All of lore.kernel.org
 help / color / mirror / Atom feed
From: Theodore Tso <tytso@mit.edu>
To: Thomas Glanzmann <thomas@glanzmann.de>,
	Arjan van de Ven <arjan@infradead.org>,
	tytso@thunk.org, LKML <linux-kernel@vger.kernel.org>,
	linux-ext4@vger.kernel.org
Subject: Re: zero out blocks of freed user data for operation a virtual machine environment
Date: Mon, 25 May 2009 08:03:20 -0400	[thread overview]
Message-ID: <20090525120320.GA25908@mit.edu> (raw)
In-Reply-To: <20090524173933.GD24753@cip.informatik.uni-erlangen.de>

On Sun, May 24, 2009 at 07:39:33PM +0200, Thomas Glanzmann wrote:
> Hello,
> 
> > > tunable feature that zeroes our free data
> 
> > wouldn't it be better if the VM's would just support the TRIM command?
> 
> the resources available to me indicate that the TRIM command is a not
> yet standarized command targeted at SSD disks to indicate free disk
> space. Does ext3/4 trigger a block device layer call that could result
> in a TRIM command?

Yes, it does, sb_issue_discard().  So if you wanted to hook into this
routine with a function which issued calls to zero out blocks, it
would be easy to create a private patch.

					- Ted

  reply	other threads:[~2009-05-25 12:03 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-24 17:00 zero out blocks of freed user data for operation a virtual machine environment Thomas Glanzmann
2009-05-24 17:15 ` Arjan van de Ven
2009-05-24 17:39   ` Thomas Glanzmann
2009-05-25 12:03     ` Theodore Tso [this message]
2009-05-25 12:34       ` Thomas Glanzmann
2009-05-25 13:14         ` Goswin von Brederlow
2009-05-25 14:01           ` Thomas Glanzmann
     [not found]           ` <f3177b9e0905251023n762b815akace1ae34e643458e@mail.gmail.com>
2009-05-25 17:26             ` Chris Worley
2009-05-25 17:26               ` Chris Worley
2009-05-26 10:22             ` Goswin von Brederlow
2009-05-26 10:22               ` Goswin von Brederlow
2009-05-26 16:52               ` Chris Worley
2009-05-26 16:52                 ` Chris Worley
2009-05-28 19:27                 ` Goswin von Brederlow
2009-05-28 19:27                   ` Goswin von Brederlow
2009-05-25  3:29 ` David Newall
2009-05-25  5:26   ` Thomas Glanzmann
2009-05-25  7:48 ` Ron Yorston
2009-05-25 10:50   ` Thomas Glanzmann
2009-05-25 12:06 ` Theodore Tso
2009-05-25 21:19 ` Bill Davidsen
2009-05-26  4:45   ` Thomas Glanzmann

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20090525120320.GA25908@mit.edu \
    --to=tytso@mit.edu \
    --cc=arjan@infradead.org \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=thomas@glanzmann.de \
    --cc=tytso@thunk.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.