udf: convert to new aops

Convert udf to new aops.  Also seem to have fixed pagecache corruption in
udf_adinicb_commit_write -- page was marked uptodate when it is not.  Also,
fixed the silly setup where prepare_write was doing a kmap to be used in
commit_write: just do kmap_atomic in write_end.  Use libfs helpers to make
this easier.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: <bfennema@falcon.csc.calpoly.edu>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 1652b2c..6ff8151 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -133,10 +133,13 @@
 	return block_read_full_page(page, udf_get_block);
 }
 
-static int udf_prepare_write(struct file *file, struct page *page,
-			     unsigned from, unsigned to)
+static int udf_write_begin(struct file *file, struct address_space *mapping,
+			loff_t pos, unsigned len, unsigned flags,
+			struct page **pagep, void **fsdata)
 {
-	return block_prepare_write(page, from, to, udf_get_block);
+	*pagep = NULL;
+	return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+				udf_get_block);
 }
 
 static sector_t udf_bmap(struct address_space *mapping, sector_t block)
@@ -148,8 +151,8 @@
 	.readpage	= udf_readpage,
 	.writepage	= udf_writepage,
 	.sync_page	= block_sync_page,
-	.prepare_write	= udf_prepare_write,
-	.commit_write	= generic_commit_write,
+	.write_begin		= udf_write_begin,
+	.write_end		= generic_write_end,
 	.bmap		= udf_bmap,
 };