From c623e8593ec4ee6987f3cd9350ced7caf8526ed2 Mon Sep 17 00:00:00 2001 From: Melanie Plageman Date: Tue, 18 Feb 2025 09:28:10 -0500 Subject: [PATCH] Reduce scope of heap vacuum per_buffer_data Move lazy_scan_heap()'s per_buffer_data variable into a tighter scope. In lazy_scan_heap()'s phase I heap vacuuming, the read stream API returns a pointer to the next block number to vacuum. As long as read_stream_next_buffer() returns a valid buffer, per_buffer_data should always be valid. Move per_buffer_data into a tighter scope and make sure it is reset to NULL on each iteration so that we get a core dump instead of bogus data from a previous block if something goes wrong in the read stream API. Suggested-by: Tom Lane Discussion: https://postgr.es/m/626104.1739729538%40sss.pgh.pa.us --- src/backend/access/heap/vacuumlazy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c index 911f68b413d..1af18a78a2b 100644 --- a/src/backend/access/heap/vacuumlazy.c +++ b/src/backend/access/heap/vacuumlazy.c @@ -1192,7 +1192,6 @@ lazy_scan_heap(LVRelState *vacrel) BlockNumber rel_pages = vacrel->rel_pages, blkno = 0, next_fsm_block_to_vacuum = 0; - void *per_buffer_data = NULL; BlockNumber orig_eager_scan_success_limit = vacrel->eager_scan_remaining_successes; /* for logging */ Buffer vmbuffer = InvalidBuffer; @@ -1231,6 +1230,7 @@ lazy_scan_heap(LVRelState *vacrel) Page page; uint8 blk_info = 0; bool has_lpdead_items; + void *per_buffer_data = NULL; bool vm_page_frozen = false; bool got_cleanup_lock = false;