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>
This commit is contained in:
J. Bruce Fields 2007-11-06 13:05:36 -05:00 committed by Trond Myklebust
parent ef338bee3f
commit eda4f9b799

View file

@ -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;
}