Hello everyone, Here's a respin of the O_DIRECT locking changes. There are some minor updates, mostly cleanups based on suggestions from Zach Brown and Dave Chinner. Linus found a deadlock between the placeholders and the page fault handler when userland uses an mmap of the file as the O_DIRECT buffer. I'm getting around that by capping placeholder extents at DIO_PAGES (64) intervals when the file has mappings. This matches the interval used by get_user_pages and makes sure get_user_pages has been called on a given range in the address space before placeholders are added. I also hit a stale data exposure when get_block returns data past the end of the placeholder extent. A concurrent readpage could come in and find metadata before the data had gotten to disk. The fix is to only ask get_block for data up to the end of the placeholder. Generally, this isn't a problem because the common case is for a single placeholder to cover the entire DIO. So the suboptimal allocation result wouldn't happen very often. -chris - 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
