| From | Paul Gortmaker <> | Subject | [v2.6.34-stable 195/213] svcrpc: sends on closed socket should stop immediately | Date | Wed, 5 Feb 2014 15:02:30 -0500 |
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From: "J. Bruce Fields" <bfields@redhat.com>
------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. -------------------
commit f06f00a24d76e168ecb38d352126fd203937b601 upstream.
svc_tcp_sendto sets XPT_CLOSE if we fail to transmit the entire reply. However, the XPT_CLOSE won't be acted on immediately. Meanwhile other threads could send further replies before the socket is really shut down. This can manifest as data corruption: for example, if a truncated read reply is followed by another rpc reply, that second reply will look to the client like further read data.
Symptoms were data corruption preceded by svc_tcp_sendto logging something like
kernel: rpc-srv/tcp: nfsd: sent only 963696 when sending 1048708 bytes - shutting down socket
Reported-by: Malahal Naineni <malahal@us.ibm.com> Tested-by: Malahal Naineni <malahal@us.ibm.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> --- net/sunrpc/svc_xprt.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index 33df29bd8c61..957a7e88e827 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -807,7 +807,8 @@ int svc_send(struct svc_rqst *rqstp) /* Grab mutex to serialize outgoing data. */ mutex_lock(&xprt->xpt_mutex); - if (test_bit(XPT_DEAD, &xprt->xpt_flags)) + if (test_bit(XPT_DEAD, &xprt->xpt_flags) + || test_bit(XPT_CLOSE, &xprt->xpt_flags)) len = -ENOTCONN; else len = xprt->xpt_ops->xpo_sendto(rqstp); -- 1.8.5.2
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