[PATCH] NLM: fix a client-side race on blocking locks.
If the lock blocks, the server may send us a GRANTED message that
races with the reply to our LOCK request. Make sure that we catch
the GRANTED by queueing up our request on the nlm_blocked list
before we send off the first LOCK rpc call.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
index 0d9d225..16d4e5a 100644
--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -72,6 +72,8 @@
uint32_t pid;
};
+struct nlm_wait;
+
/*
* Memory chunk for NLM client RPC request.
*/
@@ -81,6 +83,7 @@
struct nlm_host * a_host; /* host handle */
struct nlm_args a_args; /* arguments */
struct nlm_res a_res; /* result */
+ struct nlm_wait * a_block;
char a_owner[NLMCLNT_OHSIZE];
};
@@ -142,7 +145,9 @@
* Lockd client functions
*/
struct nlm_rqst * nlmclnt_alloc_call(void);
-int nlmclnt_block(struct nlm_host *, struct file_lock *, u32 *);
+int nlmclnt_prepare_block(struct nlm_rqst *req, struct nlm_host *host, struct file_lock *fl);
+void nlmclnt_finish_block(struct nlm_rqst *req);
+long nlmclnt_block(struct nlm_rqst *req, long timeout);
int nlmclnt_cancel(struct nlm_host *, struct file_lock *);
u32 nlmclnt_grant(struct nlm_lock *);
void nlmclnt_recovery(struct nlm_host *, u32);