This fixes the code like this:

	bh = sb_find_get_block (sb, tmp + j);
	if ((bh && DATA_BUFFER_USED(bh)) || tmp != fs32_to_cpu(sb, *p)) {
		retry = 1;
		brelse (bh);
		goto next1;
	}
	bforget (bh);

sb_find_get_block() ordinarily returns a buffer_head with b_count>=2, and
this code assume that in case if "b_count>1" buffer is used, so this caused
infinite loop.

(akpm: that is-the-buffer-busy code is incomprehensible.  Good riddance.  Use
of block_truncate_page() seems sane).
Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>