Add shm_obtain_object() and shm_obtain_object_check(), which will allow us to get the ipc object without acquiring the lock. Just as with other forms of ipc, these functions are basically wrappers around ipc_obtain_object*().
Signed-off-by: Davidlohr Bueso <[email protected]> --- ipc/shm.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/ipc/shm.c b/ipc/shm.c index c6b4ad5..216ae72 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -124,6 +124,26 @@ void __init shm_init (void) IPC_SHM_IDS, sysvipc_shm_proc_show); } +static inline struct shmid_kernel *shm_obtain_object(struct ipc_namespace *ns, int id) +{ + struct kern_ipc_perm *ipcp = ipc_obtain_object(&shm_ids(ns), id); + + if (IS_ERR(ipcp)) + return ERR_CAST(ipcp); + + return container_of(ipcp, struct shmid_kernel, shm_perm); +} + +static inline struct shmid_kernel *shm_obtain_object_check(struct ipc_namespace *ns, int id) +{ + struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&shm_ids(ns), id); + + if (IS_ERR(ipcp)) + return ERR_CAST(ipcp); + + return container_of(ipcp, struct shmid_kernel, shm_perm); +} + /* * shm_lock_(check_) routines are called in the paths where the rw_mutex * is not necessarily held. -- 1.7.11.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
