linux-ext4 - Re: [PATCH] ext4: make huge file flag user visible.

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Message-ID: <20180129230816.GM9359@magnolia>
Date:   Mon, 29 Jan 2018 15:08:16 -0800
From:   "Darrick J. Wong" <darrick.wong@...cle.com>
To:     Tyson Nottingham <tgnottingham@...il.com>
Cc:     linux-ext4@...r.kernel.org, tytso@....edu, adilger.kernel@...ger.ca
Subject: Re: [PATCH] ext4: make huge file flag user visible.

On Wed, Jan 24, 2018 at 11:48:14PM -0800, Tyson Nottingham wrote:
> On Tue, Jan 23, 2018 at 09:09:30PM -0800, Darrick J. Wong wrote:
> 
> > > Pardon my asking, but why is this necessary?  Are there
> > > userspace-visible effects of this flag?
> > 
> > Ahh, the chattr man page says that 'h' means HUGE_FILE_FL, but I guess
> > ext4 won't report it to userspace...?
> > 
> > <shrug> XFS won't either, maybe we just kill the 'h' option? :)
> 
> Thanks for responses. Yes, I was just trying to make ext4 consistent with the
> man page. Since apparently the flag was intended to be user visible at some
> point, I thought it would be fine to make it so. As you said, removing it from
> chattr/lsattr is another option. I'll do whatever I'm told. :)

Ted hasn't replied in a couple of days, but I would surmise from digging
in the ext4 code that we've never exposed the huge file flag to
userspace, so it'd probably be better to withdraw the documentation/code
of the 'h' option from the chattr manpage instead.  ext2/ext3 never had
such a flag at all, so it's unlikely to break anything.

--D

> Tyson