From 43d78ef2ba5bec26d0315859e8324bfc0be23766 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Tue, 6 Feb 2007 18:26:11 -0500 Subject: [PATCH] NFS: disconnect before retrying NFSv4 requests over TCP RFC3530 section 3.1.1 states an NFSv4 client MUST NOT send a request twice on the same connection unless it is the NULL procedure. Section 3.1.1 suggests that the client should disconnect and reconnect if it wants to retry a request. Implement this by adding an rpc_clnt flag that an ULP can use to specify that the underlying transport should be disconnected on a major timeout. The NFSv4 client asserts this new flag, and requests no retries after a minor retransmit timeout. Note that disconnecting on a retransmit is in general not safe to do if the RPC client does not reuse the TCP port number when reconnecting. See http://bugzilla.linux-nfs.org/show_bug.cgi?id=6 Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- fs/nfs/client.c | 9 ++++++--- include/linux/sunrpc/clnt.h | 2 ++ net/sunrpc/clnt.c | 2 ++ net/sunrpc/xprt.c | 10 ++++++++++ 4 files changed, 20 insertions(+), 3 deletions(-) diff --git a/fs/nfs/client.c b/fs/nfs/client.c index a3191f023490..c46e94fed9eb 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -394,7 +394,8 @@ static void nfs_init_timeout_values(struct rpc_timeout *to, int proto, static int nfs_create_rpc_client(struct nfs_client *clp, int proto, unsigned int timeo, unsigned int retrans, - rpc_authflavor_t flavor) + rpc_authflavor_t flavor, + int flags) { struct rpc_timeout timeparms; struct rpc_clnt *clnt = NULL; @@ -407,6 +408,7 @@ static int nfs_create_rpc_client(struct nfs_client *clp, int proto, .program = &nfs_program, .version = clp->rpc_ops->version, .authflavor = flavor, + .flags = flags, }; if (!IS_ERR(clp->cl_rpcclient)) @@ -548,7 +550,7 @@ static int nfs_init_client(struct nfs_client *clp, const struct nfs_mount_data * * - RFC 2623, sec 2.3.2 */ error = nfs_create_rpc_client(clp, proto, data->timeo, data->retrans, - RPC_AUTH_UNIX); + RPC_AUTH_UNIX, 0); if (error < 0) goto error; nfs_mark_client_ready(clp, NFS_CS_READY); @@ -868,7 +870,8 @@ static int nfs4_init_client(struct nfs_client *clp, /* Check NFS protocol revision and initialize RPC op vector */ clp->rpc_ops = &nfs_v4_clientops; - error = nfs_create_rpc_client(clp, proto, timeo, retrans, authflavour); + error = nfs_create_rpc_client(clp, proto, timeo, retrans, authflavour, + RPC_CLNT_CREATE_DISCRTRY); if (error < 0) goto error; memcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr)); diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h index a1be89deb3af..c7a78eef2b4f 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -40,6 +40,7 @@ struct rpc_clnt { unsigned int cl_softrtry : 1,/* soft timeouts */ cl_intr : 1,/* interruptible */ + cl_discrtry : 1,/* disconnect before retry */ cl_autobind : 1,/* use getport() */ cl_oneshot : 1,/* dispose after use */ cl_dead : 1;/* abandoned */ @@ -111,6 +112,7 @@ struct rpc_create_args { #define RPC_CLNT_CREATE_ONESHOT (1UL << 3) #define RPC_CLNT_CREATE_NONPRIVPORT (1UL << 4) #define RPC_CLNT_CREATE_NOPING (1UL << 5) +#define RPC_CLNT_CREATE_DISCRTRY (1UL << 6) struct rpc_clnt *rpc_create(struct rpc_create_args *args); struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *, diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 393e70aee181..c21aa0a7f770 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -249,6 +249,8 @@ struct rpc_clnt *rpc_create(struct rpc_create_args *args) clnt->cl_autobind = 1; if (args->flags & RPC_CLNT_CREATE_ONESHOT) clnt->cl_oneshot = 1; + if (args->flags & RPC_CLNT_CREATE_DISCRTRY) + clnt->cl_discrtry = 1; return clnt; } diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index cf59f7d315d0..1975139b26e7 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -735,6 +735,16 @@ void xprt_transmit(struct rpc_task *task) xprt_reset_majortimeo(req); /* Turn off autodisconnect */ del_singleshot_timer_sync(&xprt->timer); + } else { + /* If all request bytes have been sent, + * then we must be retransmitting this one */ + if (!req->rq_bytes_sent) { + if (task->tk_client->cl_discrtry) { + xprt_disconnect(xprt); + task->tk_status = -ENOTCONN; + return; + } + } } } else if (!req->rq_bytes_sent) return; -- 2.20.1