On 2025/3/10 17:54, Gao Xiang wrote:
Hi folks,
The current 32-bit block addressing limits EROFS to a 16TiB maximum
volume size with 4KiB blocks. However, several new use cases now
require larger capacity support:
- Massive datasets for model training to boost random sampling
performance for each epoch;
- Object storage clients using EROFS direct passthrough.
This extends core on-disk structures to support 48-bit block addressing,
such as inodes, device slots, and inode chunks.
In addition, it introduces an mtime field to 32-byte compact inodes for
basic timestamp support, as well as expands the superblock root NID to
an 8-byte rootnid_8b for out-of-place update incremental builds.
In order to support larger images beyond 32-bit block addressing and
efficient indexing of large compression units for compressed data, and
to better support popular compression algorithms (mainly Zstd) that
still lack native fixed-sized output compression support, introduce
byte-oriented encoded extents, so that these compressors are allowed
to retain their current methods.
Therefore, it speeds up Zstd image building a lot by using:
Processor: Intel(R) Xeon(R) Platinum 8163 CPU @ 2.50GHz * 96
Dataset: enwik9
Build time Size Type Command Line
3m52.339s 266653696 FO -C524288 -zzstd,22
3m48.549s 266174464 FO -E48bit -C524288 -zzstd,22
0m12.821s 272134144 FI -E48bit -C1048576 --max-extent-bytes=1048576 -zzstd,22
It has been stress-tested on my local setup for a while without any
strange happens.
Cool, good work! For this serial,
Acked-by: Chao Yu <chao@xxxxxxxxxx>
Hoping to grab continuous free slots to check the details, then we can
change it to rvb status before merge window. :)