SUNRPC/NFSD: clean up get/put functions.

svc_destroy() is poorly named - it doesn't necessarily destroy the svc,
it might just reduce the ref count.
nfsd_destroy() is poorly named for the same reason.

This patch:
 - removes the refcount functionality from svc_destroy(), moving it to
   a new svc_put().  Almost all previous callers of svc_destroy() now
   call svc_put().
 - renames nfsd_destroy() to nfsd_put() and improves the code, using
   the new svc_destroy() rather than svc_put()
 - removes a few comments that explain the important for balanced
   get/put calls.  This should be obvious.

The only non-trivial part of this is that svc_destroy() would call
svc_sock_update() on a non-final decrement.  It can no longer do that,
and svc_put() isn't really a good place of it.  This call is now made
from svc_exit_thread() which seems like a good place.  This makes the
call *before* sv_nrthreads is decremented rather than after.  This
is not particularly important as the call just sets a flag which
causes sv_nrthreads set be checked later.  A subsequent patch will
improve the ordering.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

1 files changed, 1 insertions, 5 deletions

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 2f50d5b2a8a4..135bd86ed3ad 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -431,10 +431,6 @@ static struct svc_serv *lockd_create_svc(void)
 	 * Check whether we're already up and running.
 	 */
 	if (nlmsvc_rqst)
-		/*
-		 * Note: increase service usage, because later in case of error
-		 * svc_destroy() will be called.
-		 */
 		return svc_get(nlmsvc_rqst->rq_server);
 
 	/*
@@ -495,7 +491,7 @@ int lockd_up(struct net *net, const struct cred *cred)
 	 * so we exit through here on both success and failure.
 	 */
 err_put:
-	svc_destroy(serv);
+	svc_put(serv);
 err_create:
 	mutex_unlock(&nlmsvc_mutex);
 	return error;