gfs2: don't use buffer_heads in gfs2_allocate_page_backing

}

/**

 * gfs2_allocate_page_backing - Use bmap to allocate blocks

 * gfs2_allocate_page_backing - Allocate blocks for a write fault

 * @page: The (locked) page to allocate backing for

 *

 * We try to allocate all the blocks required for the page in

 * one go. This might fail for various reasons, so we keep

 * trying until all the blocks to back this page are allocated.

 * If some of the blocks are already allocated, thats ok too.

 * We try to allocate all the blocks required for the page in one go.  This

 * might fail for various reasons, so we keep trying until all the blocks to

 * back this page are allocated.  If some of the blocks are already allocated,

 * that is ok too.

 */

static int gfs2_allocate_page_backing(struct page *page)

{

	struct inode *inode = page->mapping->host;

	struct buffer_head bh;

	unsigned long size = PAGE_SIZE;

	u64 lblock = page->index << (PAGE_SHIFT - inode->i_blkbits);

	u64 pos = page_offset(page);

	u64 size = PAGE_SIZE;

	do {

		bh.b_state = 0;

		bh.b_size = size;

		gfs2_block_map(inode, lblock, &bh, 1);

		if (!buffer_mapped(&bh))

		struct iomap iomap = { };

		if (gfs2_iomap_get_alloc(page->mapping->host, pos, 1, &iomap))

			return -EIO;

		size -= bh.b_size;

		lblock += (bh.b_size >> inode->i_blkbits);

		iomap.length = min(iomap.length, size);

		size -= iomap.length;

		pos += iomap.length;

	} while (size > 0);

	return 0;

}