Re: [PATCH 1/2] Use list.h instead of file_system_type next

From: Al Viro
Date: Sat May 04 2019 - 09:20:43 EST


On Sat, May 04, 2019 at 05:45:48AM -0400, Carmeli Tamir wrote:
> From: Tamir <carmeli.tamir@xxxxxxxxx>
>
> Changed file_system_type next field to list_head and refactored
> the code to use list.h functions.

... except that list_head is not a good match here. For one thing,
we never walk that thing backwards. For another, filesystem
can be used without ever going through register_filesystem(),
making your data structure quite a mess - e.g. use of list_empty()
(a perfectly normal list.h primitive) on it might oops on some
instances.

IOW, what you are making is not quite list_head and pretending it
to be list_head is asking for serious headache down the road.

Frankly, what's the point? Reusing an existing data type, to
avoid DIY is generally a good advice, but then you'd better
make sure that existing type *does* fit your needs and that
your creation is playing by that type's rules.

This patch does neither...

NAKed-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>