[Devel] [PATCH rh7] fs/cleancache: fix data invalidation in the cleancache during direct_io

[Alexey Kuznetsov]

Hello!

Good job!

Before submitting this to mainstream look
at truncate_inode_pages.

It has condition:

if (mapping->nrpages == 0 && mapping->nrexceptional == 0)
                return;

I have no idea what are those exceptions are, but it definitely
looks illegal to check only for nrpages in invalidate_inode_pages2_range,
it clears exceptional entries as well.

Also I see no point in invalidation of cleancache on entry
to these routines. It is waste of time, cleancache will be
repopulated by invalidation (which it stupid, of course).
It is enough to do this once at exit.