Re: [PATCH] [Request for inclusion] Filesystem in Userspace

Greg KH
2004-11-17T18:17:53Z

On Wed, Nov 17, 2004 at 06:56:13PM +0100, Miklos Szeredi wrote:
>
> > /sys/fs used to exist for for some. Moreover, /sys/fs/foofs/ was added
> > automagically when foofs file system type was registered. But it was
> > ultimately removed, because nobody took the time to fix all races
> > between accessing /sys/fs/foofs/gadget and
> > umount/filesystem-module-unloading.
>
> I don't see why this would be any harder for filesystem code than for
> other types of drivers. Maybe someone can enlighten me.

Think about putting the /sys/sysfs entry into the tree before sysfs has
been fully initialized :)

There are other fun races that Al Viro pointed out dealing with
superblock lifetimes from what I remember.

> Anyway, I can try to clean it up: remove all the racy bits and keep
> what I need (which is mainly just the /sys/fs directory). Where can I
> find the most recent version of this?

Look through the 2.5 kernel series, it was in there for a while.

But don't really worry about it, just create /sys/fs/ and use it to put
your own stuff in it if you want. Don't try to recreate the old, buggy
stuff :)

Good luck,

greg k-h