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Commit f609266b authored by Trond Myklebust's avatar Trond Myklebust Committed by Greg Kroah-Hartman
Browse files

NFSv4: Fix callback server shutdown 



commit ed6473ddc704a2005b9900ca08e236ebb2d8540a upstream.

We want to use kthread_stop() in order to ensure the threads are
shut down before we tear down the nfs_callback_info in nfs_callback_down.

Tested-and-reviewed-by: default avatarKinglong Mee <kinglongmee@gmail.com>
Reported-by: default avatarKinglong Mee <kinglongmee@gmail.com>
Fixes: bb6aeba7 ("NFSv4.x: Switch to using svc_set_num_threads()...")
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
Cc: Jan Hudoba <kernel@jahu.sk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d9f9b835

fs/nfs/callback.c

+16 −8
Original line number Diff line number Diff line
@@ -75,7 +75,10 @@ nfs4_callback_svc(void *vrqstp) 


	set_freezable();



	while (!kthread_should_stop()) {

	while (!kthread_freezable_should_stop(NULL)) {



		if (signal_pending(current))

			flush_signals(current);

		/*

		 * Listen for a request on the socket

		 */
@@ -84,6 +87,8 @@ nfs4_callback_svc(void *vrqstp) 
			continue;

		svc_process(rqstp);

	}

	svc_exit_thread(rqstp);

	module_put_and_exit(0);

	return 0;

}
@@ -102,9 +107,10 @@ nfs41_callback_svc(void *vrqstp) 


	set_freezable();



	while (!kthread_should_stop()) {

		if (try_to_freeze())

			continue;

	while (!kthread_freezable_should_stop(NULL)) {



		if (signal_pending(current))

			flush_signals(current);



		prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);

		spin_lock_bh(&serv->sv_cb_lock);
@@ -120,11 +126,13 @@ nfs41_callback_svc(void *vrqstp) 
				error);

		} else {

			spin_unlock_bh(&serv->sv_cb_lock);

			if (!kthread_should_stop())

				schedule();

			finish_wait(&serv->sv_cb_waitq, &wq);

		}

		flush_signals(current);

	}

	svc_exit_thread(rqstp);

	module_put_and_exit(0);

	return 0;

}
@@ -220,14 +228,14 @@ static int nfs_callback_up_net(int minorversion, struct svc_serv *serv, 
static struct svc_serv_ops nfs40_cb_sv_ops = {

	.svo_function		= nfs4_callback_svc,

	.svo_enqueue_xprt	= svc_xprt_do_enqueue,

	.svo_setup		= svc_set_num_threads,

	.svo_setup		= svc_set_num_threads_sync,

	.svo_module		= THIS_MODULE,

};

#if defined(CONFIG_NFS_V4_1)

static struct svc_serv_ops nfs41_cb_sv_ops = {

	.svo_function		= nfs41_callback_svc,

	.svo_enqueue_xprt	= svc_xprt_do_enqueue,

	.svo_setup		= svc_set_num_threads,

	.svo_setup		= svc_set_num_threads_sync,

	.svo_module		= THIS_MODULE,

};

include/linux/sunrpc/svc.h

+1 −0
Original line number Diff line number Diff line
@@ -470,6 +470,7 @@ void svc_pool_map_put(void); 
struct svc_serv *  svc_create_pooled(struct svc_program *, unsigned int,

			struct svc_serv_ops *);

int		   svc_set_num_threads(struct svc_serv *, struct svc_pool *, int);

int		   svc_set_num_threads_sync(struct svc_serv *, struct svc_pool *, int);

int		   svc_pool_stats_open(struct svc_serv *serv, struct file *file);

void		   svc_destroy(struct svc_serv *);

void		   svc_shutdown_net(struct svc_serv *, struct net *);

net/sunrpc/svc.c

+38 −0
Original line number Diff line number Diff line
@@ -795,6 +795,44 @@ svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs) 
}

EXPORT_SYMBOL_GPL(svc_set_num_threads);



/* destroy old threads */

static int

svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)

{

	struct task_struct *task;

	unsigned int state = serv->sv_nrthreads-1;



	/* destroy old threads */

	do {

		task = choose_victim(serv, pool, &state);

		if (task == NULL)

			break;

		kthread_stop(task);

		nrservs++;

	} while (nrservs < 0);

	return 0;

}



int

svc_set_num_threads_sync(struct svc_serv *serv, struct svc_pool *pool, int nrservs)

{

	if (pool == NULL) {

		/* The -1 assumes caller has done a svc_get() */

		nrservs -= (serv->sv_nrthreads-1);

	} else {

		spin_lock_bh(&pool->sp_lock);

		nrservs -= pool->sp_nrthreads;

		spin_unlock_bh(&pool->sp_lock);

	}



	if (nrservs > 0)

		return svc_start_kthreads(serv, pool, nrservs);

	if (nrservs < 0)

		return svc_stop_kthreads(serv, pool, nrservs);

	return 0;

}

EXPORT_SYMBOL_GPL(svc_set_num_threads_sync);



/*

 * Called from a server thread as it's exiting. Caller must hold the "service

 * mutex" for the service.