5 files changed, 24 insertions, 14 deletions
diff --git a/src/backend/access/gin/README b/src/backend/access/gin/README
index fade0cbb617..d551df1166c 100644
--- a/src/backend/access/gin/README
+++ b/src/backend/access/gin/README
@@ -304,12 +304,10 @@ the lock on next page has been acquired.
 The downlink is more tricky. A search descending the tree must release the
 lock on the parent page before locking the child, or it could deadlock with
 a concurrent split of the child page; a page split locks the parent, while
-already holding a lock on the child page. However, posting trees are only
-fully searched from left to right, starting from the leftmost leaf. (The
-tree-structure is only needed by insertions, to quickly find the correct
-insert location). So as long as we don't delete the leftmost page on each
-level, a search can never follow a downlink to page that's about to be
-deleted.
+already holding a lock on the child page. So, deleted page cannot be reclaimed
+immediately. Instead, we have to wait for every transaction, which might wait
+to reference this page, to finish. Corresponding processes must observe that
+the page is marked deleted and recover accordingly.
 
 The previous paragraph's reasoning only applies to searches, and only to
 posting trees. To protect from inserters following a downlink to a deleted
diff --git a/src/backend/access/gin/ginutil.c b/src/backend/access/gin/ginutil.c
index cb4e32fe66b..7fd1a4db4ce 100644
--- a/src/backend/access/gin/ginutil.c
+++ b/src/backend/access/gin/ginutil.c
@@ -228,12 +228,7 @@ GinNewBuffer(Relation index)
 		 */
 		if (ConditionalLockBuffer(buffer))
 		{
-			Page		page = BufferGetPage(buffer);
-
-			if (PageIsNew(page))
-				return buffer;	/* OK to use, if never initialized */
-
-			if (GinPageIsDeleted(page))
+			if (GinPageIsRecyclable(BufferGetPage(buffer)))
 				return buffer;	/* OK to use */
 
 			LockBuffer(buffer, GIN_UNLOCK);
diff --git a/src/backend/access/gin/ginvacuum.c b/src/backend/access/gin/ginvacuum.c
index 1315762ecf9..bc10d7b6623 100644
--- a/src/backend/access/gin/ginvacuum.c
+++ b/src/backend/access/gin/ginvacuum.c
@@ -215,6 +215,9 @@ ginDeletePage(GinVacuumState *gvs, BlockNumber deleteBlkno, BlockNumber leftBlkn
 	page = BufferGetPage(dBuffer);
 	rightlink = GinPageGetOpaque(page)->rightlink;
 
+	/* For deleted page remember last xid which could knew its address */
+	GinPageSetDeleteXid(page, ReadNewTransactionId());
+
 	page = BufferGetPage(lBuffer);
 	GinPageGetOpaque(page)->rightlink = rightlink;
 
@@ -262,6 +265,7 @@ ginDeletePage(GinVacuumState *gvs, BlockNumber deleteBlkno, BlockNumber leftBlkn
 
 		data.parentOffset = myoff;
 		data.rightLink = GinPageGetOpaque(page)->rightlink;
+		data.deleteXid = GinPageGetDeleteXid(page);
 
 		XLogRegisterData((char *) &data, sizeof(ginxlogDeletePage));
 
@@ -710,7 +714,7 @@ ginvacuumcleanup(PG_FUNCTION_ARGS)
 		LockBuffer(buffer, GIN_SHARE);
 		page = (Page) BufferGetPage(buffer);
 
-		if (PageIsNew(page) || GinPageIsDeleted(page))
+		if (GinPageIsRecyclable(page))
 		{
 			Assert(blkno != GIN_ROOT_BLKNO);
 			RecordFreeIndexPage(index, blkno);
diff --git a/src/backend/access/gin/ginxlog.c b/src/backend/access/gin/ginxlog.c
index 53b165326c5..e80daf31a9c 100644
--- a/src/backend/access/gin/ginxlog.c
+++ b/src/backend/access/gin/ginxlog.c
@@ -529,6 +529,7 @@ ginRedoDeletePage(XLogReaderState *record)
 		page = BufferGetPage(dbuffer);
 		Assert(GinPageIsData(page));
 		GinPageGetOpaque(page)->flags = GIN_DELETED;
+		GinPageSetDeleteXid(page, data->deleteXid);
 		PageSetLSN(page, lsn);
 		MarkBufferDirty(dbuffer);
 	}
diff --git a/src/include/access/gin_private.h b/src/include/access/gin_private.h
index fce9e221607..4ff7c3755c7 100644
--- a/src/include/access/gin_private.h
+++ b/src/include/access/gin_private.h
@@ -13,9 +13,11 @@
 #include "access/genam.h"
 #include "access/gin.h"
 #include "access/itup.h"
+#include "access/transam.h"
 #include "fmgr.h"
-#include "storage/bufmgr.h"
 #include "lib/rbtree.h"
+#include "storage/bufmgr.h"
+#include "utils/snapmgr.h"
 
 
 /*
@@ -132,6 +134,15 @@ typedef struct GinMetaPageData
 #define GinPageRightMost(page) ( GinPageGetOpaque(page)->rightlink == InvalidBlockNumber)
 
 /*
+ * We should reclaim deleted page only once every transaction started before
+ * its deletion is over.
+ */
+#define GinPageGetDeleteXid(page) ( ((PageHeader) (page))->pd_prune_xid )
+#define GinPageSetDeleteXid(page, xid) ( ((PageHeader) (page))->pd_prune_xid = xid)
+#define GinPageIsRecyclable(page) ( PageIsNew(page) || (GinPageIsDeleted(page) \
+	&& TransactionIdPrecedes(GinPageGetDeleteXid(page), RecentGlobalXmin)))
+
+/*
  * We use our own ItemPointerGet(BlockNumber|OffsetNumber)
  * to avoid Asserts, since sometimes the ip_posid isn't "valid"
  */
@@ -540,6 +551,7 @@ typedef struct ginxlogDeletePage
 {
 	OffsetNumber parentOffset;
 	BlockNumber rightLink;
+	TransactionId deleteXid;	/* last Xid which could see this page in scan */
 } ginxlogDeletePage;
 
 #define XLOG_GIN_UPDATE_META_PAGE 0x60