postgres.git / summary / log / commit / refs

commit    c623e8593ec4ee6987f3cd9350ced7caf8526ed2
Author:   Melanie Plageman <melanieplageman@gmail.com>
Date:     Tue Feb 18 14:28:10 2025 +0000
First released in: 18.0

    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 <tgl@sss.pgh.pa.us>
    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;
 


[parent: 95ef3d902950]