From 2076db2aea766c4c828dccc34ae35f614129000d Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Thu, 6 Nov 2014 13:52:08 +0200
Subject: [PATCH] Move the backup-block logic from XLogInsert to a new file,
 xloginsert.c.

xlog.c is huge, this makes it a little bit smaller, which is nice. Functions
related to putting together the WAL record are in xloginsert.c, and the
lower level stuff for managing WAL buffers and such are in xlog.c.

Also move the definition of XLogRecord to a separate header file. This
causes churn in the #includes of all the files that write WAL records, and
redo routines, but it avoids pulling in xlog.h into most places.

Reviewed by Michael Paquier, Alvaro Herrera, Andres Freund and Amit Kapila.
---
 contrib/pg_xlogdump/pg_xlogdump.c       |   2 +-
 doc/src/sgml/wal.sgml                   |  14 +-
 src/backend/access/gin/ginbtree.c       |   1 +
 src/backend/access/gin/gindatapage.c    |   1 +
 src/backend/access/gin/ginentrypage.c   |   1 +
 src/backend/access/gin/ginfast.c        |   1 +
 src/backend/access/gin/gininsert.c      |   1 +
 src/backend/access/gin/ginutil.c        |   1 +
 src/backend/access/gin/ginvacuum.c      |   1 +
 src/backend/access/gist/gistbuild.c     |   1 +
 src/backend/access/gist/gistxlog.c      |   1 +
 src/backend/access/heap/heapam.c        |   2 +
 src/backend/access/heap/pruneheap.c     |   1 +
 src/backend/access/heap/rewriteheap.c   |   1 +
 src/backend/access/heap/visibilitymap.c |   1 +
 src/backend/access/nbtree/nbtinsert.c   |   1 +
 src/backend/access/nbtree/nbtpage.c     |   2 +
 src/backend/access/nbtree/nbtree.c      |   1 +
 src/backend/access/nbtree/nbtsort.c     |   2 +
 src/backend/access/nbtree/nbtxlog.c     |   2 +
 src/backend/access/spgist/spgdoinsert.c |   1 +
 src/backend/access/spgist/spginsert.c   |   2 +
 src/backend/access/spgist/spgvacuum.c   |   1 +
 src/backend/access/spgist/spgxlog.c     |   1 +
 src/backend/access/transam/Makefile     |   2 +-
 src/backend/access/transam/clog.c       |   3 +
 src/backend/access/transam/multixact.c  |   2 +
 src/backend/access/transam/twophase.c   |   1 +
 src/backend/access/transam/varsup.c     |   1 +
 src/backend/access/transam/xact.c       |   2 +
 src/backend/access/transam/xlog.c       | 759 +++---------------------
 src/backend/access/transam/xloginsert.c | 633 ++++++++++++++++++++
 src/backend/access/transam/xlogreader.c |   2 +-
 src/backend/access/transam/xlogutils.c  | 121 ++++
 src/backend/catalog/heap.c              |   1 +
 src/backend/catalog/namespace.c         |   1 +
 src/backend/catalog/storage.c           |   2 +
 src/backend/commands/cluster.c          |   1 +
 src/backend/commands/copy.c             |   1 +
 src/backend/commands/createas.c         |   1 +
 src/backend/commands/dbcommands.c       |   1 +
 src/backend/commands/matview.c          |   1 +
 src/backend/commands/sequence.c         |   2 +
 src/backend/commands/tablecmds.c        |   1 +
 src/backend/commands/tablespace.c       |   2 +
 src/backend/commands/vacuumlazy.c       |   1 +
 src/backend/commands/variable.c         |   1 +
 src/backend/storage/buffer/bufmgr.c     |   1 +
 src/backend/storage/file/fd.c           |   1 +
 src/backend/storage/ipc/procarray.c     |   3 +-
 src/backend/storage/ipc/standby.c       |   1 +
 src/backend/storage/lmgr/lock.c         |   1 +
 src/backend/storage/lmgr/predicate.c    |   1 +
 src/backend/tcop/utility.c              |   1 +
 src/backend/utils/adt/txid.c            |   1 +
 src/backend/utils/cache/relcache.c      |   1 +
 src/backend/utils/cache/relmapper.c     |   2 +
 src/backend/utils/init/postinit.c       |   1 +
 src/backend/utils/sort/tuplestore.c     |   2 +
 src/backend/utils/time/tqual.c          |   1 +
 src/bin/pg_resetxlog/pg_resetxlog.c     |   1 +
 src/include/access/clog.h               |   3 +-
 src/include/access/gin.h                |   3 +-
 src/include/access/gin_private.h        |   1 +
 src/include/access/gist_private.h       |   1 +
 src/include/access/hash.h               |   3 +-
 src/include/access/heapam_xlog.h        |   4 +-
 src/include/access/multixact.h          |   3 +-
 src/include/access/nbtree.h             |   5 +-
 src/include/access/spgist.h             |   3 +-
 src/include/access/spgist_private.h     |   1 +
 src/include/access/xact.h               |   4 +-
 src/include/access/xlog.h               | 112 +---
 src/include/access/xlog_internal.h      |  38 +-
 src/include/access/xloginsert.h         |  66 +++
 src/include/access/xlogrecord.h         | 100 ++++
 src/include/access/xlogutils.h          |   8 +-
 src/include/catalog/storage_xlog.h      |   3 +-
 src/include/commands/dbcommands.h       |   3 +-
 src/include/commands/sequence.h         |   3 +-
 src/include/commands/tablespace.h       |   3 +-
 src/include/replication/decode.h        |   1 +
 src/include/storage/standby.h           |   3 +-
 src/include/utils/relmapper.h           |   3 +-
 84 files changed, 1122 insertions(+), 855 deletions(-)
 create mode 100644 src/backend/access/transam/xloginsert.c
 create mode 100644 src/include/access/xloginsert.h
 create mode 100644 src/include/access/xlogrecord.h

diff --git a/contrib/pg_xlogdump/pg_xlogdump.c b/contrib/pg_xlogdump/pg_xlogdump.c
index adc9087a1d..7f151f961c 100644
--- a/contrib/pg_xlogdump/pg_xlogdump.c
+++ b/contrib/pg_xlogdump/pg_xlogdump.c
@@ -15,8 +15,8 @@
 #include <dirent.h>
 #include <unistd.h>
 
-#include "access/xlog.h"
 #include "access/xlogreader.h"
+#include "access/xlogrecord.h"
 #include "access/transam.h"
 #include "common/fe_memutils.h"
 #include "getopt_long.h"
diff --git a/doc/src/sgml/wal.sgml b/doc/src/sgml/wal.sgml
index 0420610a01..6172a087f2 100644
--- a/doc/src/sgml/wal.sgml
+++ b/doc/src/sgml/wal.sgml
@@ -578,12 +578,12 @@
 
   <para>
    There are two commonly used internal <acronym>WAL</acronym> functions:
-   <function>XLogInsert</function> and <function>XLogFlush</function>.
-   <function>XLogInsert</function> is used to place a new record into
+   <function>XLogInsertRecord</function> and <function>XLogFlush</function>.
+   <function>XLogInsertRecord</function> is used to place a new record into
    the <acronym>WAL</acronym> buffers in shared memory. If there is no
-   space for the new record, <function>XLogInsert</function> will have
+   space for the new record, <function>XLogInsertRecord</function> will have
    to write (move to kernel cache) a few filled <acronym>WAL</acronym>
-   buffers. This is undesirable because <function>XLogInsert</function>
+   buffers. This is undesirable because <function>XLogInsertRecord</function>
    is used on every database low level modification (for example, row
    insertion) at a time when an exclusive lock is held on affected
    data pages, so the operation needs to be as fast as possible.  What
@@ -594,7 +594,7 @@
    made, for the most part, at transaction commit time to ensure that
    transaction records are flushed to permanent storage. On systems
    with high log output, <function>XLogFlush</function> requests might
-   not occur often enough to prevent <function>XLogInsert</function>
+   not occur often enough to prevent <function>XLogInsertRecord</function>
    from having to do writes.  On such systems
    one should increase the number of <acronym>WAL</acronym> buffers by
    modifying the <xref linkend="guc-wal-buffers"> parameter.  When
@@ -683,7 +683,7 @@
    Enabling the <xref linkend="guc-wal-debug"> configuration parameter
    (provided that <productname>PostgreSQL</productname> has been
    compiled with support for it) will result in each
-   <function>XLogInsert</function> and <function>XLogFlush</function>
+   <function>XLogInsertRecord</function> and <function>XLogFlush</function>
    <acronym>WAL</acronym> call being logged to the server log. This
    option might be replaced by a more general mechanism in the future.
   </para>
@@ -708,7 +708,7 @@
    building the server).  Each segment is divided into pages, normally
    8 kB each (this size can be changed via the <option>--with-wal-blocksize</>
    configure option).  The log record headers are described in
-   <filename>access/xlog.h</filename>; the record content is dependent
+   <filename>access/xlogrecord.h</filename>; the record content is dependent
    on the type of event that is being logged.  Segment files are given
    ever-increasing numbers as names, starting at
    <filename>000000010000000000000000</filename>.  The numbers do not wrap,
diff --git a/src/backend/access/gin/ginbtree.c b/src/backend/access/gin/ginbtree.c
index 27f88e0eb2..5365477000 100644
--- a/src/backend/access/gin/ginbtree.c
+++ b/src/backend/access/gin/ginbtree.c
@@ -15,6 +15,7 @@
 #include "postgres.h"
 
 #include "access/gin_private.h"
+#include "access/xloginsert.h"
 #include "miscadmin.h"
 #include "utils/rel.h"
 
diff --git a/src/backend/access/gin/gindatapage.c b/src/backend/access/gin/gindatapage.c
index e2d15a85fe..97cd706c08 100644
--- a/src/backend/access/gin/gindatapage.c
+++ b/src/backend/access/gin/gindatapage.c
@@ -15,6 +15,7 @@
 #include "postgres.h"
 
 #include "access/gin_private.h"
+#include "access/xloginsert.h"
 #include "lib/ilist.h"
 #include "miscadmin.h"
 #include "utils/memutils.h"
diff --git a/src/backend/access/gin/ginentrypage.c b/src/backend/access/gin/ginentrypage.c
index 412f90da4d..84dc1e228c 100644
--- a/src/backend/access/gin/ginentrypage.c
+++ b/src/backend/access/gin/ginentrypage.c
@@ -15,6 +15,7 @@
 #include "postgres.h"
 
 #include "access/gin_private.h"
+#include "access/xloginsert.h"
 #include "miscadmin.h"
 #include "utils/rel.h"
 
diff --git a/src/backend/access/gin/ginfast.c b/src/backend/access/gin/ginfast.c
index 09c3e39bf3..ed581977f5 100644
--- a/src/backend/access/gin/ginfast.c
+++ b/src/backend/access/gin/ginfast.c
@@ -19,6 +19,7 @@
 #include "postgres.h"
 
 #include "access/gin_private.h"
+#include "access/xloginsert.h"
 #include "commands/vacuum.h"
 #include "miscadmin.h"
 #include "utils/memutils.h"
diff --git a/src/backend/access/gin/gininsert.c b/src/backend/access/gin/gininsert.c
index 2fbd1bf5e4..370884ed17 100644
--- a/src/backend/access/gin/gininsert.c
+++ b/src/backend/access/gin/gininsert.c
@@ -15,6 +15,7 @@
 #include "postgres.h"
 
 #include "access/gin_private.h"
+#include "access/xloginsert.h"
 #include "catalog/index.h"
 #include "miscadmin.h"
 #include "storage/bufmgr.h"
diff --git a/src/backend/access/gin/ginutil.c b/src/backend/access/gin/ginutil.c
index 3ca0b68434..1f8db9de6d 100644
--- a/src/backend/access/gin/ginutil.c
+++ b/src/backend/access/gin/ginutil.c
@@ -16,6 +16,7 @@
 
 #include "access/gin_private.h"
 #include "access/reloptions.h"
+#include "access/xloginsert.h"
 #include "catalog/pg_collation.h"
 #include "catalog/pg_type.h"
 #include "miscadmin.h"
diff --git a/src/backend/access/gin/ginvacuum.c b/src/backend/access/gin/ginvacuum.c
index af4d2714b5..3a61321a83 100644
--- a/src/backend/access/gin/ginvacuum.c
+++ b/src/backend/access/gin/ginvacuum.c
@@ -15,6 +15,7 @@
 #include "postgres.h"
 
 #include "access/gin_private.h"
+#include "access/xloginsert.h"
 #include "commands/vacuum.h"
 #include "miscadmin.h"
 #include "postmaster/autovacuum.h"
diff --git a/src/backend/access/gist/gistbuild.c b/src/backend/access/gist/gistbuild.c
index 1832687aa0..2143096c66 100644
--- a/src/backend/access/gist/gistbuild.c
+++ b/src/backend/access/gist/gistbuild.c
@@ -18,6 +18,7 @@
 
 #include "access/genam.h"
 #include "access/gist_private.h"
+#include "access/xloginsert.h"
 #include "catalog/index.h"
 #include "miscadmin.h"
 #include "optimizer/cost.h"
diff --git a/src/backend/access/gist/gistxlog.c b/src/backend/access/gist/gistxlog.c
index ecc095671d..b732f53267 100644
--- a/src/backend/access/gist/gistxlog.c
+++ b/src/backend/access/gist/gistxlog.c
@@ -14,6 +14,7 @@
 #include "postgres.h"
 
 #include "access/gist_private.h"
+#include "access/xloginsert.h"
 #include "access/xlogutils.h"
 #include "utils/memutils.h"
 
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 808b942c5e..8f671ac434 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -51,6 +51,8 @@
 #include "access/valid.h"
 #include "access/visibilitymap.h"
 #include "access/xact.h"
+#include "access/xlog.h"
+#include "access/xloginsert.h"
 #include "access/xlogutils.h"
 #include "catalog/catalog.h"
 #include "catalog/namespace.h"
diff --git a/src/backend/access/heap/pruneheap.c b/src/backend/access/heap/pruneheap.c
index 06b5488923..e4561bc3a2 100644
--- a/src/backend/access/heap/pruneheap.c
+++ b/src/backend/access/heap/pruneheap.c
@@ -18,6 +18,7 @@
 #include "access/heapam_xlog.h"
 #include "access/transam.h"
 #include "access/htup_details.h"
+#include "access/xlog.h"
 #include "catalog/catalog.h"
 #include "miscadmin.h"
 #include "pgstat.h"
diff --git a/src/backend/access/heap/rewriteheap.c b/src/backend/access/heap/rewriteheap.c
index 951f3f1a48..bea52460a0 100644
--- a/src/backend/access/heap/rewriteheap.c
+++ b/src/backend/access/heap/rewriteheap.c
@@ -113,6 +113,7 @@
 #include "access/transam.h"
 #include "access/tuptoaster.h"
 #include "access/xact.h"
+#include "access/xloginsert.h"
 
 #include "catalog/catalog.h"
 
diff --git a/src/backend/access/heap/visibilitymap.c b/src/backend/access/heap/visibilitymap.c
index a0c0c7f2a6..350a52fc52 100644
--- a/src/backend/access/heap/visibilitymap.c
+++ b/src/backend/access/heap/visibilitymap.c
@@ -84,6 +84,7 @@
 
 #include "access/heapam_xlog.h"
 #include "access/visibilitymap.h"
+#include "access/xlog.h"
 #include "miscadmin.h"
 #include "storage/bufmgr.h"
 #include "storage/lmgr.h"
diff --git a/src/backend/access/nbtree/nbtinsert.c b/src/backend/access/nbtree/nbtinsert.c
index 59d7006c94..bcaba7e5e8 100644
--- a/src/backend/access/nbtree/nbtinsert.c
+++ b/src/backend/access/nbtree/nbtinsert.c
@@ -18,6 +18,7 @@
 #include "access/heapam.h"
 #include "access/nbtree.h"
 #include "access/transam.h"
+#include "access/xloginsert.h"
 #include "miscadmin.h"
 #include "storage/lmgr.h"
 #include "storage/predicate.h"
diff --git a/src/backend/access/nbtree/nbtpage.c b/src/backend/access/nbtree/nbtpage.c
index b71f65de2c..6093215c43 100644
--- a/src/backend/access/nbtree/nbtpage.c
+++ b/src/backend/access/nbtree/nbtpage.c
@@ -24,6 +24,8 @@
 
 #include "access/nbtree.h"
 #include "access/transam.h"
+#include "access/xlog.h"
+#include "access/xloginsert.h"
 #include "miscadmin.h"
 #include "storage/indexfsm.h"
 #include "storage/lmgr.h"
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c
index 117b18e590..d881525bd3 100644
--- a/src/backend/access/nbtree/nbtree.c
+++ b/src/backend/access/nbtree/nbtree.c
@@ -20,6 +20,7 @@
 
 #include "access/nbtree.h"
 #include "access/relscan.h"
+#include "access/xlog.h"
 #include "catalog/index.h"
 #include "commands/vacuum.h"
 #include "storage/indexfsm.h"
diff --git a/src/backend/access/nbtree/nbtsort.c b/src/backend/access/nbtree/nbtsort.c
index e8a89d24ae..31d48210b2 100644
--- a/src/backend/access/nbtree/nbtsort.c
+++ b/src/backend/access/nbtree/nbtsort.c
@@ -67,6 +67,8 @@
 #include "postgres.h"
 
 #include "access/nbtree.h"
+#include "access/xlog.h"
+#include "access/xloginsert.h"
 #include "miscadmin.h"
 #include "storage/smgr.h"
 #include "tcop/tcopprot.h"
diff --git a/src/backend/access/nbtree/nbtxlog.c b/src/backend/access/nbtree/nbtxlog.c
index fac006e297..13951be62a 100644
--- a/src/backend/access/nbtree/nbtxlog.c
+++ b/src/backend/access/nbtree/nbtxlog.c
@@ -17,6 +17,8 @@
 #include "access/heapam_xlog.h"
 #include "access/nbtree.h"
 #include "access/transam.h"
+#include "access/xlog.h"
+#include "access/xlogutils.h"
 #include "storage/procarray.h"
 #include "miscadmin.h"
 
diff --git a/src/backend/access/spgist/spgdoinsert.c b/src/backend/access/spgist/spgdoinsert.c
index bab93a5dd3..21a071ab19 100644
--- a/src/backend/access/spgist/spgdoinsert.c
+++ b/src/backend/access/spgist/spgdoinsert.c
@@ -16,6 +16,7 @@
 #include "postgres.h"
 
 #include "access/genam.h"
+#include "access/xloginsert.h"
 #include "access/spgist_private.h"
 #include "miscadmin.h"
 #include "storage/bufmgr.h"
diff --git a/src/backend/access/spgist/spginsert.c b/src/backend/access/spgist/spginsert.c
index 7c104f49cc..e1dfc8e358 100644
--- a/src/backend/access/spgist/spginsert.c
+++ b/src/backend/access/spgist/spginsert.c
@@ -18,6 +18,8 @@
 
 #include "access/genam.h"
 #include "access/spgist_private.h"
+#include "access/xlog.h"
+#include "access/xloginsert.h"
 #include "catalog/index.h"
 #include "miscadmin.h"
 #include "storage/bufmgr.h"
diff --git a/src/backend/access/spgist/spgvacuum.c b/src/backend/access/spgist/spgvacuum.c
index 01b8ffe5ac..a028cf1f42 100644
--- a/src/backend/access/spgist/spgvacuum.c
+++ b/src/backend/access/spgist/spgvacuum.c
@@ -18,6 +18,7 @@
 #include "access/genam.h"
 #include "access/spgist_private.h"
 #include "access/transam.h"
+#include "access/xloginsert.h"
 #include "catalog/storage_xlog.h"
 #include "commands/vacuum.h"
 #include "miscadmin.h"
diff --git a/src/backend/access/spgist/spgxlog.c b/src/backend/access/spgist/spgxlog.c
index 911a14828e..920739436a 100644
--- a/src/backend/access/spgist/spgxlog.c
+++ b/src/backend/access/spgist/spgxlog.c
@@ -16,6 +16,7 @@
 
 #include "access/spgist_private.h"
 #include "access/transam.h"
+#include "access/xlog.h"
 #include "access/xlogutils.h"
 #include "storage/standby.h"
 #include "utils/memutils.h"
diff --git a/src/backend/access/transam/Makefile b/src/backend/access/transam/Makefile
index eb6cfc5c44..82a6c7695f 100644
--- a/src/backend/access/transam/Makefile
+++ b/src/backend/access/transam/Makefile
@@ -14,7 +14,7 @@ include $(top_builddir)/src/Makefile.global
 
 OBJS = clog.o transam.o varsup.o xact.o rmgr.o slru.o subtrans.o multixact.o \
 	timeline.o twophase.o twophase_rmgr.o xlog.o xlogarchive.o xlogfuncs.o \
-	xlogreader.o xlogutils.o
+	xloginsert.o xlogreader.o xlogutils.o
 
 include $(top_srcdir)/src/backend/common.mk
 
diff --git a/src/backend/access/transam/clog.c b/src/backend/access/transam/clog.c
index 27ca4c6567..5ee070bd0a 100644
--- a/src/backend/access/transam/clog.c
+++ b/src/backend/access/transam/clog.c
@@ -35,6 +35,9 @@
 #include "access/clog.h"
 #include "access/slru.h"
 #include "access/transam.h"
+#include "access/xlog.h"
+#include "access/xloginsert.h"
+#include "access/xlogutils.h"
 #include "miscadmin.h"
 #include "pg_trace.h"
 
diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c
index 33346c7664..bfbe738530 100644
--- a/src/backend/access/transam/multixact.c
+++ b/src/backend/access/transam/multixact.c
@@ -72,6 +72,8 @@
 #include "access/twophase.h"
 #include "access/twophase_rmgr.h"
 #include "access/xact.h"
+#include "access/xlog.h"
+#include "access/xloginsert.h"
 #include "catalog/pg_type.h"
 #include "commands/dbcommands.h"
 #include "funcapi.h"
diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index c4069c39a2..d23c292edc 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -48,6 +48,7 @@
 #include "access/twophase_rmgr.h"
 #include "access/xact.h"
 #include "access/xlog.h"
+#include "access/xloginsert.h"
 #include "access/xlogutils.h"
 #include "catalog/pg_type.h"
 #include "catalog/storage.h"
diff --git a/src/backend/access/transam/varsup.c b/src/backend/access/transam/varsup.c
index 7013fb894b..d51cca406c 100644
--- a/src/backend/access/transam/varsup.c
+++ b/src/backend/access/transam/varsup.c
@@ -17,6 +17,7 @@
 #include "access/subtrans.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "commands/dbcommands.h"
 #include "miscadmin.h"
 #include "postmaster/autovacuum.h"
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 651a5c40f4..6f92bad07c 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -25,6 +25,8 @@
 #include "access/transam.h"
 #include "access/twophase.h"
 #include "access/xact.h"
+#include "access/xlog.h"
+#include "access/xloginsert.h"
 #include "access/xlogutils.h"
 #include "catalog/catalog.h"
 #include "catalog/namespace.h"
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 3160db7245..563d442a7a 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -31,6 +31,7 @@
 #include "access/twophase.h"
 #include "access/xact.h"
 #include "access/xlog_internal.h"
+#include "access/xloginsert.h"
 #include "access/xlogreader.h"
 #include "access/xlogutils.h"
 #include "catalog/catversion.h"
@@ -300,13 +301,20 @@ XLogRecPtr	XactLastRecEnd = InvalidXLogRecPtr;
  * (which is almost but not quite the same as a pointer to the most recent
  * CHECKPOINT record).  We update this from the shared-memory copy,
  * XLogCtl->Insert.RedoRecPtr, whenever we can safely do so (ie, when we
- * hold an insertion lock).  See XLogInsert for details.  We are also allowed
- * to update from XLogCtl->RedoRecPtr if we hold the info_lck;
+ * hold an insertion lock).  See XLogInsertRecord for details.  We are also
+ * allowed to update from XLogCtl->RedoRecPtr if we hold the info_lck;
  * see GetRedoRecPtr.  A freshly spawned backend obtains the value during
  * InitXLOGAccess.
  */
 static XLogRecPtr RedoRecPtr;
 
+/*
+ * doPageWrites is this backend's local copy of (forcePageWrites ||
+ * fullPageWrites).  It is used together with RedoRecPtr to decide whether
+ * a full-page image of a page need to be taken.
+ */
+static bool doPageWrites;
+
 /*
  * RedoStartLSN points to the checkpoint's REDO location which is specified
  * in a backup label file, backup history file or control file. In standby
@@ -419,7 +427,7 @@ typedef union WALInsertLockPadded
 } WALInsertLockPadded;
 
 /*
- * Shared state data for XLogInsert.
+ * Shared state data for WAL insertion.
  */
 typedef struct XLogCtlInsert
 {
@@ -765,10 +773,6 @@ static void CheckPointGuts(XLogRecPtr checkPointRedo, int flags);
 static void KeepLogSeg(XLogRecPtr recptr, XLogSegNo *logSegNo);
 static XLogRecPtr XLogGetReplicationSlotMinimumLSN(void);
 
-static bool XLogCheckBuffer(XLogRecData *rdata, bool holdsExclusiveLock,
-				XLogRecPtr *lsn, BkpBlock *bkpb);
-static Buffer RestoreBackupBlockContents(XLogRecPtr lsn, BkpBlock bkpb,
-						 char *blk, bool get_cleanup_lock, bool keep_buffer);
 static void AdvanceXLInsertBuffer(XLogRecPtr upto, bool opportunistic);
 static bool XLogCheckpointNeeded(XLogSegNo new_segno);
 static void XLogWrite(XLogwrtRqst WriteRqst, bool flexible);
@@ -831,226 +835,45 @@ static void WALInsertLockRelease(void);
 static void WALInsertLockUpdateInsertingAt(XLogRecPtr insertingAt);
 
 /*
- * Insert an XLOG record having the specified RMID and info bytes,
- * with the body of the record being the data chunk(s) described by
- * the rdata chain (see xlog.h for notes about rdata).
+ * Insert an XLOG record represented by an already-constructed chain of data
+ * chunks.  This is a low-level routine; to construct the WAL record header
+ * and data, use the higher-level routines in xloginsert.c.
+ *
+ * If 'fpw_lsn' is valid, it is the oldest LSN among the pages that this
+ * WAL record applies to, that were not included in the record as full page
+ * images.  If fpw_lsn >= RedoRecPtr, the function does not perform the
+ * insertion and returns InvalidXLogRecPtr.  The caller can then recalculate
+ * which pages need a full-page image, and retry.  If fpw_lsn is invalid, the
+ * record is always inserted.
+ *
+ * The first XLogRecData in the chain must be for the record header, and its
+ * data must be MAXALIGNed.  XLogInsertRecord fills in the xl_prev and
+ * xl_crc fields in the header, the rest of the header must already be filled
+ * by the caller.
  *
  * Returns XLOG pointer to end of record (beginning of next record).
  * This can be used as LSN for data pages affected by the logged action.
  * (LSN is the XLOG point up to which the XLOG must be flushed to disk
  * before the data page can be written out.  This implements the basic
  * WAL rule "write the log before the data".)
- *
- * NB: this routine feels free to scribble on the XLogRecData structs,
- * though not on the data they reference.  This is OK since the XLogRecData
- * structs are always just temporaries in the calling code.
  */
 XLogRecPtr
-XLogInsert(RmgrId rmid, uint8 info, XLogRecData *rdata)
+XLogInsertRecord(XLogRecData *rdata, XLogRecPtr fpw_lsn)
 {
 	XLogCtlInsert *Insert = &XLogCtl->Insert;
 	XLogRecData *rdt;
-	XLogRecData *rdt_lastnormal;
-	Buffer		dtbuf[XLR_MAX_BKP_BLOCKS];
-	bool		dtbuf_bkp[XLR_MAX_BKP_BLOCKS];
-	BkpBlock	dtbuf_xlg[XLR_MAX_BKP_BLOCKS];
-	XLogRecPtr	dtbuf_lsn[XLR_MAX_BKP_BLOCKS];
-	XLogRecData dtbuf_rdt1[XLR_MAX_BKP_BLOCKS];
-	XLogRecData dtbuf_rdt2[XLR_MAX_BKP_BLOCKS];
-	XLogRecData dtbuf_rdt3[XLR_MAX_BKP_BLOCKS];
-	XLogRecData hdr_rdt;
 	pg_crc32	rdata_crc;
-	uint32		len,
-				write_len;
-	unsigned	i;
-	bool		doPageWrites;
-	bool		isLogSwitch = (rmid == RM_XLOG_ID && info == XLOG_SWITCH);
 	bool		inserted;
-	uint8		info_orig = info;
-	static XLogRecord *rechdr;
+	XLogRecord *rechdr = (XLogRecord *) rdata->data;
+	bool		isLogSwitch = (rechdr->xl_rmid == RM_XLOG_ID &&
+							   rechdr->xl_info == XLOG_SWITCH);
 	XLogRecPtr	StartPos;
 	XLogRecPtr	EndPos;
 
-	if (rechdr == NULL)
-	{
-		static char rechdrbuf[SizeOfXLogRecord + MAXIMUM_ALIGNOF];
-
-		rechdr = (XLogRecord *) MAXALIGN(&rechdrbuf);
-		MemSet(rechdr, 0, SizeOfXLogRecord);
-	}
-
 	/* cross-check on whether we should be here or not */
 	if (!XLogInsertAllowed())
 		elog(ERROR, "cannot make new WAL entries during recovery");
 
-	/* info's high bits are reserved for use by me */
-	if (info & XLR_INFO_MASK)
-		elog(PANIC, "invalid xlog info mask %02X", info);
-
-	TRACE_POSTGRESQL_XLOG_INSERT(rmid, info);
-
-	/*
-	 * In bootstrap mode, we don't actually log anything but XLOG resources;
-	 * return a phony record pointer.
-	 */
-	if (IsBootstrapProcessingMode() && rmid != RM_XLOG_ID)
-	{
-		EndPos = SizeOfXLogLongPHD;		/* start of 1st chkpt record */
-		return EndPos;
-	}
-
-	/*
-	 * Here we scan the rdata chain, to determine which buffers must be backed
-	 * up.
-	 *
-	 * We may have to loop back to here if a race condition is detected below.
-	 * We could prevent the race by doing all this work while holding an
-	 * insertion lock, but it seems better to avoid doing CRC calculations
-	 * while holding one.
-	 *
-	 * We add entries for backup blocks to the chain, so that they don't need
-	 * any special treatment in the critical section where the chunks are
-	 * copied into the WAL buffers. Those entries have to be unlinked from the
-	 * chain if we have to loop back here.
-	 */
-begin:;
-	for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
-	{
-		dtbuf[i] = InvalidBuffer;
-		dtbuf_bkp[i] = false;
-	}
-
-	/*
-	 * Decide if we need to do full-page writes in this XLOG record: true if
-	 * full_page_writes is on or we have a PITR request for it.  Since we
-	 * don't yet have an insertion lock, fullPageWrites and forcePageWrites
-	 * could change under us, but we'll recheck them once we have a lock.
-	 */
-	doPageWrites = Insert->fullPageWrites || Insert->forcePageWrites;
-
-	len = 0;
-	for (rdt = rdata;;)
-	{
-		if (rdt->buffer == InvalidBuffer)
-		{
-			/* Simple data, just include it */
-			len += rdt->len;
-		}
-		else
-		{
-			/* Find info for buffer */
-			for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
-			{
-				if (rdt->buffer == dtbuf[i])
-				{
-					/* Buffer already referenced by earlier chain item */
-					if (dtbuf_bkp[i])
-					{
-						rdt->data = NULL;
-						rdt->len = 0;
-					}
-					else if (rdt->data)
-						len += rdt->len;
-					break;
-				}
-				if (dtbuf[i] == InvalidBuffer)
-				{
-					/* OK, put it in this slot */
-					dtbuf[i] = rdt->buffer;
-					if (doPageWrites && XLogCheckBuffer(rdt, true,
-										   &(dtbuf_lsn[i]), &(dtbuf_xlg[i])))
-					{
-						dtbuf_bkp[i] = true;
-						rdt->data = NULL;
-						rdt->len = 0;
-					}
-					else if (rdt->data)
-						len += rdt->len;
-					break;
-				}
-			}
-			if (i >= XLR_MAX_BKP_BLOCKS)
-				elog(PANIC, "can backup at most %d blocks per xlog record",
-					 XLR_MAX_BKP_BLOCKS);
-		}
-		/* Break out of loop when rdt points to last chain item */
-		if (rdt->next == NULL)
-			break;
-		rdt = rdt->next;
-	}
-
-	/*
-	 * NOTE: We disallow len == 0 because it provides a useful bit of extra
-	 * error checking in ReadRecord.  This means that all callers of
-	 * XLogInsert must supply at least some not-in-a-buffer data.  However, we
-	 * make an exception for XLOG SWITCH records because we don't want them to
-	 * ever cross a segment boundary.
-	 */
-	if (len == 0 && !isLogSwitch)
-		elog(PANIC, "invalid xlog record length %u", len);
-
-	/*
-	 * Make additional rdata chain entries for the backup blocks, so that we
-	 * don't need to special-case them in the write loop.  This modifies the
-	 * original rdata chain, but we keep a pointer to the last regular entry,
-	 * rdt_lastnormal, so that we can undo this if we have to loop back to the
-	 * beginning.
-	 *
-	 * At the exit of this loop, write_len includes the backup block data.
-	 *
-	 * Also set the appropriate info bits to show which buffers were backed
-	 * up. The XLR_BKP_BLOCK(N) bit corresponds to the N'th distinct buffer
-	 * value (ignoring InvalidBuffer) appearing in the rdata chain.
-	 */
-	rdt_lastnormal = rdt;
-	write_len = len;
-	for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
-	{
-		BkpBlock   *bkpb;
-		char	   *page;
-
-		if (!dtbuf_bkp[i])
-			continue;
-
-		info |= XLR_BKP_BLOCK(i);
-
-		bkpb = &(dtbuf_xlg[i]);
-		page = (char *) BufferGetBlock(dtbuf[i]);
-
-		rdt->next = &(dtbuf_rdt1[i]);
-		rdt = rdt->next;
-
-		rdt->data = (char *) bkpb;
-		rdt->len = sizeof(BkpBlock);
-		write_len += sizeof(BkpBlock);
-
-		rdt->next = &(dtbuf_rdt2[i]);
-		rdt = rdt->next;
-
-		if (bkpb->hole_length == 0)
-		{
-			rdt->data = page;
-			rdt->len = BLCKSZ;
-			write_len += BLCKSZ;
-			rdt->next = NULL;
-		}
-		else
-		{
-			/* must skip the hole */
-			rdt->data = page;
-			rdt->len = bkpb->hole_offset;
-			write_len += bkpb->hole_offset;
-
-			rdt->next = &(dtbuf_rdt3[i]);
-			rdt = rdt->next;
-
-			rdt->data = page + (bkpb->hole_offset + bkpb->hole_length);
-			rdt->len = BLCKSZ - (bkpb->hole_offset + bkpb->hole_length);
-			write_len += rdt->len;
-			rdt->next = NULL;
-		}
-	}
-
 	/*
 	 * Calculate CRC of the data, including all the backup blocks
 	 *
@@ -1060,29 +883,15 @@ begin:;
 	 * header.
 	 */
 	INIT_CRC32C(rdata_crc);
-	for (rdt = rdata; rdt != NULL; rdt = rdt->next)
+	for (rdt = rdata->next; rdt != NULL; rdt = rdt->next)
 		COMP_CRC32C(rdata_crc, rdt->data, rdt->len);
 
 	/*
-	 * Construct record header (prev-link is filled in later, after reserving
-	 * the space for the record), and make that the first chunk in the chain.
-	 *
-	 * The CRC calculated for the header here doesn't include prev-link,
-	 * because we don't know it yet. It will be added later.
+	 * Calculate CRC of the header, except for prev-link, because we don't
+	 * know it yet.  It will be added later.
 	 */
-	rechdr->xl_xid = GetCurrentTransactionIdIfAny();
-	rechdr->xl_tot_len = SizeOfXLogRecord + write_len;
-	rechdr->xl_len = len;		/* doesn't include backup blocks */
-	rechdr->xl_info = info;
-	rechdr->xl_rmid = rmid;
-	rechdr->xl_prev = InvalidXLogRecPtr;
 	COMP_CRC32C(rdata_crc, ((char *) rechdr), offsetof(XLogRecord, xl_prev));
 
-	hdr_rdt.next = rdata;
-	hdr_rdt.data = (char *) rechdr;
-	hdr_rdt.len = SizeOfXLogRecord;
-	write_len += SizeOfXLogRecord;
-
 	/*----------
 	 *
 	 * We have now done all the preparatory work we can without holding a
@@ -1122,56 +931,33 @@ begin:;
 		WALInsertLockAcquire();
 
 	/*
-	 * Check to see if my RedoRecPtr is out of date.  If so, may have to go
-	 * back and recompute everything.  This can only happen just after a
-	 * checkpoint, so it's better to be slow in this case and fast otherwise.
+	 * Check to see if my copy of RedoRecPtr or doPageWrites is out of date.
+	 * If so, may have to go back and have the caller recompute everything.
+	 * This can only happen just after a checkpoint, so it's better to be
+	 * slow in this case and fast otherwise.
 	 *
 	 * If we aren't doing full-page writes then RedoRecPtr doesn't actually
 	 * affect the contents of the XLOG record, so we'll update our local copy
-	 * but not force a recomputation.
+	 * but not force a recomputation.  (If doPageWrites was just turned off,
+	 * we could recompute the record without full pages, but we choose not
+	 * to bother.)
 	 */
 	if (RedoRecPtr != Insert->RedoRecPtr)
 	{
 		Assert(RedoRecPtr < Insert->RedoRecPtr);
 		RedoRecPtr = Insert->RedoRecPtr;
-
-		if (doPageWrites)
-		{
-			for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
-			{
-				if (dtbuf[i] == InvalidBuffer)
-					continue;
-				if (dtbuf_bkp[i] == false &&
-					dtbuf_lsn[i] <= RedoRecPtr)
-				{
-					/*
-					 * Oops, this buffer now needs to be backed up, but we
-					 * didn't think so above.  Start over.
-					 */
-					WALInsertLockRelease();
-					END_CRIT_SECTION();
-					rdt_lastnormal->next = NULL;
-					info = info_orig;
-					goto begin;
-				}
-			}
-		}
 	}
+	doPageWrites = (Insert->fullPageWrites || Insert->forcePageWrites);
 
-	/*
-	 * Also check to see if fullPageWrites or forcePageWrites was just turned
-	 * on; if we weren't already doing full-page writes then go back and
-	 * recompute. (If it was just turned off, we could recompute the record
-	 * without full pages, but we choose not to bother.)
-	 */
-	if ((Insert->fullPageWrites || Insert->forcePageWrites) && !doPageWrites)
+	if (fpw_lsn != InvalidXLogRecPtr && fpw_lsn <= RedoRecPtr && doPageWrites)
 	{
-		/* Oops, must redo it with full-page data. */
+		/*
+		 * Oops, some buffer now needs to be backed up that the caller
+		 * didn't back up.  Start over.
+		 */
 		WALInsertLockRelease();
 		END_CRIT_SECTION();
-		rdt_lastnormal->next = NULL;
-		info = info_orig;
-		goto begin;
+		return InvalidXLogRecPtr;
 	}
 
 	/*
@@ -1182,7 +968,7 @@ begin:;
 		inserted = ReserveXLogSwitch(&StartPos, &EndPos, &rechdr->xl_prev);
 	else
 	{
-		ReserveXLogInsertLocation(write_len, &StartPos, &EndPos,
+		ReserveXLogInsertLocation(rechdr->xl_tot_len, &StartPos, &EndPos,
 								  &rechdr->xl_prev);
 		inserted = true;
 	}
@@ -1201,7 +987,8 @@ begin:;
 		 * All the record data, including the header, is now ready to be
 		 * inserted. Copy the record in the space reserved.
 		 */
-		CopyXLogRecordToWAL(write_len, isLogSwitch, &hdr_rdt, StartPos, EndPos);
+		CopyXLogRecordToWAL(rechdr->xl_tot_len, isLogSwitch, rdata,
+							StartPos, EndPos);
 	}
 	else
 	{
@@ -1437,7 +1224,7 @@ ReserveXLogSwitch(XLogRecPtr *StartPos, XLogRecPtr *EndPos, XLogRecPtr *PrevPtr)
 }
 
 /*
- * Subroutine of XLogInsert.  Copies a WAL record to an already-reserved
+ * Subroutine of XLogInsertRecord.  Copies a WAL record to an already-reserved
  * area in the WAL.
  */
 static void
@@ -2003,93 +1790,6 @@ XLogRecPtrToBytePos(XLogRecPtr ptr)
 	return result;
 }
 
-/*
- * Determine whether the buffer referenced has to be backed up.
- *
- * Since we don't yet have the insert lock, fullPageWrites and forcePageWrites
- * could change later, so the result should be used for optimization purposes
- * only.
- */
-bool
-XLogCheckBufferNeedsBackup(Buffer buffer)
-{
-	bool		doPageWrites;
-	Page		page;
-
-	page = BufferGetPage(buffer);
-
-	doPageWrites = XLogCtl->Insert.fullPageWrites || XLogCtl->Insert.forcePageWrites;
-
-	if (doPageWrites && PageGetLSN(page) <= RedoRecPtr)
-		return true;			/* buffer requires backup */
-
-	return false;				/* buffer does not need to be backed up */
-}
-
-/*
- * Determine whether the buffer referenced by an XLogRecData item has to
- * be backed up, and if so fill a BkpBlock struct for it.  In any case
- * save the buffer's LSN at *lsn.
- */
-static bool
-XLogCheckBuffer(XLogRecData *rdata, bool holdsExclusiveLock,
-				XLogRecPtr *lsn, BkpBlock *bkpb)
-{
-	Page		page;
-
-	page = BufferGetPage(rdata->buffer);
-
-	/*
-	 * We assume page LSN is first data on *every* page that can be passed to
-	 * XLogInsert, whether it has the standard page layout or not. We don't
-	 * need to take the buffer header lock for PageGetLSN if we hold an
-	 * exclusive lock on the page and/or the relation.
-	 */
-	if (holdsExclusiveLock)
-		*lsn = PageGetLSN(page);
-	else
-		*lsn = BufferGetLSNAtomic(rdata->buffer);
-
-	if (*lsn <= RedoRecPtr)
-	{
-		/*
-		 * The page needs to be backed up, so set up *bkpb
-		 */
-		BufferGetTag(rdata->buffer, &bkpb->node, &bkpb->fork, &bkpb->block);
-
-		if (rdata->buffer_std)
-		{
-			/* Assume we can omit data between pd_lower and pd_upper */
-			uint16		lower = ((PageHeader) page)->pd_lower;
-			uint16		upper = ((PageHeader) page)->pd_upper;
-
-			if (lower >= SizeOfPageHeaderData &&
-				upper > lower &&
-				upper <= BLCKSZ)
-			{
-				bkpb->hole_offset = lower;
-				bkpb->hole_length = upper - lower;
-			}
-			else
-			{
-				/* No "hole" to compress out */
-				bkpb->hole_offset = 0;
-				bkpb->hole_length = 0;
-			}
-		}
-		else
-		{
-			/* Not a standard page header, don't try to eliminate "hole" */
-			bkpb->hole_offset = 0;
-			bkpb->hole_length = 0;
-		}
-
-		return true;			/* buffer requires backup */
-	}
-
-	return false;				/* buffer does not need to be backed up */
-}
-
 /*
  * Initialize XLOG buffers, writing out old buffers if they still contain
  * unwritten data, upto the page containing 'upto'. Or if 'opportunistic' is
@@ -3943,128 +3643,6 @@ CleanupBackupHistory(void)
 	FreeDir(xldir);
 }
 
-/*
- * Restore a full-page image from a backup block attached to an XLOG record.
- *
- * lsn: LSN of the XLOG record being replayed
- * record: the complete XLOG record
- * block_index: which backup block to restore (0 .. XLR_MAX_BKP_BLOCKS - 1)
- * get_cleanup_lock: TRUE to get a cleanup rather than plain exclusive lock
- * keep_buffer: TRUE to return the buffer still locked and pinned
- *
- * Returns the buffer number containing the page.  Note this is not terribly
- * useful unless keep_buffer is specified as TRUE.
- *
- * Note: when a backup block is available in XLOG, we restore it
- * unconditionally, even if the page in the database appears newer.
- * This is to protect ourselves against database pages that were partially
- * or incorrectly written during a crash.  We assume that the XLOG data
- * must be good because it has passed a CRC check, while the database
- * page might not be.  This will force us to replay all subsequent
- * modifications of the page that appear in XLOG, rather than possibly
- * ignoring them as already applied, but that's not a huge drawback.
- *
- * If 'get_cleanup_lock' is true, a cleanup lock is obtained on the buffer,
- * else a normal exclusive lock is used.  During crash recovery, that's just
- * pro forma because there can't be any regular backends in the system, but
- * in hot standby mode the distinction is important.
- *
- * If 'keep_buffer' is true, return without releasing the buffer lock and pin;
- * then caller is responsible for doing UnlockReleaseBuffer() later.  This
- * is needed in some cases when replaying XLOG records that touch multiple
- * pages, to prevent inconsistent states from being visible to other backends.
- * (Again, that's only important in hot standby mode.)
- */
-Buffer
-RestoreBackupBlock(XLogRecPtr lsn, XLogRecord *record, int block_index,
-				   bool get_cleanup_lock, bool keep_buffer)
-{
-	BkpBlock	bkpb;
-	char	   *blk;
-	int			i;
-
-	/* Locate requested BkpBlock in the record */
-	blk = (char *) XLogRecGetData(record) + record->xl_len;
-	for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
-	{
-		if (!(record->xl_info & XLR_BKP_BLOCK(i)))
-			continue;
-
-		memcpy(&bkpb, blk, sizeof(BkpBlock));
-		blk += sizeof(BkpBlock);
-
-		if (i == block_index)
-		{
-			/* Found it, apply the update */
-			return RestoreBackupBlockContents(lsn, bkpb, blk, get_cleanup_lock,
-											  keep_buffer);
-		}
-
-		blk += BLCKSZ - bkpb.hole_length;
-	}
-
-	/* Caller specified a bogus block_index */
-	elog(ERROR, "failed to restore block_index %d", block_index);
-	return InvalidBuffer;		/* keep compiler quiet */
-}
-
-/*
- * Workhorse for RestoreBackupBlock usable without an xlog record
- *
- * Restores a full-page image from BkpBlock and a data pointer.
- */
-static Buffer
-RestoreBackupBlockContents(XLogRecPtr lsn, BkpBlock bkpb, char *blk,
-						   bool get_cleanup_lock, bool keep_buffer)
-{
-	Buffer		buffer;
-	Page		page;
-
-	buffer = XLogReadBufferExtended(bkpb.node, bkpb.fork, bkpb.block,
-									RBM_ZERO);
-	Assert(BufferIsValid(buffer));
-	if (get_cleanup_lock)
-		LockBufferForCleanup(buffer);
-	else
-		LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
-
-	page = (Page) BufferGetPage(buffer);
-
-	if (bkpb.hole_length == 0)
-	{
-		memcpy((char *) page, blk, BLCKSZ);
-	}
-	else
-	{
-		memcpy((char *) page, blk, bkpb.hole_offset);
-		/* must zero-fill the hole */
-		MemSet((char *) page + bkpb.hole_offset, 0, bkpb.hole_length);
-		memcpy((char *) page + (bkpb.hole_offset + bkpb.hole_length),
-			   blk + bkpb.hole_offset,
-			   BLCKSZ - (bkpb.hole_offset + bkpb.hole_length));
-	}
-
-	/*
-	 * The checksum value on this page is currently invalid. We don't need to
-	 * reset it here since it will be set before being written.
-	 */
-
-	/*
-	 * The page may be uninitialized. If so, we can't set the LSN because that
-	 * would corrupt the page.
-	 */
-	if (!PageIsNew(page))
-	{
-		PageSetLSN(page, lsn);
-	}
-	MarkBufferDirty(buffer);
-
-	if (!keep_buffer)
-		UnlockReleaseBuffer(buffer);
-
-	return buffer;
-}
-
 /*
  * Attempt to read an XLOG record.
  *
@@ -6352,6 +5930,7 @@ StartupXLOG(void)
 	lastFullPageWrites = checkPoint.fullPageWrites;
 
 	RedoRecPtr = XLogCtl->RedoRecPtr = XLogCtl->Insert.RedoRecPtr = checkPoint.redo;
+	doPageWrites = lastFullPageWrites;
 
 	if (RecPtr < checkPoint.redo)
 		ereport(PANIC,
@@ -7606,12 +7185,16 @@ ReadCheckpointRecord(XLogReaderState *xlogreader, XLogRecPtr RecPtr,
 void
 InitXLOGAccess(void)
 {
+	XLogCtlInsert *Insert = &XLogCtl->Insert;
+
 	/* ThisTimeLineID doesn't change so we need no lock to copy it */
 	ThisTimeLineID = XLogCtl->ThisTimeLineID;
 	Assert(ThisTimeLineID != 0 || IsBootstrapProcessingMode());
 
 	/* Use GetRedoRecPtr to copy the RedoRecPtr safely */
 	(void) GetRedoRecPtr();
+	/* Also update our copy of doPageWrites. */
+	doPageWrites = (Insert->fullPageWrites || Insert->forcePageWrites);
 }
 
 /*
@@ -7639,6 +7222,21 @@ GetRedoRecPtr(void)
 	return RedoRecPtr;
 }
 
+/*
+ * Return information needed to decide whether a modified block needs a
+ * full-page image to be included in the WAL record.
+ *
+ * The returned values are cached copies from backend-private memory, and
+ * possibly out-of-date.  XLogInsertRecord will re-check them against
+ * up-to-date values, while holding the WAL insert lock.
+ */
+void
+GetFullPageWriteInfo(XLogRecPtr *RedoRecPtr_p, bool *doPageWrites_p)
+{
+	*RedoRecPtr_p = RedoRecPtr;
+	*doPageWrites_p = doPageWrites;
+}
+
 /*
  * GetInsertRecPtr -- Returns the current insert position.
  *
@@ -8792,218 +8390,6 @@ XLogRestorePoint(const char *rpName)
 	return RecPtr;
 }
 
-/*
- * Write a backup block if needed when we are setting a hint. Note that
- * this may be called for a variety of page types, not just heaps.
- *
- * Callable while holding just share lock on the buffer content.
- *
- * We can't use the plain backup block mechanism since that relies on the
- * Buffer being exclusively locked. Since some modifications (setting LSN, hint
- * bits) are allowed in a sharelocked buffer that can lead to wal checksum
- * failures. So instead we copy the page and insert the copied data as normal
- * record data.
- *
- * We only need to do something if page has not yet been full page written in
- * this checkpoint round. The LSN of the inserted wal record is returned if we
- * had to write, InvalidXLogRecPtr otherwise.
- *
- * It is possible that multiple concurrent backends could attempt to write WAL
- * records. In that case, multiple copies of the same block would be recorded
- * in separate WAL records by different backends, though that is still OK from
- * a correctness perspective.
- */
-XLogRecPtr
-XLogSaveBufferForHint(Buffer buffer, bool buffer_std)
-{
-	XLogRecPtr	recptr = InvalidXLogRecPtr;
-	XLogRecPtr	lsn;
-	XLogRecData rdata[2];
-	BkpBlock	bkpb;
-
-	/*
-	 * Ensure no checkpoint can change our view of RedoRecPtr.
-	 */
-	Assert(MyPgXact->delayChkpt);
-
-	/*
-	 * Update RedoRecPtr so XLogCheckBuffer can make the right decision
-	 */
-	GetRedoRecPtr();
-
-	/*
-	 * Setup phony rdata element for use within XLogCheckBuffer only. We reuse
-	 * and reset rdata for any actual WAL record insert.
-	 */
-	rdata[0].buffer = buffer;
-	rdata[0].buffer_std = buffer_std;
-
-	/*
-	 * Check buffer while not holding an exclusive lock.
-	 */
-	if (XLogCheckBuffer(rdata, false, &lsn, &bkpb))
-	{
-		char		copied_buffer[BLCKSZ];
-		char	   *origdata = (char *) BufferGetBlock(buffer);
-
-		/*
-		 * Copy buffer so we don't have to worry about concurrent hint bit or
-		 * lsn updates. We assume pd_lower/upper cannot be changed without an
-		 * exclusive lock, so the contents bkp are not racy.
-		 *
-		 * With buffer_std set to false, XLogCheckBuffer() sets hole_length
-		 * and hole_offset to 0; so the following code is safe for either
-		 * case.
-		 */
-		memcpy(copied_buffer, origdata, bkpb.hole_offset);
-		memcpy(copied_buffer + bkpb.hole_offset,
-			   origdata + bkpb.hole_offset + bkpb.hole_length,
-			   BLCKSZ - bkpb.hole_offset - bkpb.hole_length);
-
-		/*
-		 * Header for backup block.
-		 */
-		rdata[0].data = (char *) &bkpb;
-		rdata[0].len = sizeof(BkpBlock);
-		rdata[0].buffer = InvalidBuffer;
-		rdata[0].next = &(rdata[1]);
-
-		/*
-		 * Save copy of the buffer.
-		 */
-		rdata[1].data = copied_buffer;
-		rdata[1].len = BLCKSZ - bkpb.hole_length;
-		rdata[1].buffer = InvalidBuffer;
-		rdata[1].next = NULL;
-
-		recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI, rdata);
-	}
-
-	return recptr;
-}
-
-/*
- * Write a WAL record containing a full image of a page. Caller is responsible
- * for writing the page to disk after calling this routine.
- *
- * Note: If you're using this function, you should be building pages in private
- * memory and writing them directly to smgr.  If you're using buffers, call
- * log_newpage_buffer instead.
- *
- * If the page follows the standard page layout, with a PageHeader and unused
- * space between pd_lower and pd_upper, set 'page_std' to TRUE. That allows
- * the unused space to be left out from the WAL record, making it smaller.
- */
-XLogRecPtr
-log_newpage(RelFileNode *rnode, ForkNumber forkNum, BlockNumber blkno,
-			Page page, bool page_std)
-{
-	BkpBlock	bkpb;
-	XLogRecPtr	recptr;
-	XLogRecData rdata[3];
-
-	/* NO ELOG(ERROR) from here till newpage op is logged */
-	START_CRIT_SECTION();
-
-	bkpb.node = *rnode;
-	bkpb.fork = forkNum;
-	bkpb.block = blkno;
-
-	if (page_std)
-	{
-		/* Assume we can omit data between pd_lower and pd_upper */
-		uint16		lower = ((PageHeader) page)->pd_lower;
-		uint16		upper = ((PageHeader) page)->pd_upper;
-
-		if (lower >= SizeOfPageHeaderData &&
-			upper > lower &&
-			upper <= BLCKSZ)
-		{
-			bkpb.hole_offset = lower;
-			bkpb.hole_length = upper - lower;
-		}
-		else
-		{
-			/* No "hole" to compress out */
-			bkpb.hole_offset = 0;
-			bkpb.hole_length = 0;
-		}
-	}
-	else
-	{
-		/* Not a standard page header, don't try to eliminate "hole" */
-		bkpb.hole_offset = 0;
-		bkpb.hole_length = 0;
-	}
-
-	rdata[0].data = (char *) &bkpb;
-	rdata[0].len = sizeof(BkpBlock);
-	rdata[0].buffer = InvalidBuffer;
-	rdata[0].next = &(rdata[1]);
-
-	if (bkpb.hole_length == 0)
-	{
-		rdata[1].data = (char *) page;
-		rdata[1].len = BLCKSZ;
-		rdata[1].buffer = InvalidBuffer;
-		rdata[1].next = NULL;
-	}
-	else
-	{
-		/* must skip the hole */
-		rdata[1].data = (char *) page;
-		rdata[1].len = bkpb.hole_offset;
-		rdata[1].buffer = InvalidBuffer;
-		rdata[1].next = &rdata[2];
-
-		rdata[2].data = (char *) page + (bkpb.hole_offset + bkpb.hole_length);
-		rdata[2].len = BLCKSZ - (bkpb.hole_offset + bkpb.hole_length);
-		rdata[2].buffer = InvalidBuffer;
-		rdata[2].next = NULL;
-	}
-
-	recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI, rdata);
-
-	/*
-	 * The page may be uninitialized. If so, we can't set the LSN because that
-	 * would corrupt the page.
-	 */
-	if (!PageIsNew(page))
-	{
-		PageSetLSN(page, recptr);
-	}
-
-	END_CRIT_SECTION();
-
-	return recptr;
-}
-
-/*
- * Write a WAL record containing a full image of a page.
- *
- * Caller should initialize the buffer and mark it dirty before calling this
- * function.  This function will set the page LSN.
- *
- * If the page follows the standard page layout, with a PageHeader and unused
- * space between pd_lower and pd_upper, set 'page_std' to TRUE. That allows
- * the unused space to be left out from the WAL record, making it smaller.
- */
-XLogRecPtr
-log_newpage_buffer(Buffer buffer, bool page_std)
-{
-	Page		page = BufferGetPage(buffer);
-	RelFileNode rnode;
-	ForkNumber	forkNum;
-	BlockNumber blkno;
-
-	/* Shared buffers should be modified in a critical section. */
-	Assert(CritSectionCount > 0);
-
-	BufferGetTag(buffer, &rnode, &forkNum, &blkno);
-
-	return log_newpage(&rnode, forkNum, blkno, page, page_std);
-}
-
 /*
  * Check if any of the GUC parameters that are critical for hot standby
  * have changed, and update the value in pg_control file if necessary.
@@ -9757,7 +9143,8 @@ do_pg_start_backup(const char *backupidstr, bool fast, TimeLineID *starttli_p,
 	 * the standby.
 	 *
 	 * We must hold all the insertion locks to change the value of
-	 * forcePageWrites, to ensure adequate interlocking against XLogInsert().
+	 * forcePageWrites, to ensure adequate interlocking against
+	 * XLogInsertRecord().
 	 */
 	WALInsertLockAcquireExclusive();
 	if (exclusive)
diff --git a/src/backend/access/transam/xloginsert.c b/src/backend/access/transam/xloginsert.c
new file mode 100644
index 0000000000..b83343bf5b
--- /dev/null
+++ b/src/backend/access/transam/xloginsert.c
@@ -0,0 +1,633 @@
+/*-------------------------------------------------------------------------
+ *
+ * xloginsert.c
+ *		Functions for constructing WAL records
+ *
+ * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/backend/access/transam/xloginsert.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/xact.h"
+#include "access/xlog.h"
+#include "access/xlog_internal.h"
+#include "access/xloginsert.h"
+#include "catalog/pg_control.h"
+#include "miscadmin.h"
+#include "storage/bufmgr.h"
+#include "storage/proc.h"
+#include "utils/memutils.h"
+#include "pg_trace.h"
+
+static XLogRecData *XLogRecordAssemble(RmgrId rmid, uint8 info,
+				   XLogRecData *rdata,
+				   XLogRecPtr RedoRecPtr, bool doPageWrites,
+				   XLogRecPtr *fpw_lsn, XLogRecData **rdt_lastnormal);
+static void XLogFillBkpBlock(Buffer buffer, bool buffer_std, BkpBlock *bkpb);
+
+/*
+ * Insert an XLOG record having the specified RMID and info bytes,
+ * with the body of the record being the data chunk(s) described by
+ * the rdata chain (see xloginsert.h for notes about rdata).
+ *
+ * Returns XLOG pointer to end of record (beginning of next record).
+ * This can be used as LSN for data pages affected by the logged action.
+ * (LSN is the XLOG point up to which the XLOG must be flushed to disk
+ * before the data page can be written out.  This implements the basic
+ * WAL rule "write the log before the data".)
+ *
+ * NB: this routine feels free to scribble on the XLogRecData structs,
+ * though not on the data they reference.  This is OK since the XLogRecData
+ * structs are always just temporaries in the calling code.
+ */
+XLogRecPtr
+XLogInsert(RmgrId rmid, uint8 info, XLogRecData *rdata)
+{
+	XLogRecPtr	RedoRecPtr;
+	bool		doPageWrites;
+	XLogRecPtr	EndPos;
+	XLogRecPtr	fpw_lsn;
+	XLogRecData *rdt;
+	XLogRecData *rdt_lastnormal;
+
+	/* info's high bits are reserved for use by me */
+	if (info & XLR_INFO_MASK)
+		elog(PANIC, "invalid xlog info mask %02X", info);
+
+	TRACE_POSTGRESQL_XLOG_INSERT(rmid, info);
+
+	/*
+	 * In bootstrap mode, we don't actually log anything but XLOG resources;
+	 * return a phony record pointer.
+	 */
+	if (IsBootstrapProcessingMode() && rmid != RM_XLOG_ID)
+	{
+		EndPos = SizeOfXLogLongPHD;		/* start of 1st chkpt record */
+		return EndPos;
+	}
+
+	/*
+	 * Get values needed to decide whether to do full-page writes. Since we
+	 * don't yet have an insertion lock, these could change under us, but
+	 * XLogInsertRecord will recheck them once it has a lock.
+	 */
+	GetFullPageWriteInfo(&RedoRecPtr, &doPageWrites);
+
+	/*
+	 * Assemble an XLogRecData chain representing the WAL record, including
+	 * any backup blocks needed.
+	 *
+	 * We may have to loop back to here if a race condition is detected in
+	 * XLogInsertRecord.  We could prevent the race by doing all this work
+	 * while holding an insertion lock, but it seems better to avoid doing CRC
+	 * calculations while holding one.
+	 */
+retry:
+	rdt = XLogRecordAssemble(rmid, info, rdata, RedoRecPtr, doPageWrites,
+							 &fpw_lsn, &rdt_lastnormal);
+
+	EndPos = XLogInsertRecord(rdt, fpw_lsn);
+
+	if (EndPos == InvalidXLogRecPtr)
+	{
+		/*
+		 * Undo the changes we made to the rdata chain, and retry.
+		 *
+		 * XXX: This doesn't undo *all* the changes; the XLogRecData
+		 * entries for buffers that we had already decided to back up have
+		 * had their data-pointers cleared. That's OK, as long as we
+		 * decide to back them up on the next iteration as well. Hence,
+		 * don't allow "doPageWrites" value to go from true to false after
+		 * we've modified the rdata chain.
+		 */
+		bool		newDoPageWrites;
+
+		GetFullPageWriteInfo(&RedoRecPtr, &newDoPageWrites);
+		doPageWrites = doPageWrites || newDoPageWrites;
+		rdt_lastnormal->next = NULL;
+
+		goto retry;
+	}
+
+	return EndPos;
+}
+
+/*
+ * Assemble a full WAL record, including backup blocks, from an XLogRecData
+ * chain, ready for insertion with XLogInsertRecord(). The record header
+ * fields are filled in, except for the xl_prev field and CRC.
+ *
+ * The rdata chain is modified, adding entries for full-page images.
+ * *rdt_lastnormal is set to point to the last normal (ie. not added by
+ * this function) entry. It can be used to reset the chain to its original
+ * state.
+ *
+ * If the rdata chain contains any buffer references, and a full-page image
+ * was not taken of all the buffers, *fpw_lsn is set to the lowest LSN among
+ * such pages. This signals that the assembled record is only good for
+ * insertion on the assumption that the RedoRecPtr and doPageWrites values
+ * were up-to-date.
+ */
+static XLogRecData *
+XLogRecordAssemble(RmgrId rmid, uint8 info, XLogRecData *rdata,
+				   XLogRecPtr RedoRecPtr, bool doPageWrites,
+				   XLogRecPtr *fpw_lsn, XLogRecData **rdt_lastnormal)
+{
+	bool		isLogSwitch = (rmid == RM_XLOG_ID && info == XLOG_SWITCH);
+	XLogRecData *rdt;
+	Buffer		dtbuf[XLR_MAX_BKP_BLOCKS];
+	bool		dtbuf_bkp[XLR_MAX_BKP_BLOCKS];
+	uint32		len,
+				total_len;
+	unsigned	i;
+
+	/*
+	 * These need to be static because they are returned to the caller as part
+	 * of the XLogRecData chain.
+	 */
+	static BkpBlock dtbuf_xlg[XLR_MAX_BKP_BLOCKS];
+	static XLogRecData dtbuf_rdt1[XLR_MAX_BKP_BLOCKS];
+	static XLogRecData dtbuf_rdt2[XLR_MAX_BKP_BLOCKS];
+	static XLogRecData dtbuf_rdt3[XLR_MAX_BKP_BLOCKS];
+	static XLogRecData hdr_rdt;
+	static XLogRecord *rechdr;
+
+	if (rechdr == NULL)
+	{
+		static char rechdrbuf[SizeOfXLogRecord + MAXIMUM_ALIGNOF];
+
+		rechdr = (XLogRecord *) MAXALIGN(&rechdrbuf);
+		MemSet(rechdr, 0, SizeOfXLogRecord);
+	}
+
+	/* The record begins with the header */
+	hdr_rdt.data = (char *) rechdr;
+	hdr_rdt.len = SizeOfXLogRecord;
+	hdr_rdt.next = rdata;
+	total_len = SizeOfXLogRecord;
+
+	/*
+	 * Here we scan the rdata chain, to determine which buffers must be backed
+	 * up.
+	 *
+	 * We add entries for backup blocks to the chain, so that they don't need
+	 * any special treatment in the critical section where the chunks are
+	 * copied into the WAL buffers. Those entries have to be unlinked from the
+	 * chain if we have to loop back here.
+	 */
+	for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
+	{
+		dtbuf[i] = InvalidBuffer;
+		dtbuf_bkp[i] = false;
+	}
+
+	*fpw_lsn = InvalidXLogRecPtr;
+	len = 0;
+	for (rdt = rdata;;)
+	{
+		if (rdt->buffer == InvalidBuffer)
+		{
+			/* Simple data, just include it */
+			len += rdt->len;
+		}
+		else
+		{
+			/* Find info for buffer */
+			for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
+			{
+				if (rdt->buffer == dtbuf[i])
+				{
+					/* Buffer already referenced by earlier chain item */
+					if (dtbuf_bkp[i])
+					{
+						rdt->data = NULL;
+						rdt->len = 0;
+					}
+					else if (rdt->data)
+						len += rdt->len;
+					break;
+				}
+				if (dtbuf[i] == InvalidBuffer)
+				{
+					/* OK, put it in this slot */
+					XLogRecPtr	page_lsn;
+					bool		needs_backup;
+
+					dtbuf[i] = rdt->buffer;
+
+					/*
+					 * Determine whether the buffer has to be backed up.
+					 *
+					 * We assume page LSN is first data on *every* page that
+					 * can be passed to XLogInsert, whether it has the
+					 * standard page layout or not. We don't need to take the
+					 * buffer header lock for PageGetLSN because we hold an
+					 * exclusive lock on the page and/or the relation.
+					 */
+					page_lsn = PageGetLSN(BufferGetPage(rdt->buffer));
+					if (!doPageWrites)
+						needs_backup = false;
+					else if (page_lsn <= RedoRecPtr)
+						needs_backup = true;
+					else
+						needs_backup = false;
+
+					if (needs_backup)
+					{
+						/*
+						 * The page needs to be backed up, so set up BkpBlock
+						 */
+						XLogFillBkpBlock(rdt->buffer, rdt->buffer_std,
+										 &(dtbuf_xlg[i]));
+						dtbuf_bkp[i] = true;
+						rdt->data = NULL;
+						rdt->len = 0;
+					}
+					else
+					{
+						if (rdt->data)
+							len += rdt->len;
+						if (*fpw_lsn == InvalidXLogRecPtr ||
+							page_lsn < *fpw_lsn)
+						{
+							*fpw_lsn = page_lsn;
+						}
+					}
+					break;
+				}
+			}
+			if (i >= XLR_MAX_BKP_BLOCKS)
+				elog(PANIC, "can backup at most %d blocks per xlog record",
+					 XLR_MAX_BKP_BLOCKS);
+		}
+		/* Break out of loop when rdt points to last chain item */
+		if (rdt->next == NULL)
+			break;
+		rdt = rdt->next;
+	}
+	total_len += len;
+
+	/*
+	 * Make additional rdata chain entries for the backup blocks, so that we
+	 * don't need to special-case them in the write loop.  This modifies the
+	 * original rdata chain, but we keep a pointer to the last regular entry,
+	 * rdt_lastnormal, so that we can undo this if we have to start over.
+	 *
+	 * At the exit of this loop, total_len includes the backup block data.
+	 *
+	 * Also set the appropriate info bits to show which buffers were backed
+	 * up. The XLR_BKP_BLOCK(N) bit corresponds to the N'th distinct buffer
+	 * value (ignoring InvalidBuffer) appearing in the rdata chain.
+	 */
+	*rdt_lastnormal = rdt;
+	for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
+	{
+		BkpBlock   *bkpb;
+		char	   *page;
+
+		if (!dtbuf_bkp[i])
+			continue;
+
+		info |= XLR_BKP_BLOCK(i);
+
+		bkpb = &(dtbuf_xlg[i]);
+		page = (char *) BufferGetBlock(dtbuf[i]);
+
+		rdt->next = &(dtbuf_rdt1[i]);
+		rdt = rdt->next;
+
+		rdt->data = (char *) bkpb;
+		rdt->len = sizeof(BkpBlock);
+		total_len += sizeof(BkpBlock);
+
+		rdt->next = &(dtbuf_rdt2[i]);
+		rdt = rdt->next;
+
+		if (bkpb->hole_length == 0)
+		{
+			rdt->data = page;
+			rdt->len = BLCKSZ;
+			total_len += BLCKSZ;
+			rdt->next = NULL;
+		}
+		else
+		{
+			/* must skip the hole */
+			rdt->data = page;
+			rdt->len = bkpb->hole_offset;
+			total_len += bkpb->hole_offset;
+
+			rdt->next = &(dtbuf_rdt3[i]);
+			rdt = rdt->next;
+
+			rdt->data = page + (bkpb->hole_offset + bkpb->hole_length);
+			rdt->len = BLCKSZ - (bkpb->hole_offset + bkpb->hole_length);
+			total_len += rdt->len;
+			rdt->next = NULL;
+		}
+	}
+
+	/*
+	 * We disallow len == 0 because it provides a useful bit of extra error
+	 * checking in ReadRecord.  This means that all callers of XLogInsert
+	 * must supply at least some not-in-a-buffer data.  However, we make an
+	 * exception for XLOG SWITCH records because we don't want them to ever
+	 * cross a segment boundary.
+	 */
+	if (len == 0 && !isLogSwitch)
+		elog(PANIC, "invalid xlog record length %u", rechdr->xl_len);
+
+	/*
+	 * Fill in the fields in the record header. Prev-link is filled in later,
+	 * once we know where in the WAL the record will be inserted. CRC is also
+	 * not calculated yet.
+	 */
+	rechdr->xl_xid = GetCurrentTransactionIdIfAny();
+	rechdr->xl_tot_len = total_len;
+	rechdr->xl_len = len;		/* doesn't include backup blocks */
+	rechdr->xl_info = info;
+	rechdr->xl_rmid = rmid;
+	rechdr->xl_prev = InvalidXLogRecPtr;
+
+	return &hdr_rdt;
+}
+
+/*
+ * Determine whether the buffer referenced has to be backed up.
+ *
+ * Since we don't yet have the insert lock, fullPageWrites and forcePageWrites
+ * could change later, so the result should be used for optimization purposes
+ * only.
+ */
+bool
+XLogCheckBufferNeedsBackup(Buffer buffer)
+{
+	XLogRecPtr	RedoRecPtr;
+	bool		doPageWrites;
+	Page		page;
+
+	GetFullPageWriteInfo(&RedoRecPtr, &doPageWrites);
+
+	page = BufferGetPage(buffer);
+
+	if (doPageWrites && PageGetLSN(page) <= RedoRecPtr)
+		return true;			/* buffer requires backup */
+
+	return false;				/* buffer does not need to be backed up */
+}
+
+/*
+ * Write a backup block if needed when we are setting a hint. Note that
+ * this may be called for a variety of page types, not just heaps.
+ *
+ * Callable while holding just share lock on the buffer content.
+ *
+ * We can't use the plain backup block mechanism since that relies on the
+ * Buffer being exclusively locked. Since some modifications (setting LSN, hint
+ * bits) are allowed in a sharelocked buffer that can lead to wal checksum
+ * failures. So instead we copy the page and insert the copied data as normal
+ * record data.
+ *
+ * We only need to do something if page has not yet been full page written in
+ * this checkpoint round. The LSN of the inserted wal record is returned if we
+ * had to write, InvalidXLogRecPtr otherwise.
+ *
+ * It is possible that multiple concurrent backends could attempt to write WAL
+ * records. In that case, multiple copies of the same block would be recorded
+ * in separate WAL records by different backends, though that is still OK from
+ * a correctness perspective.
+ */
+XLogRecPtr
+XLogSaveBufferForHint(Buffer buffer, bool buffer_std)
+{
+	XLogRecPtr	recptr = InvalidXLogRecPtr;
+	XLogRecPtr	lsn;
+	XLogRecPtr	RedoRecPtr;
+
+	/*
+	 * Ensure no checkpoint can change our view of RedoRecPtr.
+	 */
+	Assert(MyPgXact->delayChkpt);
+
+	/*
+	 * Update RedoRecPtr so that we can make the right decision
+	 */
+	RedoRecPtr = GetRedoRecPtr();
+
+	/*
+	 * We assume page LSN is first data on *every* page that can be passed to
+	 * XLogInsert, whether it has the standard page layout or not. Since we're
+	 * only holding a share-lock on the page, we must take the buffer header
+	 * lock when we look at the LSN.
+	 */
+	lsn = BufferGetLSNAtomic(buffer);
+
+	if (lsn <= RedoRecPtr)
+	{
+		XLogRecData rdata[2];
+		BkpBlock	bkpb;
+		char		copied_buffer[BLCKSZ];
+		char	   *origdata = (char *) BufferGetBlock(buffer);
+
+		/* Make a BkpBlock struct representing the buffer */
+		XLogFillBkpBlock(buffer, buffer_std, &bkpb);
+
+		/*
+		 * Copy buffer so we don't have to worry about concurrent hint bit or
+		 * lsn updates. We assume pd_lower/upper cannot be changed without an
+		 * exclusive lock, so the contents bkp are not racy.
+		 *
+		 * With buffer_std set to false, XLogFillBkpBlock() sets hole_length
+		 * and hole_offset to 0; so the following code is safe for either
+		 * case.
+		 */
+		memcpy(copied_buffer, origdata, bkpb.hole_offset);
+		memcpy(copied_buffer + bkpb.hole_offset,
+			   origdata + bkpb.hole_offset + bkpb.hole_length,
+			   BLCKSZ - bkpb.hole_offset - bkpb.hole_length);
+
+		/*
+		 * Header for backup block.
+		 */
+		rdata[0].data = (char *) &bkpb;
+		rdata[0].len = sizeof(BkpBlock);
+		rdata[0].buffer = InvalidBuffer;
+		rdata[0].next = &(rdata[1]);
+
+		/*
+		 * Save copy of the buffer.
+		 */
+		rdata[1].data = copied_buffer;
+		rdata[1].len = BLCKSZ - bkpb.hole_length;
+		rdata[1].buffer = InvalidBuffer;
+		rdata[1].next = NULL;
+
+		recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI, rdata);
+	}
+
+	return recptr;
+}
+
+/*
+ * Write a WAL record containing a full image of a page. Caller is responsible
+ * for writing the page to disk after calling this routine.
+ *
+ * Note: If you're using this function, you should be building pages in private
+ * memory and writing them directly to smgr.  If you're using buffers, call
+ * log_newpage_buffer instead.
+ *
+ * If the page follows the standard page layout, with a PageHeader and unused
+ * space between pd_lower and pd_upper, set 'page_std' to TRUE. That allows
+ * the unused space to be left out from the WAL record, making it smaller.
+ */
+XLogRecPtr
+log_newpage(RelFileNode *rnode, ForkNumber forkNum, BlockNumber blkno,
+			Page page, bool page_std)
+{
+	BkpBlock	bkpb;
+	XLogRecPtr	recptr;
+	XLogRecData rdata[3];
+
+	/* NO ELOG(ERROR) from here till newpage op is logged */
+	START_CRIT_SECTION();
+
+	bkpb.node = *rnode;
+	bkpb.fork = forkNum;
+	bkpb.block = blkno;
+
+	if (page_std)
+	{
+		/* Assume we can omit data between pd_lower and pd_upper */
+		uint16		lower = ((PageHeader) page)->pd_lower;
+		uint16		upper = ((PageHeader) page)->pd_upper;
+
+		if (lower >= SizeOfPageHeaderData &&
+			upper > lower &&
+			upper <= BLCKSZ)
+		{
+			bkpb.hole_offset = lower;
+			bkpb.hole_length = upper - lower;
+		}
+		else
+		{
+			/* No "hole" to compress out */
+			bkpb.hole_offset = 0;
+			bkpb.hole_length = 0;
+		}
+	}
+	else
+	{
+		/* Not a standard page header, don't try to eliminate "hole" */
+		bkpb.hole_offset = 0;
+		bkpb.hole_length = 0;
+	}
+
+	rdata[0].data = (char *) &bkpb;
+	rdata[0].len = sizeof(BkpBlock);
+	rdata[0].buffer = InvalidBuffer;
+	rdata[0].next = &(rdata[1]);
+
+	if (bkpb.hole_length == 0)
+	{
+		rdata[1].data = (char *) page;
+		rdata[1].len = BLCKSZ;
+		rdata[1].buffer = InvalidBuffer;
+		rdata[1].next = NULL;
+	}
+	else
+	{
+		/* must skip the hole */
+		rdata[1].data = (char *) page;
+		rdata[1].len = bkpb.hole_offset;
+		rdata[1].buffer = InvalidBuffer;
+		rdata[1].next = &rdata[2];
+
+		rdata[2].data = (char *) page + (bkpb.hole_offset + bkpb.hole_length);
+		rdata[2].len = BLCKSZ - (bkpb.hole_offset + bkpb.hole_length);
+		rdata[2].buffer = InvalidBuffer;
+		rdata[2].next = NULL;
+	}
+
+	recptr = XLogInsert(RM_XLOG_ID, XLOG_FPI, rdata);
+
+	/*
+	 * The page may be uninitialized. If so, we can't set the LSN because that
+	 * would corrupt the page.
+	 */
+	if (!PageIsNew(page))
+	{
+		PageSetLSN(page, recptr);
+	}
+
+	END_CRIT_SECTION();
+
+	return recptr;
+}
+
+/*
+ * Write a WAL record containing a full image of a page.
+ *
+ * Caller should initialize the buffer and mark it dirty before calling this
+ * function.  This function will set the page LSN.
+ *
+ * If the page follows the standard page layout, with a PageHeader and unused
+ * space between pd_lower and pd_upper, set 'page_std' to TRUE. That allows
+ * the unused space to be left out from the WAL record, making it smaller.
+ */
+XLogRecPtr
+log_newpage_buffer(Buffer buffer, bool page_std)
+{
+	Page		page = BufferGetPage(buffer);
+	RelFileNode rnode;
+	ForkNumber	forkNum;
+	BlockNumber blkno;
+
+	/* Shared buffers should be modified in a critical section. */
+	Assert(CritSectionCount > 0);
+
+	BufferGetTag(buffer, &rnode, &forkNum, &blkno);
+
+	return log_newpage(&rnode, forkNum, blkno, page, page_std);
+}
+
+/*
+ * Fill a BkpBlock for a buffer.
+ */
+static void
+XLogFillBkpBlock(Buffer buffer, bool buffer_std, BkpBlock *bkpb)
+{
+	BufferGetTag(buffer, &bkpb->node, &bkpb->fork, &bkpb->block);
+
+	if (buffer_std)
+	{
+		/* Assume we can omit data between pd_lower and pd_upper */
+		Page		page = BufferGetPage(buffer);
+		uint16		lower = ((PageHeader) page)->pd_lower;
+		uint16		upper = ((PageHeader) page)->pd_upper;
+
+		if (lower >= SizeOfPageHeaderData &&
+			upper > lower &&
+			upper <= BLCKSZ)
+		{
+			bkpb->hole_offset = lower;
+			bkpb->hole_length = upper - lower;
+		}
+		else
+		{
+			/* No "hole" to compress out */
+			bkpb->hole_offset = 0;
+			bkpb->hole_length = 0;
+		}
+	}
+	else
+	{
+		/* Not a standard page header, don't try to eliminate "hole" */
+		bkpb->hole_offset = 0;
+		bkpb->hole_length = 0;
+	}
+}
diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index da7ed92941..7d573cc585 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -16,7 +16,7 @@
 #include "postgres.h"
 
 #include "access/transam.h"
-#include "access/xlog.h"
+#include "access/xlogrecord.h"
 #include "access/xlog_internal.h"
 #include "access/xlogreader.h"
 #include "catalog/pg_control.h"
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index ef827dbc40..1a21dac853 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -456,6 +456,127 @@ XLogReadBufferExtended(RelFileNode rnode, ForkNumber forknum,
 	return buffer;
 }
 
+/*
+ * Restore a full-page image from a backup block attached to an XLOG record.
+ *
+ * lsn: LSN of the XLOG record being replayed
+ * record: the complete XLOG record
+ * block_index: which backup block to restore (0 .. XLR_MAX_BKP_BLOCKS - 1)
+ * get_cleanup_lock: TRUE to get a cleanup rather than plain exclusive lock
+ * keep_buffer: TRUE to return the buffer still locked and pinned
+ *
+ * Returns the buffer number containing the page.  Note this is not terribly
+ * useful unless keep_buffer is specified as TRUE.
+ *
+ * Note: when a backup block is available in XLOG, we restore it
+ * unconditionally, even if the page in the database appears newer.
+ * This is to protect ourselves against database pages that were partially
+ * or incorrectly written during a crash.  We assume that the XLOG data
+ * must be good because it has passed a CRC check, while the database
+ * page might not be.  This will force us to replay all subsequent
+ * modifications of the page that appear in XLOG, rather than possibly
+ * ignoring them as already applied, but that's not a huge drawback.
+ *
+ * If 'get_cleanup_lock' is true, a cleanup lock is obtained on the buffer,
+ * else a normal exclusive lock is used.  During crash recovery, that's just
+ * pro forma because there can't be any regular backends in the system, but
+ * in hot standby mode the distinction is important.
+ *
+ * If 'keep_buffer' is true, return without releasing the buffer lock and pin;
+ * then caller is responsible for doing UnlockReleaseBuffer() later.  This
+ * is needed in some cases when replaying XLOG records that touch multiple
+ * pages, to prevent inconsistent states from being visible to other backends.
+ * (Again, that's only important in hot standby mode.)
+ */
+Buffer
+RestoreBackupBlock(XLogRecPtr lsn, XLogRecord *record, int block_index,
+				   bool get_cleanup_lock, bool keep_buffer)
+{
+	BkpBlock	bkpb;
+	char	   *blk;
+	int			i;
+
+	/* Locate requested BkpBlock in the record */
+	blk = (char *) XLogRecGetData(record) + record->xl_len;
+	for (i = 0; i < XLR_MAX_BKP_BLOCKS; i++)
+	{
+		if (!(record->xl_info & XLR_BKP_BLOCK(i)))
+			continue;
+
+		memcpy(&bkpb, blk, sizeof(BkpBlock));
+		blk += sizeof(BkpBlock);
+
+		if (i == block_index)
+		{
+			/* Found it, apply the update */
+			return RestoreBackupBlockContents(lsn, bkpb, blk, get_cleanup_lock,
+											  keep_buffer);
+		}
+
+		blk += BLCKSZ - bkpb.hole_length;
+	}
+
+	/* Caller specified a bogus block_index */
+	elog(ERROR, "failed to restore block_index %d", block_index);
+	return InvalidBuffer;		/* keep compiler quiet */
+}
+
+/*
+ * Workhorse for RestoreBackupBlock usable without an xlog record
+ *
+ * Restores a full-page image from BkpBlock and a data pointer.
+ */
+Buffer
+RestoreBackupBlockContents(XLogRecPtr lsn, BkpBlock bkpb, char *blk,
+						   bool get_cleanup_lock, bool keep_buffer)
+{
+	Buffer		buffer;
+	Page		page;
+
+	buffer = XLogReadBufferExtended(bkpb.node, bkpb.fork, bkpb.block,
+									RBM_ZERO);
+	Assert(BufferIsValid(buffer));
+	if (get_cleanup_lock)
+		LockBufferForCleanup(buffer);
+	else
+		LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
+
+	page = (Page) BufferGetPage(buffer);
+
+	if (bkpb.hole_length == 0)
+	{
+		memcpy((char *) page, blk, BLCKSZ);
+	}
+	else
+	{
+		memcpy((char *) page, blk, bkpb.hole_offset);
+		/* must zero-fill the hole */
+		MemSet((char *) page + bkpb.hole_offset, 0, bkpb.hole_length);
+		memcpy((char *) page + (bkpb.hole_offset + bkpb.hole_length),
+			   blk + bkpb.hole_offset,
+			   BLCKSZ - (bkpb.hole_offset + bkpb.hole_length));
+	}
+
+	/*
+	 * The checksum value on this page is currently invalid. We don't need to
+	 * reset it here since it will be set before being written.
+	 */
+
+	/*
+	 * The page may be uninitialized. If so, we can't set the LSN because that
+	 * would corrupt the page.
+	 */
+	if (!PageIsNew(page))
+	{
+		PageSetLSN(page, lsn);
+	}
+	MarkBufferDirty(buffer);
+
+	if (!keep_buffer)
+		UnlockReleaseBuffer(buffer);
+
+	return buffer;
+}
 
 /*
  * Struct actually returned by XLogFakeRelcacheEntry, though the declared
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index c0eade0a3d..e523ee923a 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -34,6 +34,7 @@
 #include "access/sysattr.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "catalog/binary_upgrade.h"
 #include "catalog/catalog.h"
 #include "catalog/dependency.h"
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 5eb8fd4cd0..911f015f27 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -21,6 +21,7 @@
 
 #include "access/htup_details.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "catalog/dependency.h"
 #include "catalog/objectaccess.h"
 #include "catalog/pg_authid.h"
diff --git a/src/backend/catalog/storage.c b/src/backend/catalog/storage.c
index c3b2f072e4..46780e71d6 100644
--- a/src/backend/catalog/storage.c
+++ b/src/backend/catalog/storage.c
@@ -21,6 +21,8 @@
 
 #include "access/visibilitymap.h"
 #include "access/xact.h"
+#include "access/xlog.h"
+#include "access/xloginsert.h"
 #include "access/xlogutils.h"
 #include "catalog/catalog.h"
 #include "catalog/storage.h"
diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index ff80b09c10..6a578ec58f 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -23,6 +23,7 @@
 #include "access/transam.h"
 #include "access/tuptoaster.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "catalog/catalog.h"
 #include "catalog/dependency.h"
 #include "catalog/heap.h"
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 6b8357634a..83e8f89122 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -24,6 +24,7 @@
 #include "access/htup_details.h"
 #include "access/sysattr.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_type.h"
 #include "commands/copy.h"
diff --git a/src/backend/commands/createas.c b/src/backend/commands/createas.c
index e381c06e67..5e0ac58560 100644
--- a/src/backend/commands/createas.c
+++ b/src/backend/commands/createas.c
@@ -27,6 +27,7 @@
 #include "access/htup_details.h"
 #include "access/sysattr.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "catalog/toasting.h"
 #include "commands/createas.h"
 #include "commands/matview.h"
diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index 45f525d1d4..94c82d3741 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -28,6 +28,7 @@
 #include "access/heapam.h"
 #include "access/htup_details.h"
 #include "access/xact.h"
+#include "access/xloginsert.h"
 #include "access/xlogutils.h"
 #include "catalog/catalog.h"
 #include "catalog/dependency.h"
diff --git a/src/backend/commands/matview.c b/src/backend/commands/matview.c
index db05f7cf80..523ba35ba2 100644
--- a/src/backend/commands/matview.c
+++ b/src/backend/commands/matview.c
@@ -17,6 +17,7 @@
 #include "access/htup_details.h"
 #include "access/multixact.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "catalog/catalog.h"
 #include "catalog/indexing.h"
 #include "catalog/namespace.h"
diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index 6d5f65b8bd..e5f7765d55 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -17,6 +17,8 @@
 #include "access/htup_details.h"
 #include "access/multixact.h"
 #include "access/transam.h"
+#include "access/xlog.h"
+#include "access/xloginsert.h"
 #include "access/xlogutils.h"
 #include "catalog/dependency.h"
 #include "catalog/namespace.h"
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index ecdff1e5e3..714a9f1ee7 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -21,6 +21,7 @@
 #include "access/relscan.h"
 #include "access/sysattr.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "catalog/catalog.h"
 #include "catalog/dependency.h"
 #include "catalog/heap.h"
diff --git a/src/backend/commands/tablespace.c b/src/backend/commands/tablespace.c
index 28e69a5551..378e355adc 100644
--- a/src/backend/commands/tablespace.c
+++ b/src/backend/commands/tablespace.c
@@ -56,6 +56,8 @@
 #include "access/htup_details.h"
 #include "access/sysattr.h"
 #include "access/xact.h"
+#include "access/xlog.h"
+#include "access/xloginsert.h"
 #include "catalog/catalog.h"
 #include "catalog/dependency.h"
 #include "catalog/indexing.h"
diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c
index 3778d9d425..8dad8c269c 100644
--- a/src/backend/commands/vacuumlazy.c
+++ b/src/backend/commands/vacuumlazy.c
@@ -44,6 +44,7 @@
 #include "access/multixact.h"
 #include "access/transam.h"
 #include "access/visibilitymap.h"
+#include "access/xlog.h"
 #include "catalog/catalog.h"
 #include "catalog/storage.h"
 #include "commands/dbcommands.h"
diff --git a/src/backend/commands/variable.c b/src/backend/commands/variable.c
index 40a991653d..6ce8daeb95 100644
--- a/src/backend/commands/variable.c
+++ b/src/backend/commands/variable.c
@@ -20,6 +20,7 @@
 
 #include "access/htup_details.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "catalog/pg_authid.h"
 #include "commands/variable.h"
 #include "miscadmin.h"
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 57067ef57a..cbfe05e2b5 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -33,6 +33,7 @@
 #include <sys/file.h>
 #include <unistd.h>
 
+#include "access/xlog.h"
 #include "catalog/catalog.h"
 #include "catalog/storage.h"
 #include "executor/instrument.h"
diff --git a/src/backend/storage/file/fd.c b/src/backend/storage/file/fd.c
index 1f69c9e03c..a11fa6cbdf 100644
--- a/src/backend/storage/file/fd.c
+++ b/src/backend/storage/file/fd.c
@@ -69,6 +69,7 @@
 
 #include "miscadmin.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "catalog/catalog.h"
 #include "catalog/pg_tablespace.h"
 #include "pgstat.h"
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index ea82882aa6..d953545138 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -48,8 +48,9 @@
 #include "access/clog.h"
 #include "access/subtrans.h"
 #include "access/transam.h"
-#include "access/xact.h"
 #include "access/twophase.h"
+#include "access/xact.h"
+#include "access/xlog.h"
 #include "catalog/catalog.h"
 #include "miscadmin.h"
 #include "storage/proc.h"
diff --git a/src/backend/storage/ipc/standby.c b/src/backend/storage/ipc/standby.c
index 1c327fd45c..8c3720bc73 100644
--- a/src/backend/storage/ipc/standby.c
+++ b/src/backend/storage/ipc/standby.c
@@ -20,6 +20,7 @@
 #include "access/twophase.h"
 #include "access/xact.h"
 #include "access/xlog.h"
+#include "access/xloginsert.h"
 #include "miscadmin.h"
 #include "storage/bufmgr.h"
 #include "storage/lmgr.h"
diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
index 723051efb5..cbe9574756 100644
--- a/src/backend/storage/lmgr/lock.c
+++ b/src/backend/storage/lmgr/lock.c
@@ -35,6 +35,7 @@
 #include "access/transam.h"
 #include "access/twophase.h"
 #include "access/twophase_rmgr.h"
+#include "access/xlog.h"
 #include "miscadmin.h"
 #include "pg_trace.h"
 #include "pgstat.h"
diff --git a/src/backend/storage/lmgr/predicate.c b/src/backend/storage/lmgr/predicate.c
index 7c8d53e6a5..f1261181c9 100644
--- a/src/backend/storage/lmgr/predicate.c
+++ b/src/backend/storage/lmgr/predicate.c
@@ -190,6 +190,7 @@
 #include "access/twophase.h"
 #include "access/twophase_rmgr.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "miscadmin.h"
 #include "storage/bufmgr.h"
 #include "storage/predicate.h"
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 4a2a339cf2..422911cde0 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -20,6 +20,7 @@
 #include "access/reloptions.h"
 #include "access/twophase.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "catalog/catalog.h"
 #include "catalog/namespace.h"
 #include "catalog/toasting.h"
diff --git a/src/backend/utils/adt/txid.c b/src/backend/utils/adt/txid.c
index 7969a3353c..1a2cc1d928 100644
--- a/src/backend/utils/adt/txid.c
+++ b/src/backend/utils/adt/txid.c
@@ -23,6 +23,7 @@
 
 #include "access/transam.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "funcapi.h"
 #include "miscadmin.h"
 #include "libpq/pqformat.h"
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index c8137798f2..e8ed9995ff 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -36,6 +36,7 @@
 #include "access/sysattr.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "catalog/catalog.h"
 #include "catalog/index.h"
 #include "catalog/indexing.h"
diff --git a/src/backend/utils/cache/relmapper.c b/src/backend/utils/cache/relmapper.c
index b6b1330877..d1f64e58c8 100644
--- a/src/backend/utils/cache/relmapper.c
+++ b/src/backend/utils/cache/relmapper.c
@@ -44,6 +44,8 @@
 #include <unistd.h>
 
 #include "access/xact.h"
+#include "access/xlog.h"
+#include "access/xloginsert.h"
 #include "catalog/catalog.h"
 #include "catalog/pg_tablespace.h"
 #include "catalog/storage.h"
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 6a6a4453cd..c34803437b 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -23,6 +23,7 @@
 #include "access/htup_details.h"
 #include "access/sysattr.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "catalog/catalog.h"
 #include "catalog/indexing.h"
 #include "catalog/namespace.h"
diff --git a/src/backend/utils/sort/tuplestore.c b/src/backend/utils/sort/tuplestore.c
index 1d6fe86994..a69aae3b9e 100644
--- a/src/backend/utils/sort/tuplestore.c
+++ b/src/backend/utils/sort/tuplestore.c
@@ -54,6 +54,8 @@
 
 #include "postgres.h"
 
+#include <limits.h>
+
 #include "access/htup_details.h"
 #include "commands/tablespace.h"
 #include "executor/executor.h"
diff --git a/src/backend/utils/time/tqual.c b/src/backend/utils/time/tqual.c
index 5c3f5adb4a..a2c4989428 100644
--- a/src/backend/utils/time/tqual.c
+++ b/src/backend/utils/time/tqual.c
@@ -60,6 +60,7 @@
 #include "access/subtrans.h"
 #include "access/transam.h"
 #include "access/xact.h"
+#include "access/xlog.h"
 #include "storage/bufmgr.h"
 #include "storage/procarray.h"
 #include "utils/builtins.h"
diff --git a/src/bin/pg_resetxlog/pg_resetxlog.c b/src/bin/pg_resetxlog/pg_resetxlog.c
index e224e67ad6..2ba9946982 100644
--- a/src/bin/pg_resetxlog/pg_resetxlog.c
+++ b/src/bin/pg_resetxlog/pg_resetxlog.c
@@ -48,6 +48,7 @@
 #include "access/transam.h"
 #include "access/tuptoaster.h"
 #include "access/multixact.h"
+#include "access/xlog.h"
 #include "access/xlog_internal.h"
 #include "catalog/catversion.h"
 #include "catalog/pg_control.h"
diff --git a/src/include/access/clog.h b/src/include/access/clog.h
index 8562631b54..04ac4ba311 100644
--- a/src/include/access/clog.h
+++ b/src/include/access/clog.h
@@ -11,7 +11,8 @@
 #ifndef CLOG_H
 #define CLOG_H
 
-#include "access/xlog.h"
+#include "access/xlogrecord.h"
+#include "lib/stringinfo.h"
 
 /*
  * Possible transaction statuses --- note that all-zeroes is the initial
diff --git a/src/include/access/gin.h b/src/include/access/gin.h
index 0ebecb4140..80826b843b 100644
--- a/src/include/access/gin.h
+++ b/src/include/access/gin.h
@@ -10,7 +10,8 @@
 #ifndef GIN_H
 #define GIN_H
 
-#include "access/xlog.h"
+#include "access/xlogrecord.h"
+#include "lib/stringinfo.h"
 #include "storage/block.h"
 #include "utils/relcache.h"
 
diff --git a/src/include/access/gin_private.h b/src/include/access/gin_private.h
index ab3afb812e..6a09dc990e 100644
--- a/src/include/access/gin_private.h
+++ b/src/include/access/gin_private.h
@@ -13,6 +13,7 @@
 #include "access/genam.h"
 #include "access/gin.h"
 #include "access/itup.h"
+#include "access/xloginsert.h"
 #include "fmgr.h"
 #include "storage/bufmgr.h"
 #include "utils/rbtree.h"
diff --git a/src/include/access/gist_private.h b/src/include/access/gist_private.h
index 879f11351b..21daf3b2b6 100644
--- a/src/include/access/gist_private.h
+++ b/src/include/access/gist_private.h
@@ -16,6 +16,7 @@
 
 #include "access/gist.h"
 #include "access/itup.h"
+#include "access/xlogrecord.h"
 #include "fmgr.h"
 #include "storage/bufmgr.h"
 #include "storage/buffile.h"
diff --git a/src/include/access/hash.h b/src/include/access/hash.h
index a81b9de0e6..c175a5c182 100644
--- a/src/include/access/hash.h
+++ b/src/include/access/hash.h
@@ -20,8 +20,9 @@
 #include "access/genam.h"
 #include "access/itup.h"
 #include "access/sdir.h"
-#include "access/xlog.h"
+#include "access/xlogrecord.h"
 #include "fmgr.h"
+#include "lib/stringinfo.h"
 #include "storage/bufmgr.h"
 #include "storage/lock.h"
 #include "utils/relcache.h"
diff --git a/src/include/access/heapam_xlog.h b/src/include/access/heapam_xlog.h
index 5ac98a5baa..1d64264b01 100644
--- a/src/include/access/heapam_xlog.h
+++ b/src/include/access/heapam_xlog.h
@@ -15,7 +15,9 @@
 #define HEAPAM_XLOG_H
 
 #include "access/htup.h"
-#include "access/xlog.h"
+#include "access/xlogrecord.h"
+#include "lib/stringinfo.h"
+#include "storage/buf.h"
 #include "storage/bufpage.h"
 #include "storage/relfilenode.h"
 #include "utils/relcache.h"
diff --git a/src/include/access/multixact.h b/src/include/access/multixact.h
index b331447ade..43d737505d 100644
--- a/src/include/access/multixact.h
+++ b/src/include/access/multixact.h
@@ -11,7 +11,8 @@
 #ifndef MULTIXACT_H
 #define MULTIXACT_H
 
-#include "access/xlog.h"
+#include "access/xlogrecord.h"
+#include "lib/stringinfo.h"
 
 
 /*
diff --git a/src/include/access/nbtree.h b/src/include/access/nbtree.h
index 90fd6d0056..c8bb3f5d66 100644
--- a/src/include/access/nbtree.h
+++ b/src/include/access/nbtree.h
@@ -17,9 +17,10 @@
 #include "access/genam.h"
 #include "access/itup.h"
 #include "access/sdir.h"
-#include "access/xlog.h"
-#include "access/xlogutils.h"
+#include "access/xlogrecord.h"
 #include "catalog/pg_index.h"
+#include "lib/stringinfo.h"
+#include "storage/bufmgr.h"
 
 /* There's room for a 16-bit vacuum cycle ID in BTPageOpaqueData */
 typedef uint16 BTCycleId;
diff --git a/src/include/access/spgist.h b/src/include/access/spgist.h
index f218a83224..ccf1ed7786 100644
--- a/src/include/access/spgist.h
+++ b/src/include/access/spgist.h
@@ -15,8 +15,9 @@
 #define SPGIST_H
 
 #include "access/skey.h"
-#include "access/xlog.h"
+#include "access/xlogrecord.h"
 #include "fmgr.h"
+#include "lib/stringinfo.h"
 
 
 /* reloption parameters */
diff --git a/src/include/access/spgist_private.h b/src/include/access/spgist_private.h
index d092029d8a..3330644651 100644
--- a/src/include/access/spgist_private.h
+++ b/src/include/access/spgist_private.h
@@ -17,6 +17,7 @@
 #include "access/itup.h"
 #include "access/spgist.h"
 #include "nodes/tidbitmap.h"
+#include "storage/buf.h"
 #include "storage/relfilenode.h"
 #include "utils/relcache.h"
 
diff --git a/src/include/access/xact.h b/src/include/access/xact.h
index 45376b4792..11a51b2685 100644
--- a/src/include/access/xact.h
+++ b/src/include/access/xact.h
@@ -14,9 +14,11 @@
 #ifndef XACT_H
 #define XACT_H
 
-#include "access/xlog.h"
+#include "access/xlogrecord.h"
+#include "lib/stringinfo.h"
 #include "nodes/pg_list.h"
 #include "storage/relfilenode.h"
+#include "utils/datetime.h"
 
 
 /*
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 0ae110f18b..6f8b5f46e1 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -13,67 +13,11 @@
 
 #include "access/rmgr.h"
 #include "access/xlogdefs.h"
+#include "access/xloginsert.h"
+#include "access/xlogrecord.h"
 #include "datatype/timestamp.h"
 #include "lib/stringinfo.h"
-#include "storage/block.h"
-#include "storage/buf.h"
-#include "storage/relfilenode.h"
-#include "utils/pg_crc.h"
 
-/*
- * The overall layout of an XLOG record is:
- *		Fixed-size header (XLogRecord struct)
- *		rmgr-specific data
- *		BkpBlock
- *		backup block data
- *		BkpBlock
- *		backup block data
- *		...
- *
- * where there can be zero to four backup blocks (as signaled by xl_info flag
- * bits).  XLogRecord structs always start on MAXALIGN boundaries in the WAL
- * files, and we round up SizeOfXLogRecord so that the rmgr data is also
- * guaranteed to begin on a MAXALIGN boundary.  However, no padding is added
- * to align BkpBlock structs or backup block data.
- *
- * NOTE: xl_len counts only the rmgr data, not the XLogRecord header,
- * and also not any backup blocks.  xl_tot_len counts everything.  Neither
- * length field is rounded up to an alignment boundary.
- */
-typedef struct XLogRecord
-{
-	uint32		xl_tot_len;		/* total len of entire record */
-	TransactionId xl_xid;		/* xact id */
-	uint32		xl_len;			/* total len of rmgr data */
-	uint8		xl_info;		/* flag bits, see below */
-	RmgrId		xl_rmid;		/* resource manager for this record */
-	/* 2 bytes of padding here, initialize to zero */
-	XLogRecPtr	xl_prev;		/* ptr to previous record in log */
-	pg_crc32	xl_crc;			/* CRC for this record */
-
-	/* If MAXALIGN==8, there are 4 wasted bytes here */
-
-	/* ACTUAL LOG DATA FOLLOWS AT END OF STRUCT */
-
-} XLogRecord;
-
-#define SizeOfXLogRecord	MAXALIGN(sizeof(XLogRecord))
-
-#define XLogRecGetData(record)	((char*) (record) + SizeOfXLogRecord)
-
-/*
- * XLOG uses only low 4 bits of xl_info.  High 4 bits may be used by rmgr.
- */
-#define XLR_INFO_MASK			0x0F
-
-/*
- * If we backed up any disk blocks with the XLOG record, we use flag bits in
- * xl_info to signal it.  We support backup of up to 4 disk blocks per XLOG
- * record.
- */
-#define XLR_BKP_BLOCK_MASK		0x0F	/* all info bits used for bkp blocks */
-#define XLR_MAX_BKP_BLOCKS		4
-#define XLR_BKP_BLOCK(iblk)		(0x08 >> (iblk))		/* iblk in 0..3 */
 
 /* Sync methods */
 #define SYNC_METHOD_FSYNC		0
@@ -83,45 +27,6 @@ typedef struct XLogRecord
 #define SYNC_METHOD_OPEN_DSYNC	4		/* for O_DSYNC */
 extern int	sync_method;
 
-/*
- * The rmgr data to be written by XLogInsert() is defined by a chain of
- * one or more XLogRecData structs.  (Multiple structs would be used when
- * parts of the source data aren't physically adjacent in memory, or when
- * multiple associated buffers need to be specified.)
- *
- * If buffer is valid then XLOG will check if buffer must be backed up
- * (ie, whether this is first change of that page since last checkpoint).
- * If so, the whole page contents are attached to the XLOG record, and XLOG
- * sets XLR_BKP_BLOCK(N) bit in xl_info.  Note that the buffer must be pinned
- * and exclusive-locked by the caller, so that it won't change under us.
- * NB: when the buffer is backed up, we DO NOT insert the data pointed to by
- * this XLogRecData struct into the XLOG record, since we assume it's present
- * in the buffer.  Therefore, rmgr redo routines MUST pay attention to
- * XLR_BKP_BLOCK(N) to know what is actually stored in the XLOG record.
- * The N'th XLR_BKP_BLOCK bit corresponds to the N'th distinct buffer
- * value (ignoring InvalidBuffer) appearing in the rdata chain.
- *
- * When buffer is valid, caller must set buffer_std to indicate whether the
- * page uses standard pd_lower/pd_upper header fields.  If this is true, then
- * XLOG is allowed to omit the free space between pd_lower and pd_upper from
- * the backed-up page image.  Note that even when buffer_std is false, the
- * page MUST have an LSN field as its first eight bytes!
- *
- * Note: data can be NULL to indicate no rmgr data associated with this chain
- * entry.  This can be sensible (ie, not a wasted entry) if buffer is valid.
- * The implication is that the buffer has been changed by the operation being
- * logged, and so may need to be backed up, but the change can be redone using
- * only information already present elsewhere in the XLOG entry.
- */
-typedef struct XLogRecData
-{
-	char	   *data;			/* start of rmgr data to include */
-	uint32		len;			/* length of rmgr data to include */
-	Buffer		buffer;			/* buffer associated with data, if any */
-	bool		buffer_std;		/* buffer has standard pd_lower/pd_upper */
-	struct XLogRecData *next;	/* next struct in chain, or NULL */
-} XLogRecData;
-
 extern PGDLLIMPORT TimeLineID ThisTimeLineID;	/* current TLI */
 
 /*
@@ -281,28 +186,18 @@ typedef struct CheckpointStatsData
 
 extern CheckpointStatsData CheckpointStats;
 
-extern XLogRecPtr XLogInsert(RmgrId rmid, uint8 info, XLogRecData *rdata);
-extern bool XLogCheckBufferNeedsBackup(Buffer buffer);
+extern XLogRecPtr XLogInsertRecord(XLogRecData *rdata, XLogRecPtr fpw_lsn);
 extern void XLogFlush(XLogRecPtr RecPtr);
 extern bool XLogBackgroundFlush(void);
 extern bool XLogNeedsFlush(XLogRecPtr RecPtr);
 extern int	XLogFileInit(XLogSegNo segno, bool *use_existent, bool use_lock);
 extern int	XLogFileOpen(XLogSegNo segno);
 
-extern XLogRecPtr log_newpage(RelFileNode *rnode, ForkNumber forkNum,
-			BlockNumber blk, char *page, bool page_std);
-extern XLogRecPtr log_newpage_buffer(Buffer buffer, bool page_std);
-extern XLogRecPtr XLogSaveBufferForHint(Buffer buffer, bool buffer_std);
-
 extern void CheckXLogRemoved(XLogSegNo segno, TimeLineID tli);
 extern XLogSegNo XLogGetLastRemovedSegno(void);
 extern void XLogSetAsyncXactLSN(XLogRecPtr record);
 extern void XLogSetReplicationSlotMinimumLSN(XLogRecPtr lsn);
 
-extern Buffer RestoreBackupBlock(XLogRecPtr lsn, XLogRecord *record,
-				   int block_index,
-				   bool get_cleanup_lock, bool keep_buffer);
-
 extern void xlog_redo(XLogRecPtr lsn, XLogRecord *record);
 extern void xlog_desc(StringInfo buf, XLogRecord *record);
 extern const char *xlog_identify(uint8 info);
@@ -338,6 +233,7 @@ extern bool CreateRestartPoint(int flags);
 extern void XLogPutNextOid(Oid nextOid);
 extern XLogRecPtr XLogRestorePoint(const char *rpName);
 extern void UpdateFullPageWrites(void);
+extern void GetFullPageWriteInfo(XLogRecPtr *RedoRecPtr_p, bool *doPageWrites_p);
 extern XLogRecPtr GetRedoRecPtr(void);
 extern XLogRecPtr GetInsertRecPtr(void);
 extern XLogRecPtr GetFlushRecPtr(void);
diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h
index eaa1f9540e..19b2ef8d90 100644
--- a/src/include/access/xlog_internal.h
+++ b/src/include/access/xlog_internal.h
@@ -6,7 +6,7 @@
  * NOTE: this file is intended to contain declarations useful for
  * manipulating the XLOG files directly, but it is not supposed to be
  * needed by rmgr routines (redo support for individual record types).
- * So the XLogRecord typedef and associated stuff appear in xlog.h.
+ * So the XLogRecord typedef and associated stuff appear in xlogrecord.h.
  *
  * Note: This file must be includable in both frontend and backend contexts,
  * to allow stand-alone tools like pg_receivexlog to deal with WAL files.
@@ -20,6 +20,7 @@
 #define XLOG_INTERNAL_H
 
 #include "access/xlogdefs.h"
+#include "access/xlogrecord.h"
 #include "datatype/timestamp.h"
 #include "lib/stringinfo.h"
 #include "pgtime.h"
@@ -27,31 +28,6 @@
 #include "storage/relfilenode.h"
 
 
-/*
- * Header info for a backup block appended to an XLOG record.
- *
- * As a trivial form of data compression, the XLOG code is aware that
- * PG data pages usually contain an unused "hole" in the middle, which
- * contains only zero bytes.  If hole_length > 0 then we have removed
- * such a "hole" from the stored data (and it's not counted in the
- * XLOG record's CRC, either).  Hence, the amount of block data actually
- * present following the BkpBlock struct is BLCKSZ - hole_length bytes.
- *
- * Note that we don't attempt to align either the BkpBlock struct or the
- * block's data.  So, the struct must be copied to aligned local storage
- * before use.
- */
-typedef struct BkpBlock
-{
-	RelFileNode node;			/* relation containing block */
-	ForkNumber	fork;			/* fork within the relation */
-	BlockNumber block;			/* block number */
-	uint16		hole_offset;	/* number of bytes before "hole" */
-	uint16		hole_length;	/* number of bytes in "hole" */
-
-	/* ACTUAL BLOCK DATA FOLLOWS AT END OF STRUCT */
-} BkpBlock;
-
 /*
  * Each page of XLOG file has a header like this:
  */
@@ -227,12 +203,6 @@ typedef struct xl_end_of_recovery
 	TimeLineID	PrevTimeLineID; /* previous TLI we forked off from */
 } xl_end_of_recovery;
 
-/*
- * XLogRecord is defined in xlog.h, but we avoid #including that to keep
- * this file includable in stand-alone programs.
- */
-struct XLogRecord;
-
 /*
  * Method table for resource managers.
  *
@@ -249,8 +219,8 @@ struct XLogRecord;
 typedef struct RmgrData
 {
 	const char *rm_name;
-	void		(*rm_redo) (XLogRecPtr lsn, struct XLogRecord *rptr);
-	void		(*rm_desc) (StringInfo buf, struct XLogRecord *rptr);
+	void		(*rm_redo) (XLogRecPtr lsn, XLogRecord *rptr);
+	void		(*rm_desc) (StringInfo buf, XLogRecord *rptr);
 	const char *(*rm_identify) (uint8 info);
 	void		(*rm_startup) (void);
 	void		(*rm_cleanup) (void);
diff --git a/src/include/access/xloginsert.h b/src/include/access/xloginsert.h
new file mode 100644
index 0000000000..30c2e84cbc
--- /dev/null
+++ b/src/include/access/xloginsert.h
@@ -0,0 +1,66 @@
+/*
+ * xloginsert.h
+ *
+ * Functions for generating WAL records
+ *
+ * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/access/xloginsert.h
+ */
+#ifndef XLOGINSERT_H
+#define XLOGINSERT_H
+
+#include "access/rmgr.h"
+#include "access/xlogdefs.h"
+#include "storage/block.h"
+#include "storage/buf.h"
+#include "storage/relfilenode.h"
+
+/*
+ * The rmgr data to be written by XLogInsert() is defined by a chain of
+ * one or more XLogRecData structs.  (Multiple structs would be used when
+ * parts of the source data aren't physically adjacent in memory, or when
+ * multiple associated buffers need to be specified.)
+ *
+ * If buffer is valid then XLOG will check if buffer must be backed up
+ * (ie, whether this is first change of that page since last checkpoint).
+ * If so, the whole page contents are attached to the XLOG record, and XLOG
+ * sets XLR_BKP_BLOCK(N) bit in xl_info.  Note that the buffer must be pinned
+ * and exclusive-locked by the caller, so that it won't change under us.
+ * NB: when the buffer is backed up, we DO NOT insert the data pointed to by
+ * this XLogRecData struct into the XLOG record, since we assume it's present
+ * in the buffer.  Therefore, rmgr redo routines MUST pay attention to
+ * XLR_BKP_BLOCK(N) to know what is actually stored in the XLOG record.
+ * The N'th XLR_BKP_BLOCK bit corresponds to the N'th distinct buffer
+ * value (ignoring InvalidBuffer) appearing in the rdata chain.
+ *
+ * When buffer is valid, caller must set buffer_std to indicate whether the
+ * page uses standard pd_lower/pd_upper header fields.  If this is true, then
+ * XLOG is allowed to omit the free space between pd_lower and pd_upper from
+ * the backed-up page image.  Note that even when buffer_std is false, the
+ * page MUST have an LSN field as its first eight bytes!
+ *
+ * Note: data can be NULL to indicate no rmgr data associated with this chain
+ * entry.  This can be sensible (ie, not a wasted entry) if buffer is valid.
+ * The implication is that the buffer has been changed by the operation being
+ * logged, and so may need to be backed up, but the change can be redone using
+ * only information already present elsewhere in the XLOG entry.
+ */
+typedef struct XLogRecData
+{
+	char	   *data;			/* start of rmgr data to include */
+	uint32		len;			/* length of rmgr data to include */
+	Buffer		buffer;			/* buffer associated with data, if any */
+	bool		buffer_std;		/* buffer has standard pd_lower/pd_upper */
+	struct XLogRecData *next;	/* next struct in chain, or NULL */
+} XLogRecData;
+
+extern XLogRecPtr XLogInsert(RmgrId rmid, uint8 info, XLogRecData *rdata);
+extern XLogRecPtr log_newpage(RelFileNode *rnode, ForkNumber forkNum,
+			BlockNumber blk, char *page, bool page_std);
+extern XLogRecPtr log_newpage_buffer(Buffer buffer, bool page_std);
+extern XLogRecPtr XLogSaveBufferForHint(Buffer buffer, bool buffer_std);
+extern bool XLogCheckBufferNeedsBackup(Buffer buffer);
+
+#endif   /* XLOGINSERT_H */
diff --git a/src/include/access/xlogrecord.h b/src/include/access/xlogrecord.h
new file mode 100644
index 0000000000..ab0fb1c500
--- /dev/null
+++ b/src/include/access/xlogrecord.h
@@ -0,0 +1,100 @@
+/*
+ * xlogrecord.h
+ *
+ * Definitions for the WAL record format.
+ *
+ * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/access/xlogrecord.h
+ */
+#ifndef XLOGRECORD_H
+#define XLOGRECORD_H
+
+#include "access/rmgr.h"
+#include "access/xlogdefs.h"
+#include "storage/block.h"
+#include "storage/relfilenode.h"
+#include "utils/pg_crc.h"
+
+/*
+ * The overall layout of an XLOG record is:
+ *		Fixed-size header (XLogRecord struct)
+ *		rmgr-specific data
+ *		BkpBlock
+ *		backup block data
+ *		BkpBlock
+ *		backup block data
+ *		...
+ *
+ * where there can be zero to four backup blocks (as signaled by xl_info flag
+ * bits).  XLogRecord structs always start on MAXALIGN boundaries in the WAL
+ * files, and we round up SizeOfXLogRecord so that the rmgr data is also
+ * guaranteed to begin on a MAXALIGN boundary.  However, no padding is added
+ * to align BkpBlock structs or backup block data.
+ *
+ * NOTE: xl_len counts only the rmgr data, not the XLogRecord header,
+ * and also not any backup blocks.  xl_tot_len counts everything.  Neither
+ * length field is rounded up to an alignment boundary.
+ */
+typedef struct XLogRecord
+{
+	uint32		xl_tot_len;		/* total len of entire record */
+	TransactionId xl_xid;		/* xact id */
+	uint32		xl_len;			/* total len of rmgr data */
+	uint8		xl_info;		/* flag bits, see below */
+	RmgrId		xl_rmid;		/* resource manager for this record */
+	/* 2 bytes of padding here, initialize to zero */
+	XLogRecPtr	xl_prev;		/* ptr to previous record in log */
+	pg_crc32	xl_crc;			/* CRC for this record */
+
+	/* If MAXALIGN==8, there are 4 wasted bytes here */
+
+	/* ACTUAL LOG DATA FOLLOWS AT END OF STRUCT */
+
+} XLogRecord;
+
+#define SizeOfXLogRecord	MAXALIGN(sizeof(XLogRecord))
+
+#define XLogRecGetData(record)	((char*) (record) + SizeOfXLogRecord)
+
+/*
+ * XLOG uses only low 4 bits of xl_info.  High 4 bits may be used by rmgr.
+ */
+#define XLR_INFO_MASK			0x0F
+
+/*
+ * If we backed up any disk blocks with the XLOG record, we use flag bits in
+ * xl_info to signal it.  We support backup of up to 4 disk blocks per XLOG
+ * record.
+ */
+#define XLR_BKP_BLOCK_MASK		0x0F	/* all info bits used for bkp blocks */
+#define XLR_MAX_BKP_BLOCKS		4
+#define XLR_BKP_BLOCK(iblk)		(0x08 >> (iblk))		/* iblk in 0..3 */
+
+/*
+ * Header info for a backup block appended to an XLOG record.
+ *
+ * As a trivial form of data compression, the XLOG code is aware that
+ * PG data pages usually contain an unused "hole" in the middle, which
+ * contains only zero bytes.  If hole_length > 0 then we have removed
+ * such a "hole" from the stored data (and it's not counted in the
+ * XLOG record's CRC, either).  Hence, the amount of block data actually
+ * present following the BkpBlock struct is BLCKSZ - hole_length bytes.
+ *
+ * Note that we don't attempt to align either the BkpBlock struct or the
+ * block's data.  So, the struct must be copied to aligned local storage
+ * before use.
+ */
+typedef struct BkpBlock
+{
+	RelFileNode node;			/* relation containing block */
+	ForkNumber	fork;			/* fork within the relation */
+	BlockNumber block;			/* block number */
+	uint16		hole_offset;	/* number of bytes before "hole" */
+	uint16		hole_length;	/* number of bytes in "hole" */
+
+	/* ACTUAL BLOCK DATA FOLLOWS AT END OF STRUCT */
+} BkpBlock;
+
+#endif   /* XLOGRECORD_H */
diff --git a/src/include/access/xlogutils.h b/src/include/access/xlogutils.h
index ad579083ab..8d90696723 100644
--- a/src/include/access/xlogutils.h
+++ b/src/include/access/xlogutils.h
@@ -11,7 +11,7 @@
 #ifndef XLOG_UTILS_H
 #define XLOG_UTILS_H
 
-#include "access/xlog.h"
+#include "access/xlogrecord.h"
 #include "storage/bufmgr.h"
 
 
@@ -47,6 +47,12 @@ extern Buffer XLogReadBuffer(RelFileNode rnode, BlockNumber blkno, bool init);
 extern Buffer XLogReadBufferExtended(RelFileNode rnode, ForkNumber forknum,
 					   BlockNumber blkno, ReadBufferMode mode);
 
+extern Buffer RestoreBackupBlock(XLogRecPtr lsn, XLogRecord *record,
+				   int block_index,
+				   bool get_cleanup_lock, bool keep_buffer);
+extern Buffer RestoreBackupBlockContents(XLogRecPtr lsn, BkpBlock bkpb,
+						 char *blk, bool get_cleanup_lock, bool keep_buffer);
+
 extern Relation CreateFakeRelcacheEntry(RelFileNode rnode);
 extern void FreeFakeRelcacheEntry(Relation fakerel);
 
diff --git a/src/include/catalog/storage_xlog.h b/src/include/catalog/storage_xlog.h
index 5fc7235828..6c687e3a82 100644
--- a/src/include/catalog/storage_xlog.h
+++ b/src/include/catalog/storage_xlog.h
@@ -14,7 +14,8 @@
 #ifndef STORAGE_XLOG_H
 #define STORAGE_XLOG_H
 
-#include "access/xlog.h"
+#include "access/xlogrecord.h"
+#include "lib/stringinfo.h"
 #include "storage/block.h"
 #include "storage/relfilenode.h"
 
diff --git a/src/include/commands/dbcommands.h b/src/include/commands/dbcommands.h
index 811713fb83..b79d9fc864 100644
--- a/src/include/commands/dbcommands.h
+++ b/src/include/commands/dbcommands.h
@@ -14,7 +14,8 @@
 #ifndef DBCOMMANDS_H
 #define DBCOMMANDS_H
 
-#include "access/xlog.h"
+#include "access/xlogrecord.h"
+#include "lib/stringinfo.h"
 #include "nodes/parsenodes.h"
 
 /* XLOG stuff */
diff --git a/src/include/commands/sequence.h b/src/include/commands/sequence.h
index 914d155c9f..7cbe6f9a81 100644
--- a/src/include/commands/sequence.h
+++ b/src/include/commands/sequence.h
@@ -13,8 +13,9 @@
 #ifndef SEQUENCE_H
 #define SEQUENCE_H
 
-#include "access/xlog.h"
+#include "access/xlogrecord.h"
 #include "fmgr.h"
+#include "lib/stringinfo.h"
 #include "nodes/parsenodes.h"
 #include "storage/relfilenode.h"
 
diff --git a/src/include/commands/tablespace.h b/src/include/commands/tablespace.h
index 0f16f40e3d..afd9e05cb7 100644
--- a/src/include/commands/tablespace.h
+++ b/src/include/commands/tablespace.h
@@ -14,7 +14,8 @@
 #ifndef TABLESPACE_H
 #define TABLESPACE_H
 
-#include "access/xlog.h"
+#include "access/xlogrecord.h"
+#include "lib/stringinfo.h"
 #include "nodes/parsenodes.h"
 
 /* XLOG stuff */
diff --git a/src/include/replication/decode.h b/src/include/replication/decode.h
index d9e30776af..e4185287a1 100644
--- a/src/include/replication/decode.h
+++ b/src/include/replication/decode.h
@@ -10,6 +10,7 @@
 #define DECODE_H
 
 #include "access/xlogreader.h"
+#include "access/xlogrecord.h"
 #include "replication/reorderbuffer.h"
 #include "replication/logical.h"
 
diff --git a/src/include/storage/standby.h b/src/include/storage/standby.h
index 1c63af521f..c89989fd20 100644
--- a/src/include/storage/standby.h
+++ b/src/include/storage/standby.h
@@ -14,7 +14,8 @@
 #ifndef STANDBY_H
 #define STANDBY_H
 
-#include "access/xlog.h"
+#include "access/xlogrecord.h"
+#include "lib/stringinfo.h"
 #include "storage/lock.h"
 #include "storage/procsignal.h"
 #include "storage/relfilenode.h"
diff --git a/src/include/utils/relmapper.h b/src/include/utils/relmapper.h
index 37937ddab8..bd5836b0d9 100644
--- a/src/include/utils/relmapper.h
+++ b/src/include/utils/relmapper.h
@@ -14,7 +14,8 @@
 #ifndef RELMAPPER_H
 #define RELMAPPER_H
 
-#include "access/xlog.h"
+#include "access/xlogrecord.h"
+#include "lib/stringinfo.h"
 
 /* ----------------
  *		relmap-related XLOG entries