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-rw-r--r--net/sunrpc/auth_gss/auth_gss.c64
1 files changed, 61 insertions, 3 deletions
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 51aa27d32b5..e451d104a43 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -75,7 +75,12 @@ struct gss_auth {
struct dentry *dentry;
};
+/* pipe_version >= 0 if and only if someone has a pipe open. */
+static int pipe_version = -1;
static atomic_t pipe_users = ATOMIC_INIT(0);
+static DEFINE_SPINLOCK(pipe_version_lock);
+static struct rpc_wait_queue pipe_version_rpc_waitqueue;
+static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
static void gss_free_ctx(struct gss_cl_ctx *);
static struct rpc_pipe_ops gss_upcall_ops;
@@ -234,12 +239,34 @@ struct gss_upcall_msg {
struct gss_cl_ctx *ctx;
};
+static int get_pipe_version(void)
+{
+ int ret;
+
+ spin_lock(&pipe_version_lock);
+ if (pipe_version >= 0) {
+ atomic_inc(&pipe_users);
+ ret = 0;
+ } else
+ ret = -EAGAIN;
+ spin_unlock(&pipe_version_lock);
+ return ret;
+}
+
+static void put_pipe_version(void)
+{
+ if (atomic_dec_and_lock(&pipe_users, &pipe_version_lock)) {
+ pipe_version = -1;
+ spin_unlock(&pipe_version_lock);
+ }
+}
+
static void
gss_release_msg(struct gss_upcall_msg *gss_msg)
{
if (!atomic_dec_and_test(&gss_msg->count))
return;
- atomic_dec(&pipe_users);
+ put_pipe_version();
BUG_ON(!list_empty(&gss_msg->list));
if (gss_msg->ctx != NULL)
gss_put_ctx(gss_msg->ctx);
@@ -330,11 +357,16 @@ static inline struct gss_upcall_msg *
gss_alloc_msg(struct gss_auth *gss_auth, uid_t uid)
{
struct gss_upcall_msg *gss_msg;
+ int vers;
gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
if (gss_msg == NULL)
return ERR_PTR(-ENOMEM);
- atomic_inc(&pipe_users);
+ vers = get_pipe_version();
+ if (vers < 0) {
+ kfree(gss_msg);
+ return ERR_PTR(vers);
+ }
INIT_LIST_HEAD(&gss_msg->list);
rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
init_waitqueue_head(&gss_msg->waitqueue);
@@ -400,6 +432,14 @@ gss_refresh_upcall(struct rpc_task *task)
dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
cred->cr_uid);
gss_msg = gss_setup_upcall(task->tk_client, gss_auth, cred);
+ if (IS_ERR(gss_msg) == -EAGAIN) {
+ /* XXX: warning on the first, under the assumption we
+ * shouldn't normally hit this case on a refresh. */
+ warn_gssd();
+ task->tk_timeout = 15*HZ;
+ rpc_sleep_on(&pipe_version_rpc_waitqueue, task, NULL);
+ return 0;
+ }
if (IS_ERR(gss_msg)) {
err = PTR_ERR(gss_msg);
goto out;
@@ -437,7 +477,17 @@ gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
int err = 0;
dprintk("RPC: gss_upcall for uid %u\n", cred->cr_uid);
+retry:
gss_msg = gss_setup_upcall(gss_auth->client, gss_auth, cred);
+ if (PTR_ERR(gss_msg) == -EAGAIN) {
+ err = wait_event_interruptible_timeout(pipe_version_waitqueue,
+ pipe_version >= 0, 15*HZ);
+ if (err)
+ goto out;
+ if (pipe_version < 0)
+ warn_gssd();
+ goto retry;
+ }
if (IS_ERR(gss_msg)) {
err = PTR_ERR(gss_msg);
goto out;
@@ -562,7 +612,14 @@ out:
static int
gss_pipe_open(struct inode *inode)
{
+ spin_lock(&pipe_version_lock);
+ if (pipe_version < 0) {
+ pipe_version = 0;
+ rpc_wake_up(&pipe_version_rpc_waitqueue);
+ wake_up(&pipe_version_waitqueue);
+ }
atomic_inc(&pipe_users);
+ spin_unlock(&pipe_version_lock);
return 0;
}
@@ -586,7 +643,7 @@ gss_pipe_release(struct inode *inode)
}
spin_unlock(&inode->i_lock);
- atomic_dec(&pipe_users);
+ put_pipe_version();
}
static void
@@ -1379,6 +1436,7 @@ static int __init init_rpcsec_gss(void)
err = gss_svc_init();
if (err)
goto out_unregister;
+ rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
return 0;
out_unregister:
rpcauth_unregister(&authgss_ops);