From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932329Ab0CXRaF (ORCPT ); Wed, 24 Mar 2010 13:30:05 -0400 Received: from mail-bw0-f209.google.com ([209.85.218.209]:44457 "EHLO mail-bw0-f209.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755694Ab0CXRaA (ORCPT ); Wed, 24 Mar 2010 13:30:00 -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=JYa1R37mqII2qoWUj1z6j5OGnnvklvDFSNLiJHt/6j5HIvdG8m66xwhh//031H6fje exDYWPVfcw9tcmkgJpaILN8t2uOd1os+lbR6AQngLgDaB/NIhJ/AVudc5SIvcqVizKT1 Q80qulZCJY6uS/K/KYYdQkwyI9OPi045BbToM= 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 RESEND Date: Wed, 24 Mar 2010 20:29:46 +0300 Message-Id: <1269451792-5205-1-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 My mail server rejected some messages by unknown reason. 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.