2011/05/24 17:57, Lukas Czerner wrote:
Hi Kazuya, I am really sorry for late answer. I think you're partly right. my solution is not good, but I still think that your is not good as well. I need to look at this again and more closely, sorry. What do you think about this: ext4_ext_next_allocated_block() should return next allocated block, however instead it in some cases returns EXT_MAX_BLOCK, which points at the last logical block in a file, which however in some cases might be equal to the last not allocated block, not first allocated block in subsequent extent. And boom, we have (next == lblock).
I think so, too.
So if we want to really return next allocated block (or more specifically, next block which we can not allocate), we should in those cases return EXT_MAX_BLOCK+1. And we should do this in ext4_ext_put_gap_in_cache() as well when there is no extent yet. Also note that as I said EXT_MAX_BLOCK means maximum logical block, however we use it as lenght in ext4_ext_put_gap_in_cache() which does not sound right either. It seems all a little bit messy :-/. I need to look at it and try it to see if it would work, but I think it does make sense. What do you think?
AFAIK, it's the best way to fix this problem. But I have no idea that doesn't increase the size of struct ext4_ext_cache. I'm looking forward to seeing the patch. Regards, Kazuya Mio -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
