From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: Theodore Ts'o <tytso@mit.edu>,
linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Parisc List <linux-parisc@vger.kernel.org>
Subject: Re: Question about ext4 testing: need to produce a high depth extent tree to verify mapping code
Date: Fri, 05 Jul 2019 11:49:02 -0700 [thread overview]
Message-ID: <1562352542.2953.10.camel@HansenPartnership.com> (raw)
In-Reply-To: <20190705173905.GA32320@bombadil.infradead.org>
On Fri, 2019-07-05 at 10:39 -0700, Matthew Wilcox wrote:
> On Fri, Jul 05, 2019 at 09:25:48AM -0700, James Bottomley wrote:
> > Now the problem: I'd like to do some testing with high depth extent
> > trees to make sure I got this right, but the files we load at boot
> > are ~20MB in size and I'm having a hard time fragmenting the
> > filesystem enough to produce a reasonable extent (I've basically
> > only got to a two level tree with two entries at the top). Is
> > there an easy way of producing a high depth extent tree for a 20MB
> > file?
>
> Create a series of 4kB files numbered sequentially, each 4kB in size
> until you fill the partition. Delete the even numbered ones. Create
> a 20MB file.
Well, I know *how* to do it ... I was just hoping, in the interests of
creative laziness, that someone else had produced a script for this
before I had to ... particularly one which leaves more randomized gaps.
James
next prev parent reply other threads:[~2019-07-05 18:49 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-01 22:44 [BUG] mke2fs produces corrupt filesystem if badblock list contains a block under 251 James Bottomley
2019-07-02 0:23 ` Theodore Ts'o
2019-07-02 0:53 ` James Bottomley
2019-07-02 17:33 ` Theodore Ts'o
2019-07-02 19:31 ` James Bottomley
2019-07-02 20:39 ` Theodore Ts'o
2019-07-03 0:37 ` James Bottomley
2019-07-05 16:25 ` Question about ext4 testing: need to produce a high depth extent tree to verify mapping code James Bottomley
2019-07-05 17:39 ` Matthew Wilcox
2019-07-05 18:49 ` James Bottomley [this message]
2019-07-05 21:40 ` Darrick J. Wong
2019-07-06 4:02 ` Theodore Ts'o
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