Subject: [PATCH v28 2/5] Save the values of the callback..

From: Justin Pryzby <[email-masked]>
Date: Thu, 19 Mar 2020 15:21:22 -0500

..allowing them to be restored later, rather than setting phase=UNKNOWN.
---
 src/backend/access/heap/vacuumlazy.c | 74 +++++++++++++++++-----------
 1 file changed, 46 insertions(+), 28 deletions(-)

diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
index 768a69120b..141a50e968 100644
--- a/src/backend/access/heap/vacuumlazy.c
+++ b/src/backend/access/heap/vacuumlazy.c
@@ -378,7 +378,8 @@ static LVSharedIndStats *get_indstats(LVShared *lvshared, int n);
 static bool skip_parallel_vacuum_index(Relation indrel, LVShared *lvshared);
 static void vacuum_error_callback(void *arg);
 static void update_vacuum_error_cbarg(LVRelStats *errcbarg, int phase,
-									  BlockNumber blkno, char *indname);
+									  BlockNumber blkno, char *indname,
+									  bool free_oldindname);

 /*
@@ -892,7 +893,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 
 	/* Setup error traceback support for ereport() */
 	update_vacuum_error_cbarg(vacrelstats, VACUUM_ERRCB_PHASE_SCAN_HEAP,
-			InvalidBlockNumber, NULL);
+			InvalidBlockNumber, NULL, false);
 	errcallback.callback = vacuum_error_callback;
 	errcallback.arg = vacrelstats;
 	errcallback.previous = error_context_stack;
@@ -924,7 +925,7 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 		pgstat_progress_update_param(PROGRESS_VACUUM_HEAP_BLKS_SCANNED, blkno);
 
 		update_vacuum_error_cbarg(vacrelstats, VACUUM_ERRCB_PHASE_SCAN_HEAP,
-								  blkno, NULL);
+								  blkno, NULL, false);
 
 		if (blkno == next_unskippable_block)
 		{
@@ -1044,10 +1045,6 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 			/* Report that we are once again scanning the heap */
 			pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
 										 PROGRESS_VACUUM_PHASE_SCAN_HEAP);
-
-			/* Set the error context while continuing heap scan */
-			update_vacuum_error_cbarg(vacrelstats,
-									  VACUUM_ERRCB_PHASE_SCAN_HEAP, blkno, NULL);
 		}
 
 		/*
@@ -1494,10 +1491,6 @@ lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
 				lazy_vacuum_page(onerel, blkno, buf, 0, vacrelstats, &vmbuffer);
 				vacuumed_pages++;
 				has_dead_tuples = false;
-
-				/* Set the error context while continuing heap scan */
-				update_vacuum_error_cbarg(vacrelstats,
-					VACUUM_ERRCB_PHASE_SCAN_HEAP, blkno, NULL);
 			}
 			else
 			{
@@ -1816,14 +1809,16 @@ lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats)
 	int			npages;
 	PGRUsage	ru0;
 	Buffer		vmbuffer = InvalidBuffer;
+	LVRelStats	olderrcbarg;
 
 	/* Report that we are now vacuuming the heap */
 	pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
 								 PROGRESS_VACUUM_PHASE_VACUUM_HEAP);
 
 	/* Setup error traceback support for ereport() */
+	olderrcbarg = *vacrelstats;
 	update_vacuum_error_cbarg(vacrelstats, VACUUM_ERRCB_PHASE_VACUUM_HEAP,
-							  InvalidBlockNumber, NULL);
+							  InvalidBlockNumber, NULL, false);
 
 	pg_rusage_init(&ru0);
 	npages = 0;
@@ -1874,8 +1869,10 @@ lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats)
 
 	/* Clear the error traceback phase */
 	update_vacuum_error_cbarg(vacrelstats,
-							  VACUUM_ERRCB_PHASE_UNKNOWN, InvalidBlockNumber,
-							  NULL);
+							  olderrcbarg.phase,
+							  olderrcbarg.blkno,
+							  olderrcbarg.indname,
+							  true);
 }
 
 /*
@@ -1898,12 +1895,14 @@ lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
 	int			uncnt = 0;
 	TransactionId visibility_cutoff_xid;
 	bool		all_frozen;
+	LVRelStats	olderrcbarg;
 
 	pgstat_progress_update_param(PROGRESS_VACUUM_HEAP_BLKS_VACUUMED, blkno);
 
 	/* Setup error traceback support for ereport() */
+	olderrcbarg = *vacrelstats;
 	update_vacuum_error_cbarg(vacrelstats, VACUUM_ERRCB_PHASE_VACUUM_HEAP,
-							  blkno, NULL);
+							  blkno, NULL, false);
 
 	START_CRIT_SECTION();
 
@@ -1983,9 +1982,10 @@ lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
 
 	/* Clear the error traceback phase */
 	update_vacuum_error_cbarg(vacrelstats,
-							  VACUUM_ERRCB_PHASE_UNKNOWN, InvalidBlockNumber,
-							  NULL);
-
+							  olderrcbarg.phase,
+							  olderrcbarg.blkno,
+							  olderrcbarg.indname,
+							  true);
 	return tupindex;
 }
 
@@ -2383,6 +2383,7 @@ lazy_vacuum_index(Relation indrel, IndexBulkDeleteResult **stats,
 	IndexVacuumInfo ivinfo;
 	const char *msg;
 	PGRUsage	ru0;
+	LVRelStats	olderrcbarg;
 
 	pg_rusage_init(&ru0);
 
@@ -2395,9 +2396,12 @@ lazy_vacuum_index(Relation indrel, IndexBulkDeleteResult **stats,
 	ivinfo.strategy = vac_strategy;
 
 	/* Setup error traceback support for ereport() */
+	olderrcbarg = *vacrelstats;
 	update_vacuum_error_cbarg(vacrelstats,
-							  VACUUM_ERRCB_PHASE_VACUUM_INDEX, InvalidBlockNumber,
-							  RelationGetRelationName(indrel));
+							  VACUUM_ERRCB_PHASE_VACUUM_INDEX,
+							  InvalidBlockNumber,
+							  RelationGetRelationName(indrel),
+							  false);
 
 	/* Do bulk deletion */
 	*stats = index_bulk_delete(&ivinfo, *stats,
@@ -2416,8 +2420,10 @@ lazy_vacuum_index(Relation indrel, IndexBulkDeleteResult **stats,
 
 	/* Clear the error traceback phase */
 	update_vacuum_error_cbarg(vacrelstats,
-							  VACUUM_ERRCB_PHASE_UNKNOWN, InvalidBlockNumber,
-							  NULL);
+							  olderrcbarg.phase,
+							  olderrcbarg.blkno,
+							  olderrcbarg.indname,
+							  true);
 }
 
 /*
@@ -2434,6 +2440,7 @@ lazy_cleanup_index(Relation indrel,
 	IndexVacuumInfo ivinfo;
 	const char *msg;
 	PGRUsage	ru0;
+	LVRelStats	olderrcbarg;
 
 	pg_rusage_init(&ru0);
 
@@ -2447,10 +2454,12 @@ lazy_cleanup_index(Relation indrel,
 	ivinfo.strategy = vac_strategy;
 
 	/* Setup error traceback support for ereport() */
+	olderrcbarg = *vacrelstats;
 	update_vacuum_error_cbarg(vacrelstats,
 							  VACUUM_ERRCB_PHASE_INDEX_CLEANUP,
 							  InvalidBlockNumber,
-							  RelationGetRelationName(indrel));
+							  RelationGetRelationName(indrel),
+							  false);
 
 	*stats = index_vacuum_cleanup(&ivinfo, *stats);
 
@@ -2476,8 +2485,10 @@ lazy_cleanup_index(Relation indrel,
 
 	/* Clear the error traceback phase */
 	update_vacuum_error_cbarg(vacrelstats,
-							  VACUUM_ERRCB_PHASE_UNKNOWN, InvalidBlockNumber,
-							  NULL);
+							  olderrcbarg.phase,
+							  olderrcbarg.blkno,
+							  olderrcbarg.indname,
+							  true);
 }
 
 /*
@@ -3520,16 +3531,23 @@ vacuum_error_callback(void *arg)
 	}
 }
 
-/* Update vacuum error callback for current phase, block and index */
+/*
+ * Update vacuum error callback for current phase, block and index
+ *
+ * free_oldindex is true if the previous "indname" should be freed.  It must be
+ * false if the caller has copied the old LVRelSTats, to avoid keeping a
+ * pointer to a freed allocation.  In which case, the caller should call again
+ * with free_oldindname=true to avoid a leak.
+ */
 static void
 update_vacuum_error_cbarg(LVRelStats *errcbarg, int phase, BlockNumber blkno,
-						  char *indname)
+						  char *indname, bool free_oldindname)
 {
 	errcbarg->blkno = blkno;
 	errcbarg->phase = phase;
 
 	/* Free index name from any previous phase */
-	if (errcbarg->indname)
+	if (free_oldindname && errcbarg->indname)
 		pfree(errcbarg->indname);
 
 	/* For index phases, save the name of the current index for the callback */
-- 
2.17.0

--rG8Oha4Ryswg1dZ8
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Content-Disposition: attachment; filename="v28-0003-Drop-reltuples.patch"