From: "Labiaga, Ricardo" Subject: RE: [pnfs] [RFC 09/39] nfs41: New xs_tcp_read_data() Date: Fri, 5 Jun 2009 09:44:55 -0700 Message-ID: <273FE88A07F5D445824060902F7003440612B810@SACMVEXC1-PRD.hq.netapp.com> References: <1244144425.5203.83.camel@heimdal.trondhjem.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: , To: "Myklebust, Trond" , "Benny Halevy" Return-path: Received: from mx2.netapp.com ([216.240.18.37]:32169 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751889AbZFEQrk convert rfc822-to-8bit (ORCPT ); Fri, 5 Jun 2009 12:47:40 -0400 In-Reply-To: <1244144425.5203.83.camel-rJ7iovZKK19ZJLDQqaL3InhyD016LWXt@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: > -----Original Message----- > From: Myklebust, Trond > Sent: Thursday, June 04, 2009 12:40 PM > To: Benny Halevy > Cc: linux-nfs@vger.kernel.org; pnfs@linux-nfs.org > Subject: Re: [pnfs] [RFC 09/39] nfs41: New xs_tcp_read_data() > > On Fri, 2009-05-01 at 02:20 +0300, Benny Halevy wrote: > > From: Ricardo Labiaga > > > > Handles RPC replies and backchannel callbacks. Traditionally the NFS > > client has expected only RPC replies on its open connections. With > > NFSv4.1, callbacks can arrive over an existing open connection. > > > > This patch refactors the old xs_tcp_read_request() into an RPC reply > handler: > > xs_tcp_read_reply(), a new backchannel callback handler: > xs_tcp_read_callback(), > > and a common routine to read the data off the transport: > xs_tcp_read_common(). > > The new xs_tcp_read_callback() queues callback requests onto a queue > where > > the callback service (a separate thread) is listening for the > processing. > > > > This patch incorporates work and suggestions from Rahul Iyer > (iyer@netapp.com) > > and Benny Halevy (bhalevy@panasas.com). > > > > [nfs41: Keep track of RPC call/reply direction with a flag] > > [nfs41: Preallocate rpc_rqst receive buffer for handling callbacks] > > Signed-off-by: Ricardo Labiaga > > Signed-off-by: Benny Halevy > > --- > > net/sunrpc/xprtsock.c | 141 > ++++++++++++++++++++++++++++++++++++++++++------ > > 1 files changed, 123 insertions(+), 18 deletions(-) > > > > diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c > > index 692b517..403ebda 100644 > > --- a/net/sunrpc/xprtsock.c > > +++ b/net/sunrpc/xprtsock.c > > @@ -34,6 +34,9 @@ > > #include > > #include > > #include > > +#ifdef CONFIG_NFS_V4_1 > > +#include > > +#endif > > > > #include > > #include > > @@ -1028,25 +1031,16 @@ static inline void xs_tcp_read_calldir(struct > sock_xprt *transport, > > xs_tcp_check_fraghdr(transport); > > } > > > > -static inline void xs_tcp_read_request(struct rpc_xprt *xprt, struct > xdr_skb_reader *desc) > > +static inline void xs_tcp_read_common(struct rpc_xprt *xprt, > > + struct xdr_skb_reader *desc, > > + struct rpc_rqst *req) > > { > > - struct sock_xprt *transport = container_of(xprt, struct sock_xprt, > xprt); > > - struct rpc_rqst *req; > > + struct sock_xprt *transport = > > + container_of(xprt, struct sock_xprt, xprt); > > struct xdr_buf *rcvbuf; > > size_t len; > > ssize_t r; > > > > - /* Find and lock the request corresponding to this xid */ > > - spin_lock(&xprt->transport_lock); > > - req = xprt_lookup_rqst(xprt, transport->tcp_xid); > > - if (!req) { > > - transport->tcp_flags &= ~TCP_RCV_COPY_DATA; > > - dprintk("RPC: XID %08x request not found!\n", > > - ntohl(transport->tcp_xid)); > > - spin_unlock(&xprt->transport_lock); > > - return; > > - } > > - > > rcvbuf = &req->rq_private_buf; > > len = desc->count; > > if (len > transport->tcp_reclen - transport->tcp_offset) { > > @@ -1084,7 +1078,7 @@ static inline void xs_tcp_read_request(struct > rpc_xprt *xprt, struct xdr_skb_rea > > "tcp_offset = %u, tcp_reclen = %u\n", > > xprt, transport->tcp_copied, > > transport->tcp_offset, transport->tcp_reclen); > > - goto out; > > + return; > > } > > > > dprintk("RPC: XID %08x read %Zd bytes\n", > > @@ -1100,11 +1094,122 @@ static inline void xs_tcp_read_request(struct > rpc_xprt *xprt, struct xdr_skb_rea > > transport->tcp_flags &= ~TCP_RCV_COPY_DATA; > > } > > > > -out: > > + return; > > +} > > + > > +/* > > + * Finds the request corresponding to the RPC xid and invokes the > common > > + * tcp read code to read the data. > > + */ > > +static inline int xs_tcp_read_reply(struct rpc_xprt *xprt, > > + struct xdr_skb_reader *desc) > > +{ > > + struct sock_xprt *transport = > > + container_of(xprt, struct sock_xprt, xprt); > > + struct rpc_rqst *req; > > + > > + dprintk("RPC: read reply XID %08x\n", ntohl(transport- > >tcp_xid)); > > + > > + /* Find and lock the request corresponding to this xid */ > > + spin_lock(&xprt->transport_lock); > > + req = xprt_lookup_rqst(xprt, transport->tcp_xid); > > + if (!req) { > > + dprintk("RPC: XID %08x request not found!\n", > > + ntohl(transport->tcp_xid)); > > + spin_unlock(&xprt->transport_lock); > > + return -1; > > + } > > + > > + xs_tcp_read_common(xprt, desc, req); > > + > > if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) > > xprt_complete_rqst(req->rq_task, transport->tcp_copied); > > + > > spin_unlock(&xprt->transport_lock); > > - xs_tcp_check_fraghdr(transport); > > + return 0; > > +} > > + > > +#if defined(CONFIG_NFS_V4_1) > > +/* > > + * Obtains an rpc_rqst previously allocated and invokes the common > > + * tcp read code to read the data. The result is placed in the > callback > > + * queue. > > + * If we're unable to obtain the rpc_rqst we schedule the closing of > the > > + * connection and return -1. > > + */ > > +static inline int xs_tcp_read_callback(struct rpc_xprt *xprt, > > + struct xdr_skb_reader *desc) > > +{ > > + struct sock_xprt *transport = > > + container_of(xprt, struct sock_xprt, xprt); > > + struct rpc_rqst *req; > > + > > + req = xprt_alloc_bc_request(xprt); > > + if (req == NULL) { > > + /* > > + * Schedule an autoclose RPC call > > + */ > > + printk(KERN_WARNING "Callback slot table overflowed\n"); > > + set_bit(XPRT_CLOSE_WAIT, &xprt->state); > > + if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) > > + queue_work(rpciod_workqueue, &xprt->task_cleanup); > > + return -1; > > + } > > + > > + req->rq_xid = transport->tcp_xid; > > + dprintk("RPC: read callback XID %08x\n", ntohl(req->rq_xid)); > > + xs_tcp_read_common(xprt, desc, req); > > + > > + if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) { > > + struct svc_serv *bc_serv = xprt->bc_serv; > > + > > + /* > > + * Add callback request to callback list. The callback > > + * service sleeps on the sv_cb_waitq waiting for new > > + * requests. Wake it up after adding enqueing the > > + * request. > > + */ > > + dprintk("RPC: add callback request to list\n"); > > + spin_lock(&bc_serv->sv_cb_lock); > > + list_add(&req->rq_bc_list, &bc_serv->sv_cb_list); > > + spin_unlock(&bc_serv->sv_cb_lock); > > + wake_up(&bc_serv->sv_cb_waitq); > > + } > > + > > + req->rq_private_buf.len = transport->tcp_copied; > > + > > + return 0; > > +} > > +#endif /* CONFIG_NFS_V4_1 */ > > + > > +/* > > + * Read data off the transport. This can be either an RPC_CALL or an > > + * RPC_REPLY. Relay the processing to helper functions. > > + */ > > +static void xs_tcp_read_data(struct rpc_xprt *xprt, > > + struct xdr_skb_reader *desc) > > +{ > > + struct sock_xprt *transport = > > + container_of(xprt, struct sock_xprt, xprt); > > + int status; > > + > > +#if defined(CONFIG_NFS_V4_1) > > + status = (transport->tcp_flags & TCP_RPC_REPLY) ? > > + xs_tcp_read_reply(xprt, desc) : > > + xs_tcp_read_callback(xprt, desc); > > +#else > > + status = xs_tcp_read_reply(xprt, desc); > > +#endif /* CONFIG_NFS_V4_1 */ > > Ugh... Please don't embed ifdefs in functions like this... > OK, so is it okay to use the CONF_NFS_V4_1 code and remove the ifdefs? - ricardo > > + > > + if (status == 0) > > + xs_tcp_check_fraghdr(transport); > > + else { > > + /* > > + * The transport_lock protects the request handling. > > + * There's no need to hold it to update the tcp_flags. > > + */ > > + transport->tcp_flags &= ~TCP_RCV_COPY_DATA; > > + } > > } > > > > static inline void xs_tcp_read_discard(struct sock_xprt *transport, > struct xdr_skb_reader *desc) > > @@ -1151,7 +1256,7 @@ static int xs_tcp_data_recv(read_descriptor_t > *rd_desc, struct sk_buff *skb, uns > > } > > /* Read in the request data */ > > if (transport->tcp_flags & TCP_RCV_COPY_DATA) { > > - xs_tcp_read_request(xprt, &desc); > > + xs_tcp_read_data(xprt, &desc); > > continue; > > } > > /* Skip over any trailing bytes on short reads */ > > -- > Trond Myklebust > Linux NFS client maintainer > > NetApp > Trond.Myklebust@netapp.com > www.netapp.com > _______________________________________________ > pNFS mailing list > pNFS@linux-nfs.org > http://linux-nfs.org/cgi-bin/mailman/listinfo/pnfs