On Sun, Jul 29, 2012 at 6:28 AM, Jeff Layton <jlayton@xxxxxxxxx> wrote: > On Sat, 28 Jul 2012 08:19:48 -0700 > Richard Sharpe <realrichardsharpe@xxxxxxxxx> wrote: > >> Hi folks, >> >> I have started looking at implementing some of the SMB3.0 features. >> This is because, in order to do SMB Direct I need multi-connect. >> >> In reading the latest version of the spec ([MS-SMB2] dated July 5, >> 2012 and available from msdn.microsoft.com) I notice that each session >> should have a channel list, which is a list of objects containing a >> connection reference and a signing key. It also should have a channel >> sequence number. >> >> This means that I will need to change the struct cifs_ses to have a >> channel list rather than a struct TCP_Server_Info. >> >> In addition, multi-connect allows multiple connections to the same >> actual server, since it allows a session to use multiple TCP >> connection on a GbE or 10GbE link. So, it seems that I will need to >> introduce an explicit notion of a connection, which the code does not >> currently have. This will definitely be needed for SMB Direct, because >> the model is that you establish a connection to the server on TCP, >> negotiate a protocol and then establish a session and then send an >> FSCTL to discover the (common) set of interfaces the server has. After >> that, if you notice that the client and server have an RDMA-capable >> interface in common, you establish a connection via that interface, >> negotiate protocol and then create a session (session setup) but bind >> it to the existing session. >> >> Does anyone have any comments at this stage? This seems like a >> significant undertaking :-) >> > > It sounds like you're on the right track. Essentially I think you need > to abstract out the parts of the TCP_Server_Info that are specific to > the socket, and put them in a new struct that will hang off of the > TCP_Server_Info in some way (maybe a linked list of "smb_connection" > structs?) Hmmm, actually, I think that the TCP_Server_Info should be renamed cifs_tcp_connection or something like that. Then 3.2.1.3 of [MS-SMB2] says that if the client implements version 2.2/3.0 of SMB2, it should also have a ChannelList (an array/list of connection and SigningKey pairs) a ChannelSequence and a few other bits. Of course, these are only relevant if you are talking to a server that implements the 2.2/3.0 dialect of SMB2. So, I need to think about how to deal with this. Then I need to think about how to handle Infiniband Connection objects because they have a little protocol of their own, so they need a proto_ops structure, while a TCP connection already has that. Then, there is the issue of using socket callbacks for TCP. Infiniband is event driven, and I need to look at the model to see if we can unify socket callbacks and Infiniband events, which use callbacks. -- Regards, Richard Sharpe (何以解憂？唯有杜康。--曹操) -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
