From d2722443d993988ff2e529b652c61fec1ca527f7 Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Mon, 28 Apr 2014 16:12:45 +0300
Subject: [PATCH] Fix two bugs in WAL-logging of GIN pending-list pages.
In writeListPage, never take a full-page image of the page, because we
have all the information required to re-initialize in the WAL record
anyway. Before this fix, a full-page image was always generated, unless
full_page_writes=off, because when the page is initialized its LSN is
always 0. In stable-branches, keep the code to restore the backup blocks
if they exist, in case that the WAL is generated with an older minor
version, but in master Assert that there are no full-page images.
In the redo routine, add missing "off++". Otherwise the tuples are added
to the page in reverse order. That happens to be harmless because we
always scan and remove all the tuples together, but it was clearly wrong.
Also, it was masked by the first bug unless full_page_writes=off, because
the page was always restored from a full-page image.
Backpatch to all supported versions.
---
src/backend/access/gin/ginfast.c | 3 +--
src/backend/access/gin/ginxlog.c | 11 +++++------
2 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/src/backend/access/gin/ginfast.c b/src/backend/access/gin/ginfast.c
index 4a65046547e..a16c2140c22 100644
--- a/src/backend/access/gin/ginfast.c
+++ b/src/backend/access/gin/ginfast.c
@@ -119,8 +119,7 @@ writeListPage(Relation index, Buffer buffer,
rdata[0].len = sizeof(ginxlogInsertListPage);
rdata[0].next = rdata + 1;
- rdata[1].buffer = buffer;
- rdata[1].buffer_std = true;
+ rdata[1].buffer = InvalidBuffer;
rdata[1].data = workspace;
rdata[1].len = size;
rdata[1].next = NULL;
diff --git a/src/backend/access/gin/ginxlog.c b/src/backend/access/gin/ginxlog.c
index 4bb59d4312e..d19389330c5 100644
--- a/src/backend/access/gin/ginxlog.c
+++ b/src/backend/access/gin/ginxlog.c
@@ -814,12 +814,10 @@ ginRedoInsertListPage(XLogRecPtr lsn, XLogRecord *record)
tupsize;
IndexTuple tuples = (IndexTuple) (XLogRecGetData(record) + sizeof(ginxlogInsertListPage));
- /* If we have a full-page image, restore it and we're done */
- if (record->xl_info & XLR_BKP_BLOCK(0))
- {
- (void) RestoreBackupBlock(lsn, record, 0, false, false);
- return;
- }
+ /*
+ * Backup blocks are not used, we always re-initialize the page.
+ */
+ Assert(!(record->xl_info & XLR_BKP_BLOCK_MASK));
buffer = XLogReadBuffer(data->node, data->blkno, true);
Assert(BufferIsValid(buffer));
@@ -848,6 +846,7 @@ ginRedoInsertListPage(XLogRecPtr lsn, XLogRecord *record)
elog(ERROR, "failed to add item to index page");
tuples = (IndexTuple) (((char *) tuples) + tupsize);
+ off++;
}
PageSetLSN(page, lsn);
--
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