Fix a second potential rpc_wakeup race...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 8118036..93ac058 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -636,7 +636,7 @@ static int _nfs4_proc_open_confirm(struct nfs4_opendata *data)
                smp_wmb();
        } else
                status = data->rpc_status;
-       rpc_release_task(task);
+       rpc_put_task(task);
        return status;
 }
 
@@ -742,7 +742,7 @@ static int _nfs4_proc_open(struct nfs4_opendata *data)
                smp_wmb();
        } else
                status = data->rpc_status;
-       rpc_release_task(task);
+       rpc_put_task(task);
        if (status != 0)
                return status;
 
@@ -3067,7 +3067,7 @@ static int _nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, co
                if (status == 0)
                        nfs_post_op_update_inode(inode, &data->fattr);
        }
-       rpc_release_task(task);
+       rpc_put_task(task);
        return status;
 }
 
@@ -3314,7 +3314,7 @@ static int nfs4_proc_unlck(struct nfs4_state *state, int cmd, struct file_lock *
        if (IS_ERR(task))
                goto out;
        status = nfs4_wait_for_completion_rpc_task(task);
-       rpc_release_task(task);
+       rpc_put_task(task);
 out:
        return status;
 }
@@ -3430,7 +3430,7 @@ static void nfs4_lock_release(void *calldata)
                task = nfs4_do_unlck(&data->fl, data->ctx, data->lsp,
                                data->arg.lock_seqid);
                if (!IS_ERR(task))
-                       rpc_release_task(task);
+                       rpc_put_task(task);
                dprintk("%s: cancelling lock!\n", __FUNCTION__);
        } else
                nfs_free_seqid(data->arg.lock_seqid);
@@ -3472,7 +3472,7 @@ static int _nfs4_do_setlk(struct nfs4_state *state, int cmd, struct file_lock *f
                        ret = -EAGAIN;
        } else
                data->cancelled = 1;
-       rpc_release_task(task);
+       rpc_put_task(task);
        dprintk("%s: done, ret = %d!\n", __FUNCTION__, ret);
        return ret;
 }

diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index f399c13..9fdb8c9 100644 (file)
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -178,13 +178,6 @@ struct rpc_call_ops {
        } while (0)
 
 #define RPC_IS_ACTIVATED(t)    (test_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate))
-#define rpc_set_active(t)      (set_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate))
-#define rpc_clear_active(t)    \
-       do { \
-               smp_mb__before_clear_bit(); \
-               clear_bit(RPC_TASK_ACTIVE, &(t)->tk_runstate); \
-               smp_mb__after_clear_bit(); \
-       } while(0)
 
 /*
  * Task priorities.
@@ -254,6 +247,7 @@ struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags,
 void           rpc_init_task(struct rpc_task *task, struct rpc_clnt *clnt,
                                int flags, const struct rpc_call_ops *ops,
                                void *data);
+void           rpc_put_task(struct rpc_task *);
 void           rpc_release_task(struct rpc_task *);
 void           rpc_exit_task(struct rpc_task *);
 void           rpc_killall_tasks(struct rpc_clnt *);

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index dfeea4f..a323abc 100644 (file)
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -466,10 +466,9 @@ int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 
        BUG_ON(flags & RPC_TASK_ASYNC);
 
-       status = -ENOMEM;
        task = rpc_new_task(clnt, flags, &rpc_default_ops, NULL);
        if (task == NULL)
-               goto out;
+               return -ENOMEM;
 
        /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */
        rpc_task_sigmask(task, &oldset);
@@ -478,15 +477,17 @@ int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 
        /* Set up the call info struct and execute the task */
        status = task->tk_status;
-       if (status == 0) {
-               atomic_inc(&task->tk_count);
-               status = rpc_execute(task);
-               if (status == 0)
-                       status = task->tk_status;
+       if (status != 0) {
+               rpc_release_task(task);
+               goto out;
        }
-       rpc_restore_sigmask(&oldset);
-       rpc_release_task(task);
+       atomic_inc(&task->tk_count);
+       status = rpc_execute(task);
+       if (status == 0)
+               status = task->tk_status;
+       rpc_put_task(task);
 out:
+       rpc_restore_sigmask(&oldset);
        return status;
 }
 

diff --git a/net/sunrpc/pmap_clnt.c b/net/sunrpc/pmap_clnt.c
index e52afab..8d2e10f 100644 (file)
--- a/net/sunrpc/pmap_clnt.c
+++ b/net/sunrpc/pmap_clnt.c
@@ -134,7 +134,7 @@ void rpc_getport(struct rpc_task *task)
        child = rpc_run_task(pmap_clnt, RPC_TASK_ASYNC, &pmap_getport_ops, map);
        if (IS_ERR(child))
                goto bailout;
-       rpc_release_task(child);
+       rpc_put_task(child);
 
        task->tk_xprt->stat.bind_count++;
        return;

diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index b57d406..66d0136 100644 (file)
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -266,12 +266,28 @@ static int rpc_wait_bit_interruptible(void *word)
        return 0;
 }
 
+static void rpc_set_active(struct rpc_task *task)
+{
+       if (test_and_set_bit(RPC_TASK_ACTIVE, &task->tk_runstate) != 0)
+               return;
+       spin_lock(&rpc_sched_lock);
+#ifdef RPC_DEBUG
+       task->tk_magic = RPC_TASK_MAGIC_ID;
+       task->tk_pid = rpc_task_id++;
+#endif
+       /* Add to global list of all tasks */
+       list_add_tail(&task->tk_task, &all_tasks);
+       spin_unlock(&rpc_sched_lock);
+}
+
 /*
  * Mark an RPC call as having completed by clearing the 'active' bit
  */
-static inline void rpc_mark_complete_task(struct rpc_task *task)
+static void rpc_mark_complete_task(struct rpc_task *task)
 {
-       rpc_clear_active(task);
+       smp_mb__before_clear_bit();
+       clear_bit(RPC_TASK_ACTIVE, &task->tk_runstate);
+       smp_mb__after_clear_bit();
        wake_up_bit(&task->tk_runstate, RPC_TASK_ACTIVE);
 }
 
@@ -335,9 +351,6 @@ static void __rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
                return;
        }
 
-       /* Mark the task as being activated if so needed */
-       rpc_set_active(task);
-
        __rpc_add_wait_queue(q, task);
 
        BUG_ON(task->tk_callback != NULL);
@@ -348,6 +361,9 @@ static void __rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
 void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
                                rpc_action action, rpc_action timer)
 {
+       /* Mark the task as being activated if so needed */
+       rpc_set_active(task);
+
        /*
         * Protect the queue operations.
         */
@@ -673,8 +689,6 @@ static int __rpc_execute(struct rpc_task *task)
        }
 
        dprintk("RPC: %4d, return %d, status %d\n", task->tk_pid, status, task->tk_status);
-       /* Wake up anyone who is waiting for task completion */
-       rpc_mark_complete_task(task);
        /* Release all resources associated with the task */
        rpc_release_task(task);
        return status;
@@ -788,15 +802,6 @@ void rpc_init_task(struct rpc_task *task, struct rpc_clnt *clnt, int flags, cons
                        task->tk_flags |= RPC_TASK_NOINTR;
        }
 
-#ifdef RPC_DEBUG
-       task->tk_magic = RPC_TASK_MAGIC_ID;
-       task->tk_pid = rpc_task_id++;
-#endif
-       /* Add to global list of all tasks */
-       spin_lock(&rpc_sched_lock);
-       list_add_tail(&task->tk_task, &all_tasks);
-       spin_unlock(&rpc_sched_lock);
-
        BUG_ON(task->tk_ops == NULL);
 
        /* starting timestamp */
@@ -849,16 +854,35 @@ cleanup:
        goto out;
 }
 
-void rpc_release_task(struct rpc_task *task)
+
+void rpc_put_task(struct rpc_task *task)
 {
        const struct rpc_call_ops *tk_ops = task->tk_ops;
        void *calldata = task->tk_calldata;
 
+       if (!atomic_dec_and_test(&task->tk_count))
+               return;
+       /* Release resources */
+       if (task->tk_rqstp)
+               xprt_release(task);
+       if (task->tk_msg.rpc_cred)
+               rpcauth_unbindcred(task);
+       if (task->tk_client) {
+               rpc_release_client(task->tk_client);
+               task->tk_client = NULL;
+       }
+       if (task->tk_flags & RPC_TASK_DYNAMIC)
+               rpc_free_task(task);
+       if (tk_ops->rpc_release)
+               tk_ops->rpc_release(calldata);
+}
+EXPORT_SYMBOL(rpc_put_task);
+
+void rpc_release_task(struct rpc_task *task)
+{
 #ifdef RPC_DEBUG
        BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID);
 #endif
-       if (!atomic_dec_and_test(&task->tk_count))
-               return;
        dprintk("RPC: %4d release task\n", task->tk_pid);
 
        /* Remove from global task list */
@@ -871,23 +895,13 @@ void rpc_release_task(struct rpc_task *task)
        /* Synchronously delete any running timer */
        rpc_delete_timer(task);
 
-       /* Release resources */
-       if (task->tk_rqstp)
-               xprt_release(task);
-       if (task->tk_msg.rpc_cred)
-               rpcauth_unbindcred(task);
-       if (task->tk_client) {
-               rpc_release_client(task->tk_client);
-               task->tk_client = NULL;
-       }
-
 #ifdef RPC_DEBUG
        task->tk_magic = 0;
 #endif
-       if (task->tk_flags & RPC_TASK_DYNAMIC)
-               rpc_free_task(task);
-       if (tk_ops->rpc_release)
-               tk_ops->rpc_release(calldata);
+       /* Wake up anyone who is waiting for task completion */
+       rpc_mark_complete_task(task);
+
+       rpc_put_task(task);
 }
 
 /**

diff --git a/net/sunrpc/sunrpc_syms.c b/net/sunrpc/sunrpc_syms.c
index 192dff5..faaf81e 100644 (file)
--- a/net/sunrpc/sunrpc_syms.c
+++ b/net/sunrpc/sunrpc_syms.c
@@ -33,7 +33,6 @@ EXPORT_SYMBOL(rpciod_down);
 EXPORT_SYMBOL(rpciod_up);
 EXPORT_SYMBOL(rpc_new_task);
 EXPORT_SYMBOL(rpc_wake_up_status);
-EXPORT_SYMBOL(rpc_release_task);
 
 /* RPC client functions */
 EXPORT_SYMBOL(rpc_clone_client);