On Sun, Nov 23, 2008 at 01:14:52PM +0100, Francis Moreau wrote: > Hello, > > Thanks for your answer. > > Andreas Dilger <adilger@xxxxxxx> writes: > > > There may be multiple buffers on a single page, and in some cases > > one buffer on a page can be uptodate while another buffer on the > > same page is not. > > Can this really happen ? Yes. > Are there any cases where a page can be partially uptodate ? Consider a filesystem with 1k blocks and a system with a page size of 4k. You have a buffer_head for each of the four blocks that are being kept in the page, and you want to track their dirty state independently. For file data, no this doesn't happen. But for metadata, it happens quite easily. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
