diff options
| -rw-r--r-- | net/sunrpc/auth_gss/auth_gss.c | 64 |
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 51aa27d32b5a..e451d104a434 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); |