SUNRPC: Fix use of copy_to_user() in gss_pipe_upcall()

The gss_pipe_upcall() function expects the copy_to_user() function to
return a negative error value if the call fails, but copy_to_user()
returns an unsigned long number of bytes that couldn't be copied.

Can rpc_pipefs actually retry a partially completed upcall read?  If
not, then gss_pipe_upcall() should punt any partial read, just like the
upcall logic in net/sunrpc/cache.c.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever 2007-12-20 14:54:27 -05:00 committed by Trond Myklebust
parent 59dca3b28c
commit 7df089952f

View file

@ -472,16 +472,15 @@ gss_pipe_upcall(struct file *filp, struct rpc_pipe_msg *msg,
char __user *dst, size_t buflen)
{
char *data = (char *)msg->data + msg->copied;
ssize_t mlen = msg->len;
ssize_t left;
size_t mlen = min(msg->len, buflen);
unsigned long left;
if (mlen > buflen)
mlen = buflen;
left = copy_to_user(dst, data, mlen);
if (left < 0) {
msg->errno = left;
return left;
if (left == mlen) {
msg->errno = -EFAULT;
return -EFAULT;
}
mlen -= left;
msg->copied += mlen;
msg->errno = 0;