lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Tue, 18 Sep 2012 00:10:06 -0400
From:	Theodore Ts'o <>
To:	Andrey Sidorov <>
Subject: Re: [PATCH RFC 1/2] ext4: speed-up truncate/unlink

On Tue, Sep 18, 2012 at 01:00:30AM +0400, Andrey Sidorov wrote:
> Do not iterate over data blocks scanning for bh's to forget as they're
> never exist. This improves time taken by unlink / truncate syscall.
> Tested by continuously truncating file that is being written by dd.
> Another test is rm -rf of linux tree while tar unpacks it. With
> ordered data mode condition unlikely(!tbh) was always met in
> ext4_free_blocks. With journal data mode tbh was found only few times,
> so optimisation is also possible.

Thanks for this patch.  It's good you did the testing, although from a
theoretical point of view I'm sure it's sound because the only case
where journal=data mode will there be data blocks in the buffer cache.
In the other cases, the data is cached in the page cache, so it's a
waste of time looking up the blocks so they can be bforgotten.

The one thing which is missing from your patch is a Signed-off-by:
footer.  This has a specific legal meaning.  See:

You don't need to resend this patch, though; just reply with an
acknowledgement that you agree to add your DCO to the patch:

Signed-off-by: Andrey Sidorov <>

Thanks for contributing to the ext4 file system!

						- Ted
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists