From: Pavel Borzenkov <pborzen...@virtuozzo.com> Add separate "Command flags" section to make it clear which flags are currently defined by the protocol.
Signed-off-by: Pavel Borzenkov <pborzen...@virtuozzo.com> Reviewed-by: Roman Kagan <rka...@virtuozzo.com> Signed-off-by: Denis V. Lunev <d...@openvz.org> CC: Wouter Verhelst <w...@uter.be> CC: Alex Bligh <a...@alex.org.uk> Message-Id: <1459161798-32120-4-git-send-email-...@openvz.org> [rearrange subsections to parallel Handshake phase, add more details] Signed-off-by: Eric Blake <ebl...@redhat.com> --- doc/proto.md | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/doc/proto.md b/doc/proto.md index aaae0a2..3d49162 100644 --- a/doc/proto.md +++ b/doc/proto.md @@ -411,6 +411,20 @@ case that data is an error message suitable for display to the user. ### Transmission phase +#### Command flags + +This field of 16 bits is sent by the client with every request and provides +additional information to the server to execute the command. Refer to +the "Request types" section below for more details about how a given flag +affects a particular command. Clients MUST NOT set a command flag bit +that is not documented for the particular command; and whether a flag is +valid may depend on negotiation during the handshake phase. + +- bit 0, `NBD_CMD_FLAG_FUA`; valid during `NBD_CMD_WRITE`. SHOULD be + set to 1 if the client requires "Force Unit Access" mode of + operation. MUST NOT be set unless export flags included + `NBD_FLAG_SEND_FUA`. + #### Request types The following request types exist: -- 2.5.5
