From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33833) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VALzK-00034y-Ug for qemu-devel@nongnu.org; Fri, 16 Aug 2013 11:31:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VALzC-0007Cq-Fw for qemu-devel@nongnu.org; Fri, 16 Aug 2013 11:30:54 -0400 Received: from mail-wg0-x22c.google.com ([2a00:1450:400c:c00::22c]:61110) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VALzC-0007Cl-9c for qemu-devel@nongnu.org; Fri, 16 Aug 2013 11:30:46 -0400 Received: by mail-wg0-f44.google.com with SMTP id l18so1640569wgh.11 for ; Fri, 16 Aug 2013 08:30:45 -0700 (PDT) Date: Fri, 16 Aug 2013 17:30:43 +0200 From: Stefan Hajnoczi Message-ID: <20130816153043.GA24852@stefanha-thinkpad.redhat.com> References: <1374762197-7261-1-git-send-email-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1374762197-7261-1-git-send-email-pbonzini@redhat.com> Subject: Re: [Qemu-devel] [PATCH v3 00/19] Add qemu-img subcommand to dump file metadata List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: kwolf@redhat.com, pl@kamp.de, qemu-devel@nongnu.org, stefanha@redhat.com On Thu, Jul 25, 2013 at 04:22:58PM +0200, Paolo Bonzini wrote: > This series adds a subcommand to "map" that can dump file metadata. > Metadata that is dumped includes: > > - whether blocks are allocated in bs->file and, if so, where > > - whether blocks are zero > > - whether data is read from bs or bs->backing_hd > > Metadata is dumped for an entire chain of images. One example usage is > (for non-compressed, non-encrypted images) to transform the metadata > into a Linux device-mapper setup, and make a qcow2 image available (for > read only) as a block device. Another possible usage is to determine > the used areas of a file, and convert it in place to another format. > Alternatively, the richer data can be used by block jobs to quickly > determine if a block is zero without reading it. > > The patches implement a new operation, bdrv_co_get_block_status, that > supersedes bdrv_co_is_allocated. The bdrv_is_allocated API is still > available of course, and implemented on top of the new operation. > > Patches 1-3 touch cow, which uses bdrv_co_is_allocated during its reads > and writes. I optimized it a bit because it was unbearably slow during > testing. With these patches (also tested with blkverify), booting of > a cow guest image is not particularly slow. > > Patch 4 fixes the bs->total_sectors file size cache, which is used in > bdrv_co_get_block_status to clamp invalid input. > > Patches 5 to 7 clean up the bdrv_is_allocated and bdrv_is_allocated_above > implementation, eliminating some code duplication. > > Patches 8 and 9 tweak bdrv_has_zero_init and its usage in qemu-img in > a way that helps when implementing the new API. > > Patches 10 to 12 implement bdrv_get_block_status and change the formats > to report all the available information. > > Patch 13 and 14 adds the "map" subcommand to qemu-img, and the relevant > documentation. > > Finally, patches 15 to 19 tweak the implementation to extract more > information from protocols, and combine this information with format > metadata whenever possible. > > v2->v3: > new patch 4 to fix qemu-iotests regression > new patch 14 for documentation > > Paolo Bonzini (19): > cow: make reads go at a decent speed > cow: make writes go at a less indecent speed > cow: do not call bdrv_co_is_allocated > block: update bs->total_sectors on writes > block: make bdrv_co_is_allocated static > block: remove bdrv_is_allocated_above/bdrv_co_is_allocated_above > distinction > block: expect errors from bdrv_co_is_allocated > qemu-img: always probe the input image for allocated sectors > block: make bdrv_has_zero_init return false for copy-on-write-images > block: introduce bdrv_get_block_status API > block: define get_block_status return value > block: return get_block_status data and flags for formats > qemu-img: add a "map" subcommand > docs, qapi: document qemu-img map > block: use bdrv_has_zero_init to return BDRV_BLOCK_ZERO > raw-posix: return get_block_status data and flags > raw-posix: detect XFS unwritten extents > block: add default get_block_status implementation for protocols > block: look for zero blocks in bs->file Looking forward to v4 :). It seems there are still some things to tidy up but soon this can be merged. Stefan