From mboxrd@z Thu Jan  1 00:00:00 1970
From: Richard J.Farnsworth <rjf@maui.cs.washington.edu>
Subject: Bug in NFS client handling of EJUKEBOX?
Date: Thu, 24 Feb 2005 06:05:38 +0000 (UTC)
Message-ID: <1109028596/rjf@maui.cs.washington.edu>
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Date: Wed Feb 23 22:06:48 2005

There seems to be a bug in the 2.6.11-rc code related to the handling
of nfsd's EJUNKBOX error return.  The code for __rpc_execute in
net/sunrpc/sched.c looks like:

=============================

static int __rpc_execute(struct rpc_task *task)
{
	int		status = 0;

	dprintk("RPC: %4d rpc_execute flgs %x\n",
				task->tk_pid, task->tk_flags);

	BUG_ON(RPC_IS_QUEUED(task));

 restarted:
	while (1) {
		/*
		 * Garbage collection of pending timers...
		 */
		rpc_delete_timer(task);

 .....

	if (task->tk_exit) {
		lock_kernel();
>>>>		task->tk_exit(task);
		unlock_kernel();
		/* If tk_action is non-null, the user wants us to restart */
		if (task->tk_action) {
			if (!RPC_ASSASSINATED(task)) {
				/* Release RPC slot and buffer memory */
				if (task->tk_rqstp)
					xprt_release(task);
				rpc_free(task);
				goto restarted;
			}
			printk(KERN_ERR "RPC: dead task tries to walk away.\n");
		}
	}

=============================

If the tk_exit procedure (e.g., nfs_read_done) called at ">>>>" above
detects EJUKEBOX as the result of the call, it will attempt to do
an rpc_restart and rpc_delay on the task.  The rpc_delay will set a timer.
However, when the main loop is re-entered via the "goto restarted",
the first thing that happens is that all timers for the task are removed.
This results in the RPC task hanging in an uninterruptible wait.

Am I missing something here or is this really a problem?





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