page));
   m_last_offset= FIL_PAGE_TYPE;
-  b->page.status= buf_page_t::INIT_ON_FLUSH;
 }
 
 /** Free a page.