[using the updated nbd list email]
On 02/14/2018 08:35 AM, Vladimir Sementsov-Ogievskiy wrote:
Just note: looks like we allow zero-sized metadata context name. Is it ok?
A description of a metadata context. Data:
o 32 bits, NBD metadata context ID.
o String, name of the metadata context. This is not required to be
a human-readable string, but it MUST be valid UTF-8 data.
No; elsewhere we state:
Metadata contexts are identified by their names. The name MUST consist of a
namespace, followed by a colon, followed by a leaf-name. The namespace must
consist entirely of printable non-whitespace UTF-8 characters other than
colons, and be non-empty. The entire name (namespace, colon, and leaf-name)
MUST follow the restrictions for strings as laid out earlier in this document.
Namespaces MUST be consist of one of the following:
base, for metadata contexts defined by this document;
nbd-server, for metadata contexts defined by the implementation that
accompanies this document (none currently);
x-*, where * can be replaced by an arbitrary string not containing colons,
for local experiments. This SHOULD NOT be used by metadata contexts that are
expected to be widely used.
A third-party namespace from the list below.
So a name must be at least 2 bytes (for a one-byte namespace, if someone
ever registers one - and supposing that namespace has zero-byte leaf
names), but will more commonly be even longer.
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
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