Hi all, These two patches try to shrink the window during which a crash during writeback can expose stale disk contents. The first patch causes delalloc reservations to be converted to unwritten extents for any writeback that's going on within EOF. The second patch selectively relaxes the unwritten writeout requirement when the entire file is being flushed (ala fsync) and ensures that writeback of a range after the ondisk EOF is expanded downwards to the old EOF to ensure that increasing a file's size doesn't leave us vulnerable to exposure of stale disk contents from a previous speculative allocation. This solves the regressions in generic/536 and generic/042. If you're going to start using this mess, you probably ought to just pull from my git trees, which are linked below. This has been lightly tested with fstests. Enjoy! Comments and questions are, as always, welcome. --D kernel git tree: https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=stale-exposure xfsprogs git tree: https://git.kernel.org/cgit/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=stale-exposure
