Commit 59fa1c4a authored by David Howells's avatar David Howells
Browse files

afs: Fix server reaping 



Fix server reaping and make sure it's all done before we start trying to
purge cells, given that servers currently pin cells.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
parent e3b2ffe0

fs/afs/internal.h

+4 −1
Original line number Diff line number Diff line
@@ -238,7 +238,9 @@ struct afs_net { 
	rwlock_t		servers_lock;

	struct list_head	server_graveyard;	/* Inactive server LRU list */

	spinlock_t		server_graveyard_lock;

	struct delayed_work	server_reaper;

	struct timer_list	server_timer;

	struct work_struct	server_reaper;

	atomic_t		servers_outstanding;



	/* Misc */

	struct proc_dir_entry	*proc_afs;		/* /proc/net/afs directory */
@@ -700,6 +702,7 @@ do { \ 
	atomic_inc(&(S)->usage);				\

} while(0)



extern void afs_server_timer(struct timer_list *);

extern struct afs_server *afs_lookup_server(struct afs_cell *,

					    const struct in_addr *);

extern struct afs_server *afs_find_server(struct afs_net *,

fs/afs/main.c

+2 −1
Original line number Diff line number Diff line
@@ -62,7 +62,8 @@ static int __net_init afs_net_init(struct afs_net *net) 
	rwlock_init(&net->servers_lock);

	INIT_LIST_HEAD(&net->server_graveyard);

	spin_lock_init(&net->server_graveyard_lock);

	INIT_DELAYED_WORK(&net->server_reaper, afs_reap_server);

	INIT_WORK(&net->server_reaper, afs_reap_server);

	timer_setup(&net->server_timer, afs_server_timer, 0);



	/* Register the /proc stuff */

	ret = afs_proc_init(net);

fs/afs/server.c

+51 −8
Original line number Diff line number Diff line
@@ -15,6 +15,25 @@ 


static unsigned afs_server_timeout = 10;	/* server timeout in seconds */



static void afs_inc_servers_outstanding(struct afs_net *net)

{

	atomic_inc(&net->servers_outstanding);

}



static void afs_dec_servers_outstanding(struct afs_net *net)

{

	if (atomic_dec_and_test(&net->servers_outstanding))

		wake_up_atomic_t(&net->servers_outstanding);

}



void afs_server_timer(struct timer_list *timer)

{

	struct afs_net *net = container_of(timer, struct afs_net, server_timer);



	if (!queue_work(afs_wq, &net->server_reaper))

		afs_dec_servers_outstanding(net);

}



/*

 * install a server record in the master tree

 */
@@ -81,6 +100,7 @@ static struct afs_server *afs_alloc_server(struct afs_cell *cell, 


		memcpy(&server->addr, addr, sizeof(struct in_addr));

		server->addr.s_addr = addr->s_addr;

		afs_inc_servers_outstanding(cell->net);

		_leave(" = %p{%d}", server, atomic_read(&server->usage));

	} else {

		_leave(" = NULL [nomem]");
@@ -159,6 +179,7 @@ struct afs_server *afs_lookup_server(struct afs_cell *cell, 
server_in_two_cells:

	write_unlock(&cell->servers_lock);

	kfree(candidate);

	afs_dec_servers_outstanding(cell->net);

	printk(KERN_NOTICE "kAFS: Server %pI4 appears to be in two cells\n",

	       addr);

	_leave(" = -EEXIST");
@@ -208,6 +229,18 @@ struct afs_server *afs_find_server(struct afs_net *net, 
	return server;

}



static void afs_set_server_timer(struct afs_net *net, time64_t delay)

{

	afs_inc_servers_outstanding(net);

	if (net->live) {

		if (timer_reduce(&net->server_timer, jiffies + delay * HZ))

			afs_dec_servers_outstanding(net);

	} else {

		if (!queue_work(afs_wq, &net->server_reaper))

			afs_dec_servers_outstanding(net);

	}

}



/*

 * destroy a server record

 * - removes from the cell list
@@ -236,8 +269,7 @@ void afs_put_server(struct afs_server *server) 
	if (atomic_read(&server->usage) == 0) {

		list_move_tail(&server->grave, &net->server_graveyard);

		server->time_of_death = ktime_get_real_seconds();

		queue_delayed_work(afs_wq, &net->server_reaper,

				   net->live ? afs_server_timeout * HZ : 0);

		afs_set_server_timer(net, afs_server_timeout);

	}

	spin_unlock(&net->server_graveyard_lock);

	_leave(" [dead]");
@@ -246,7 +278,7 @@ void afs_put_server(struct afs_server *server) 
/*

 * destroy a dead server

 */

static void afs_destroy_server(struct afs_server *server)

static void afs_destroy_server(struct afs_net *net, struct afs_server *server)

{

	_enter("%p", server);
@@ -260,6 +292,7 @@ static void afs_destroy_server(struct afs_server *server) 


	afs_put_cell(server->cell);

	kfree(server);

	afs_dec_servers_outstanding(net);

}



/*
@@ -269,7 +302,7 @@ void afs_reap_server(struct work_struct *work) 
{

	LIST_HEAD(corpses);

	struct afs_server *server;

	struct afs_net *net = container_of(work, struct afs_net, server_reaper.work);

	struct afs_net *net = container_of(work, struct afs_net, server_reaper);

	unsigned long delay, expiry;

	time64_t now;
@@ -284,8 +317,8 @@ void afs_reap_server(struct work_struct *work) 
		if (net->live) {

			expiry = server->time_of_death + afs_server_timeout;

			if (expiry > now) {

				delay = (expiry - now) * HZ;

				mod_delayed_work(afs_wq, &net->server_reaper, delay);

				delay = (expiry - now);

				afs_set_server_timer(net, delay);

				break;

			}

		}
@@ -309,8 +342,10 @@ void afs_reap_server(struct work_struct *work) 
	while (!list_empty(&corpses)) {

		server = list_entry(corpses.next, struct afs_server, grave);

		list_del(&server->grave);

		afs_destroy_server(server);

		afs_destroy_server(net, server);

	}



	afs_dec_servers_outstanding(net);

}



/*
@@ -319,5 +354,13 @@ void afs_reap_server(struct work_struct *work) 
 */

void __net_exit afs_purge_servers(struct afs_net *net)

{

	mod_delayed_work(afs_wq, &net->server_reaper, 0);

	if (del_timer_sync(&net->server_timer))

		atomic_dec(&net->servers_outstanding);



	afs_inc_servers_outstanding(net);

	if (!queue_work(afs_wq, &net->server_reaper))

		afs_dec_servers_outstanding(net);



	wait_on_atomic_t(&net->servers_outstanding, atomic_t_wait,

			 TASK_UNINTERRUPTIBLE);

}