From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?B?SsO2cm4=?= Engel Subject: Re: [RFC] TileFS - a proposal for scalable integrity checking Date: Sun, 29 Apr 2007 17:58:48 +0200 Message-ID: <20070429155847.GC30608@lazybastard.org> References: <20070428220522.GN11166@waste.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-fsdevel@vger.kernel.org To: Matt Mackall Return-path: Received: from lazybastard.de ([212.112.238.170]:49350 "EHLO longford.lazybastard.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756509AbXD2QCu (ORCPT ); Sun, 29 Apr 2007 12:02:50 -0400 Content-Disposition: inline In-Reply-To: <20070428220522.GN11166@waste.org> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Sat, 28 April 2007 17:05:22 -0500, Matt Mackall wrote: >=20 > Some things we need to check during fsck: >=20 > all directories point to in-use inodes > all in-use inodes are referred to by directories > all inodes in use are marked in use > all free inodes are marked free > all inodes point to in-use blocks > all inode refcounts are correct > all inode block counts are correct > free inode count is correct >=20 > no blocks are used twice > all used blocks are marked as used > all free blocks are marked as free > optional: all block contents are correct statfs information matches filesystem content This one may still require a full fsck in your current approach. One i= f the good aspects of ChunkFS (assuming my understanding matches reality) is to have per-chunk counters for free blocks, free inodes, etc. For a fast fsck you would need to have these counters per-unit as well. It doesn't matter whether your unit is a tile, chunk, blockgroup or karboozel. Having some tree structure for these counters would also help. Statfs requires to add all counters for all units. Smaller units speed up fsc= k but slow down statfs. With a tree statfs can be O(log(n)). J=C3=B6rn --=20 "Translations are and will always be problematic. They inflict violence upon two languages." (translation from German) - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html