diff options
| author | Max Reitz <mreitz@redhat.com> | 2019-06-11 21:19:26 +0200 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2020-09-07 12:31:31 +0200 |
| commit | 05ea385afdfe5d0886265880bfd14d17192beb03 (patch) | |
| tree | c4fa1cb6bf4cdf5be2e4349c139b46791e3a7ab1 /qapi/block-core.json | |
| parent | f1a7f18f07ef41b4d078621bd6e515165106d91f (diff) | |
blockdev: Fix active commit choice
We have to perform an active commit whenever the top node has a parent
that has taken the WRITE permission on it.
This means that block-commit's @backing-file parameter is no longer
allowed for such nodes, and that users will have to issue a
block-job-complete command. Neither should pose a problem in practice,
because this case was basically just broken until now.
(Since this commit already touches block-commit's documentation, it also
moves up the chunk explaining general block-commit behavior that for
some reason was situated under @backing-file.)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'qapi/block-core.json')
| -rw-r--r-- | qapi/block-core.json | 39 |
1 files changed, 20 insertions, 19 deletions
diff --git a/qapi/block-core.json b/qapi/block-core.json index e34796d98f..0345f6f2d2 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -1569,6 +1569,18 @@ # Live commit of data from overlay image nodes into backing nodes - i.e., # writes data between 'top' and 'base' into 'base'. # +# If top == base, that is an error. +# If top has no overlays on top of it, or if it is in use by a writer, +# the job will not be completed by itself. The user needs to complete +# the job with the block-job-complete command after getting the ready +# event. (Since 2.0) +# +# If the base image is smaller than top, then the base image will be +# resized to be the same size as top. If top is smaller than the base +# image, the base will not be truncated. If you want the base image +# size to match the size of the smaller top, you can safely truncate +# it yourself once the commit operation successfully completes. +# # @job-id: identifier for the newly-created block job. If # omitted, the device name will be used. (Since 2.7) # @@ -1593,14 +1605,15 @@ # accepted # # @backing-file: The backing file string to write into the overlay -# image of 'top'. If 'top' is the active layer, -# specifying a backing file string is an error. This -# filename is not validated. +# image of 'top'. If 'top' does not have an overlay +# image, or if 'top' is in use by a writer, specifying +# a backing file string is an error. # -# If a pathname string is such that it cannot be -# resolved by QEMU, that means that subsequent QMP or -# HMP commands must use node-names for the image in -# question, as filename lookup methods will fail. +# This filename is not validated. If a pathname string +# is such that it cannot be resolved by QEMU, that +# means that subsequent QMP or HMP commands must use +# node-names for the image in question, as filename +# lookup methods will fail. # # If not specified, QEMU will automatically determine # the backing file string to use, or error out if @@ -1609,18 +1622,6 @@ # filename or protocol. # (Since 2.1) # -# If top == base, that is an error. -# If top == active, the job will not be completed by itself, -# user needs to complete the job with the block-job-complete -# command after getting the ready event. (Since 2.0) -# -# If the base image is smaller than top, then the base image -# will be resized to be the same size as top. If top is -# smaller than the base image, the base will not be -# truncated. If you want the base image size to match the -# size of the smaller top, you can safely truncate it -# yourself once the commit operation successfully completes. -# # @speed: the maximum speed, in bytes per second # # @on-error: the action to take on an error. 'ignore' means that the request |