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Date: Mon, 24 Aug 2015 09:29:29 +0800
From: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
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To: Richard Weinberger <richard@nod.at>, <viro@ZenIV.linux.org.uk>,
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Subject: Re: [PATCH v2 23/35] ubifs: set/clear MS_RDONLY properly in
 ubifs_remount
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On 08/10/2015 10:46 AM, Dongsheng Yang wrote:
> On 08/09/2015 05:17 AM, Richard Weinberger wrote:
>> Am 30.07.2015 um 07:48 schrieb Dongsheng Yang:
>>> We need to set or clear MS_RDONLY in remounting.
>>
>> Care to explain why?
>> Does the quota subsystem need that information?
>> If so, where?
>
> Ha, yes, you are right.
>
> When we remount to rw from ro, we need to call dquot_resume.
> And dquot_resume will call vfs_load_quota_inode() which
> will check the MS_RDONLY. If it's ro mode, will return
> an -EROFS.
>
> And I know that we are using ->ro_mount in ubifs
> to store the mounted mode. So we don't care about
> the MS_RDONLY in ubifs. But why not to tell vfs we are in
> ro or rw? Does it cause any problem?

Hi Artem,
	I found there is a commit 2ef13294d to introduce
ro_mount to ubifs. Yes, I see the reason to use ro_mount
rather than MS_RDONLY in ubifs. But why we do not set
MS_RDONLY to tell vfs it's in rdonly or not? Current
quota depends on it. Does this patch cause some problem?

Yang
>
> Thanx
> YAng
>
>> Thanks,
>> //richard
>> .
>>
>
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