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Subject: Re: [BUG] mke2fs produces corrupt filesystem if badblock list
 contains a block under 251
From:   James Bottomley <James.Bottomley@HansenPartnership.com>
To:     Theodore Ts'o <tytso@mit.edu>
Cc:     linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        Parisc List <linux-parisc@vger.kernel.org>
Date:   Tue, 02 Jul 2019 17:37:32 -0700
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On Tue, 2019-07-02 at 16:39 -0400, Theodore Ts'o wrote:
> On Tue, Jul 02, 2019 at 12:31:34PM -0700, James Bottomley wrote:
> > Actually, this is giving me:
> > 
> > mke2fs: Operation not supported for inodes containing extents while
> > creating huge files
> > 
> > Is that because it's an ext4 only feature?
> 
> That'll teach me not to send out a sequence like that without testing
> it myself first.  :-)

Heh, join the club ... it has a very large membership ... I've got a
frequent flier card for it ...

> Yeah, because one of the requirements was to make the file
> contiguous, without any intervening indirect block or extent tree
> blocks, the creation of the file is done manually, and at the time, I
> only implemented it for extents, since the original goal of the goal
> was to create really big files (hence the name of the feature
> "mk_hugefile"), and using indirect blocks would be a huge waste of
> disk space.

I guessed as much.

> It wouldn't be that hard for me to add support for indirect block
> maps, or if you were going to convert things over so that the pa_risc
> 2nd stage boot loader can understand how to read from extents,
> that'll allow this to work as well.

Let me look at it.  I think I can just take routines out of lib/ext2fs
and graft them into the IPL, but our own home grown ext2/3 handling
routines are slightly eccentric so it's not as simple as that.

James