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| author | Davidlohr Bueso <davidlohr.bueso@hp.com> | 2013-07-08 16:01:15 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-09 10:33:27 -0700 |
| commit | a5001a0d9768568de5d613c3b3a5b9c7721299da (patch) | |
| tree | 8bdb9f698da1f9e1469322892ba6f6e7c796533b /ipc | |
| parent | 2cafed30f150f7314f98717b372df8173516cae0 (diff) | |
| download | linux-a5001a0d9768568de5d613c3b3a5b9c7721299da.tar.gz linux-a5001a0d9768568de5d613c3b3a5b9c7721299da.tar.bz2 linux-a5001a0d9768568de5d613c3b3a5b9c7721299da.zip | |
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: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc')
| -rw-r--r-- | ipc/msg.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/ipc/msg.c b/ipc/msg.c index f45be81f6de9..c53c13716064 100644 --- a/ipc/msg.c +++ b/ipc/msg.c @@ -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); |