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Date:   Wed, 1 Apr 2020 09:27:44 -0700
From:   Eric Biggers <ebiggers@kernel.org>
To:     David Howells <dhowells@redhat.com>
Cc:     tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org
Subject: Re: Exporting ext4-specific information through fsinfo attributes
Message-ID: <20200401162744.GB201933@gmail.com>
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On Wed, Apr 01, 2020 at 08:39:07AM +0100, David Howells wrote:
> Hi Ted,
> 
> Whilst we were at Vault, I asked you if there was any live ext4 information
> that it could be useful to export through fsinfo().  I've implemented a patch
> that exports six superblock timestamps:
> 
> 	FSINFO_ATTR_EXT4_TIMESTAMPS: 
> 		mkfs    : 2016-02-26 00:37:03
> 		mount   : 2020-03-31 21:57:30
> 		write   : 2020-03-31 21:57:28
> 		fsck    : 2018-12-17 23:32:45
> 		1st-err : -
> 		last-err: -
> 
> but is there anything else that could be of interest?
> 
> Thanks,
> David
> 

FWIW, the filesystem UUID would be useful for testing ext4 and f2fs encryption
(since it's now sometimes used in the derivation of encryption keys).  But I see
you already included it as FSINFO_ATTR_VOLUME_UUID.

- Eric