From: Lukas Czerner Subject: Re: [PATCH RFC 00/30] Ext4 snapshots - core patches Date: Mon, 6 Jun 2011 15:08:26 +0200 (CEST) Message-ID: References: <1304959308-11122-1-git-send-email-amir73il@users.sourceforge.net> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: linux-ext4@vger.kernel.org, tytso@mit.edu To: amir73il@users.sourceforge.net Return-path: Received: from mx1.redhat.com ([209.132.183.28]:10358 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752801Ab1FFNIl (ORCPT ); Mon, 6 Jun 2011 09:08:41 -0400 In-Reply-To: <1304959308-11122-1-git-send-email-amir73il@users.sourceforge.net> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, 9 May 2011, amir73il@users.sourceforge.net wrote: > > MERGING > ------- > These patches are based on Ted's current master branch + alloc_semp removal > patches. Although the alloc_semp removal is an independent (and in my eyes > a good) change, it is also required by snapshot patches, to avoid circular > locking dependency during COW allocations. > > Merging with Allison's punch holes patches should be straight forward, since > the hard part, namely Yongqiang's split extent refactoring patches, was > already merged by Ted. > > Merging with Ted's big alloc patches is going to be a bit more challenging, > since big alloc patches make a lot of renaming and refactoring. However, > since has_snapshots and big_alloc features will never work together, > at least testing the code together is not a big concern. Hi Amir, what is the reason for the snapshots to never work with big_alloc ? Just out of curiosity. > > TESTING > ------- > Apart from the extensive testing for the snapshots feature functionality, we > also ran xfstests with snapshots and while taking a snapshot every 1 minute. Since a lot of the tests are actually shorter than one minute, you miss a lot of possible concurrent operations. Is there any reason why not to do it more often ? Let's say every second ? > More importantly, we ran xfstests with snapshots support disabled in compile > time and with snapshot support enabled but without has_snapshot feature. > These xfstests were run with blocksize 1K and 4K and on X86 and X86_64. > The 1K blocksize tests are important for the alloc_semp removal patches. > No problems were found apart from one (test 225 hung), which is already > existing in master branch. > > CREDITS > ------- > The snapshots patches originate in my implementation of the Next3 filesystem > for CTERA networks. > The porting of the Next3 snapshot patches to ext4 patches is attributed to > Aditya Dani, Shardul Mangade, Piyush Nimbalkar and Harshad Shirwadkar from > the Pune Institute of Computer Technology (PICT). > The implementation of extents move-on-write, delayed move-on-write and much > of the cleanup work on these patches was carried out by Yongqiang Yang from > the Institute of Computing Technology, Chinese Academy of Sciences. > > > [PATCH RFC 01/30] ext4: EXT4 snapshots (Experimental) > [PATCH RFC 02/30] ext4: snapshot debugging support > [PATCH RFC 03/30] ext4: snapshot hooks - inside JBD hooks > [PATCH RFC 04/30] ext4: snapshot hooks - block bitmap access > [PATCH RFC 05/30] ext4: snapshot hooks - delete blocks > [PATCH RFC 06/30] ext4: snapshot hooks - move data blocks > [PATCH RFC 07/30] ext4: snapshot hooks - direct I/O > [PATCH RFC 08/30] ext4: snapshot hooks - move extent file data blocks > [PATCH RFC 09/30] ext4: snapshot file > [PATCH RFC 10/30] ext4: snapshot file - read through to block device > [PATCH RFC 11/30] ext4: snapshot file - permissions > [PATCH RFC 12/30] ext4: snapshot file - store on disk > [PATCH RFC 13/30] ext4: snapshot file - increase maximum file size limit to 16TB > [PATCH RFC 14/30] ext4: snapshot block operations > [PATCH RFC 15/30] ext4: snapshot block operation - copy blocks to snapshot > [PATCH RFC 16/30] ext4: snapshot block operation - move blocks to snapshot > [PATCH RFC 17/30] ext4: snapshot control > [PATCH RFC 18/30] ext4: snapshot control - fix new snapshot > [PATCH RFC 19/30] ext4: snapshot control - reserve disk space for snapshot > [PATCH RFC 20/30] ext4: snapshot journaled - increase transaction credits > [PATCH RFC 21/30] ext4: snapshot journaled - implement journal_release_buffer() > [PATCH RFC 22/30] ext4: snapshot journaled - bypass to save credits > [PATCH RFC 23/30] ext4: snapshot journaled - trace COW/buffer credits > [PATCH RFC 24/30] ext4: snapshot list support > [PATCH RFC 25/30] ext4: snapshot race conditions - concurrent COW operations > [PATCH RFC 26/30] ext4: snapshot race conditions - tracked reads > [PATCH RFC 27/30] ext4: snapshot exclude - the exclude bitmap > [PATCH RFC 28/30] ext4: snapshot cleanup > [PATCH RFC 29/30] ext4: snapshot cleanup - shrink deleted snapshots > [PATCH RFC 30/30] ext4: snapshot rocompat - enable rw mount > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > --