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Date: Sun, 4 Dec 2016 21:49:36 +0900
From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Minchan Kim <minchan@kernel.org>,
        Steven Allen <steven@stebalien.com>,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [PATCH] zram: restrict add/remove attributes to root only
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On (12/04/16 12:28), Greg KH wrote:
> > [..]
> > 
> > > Why can't a normal user read the attribute?  Does a read actually modify
> > > something?
> > 
> > yes, it does.
> 
> Oh that's totally and completely broken then.
> 
> Reading from a sysfs file should NEVER cause side affects to the system.
> Please fix up this api.

we have a mechanism for such API changes -- there is a bunch of deprecated
sysfs attrs that we will remove in 4.11; so I'll mark hot_add/hot_remove
as deprecated and switch to char device (as you suggested). thanks.

	-ss