maple_tree: introduce mas_wr_store_type()

Introduce mas_wr_store_type() which will set the correct store type based
on a walk of the tree.  In mas_wr_node_store() the <= min_slots condition
is changed to < as if new_end is = to mt_min_slots then there is not
enough room.

mas_prealloc_calc() is also introduced to abstract the calculation used to
determine the number of nodes needed for a store operation.

In this change a call to mas_reset() is removed in the error case of
mas_prealloc().  This is only needed in the MA_STATE_REBALANCE case of
mas_destroy().  We can move the call to mas_reset() directly to
mas_destroy().

Also, add a test case to validate the order that we check the store type
in is correct.  This test models a vma expanding and then shrinking which
is part of the boot process.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sidhartha Kumar <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions