Re: [PATCH v3] fs: Replace user_access_{begin/end} by scoped user access

[Christophe Leroy (CS GROUP)]

Le 18/03/2026 à 16:53, Linus Torvalds a écrit :
> On Wed, 18 Mar 2026 at 08:49, Linus Torvalds
> <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> >      #define dirent_size(dirent, len) offsetof(typeof(dirent), d_name[len])
>
> That 'typeof(dirent)' needs to be 'typeof(*(dirent))' to be convenient.
>
> It was correct in the patch I attached, but I'll just point it out anyway.
>
> And we actually have a helper macro for that: struct_offset(). Which
> wasn't what I used in that attached patch, but *should* have been.
>
> IOW, the macro should look something like
>
>      #define dirent_size(dirent, len) struct_offset(dirent, d_name[len])

Sending v5 (series of 2) with your suggested patch as patch 1.

Following feedback from David which I tend to agree with, I left it as 
you did initialy.

struct_offset() has only one caller and I don't feel it has much added 
value compared to offsetof(typeof(),) pattern which is more explicit and 
already used 144 times in the kernel:

$ git grep "offsetof(typeof(" | wc -l
144

Christophe