clean up write_begin usage for directories in pagecache

For filesystem that implement directories in pagecache we call
block_write_begin with an already allocated page for this code, while the
normal regular file write path uses the default block_write_begin behaviour.

Get rid of the __foofs_write_begin helper and opencode the normal write_begin
call in foofs_write_begin, while adding a new foofs_prepare_chunk helper for
the directory code.  The added benefit is that foofs_prepare_chunk has
a much saner calling convention.

Note that the interruptible flag passed into block_write_begin is always
ignored if we already pass in a page (see next patch for details), and
we never were doing truncations of exessive blocks for this case either so we
can switch directly to block_write_begin_newtrunc.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 9 deletions

diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 348805c..2f4dfbc 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -765,14 +765,6 @@ ext2_readpages(struct file *file, struct address_space *mapping,
 	return mpage_readpages(mapping, pages, nr_pages, ext2_get_block);
 }
 
-int __ext2_write_begin(struct file *file, struct address_space *mapping,
-		loff_t pos, unsigned len, unsigned flags,
-		struct page **pagep, void **fsdata)
-{
-	return block_write_begin_newtrunc(file, mapping, pos, len, flags,
-					pagep, fsdata, ext2_get_block);
-}
-
 static int
 ext2_write_begin(struct file *file, struct address_space *mapping,
 		loff_t pos, unsigned len, unsigned flags,
@@ -781,7 +773,8 @@ ext2_write_begin(struct file *file, struct address_space *mapping,
 	int ret;
 
 	*pagep = NULL;
-	ret = __ext2_write_begin(file, mapping, pos, len, flags, pagep, fsdata);
+	ret = block_write_begin_newtrunc(file, mapping, pos, len, flags,
+					 pagep, fsdata, ext2_get_block);
 	if (ret < 0)
 		ext2_write_failed(mapping, pos + len);
 	return ret;