[PATCH 0/2] btrfs: Enhance btrfs handling compression and

[Qu Wenruo <wqu@suse.com>]

James Harvey reported one corruption where lzo compressed extent without
data csum is causing "decompress failed" kernel message, and then
serious random kernel memory corruption.

For the "decrompress failed" kernel message, it's indeed corrupted
compressed data.
However we can still harden btrfs lzo callers by do extra check on the
lzo compressed data before really decompress it.
It's done mostly based on the total length recorded in the first 4 bytes
of a compressed extent.

It should catch such corruption early.
However the random kernel memory corruption still can't be reproduced
even with the same binary dump.

On the other hand, even btrfs(5) only specifies that nodatacow or
nodatasum will disable compression, it should also work on the same
inode flags level.
For NODATACOW, it's working as epxected, but for NODATASUM alone, it's
not working properly, the 2nd patch will enhance such check so even for
NODATASUM inode, compressio will also be disabled.

Qu Wenruo (2):
  btrfs: inode: Don't compress if NODATASUM or NODATACOW set
  btrfs: lzo: Avoid decompressing obviously corrupted data

 fs/btrfs/compression.h | 1 +
 fs/btrfs/inode.c       | 8 ++++++++
 fs/btrfs/lzo.c         | 4 ++++
 3 files changed, 13 insertions(+)

-- 
2.17.0