From ca979525615ccd8c9115b0ac831a77db7e7c53ff Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 18 Sep 2012 16:20:35 -0700 Subject: [PATCH] cifs: cork the socket before a send and uncork it afterward We want to send SMBs as "atomically" as possible. Prior to sending any data on the socket, cork it to make sure that no non-full frames go out. Afterward, uncork it to make sure all of the data gets pushed out to the wire. Note that this more or less renders the socket=TCP_NODELAY mount option obsolete. When TCP_CORK and TCP_NODELAY are used on the same socket, TCP_NODELAY is essentially ignored. Acked-by: Pavel Shilovsky Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/connect.c | 4 ++++ fs/cifs/transport.c | 12 ++++++++++++ 2 files changed, 16 insertions(+) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 549409b1c776..5210bc82b1dc 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1680,6 +1680,10 @@ cifs_parse_mount_options(const char *mountdata, const char *devname, if (string == NULL) goto out_nomem; + /* + * FIXME: since we now cork/uncork the socket while + * sending, should we deprecate this option? + */ if (strnicmp(string, "TCP_NODELAY", 11) == 0) vol->sockopt_tcp_nodelay = 1; break; diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index 766307b725bd..8ff4c5f36702 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include #include @@ -247,12 +248,23 @@ smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst) int n_vec = rqst->rq_nvec; unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base); size_t total_len; + struct socket *ssocket = server->ssocket; + int val = 1; cFYI(1, "Sending smb: smb_len=%u", smb_buf_length); dump_smb(iov[0].iov_base, iov[0].iov_len); + /* cork the socket */ + kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK, + (char *)&val, sizeof(val)); + rc = smb_send_kvec(server, iov, n_vec, &total_len); + /* uncork it */ + val = 0; + kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK, + (char *)&val, sizeof(val)); + if ((total_len > 0) && (total_len != smb_buf_length + 4)) { cFYI(1, "partial send (wanted=%u sent=%zu): terminating " "session", smb_buf_length + 4, total_len); -- 2.39.5