From f6590f6a8e51ec9c81fd27cc0c900282bd57487b Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas 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 | 7 ++++++- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/src/backend/access/gin/ginfast.c b/src/backend/access/gin/ginfast.c index 4f2c11810a4..177a2246bc5 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 dbfbec73e57..f487ba5c1ad 100644 --- a/src/backend/access/gin/ginxlog.c +++ b/src/backend/access/gin/ginxlog.c @@ -606,7 +606,11 @@ 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 we have a full-page image, restore it and we're done. (As the code + * stands, we never create full-page images, but we used to. Cope if + * we're reading WAL generated with an older minor version.) + */ if (record->xl_info & XLR_BKP_BLOCK(0)) { (void) RestoreBackupBlock(lsn, record, 0, false, false); @@ -640,6 +644,7 @@ ginRedoInsertListPage(XLogRecPtr lsn, XLogRecord *record) elog(ERROR, "failed to add item to index page"); tuples = (IndexTuple) (((char *) tuples) + tupsize); + off++; } PageSetLSN(page, lsn);