From cda1fd4abd773216a888487af0170d0cc3d50454 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Tue, 6 Mar 2007 01:42:22 -0800
Subject: [PATCH] [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: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
include/linux/sunrpc/svcsock.h | 2 +-
net/sunrpc/svc.c | 21 +++++++++------------
net/sunrpc/svcsock.c | 16 +++++++++++++++-
3 files changed, 25 insertions(+), 14 deletions(-)
diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
index cccea0a0feb4..7909687557bf 100644
--- a/include/linux/sunrpc/svcsock.h
+++ b/include/linux/sunrpc/svcsock.h
@@ -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 *);
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 8353829bc5c6..f960b138236f 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -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);
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index e957ce55fd91..f6e1eb1ea720 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -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
--
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