From: J. Bruce Fields <bfields@citi.umich.edu>
Date: Tue, 6 Nov 2007 18:05:36 +0000 (-0500)
Subject: sunrpc: rpc_pipe_poll may miss available data in some cases
X-Git-Tag: v2.6.24-rc4~92^2~11
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=eda4f9b7996e5520934ca2a7310b363463a4e3b0;p=linux-2.6

sunrpc: rpc_pipe_poll may miss available data in some cases

Pipe messages start out life on a queue on the inode, but when first
read they're moved to the filp's private pointer.  So it's possible for
a poll here to return null even though there's a partially read message
available.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
---

diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 18f0a8dcc0..c59f3ca2b4 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -280,7 +280,7 @@ rpc_pipe_poll(struct file *filp, struct poll_table_struct *wait)
 	mask = POLLOUT | POLLWRNORM;
 	if (rpci->ops == NULL)
 		mask |= POLLERR | POLLHUP;
-	if (!list_empty(&rpci->pipe))
+	if (filp->private_data || !list_empty(&rpci->pipe))
 		mask |= POLLIN | POLLRDNORM;
 	return mask;
 }