[PATCH] knfsd: add svc_get

add svc_get() for those occasions when we need to temporarily bump up
svc_serv->sv_nrthreads as a pseudo refcount.

Signed-off-by: Greg Banks <gnb@melbourne.sgi.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 12 insertions, 1 deletions

diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index cdec3993e0d5..9773f593b3ff 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -200,7 +200,7 @@ int nfsd_create_serv(void)
         int err = 0;
         lock_kernel();
         if (nfsd_serv) {
-                nfsd_serv->sv_nrthreads++;
+                svc_get(nfsd_serv);
                 unlock_kernel();
                 return 0;
         }
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index c27d806af310..54d8e7bc2341 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -71,6 +71,17 @@ struct svc_serv {
 };
 
 /*
+ * We use sv_nrthreads as a reference count.  svc_destroy() drops
+ * this refcount, so we need to bump it up around operations that
+ * change the number of threads.  Horrible, but there it is.
+ * Should be called with the BKL held.
+ */
+static inline void svc_get(struct svc_serv *serv)
+{
+        serv->sv_nrthreads++;
+}
+
+/*
  * Maximum payload size supported by a kernel RPC server.
  * This is use to determine the max number of pages nfsd is
  * willing to return in a single READ operation.