v36-0001-Remove-BufferAccessStrategyData-current_was_in_r.patch

From 4746ef5834de99836f81be8ffd322d139c940a25 Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Thu, 13 Oct 2022 11:03:05 -0700
Subject: [PATCH v36 1/5] Remove BufferAccessStrategyData->current_was_in_ring

It is a duplication of StrategyGetBuffer->from_ring.
---
 src/backend/storage/buffer/bufmgr.c   |  2 +-
 src/backend/storage/buffer/freelist.c | 15 ++-------------
 src/include/storage/buf_internals.h   |  2 +-
 3 files changed, 4 insertions(+), 15 deletions(-)

diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 6b95381481..4e7b0b31bb 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -1254,7 +1254,7 @@ BufferAlloc(SMgrRelation smgr, char relpersistence, ForkNumber forkNum,
 					UnlockBufHdr(buf, buf_state);
 
 					if (XLogNeedsFlush(lsn) &&
-						StrategyRejectBuffer(strategy, buf))
+						StrategyRejectBuffer(strategy, buf, from_ring))
 					{
 						/* Drop lock/pin and loop around for another buffer */
 						LWLockRelease(BufferDescriptorGetContentLock(buf));
diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c
index 990e081aae..64728bd7ce 100644
--- a/src/backend/storage/buffer/freelist.c
+++ b/src/backend/storage/buffer/freelist.c
@@ -81,12 +81,6 @@ typedef struct BufferAccessStrategyData
 	 */
 	int			current;
 
-	/*
-	 * True if the buffer just returned by StrategyGetBuffer had been in the
-	 * ring already.
-	 */
-	bool		current_was_in_ring;
-
 	/*
 	 * Array of buffer numbers.  InvalidBuffer (that is, zero) indicates we
 	 * have not yet selected a buffer for this ring slot.  For allocation
@@ -625,10 +619,7 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state)
 	 */
 	bufnum = strategy->buffers[strategy->current];
 	if (bufnum == InvalidBuffer)
-	{
-		strategy->current_was_in_ring = false;
 		return NULL;
-	}
 
 	/*
 	 * If the buffer is pinned we cannot use it under any circumstances.
@@ -644,7 +635,6 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state)
 	if (BUF_STATE_GET_REFCOUNT(local_buf_state) == 0
 		&& BUF_STATE_GET_USAGECOUNT(local_buf_state) <= 1)
 	{
-		strategy->current_was_in_ring = true;
 		*buf_state = local_buf_state;
 		return buf;
 	}
@@ -654,7 +644,6 @@ GetBufferFromRing(BufferAccessStrategy strategy, uint32 *buf_state)
 	 * Tell caller to allocate a new buffer with the normal allocation
 	 * strategy.  He'll then replace this ring element via AddBufferToRing.
 	 */
-	strategy->current_was_in_ring = false;
 	return NULL;
 }
 
@@ -682,14 +671,14 @@ AddBufferToRing(BufferAccessStrategy strategy, BufferDesc *buf)
  * if this buffer should be written and re-used.
  */
 bool
-StrategyRejectBuffer(BufferAccessStrategy strategy, BufferDesc *buf)
+StrategyRejectBuffer(BufferAccessStrategy strategy, BufferDesc *buf, bool from_ring)
 {
 	/* We only do this in bulkread mode */
 	if (strategy->btype != BAS_BULKREAD)
 		return false;
 
 	/* Don't muck with behavior of normal buffer-replacement strategy */
-	if (!strategy->current_was_in_ring ||
+	if (!from_ring ||
 		strategy->buffers[strategy->current] != BufferDescriptorGetBuffer(buf))
 		return false;
 
diff --git a/src/include/storage/buf_internals.h b/src/include/storage/buf_internals.h
index 406db6be78..b75481450d 100644
--- a/src/include/storage/buf_internals.h
+++ b/src/include/storage/buf_internals.h
@@ -395,7 +395,7 @@ extern BufferDesc *StrategyGetBuffer(BufferAccessStrategy strategy,
 									 uint32 *buf_state);
 extern void StrategyFreeBuffer(BufferDesc *buf);
 extern bool StrategyRejectBuffer(BufferAccessStrategy strategy,
-								 BufferDesc *buf);
+								 BufferDesc *buf, bool from_ring);
 
 extern int	StrategySyncStart(uint32 *complete_passes, uint32 *num_buf_alloc);
 extern void StrategyNotifyBgWriter(int bgwprocno);
-- 
2.34.1