[PATCH 1/2] sunrpc: rpc_pipe_poll may miss available data in some cases

[J. Bruce Fields]

From: J. Bruce Fields <bfields at citi.umich.edu>

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 at citi.umich.edu>
---
 net/sunrpc/rpc_pipe.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 18f0a8d..c59f3ca 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;
 }
-- 
1.5.3.5.561.g140d