[v4,0/4] xfs: fix stale disk exposure after crash

Message

Darrick J. Wong May 23, 2020, 4:49 p.m. UTC

Hi all,

This set of 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 fixes a minor
error encountered during writeback; and the third patch fixes
speculative preallocation to work when the EOF block could be unwritten.

v3 puts the extent tree walk into the dynamic prealloc sizing function.
v4 fixes a bug with walking the extent map backwards.

If you're going to start using this mess, you probably ought to just
pull from my git trees, which are linked below.

This is an extraordinary way to destroy everything.  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
---
 fs/xfs/libxfs/xfs_bmap.c |   29 +++++++-----
 fs/xfs/xfs_iomap.c       |  107 +++++++++++++++++++++++-----------------------
 2 files changed, 71 insertions(+), 65 deletions(-)