SUNRPC: Fix a lock recursion in the auth_gss downcall
When we look up a new cred in the auth_gss downcall so that we can stuff
the credcache, we do not want that lookup to queue up an upcall in order
to initialise it. To do an upcall here not only redundant, but since we
are already holding the inode->i_mutex, it will trigger a lock recursion.
This patch allows rpcauth cache searches to indicate that they can cope
with uninitialised credentials.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index 9ac1b8c..1ca89c3 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -184,7 +184,7 @@
*/
struct rpc_cred *
rpcauth_lookup_credcache(struct rpc_auth *auth, struct auth_cred * acred,
- int taskflags)
+ int flags)
{
struct rpc_cred_cache *cache = auth->au_credcache;
HLIST_HEAD(free);
@@ -193,7 +193,7 @@
*cred = NULL;
int nr = 0;
- if (!(taskflags & RPC_TASK_ROOTCREDS))
+ if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS))
nr = acred->uid & RPC_CREDCACHE_MASK;
retry:
spin_lock(&rpc_credcache_lock);
@@ -202,7 +202,7 @@
hlist_for_each_safe(pos, next, &cache->hashtable[nr]) {
struct rpc_cred *entry;
entry = hlist_entry(pos, struct rpc_cred, cr_hash);
- if (entry->cr_ops->crmatch(acred, entry, taskflags)) {
+ if (entry->cr_ops->crmatch(acred, entry, flags)) {
hlist_del(&entry->cr_hash);
cred = entry;
break;
@@ -224,7 +224,7 @@
rpcauth_destroy_credlist(&free);
if (!cred) {
- new = auth->au_ops->crcreate(auth, acred, taskflags);
+ new = auth->au_ops->crcreate(auth, acred, flags);
if (!IS_ERR(new)) {
#ifdef RPC_DEBUG
new->cr_magic = RPCAUTH_CRED_MAGIC;
@@ -238,7 +238,7 @@
}
struct rpc_cred *
-rpcauth_lookupcred(struct rpc_auth *auth, int taskflags)
+rpcauth_lookupcred(struct rpc_auth *auth, int flags)
{
struct auth_cred acred = {
.uid = current->fsuid,
@@ -250,7 +250,7 @@
dprintk("RPC: looking up %s cred\n",
auth->au_ops->au_name);
get_group_info(acred.group_info);
- ret = auth->au_ops->lookup_cred(auth, &acred, taskflags);
+ ret = auth->au_ops->lookup_cred(auth, &acred, flags);
put_group_info(acred.group_info);
return ret;
}
@@ -265,11 +265,14 @@
.group_info = current->group_info,
};
struct rpc_cred *ret;
+ int flags = 0;
dprintk("RPC: %4d looking up %s cred\n",
task->tk_pid, task->tk_auth->au_ops->au_name);
get_group_info(acred.group_info);
- ret = auth->au_ops->lookup_cred(auth, &acred, task->tk_flags);
+ if (task->tk_flags & RPC_TASK_ROOTCREDS)
+ flags |= RPCAUTH_LOOKUP_ROOTCREDS;
+ ret = auth->au_ops->lookup_cred(auth, &acred, flags);
if (!IS_ERR(ret))
task->tk_msg.rpc_cred = ret;
else