Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a5001a0d authored by Davidlohr Bueso's avatar Davidlohr Bueso Committed by Linus Torvalds
Browse files

ipc,msg: introduce lockless functions to obtain the ipc object 



Add msq_obtain_object() and msq_obtain_object_check(), which will allow
us to get the ipc object without acquiring the lock.  Just as with
semaphores, these functions are basically wrappers around
ipc_obtain_object*().

Signed-off-by: default avatarDavidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2cafed30

ipc/msg.c

+21 −0
Original line number Diff line number Diff line
@@ -166,6 +166,27 @@ static inline struct msg_queue *msg_lock_check(struct ipc_namespace *ns, 
	return container_of(ipcp, struct msg_queue, q_perm);

}



static inline struct msg_queue *msq_obtain_object(struct ipc_namespace *ns, int id)

{

	struct kern_ipc_perm *ipcp = ipc_obtain_object(&msg_ids(ns), id);



	if (IS_ERR(ipcp))

		return ERR_CAST(ipcp);



	return container_of(ipcp, struct msg_queue, q_perm);

}



static inline struct msg_queue *msq_obtain_object_check(struct ipc_namespace *ns,

							int id)

{

	struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&msg_ids(ns), id);



	if (IS_ERR(ipcp))

		return ERR_CAST(ipcp);



	return container_of(ipcp, struct msg_queue, q_perm);

}



static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)

{

	ipc_rmid(&msg_ids(ns), &s->q_perm);