From 56218fc850cdaccaeb87767c2ca8977ee2f26697 Mon Sep 17 00:00:00 2001 From: Nazir Bilal Yavuz Date: Tue, 31 Mar 2026 15:00:40 +0300 Subject: [PATCH] Set the variables that callers might read in StartReadBuffersImpl() When the first requested block is already in the buffer pool, StartRead- BuffersImpl() returned early after setting *nblocks = 1 without starting any I/O. In that path, operation->nblocks and operation->buffers were only initialised inside #ifdef USE_ASSERT_CHECKING, leaving them as zero / NULL in non-assert builds. Callers might want to inspect these values like in the AIO tests. Fix that problem by unconditionally setting operation->nblocks and operation->buffers in the early-return hit path. --- src/backend/storage/buffer/bufmgr.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c index cd21ae3fc36..e6f99ad7668 100644 --- a/src/backend/storage/buffer/bufmgr.c +++ b/src/backend/storage/buffer/bufmgr.c @@ -1457,6 +1457,10 @@ StartReadBuffersImpl(ReadBuffersOperation *operation, { *nblocks = 1; + /* Set the variables that callers might read */ + operation->buffers = buffers; + operation->nblocks = 1; + #ifdef USE_ASSERT_CHECKING /* @@ -1464,9 +1468,7 @@ StartReadBuffersImpl(ReadBuffersOperation *operation, * CheckReadBuffersOperation() work. Outside of assertions * that's not necessary when no IO is issued. */ - operation->buffers = buffers; operation->blocknum = blockNum; - operation->nblocks = 1; operation->nblocks_done = 1; CheckReadBuffersOperation(operation, true); #endif -- 2.47.3