[PATCH v2 3/3] kernel/notifier.c: remove blocking_notifier_chain_cond_register()

From: Xiaoming Ni
Date: Thu Jun 20 2019 - 08:54:12 EST


blocking_notifier_chain_cond_register() does not consider
system_booting state, which is the only difference between this
function and blocking_notifier_cain_register(). This can be a bug
and is a piece of duplicate code.

Delete blocking_notifier_chain_cond_register()

Signed-off-by: Xiaoming Ni <nixiaoming@xxxxxxxxxx>
---
include/linux/notifier.h | 4 ----
kernel/notifier.c | 23 -----------------------
net/sunrpc/rpc_pipe.c | 2 +-
3 files changed, 1 insertion(+), 28 deletions(-)

diff --git a/include/linux/notifier.h b/include/linux/notifier.h
index 0096a05..0189476 100644
--- a/include/linux/notifier.h
+++ b/include/linux/notifier.h
@@ -150,10 +150,6 @@ extern int raw_notifier_chain_register(struct raw_notifier_head *nh,
extern int srcu_notifier_chain_register(struct srcu_notifier_head *nh,
struct notifier_block *nb);

-extern int blocking_notifier_chain_cond_register(
- struct blocking_notifier_head *nh,
- struct notifier_block *nb);
-
extern int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh,
struct notifier_block *nb);
extern int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh,
diff --git a/kernel/notifier.c b/kernel/notifier.c
index e3d221f..63d7501 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -221,29 +221,6 @@ int blocking_notifier_chain_register(struct blocking_notifier_head *nh,
EXPORT_SYMBOL_GPL(blocking_notifier_chain_register);

/**
- * blocking_notifier_chain_cond_register - Cond add notifier to a blocking notifier chain
- * @nh: Pointer to head of the blocking notifier chain
- * @n: New entry in notifier chain
- *
- * Adds a notifier to a blocking notifier chain, only if not already
- * present in the chain.
- * Must be called in process context.
- *
- * Currently always returns zero.
- */
-int blocking_notifier_chain_cond_register(struct blocking_notifier_head *nh,
- struct notifier_block *n)
-{
- int ret;
-
- down_write(&nh->rwsem);
- ret = notifier_chain_register(&nh->head, n);
- up_write(&nh->rwsem);
- return ret;
-}
-EXPORT_SYMBOL_GPL(blocking_notifier_chain_cond_register);
-
-/**
* blocking_notifier_chain_unregister - Remove notifier from a blocking notifier chain
* @nh: Pointer to head of the blocking notifier chain
* @n: Entry to remove from notifier chain
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 126d314..1287f80 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -50,7 +50,7 @@

int rpc_pipefs_notifier_register(struct notifier_block *nb)
{
- return blocking_notifier_chain_cond_register(&rpc_pipefs_notifier_list, nb);
+ return blocking_notifier_chain_register(&rpc_pipefs_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(rpc_pipefs_notifier_register);

--
1.8.5.6