diff options
| author | Jeff Cody <jcody@redhat.com> | 2014-07-01 09:52:16 +0200 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2014-07-01 10:46:38 +0200 |
| commit | fa40e65622352012dccd435147f28161375a6815 (patch) | |
| tree | ae1694c491dc6a2f5737939e829dc9ccc95f232b /qapi | |
| parent | 4e855baabfb548067b618808c32dc413d40e0bc7 (diff) | |
block: add QAPI command to allow live backing file change
This allows a user to make a live change to the backing file recorded in
an open image.
The image file to modify can be specified 2 ways:
1) image filename
2) image node-name
Note: this does not cause the backing file itself to be reopened; it
merely changes the backing filename in the image file structure, and
in internal BDS structures.
It is the responsibility of the user to pass a filename string that
can be resolved when the image chain is reopened, and the filename
string is not validated.
A good analogy for this command is that it is a live version of
'qemu-img rebase -u', with respect to changing the backing file string.
[Jeff is offline so I respun this patch in his absence. Dropped image
filename since using node-name is preferred and this is a new command.
No need to introduce the limitations of finding images by filename.
--Stefan]
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'qapi')
| -rw-r--r-- | qapi/block-core.json | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/qapi/block-core.json b/qapi/block-core.json index 6a697f1458..aa1252778c 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -680,6 +680,32 @@ 'data': 'BlockdevSnapshot' } ## +# @change-backing-file +# +# Change the backing file in the image file metadata. This does not +# cause QEMU to reopen the image file to reparse the backing filename +# (it may, however, perform a reopen to change permissions from +# r/o -> r/w -> r/o, if needed). The new backing file string is written +# into the image file metadata, and the QEMU internal strings are +# updated. +# +# @image-node-name: The name of the block driver state node of the +# image to modify. +# +# @device: The name of the device that owns image-node-name. +# +# @backing-file: The string to write as the backing file. This +# string is not validated, so care should be taken +# when specifying the string or the image chain may +# not be able to be reopened again. +# +# Since: 2.1 +## +{ 'command': 'change-backing-file', + 'data': { 'device': 'str', 'image-node-name': 'str', + 'backing-file': 'str' } } + +## # @block-commit # # Live commit of data from overlay image nodes into backing nodes - i.e., |