[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>
diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
index cccea0a..79096875 100644
--- a/include/linux/sunrpc/svcsock.h
+++ b/include/linux/sunrpc/svcsock.h
@@ -66,7 +66,7 @@
  * 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 *);