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Commit cda1fd4a authored by NeilBrown's avatar NeilBrown Committed by Linus Torvalds
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[PATCH] knfsd: fix recently introduced problem with shutting down a busy NFS server 



When the last thread of nfsd exits, it shuts down all related sockets.  It
currently uses svc_close_socket to do this, but that only is immediately
effective if the socket is not SK_BUSY.

If the socket is busy - i.e.  if a request has arrived that has not yet been
processes - svc_close_socket is not effective and the shutdown process spins.

So create a new svc_force_close_socket which removes the SK_BUSY flag is set
and then calls svc_close_socket.

Also change some open-codes loops in svc_destroy to use
list_for_each_entry_safe.

Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5a05ed73

include/linux/sunrpc/svcsock.h

+1 −1
Original line number Diff line number Diff line
@@ -66,7 +66,7 @@ struct svc_sock { 
 * Function prototypes.

 */

int		svc_makesock(struct svc_serv *, int, unsigned short, int flags);

void		svc_close_socket(struct svc_sock *);

void		svc_force_close_socket(struct svc_sock *);

int		svc_recv(struct svc_rqst *, long);

int		svc_send(struct svc_rqst *);

void		svc_drop(struct svc_rqst *);

net/sunrpc/svc.c

+9 −12
Original line number Diff line number Diff line
@@ -367,6 +367,7 @@ void 
svc_destroy(struct svc_serv *serv)

{

	struct svc_sock	*svsk;

	struct svc_sock *tmp;



	dprintk("svc: svc_destroy(%s, %d)\n",

				serv->sv_program->pg_name,
@@ -382,21 +383,17 @@ svc_destroy(struct svc_serv *serv) 


	del_timer_sync(&serv->sv_temptimer);



	while (!list_empty(&serv->sv_tempsocks)) {

		svsk = list_entry(serv->sv_tempsocks.next,

				  struct svc_sock,

				  sk_list);

		svc_close_socket(svsk);

	}

	list_for_each_entry_safe(svsk, tmp, &serv->sv_tempsocks, sk_list)

		svc_force_close_socket(svsk);



	if (serv->sv_shutdown)

		serv->sv_shutdown(serv);



	while (!list_empty(&serv->sv_permsocks)) {

		svsk = list_entry(serv->sv_permsocks.next,

				  struct svc_sock,

				  sk_list);

		svc_close_socket(svsk);

	}

	list_for_each_entry_safe(svsk, tmp, &serv->sv_permsocks, sk_list)

		svc_force_close_socket(svsk);



	BUG_ON(!list_empty(&serv->sv_permsocks));

	BUG_ON(!list_empty(&serv->sv_tempsocks));



	cache_clean_deferred(serv);

net/sunrpc/svcsock.c

+15 −1
Original line number Diff line number Diff line
@@ -82,6 +82,7 @@ static void svc_delete_socket(struct svc_sock *svsk); 
static void		svc_udp_data_ready(struct sock *, int);

static int		svc_udp_recvfrom(struct svc_rqst *);

static int		svc_udp_sendto(struct svc_rqst *);

static void		svc_close_socket(struct svc_sock *svsk);



static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk);

static int svc_deferred_recv(struct svc_rqst *rqstp);
@@ -1787,7 +1788,7 @@ svc_delete_socket(struct svc_sock *svsk) 
	spin_unlock_bh(&serv->sv_lock);

}



void svc_close_socket(struct svc_sock *svsk)

static void svc_close_socket(struct svc_sock *svsk)

{

	set_bit(SK_CLOSE, &svsk->sk_flags);

	if (test_and_set_bit(SK_BUSY, &svsk->sk_flags))
@@ -1800,6 +1801,19 @@ void svc_close_socket(struct svc_sock *svsk) 
	svc_sock_put(svsk);

}



void svc_force_close_socket(struct svc_sock *svsk)

{

	set_bit(SK_CLOSE, &svsk->sk_flags);

	if (test_bit(SK_BUSY, &svsk->sk_flags)) {

		/* Waiting to be processed, but no threads left,

		 * So just remove it from the waiting list

		 */

		list_del_init(&svsk->sk_ready);

		clear_bit(SK_BUSY, &svsk->sk_flags);

	}

	svc_close_socket(svsk);

}



/**

 * svc_makesock - Make a socket for nfsd and lockd

 * @serv: RPC server structure