Re: [PATCH v2] erofs: use dedicated meta inodes for file-backed mounts

[Gao Xiang]

Hi Christoph,

On Tue, Aug 18, 2026 at 10:55:47PM -0700, Christoph Hellwig wrote:
> On Tue, Aug 11, 2026 at 05:07:17PM +0800, Gao Xiang wrote:
> > access on file-backed mounts (although I still don't think it is
> > necessary due to the EROFS immutable model). As the result, metadata
> > cache won't use the page cache of backing inodes anymore.
> > 
> > The "managed cache" was originally used to cache physical compressed
> > data according to the current cache strategy and I/O patterns; since
> > file-backed mounts also need to access physical data for metadata
> > access, it's natural to reuse the managed cache for this too, providing
> > a unique inode for all physical data access.
> 
> This look sane.  Any reason to not use the meta inode unconditionally
> to simplify the code?

I guess you meant avoid using bd_inode page cache?

I'm not sure if it simplifies a lot, also like fadvise(WILLNEED) to blkdev
can perform to bd_inode too so I think it can still have some benefits.

I think bd_inode page cache can be used for filesystems so maybe leave it
as-is for now, or maybe a follow-up work if it's really needed.

Thanks,
Gao Xiang

> 
>