From: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Create the BlockdevOptionsCor structure for COR driver specific options
splitting it off form the BlockdevOptionsGenericFormat. The only option
'bottom' node in the structure denotes an image file that limits the
COR operations in the backing chain.
We are going to use the COR-filter for a block-stream job and will pass
a bottom node name to the COR driver. The bottom node is the first
non-filter overlay of the base. It was introduced because the base node
itself may change due to possible concurrent jobs.
Suggested-by: Max Reitz <mreitz@redhat.com>
Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
[vsementsov: fix bdrv_is_allocated_above() usage]
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
qapi/block-core.json | 21 +++++++++++++++-
block/copy-on-read.c | 57 ++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 75 insertions(+), 3 deletions(-)
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 8ef3df6767..04055ef50c 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -3942,6 +3942,25 @@
'data': { 'throttle-group': 'str',
'file' : 'BlockdevRef'
} }
+
+##
+# @BlockdevOptionsCor:
+#
+# Driver specific block device options for the copy-on-read driver.
+#
+# @bottom: the name of a non-filter node (allocation-bearing layer) that limits
+# the COR operations in the backing chain (inclusive).
@@ -51,7 +56,17 @@ static int cor_open(BlockDriverState *bs, QDict *options,
int flags,
((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
bs->file->bs->supported_zero_flags);
+ if (bottom_node) {
+ bottom_bs = bdrv_lookup_bs(NULL, bottom_node, errp);
+ if (!bottom_bs) {
+ error_setg(errp, "Bottom node '%s' not found", bottom_node);
+ qdict_del(options, "bottom");
+ return -EINVAL;
+ }