From: Al Viro <viro@ZenIV.linux.org.uk>
Subject: Re: Can one file system be R/W mounted multiple times in Linux?
Date: Fri, 9 Jan 2015 03:51:23 +0000
Message-ID: <20150109035123.GG22149@ZenIV.linux.org.uk>
References: <F792CF86EFE20D4AB8064279AFBA51C61EA72765@SIXPRD3002MB028.064d.mgd.msft.net>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	'linux-ext4' <linux-ext4@vger.kernel.org>,
	"stefanha@redhat.com" <stefanha@redhat.com>
To: Dexuan Cui <decui@microsoft.com>
Return-path: <linux-fsdevel-owner@vger.kernel.org>
Content-Disposition: inline
In-Reply-To: <F792CF86EFE20D4AB8064279AFBA51C61EA72765@SIXPRD3002MB028.064d.mgd.msft.net>
Sender: linux-fsdevel-owner@vger.kernel.org
List-Id: linux-ext4.vger.kernel.org

On Fri, Jan 09, 2015 at 03:44:16AM +0000, Dexuan Cui wrote:
> The 'mount' utility allows me to mount 1 file systems multiple times at different
> mount points, like "mount /dev/sdb1 /a; mount /dev/sdb1 /b".
> 
> I tried to write from /a and /b at the same time and it seems everything is OK
> and no data corruption happens.
> I tried only  ext4 only.
> 
> Can somebody please tell me if this usage is safe?

Yes.