From a6370fd9ed3dbad6070b789eae916d6a037e4773 Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Thu, 6 Jun 2013 10:03:37 -0400 Subject: [PATCH] Ensure that XLOG_HEAP2_VISIBLE always targets an initialized page. Andres Freund --- src/backend/commands/vacuumlazy.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c index 7e46f9e934..078b822059 100644 --- a/src/backend/commands/vacuumlazy.c +++ b/src/backend/commands/vacuumlazy.c @@ -663,6 +663,24 @@ lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats, /* empty pages are always all-visible */ if (!PageIsAllVisible(page)) { + /* + * It's possible that another backend has extended the heap, + * initialized the page, and then failed to WAL-log the page + * due to an ERROR. Since heap extension is not WAL-logged, + * recovery might try to replay our record setting the + * page all-visible and find that the page isn't initialized, + * which will cause a PANIC. To prevent that, check whether + * the page has been previously WAL-logged, and if not, do that + * now. + * + * XXX: It would be nice to use a logging method supporting + * standard buffers here since log_newpage_buffer() will write + * the full block instead of omitting the hole. + */ + if (RelationNeedsWAL(onerel) && + PageGetLSN(page) == InvalidXLogRecPtr) + log_newpage_buffer(buf); + PageSetAllVisible(page); MarkBufferDirty(buf); visibilitymap_set(onerel, blkno, buf, InvalidXLogRecPtr, -- 2.40.0