The xattr bloom filter feature is used to boost the negative xattr lookup. Refer to the kernel patches [1] for more details.
[1] https://lore.kernel.org/all/[email protected]/ Jingbo Xu (3): erofs-utils: add xxh32 library erofs-utils: update on-disk format for xattr bloom filter erofs-utils: mkfs: enable xattr bloom filter include/erofs/config.h | 1 + include/erofs/internal.h | 1 + include/erofs/xxhash.h | 35 +++++++++++++++++ include/erofs_fs.h | 10 ++++- lib/Makefile.am | 3 +- lib/xattr.c | 62 +++++++++++++++++++++++++++-- lib/xxhash.c | 85 ++++++++++++++++++++++++++++++++++++++++ mkfs/main.c | 6 +++ 8 files changed, 198 insertions(+), 5 deletions(-) create mode 100644 include/erofs/xxhash.h create mode 100644 lib/xxhash.c -- 2.19.1.6.gb485710b
