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Date: Tue, 26 Sep 2017 07:04:25 +0800
From: Ming Lei <ming.lei@redhat.com>
To: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org,
	Christoph Hellwig <hch@lst.de>,
	"Martin K . Petersen" <martin.petersen@oracle.com>,
	=Oleksandr Natalenko <oleksandr@natalenko.name>,
	Shaohua Li <shli@kernel.org>, linux-raid@vger.kernel.org,
	Hannes Reinecke <hare@suse.com>,
	Johannes Thumshirn <jthumshirn@suse.de>
Subject: Re: [PATCH v4 1/7] md: Make md resync and reshape threads freezable
Message-ID: <20170925230421.GD18137@ming.t460p>
References: <20170925202924.16603-1-bart.vanassche@wdc.com>
 <20170925202924.16603-2-bart.vanassche@wdc.com>
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In-Reply-To: <20170925202924.16603-2-bart.vanassche@wdc.com>
List-ID: <linux-block@vger.kernel.org>

On Mon, Sep 25, 2017 at 01:29:18PM -0700, Bart Van Assche wrote:
> Some people use the md driver on laptops and use the suspend and
> resume functionality. Since it is essential that submitting of
> new I/O requests stops before device quiescing starts, make the
> md resync and reshape threads freezable.

As I explained, if SCSI quiesce is safe, this patch shouldn't
be needed.

The issue isn't MD specific, and in theory can be triggered
on all devices. And you can see the I/O hang report on BTRFS(RAID)
without MD involved:

	https://marc.info/?l=linux-block&m=150634883816965&w=2

So please remove this patch from the patchset.

--
Ming