[PATCH 3.16 150/346] SUNRPC: allow for upcalls for same uid but different gss service

[Ben Hutchings]

3.16.39-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Olga Kornievskaia <kolga@xxxxxxxxxx>

commit 9130b8dbc6ac20f2dc5846e1647f5b60eafab6e3 upstream.

It's possible to have simultaneous upcalls for the same UIDs but
different GSS service. In that case, we need to allow for the
upcall to gssd to proceed so that not the same context is used
by two different GSS services. Some servers lock the use of context
to the GSS service.

Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx>
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 net/sunrpc/auth_gss/auth_gss.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -326,12 +326,14 @@ gss_release_msg(struct gss_upcall_msg *g
 }
 
 static struct gss_upcall_msg *
-__gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid)
+__gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid, const struct gss_auth *auth)
 {
 	struct gss_upcall_msg *pos;
 	list_for_each_entry(pos, &pipe->in_downcall, list) {
 		if (!uid_eq(pos->uid, uid))
 			continue;
+		if (auth && pos->auth->service != auth->service)
+			continue;
 		atomic_inc(&pos->count);
 		dprintk("RPC:       %s found msg %p\n", __func__, pos);
 		return pos;
@@ -351,7 +353,7 @@ gss_add_msg(struct gss_upcall_msg *gss_m
 	struct gss_upcall_msg *old;
 
 	spin_lock(&pipe->lock);
-	old = __gss_find_upcall(pipe, gss_msg->uid);
+	old = __gss_find_upcall(pipe, gss_msg->uid, gss_msg->auth);
 	if (old == NULL) {
 		atomic_inc(&gss_msg->count);
 		list_add(&gss_msg->list, &pipe->in_downcall);
@@ -700,7 +702,7 @@ gss_pipe_downcall(struct file *filp, con
 	err = -ENOENT;
 	/* Find a matching upcall */
 	spin_lock(&pipe->lock);
-	gss_msg = __gss_find_upcall(pipe, uid);
+	gss_msg = __gss_find_upcall(pipe, uid, NULL);
 	if (gss_msg == NULL) {
 		spin_unlock(&pipe->lock);
 		goto err_put_ctx;