On Thu, Apr 05, 2018 at 06:37:24PM +0530, Chandan Rajendra wrote: > Sorry, I wasn't clear enough with my explaination. I actually meant to say > that not all blocks mapped by a page might be dirty and hence only a subset > of the dirty blocks might need to be written to the disk. But we only track dirtiness on a per-page level. That's all the page cache gives us. Remember, the function name is ext4_bio_write_page() or {btrfs,xfs,ext4}_writepage() --- we will always be writing a full page at a time. - Ted