Re: [PATCH v2] fuse: keep inode->i_blkbits constant

[Joanne Koong <joannelkoong@gmail.com>]

On Tue, Aug 12, 2025 at 1:27 AM Miklos Szeredi <miklos@szeredi.hu> wrote:
>
> On Thu, 7 Aug 2025 at 19:51, Joanne Koong <joannelkoong@gmail.com> wrote:
> >
> > With fuse now using iomap for writeback handling, inode blkbits changes
> > are problematic because iomap relies on inode->i_blkbits for its
> > internal bitmap logic. Currently we change inode->i_blkbits in fuse to
> > match the attr->blksize value passed in by the server.
> >
> > This commit keeps inode->i_blkbits constant in fuse. Any attr->blksize
> > values passed in by the server will not update inode->i_blkbits. The
> > client-side behavior for stat is unaffected, stat will still reflect the
> > blocksize passed in by the server.
>
> Not quite.  You also need to save ilog2(attr->blksize) in
> fi->orig_i_blkbits and restore it after calling generic_fillattr() in
> fuse_update_get_attr() just like it's done for i_mode and i_ino.
>

Oh I see, thanks. I'll resubmit this. And will do the same logic for
the fuseblk i_blkbits patch I submitted yesterday.

Thanks,
Joanne

> Thanks,
> Miklos