postgres.git / summary / log / commit / refs

commit    2a2e1b470b9b4e9c7d76bc227db02a2efbb57473
Author:   Andres Freund <andres@anarazel.de>
Date:     Wed Oct 08 18:34:30 2025 +0000

    bufmgr: Fix signedness of mask variable in BufferSync()
    
    BM_PERMANENT is defined as 1U<<31, which is a negative number when interpreted
    as a signed integer. Unfortunately the mask variable in BufferSync() was
    signed. This has been wrong for a long time, but failed to fail, due to
    integer conversion rules.
    
    However, in an upcoming patch the width of the state variable will be
    increased, with the wrong signedness leading to never flushing permanent
    buffers - luckily caught in a test.
    
    It seems better to fix this separately, instead of doing so as part of a
    large, otherwise mechanical, patch.
    
    Reviewed-by: Matthias van de Meent <boekewurm+postgres@gmail.com>
    Discussion: https://postgr.es/m/fvfmkr5kk4nyex56ejgxj3uzi63isfxovp2biecb4bspbjrze7@az2pljabhnff


 src/backend/storage/buffer/bufmgr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index fd462a25beb..8ee7d3b441b 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -3321,7 +3321,7 @@ BufferSync(int flags)
 	Oid			last_tsid;
 	binaryheap *ts_heap;
 	int			i;
-	int			mask = BM_DIRTY;
+	uint32		mask = BM_DIRTY;
 	WritebackContext wb_context;
 
 	/*


[parent: 3c2b97b29ee3]