From: Xiaoming Ni <nixiaoming@xxxxxxxxxx> Subject: kernel/notifier.c: remove blocking_notifier_chain_cond_register() 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() Link: http://lkml.kernel.org/r/1568861888-34045-4-git-send-email-nixiaoming@xxxxxxxxxx Signed-off-by: Xiaoming Ni <nixiaoming@xxxxxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Anna Schumaker <anna.schumaker@xxxxxxxxxx> Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx> Cc: Chuck Lever <chuck.lever@xxxxxxxxxx> Cc: David S. Miller <davem@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: J. Bruce Fields <bfields@xxxxxxxxxxxx> Cc: Jeff Layton <jlayton@xxxxxxxxxx> Cc: Nadia Derbey <Nadia.Derbey@xxxxxxxx> Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx> Cc: Sam Protsenko <semen.protsenko@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx> Cc: Vasily Averin <vvs@xxxxxxxxxxxxx> Cc: Viresh Kumar <viresh.kumar@xxxxxxxxxx> Cc: YueHaibing <yuehaibing@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/notifier.h | 4 ---- kernel/notifier.c | 23 ----------------------- net/sunrpc/rpc_pipe.c | 2 +- 3 files changed, 1 insertion(+), 28 deletions(-) --- a/include/linux/notifier.h~kernel-notifierc-remove-blocking_notifier_chain_cond_register +++ a/include/linux/notifier.h @@ -150,10 +150,6 @@ extern int raw_notifier_chain_register(s 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, --- a/kernel/notifier.c~kernel-notifierc-remove-blocking_notifier_chain_cond_register +++ a/kernel/notifier.c @@ -221,29 +221,6 @@ int blocking_notifier_chain_register(str 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 --- a/net/sunrpc/rpc_pipe.c~kernel-notifierc-remove-blocking_notifier_chain_cond_register +++ a/net/sunrpc/rpc_pipe.c @@ -51,7 +51,7 @@ static BLOCKING_NOTIFIER_HEAD(rpc_pipefs 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); _
