afs: Wait for outstanding async calls before closing rxrpc socket (2f02f7ae) · Commits · 戴 / test

The afs filesystem needs to wait for any outstanding asynchronous calls (such as FS.GiveUpCallBacks cleaning up the callbacks lodged with a server) to complete before closing the AF_RXRPC socket when unloading the module. This may occur if the module is removed too quickly after unmounting all filesystems. This will produce an error report that looks like: AFS: Assertion failed 1 == 0 is false 0x1 == 0x0 is false ------------[ cut here ]------------ kernel BUG at ../fs/afs/rxrpc.c:135! ... RIP: 0010:[<ffffffffa004111c>] afs_close_socket+0xec/0x107 [kafs] ... Call Trace: [<ffffffffa004a160>] afs_exit+0x1f/0x57 [kafs] [<ffffffff810c30a0>] SyS_delete_module+0xec/0x17d [<ffffffff81610417>] entry_SYSCALL_64_fastpath+0x12/0x6b Signed-off-by:

David Howells <dhowells@redhat.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

fs/afs/rxrpc.c

+13 −3

Original line number	Diff line number	Diff line
		@@ -65,6 +65,12 @@ static void afs_async_workfn(struct work_struct *work)
		call->async_workfn(call);
		}

		static int afs_wait_atomic_t(atomic_t *p)
		{
		schedule();
		return 0;
		}

		/*
		* open an RxRPC socket and bind it to be a server for callback notifications
		* - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
		@@ -126,13 +132,16 @@ void afs_close_socket(void)
		{
		_enter("");

		wait_on_atomic_t(&afs_outstanding_calls, afs_wait_atomic_t,
		TASK_UNINTERRUPTIBLE);
		_debug("no outstanding calls");

		sock_release(afs_socket);

		_debug("dework");
		destroy_workqueue(afs_async_calls);

		ASSERTCMP(atomic_read(&afs_outstanding_skbs), ==, 0);
		ASSERTCMP(atomic_read(&afs_outstanding_calls), ==, 0);
		_leave("");
		}

		@@ -178,8 +187,6 @@ static void afs_free_call(struct afs_call *call)
		{
		_debug("DONE %p{%s} [%d]",
		call, call->type->name, atomic_read(&afs_outstanding_calls));
		if (atomic_dec_return(&afs_outstanding_calls) == -1)
		BUG();

		ASSERTCMP(call->rxcall, ==, NULL);
		ASSERT(!work_pending(&call->async_work));
		@@ -188,6 +195,9 @@ static void afs_free_call(struct afs_call *call)

		kfree(call->request);
		kfree(call);

		if (atomic_dec_and_test(&afs_outstanding_calls))
		wake_up_atomic_t(&afs_outstanding_calls);
		}

		/*

Admin message