From 4873c96ff3f38b51b29c86ede658343be01f519f Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 14 Mar 2008 23:49:28 +0000
Subject: [PATCH] Fix inappropriately-timed memory context switch in
autovacuum_do_vac_analyze. This accidentally failed to fail before 8.3,
because the context we were switching back to was long-lived anyway; but it
sure looks risky as can be now. Well spotted by Pavan Deolasee.
---
src/backend/postmaster/autovacuum.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index ca0bdde7364..b55214e0bc5 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -55,7 +55,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.73 2008/03/14 17:25:58 alvherre Exp $
+ * $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.74 2008/03/14 23:49:28 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -2602,17 +2602,12 @@ autovacuum_do_vac_analyze(Oid relid, bool dovacuum, bool doanalyze,
BufferAccessStrategy bstrategy)
{
VacuumStmt vacstmt;
+ List *relids;
MemoryContext old_cxt;
+ /* Set up command parameters --- use a local variable instead of palloc */
MemSet(&vacstmt, 0, sizeof(vacstmt));
- /*
- * The list must survive transaction boundaries, so make sure we create it
- * in a long-lived context
- */
- old_cxt = MemoryContextSwitchTo(AutovacMemCxt);
-
- /* Set up command parameters */
vacstmt.type = T_VacuumStmt;
vacstmt.vacuum = dovacuum;
vacstmt.full = false;
@@ -2622,11 +2617,18 @@ autovacuum_do_vac_analyze(Oid relid, bool dovacuum, bool doanalyze,
vacstmt.relation = NULL; /* not used since we pass a relids list */
vacstmt.va_cols = NIL;
+ /*
+ * The list must survive transaction boundaries, so make sure we create it
+ * in a long-lived context
+ */
+ old_cxt = MemoryContextSwitchTo(AutovacMemCxt);
+ relids = list_make1_oid(relid);
+ MemoryContextSwitchTo(old_cxt);
+
/* Let pgstat know what we're doing */
autovac_report_activity(&vacstmt, relid);
- vacuum(&vacstmt, list_make1_oid(relid), bstrategy, for_wraparound, true);
- MemoryContextSwitchTo(old_cxt);
+ vacuum(&vacstmt, relids, bstrategy, for_wraparound, true);
}
/*
--
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