*** a/src/backend/access/transam/xlogutils.c
--- b/src/backend/access/transam/xlogutils.c
***************
*** 293,300 **** Buffer
  XLogReadBufferExtended(RelFileNode rnode, ForkNumber forknum,
  					   BlockNumber blkno, ReadBufferMode mode)
  {
- 	BlockNumber lastblock;
  	Buffer		buffer;
  	SMgrRelation smgr;
  
  	Assert(blkno != P_NEW);
--- 293,300 ----
  XLogReadBufferExtended(RelFileNode rnode, ForkNumber forknum,
  					   BlockNumber blkno, ReadBufferMode mode)
  {
  	Buffer		buffer;
+ 	Page 		page;
  	SMgrRelation smgr;
  
  	Assert(blkno != P_NEW);
***************
*** 312,353 **** XLogReadBufferExtended(RelFileNode rnode, ForkNumber forknum,
  	 */
  	smgrcreate(smgr, forknum, true);
  
! 	lastblock = smgrnblocks(smgr, forknum);
! 
! 	if (blkno < lastblock)
! 	{
! 		/* page exists in file */
! 		buffer = ReadBufferWithoutRelcache(rnode, forknum, blkno,
! 										   mode, NULL);
! 	}
! 	else
  	{
  		/* hm, page doesn't exist in file */
! 		if (mode == RBM_NORMAL)
  		{
  			log_invalid_page(rnode, forknum, blkno, false);
  			return InvalidBuffer;
  		}
- 		/* OK to extend the file */
- 		/* we do this in recovery only - no rel-extension lock needed */
- 		Assert(InRecovery);
- 		buffer = InvalidBuffer;
- 		while (blkno >= lastblock)
- 		{
- 			if (buffer != InvalidBuffer)
- 				ReleaseBuffer(buffer);
- 			buffer = ReadBufferWithoutRelcache(rnode, forknum,
- 											   P_NEW, mode, NULL);
- 			lastblock++;
- 		}
- 		Assert(BufferGetBlockNumber(buffer) == blkno);
- 	}
  
! 	if (mode == RBM_NORMAL)
! 	{
! 		/* check that page has been initialized */
! 		Page		page = (Page) BufferGetPage(buffer);
  
  		/*
  		 * We assume that PageIsNew is safe without a lock. During recovery,
  		 * there should be no other backends that could modify the buffer at
--- 312,332 ----
  	 */
  	smgrcreate(smgr, forknum, true);
  
! 	if (mode == RBM_NORMAL)
  	{
  		/* hm, page doesn't exist in file */
! 		if (blkno >= smgrnblocks(smgr, forknum))
  		{
  			log_invalid_page(rnode, forknum, blkno, false);
  			return InvalidBuffer;
  		}
  
! 		buffer = ReadBufferWithoutRelcache(rnode, forknum, blkno,
! 										   mode, NULL);
  
+ 		/* check that page has been initialized */
+ 		page = (Page) BufferGetPage(buffer);
+ 		
  		/*
  		 * We assume that PageIsNew is safe without a lock. During recovery,
  		 * there should be no other backends that could modify the buffer at
***************
*** 359,366 **** XLogReadBufferExtended(RelFileNode rnode, ForkNumber forknum,
  			log_invalid_page(rnode, forknum, blkno, true);
  			return InvalidBuffer;
  		}
- 	}
  
  	return buffer;
  }
  
--- 338,364 ----
  			log_invalid_page(rnode, forknum, blkno, true);
  			return InvalidBuffer;
  		}
  
+ 	} else {
+ 
+ 		/* If page doesn't exist extend the file */
+ 		while (blkno >= smgrnblocks(smgr, forknum)) 
+ 		{
+ 			/* we do this in recovery only - no rel-extension lock needed */
+ 			Assert(InRecovery);
+ 			buffer = ReadBufferWithoutRelcache(rnode, forknum,
+ 											   P_NEW, mode, NULL);
+ 			/* Take care not to extend the relation past where it's needed */
+ 			if (BufferGetBlockNumber(buffer) == blkno) 
+ 				return buffer;
+ 			ReleaseBuffer(buffer);
+ 		}
+ 
+ 		/* page now exists in file */
+ 		buffer = ReadBufferWithoutRelcache(rnode, forknum, blkno,
+ 										   mode, NULL);
+ 	}
+ 	
  	return buffer;
  }