xfs: eagerly remove vmap mappings to avoid upsetting Xen

XFS leaves stray mappings around when it vmaps memory to make it
virtually contigious.  This upsets Xen if one of those pages is being
recycled into a pagetable, since it finds an extra writable mapping of
the page.

This patch solves the problem in a brute force way, by making XFS
always eagerly unmap its mappings.  David Chinner says this shouldn't
have any performance impact on filesystems with default block sizes;
it will only affect filesystems with large block sizes.

Signed-off-by: Jeremy Fitzhardinge <[email protected]>
Acked-by: David Chinner <[email protected]>
Cc: Nick Piggin <[email protected]>
Cc: XFS masters <[email protected]>
Cc: Stable kernel <[email protected]>
Cc: Morten =?utf-8?q?B=C3=B8geskov?= <[email protected]>
Cc: Mark Williamson <[email protected]>

0 files changed, 0 insertions, 0 deletions