[PATCH v3 0/2] ext4: add hash Kunit tests and optimize str2hashbuf

From: Guan-Chun Wu

Date: Mon Apr 13 2026 - 02:52:13 EST


This series adds Kunit tests for fs/ext4/hash.c and refactors
the str2hashbuf_{signed,unsigned}() helpers.

Patch 1 adds test coverage for ext4fs_dirhash(), including the main
hash variants and relevant edge cases.

Patch 2 simplifies the str2hashbuf helper implementation by processing
input in 4-byte chunks and removing function-pointer dispatch. This also
reduces overhead and shows roughly 2x improvement on longer inputs in
local testing.

Thanks,
Guan-Chun Wu

Link: https://lore.kernel.org/lkml/20251122043929.1908643-1-409411716@xxxxxxxxxxxxxx/

---

v2 -> v3 :

- Added Kunit tests for fs/ext4/hash.c.

---

Guan-Chun Wu (2):
ext4: add Kunit coverage for directory hash computation
ext4: improve str2hashbuf by processing 4-byte chunks and removing
function pointers

fs/ext4/Makefile | 2 +-
fs/ext4/hash-test.c | 546 ++++++++++++++++++++++++++++++++++++++++++++
fs/ext4/hash.c | 64 ++++--
3 files changed, 589 insertions(+), 23 deletions(-)
create mode 100644 fs/ext4/hash-test.c

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2.34.1