[PATCH 0/2] maple_tree: Fix mas_prev() state regression.

[Liam R. Howlett]

Pedro Falcato contacted me on IRC with an mprotect regression which was
bisected back to the iterator changes for maple tree.  Root cause
analysis showed the mas_prev() running off the end of the VMA space
(previous from 0) followed by mas_find(), would skip the first value.

This patch set introduces maple state underflow/overflow so the sequence
of calls on the maple state will return what the user expects.

Liam R. Howlett (2):
  maple_tree: Add mas_active() to detect in-tree walks
  maple_tree: Add MAS_UNDERFLOW and MAS_OVERFLOW states

 include/linux/maple_tree.h |  11 ++
 lib/maple_tree.c           | 221 +++++++++++++++++++++++++++----------
 lib/test_maple_tree.c      |  87 ++++++++++++---
 3 files changed, 246 insertions(+), 73 deletions(-)

-- 
2.39.2