mm: only include blk_types in swap.h if CONFIG_SWAP is enabled

It's only needed for the CONFIG_SWAP-only use of bio_end_io_t.

Because CONFIG_SWAP implies CONFIG_BLOCK this will allow to drop some
ifdefs in blk_types.h.

Instead we'll need to add a few explicit includes that were implicit
before, though.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/staging/lustre/include/linux/lnet/types.h

@@ -34,6 +34,7 @@
 #define __LNET_TYPES_H__
 
 #include <linux/types.h>
+#include <linux/bvec.h>
 
 /** \addtogroup lnet
  * @{

drivers/staging/lustre/lustre/llite/rw.c

@@ -47,6 +47,7 @@
 #include <linux/pagemap.h>
 /* current_is_kswapd() */
 #include <linux/swap.h>
+#include <linux/bvec.h>
 
 #define DEBUG_SUBSYSTEM S_LLITE
 

fs/ntfs/aops.c

@@ -29,6 +29,7 @@
 #include <linux/buffer_head.h>
 #include <linux/writeback.h>
 #include <linux/bit_spinlock.h>
+#include <linux/bio.h>
 
 #include "aops.h"
 #include "attrib.h"

fs/ntfs/mft.c

@@ -23,6 +23,7 @@
 #include <linux/buffer_head.h>
 #include <linux/slab.h>
 #include <linux/swap.h>
+#include <linux/bio.h>
 
 #include "attrib.h"
 #include "aops.h"

fs/reiserfs/inode.c

@@ -19,6 +19,7 @@
 #include <linux/quotaops.h>
 #include <linux/swap.h>
 #include <linux/uio.h>
+#include <linux/bio.h>
 
 int reiserfs_commit_write(struct file *f, struct page *page,
 			  unsigned from, unsigned to);

fs/splice.c

@@ -17,6 +17,7 @@
  * Copyright (C) 2006 Ingo Molnar <mingo@elte.hu>
  *
  */
+#include <linux/bvec.h>
 #include <linux/fs.h>
 #include <linux/file.h>
 #include <linux/pagemap.h>

include/linux/swap.h

@@ -11,7 +11,6 @@
 #include <linux/fs.h>
 #include <linux/atomic.h>
 #include <linux/page-flags.h>
-#include <linux/blk_types.h>
 #include <asm/page.h>
 
 struct notifier_block;
@@ -352,6 +351,9 @@ extern int kswapd_run(int nid);
 extern void kswapd_stop(int nid);
 
 #ifdef CONFIG_SWAP
+
+#include <linux/blk_types.h> /* for bio_end_io_t */
+
 /* linux/mm/page_io.c */
 extern int swap_readpage(struct page *);
 extern int swap_writepage(struct page *page, struct writeback_control *wbc);