From a590f266e44c492d2a252ab9dee0cd88dbe06dc5 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Mon, 10 Nov 2014 18:13:49 -0300 Subject: [PATCH] BRIN: fix bug in xlog backup block counting The code that generates the BRIN_XLOG_UPDATE removes the buffer reference when the page that's target for the updated tuple is freshly initialized. This is a pretty usual optimization, but was breaking the case where the revmap buffer, which is referenced in the same WAL record, is getting a backup block: the replay code was using backup block index 1, which is not valid when the update target buffer gets pruned; the revmap buffer gets assigned 0 instead. Make sure to use the correct backup block index for revmap when replaying. Bug reported by Fujii Masao. --- src/backend/access/brin/brin_xlog.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/src/backend/access/brin/brin_xlog.c b/src/backend/access/brin/brin_xlog.c index ebef984e7f..29370689a7 100644 --- a/src/backend/access/brin/brin_xlog.c +++ b/src/backend/access/brin/brin_xlog.c @@ -60,9 +60,11 @@ brin_xlog_insert_update(XLogRecPtr lsn, XLogRecord *record, */ if (record->xl_info & XLOG_BRIN_INIT_PAGE) { - XLogReadBufferForRedoExtended(lsn, record, 0, - xlrec->node, MAIN_FORKNUM, blkno, - RBM_ZERO, false, &buffer); + /* + * No full-page image here. Don't try to read it, because there + * might be one for the revmap buffer, below. + */ + buffer = XLogReadBuffer(xlrec->node, blkno, true); page = BufferGetPage(buffer); brin_page_init(page, BRIN_PAGETYPE_REGULAR); action = BLK_NEEDS_REDO; @@ -97,7 +99,9 @@ brin_xlog_insert_update(XLogRecPtr lsn, XLogRecord *record, UnlockReleaseBuffer(buffer); /* update the revmap */ - action = XLogReadBufferForRedo(lsn, record, 1, xlrec->node, + action = XLogReadBufferForRedo(lsn, record, + record->xl_info & XLOG_BRIN_INIT_PAGE ? 0 : 1, + xlrec->node, xlrec->revmapBlk, &buffer); if (action == BLK_NEEDS_REDO) { -- 2.40.0