From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Minchan Kim <minchan@kernel.org>,
Jerome Marchand <jmarchan@redhat.com>,
Nitin Gupta <ngupta@vflare.org>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/8] introduce dynamic device creation/removal
Date: Mon, 2 Mar 2015 14:18:05 +0000 [thread overview]
Message-ID: <20150302141805.6e0ed07a@www.etchedpixels.co.uk> (raw)
In-Reply-To: <20150227145109.b5656bdf853c2d283bf9268e@linux-foundation.org>
> > This is a long term plan, of course, but I'd like to see sysfs functions go away
> > in a year or so. What do you think?
>
> hoo boy. Creating a /dev node and doing ioctls on it is really old
> school. So old school that I've forgotten why we don't do it any more.
>
> Hopefully Alan can recall the thinking?
Gee.. pass me the walking stick and the pipe !
The problem we used to have with it was re-use of /dev nodes and
permissions. For example if I create a ZRAM instance and then we crash
and my /dev is persistent then next boot I can potentially be opening
that left over node (or it may even be forgotten), which has old and
stale permissions on it.
With devtmpfs it's a bit easier and saner.
The old abuser of this was the old PCMCIA layer which has more exciting
versions of the problem as it used /tmp for some nodes.
Switching to sysfs probably fits better but the problem is the generic
one of revoking access rights to an object.
Alan
prev parent reply other threads:[~2015-03-02 14:18 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-26 14:10 Sergey Senozhatsky
2015-02-26 14:10 ` [PATCH 1/8] zram: cosmetic ZRAM_ATTR_RO code formatting tweak Sergey Senozhatsky
2015-02-26 14:10 ` [PATCH 2/8] zram: use idr instead of `zram_devices' array Sergey Senozhatsky
2015-02-26 14:10 ` [PATCH 3/8] zram: factor out device reset from reset_store() Sergey Senozhatsky
2015-02-26 14:10 ` [PATCH 4/8] zram: add dynamic device add/remove functionality Sergey Senozhatsky
2015-02-26 14:10 ` [PATCH 5/8] zram: return zram device_id value from zram_add() Sergey Senozhatsky
2015-02-26 14:10 ` [PATCH 6/8] zram: allow automatic new zram device_id assignment Sergey Senozhatsky
2015-02-26 14:10 ` [PATCH 7/8] zram: remove max_num_devices limitation Sergey Senozhatsky
2015-02-26 14:10 ` [PATCH 8/8] zram: report every added and removed device Sergey Senozhatsky
2015-02-27 22:51 ` [PATCH 0/8] introduce dynamic device creation/removal Andrew Morton
2015-02-28 1:33 ` Sergey Senozhatsky
2015-02-28 1:50 ` Sergey Senozhatsky
2015-02-28 3:34 ` Sergey Senozhatsky
2015-02-28 4:29 ` Andrew Morton
2015-03-02 14:18 ` Alan Cox [this message]
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