Count locked pages that don't need vacuuming as scanned.

Previously, if VACUUM skipped vacuuming a page because it's pinned, it
didn't count that page as scanned. However, that meant that relfrozenxid
was not bumped up either, which prevented anti-wraparound vacuum from
doing its job.

Report by Миша Тюрин, analysis and patch by Sergey Burladyn and Jeff Janes.
Backpatch to 9.2, where the skip-locked-pages behavior was introduced.

diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c
index c2b3d719b9392c52366e33cee612a13bda1a84aa..11d0192931f7e88a332fff6b1346f652ac7d1935 100644 (file)
--- a/src/backend/commands/vacuumlazy.c
+++ b/src/backend/commands/vacuumlazy.c
@@ -602,6 +602,7 @@ lazy_scan_heap(Relation onerel, LVRelStats *vacrelstats,
                        if (!lazy_check_needs_freeze(buf))
                        {
                                UnlockReleaseBuffer(buf);
+                               vacrelstats->scanned_pages++;
                                continue;
                        }
                        LockBuffer(buf, BUFFER_LOCK_UNLOCK);