[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v3 10/12] block: add backing-file option to bloc
From: |
Eric Blake |
Subject: |
Re: [Qemu-devel] [PATCH v3 10/12] block: add backing-file option to block-stream |
Date: |
Fri, 30 May 2014 15:27:14 -0600 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 |
On 05/30/2014 11:35 AM, Jeff Cody wrote:
> On some image chains, QEMU may not always be able to resolve the
> filenames properly, when updating the backing file of an image
> after a block job.
>
> For instance, certain relative pathnames may fail, or drives may
> have been specified originally by file descriptor (e.g. /dev/fd/???),
> or a relative protocol pathname may have been used.
>
> In these instances, QEMU may lack the information to be able to make
> the correct choice, but the user or management layer most likely does
> have that knowledge.
>
> With this extension to the block-stream api, the user is able to change
> the backing file of the active layer as part of the block-stream
> operation.
>
> This allows the change to be 'safe', in the sense that if the attempt
> to write the active image metadata fails, then the block-stream
> operation returns failure, without disrupting the guest.
>
> If a backing file string is not specified in the command, the backing
> file string to use is determined in the same manner as it was
> previously.
>
> Signed-off-by: Jeff Cody <address@hidden>
> ---
> block/stream.c | 11 +++++------
> blockdev.c | 12 ++++++++++++
> hmp.c | 3 ++-
> qapi-schema.json | 18 +++++++++++++++++-
> qmp-commands.hx | 2 +-
> 5 files changed, 37 insertions(+), 9 deletions(-)
>
Reviewed-by: Eric Blake <address@hidden>
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
signature.asc
Description: OpenPGP digital signature
- [Qemu-devel] [PATCH v3 01/12] block: Auto-generate node_names for each BDS entry, (continued)
- [Qemu-devel] [PATCH v3 01/12] block: Auto-generate node_names for each BDS entry, Jeff Cody, 2014/05/30
- [Qemu-devel] [PATCH v3 02/12] block: add helper function to determine if a BDS is in a chain, Jeff Cody, 2014/05/30
- [Qemu-devel] [PATCH v3 03/12] block: Add overlay BDS pointer into the BlockDriverState struct, Jeff Cody, 2014/05/30
- [Qemu-devel] [PATCH v3 04/12] block: add helper function to find the active layer of any BDS, Jeff Cody, 2014/05/30
- [Qemu-devel] [PATCH v3 05/12] block: simplify bdrv_find_base(), Jeff Cody, 2014/05/30
- [Qemu-devel] [PATCH v3 06/12] block: make 'top' argument to block-commit optional, Jeff Cody, 2014/05/30
- [Qemu-devel] [PATCH v3 07/12] block: Accept node-name arguments for block-commit, Jeff Cody, 2014/05/30
- [Qemu-devel] [PATCH v3 08/12] block: extend block-commit to accept a string for the backing file, Jeff Cody, 2014/05/30
- [Qemu-devel] [PATCH v3 10/12] block: add backing-file option to block-stream, Jeff Cody, 2014/05/30
- Re: [Qemu-devel] [PATCH v3 10/12] block: add backing-file option to block-stream,
Eric Blake <=
- [Qemu-devel] [PATCH v3 09/12] block: add ability for block-stream to use node-name, Jeff Cody, 2014/05/30
- [Qemu-devel] [PATCH v3 11/12] block: Add QMP documentation for block-stream, Jeff Cody, 2014/05/30
- [Qemu-devel] [PATCH v3 12/12] block: add QAPI command to allow live backing file change, Jeff Cody, 2014/05/30