Re: [PATCH 0/5] erofs: basic sub-page compressed data support

[Yue Hu]

On Wed,  6 Dec 2023 17:10:52 +0800
Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx> wrote:

> Hi folks,
> 
> Recently, there are two new cases so that we need to add a preliminary
> sub-page block support for compressed files;
> 
>  - As Android folks requested, Android ecosystem itself is now switching
>    to 16k page size for their arm64 devices.  They needs an option of
>    4k-block image compatibility on their new 16k devices;
> 
>  - Some arm64 cloud servers use 64k page size for their optimized
>    workloads, but 4k-block EROFS container images need to be parsed too.
> 
> So this patchset mainly addresses the requirements above with a very
> very simple approach as a start: just allocate short-lived temporary
> buffers all the time to keep compressed data if sub-page blocks are
> identified.  In other words, no inplace/cache decompression for
> the preliminary support.
> 
> This patchset survives EROFS stress test on my own testfarms.
> 
> Thanks,
> Gao Xiang
> 
> Gao Xiang (5):
>   erofs: support I/O submission for sub-page compressed blocks
>   erofs: record `pclustersize` in bytes instead of pages
>   erofs: fix up compacted indexes for block size < 4096
>   erofs: refine z_erofs_transform_plain() for sub-page block support
>   erofs: enable sub-page compressed block support
> 
>  fs/erofs/decompressor.c |  81 +++++++++------
>  fs/erofs/inode.c        |   6 +-
>  fs/erofs/zdata.c        | 224 ++++++++++++++++++----------------------
>  fs/erofs/zmap.c         |  32 +++---
>  4 files changed, 169 insertions(+), 174 deletions(-)
> 

Reviewed-by: Yue Hu <huyue2@xxxxxxxxxxx>