From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48445) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1al2fT-0006mV-6r for qemu-devel@nongnu.org; Tue, 29 Mar 2016 19:03:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1al2fN-0006Pi-S5 for qemu-devel@nongnu.org; Tue, 29 Mar 2016 19:03:21 -0400 Received: from resqmta-po-09v.sys.comcast.net ([96.114.154.168]:46257) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1al2fN-0006PV-Nh for qemu-devel@nongnu.org; Tue, 29 Mar 2016 19:03:17 -0400 From: Eric Blake Date: Tue, 29 Mar 2016 17:00:58 -0600 Message-Id: <1459292460-6875-2-git-send-email-eblake@redhat.com> In-Reply-To: <1459292460-6875-1-git-send-email-eblake@redhat.com> References: <1459173555-4890-1-git-send-email-eblake@redhat.com> <1459292460-6875-1-git-send-email-eblake@redhat.com> Subject: [Qemu-devel] [PATCH v2 1/3] NBD proto: add "Command flags" section List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: nbd-general@lists.sourceforge.net Cc: "Denis V. Lunev" , w@uter.be, qemu-devel@nongnu.org, alex@alex.org.uk, Pavel Borzenkov From: Pavel Borzenkov Add separate "Command flags" section to make it clear which flags are currently defined by the protocol. Signed-off-by: Pavel Borzenkov Reviewed-by: Roman Kagan Signed-off-by: Denis V. Lunev CC: Wouter Verhelst CC: Alex Bligh Message-Id: <1459161798-32120-4-git-send-email-den@openvz.org> [rearrange subsections to parallel Handshake phase, add more details] Signed-off-by: Eric Blake --- 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