block: Document that x-blockdev-change breaks quorum children list

Removing a quorum child node with x-blockdev-change results in a quorum
driver state that cannot be recreated with create options because it
would require a list with gaps. This causes trouble in at least
.bdrv_refresh_filename().

Document this problem so that we won't accidentally mark the command
stable without having addressed it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
This commit is contained in:
Kevin Wolf 2017-12-15 11:54:22 +01:00
parent 546a7dc40e
commit 6b4738ce4d

View File

@ -3918,6 +3918,10 @@
# does not support all kinds of operations, all kinds of children, nor
# all block drivers.
#
# FIXME Removing children from a quorum node means introducing gaps in the
# child indices. This cannot be represented in the 'children' list of
# BlockdevOptionsQuorum, as returned by .bdrv_refresh_filename().
#
# Warning: The data in a new quorum child MUST be consistent with that of
# the rest of the array.
#