From: Tejun Heo <tj@kernel.org>
To: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org, NeilBrown <neilb@suse.de>,
stable@vger.kernel.org
Subject: Re: [PATCH] sysfs: correctly handle read offset on PREALLOC attrs
Date: Thu, 23 Jun 2016 17:18:45 -0400 [thread overview]
Message-ID: <20160623211845.GL3262@mtj.duckdns.org> (raw)
In-Reply-To: <146662093622.3726.10220135910756738018.stgit@buzz>
On Wed, Jun 22, 2016 at 09:42:16PM +0300, Konstantin Khlebnikov wrote:
> Attributes declared with __ATTR_PREALLOC use sysfs_kf_read() which returns
> zero bytes for non-zero offset. This breaks script checkarray in mdadm tool
> in debian where /bin/sh is 'dash' because its builtin 'read' reads only one
> byte at a time. Script gets 'i' instead of 'idle' when reads current action
> from /sys/block/$dev/md/sync_action and as a result does nothing.
>
> This patch adds trivial implementation of partial read: generate whole
> string and move required part into buffer head.
>
> Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
> Fixes: 4ef67a8c95f3 ("sysfs/kernfs: make read requests on pre-alloc files use the buffer.")
> Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=787950
> Cc: Stable <stable@vger.kernel.org> # v3.19+
Acked-by: Tejun Heo <tj@kernel.org>
Thanks.
--
tejun
next prev parent reply other threads:[~2016-06-23 21:18 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-22 18:42 [PATCH] sysfs: correctly handle read offset on PREALLOC attrs Konstantin Khlebnikov
2016-06-23 21:18 ` Tejun Heo [this message]
2016-09-05 13:25 ` Konstantin Khlebnikov
2016-09-05 13:46 ` Greg Kroah-Hartman
2016-09-05 14:02 ` Konstantin Khlebnikov
2016-09-05 14:15 ` Greg Kroah-Hartman
2016-09-05 14:13 ` Greg Kroah-Hartman
2016-09-05 14:17 ` Konstantin Khlebnikov
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