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, 3 insertions, 0 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index cec429d76ab0..e853ba5eddd4 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2092,6 +2092,7 @@ extern void bd_forget(struct inode *inode);
 extern void bdput(struct block_device *);
 extern void invalidate_bdev(struct block_device *);
 extern int sync_blockdev(struct block_device *bdev);
+extern void kill_bdev(struct block_device *);
 extern struct super_block *freeze_bdev(struct block_device *);
 extern void emergency_thaw_all(void);
 extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
@@ -2099,6 +2100,7 @@ extern int fsync_bdev(struct block_device *);
 #else
 static inline void bd_forget(struct inode *inode) {}
 static inline int sync_blockdev(struct block_device *bdev) { return 0; }
+static inline void kill_bdev(struct block_device *bdev) {}
 static inline void invalidate_bdev(struct block_device *bdev) {}
 
 static inline struct super_block *freeze_bdev(struct block_device *sb)
@@ -2415,6 +2417,7 @@ extern ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
                                 unsigned long nr_segs, loff_t pos);
 extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
                         int datasync);
+extern void block_sync_page(struct page *page);
 
 /* fs/splice.c */
 extern ssize_t generic_file_splice_read(struct file *, loff_t *,