On 08/10/2018 11:26 AM, Kevin Wolf wrote:
The block-commit QMP command required specifying the top and base nodes
of the commit jobs using the file name of that node. While this works
in simple cases (local files with absolute paths), the file names
generated for more complicated setups can be hard to predict.
This adds two new options top-node and base-node to the command, which
allow specifying node names instead. They are mutually exclusive with
the old options.
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
qapi/block-core.json | 24 ++++++++++++++++++------
blockdev.c | 32 ++++++++++++++++++++++++++++++--
2 files changed, 48 insertions(+), 8 deletions(-)
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 5b9084a394..91dd075c84 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -1455,12 +1455,23 @@
#
# @device: the device name or node-name of a root node
#
-# @base: The file name of the backing image to write data into.
-# If not specified, this is the deepest backing image.
+# @base-node: The node name of the backing image to write data into.
+# If not specified, this is the deepest backing image.
+# (since: 2.10)
I'd word this as (since 3.1)...
#
-# @top: The file name of the backing image within the image chain,
-# which contains the topmost data to be committed down. If
-# not specified, this is the active layer.
+# @base: Same as @base-node, except that it is a file name rather than a node
+# name. This must be the exact filename string that was used to open the
+# node; other strings, even if addressing the same file, are not
+# accepted (deprecated, use @base-node instead)
...and this as (since 2.10). When we finish the deprecation and remove
@base, then we might consolidate the 'since' documentation at that time,
but until then, I think listing the two separate releases gives users an
idea of how far back they might have been using the deprecated code, and
when the preferred form was introduced.
+#
+# @top-node: The node name of the backing image within the image chain
+# which contains the topmost data to be committed down. If
+# not specified, this is the active layer. (since: 2.10)
+#
+# @top: Same as @top-node, except that it is a file name rather than a node
+# name. This must be the exact filename string that was used to open the
+# node; other strings, even if addressing the same file, are not
+# accepted (deprecated, use @base-node instead)
Likewise.
Actually, do we NEED new arguments? Can we just make @base and @top
accept either an exact file name OR a node name? On the other hand, new
arguments are introspectible, overloading the old argument to take two
forms is not. So that doesn't help :(
Or, here's an idea:
Keep the name @base and @top, but add a new '*by-node':'bool' parameter,
defaulting to false for now, but perhaps with a deprecation warning that
we'll switch the default to true in one release and delete the parameter
altogether in an even later release. When false, @base and @top are
filenames, as before; when true, @base and @top are node names instead.
Introspectible, nicer names in the long run, and avoids having to detect
a user providing two mutually-exclusive options at once.
+++ b/blockdev.c
@@ -3308,7 +3308,9 @@ out:
}
void qmp_block_commit(bool has_job_id, const char *job_id, const char *device,
+ bool has_base_node, const char *base_node,
bool has_base, const char *base,
+ bool has_top_node, const char *top_node,
bool has_top, const char *top,
bool has_backing_file, const char *backing_file,
bool has_speed, int64_t speed,
Getting to be a long signature. Should we use 'boxed':true in the QAPI
file to make this easier to write? (Separate commit)
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
