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author\"J. Bruce Fields\ <bfields@citi.umich.edu>2008-12-23 16:10:52 -0500
committerTrond Myklebust <Trond.Myklebust@netapp.com>2008-12-23 16:10:52 -0500
commit79a3f20b641f9f93787ada49d1d7cfa98ee5a11e (patch)
tree2f7d9f49b18388eb61400e383a9c5c4b070f1915 /net
parentcf81939d6fcdf381fcb069d780c29eceb516bccd (diff)
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rpc: use count of pipe openers to wait for first open
Introduce a global variable pipe_version which will eventually be used to keep track of which version of the upcall gssd is using. For now, though, it only keeps track of whether any pipe is open or not; it is negative if not, zero if one is opened. We use this to wait for the first gssd to open a pipe. (Minor digression: note this waits only for the very first open of any pipe, not for the first open of a pipe for a given auth; thus we still need the RPC_PIPE_WAIT_FOR_OPEN behavior to wait for gssd to open new pipes that pop up on subsequent mounts.) Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'net')
-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);