From 491f65d6b356734065a190da3311391ffc74d08e Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Sun, 9 Mar 2025 19:55:05 -0400
Subject: [PATCH v2.6 18/34] localbuf: Introduce TerminateLocalBufferIO()

Previously TerminateLocalBufferIO() was open-coded in multiple places, which
doesn't seem like a great idea.

Author:
Reviewed-by:
Discussion: https://postgr.es/m/
Backpatch:
---
 src/include/storage/buf_internals.h   |  2 ++
 src/backend/storage/buffer/bufmgr.c   | 32 ++++++++-------------------
 src/backend/storage/buffer/localbuf.c | 28 +++++++++++++++++++++--
 3 files changed, 37 insertions(+), 25 deletions(-)

diff --git a/src/include/storage/buf_internals.h b/src/include/storage/buf_internals.h
index 8b32fb108b0..4611a60d3e0 100644
--- a/src/include/storage/buf_internals.h
+++ b/src/include/storage/buf_internals.h
@@ -471,6 +471,8 @@ extern BlockNumber ExtendBufferedRelLocal(BufferManagerRelation bmr,
 										  Buffer *buffers,
 										  uint32 *extended_by);
 extern void MarkLocalBufferDirty(Buffer buffer);
+extern void TerminateLocalBufferIO(BufferDesc *bufHdr, bool clear_dirty,
+								   uint32 set_flag_bits);
 extern void DropRelationLocalBuffers(RelFileLocator rlocator,
 									 ForkNumber forkNum,
 									 BlockNumber firstDelBlock);
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 75a928e802a..ead562249d3 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -1072,19 +1072,11 @@ ZeroAndLockBuffer(Buffer buffer, ReadBufferMode mode, bool already_valid)
 		if (!isLocalBuf)
 			LWLockAcquire(BufferDescriptorGetContentLock(bufHdr), LW_EXCLUSIVE);
 
+		/* Set BM_VALID, terminate IO, and wake up any waiters */
 		if (isLocalBuf)
-		{
-			/* Only need to adjust flags */
-			uint32		buf_state = pg_atomic_read_u32(&bufHdr->state);
-
-			buf_state |= BM_VALID;
-			pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
-		}
+			TerminateLocalBufferIO(bufHdr, false, BM_VALID);
 		else
-		{
-			/* Set BM_VALID, terminate IO, and wake up any waiters */
 			TerminateBufferIO(bufHdr, false, BM_VALID, true);
-		}
 	}
 	else if (!isLocalBuf)
 	{
@@ -1608,19 +1600,11 @@ WaitReadBuffers(ReadBuffersOperation *operation)
 									relpath(operation->smgr->smgr_rlocator, forknum).str)));
 			}
 
-			/* Terminate I/O and set BM_VALID. */
+			/* Set BM_VALID, terminate IO, and wake up any waiters */
 			if (persistence == RELPERSISTENCE_TEMP)
-			{
-				uint32		buf_state = pg_atomic_read_u32(&bufHdr->state);
-
-				buf_state |= BM_VALID;
-				pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
-			}
+				TerminateLocalBufferIO(bufHdr, false, BM_VALID);
 			else
-			{
-				/* Set BM_VALID, terminate IO, and wake up any waiters */
 				TerminateBufferIO(bufHdr, false, BM_VALID, true);
-			}
 
 			/* Report I/Os as completing individually. */
 			TRACE_POSTGRESQL_BUFFER_READ_DONE(forknum, io_first_block + j,
@@ -4564,8 +4548,7 @@ FlushRelationBuffers(Relation rel)
 										IOCONTEXT_NORMAL, IOOP_WRITE,
 										io_start, 1, BLCKSZ);
 
-				buf_state &= ~(BM_DIRTY | BM_JUST_DIRTIED);
-				pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
+				TerminateLocalBufferIO(bufHdr, true, 0);
 
 				pgBufferUsage.local_blks_written++;
 
@@ -5652,8 +5635,11 @@ TerminateBufferIO(BufferDesc *buf, bool clear_dirty, uint32 set_flag_bits,
 	buf_state = LockBufHdr(buf);
 
 	Assert(buf_state & BM_IO_IN_PROGRESS);
+	buf_state &= ~BM_IO_IN_PROGRESS;
+
+	/* Clear earlier errors, if this IO failed, it'll be marked again */
+	buf_state &= ~BM_IO_ERROR;
 
-	buf_state &= ~(BM_IO_IN_PROGRESS | BM_IO_ERROR);
 	if (clear_dirty && !(buf_state & BM_JUST_DIRTIED))
 		buf_state &= ~(BM_DIRTY | BM_CHECKPOINT_NEEDED);
 
diff --git a/src/backend/storage/buffer/localbuf.c b/src/backend/storage/buffer/localbuf.c
index 4444228d645..ce3f8c78c18 100644
--- a/src/backend/storage/buffer/localbuf.c
+++ b/src/backend/storage/buffer/localbuf.c
@@ -259,8 +259,7 @@ GetLocalVictimBuffer(void)
 								IOOP_WRITE, io_start, 1, BLCKSZ);
 
 		/* Mark not-dirty now in case we error out below */
-		buf_state &= ~BM_DIRTY;
-		pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
+		TerminateLocalBufferIO(bufHdr, true, 0);
 
 		pgBufferUsage.local_blks_written++;
 	}
@@ -483,6 +482,31 @@ MarkLocalBufferDirty(Buffer buffer)
 	pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
 }
 
+/*
+ * Like TerminateBufferIO, but for local buffers
+ */
+void
+TerminateLocalBufferIO(BufferDesc *bufHdr, bool clear_dirty, uint32 set_flag_bits)
+{
+	/* Only need to adjust flags */
+	uint32		buf_state = pg_atomic_read_u32(&bufHdr->state);
+
+	/* BM_IO_IN_PROGRESS isn't currently used for local buffers */
+
+	/* Clear earlier errors, if this IO failed, it'll be marked again */
+	buf_state &= ~BM_IO_ERROR;
+
+	if (clear_dirty)
+		buf_state &= ~BM_DIRTY;
+
+	buf_state |= set_flag_bits;
+	pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
+
+	/* local buffers don't track IO using resowners */
+
+	/* local buffers don't use the IO CV, as no other process can see buffer */
+}
+
 /*
  * InvalidateLocalBuffer -- mark a local buffer invalid.
  *
-- 
2.48.1.76.g4e746b1a31.dirty