[PATCH 0/2] xfs: handle inode extent count mismatch

[Dave Chinner <david@fromorbit.com>]

Hi folks,

Wen Xu provided an image that caused a crash allocating an extent.
The AGFL was corrupt, as was the inode data fork extent count. The
combination of the two corruptions could lead to a delalloc extent
being allocated on write, and then when allocation fails because the
AGFL was corrupt, it would try to punch out the delalloc extent
which would then try to convert the format of the extent list in the
inode data fork without a transaction. This would crash.

The following two patches address this - the first makes
xfs_bunmapi() return EFSCORRUPTED if it tries to change the inode
fork format without a transaction context and avoids the crash. THe
second makes the inode verifier detect this specific inode fork
corruption and prevents any attempt to access it with EFSCORRUPTED.

Comments?

Cheers,

Dave.