mm: move PageDoubleMap bit

Patch series "Fix PageDoubleMap".

This is a purely theoretical problem for now as none of the filesystems
which use PG_private_2 (ie PG_fscache) are being converted at this time,
but it's confusing to leave it like this.

This patch (of 2):

PG_private_2 is defined as being PF_ANY (applicable to tail pages as well
as regular & head pages).  That means that the first tail page of a
double-map page will appear to have Private2 set.  Use the Workingset bit
instead which is defined as PF_HEAD so any attempt to access the
Workingset bit on a tail page will redirect to the head page's Workingset
bit.

Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Zi Yan <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions