From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932407Ab0CXRdT (ORCPT ); Wed, 24 Mar 2010 13:33:19 -0400 Received: from mail-bw0-f209.google.com ([209.85.218.209]:35097 "EHLO mail-bw0-f209.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932206Ab0CXRdR (ORCPT ); Wed, 24 Mar 2010 13:33:17 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:from:to:cc:subject:date:message-id:x-mailer; b=N6p6M4TdDM7WQQUNwWLnpvxAT+cVDn5LXBksguoG4FPu8qs5ZotYvGzr725tELkv/K 7GEgSknudqyf6TUuNuWJHNV6Pjh9lhhxb4eX5SdCg6vGRn99cQ0MvmY25xA+Q5nfMONa yAt3sTLtOKGcQoj/JvqT2tunccJmSbgVGb1iw= From: Dmitry Monakhov To: linux-kernel@vger.kernel.org Cc: jens.axboe@oracle.com, hch@infradead.org, mkp@mkp.net, Dmitry Monakhov Subject: [PATCH 0/5] blkdev: discard optimizations v2 RESEND2 Date: Wed, 24 Mar 2010 20:33:03 +0300 Message-Id: <1269451988-5270-1-git-send-email-dmonakhov@openvz.org> X-Mailer: git-send-email 1.6.3.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Wow. lkml seem don't like 'XXX' in the subject So post it one more time. This is second version of generic discard optimizations first was submitted here: http://lwn.net/Articles/373994 Currently there are many file-systems which has implemented discard support, but SSD discs not widely used yet. This patch-set introduce compat helpers which simulate discard requests with zeroing semantics. __blkdev_issue_zeroout: explicitly zeroout given range via write request. blkdev_issue_clear: zeroout given range, use discard request if possible. Later filesystem admin may select which behavior is suitable for his needs discard without zeroing or explicit zeroing even if discard is not supported. Advantages: - Hope that this helps in real filesystem testing. - People who are crazy about data security would be really happy. - Virtual machine developers also would like this feature. Other optimization: - Convert all blkdev_issue_xxx function to common set of flags - Optimize generic discard submitting procedure.