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From: Matthew Wilcox <willy@infradead.org>
To: James Bottomley <James.Bottomley@hansenpartnership.com>
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, 5 Jul 2019 10:39:06 -0700	[thread overview]
Message-ID: <20190705173905.GA32320@bombadil.infradead.org> (raw)
In-Reply-To: <1562343948.2953.8.camel@HansenPartnership.com>

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.

  reply	other threads:[~2019-07-05 17:39 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 [this message]
2019-07-05 18:49               ` James Bottomley
2019-07-05 21:40                 ` Darrick J. Wong
2019-07-06  4:02                 ` Theodore Ts'o

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