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  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, 5 May 2015 10:20:25 -0400
From:	Theodore Ts'o <>
To:	"Darrick J. Wong" <>
Subject: Re: [PATCH 10/35] undo-io: add new calls to and speed up the undo io

On Wed, Apr 01, 2015 at 07:35:06PM -0700, Darrick J. Wong wrote:
> Implement pass-through calls for discard, zero-out, and readahead in
> the IO manager so that we can take advantage of any underlying
> support.
> Furthermore, improve tdb write-out speed by disabling locking and only
> fsyncing at the end -- we don't care about locking because having
> multiple writers to the undo file will produce an undo database full
> of garbage blocks; and we only need to fsync at the end because if we
> fail before the end, our undo file will lack the necessary superblock
> data that e2undo requires to do replay safely.  Without this, we call
> fsync four times per tdb update(!)  This reduces the overhead of using
> undo_io while converting a 2TB FS to metadata_csum from 3+ hours to 55
> minutes.
> Signed-off-by: Darrick J. Wong <>

Thanks, applied.

					- 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