[PATCH 0/4] rework bitmap_parselist

From: Yuri Norov
Date: Sun Dec 23 2018 - 04:46:09 EST


bitmap_parselist evolved from a pretty simple idea for long and now lacks
for refactoring. It is not structured, has nested loops and a set of
opaque-named variables. All this leads to extremely hard understanding
of the code. Once during the optimization of it I missed a scenario which
leads to kernel hangup. Tetsuo Handa spotted this and found it simpler to
rewrite the code instead fixing it. (Though, that attempt had some flaws.)
https://lkml.org/lkml/2018/4/1/93

Things are more complicated than they may be because bitmap_parselist()
is part of user interface, and its behavior should not change.

In this patchset __bitmap_parselist() is split to a set of smaller
functions doing only one thing.

Yury Norov (4):
bitmap_parselist: don't calculate length of the input string
bitmap_parselist: move part of logic to helpers
bitmap_parselist: rework input string parser
test_bitmap: add testcases for bitmap_parselist

lib/bitmap.c | 294 ++++++++++++++++++++++++++++++----------------
lib/test_bitmap.c | 18 ++-
2 files changed, 208 insertions(+), 104 deletions(-)

--
2.17.1