Re: [PATCH] erofs: fix file-backed mounts over FUSE

From: Gao Xiang
Date: Thu Nov 14 2024 - 01:39:10 EST




On 2024/11/14 14:34, Al Viro wrote:
On Thu, Nov 14, 2024 at 02:23:27PM +0800, Gao Xiang wrote:

3) AFAICS, (buf->kmap_type == EROFS_KMAP) == (buf->base != NULL). What's
the point of having that as a separate field?

Once buf->kmap_type has EROFS_KMAP and EROFS_KMAP_ATOMIC, but it
seems that it can be cleaned up now.

I will clean up later but it's a seperate story.


4) Why bother with union? Just have buf->file serve as your buf->use_fp
and be done with that...

I'd like to leave `struct erofs_buf` as small as possible since
it's on stack.

enum + bool eats at least as much as a pointer, and if it's on stack...
an extra word is really noise - it's not as if you had a plenty of
those in the current call chain at any given point.

Yeah, enum can be avoided now, I will clean up this enum
as a seperate effort.

Thanks,
Gao Xiang