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From:   OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
To:     Christoph Hellwig <hch@infradead.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH] fat: Add nobarrier to workaround the strange behavior of device
References: <871rzdrdxw.fsf@mail.parknet.co.jp>
        <20190628143216.GA538@infradead.org>
Date:   Sat, 29 Jun 2019 00:03:46 +0900
In-Reply-To: <20190628143216.GA538@infradead.org> (Christoph Hellwig's message
        of "Fri, 28 Jun 2019 07:32:16 -0700")
Message-ID: <87pnmxpx9p.fsf@mail.parknet.co.jp>
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Christoph Hellwig <hch@infradead.org> writes:

> On Fri, Jun 28, 2019 at 11:18:19PM +0900, OGAWA Hirofumi wrote:
>> To workaround those devices and provide flexibility, this adds
>> "barrier"/"nobarrier" mount options to fat driver.
>
> We have deprecated these rather misnamed options, and now instead allow
> tweaking the 'cache_type' attribute on the SCSI device.

I see, sounds like good though. Does it work for all stable versions?
Can it disable only flush command without other effect? And it would be
better to be normal user controllable easily.

This happened on normal user's calibre app that mount via udisks.  With
this option, user can workaround with /etc/fstab for immediate users.

> That being said if the device behave this buggy you should also report
> it to to the usb-storage and scsi maintainers so that we can add a
> quirk for it.

It might not be able to say as buggy simply. The device looks work if no
idle and not hit pattern of usage, so quirk can be overkill.

Anyway, I don't have the device, if you can get the device and
investigate, it can be fine.

Thanks.
-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>