fs: move code out of buffer.c

Move invalidate_bdev, block_sync_page into fs/block_dev.c.  Export
kill_bdev as well, so brd doesn't have to open code it.  Reduce
buffer_head.h requirement accordingly.

Removed a rather large comment from invalidate_bdev, as it looked a bit
obsolete to bother moving.  The small comment replacing it says enough.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 27 insertions, 3 deletions

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 7866cdd9fe70..69a5b6fbee2b 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -17,6 +17,7 @@
 #include <linux/module.h>
 #include <linux/blkpg.h>
 #include <linux/buffer_head.h>
+#include <linux/swap.h>
 #include <linux/pagevec.h>
 #include <linux/writeback.h>
 #include <linux/mpage.h>
@@ -25,6 +26,7 @@
 #include <linux/namei.h>
 #include <linux/log2.h>
 #include <linux/kmemleak.h>
+#include <linux/cleancache.h>
 #include <asm/uaccess.h>
 #include "internal.h"
 
@@ -82,13 +84,35 @@ static sector_t max_block(struct block_device *bdev)
 }
 
 /* Kill _all_ buffers and pagecache , dirty or not.. */
-static void kill_bdev(struct block_device *bdev)
+void kill_bdev(struct block_device *bdev)
 {
-        if (bdev->bd_inode->i_mapping->nrpages == 0)
+        struct address_space *mapping = bdev->bd_inode->i_mapping;
+
+        if (mapping->nrpages == 0)
                 return;
+
         invalidate_bh_lrus();
-        truncate_inode_pages(bdev->bd_inode->i_mapping, 0);
+        truncate_inode_pages(mapping, 0);
 }       
+EXPORT_SYMBOL(kill_bdev);
+
+/* Invalidate clean unused buffers and pagecache. */
+void invalidate_bdev(struct block_device *bdev)
+{
+        struct address_space *mapping = bdev->bd_inode->i_mapping;
+
+        if (mapping->nrpages == 0)
+                return;
+
+        invalidate_bh_lrus();
+        lru_add_drain_all();    /* make sure all lru add caches are flushed */
+        invalidate_mapping_pages(mapping, 0, -1);
+        /* 99% of the time, we don't need to flush the cleancache on the bdev.
+         * But, for the strange corners, lets be cautious
+         */
+        cleancache_flush_inode(mapping);
+}
+EXPORT_SYMBOL(invalidate_bdev);
 
 int set_blocksize(struct block_device *bdev, int size)
 {