Huawei Adding New LZ4 Inplace Decompression To EROFS File-System

Huawei's EROFS Linux read-only file-system continues to be improved upon and with the upcoming Linux 5.3 kernel cycle will see yet more improvements.

EROFS has already supported native file-system compression for help conserving space with this read-only file-system Huawei has been working on for use particularly by mobile devices but other use-cases as well. Queued up into staging-next ahead of the Linux 5.3 merge window is a new decompression framework.

This new EROFS support allows for LZ4 decompression to happen in-place so that data decompression can be done without any memory copies. This, of course, is helping out performance. Gao Xiang of Huawei commented on one of the patches, "On kirin980 platform, sequential read is slightly improved to 778MiB/s after the new decompression backend is used."

Already as a follow-up patch to the new framework, EROFS is switching to use this code while dropping their older decompression code.

This support comes following upstream LZ4 seeing in-place decompression functionality via Facebook developers.