Hello.
While I looked into a patch, I noticed that check_tuple_attribute does
not run the check for compessed data even if a compressed data is
given.
check_tuple_attribute()
..
struct varatt_external toast_pointer;
..
VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
..
if (VARATT_IS_COMPRESSED(&toast_pointer))
{
Since toast_pointer is a varatt_exteral it should be
VARATT_EXTERNAL_IS_COMPRESSED instead. Since the just following
corss-check is just the reverse of what the macro does, it is useless.
What do you think about the attached? The problem code is new in
PG15.
regards.
--
Kyotaro Horiguchi
NTT Open Source Software Center
>From 00ae35ca30a6d3168dc4905ab5ba9db1339fe377 Mon Sep 17 00:00:00 2001
From: Kyotaro Horiguchi <horikyota....@gmail.com>
Date: Tue, 17 May 2022 16:19:27 +0900
Subject: [PATCH] Use correct macro to check compressed-ness in amcheck
check_tuple_attribute uses VARATT_IS_COMPRESSED() for
varatt_external. This should be VARATT_EXTERNAL_IS_COMPRESSED()
instead. Remove the following cross check for data size since the
ycondition cannot be true.
---
contrib/amcheck/verify_heapam.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)
diff --git a/contrib/amcheck/verify_heapam.c b/contrib/amcheck/verify_heapam.c
index c875f3e5a2..e488f5e234 100644
--- a/contrib/amcheck/verify_heapam.c
+++ b/contrib/amcheck/verify_heapam.c
@@ -1385,19 +1385,11 @@ check_tuple_attribute(HeapCheckContext *ctx)
toast_pointer.va_rawsize,
VARLENA_SIZE_LIMIT));
- if (VARATT_IS_COMPRESSED(&toast_pointer))
+ if (VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer))
{
ToastCompressionId cmid;
bool valid = false;
- /* Compression should never expand the attribute */
- if (VARATT_EXTERNAL_GET_EXTSIZE(toast_pointer) > toast_pointer.va_rawsize - VARHDRSZ)
- report_corruption(ctx,
- psprintf("toast value %u external size %u exceeds maximum expected for rawsize %d",
- toast_pointer.va_valueid,
- VARATT_EXTERNAL_GET_EXTSIZE(toast_pointer),
- toast_pointer.va_rawsize));
-
/* Compressed attributes should have a valid compression method */
cmid = TOAST_COMPRESS_METHOD(&toast_pointer);
switch (cmid)
--
2.27.0
