From: Jens Axboe <axboe@kernel.dk>
To: Damien Le Moal <damien.lemoal@wdc.com>, linux-block@vger.kernel.org
Cc: Matias Bjorling <matias.bjorling@wdc.com>
Subject: Re: [PATCH v3] nullb: Prevent use of legacy request queue mode
Date: Mon, 11 Feb 2019 19:55:27 -0700 [thread overview]
Message-ID: <a27e13e6-93a3-e7f7-cc67-a7169c8a44ad@kernel.dk> (raw)
In-Reply-To: <20190211234716.18816-1-damien.lemoal@wdc.com>
On 2/11/19 4:47 PM, Damien Le Moal wrote:
> When null_blk queue mode is specified together with modprobe/insmod, a
> check to prevent setting the nullb device queue mode to 1 (NULL_Q_RQ) is
> done. However, the same check is not performed when setting up a nullb
> device through configfs, resulting in a oops (NULL pointer dereference
> for the device request queue).
>
> Fix this problem by checking for an invalid queue mode value in
> null_validate_conf(), propagating -EINVAL to null_add_dev() if the queue
> mode is NULL_Q_RQ. While at it, also fix the propagation to user space
> of null_add_dev() return value when a nullb device is created through
> the power attribute of configfs.
>
> Finally, remove the "1=rq" value from the list of possible values of
> the queue_mode module argument to make it clear that this is no longer
> a valid setting.
I actually left that in there on purpose, to avoid breaking test
scripts. It's not the perfect solution, but I viewed it as the
lesser of two evils. Maybe we're fine now, I think blktests has
been fixed a while back?
--
Jens Axboe
next prev parent reply other threads:[~2019-02-12 2:55 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-11 23:47 [PATCH v3] nullb: Prevent use of legacy request queue mode Damien Le Moal
2019-02-12 2:55 ` Jens Axboe [this message]
2019-02-12 3:01 ` Damien Le Moal
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