NLM/lockd: Add a reference counter to struct nlm_rqst

When we replace the existing synchronous RPC calls with asynchronous calls,
the reference count will be needed in order to allow us to examine the
result of the RPC call.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 4 insertions, 0 deletions

diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
index 4e1c0123b45d..749eb5328cb0 100644
--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -221,6 +221,7 @@ struct nlm_rqst *nlm_alloc_call(struct nlm_host *host)
         for(;;) {
                 call = kzalloc(sizeof(*call), GFP_KERNEL);
                 if (call != NULL) {
+                        atomic_set(&call->a_count, 1);
                         locks_init_lock(&call->a_args.lock.fl);
                         locks_init_lock(&call->a_res.lock.fl);
                         call->a_host = host;
@@ -237,6 +238,8 @@ struct nlm_rqst *nlm_alloc_call(struct nlm_host *host)
 
 void nlm_release_call(struct nlm_rqst *call)
 {
+        if (!atomic_dec_and_test(&call->a_count))
+                return;
         nlm_release_host(call->a_host);
         nlmclnt_release_lockargs(call);
         kfree(call);
diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
index acf39e1e3a3d..94649a8da014 100644
--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -91,6 +91,7 @@ struct nlm_wait;
  */
 #define NLMCLNT_OHSIZE          ((__NEW_UTS_LEN) + 10u)
 struct nlm_rqst {
+        atomic_t                a_count;
         unsigned int            a_flags;        /* initial RPC task flags */
         struct nlm_host *       a_host;         /* host handle */
         struct nlm_args         a_args;         /* arguments */